NAME
openssl
—
OpenSSL command line tool
SYNOPSIS
openssl |
command [command_opts]
[command_args] |
openssl |
list-standard-commands |
list-message-digest-commands |
list-cipher-commands |
list-cipher-algorithms |
list-message-digest-algorithms |
list-public-key-algorithms |
openssl |
no- XXX
[arbitrary options] |
DESCRIPTION
OpenSSL
is a cryptography toolkit
implementing the Transport Layer Security (TLS v1) network protocol, as well
as related cryptography standards.
The openssl
program is a
command line tool for using the various cryptography functions of
OpenSSL
's
crypto library
from the shell. It can be used for
- Creation and management of private keys, public keys, and parameters
- Public key cryptographic operations
- Creation of X.509 certificates, CSRs and CRLs
- Calculation of Message Digests
- Encryption and Decryption with Ciphers
- SSL/TLS Client and Server Tests
- Handling of S/MIME signed or encrypted mail
- Time stamp requests, generation, and verification
COMMAND SUMMARY
The openssl
program provides a rich
variety of commands (command
in the
SYNOPSIS above), each of which often has
a wealth of options and arguments (command_opts and
command_args in the
SYNOPSIS).
The pseudo-commands
list-standard-commands
,
list-message-digest-commands
, and
list-cipher-commands
output a list (one entry per
line) of the names of all standard commands, message digest commands, or
cipher commands, respectively, that are available in the present
openssl
utility.
The pseudo-commands list-cipher-algorithms
and list-message-digest-algorithms
list all cipher
and message digest names, one entry per line. Aliases are listed as:
The pseudo-command
list-public-key-algorithms
lists all supported
public key algorithms.
The pseudo-command
no-
XXX tests whether a command
of the specified name is available. If no command named
XXX exists, it returns 0 (success) and prints
no-
XXX; otherwise it returns 1
and prints XXX. In both cases, the output goes to
stdout and nothing
is printed to
stderr.
Additional command line arguments are always ignored. Since for each cipher
there is a command of the same name, this provides an easy way for shell
scripts to test for the availability of ciphers in the
openssl
program.
Note:
no-
XXX is not able to detect
pseudo-commands such as quit
,
list-
...-commands
,
or no-
XXX itself.
STANDARD COMMANDS
asn1parse
- Parse an ASN.1 sequence.
ca
- Certificate Authority (CA) management.
ciphers
- Cipher suite description determination.
crl
- Certificate Revocation List (CRL) management.
crl2pkcs7
- CRL to PKCS#7 conversion.
dgst
- Message digest calculation.
dh
- Diffie-Hellman parameter management. Obsoleted by
dhparam
. dhparam
- Generation and management of Diffie-Hellman parameters. Superseded by
genpkey
andpkeyparam
. dsa
- DSA data management.
dsaparam
- DSA parameter generation and management. Superseded by
genpkey
andpkeyparam
. ec
- Elliptic curve (EC) key processing.
ecparam
- EC parameter manipulation and generation.
enc
- Encoding with ciphers.
errstr
- Error number to error string conversion.
gendh
- Generation of Diffie-Hellman parameters. Obsoleted by
dhparam
. gendsa
- Generation of DSA private key from parameters. Superseded by
genpkey
andpkey
. genpkey
- Generation of private keys or parameters.
genrsa
- Generation of RSA private key. Superseded by
genpkey
. nseq
- Create or examine a Netscape certificate sequence.
ocsp
- Online Certificate Status Protocol utility.
passwd
- Generation of hashed passwords.
pkcs7
- PKCS#7 data management.
pkcs8
- PKCS#8 data management.
pkcs12
- PKCS#12 data management.
pkey
- Public and private key management.
pkeyparam
- Public key algorithm parameter management.
pkeyutl
- Public key algorithm cryptographic operation utility.
prime
- Generate prime numbers or test numbers for primality.
rand
- Generate pseudo-random bytes.
req
- PKCS#10 X.509 Certificate Signing Request (CSR) management.
rsa
- RSA key management.
rsautl
- RSA utility for signing, verification, encryption, and decryption.
Superseded by
pkeyutl
. s_client
- This implements a generic SSL/TLS client which can establish a transparent
connection to a remote server speaking SSL/TLS. It's intended for testing
purposes only and provides only rudimentary interface functionality but
internally uses mostly all functionality of the
OpenSSL
ssl library. s_server
- This implements a generic SSL/TLS server which accepts connections from
remote clients speaking SSL/TLS. It's intended for testing purposes only
and provides only rudimentary interface functionality but internally uses
mostly all functionality of the
OpenSSL
ssl library. It provides both an own command line oriented protocol for testing SSL functions and a simple HTTP response facility to emulate an SSL/TLS-aware webserver. s_time
- SSL connection timer.
sess_id
- SSL session data management.
smime
- S/MIME mail processing.
speed
- Algorithm speed measurement.
spkac
- SPKAC printing and generating utility.
ts
- Time stamping authority tool (client/server).
verify
- X.509 certificate verification.
version
OpenSSL
version information.x509
- X.509 certificate data management.
MESSAGE DIGEST COMMANDS
gost-mac
- GOST-MAC digest.
streebog256
- Streebog-256 digest.
streebog512
- Streebog-512 digest.
md_gost94
- GOST R 34.11-94 digest.
md4
- MD4 digest.
md5
- MD5 digest.
ripemd160
- RIPEMD-160 digest.
sha
- SHA digest.
sha1
- SHA-1 digest.
sha224
- SHA-224 digest.
sha256
- SHA-256 digest.
sha384
- SHA-384 digest.
sha512
- SHA-512 digest.
whirlpool
- Whirlpool digest.
ENCODING AND CIPHER COMMANDS
aes-128-cbc
|aes-128-ecb
|aes-192-cbc
|aes-192-ecb
aes-256-cbc
|aes-256-ecb
- AES cipher.
base64
- Base64 encoding.
bf
|bf-cbc
|bf-cfb
|bf-ecb
|bf-ofb
- Blowfish cipher.
cast
|cast-cbc
- CAST cipher.
cast5-cbc
|cast5-cfb
|cast5-ecb
|cast5-ofb
- CAST5 cipher.
des
|des-cbc
|des-cfb
|des-ecb
|des-ede
|des-ede-cbc
des-ede-cfb
|des-ede-ofb
|des-ofb
- DES cipher.
des3
|desx
|des-ede3
|des-ede3-cbc
|des-ede3-cfb
|des-ede3-ofb
- Triple DES cipher.
rc2
|rc2-40-cbc
|rc2-64-cbc
|rc2-cbc
|rc2-cfb
|rc2-ecb
|rc2-ofb
- RC2 cipher.
rc4
|rc4-40
- RC4 cipher.
PASS PHRASE ARGUMENTS
Several commands accept password arguments, typically using
-passin
and -passout
for
input and output passwords, respectively. These allow the password to be
obtained from a variety of sources. Both of these options take a single
argument whose format is described below. If no password argument is given
and a password is required, then the user is prompted to enter one: this
will typically be read from the current terminal with echoing turned
off.
- pass:password
- The actual password is password. Since the password is visible to utilities (like ps(1) under UNIX) this form should only be used where security is not important.
- env:var
- Obtain the password from the environment variable var. Since the environment of other processes is visible on certain platforms (e.g. ps(1) under certain UNIX OSes) this option should be used with caution.
- file:path
- The first line of path is the password. If the same
path argument is supplied to
-passin
and-passout
, then the first line will be used for the input password and the next line for the output password. path need not refer to a regular file: it could, for example, refer to a device or named pipe. - fd:number
- Read the password from the file descriptor number. This can be used to send the data via a pipe for example.
- stdin
- Read the password from standard input.
ASN1PARSE
openssl asn1parse |
[-i ]
[-dlimit number]
[-dump ]
[-genconf file]
[-genstr str]
[-in file]
[-inform DER | PEM | TXT]
[-length number]
[-noout ]
[-offset number]
[-oid file]
[-out file]
[-strparse offset] |
The asn1parse
command is a diagnostic
utility that can parse ASN.1 structures. It can also be used to extract data
from ASN.1 formatted data.
The options are as follows:
-dlimit
number- Dump the first number bytes of unknown data in hex form.
-dump
- Dump unknown data in hex form.
-genconf
file,-genstr
str- Generate encoded data based on string str, file
file, or both using
ASN1_generate_nconf(3) format. If only
file is present then the string is obtained from the
default section using the name “asn1”. The encoded data is
passed through the ASN1 parser and printed out as though it came from a
file; the contents can thus be examined and written to a file using the
-out
option. -i
- Indents the output according to the "depth" of the structures.
-in
file- The input file; default is standard input.
-inform
DER | PEM | TXT- The input format. DER (Distinguished Encoding Rules) is binary format and PEM (Privacy Enhanced Mail), the default, is base64-encoded. TXT is plain text.
-length
number- Number of bytes to parse; default is until end of file.
-noout
- Don't output the parsed version of the input file.
-offset
number- Starting offset to begin parsing; default is start of file.
-oid
file- A file containing additional object identifiers (OIDs). The format of this file is described in the ASN1PARSE NOTES section below.
-out
file- Output file to place the DER-encoded data into. If this option is not
present, no encoded data will be output. This is most useful when combined
with the
-strparse
option. -strparse
offset- Parse the content octets of the ASN.1 object starting at offset. This option can be used multiple times to "drill down" into a nested structure.
ASN1PARSE OUTPUT
The output will typically contain lines like this:
0:d=0 hl=4 l= 681 cons: SEQUENCE ..... 229:d=3 hl=3 l= 141 prim: BIT STRING 373:d=2 hl=3 l= 162 cons: cont [ 3 ] 376:d=3 hl=3 l= 159 cons: SEQUENCE 379:d=4 hl=2 l= 29 cons: SEQUENCE 381:d=5 hl=2 l= 3 prim: OBJECT :X509v3 Subject Key Identifier 386:d=5 hl=2 l= 22 prim: OCTET STRING 410:d=4 hl=2 l= 112 cons: SEQUENCE 412:d=5 hl=2 l= 3 prim: OBJECT :X509v3 Authority Key Identifier 417:d=5 hl=2 l= 105 prim: OCTET STRING 524:d=4 hl=2 l= 12 cons: SEQUENCE .....
This example is part of a self-signed certificate. Each line
starts with the offset in decimal. d=XX
specifies
the current depth. The depth is increased within the scope of any SET or
SEQUENCE. hl=XX
gives the header length (tag and
length octets) of the current type. l=XX
gives the
length of the content octets.
The -i
option can be used to make the
output more readable.
Some knowledge of the ASN.1 structure is needed to interpret the output.
In this example, the BIT STRING at offset 229 is the certificate
public key. The content octets of this will contain the public key
information. This can be examined using the option
-strparse
229
to yield:
0:d=0 hl=3 l= 137 cons: SEQUENCE 3:d=1 hl=3 l= 129 prim: INTEGER :E5D21E1F5C8D208EA7A2166C7FA F9F6BDF2059669C60876DDB70840F1A5AAFA59699FE471F379F1DD6A487E7D5409AB6A88D4A 9746E24B91D8CF55DB3521015460C8EDE44EE8A4189F7A7BE77D6CD3A9AF2696F486855CF58 BF0EDF2B4068058C7A947F52548DDF7E15E96B385F86422BEA9064A3EE9 135:d=1 hl=2 l= 3 prim: INTEGER :010001
ASN1PARSE NOTES
If an OID (object identifier) is not part of
OpenSSL
's
internal table it
will be represented in numerical form (for example 1.2.3.4). The file passed
to the -oid
option allows additional OIDs to be
included. Each line consists of three columns: the first column is the OID
in numerical format and should be followed by whitespace. The second column
is the "short name" which is a single word followed by whitespace.
The final column is the rest of the line and is the "long name".
asn1parse
displays the long name. Example:
"1.2.3.4 shortname A long
name"
ASN1 EXAMPLES
Parse a file:
$ openssl asn1parse -in
file.pem
Parse a DER file:
$ openssl asn1parse -inform DER -in
file.der
ASN1PARSE BUGS
There should be options to change the format of output lines. The output of some ASN.1 types is not well handled (if at all).
CA
openssl ca |
[-batch ]
[-cert file]
[-config file]
[-crl_CA_compromise time]
[-crl_compromise time]
[-crl_hold instruction]
[-crl_reason reason]
[-crldays days]
[-crlexts section]
[-crlhours hours]
[-days arg]
[-enddate date]
[-extensions section]
[-extfile section]
[-gencrl ]
[-in file]
[-infiles ]
[-key keyfile]
[-keyfile arg]
[-keyform PEM]
[-md arg]
[-msie_hack ]
[-name section]
[-noemailDN ] [-notext ]
[-out file]
[-outdir dir]
[-passin arg]
[-policy arg]
[-preserveDN ]
[-revoke file]
[-spkac file]
[-ss_cert file]
[-startdate date]
[-status serial]
[-subj arg]
[-updatedb ]
[-verbose ] |
The ca
command is a minimal CA
application. It can be used to sign certificate requests in a variety of
forms and generate CRLs. It also maintains a text database of issued
certificates and their status.
The options descriptions will be divided into each purpose.
CA OPTIONS
-batch
- This sets the batch mode. In this mode no questions will be asked and all certificates will be certified automatically.
-cert
file- The CA certificate file.
-config
file- Specifies the configuration file to use.
-days
arg- The number of days to certify the certificate for.
-enddate
date- This allows the expiry date to be explicitly set. The format of the date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
-extensions
section- The section of the configuration file containing certificate extensions to
be added when a certificate is issued (defaults to
x509_extensions
unless the
-extfile
option is used). If no extension section is present, a V1 certificate is created. If the extension section is present (even if it is empty), then a V3 certificate is created. -extfile
file- An additional configuration file to read certificate
extensions from (using the default section unless the
-extensions
option is also used). -in
file- An input file containing a single certificate request to be signed by the CA.
-infiles
- If present, this should be the last option; all subsequent arguments are assumed to be the names of files containing certificate requests.
-key
keyfile- The password used to encrypt the private key. Since on some systems the command line arguments are visible (e.g. UNIX with the ps(1) utility) this option should be used with caution.
-keyfile
file- The private key to sign requests with.
-keyform
PEM- Private key file format.
-md
alg- The message digest to use. Possible values include md5 and sha1. This option also applies to CRLs.
-msie_hack
- This is a legacy option to make
ca
work with very old versions of the IE certificate enrollment control "certenr3". It used UniversalStrings for almost everything. Since the old control has various security bugs, its use is strongly discouraged. The newer control "Xenroll" does not need this option. -name
section- Specifies the configuration file section to use
(overrides
default_ca
in theca
section). -noemailDN
- The DN of a certificate can contain the EMAIL field if present in the request DN, however it is good policy just having the email set into the altName extension of the certificate. When this option is set, the EMAIL field is removed from the certificate's subject and set only in the, eventually present, extensions. The email_in_dn keyword can be used in the configuration file to enable this behaviour.
-notext
- Don't output the text form of a certificate to the output file.
-out
file- The output file to output certificates to. The default is standard output. The certificate details will also be printed out to this file.
-outdir
directory- The directory to output certificates to. The certificate will be written to a file consisting of the serial number in hex with ".pem" appended.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-policy
arg- This option defines the CA "policy" to use. This is a section in the configuration file which decides which fields should be mandatory or match the CA certificate. Check out the CA POLICY FORMAT section for more information.
-preserveDN
- Normally, the DN order of a certificate is the same as the order of the fields in the relevant policy section. When this option is set, the order is the same as the request. This is largely for compatibility with the older IE enrollment control which would only accept certificates if their DNs matched the order of the request. This is not needed for Xenroll.
-spkac
file- A file containing a single Netscape signed public key and challenge, and additional field values to be signed by the CA. See the SPKAC FORMAT section for information on the required format.
-ss_cert
file- A single self-signed certificate to be signed by the CA.
-startdate
date- This allows the start date to be explicitly set. The format of the date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
-status
serial- Show status of certificate with serial number serial.
-updatedb
- Update database for expired certificates.
-verbose
- This prints extra details about the operations being performed.
CRL OPTIONS
-crl_CA_compromise
time- This is the same as
-crl_compromise
, except the revocation reason is set to CACompromise. -crl_compromise
time- This sets the revocation reason to keyCompromise and the compromise time to time. time should be in GeneralizedTime format, i.e. YYYYMMDDHHMMSSZ.
-crl_hold
instruction- This sets the CRL revocation reason code to certificateHold and the hold instruction to instruction which must be an OID. Although any OID can be used, only holdInstructionNone (the use of which is discouraged by RFC 2459), holdInstructionCallIssuer or holdInstructionReject will normally be used.
-crl_reason
reason- Revocation reason, where reason is one of: unspecified, keyCompromise, CACompromise, affiliationChanged, superseded, cessationOfOperation, certificateHold or removeFromCRL. The matching of reason is case insensitive. Setting any revocation reason will make the CRL v2. In practice, removeFromCRL is not particularly useful because it is only used in delta CRLs which are not currently implemented.
-crldays
num- The number of days before the next CRL is due. This is the days from now to place in the CRL nextUpdate field.
-crlexts
section- The section of the configuration file containing CRL extensions to include. If no CRL extension section is present then a V1 CRL is created; if the CRL extension section is present (even if it is empty) then a V2 CRL is created. The CRL extensions specified are CRL extensions and not CRL entry extensions. It should be noted that some software (for example Netscape) can't handle V2 CRLs.
-crlhours
num- The number of hours before the next CRL is due.
-gencrl
- This option generates a CRL based on information in the index file.
-revoke
file- A file containing a certificate to revoke.
-subj
arg- Supersedes the subject name given in the request. The arg must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash), no spaces are skipped.
CA CONFIGURATION FILE OPTIONS
The section of the configuration file containing options for
ca
is found as follows: If the
-name
command line option is used, then it names the
section to be used. Otherwise the section to be used must be named in the
default_ca option of the ca section of
the configuration file (or in the default section of the configuration
file). Besides default_ca, the following options are read
directly from the ca section:
- preserve
- msie_hack
This is probably a bug and may change in future releases.
Many of the configuration file options are identical to command line options. Where the option is present in the configuration file and the command line, the command line value is used. Where an option is described as mandatory, then it must be present in the configuration file or the command line equivalent (if any) used.
- certificate
- The same as
-cert
. It gives the file containing the CA certificate. Mandatory. - copy_extensions
- Determines how extensions in certificate requests should be handled. If
set to none or this option is not present, then
extensions are ignored and not copied to the certificate. If set to
copy, then any extensions present in the request
that are not already present are copied to the certificate. If set to
copyall, then all extensions in the request are
copied to the certificate: if the extension is already present in the
certificate it is deleted first. See the
CA WARNINGS section before using
this option.
The main use of this option is to allow a certificate request to supply values for certain extensions such as subjectAltName.
- crl_extensions
- The same as
-crlexts
. - crlnumber
- A text file containing the next CRL number to use in hex. The CRL number will be inserted in the CRLs only if this file exists. If this file is present, it must contain a valid CRL number.
- database
- The text database file to use. Mandatory. This file must be present, though initially it will be empty.
- default_crl_hours, default_crl_days
- The same as the
-crlhours
and-crldays
options. These will only be used if neither command line option is present. At least one of these must be present to generate a CRL. - default_days
- The same as the
-days
option. The number of days to certify a certificate for. - default_enddate
- The same as the
-enddate
option. Either this option or default_days (or the command line equivalents) must be present. - default_md
- The same as the
-md
option. The message digest to use. Mandatory. - default_startdate
- The same as the
-startdate
option. The start date to certify a certificate for. If not set, the current time is used. - email_in_dn
- The same as
-noemailDN
. If the EMAIL field is to be removed from the DN of the certificate, simply set this to "no". If not present, the default is to allow for the EMAIL field in the certificate's DN. - msie_hack
- The same as
-msie_hack
. - name_opt, cert_opt
- These options allow the format used to display the certificate details
when asking the user to confirm signing. All the options supported by the
x509
utilities'-nameopt
and-certopt
switches can be used here, except that no_signame and no_sigdump are permanently set and cannot be disabled (this is because the certificate signature cannot be displayed because the certificate has not been signed at this point).For convenience, the value ca_default is accepted by both to produce a reasonable output.
If neither option is present, the format used in earlier versions of
OpenSSL
is used. Use of the old format is strongly discouraged because it only displays fields mentioned in the policy section, mishandles multicharacter string types and does not display extensions. - new_certs_dir
- The same as the
-outdir
command line option. It specifies the directory where new certificates will be placed. Mandatory. - oid_file
- This specifies a file containing additional object identifiers. Each line of the file should consist of the numerical form of the object identifier followed by whitespace, then the short name followed by whitespace and finally the long name.
- oid_section
- This specifies a section in the configuration file containing extra object identifiers. Each line should consist of the short name of the object identifier followed by ‘=’ and the numerical form. The short and long names are the same when this option is used.
- policy
- The same as
-policy
. Mandatory. See the CA POLICY FORMAT section for more information. - preserve
- The same as
-preserveDN
. - private_key
- Same as the
-keyfile
option. The file containing the CA private key. Mandatory. - serial
- A text file containing the next serial number to use in hex. Mandatory. This file must be present and contain a valid serial number.
- unique_subject
- If the value yes is given, the valid certificate entries in the database must have unique subjects. If the value no is given, several valid certificate entries may have the exact same subject. The default value is yes.
- x509_extensions
- The same as
-extensions
.
CA POLICY FORMAT
The policy section consists of a set of variables corresponding to
certificate DN fields. If the value is "match", then the field
value must match the same field in the CA certificate. If the value is
"supplied", then it must be present. If the value is
"optional", then it may be present. Any fields not mentioned in
the policy section are silently deleted, unless the
-preserveDN
option is set, but this can be regarded
more of a quirk than intended behaviour.
SPKAC FORMAT
The input to the -spkac
command line
option is a Netscape signed public key and challenge. This will usually come
from the KEYGEN tag in an HTML form to create a new
private key. It is, however, possible to create SPKACs using the
spkac
utility.
The file should contain the variable SPKAC set to the value of the SPKAC and also the required DN components as name value pairs. If it's necessary to include the same component twice, then it can be preceded by a number and a ‘.’.
CA EXAMPLES
Note: these examples assume that the
ca
directory structure is already set up and the
relevant files already exist. This usually involves creating a CA
certificate and private key with req
, a serial
number file and an empty index file and placing them in the relevant
directories.
To use the sample configuration file below, the directories demoCA, demoCA/private and demoCA/newcerts would be created. The CA certificate would be copied to demoCA/cacert.pem and its private key to demoCA/private/cakey.pem. A file demoCA/serial would be created containing, for example, "01" and the empty index file demoCA/index.txt.
Sign a certificate request:
$ openssl ca -in req.pem -out
newcert.pem
Sign a certificate request, using CA extensions:
$ openssl ca -in req.pem -extensions
v3_ca -out newcert.pem
Generate a CRL:
$ openssl ca -gencrl -out
crl.pem
Sign several requests:
$ openssl ca -infiles req1.pem
req2.pem req3.pem
Certify a Netscape SPKAC:
$ openssl ca -spkac
spkac.txt
A sample SPKAC file (the SPKAC line has been truncated for clarity):
SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK CN=Steve Test emailAddress=steve@openssl.org 0.OU=OpenSSL Group 1.OU=Another Group
A sample configuration file with the relevant sections for
ca
:
[ ca ] default_ca = CA_default # The default ca section [ CA_default ] dir = ./demoCA # top dir database = $dir/index.txt # index file new_certs_dir = $dir/newcerts # new certs dir certificate = $dir/cacert.pem # The CA cert serial = $dir/serial # serial no file private_key = $dir/private/cakey.pem# CA private key default_days = 365 # how long to certify for default_crl_days= 30 # how long before next CRL default_md = md5 # md to use policy = policy_any # default policy email_in_dn = no # Don't add the email into cert DN name_opt = ca_default # Subject name display option cert_opt = ca_default # Certificate display option copy_extensions = none #Don't copy extensions from request [ policy_any ] countryName = supplied stateOrProvinceName = optional organizationName = optional organizationalUnitName = optional commonName = supplied emailAddress = optional
CA FILES
Note: the location of all files can change either by compile time options, configuration file entries, environment variables, or command line options. The values below reflect the default values.
/etc/ssl/openssl.cnf - master configuration file ./demoCA - main CA directory ./demoCA/cacert.pem - CA certificate ./demoCA/private/cakey.pem - CA private key ./demoCA/serial - CA serial number file ./demoCA/serial.old - CA serial number backup file ./demoCA/index.txt - CA text database file ./demoCA/index.txt.old - CA text database backup file ./demoCA/certs - certificate output file
CA ENVIRONMENT VARIABLES
OPENSSL_CONF
reflects the location of the
master configuration file; it can be overridden by the
-config
command line option.
CA RESTRICTIONS
The text database index file is a critical part of the process, and if corrupted it can be difficult to fix. It is theoretically possible to rebuild the index file from all the issued certificates and a current CRL; however there is no option to do this.
V2 CRL features like delta CRLs are not currently supported.
Although several requests can be input and handled at once, it is only possible to include one SPKAC or self-signed certificate.
CA BUGS
The use of an in-memory text database can cause problems when large numbers of certificates are present because, as the name implies, the database has to be kept in memory.
It is not possible to certify two certificates with the same DN; this is a side effect of how the text database is indexed and it cannot easily be fixed without introducing other problems. Some S/MIME clients can use two certificates with the same DN for separate signing and encryption keys.
The ca
command really needs rewriting or
the required functionality exposed at either a command or interface level so
a more friendly utility (perl script or GUI) can handle things properly.
Any fields in a request that are not present in a policy are
silently deleted. This does not happen if the
-preserveDN
option is used. To enforce the absence
of the EMAIL field within the DN, as suggested by RFCs, regardless of the
contents of the request's subject the -noemailDN
option can be used. The behaviour should be more friendly and
configurable.
Cancelling some commands by refusing to certify a certificate can create an empty file.
CA WARNINGS
The ca
command is quirky and at times
downright unfriendly.
The ca
utility was originally meant as an
example of how to do things in a CA. It was not supposed to be used as a
full blown CA itself: nevertheless some people are using it for this
purpose.
The ca
command is effectively a single
user command: no locking is done on the various files, and attempts to run
more than one ca
command on the same database can
have unpredictable results.
The copy_extensions option should be used with caution. If care is not taken, it can be a security risk. For example, if a certificate request contains a basicConstraints extension with CA:TRUE and the copy_extensions value is set to copyall and the user does not spot this when the certificate is displayed, then this will hand the requestor a valid CA certificate.
This situation can be avoided by setting copy_extensions to copy and including basicConstraints with CA:FALSE in the configuration file. Then if the request contains a basicConstraints extension, it will be ignored.
It is advisable to also include values for other extensions such as keyUsage to prevent a request supplying its own values.
Additional restrictions can be placed on the CA certificate itself. For example if the CA certificate has:
then even if a certificate is issued with CA:TRUE it will not be valid.
CIPHERS
openssl ciphers
[-hVv
] [-tls1
]
[cipherlist]
The ciphers
command converts
OpenSSL
cipher lists into ordered SSL cipher
preference lists. It can be used as a test tool to determine the appropriate
cipherlist.
The options are as follows:
-h
,-?
- Print a brief usage message.
-tls1
- Only include TLS v1 ciphers.
-V
- Like
-v
, but include cipher suite codes in output (hex format). -v
- Verbose option. List ciphers with a complete description of protocol
version, key exchange, authentication, encryption and mac algorithms used
along with any key size restrictions. Note that without the
-v
option, ciphers may seem to appear twice in a cipher list. - cipherlist
- A cipher list to convert to a cipher preference list. If it is not included, the default cipher list will be used. The format is described below.
CIPHERS LIST FORMAT
The cipher list consists of one or more cipher strings separated by colons. Commas or spaces are also acceptable separators, but colons are normally used.
The actual cipher string can take several different forms:
It can consist of a single cipher suite such as RC4-SHA.
It can represent a list of cipher suites containing a certain algorithm, or cipher suites of a certain type. For example SHA1 represents all cipher suites using the digest algorithm SHA1.
Lists of cipher suites can be combined in a single cipher string using the ‘+’ character. This is used as a logical and operation. For example, SHA1+DES represents all cipher suites containing the SHA1 and the DES algorithms.
Each cipher string can be optionally preceded by the characters ‘!’, ‘-’, or ‘+’.
If ‘!’ is used, then the ciphers are permanently deleted from the list. The ciphers deleted can never reappear in the list even if they are explicitly stated.
If ‘-’ is used, then the ciphers are deleted from the list, but some or all of the ciphers can be added again by later options.
If ‘+’ is used, then the ciphers are moved to the end of the list. This option doesn't add any new ciphers, it just moves matching existing ones.
If none of these characters is present, the string is just interpreted as a list of ciphers to be appended to the current preference list. If the list includes any ciphers already present, they will be ignored; that is, they will not be moved to the end of the list.
Additionally, the cipher string @STRENGTH can be used at any point to sort the current cipher list in order of encryption algorithm key length.
CIPHERS STRINGS
The following is a list of all permitted cipher strings and their meanings.
- DEFAULT
- The default cipher list. This is determined at compile time and is currently ALL:!aNULL:!eNULL:!SSLv2. This must be the first cipher string specified.
- COMPLEMENTOFDEFAULT
- The ciphers included in ALL, but not enabled by default. Currently this is ADH. Note that this rule does not cover eNULL, which is not included by ALL (use COMPLEMENTOFALL if necessary).
- ALL
- All cipher suites except the eNULL ciphers which must be explicitly enabled.
- COMPLEMENTOFALL
- The cipher suites not enabled by ALL, currently being eNULL.
- HIGH
- "High" encryption cipher suites. This currently means those with key lengths larger than 128 bits.
- MEDIUM
- "Medium" encryption cipher suites, currently those using 128-bit encryption.
- LOW
- "Low" encryption cipher suites, currently those using 64- or 56-bit encryption algorithms.
- eNULL, NULL
- The "NULL" ciphers; that is, those offering no encryption. Because these offer no encryption at all and are a security risk, they are disabled unless explicitly included.
- aNULL
- The cipher suites offering no authentication. This is currently the anonymous DH algorithms. These cipher suites are vulnerable to a "man in the middle" attack, so their use is normally discouraged.
- kRSA, RSA
- Cipher suites using RSA key exchange.
- kEDH
- Cipher suites using ephemeral DH key agreement.
- aRSA
- Cipher suites using RSA authentication, i.e. the certificates carry RSA keys.
- aDSS, DSS
- Cipher suites using DSS authentication, i.e. the certificates carry DSS keys.
- TLSv1
- TLS v1.0 cipher suites.
- DH
- Cipher suites using DH, including anonymous DH.
- ADH
- Anonymous DH cipher suites.
- AES
- Cipher suites using AES.
- 3DES
- Cipher suites using triple DES.
- DES
- Cipher suites using DES (not triple DES).
- RC4
- Cipher suites using RC4.
- CAMELLIA
- Cipher suites using Camellia.
- CHACHA20
- Cipher suites using ChaCha20.
- IDEA
- Cipher suites using IDEA.
- MD5
- Cipher suites using MD5.
- SHA1, SHA
- Cipher suites using SHA1.
CIPHERS EXAMPLES
Verbose listing of all OpenSSL
ciphers
including NULL ciphers:
$ openssl ciphers -v
'ALL:eNULL'
Include all ciphers except NULL and anonymous DH then sort by strength:
$ openssl ciphers -v
'ALL:!ADH:@STRENGTH'
Include only 3DES ciphers and then place RSA ciphers last:
$ openssl ciphers -v
'3DES:+RSA'
Include all RC4 ciphers but leave out those without authentication:
$ openssl ciphers -v
'RC4:!COMPLEMENTOFDEFAULT'
Include all ciphers with RSA authentication but leave out ciphers without encryption:
$ openssl ciphers -v
'RSA:!COMPLEMENTOFALL'
CRL
openssl crl |
[-CAfile file]
[-CApath dir]
[-fingerprint ] [-hash ]
[-in file]
[-inform DER | PEM]
[-issuer ] [-lastupdate ]
[-nextupdate ] [-noout ]
[-out file]
[-outform DER | PEM]
[-text ] |
The crl
command processes CRL files in DER
or PEM format.
The options are as follows:
-CAfile
file- Verify the signature on a CRL by looking up the issuing certificate in file.
-CApath
directory- Verify the signature on a CRL by looking up the issuing certificate in
dir. This directory must be a standard certificate
directory, i.e. a hash of each subject name (using
x509
-hash
) should be linked to each certificate. -fingerprint
- Print the CRL fingerprint.
-hash
- Output a hash of the issuer name. This can be used to look up CRLs in a directory by issuer name.
-in
file- This specifies the input file to read from, or standard input if this option is not specified.
-inform
DER | PEM- This specifies the input format. DER format is a DER-encoded CRL structure. PEM (the default) is a base64-encoded version of the DER form with header and footer lines.
-issuer
- Output the issuer name.
-lastupdate
- Output the lastUpdate field.
-nextupdate
- Output the nextUpdate field.
-noout
- Don't output the encoded version of the CRL.
-out
file- Specifies the output file to write to, or standard output by default.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -text
- Print out the CRL in text form.
CRL NOTES
The PEM CRL format uses the header and footer lines:
-----BEGIN X509 CRL----- -----END X509 CRL-----
CRL EXAMPLES
Convert a CRL file from PEM to DER:
$ openssl crl -in crl.pem -outform
DER -out crl.der
Output the text form of a DER-encoded certificate:
$ openssl crl -in crl.der -inform DER
-text -noout
CRL BUGS
Ideally, it should be possible to create a CRL using appropriate options and files too.
CRL2PKCS7
openssl crl2pkcs7 |
[-certfile file]
[-in file]
[-inform DER | PEM]
[-nocrl ]
[-out file]
[-outform DER | PEM] |
The crl2pkcs7
command takes an optional
CRL and one or more certificates and converts them into a PKCS#7 degenerate
"certificates only" structure.
The options are as follows:
-certfile
file- Specifies a file containing one or more certificates in PEM format. All certificates in the file will be added to the PKCS#7 structure. This option can be used more than once to read certificates from multiple files.
-in
file- This specifies the input file to read a CRL from, or standard input if this option is not specified.
-inform
DER | PEM- This specifies the CRL input format. DER format is a DER-encoded CRL structure. PEM (the default) is a base64-encoded version of the DER form with header and footer lines.
-nocrl
- Normally, a CRL is included in the output file. With this option, no CRL is included in the output file and a CRL is not read from the input file.
-out
file- Specifies the output file to write the PKCS#7 structure to, or standard output by default.
-outform
DER | PEM- This specifies the PKCS#7 structure output format. DER format is a DER-encoded PKCS#7 structure. PEM (the default) is a base64-encoded version of the DER form with header and footer lines.
CRL2PKCS7 EXAMPLES
Create a PKCS#7 structure from a certificate and CRL:
$ openssl crl2pkcs7 -in crl.pem
-certfile cert.pem -out p7.pem
Create a PKCS#7 structure in DER format with no CRL from several different certificates:
$ openssl crl2pkcs7 -nocrl -certfile newcert.pem \ -certfile demoCA/cacert.pem -outform DER -out p7.der
CRL2PKCS7 NOTES
The output file is a PKCS#7 signed data structure containing no signers and just certificates and an optional CRL.
This utility can be used to send certificates and CAs to Netscape as part of the certificate enrollment process. This involves sending the DER-encoded output as MIME type application/x-x509-user-cert.
The PEM-encoded form with the header and footer lines removed can be used to install user certificates and CAs in MSIE using the Xenroll control.
DGST
openssl dgst |
[-gost-mac
| -streebog256 | -streebog512 | -md_gost94 | -md4
| -md5 | -ripemd160 | -sha1 | -sha224
| -sha256 | -sha384 | -sha512 | -whirlpool ]
[-binary ] [-cd ]
[-hex ]
[-hmac key]
[-keyform PEM]
[-mac algorithm]
[-macopt nm:v]
[-out file]
[-passin arg]
[-prverify file]
[-sign file]
[-signature file]
[-sigopt nm:v]
[-verify file]
[file ...] |
openssl
gost-mac
|
streebog256
| streebog512
|
md_gost94
| md4
|
md5
| ripemd160
|
sha1
| sha224
|
sha256
| sha384
|
sha512
| whirlpool
[-c
] [-d
]
[file ...]
The digest functions output the message digest of a supplied file or files in hexadecimal form. They can also be used for digital signing and verification.
The options are as follows:
-binary
- Output the digest or signature in binary form.
-c
- Print out the digest in two-digit groups separated by colons; only relevant if hex format output is used.
-d
- Print out BIO debugging information.
-hex
- Digest is to be output as a hex dump. This is the default case for a "normal" digest as opposed to a digital signature.
-hmac
key- Create a hashed MAC using key.
-keyform
PEM- Specifies the key format to sign the digest with.
-mac
algorithm- Create a keyed Message Authentication Code (MAC). The most popular MAC
algorithm is HMAC (hash-based MAC), but there are other MAC algorithms
which are not based on hash. MAC keys and other options should be set via
the
-macopt
parameter. -macopt
nm:v- Passes options to the MAC algorithm, specified by
-mac
. The following options are supported by HMAC:- key:string
- Specifies the MAC key as an alphanumeric string (use if the key contain printable characters only). String length must conform to any restrictions of the MAC algorithm.
- hexkey:string
- Specifies the MAC key in hexadecimal form (two hex digits per byte). Key length must conform to any restrictions of the MAC algorithm.
-out
file- The file to output to, or standard output by default.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-prverify
file- Verify the signature using the private key in file. The output is either "Verification OK" or "Verification Failure".
-sign
file- Digitally sign the digest using the private key in file.
-signature
file- The actual signature to verify.
-sigopt
nm:v- Pass options to the signature algorithm during sign or verify operations. The names and values of these options are algorithm-specific.
-verify
file- Verify the signature using the public key in file. The output is either "Verification OK" or "Verification Failure".
- file ...
- File or files to digest. If no files are specified then standard input is used.
DGST NOTES
The digest of choice for all new applications is SHA1. Other digests are, however, still widely used.
If you wish to sign or verify data using the DSA algorithm, the dss1 digest must be used.
A source of random numbers is required for certain signing algorithms, in particular DSA.
The signing and verify options should only be used if a single file is being signed or verified.
DH
Diffie-Hellman Parameter Management. The
dh
command has been replaced by
dhparam
. See
DHPARAM below.
DHPARAM
openssl dhparam |
[-2 | -5 ]
[-C ] [-check ]
[-dsaparam ]
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-text ] [numbits] |
The dhparam
command is used to manipulate
DH parameter files.
The options are as follows:
-2
,-5
- The generator to use, either 2 or 5. 2 is the default. If present, the input file is ignored and parameters are generated instead.
-C
- This option converts the parameters into C code. The parameters can then
be loaded by calling the
get_dh
numbits()
function. -check
- Check the DH parameters.
-dsaparam
- If this option is used, DSA rather than DH parameters are read or created;
they are converted to DH format. Otherwise, "strong" primes
(such that (p-1)/2 is also prime) will be used for DH parameter
generation.
DH parameter generation with the
-dsaparam
option is much faster, and the recommended exponent length is shorter, which makes DH key exchange more efficient. Beware that with such DSA-style DH parameters, a fresh DH key should be created for each use to avoid small-subgroup attacks that may be possible otherwise. -in
file- This specifies the input file to read parameters from, or standard input if this option is not specified.
-inform
DER | PEM- This specifies the input format. The argument DER uses an ASN1 DER-encoded form compatible with the PKCS#3 DHparameter structure. The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines.
-noout
- This option inhibits the output of the encoded version of the parameters.
- numbits
- This argument specifies that a parameter set should be generated of size numbits. It must be the last option. If not present, a value of 2048 is used. If this value is present, the input file is ignored and parameters are generated instead.
-out
file- This specifies the output file to write parameters to. Standard output is used if this option is not present. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -text
- This option prints out the DH parameters in human readable form.
DHPARAM WARNINGS
The program dhparam
combines the
functionality of the programs dh
and
gendh
in previous versions of
OpenSSL
and SSLeay
. The
dh
and gendh
programs are
retained for now, but may have different purposes in future versions of
OpenSSL
.
DHPARAM NOTES
PEM format DH parameters use the header and footer lines:
-----BEGIN DH PARAMETERS----- -----END DH PARAMETERS-----
OpenSSL
currently only supports the older
PKCS#3 DH, not the newer X9.42 DH.
This program manipulates DH parameters not keys.
DHPARAM BUGS
There should be a way to generate and manipulate DH keys.
DHPARAM HISTORY
The dhparam
command was added in
OpenSSL
0.9.5. The -dsaparam
option was added in OpenSSL
0.9.6.
DSA
openssl dsa |
[-aes128
| -aes192 | -aes256 | -des
| -des3 ]
[-in file]
[-inform DER | PEM]
[-modulus ] [-noout ]
[-out file]
[-outform DER | PEM]
[-passin arg]
[-passout arg]
[-pubin ] [-pubout ]
[-text ] |
The dsa
command processes DSA keys. They
can be converted between various forms and their components printed out.
Note: This command uses the traditional
SSLeay
compatible format for private key encryption:
newer applications should use the more secure PKCS#8 format using the
pkcs8
command.
The options are as follows:
-aes128
|-aes192
|-aes256
|-des
|-des3
- These options encrypt the private key with the AES, DES, or the triple DES
ciphers, respectively, before outputting it. A pass phrase is prompted
for. If none of these options is specified, the key is written in plain
text. This means that using the
dsa
utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use to add or change the pass phrase. These options can only be used with PEM format output files. -in
file- This specifies the input file to read a key from, or standard input if this option is not specified. If the key is encrypted, a pass phrase will be prompted for.
-inform
DER | PEM- This specifies the input format. The DER argument
with a private key uses an ASN1 DER-encoded form of an ASN.1 SEQUENCE
consisting of the values of version (currently zero), P, Q, G, and the
public and private key components, respectively, as ASN.1 INTEGERs. When
used with a public key it uses a SubjectPublicKeyInfo
structure: it is an error if the key is not DSA.
The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines. In the case of a private key, PKCS#8 format is also accepted.
-modulus
- This option prints out the value of the public key component of the key.
-noout
- This option prevents output of the encoded version of the key.
-out
file- This specifies the output file to write a key to, or standard output if not specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubin
- By default, a private key is read from the input file. With this option a public key is read instead.
-pubout
- By default, a private key is output. With this option a public key will be output instead. This option is automatically set if the input is a public key.
-text
- Prints out the public/private key components and parameters.
DSA NOTES
The PEM private key format uses the header and footer lines:
-----BEGIN DSA PRIVATE KEY----- -----END DSA PRIVATE KEY-----
The PEM public key format uses the header and footer lines:
-----BEGIN PUBLIC KEY----- -----END PUBLIC KEY-----
DSA EXAMPLES
To remove the pass phrase on a DSA private key:
$ openssl dsa -in key.pem -out
keyout.pem
To encrypt a private key using triple DES:
$ openssl dsa -in key.pem -des3 -out
keyout.pem
To convert a private key from PEM to DER format:
$ openssl dsa -in key.pem -outform
DER -out keyout.der
To print out the components of a private key to standard output:
$ openssl dsa -in key.pem -text
-noout
To just output the public part of a private key:
$ openssl dsa -in key.pem -pubout
-out pubkey.pem
DSAPARAM
openssl dsaparam |
[-C ] [-genkey ]
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-text ] [numbits] |
The dsaparam
command is used to manipulate
or generate DSA parameter files.
The options are as follows:
-C
- This option converts the parameters into C code. The parameters can then
be loaded by calling the
get_dsa
XXX()
function. -genkey
- This option will generate a DSA either using the specified or generated parameters.
-in
file- This specifies the input file to read parameters from, or standard input if this option is not specified. If the numbits parameter is included, then this option will be ignored.
-inform
DER | PEM- This specifies the input format. The DER argument uses an ASN1 DER-encoded form compatible with RFC 2459 (PKIX) DSS-Parms that is a SEQUENCE consisting of p, q and g, respectively. The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines.
-noout
- This option inhibits the output of the encoded version of the parameters.
- numbits
- This option specifies that a parameter set should be generated of size numbits. If this option is included, the input file (if any) is ignored.
-out
file- This specifies the output file to write parameters to. Standard output is used if this option is not present. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -text
- This option prints out the DSA parameters in human readable form.
DSAPARAM NOTES
PEM format DSA parameters use the header and footer lines:
-----BEGIN DSA PARAMETERS----- -----END DSA PARAMETERS-----
DSA parameter generation is a slow process and as a result the same set of DSA parameters is often used to generate several distinct keys.
EC
openssl ec |
[-conv_form arg]
[-des ] [-des3 ]
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-param_enc arg]
[-param_out ]
[-passin arg]
[-passout arg]
[-pubin ] [-pubout ]
[-text ] |
The ec
command processes EC keys. They can
be converted between various forms and their components printed out. Note:
OpenSSL
uses the private key format specified in
“SEC 1: Elliptic Curve Cryptography”
(http://www.secg.org/). To
convert an OpenSSL
EC private key into the PKCS#8
private key format use the pkcs8
command.
The options are as follows:
-conv_form
arg- This specifies how the points on the elliptic curve are converted into
octet strings. Possible values are:
compressed
(the default value),uncompressed
, andhybrid
. For more information regarding the point conversion forms please read the X9.62 standard. Note: Due to patent issues thecompressed
option is disabled by default for binary curves and can be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at compile time. -des
|-des3
- These options encrypt the private key with the DES, triple DES, or any
other cipher supported by
OpenSSL
before outputting it. A pass phrase is prompted for. If none of these options is specified the key is written in plain text. This means that using theec
utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use to add or change the pass phrase. These options can only be used with PEM format output files. -in
file- This specifies the input filename to read a key from, or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for.
-inform
DER | PEM- This specifies the input format. DER with a private key uses an ASN.1 DER-encoded SEC1 private key. When used with a public key it uses the SubjectPublicKeyInfo structure as specified in RFC 3280. PEM is the default format: it consists of the DER format base64 encoded with additional header and footer lines. In the case of a private key PKCS#8 format is also accepted.
-noout
- Prevents output of the encoded version of the key.
-out
file- Specifies the output filename to write a key to, or standard output if none is specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format. The options have the same meaning as the
-inform
option. -param_enc
arg- This specifies how the elliptic curve parameters are encoded. Possible
value are:
named_curve
, i.e. the EC parameters are specified by an OID; orexplicit
, where the EC parameters are explicitly given (see RFC 3279 for the definition of the EC parameter structures). The default value isnamed_curve
. Note: theimplicitlyCA
alternative, as specified in RFC 3279, is currently not implemented inOpenSSL
. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubin
- By default a private key is read from the input file; with this option a public key is read instead.
-pubout
- By default a private key is output; with this option a public key is output instead. This option is automatically set if the input is a public key.
-text
- Prints out the public/private key components and parameters.
EC NOTES
The PEM private key format uses the header and footer lines:
-----BEGIN EC PRIVATE KEY----- -----END EC PRIVATE KEY-----
The PEM public key format uses the header and footer lines:
-----BEGIN PUBLIC KEY----- -----END PUBLIC KEY-----
EC EXAMPLES
To encrypt a private key using triple DES:
$ openssl ec -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
$ openssl ec -in key.pem -outform DER -out keyout.der
To print out the components of a private key to standard output:
$ openssl ec -in key.pem -text -noout
To just output the public part of a private key:
$ openssl ec -in key.pem -pubout -out pubkey.pem
To change the parameter encoding to
explicit
:
$ openssl ec -in key.pem -param_enc explicit -out keyout.pem
To change the point conversion form to
compressed
:
$ openssl ec -in key.pem -conv_form compressed -out keyout.pem
EC HISTORY
The ec
command was first introduced in
OpenSSL
0.9.8.
EC AUTHORS
Nils Larsch.
ECPARAM
openssl ecparam |
[-C ] [-check ]
[-conv_form arg]
[-genkey ]
[-in file]
[-inform DER | PEM]
[-list_curves ]
[-name arg]
[-no_seed ] [-noout ]
[-out file]
[-outform DER | PEM]
[-param_enc arg]
[-text ] |
This command is used to manipulate or generate EC parameter files.
The options are as follows:
-C
- Convert the EC parameters into C code. The parameters can then be loaded
by calling the
get_ec_group_XXX
() function. -check
- Validate the elliptic curve parameters.
-conv_form
arg- Specify how the points on the elliptic curve are converted into octet
strings. Possible values are:
compressed
(the default value),uncompressed
, andhybrid
. For more information regarding the point conversion forms please read the X9.62 standard. Note: Due to patent issues thecompressed
option is disabled by default for binary curves and can be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at compile time. -genkey
- Generate an EC private key using the specified parameters.
-in
file- Specify the input filename to read parameters from or standard input if this option is not specified.
-inform
DER | PEM- Specify the input format. DER uses an ASN.1 DER-encoded form compatible with RFC 3279 EcpkParameters. PEM is the default format: it consists of the DER format base64 encoded with additional header and footer lines.
-list_curves
- Print out a list of all currently implemented EC parameter names and exit.
-name
arg- Use the EC parameters with the specified 'short' name. Use
-list_curves
to get a list of all currently implemented EC parameters. -no_seed
- Inhibit that the 'seed' for the parameter generation is included in the ECParameters structure (see RFC 3279).
-noout
- Inhibit the output of the encoded version of the parameters.
-out
file- Specify the output filename parameters are written to. Standard output is used if this option is not present. The output filename should not be the same as the input filename.
-outform
DER | PEM- Specify the output format; the parameters have the same meaning as the
-inform
option. -param_enc
arg- This specifies how the elliptic curve parameters are encoded. Possible
value are:
named_curve
, i.e. the EC parameters are specified by an OID, orexplicit
, where the EC parameters are explicitly given (see RFC 3279 for the definition of the EC parameter structures). The default value isnamed_curve
. Note: theimplicitlyCA
alternative, as specified in RFC 3279, is currently not implemented inOpenSSL
. -text
- Print out the EC parameters in human readable form.
ECPARAM NOTES
PEM format EC parameters use the header and footer lines:
-----BEGIN EC PARAMETERS----- -----END EC PARAMETERS-----
OpenSSL
is currently not able to generate
new groups and therefore ecparam
can only create EC
parameters from known (named) curves.
ECPARAM EXAMPLES
To create EC parameters with the group 'prime192v1':
$ openssl ecparam -out ec_param.pem -name prime192v1
To create EC parameters with explicit parameters:
$ openssl ecparam -out ec_param.pem -name prime192v1 \ -param_enc explicit
To validate given EC parameters:
$ openssl ecparam -in ec_param.pem -check
To create EC parameters and a private key:
$ openssl ecparam -out ec_key.pem -name prime192v1 -genkey
To change the point encoding to 'compressed':
$ openssl ecparam -in ec_in.pem -out ec_out.pem \ -conv_form compressed
To print out the EC parameters to standard output:
$ openssl ecparam -in ec_param.pem -noout -text
ECPARAM HISTORY
The ecparam
command was first introduced
in OpenSSL
0.9.8.
ECPARAM AUTHORS
Nils Larsch.
ENC
openssl enc |
-ciphername [-AadePp ]
[-base64 ]
[-bufsize number]
[-debug ]
[-in file]
[-iv IV]
[-K key]
[-k password]
[-kfile file]
[-md digest]
[-none ] [-nopad ]
[-nosalt ]
[-out file]
[-pass arg]
[-S salt]
[-salt ] |
The symmetric cipher commands allow data to be encrypted or decrypted using various block and stream ciphers using keys based on passwords or explicitly provided. Base64 encoding or decoding can also be performed either by itself or in addition to the encryption or decryption.
The options are as follows:
-A
- If the
-a
option is set, then base64 process the data on one line. -a
,-base64
- Base64 process the data. This means that if encryption is taking place, the data is base64-encoded after encryption. If decryption is set, the input data is base64 decoded before being decrypted.
-bufsize
number- Set the buffer size for I/O.
-d
- Decrypt the input data.
-debug
- Debug the BIOs used for I/O.
-e
- Encrypt the input data: this is the default.
-in
file- The input file; standard input by default.
-iv
IV- The actual IV (initialisation vector) to use: this
must be represented as a string comprised only of hex digits. When only
the key is specified using the
-K
option, the IV must explicitly be defined. When a password is being specified using one of the other options, the IV is generated from this password. -K
key- The actual key to use: this must be represented as a
string comprised only of hex digits. If only the key is specified, the
IV must be additionally specified using the
-iv
option. When both a key and a password are specified, the key given with the-K
option will be used and the IV generated from the password will be taken. It probably does not make much sense to specify both key and password. -k
password- The password to derive the key from. This is for
compatibility with previous versions of
OpenSSL
. Superseded by the-pass
option. -kfile
file- Read the password to derive the key from the first line of
file. This is for compatibility with previous
versions of
OpenSSL
. Superseded by the-pass
option. -md
digest- Use digest to create a key from a pass phrase. digest may be one of “md5” or “sha1”.
-none
- Use NULL cipher (no encryption or decryption of input).
-nopad
- Disable standard block padding.
-nosalt
- Don't use a salt in the key derivation routines.
This option should NEVER be used unless compatibility
with previous versions of
OpenSSL
orSSLeay
is required. -out
file- The output file, standard output by default.
-P
- Print out the salt, key, and IV used, then immediately exit; don't do any encryption or decryption.
-p
- Print out the salt, key, and IV used.
-pass
arg- The password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-S
salt- The actual salt to use: this must be represented as a string comprised only of hex digits.
-salt
- Use a salt in the key derivation routines. This is the default.
ENC NOTES
The program can be called either as openssl
ciphername
or openssl enc -ciphername
.
A password will be prompted for to derive the key and IV if necessary.
The -nosalt
option should
NEVER be used unless compatibility with previous versions
of OpenSSL
or SSLeay
is
required.
With the -nosalt
option it is possible to
perform efficient dictionary attacks on the password and to attack stream
cipher encrypted data. The reason for this is that without the salt the same
password always generates the same encryption key. When the salt is being
used the first eight bytes of the encrypted data are reserved for the salt:
it is generated at random when encrypting a file and read from the encrypted
file when it is decrypted.
Some of the ciphers do not have large keys and others have security implications if not used correctly. A beginner is advised to just use a strong block cipher in CBC mode such as bf or des3.
All the block ciphers normally use PKCS#5 padding also known as standard block padding: this allows a rudimentary integrity or password check to be performed. However, since the chance of random data passing the test is better than 1 in 256, it isn't a very good test.
If padding is disabled, the input data must be a multiple of the cipher block length.
All RC2 ciphers have the same key and effective key length.
Blowfish and RC5 algorithms use a 128-bit key.
ENC SUPPORTED CIPHERS
aes-[128|192|256]-cbc 128/192/256 bit AES in CBC mode aes-[128|192|256] Alias for aes-[128|192|256]-cbc aes-[128|192|256]-cfb 128/192/256 bit AES in 128 bit CFB mode aes-[128|192|256]-cfb1 128/192/256 bit AES in 1 bit CFB mode aes-[128|192|256]-cfb8 128/192/256 bit AES in 8 bit CFB mode aes-[128|192|256]-ecb 128/192/256 bit AES in ECB mode aes-[128|192|256]-ofb 128/192/256 bit AES in OFB mode base64 Base 64 bf Alias for bf-cbc bf-cbc Blowfish in CBC mode bf-cfb Blowfish in CFB mode bf-ecb Blowfish in ECB mode bf-ofb Blowfish in OFB mode cast Alias for cast-cbc cast-cbc CAST in CBC mode cast5-cbc CAST5 in CBC mode cast5-cfb CAST5 in CFB mode cast5-ecb CAST5 in ECB mode cast5-ofb CAST5 in OFB mode des Alias for des-cbc des-cbc DES in CBC mode des-cfb DES in CBC mode des-ecb DES in ECB mode des-ofb DES in OFB mode des-ede Two key triple DES EDE in ECB mode des-ede-cbc Two key triple DES EDE in CBC mode des-ede-cfb Two key triple DES EDE in CFB mode des-ede-ofb Two key triple DES EDE in OFB mode des3 Alias for des-ede3-cbc des-ede3 Three key triple DES EDE in ECB mode des-ede3-cbc Three key triple DES EDE in CBC mode des-ede3-cfb Three key triple DES EDE CFB mode des-ede3-ofb Three key triple DES EDE in OFB mode desx DESX algorithm rc2 Alias for rc2-cbc rc2-cbc 128-bit RC2 in CBC mode rc2-cfb 128-bit RC2 in CFB mode rc2-ecb 128-bit RC2 in ECB mode rc2-ofb 128-bit RC2 in OFB mode rc2-64-cbc 64-bit RC2 in CBC mode rc2-40-cbc 40-bit RC2 in CBC mode rc4 128-bit RC4 rc4-40 40-bit RC4
ENC EXAMPLES
Just base64 encode a binary file:
$ openssl base64 -in file.bin -out
file.b64
Decode the same file:
$ openssl base64 -d -in file.b64 -out
file.bin
Encrypt a file using triple DES in CBC mode using a prompted password:
$ openssl des3 -salt -in file.txt
-out file.des3
Decrypt a file using a supplied password:
$ openssl des3 -d -in file.des3 -out
file.txt -k mypassword
Encrypt a file then base64 encode it (so it can be sent via mail for example) using Blowfish in CBC mode:
$ openssl bf -a -salt -in file.txt
-out file.bf
Base64 decode a file then decrypt it:
$ openssl bf -d -a -in file.bf -out
file.txt
ENC BUGS
The -A
option when used with large files
doesn't work properly.
There should be an option to allow an iteration count to be included.
The enc
program only supports a fixed
number of algorithms with certain parameters. Therefore it is not possible
to use RC2 with a 76-bit key or RC4 with an 84-bit key with this
program.
ERRSTR
openssl errstr
[-stats
] errno ...
The errstr
command performs error number
to error string conversion, generating a human-readable string representing
the error code errno. The string is obtained through
the
ERR_error_string_n(3) function and has the following
format:
error:[error code]:[library
name]:[function name]:[reason string]
[error code] is an 8-digit hexadecimal number. The remaining fields [library name], [function name], and [reason string] are all ASCII text.
The options are as follows:
-stats
- Print debugging statistics about various aspects of the hash table.
ERRSTR EXAMPLES
The following error code:
27594:error:2006D080:lib(32):func(109):reason(128):bss_file.c:107:
...can be displayed with:
$ openssl errstr
2006D080
...to produce the error message:
error:2006D080:BIO
routines:BIO_new_file:no such file
GENDH
Generation of Diffie-Hellman Parameters. Replaced by
dhparam
. See
DHPARAM above.
GENDSA
openssl gendsa |
[-aes128
| -aes192 | -aes256 | -des
| -des3 ]
[-out file]
[paramfile] |
The gendsa
command generates a DSA private
key from a DSA parameter file (which will typically be generated by the
openssl dsaparam
command).
The options are as follows:
-aes128
|-aes192
|-aes256
|-des
|-des3
- These options encrypt the private key with the AES, DES, or the triple DES ciphers, respectively, before outputting it. A pass phrase is prompted for. If none of these options are specified, no encryption is used.
-out
file- The output file. If this argument is not specified, standard output is used.
- paramfile
- This option specifies the DSA parameter file to use. The parameters in
this file determine the size of the private key. DSA parameters can be
generated and examined using the
openssl dsaparam
command.
GENDSA NOTES
DSA key generation is little more than random number generation so it is much quicker than RSA key generation, for example.
GENPKEY
openssl genpkey |
[-algorithm alg]
[cipher] [-genparam ]
[-out file]
[-outform DER | PEM]
[-paramfile file]
[-pass arg]
[-pkeyopt opt:value]
[-text ] |
The genpkey
command generates private
keys. The use of this program is encouraged over the algorithm specific
utilities because additional algorithm options can be used.
The options are as follows:
-algorithm
alg- The public key algorithm to use, such as RSA, DSA, or DH. If used this
option must precede any
-pkeyopt
options. The options-paramfile
and-algorithm
are mutually exclusive. - cipher
- Encrypt the private key with the supplied cipher. Any algorithm name
accepted by
EVP_get_cipherbyname
() is acceptable, such asdes3
. -genparam
- Generate a set of parameters instead of a private key. If used this option
must precede any
-algorithm
,-paramfile
, or-pkeyopt
options. -out
file- The output filename. If this argument is not specified then standard output is used.
-outform
DER | PEM- This specifies the output format, DER or PEM.
-paramfile
file- Some public key algorithms generate a private key based on a set of
parameters. They can be supplied using this option. If this option is used
the public key algorithm used is determined by the parameters. If used
this option must precede any
-pkeyopt
options. The options-paramfile
and-algorithm
are mutually exclusive. -pass
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pkeyopt
opt:value- Set the public key algorithm option opt to value. The precise set of options supported depends on the public key algorithm used and its implementation. See GENPKEY KEY GENERATION OPTIONS below for more details.
-text
- Print an (unencrypted) text representation of private and public keys and parameters along with the DER or PEM structure.
GENPKEY KEY GENERATION OPTIONS
The options supported by each algorithm and indeed each
implementation of an algorithm can vary. The options for the
OpenSSL
implementations are detailed below.
- rsa_keygen_bits:numbits
- (RSA) The number of bits in the generated key. If not specified 2048 is used.
- rsa_keygen_pubexp:value
- (RSA) The RSA public exponent value. This can be a large decimal or hexadecimal value if preceded by 0x. The default value is 65537.
- dsa_paramgen_bits:numbits
- (DSA) The number of bits in the generated parameters. If not specified 1024 is used.
- dh_paramgen_prime_len:numbits
- (DH) The number of bits in the prime parameter p.
- dh_paramgen_generator:value
- (DH) The value to use for the generator g.
- ec_paramgen_curve:curve
- (EC) The EC curve to use.
GENPKEY EXAMPLES
Generate an RSA private key using default parameters:
$ openssl genpkey -algorithm RSA -out key.pem
Encrypt and output a private key using 128-bit AES and the passphrase "hello":
$ openssl genpkey -algorithm RSA -out key.pem \ -aes-128-cbc -pass pass:hello
Generate a 2048-bit RSA key using 3 as the public exponent:
$ openssl genpkey -algorithm RSA -out key.pem \ -pkeyopt rsa_keygen_bits:2048 -pkeyopt rsa_keygen_pubexp:3
Generate 1024-bit DSA parameters:
$ openssl genpkey -genparam -algorithm DSA \ -out dsap.pem -pkeyopt dsa_paramgen_bits:1024
Generate a DSA key from parameters:
$ openssl genpkey -paramfile dsap.pem -out dsakey.pem
Generate 1024-bit DH parameters:
$ openssl genpkey -genparam -algorithm DH \ -out dhp.pem -pkeyopt dh_paramgen_prime_len:1024
Generate a DH key from parameters:
$ openssl genpkey -paramfile dhp.pem -out dhkey.pem
GENRSA
openssl genrsa |
[-3 | -f4 ]
[-aes128
| -aes192 | -aes256 | -des
| -des3 ]
[-out file]
[-passout arg]
[numbits] |
The genrsa
command generates an RSA
private key.
The options are as follows:
-3
|-f4
- The public exponent to use, either 3 or 65537. The default is 65537.
-aes128
|-aes192
|-aes256
|-des
|-des3
- These options encrypt the private key with the AES, DES, or the triple DES
ciphers, respectively, before outputting it. If none of these options are
specified, no encryption is used. If encryption is used, a pass phrase is
prompted for, if it is not supplied via the
-passout
option. -out
file- The output file. If this argument is not specified, standard output is used.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
- numbits
- The size of the private key to generate in bits. This must be the last option specified. The default is 2048.
GENRSA NOTES
RSA private key generation essentially involves the generation of two prime numbers. When generating a private key, various symbols will be output to indicate the progress of the generation. A ‘.’ represents each number which has passed an initial sieve test; ‘+’ means a number has passed a single round of the Miller-Rabin primality test. A newline means that the number has passed all the prime tests (the actual number depends on the key size).
Because key generation is a random process, the time taken to generate a key may vary somewhat.
GENRSA BUGS
A quirk of the prime generation algorithm is that it cannot generate small primes. Therefore the number of bits should not be less that 64. For typical private keys this will not matter because for security reasons they will be much larger (typically 2048 bits).
NSEQ
openssl nseq
[-in
file] [-out
file] [-toseq
]
The nseq
command takes a file containing a
Netscape certificate sequence and prints out the certificates contained in
it or takes a file of certificates and converts it into a Netscape
certificate sequence.
The options are as follows:
-in
file- This specifies the input file to read, or standard input if this option is not specified.
-out
file- Specifies the output file, or standard output by default.
-toseq
- Normally, a Netscape certificate sequence will be input and the output is
the certificates contained in it. With the
-toseq
option the situation is reversed: a Netscape certificate sequence is created from a file of certificates.
NSEQ EXAMPLES
Output the certificates in a Netscape certificate sequence:
$ openssl nseq -in nseq.pem -out certs.pem
Create a Netscape certificate sequence:
$ openssl nseq -in certs.pem -toseq -out nseq.pem
NSEQ NOTES
The PEM-encoded form uses the same headers and footers as a certificate:
-----BEGIN CERTIFICATE----- -----END CERTIFICATE-----
A Netscape certificate sequence is a Netscape specific form that can be sent to browsers as an alternative to the standard PKCS#7 format when several certificates are sent to the browser: for example during certificate enrollment. It is used by the Netscape certificate server, for example.
NSEQ BUGS
This program needs a few more options, like allowing DER or PEM input and output files and allowing multiple certificate files to be used.
OCSP
openssl ocsp |
[-CA file]
[-CAfile file]
[-CApath directory]
[-cert file]
[-dgst alg]
[-host
hostname:port]
[-index indexfile]
[-issuer file]
[-ndays days]
[-nmin minutes]
[-no_cert_checks ]
[-no_cert_verify ]
[-no_certs ] [-no_chain ]
[-no_intern ] [-no_nonce ]
[-no_signature_verify ]
[-nonce ] [-noverify ]
[-nrequest number]
[-out file]
[-path path]
[-port portnum]
[-req_text ]
[-reqin file]
[-reqout file]
[-resp_key_id ]
[-resp_no_certs ]
[-resp_text ]
[-respin file]
[-respout file]
[-rkey file]
[-rother file]
[-rsigner file]
[-serial number]
[-sign_other file]
[-signer file]
[-signkey file]
[-status_age age]
[-text ] [-trust_other ]
[-url responder_url]
[-VAfile file]
[-validity_period nsec]
[-verify_other file] |
The Online Certificate Status Protocol (OCSP) enables applications to determine the (revocation) state of an identified certificate (RFC 2560).
The ocsp
command performs many common OCSP
tasks. It can be used to print out requests and responses, create requests
and send queries to an OCSP responder, and behave like a mini OCSP server
itself.
The options are as follows:
-CAfile
file,-CApath
directory- file or path containing trusted CA certificates. These are used to verify the signature on the OCSP response.
-cert
file- Add the certificate file to the request. The issuer
certificate is taken from the previous
-issuer
option, or an error occurs if no issuer certificate is specified. -dgst
alg- Sets the digest algorithm to use for certificate identification in the OCSP request. By default SHA-1 is used.
-host
hostname:port,-path
path- If the
-host
option is present, then the OCSP request is sent to the host hostname on port port.-path
specifies the HTTP path name to use, or ‘/’ by default. -issuer
file- This specifies the current issuer certificate. This option can be used
multiple times. The certificate specified in file
must be in PEM format. This option must come before any
-cert
options. -no_cert_checks
- Don't perform any additional checks on the OCSP response signer's certificate. That is, do not make any checks to see if the signer's certificate is authorised to provide the necessary status information: as a result this option should only be used for testing purposes.
-no_cert_verify
- Don't verify the OCSP response signer's certificate at all. Since this option allows the OCSP response to be signed by any certificate, it should only be used for testing purposes.
-no_certs
- Don't include any certificates in signed request.
-no_chain
- Do not use certificates in the response as additional untrusted CA certificates.
-no_intern
- Ignore certificates contained in the OCSP response when searching for the
signer's certificate. With this option, the signer's certificate must be
specified with either the
-verify_other
or-VAfile
options. -no_signature_verify
- Don't check the signature on the OCSP response. Since this option tolerates invalid signatures on OCSP responses, it will normally only be used for testing purposes.
-nonce
,-no_nonce
- Add an OCSP nonce extension to a request or disable an
OCSP nonce addition. Normally, if an OCSP request is
input using the
-respin
option no nonce is added: using the-nonce
option will force addition of a nonce. If an OCSP request is being created (using the-cert
and-serial
options) a nonce is automatically added; specifying-no_nonce
overrides this. -noverify
- Don't attempt to verify the OCSP response signature or the nonce values. This option will normally only be used for debugging since it disables all verification of the responder's certificate.
-out
file- Specify output file; default is standard output.
-req_text
,-resp_text
,-text
- Print out the text form of the OCSP request, response, or both, respectively.
-reqin
file,-respin
file- Read an OCSP request or response file from file.
These options are ignored if an OCSP request or response creation is
implied by other options (for example with the
-serial
,-cert
, and-host
options). -reqout
file,-respout
file- Write out the DER-encoded certificate request or response to file.
-serial
num- Same as the
-cert
option except the certificate with serial number num is added to the request. The serial number is interpreted as a decimal integer unless preceded by ‘0x’. Negative integers can also be specified by preceding the value with a ‘-’ sign. -sign_other
file- Additional certificates to include in the signed request.
-signer
file,-signkey
file- Sign the OCSP request using the certificate specified in the
-signer
option and the private key specified by the-signkey
option. If the-signkey
option is not present, then the private key is read from the same file as the certificate. If neither option is specified, the OCSP request is not signed. -trust_other
- The certificates specified by the
-verify_other
option should be explicitly trusted and no additional checks will be performed on them. This is useful when the complete responder certificate chain is not available or trusting a root CA is not appropriate. -url
responder_url- Specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can be specified.
-VAfile
file- file containing explicitly trusted responder
certificates. Equivalent to the
-verify_other
and-trust_other
options. -validity_period
nsec,-status_age
age- These options specify the range of times, in seconds, which will be
tolerated in an OCSP response. Each certificate status response includes a
notBefore time and an optional
notAfter time. The current time should fall between
these two values, but the interval between the two times may be only a few
seconds. In practice the OCSP responder and clients' clocks may not be
precisely synchronised and so such a check may fail. To avoid this the
-validity_period
option can be used to specify an acceptable error range in seconds, the default value is 5 minutes.If the notAfter time is omitted from a response, then this means that new status information is immediately available. In this case the age of the notBefore field is checked to see it is not older than age seconds old. By default, this additional check is not performed.
-verify_other
file- file containing additional certificates to search when attempting to locate the OCSP response signing certificate. Some responders omit the actual signer's certificate from the response; this option can be used to supply the necessary certificate in such cases.
OCSP SERVER OPTIONS
-CA
file- CA certificate corresponding to the revocation information in indexfile.
-index
indexfile- indexfile is a text index file in
ca
format containing certificate revocation information.If the
-index
option is specified, theocsp
utility is in responder mode, otherwise it is in client mode. The request(s) the responder processes can be either specified on the command line (using the-issuer
and-serial
options), supplied in a file (using the-respin
option) or via external OCSP clients (if port or url is specified).If the
-index
option is present, then the-CA
and-rsigner
options must also be present. -nmin
minutes,-ndays
days- Number of minutes or days when fresh revocation information is available: used in the nextUpdate field. If neither option is present, the nextUpdate field is omitted, meaning fresh revocation information is immediately available.
-nrequest
number- The OCSP server will exit after receiving number requests, default unlimited.
-port
portnum- Port to listen for OCSP requests on. The port may also be specified using
the
-url
option. -resp_key_id
- Identify the signer certificate using the key ID; default is to use the subject name.
-resp_no_certs
- Don't include any certificates in the OCSP response.
-rkey
file- The private key to sign OCSP responses with; if not present, the file
specified in the
-rsigner
option is used. -rother
file- Additional certificates to include in the OCSP response.
-rsigner
file- The certificate to sign OCSP responses with.
OCSP RESPONSE VERIFICATION
OCSP Response follows the rules specified in RFC 2560.
Initially the OCSP responder certificate is located and the signature on the OCSP request checked using the responder certificate's public key.
Then a normal certificate verify is performed on the OCSP
responder certificate building up a certificate chain in the process. The
locations of the trusted certificates used to build the chain can be
specified by the -CAfile
and
-CApath
options or they will be looked for in the
standard OpenSSL
certificates directory.
If the initial verify fails, the OCSP verify process halts with an error.
Otherwise the issuing CA certificate in the request is compared to the OCSP responder certificate: if there is a match then the OCSP verify succeeds.
Otherwise the OCSP responder certificate's CA is checked against the issuing CA certificate in the request. If there is a match and the OCSPSigning extended key usage is present in the OCSP responder certificate, then the OCSP verify succeeds.
Otherwise the root CA of the OCSP responder's CA is checked to see if it is trusted for OCSP signing. If it is, the OCSP verify succeeds.
If none of these checks is successful, the OCSP verify fails.
What this effectively means is that if the OCSP responder certificate is authorised directly by the CA it is issuing revocation information about (and it is correctly configured), then verification will succeed.
If the OCSP responder is a global responder which can give details about multiple CAs and has its own separate certificate chain, then its root CA can be trusted for OCSP signing. For example:
$ openssl x509 -in ocspCA.pem -addtrust OCSPSigning \ -out trustedCA.pem
Alternatively, the responder certificate itself can be explicitly
trusted with the -VAfile
option.
OCSP NOTES
As noted, most of the verify options are for testing or debugging
purposes. Normally, only the -CApath
,
-CAfile
and (if the responder is a `global VA')
-VAfile
options need to be used.
The OCSP server is only useful for test and demonstration purposes: it is not really usable as a full OCSP responder. It contains only a very simple HTTP request handling and can only handle the POST form of OCSP queries. It also handles requests serially, meaning it cannot respond to new requests until it has processed the current one. The text index file format of revocation is also inefficient for large quantities of revocation data.
It is possible to run the ocsp
application
in responder mode via a CGI script using the
-respin
and -respout
options.
OCSP EXAMPLES
Create an OCSP request and write it to a file:
$ openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \ -reqout req.der
Send a query to an OCSP responder with URL http://ocsp.myhost.com/, save the response to a file and print it out in text form:
$ openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \ -url http://ocsp.myhost.com/ -resp_text -respout resp.der
Read in an OCSP response and print out in text form:
$ openssl ocsp -respin resp.der
-text
OCSP server on port 8888 using a standard
ca
configuration, and a separate responder
certificate. All requests and responses are printed to a file:
$ openssl ocsp -index demoCA/index.txt -port 8888 -rsigner \ rcert.pem -CA demoCA/cacert.pem -text -out log.txt
As above, but exit after processing one request:
$ openssl ocsp -index demoCA/index.txt -port 8888 -rsigner \ rcert.pem -CA demoCA/cacert.pem -nrequest 1
Query status information using internally generated request:
$ openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA \ demoCA/cacert.pem -issuer demoCA/cacert.pem -serial 1
Query status information using request read from a file and write the response to a second file:
$ openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA \ demoCA/cacert.pem -reqin req.der -respout resp.der
PASSWD
openssl passwd |
[-1 | -apr1 |
-crypt ] [-in
file] [-noverify ]
[-quiet ] [-reverse ]
[-salt string]
[-stdin ] [-table ]
[password] |
The passwd
command computes the hash of a
password typed at run-time or the hash of each password in a list. The
password list is taken from the named file for option
-in
, from stdin for option
-stdin
, or from the command line, or from the
terminal otherwise. The UNIX standard algorithm
crypt and the MD5-based BSD
password algorithm 1 and its Apache variant
apr1 are available.
The options are as follows:
-1
- Use the MD5 based BSD password algorithm 1.
-apr1
- Use the apr1 algorithm (Apache variant of the) BSD algorithm.
-crypt
- Use the crypt algorithm (default).
-in
file- Read passwords from file.
-noverify
- Don't verify when reading a password from the terminal.
-quiet
- Don't output warnings when passwords given on the command line are truncated.
-reverse
- Switch table columns. This only makes sense in conjunction with the
-table
option. -salt
string- Use the specified salt. When reading a password from
the terminal, this implies
-noverify
. -stdin
- Read passwords from stdin.
-table
- In the output list, prepend the cleartext password and a TAB character to each password hash.
PASSWD EXAMPLES
$ openssl passwd -crypt -salt xx
password
prints "xxj31ZMTZzkVA".
$ openssl passwd -1 -salt xxxxxxxx
password
$ openssl passwd -apr1 -salt xxxxxxxx
password
PKCS7
openssl pkcs7 |
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-print_certs ]
[-text ] |
The pkcs7
command processes PKCS#7 files
in DER or PEM format.
The options are as follows:
-in
file- This specifies the input file to read from, or standard input if this option is not specified.
-inform
DER | PEM- This specifies the input format. DER format is a DER-encoded PKCS#7 v1.5 structure. PEM (the default) is a base64-encoded version of the DER form with header and footer lines.
-noout
- Don't output the encoded version of the PKCS#7 structure (or certificates
if
-print_certs
is set). -out
file- Specifies the output file to write to, or standard output by default.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -print_certs
- Prints out any certificates or CRLs contained in the file. They are preceded by their subject and issuer names in a one-line format.
-text
- Prints out certificate details in full rather than just subject and issuer names.
PKCS7 EXAMPLES
Convert a PKCS#7 file from PEM to DER:
$ openssl pkcs7 -in file.pem -outform
DER -out file.der
Output all certificates in a file:
$ openssl pkcs7 -in file.pem
-print_certs -out certs.pem
PKCS7 NOTES
The PEM PKCS#7 format uses the header and footer lines:
-----BEGIN PKCS7----- -----END PKCS7-----
For compatibility with some CAs it will also accept:
-----BEGIN CERTIFICATE----- -----END CERTIFICATE-----
PKCS7 RESTRICTIONS
There is no option to print out all the fields of a PKCS#7 file.
The PKCS#7 routines only understand PKCS#7 v 1.5 as specified in RFC 2315. They cannot currently parse, for example, the new CMS as described in RFC 2630.
PKCS8
openssl pkcs8 |
[-embed ]
[-in file]
[-inform DER | PEM]
[-nocrypt ] [-noiter ]
[-nooct ] [-nsdb ]
[-out file]
[-outform DER | PEM]
[-passin arg]
[-passout arg]
[-topk8 ]
[-v1 alg]
[-v2 alg] |
The pkcs8
command processes private keys
in PKCS#8 format. It can handle both unencrypted PKCS#8 PrivateKeyInfo
format and EncryptedPrivateKeyInfo format with a variety of PKCS#5 (v1.5 and
v2.0) and PKCS#12 algorithms.
The options are as follows:
-embed
- This option generates DSA keys in a broken format. The DSA parameters are embedded inside the PrivateKey structure. In this form the OCTET STRING contains an ASN1 SEQUENCE consisting of two structures: a SEQUENCE containing the parameters and an ASN1 INTEGER containing the private key.
-in
file- This specifies the input file to read a key from, or standard input if this option is not specified. If the key is encrypted, a pass phrase will be prompted for.
-inform
DER | PEM- This specifies the input format. If a PKCS#8 format key is expected on input, then either a DER- or PEM-encoded version of a PKCS#8 key will be expected. Otherwise the DER or PEM format of the traditional format private key is used.
-nocrypt
- PKCS#8 keys generated or input are normally PKCS#8 EncryptedPrivateKeyInfo structures using an appropriate password-based encryption algorithm. With this option, an unencrypted PrivateKeyInfo structure is expected or output. This option does not encrypt private keys at all and should only be used when absolutely necessary. Certain software such as some versions of Java code signing software use unencrypted private keys.
-noiter
- Use an iteration count of 1. See the PKCS12 section below for a detailed explanation of this option.
-nooct
- This option generates RSA private keys in a broken format that some software uses. Specifically the private key should be enclosed in an OCTET STRING, but some software just includes the structure itself without the surrounding OCTET STRING.
-nsdb
- This option generates DSA keys in a broken format compatible with Netscape private key databases. The PrivateKey contains a SEQUENCE consisting of the public and private keys, respectively.
-out
file- This specifies the output file to write a key to, or standard output by default. If any encryption options are set, a pass phrase will be prompted for. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-topk8
- Normally, a PKCS#8 private key is expected on input and a traditional
format private key will be written. With the
-topk8
option the situation is reversed: it reads a traditional format private key and writes a PKCS#8 format key. -v1
alg- This option specifies a PKCS#5 v1.5 or PKCS#12 algorithm to use. A complete list of possible algorithms is included below.
-v2
alg- This option enables the use of PKCS#5 v2.0 algorithms. Normally, PKCS#8
private keys are encrypted with the password-based encryption algorithm
called
pbeWithMD5AndDES-CBC;
this uses 56-bit DES encryption but it was the strongest encryption
algorithm supported in PKCS#5 v1.5. Using the
-v2
option PKCS#5 v2.0 algorithms are used which can use any encryption algorithm such as 168-bit triple DES or 128-bit RC2, however not many implementations support PKCS#5 v2.0 yet. If using private keys withOpenSSL
then this doesn't matter.The alg argument is the encryption algorithm to use; valid values include des, des3, and rc2. It is recommended that des3 is used.
PKCS8 NOTES
The encrypted form of a PEM-encoded PKCS#8 file uses the following headers and footers:
-----BEGIN ENCRYPTED PRIVATE KEY----- -----END ENCRYPTED PRIVATE KEY-----
The unencrypted form uses:
-----BEGIN PRIVATE KEY----- -----END PRIVATE KEY-----
Private keys encrypted using PKCS#5 v2.0 algorithms and high
iteration counts are more secure than those encrypted using the traditional
SSLeay
compatible formats. So if additional security
is considered important, the keys should be converted.
The default encryption is only 56 bits because this is the encryption that most current implementations of PKCS#8 support.
Some software may use PKCS#12 password-based encryption algorithms with PKCS#8 format private keys: these are handled automatically but there is no option to produce them.
It is possible to write out DER-encoded encrypted private keys in PKCS#8 format because the encryption details are included at an ASN1 level whereas the traditional format includes them at a PEM level.
PKCS#5 V1.5 AND PKCS#12 ALGORITHMS
Various algorithms can be used with the
-v1
command line option, including PKCS#5 v1.5 and
PKCS#12. These are described in more detail below.
- PBE-MD5-DES
- These algorithms were included in the original PKCS#5 v1.5 specification. They only offer 56 bits of protection since they both use DES.
- PBE-SHA1-RC2-64 | PBE-MD5-RC2-64 | PBE-SHA1-DES
- These algorithms are not mentioned in the original PKCS#5 v1.5 specification but they use the same key derivation algorithm and are supported by some software. They are mentioned in PKCS#5 v2.0. They use either 64-bit RC2 or 56-bit DES.
- PBE-SHA1-RC4-128 | PBE-SHA1-RC4-40 | PBE-SHA1-3DES | PBE-SHA1-2DES
- PBE-SHA1-RC2-128 | PBE-SHA1-RC2-40
- These algorithms use the PKCS#12 password-based encryption algorithm and allow strong encryption algorithms like triple DES or 128-bit RC2 to be used.
PKCS8 EXAMPLES
Convert a private key from traditional to PKCS#5 v2.0 format using triple DES:
$ openssl pkcs8 -in key.pem -topk8
-v2 des3 -out enckey.pem
Convert a private key to PKCS#8 using a PKCS#5 1.5 compatible algorithm (DES):
$ openssl pkcs8 -in key.pem -topk8
-out enckey.pem
Convert a private key to PKCS#8 using a PKCS#12 compatible algorithm (3DES):
$ openssl pkcs8 -in key.pem -topk8 -out enckey.pem \ -v1 PBE-SHA1-3DES
Read a DER-unencrypted PKCS#8 format private key:
$ openssl pkcs8 -inform DER -nocrypt
-in key.der -out key.pem
Convert a private key from any PKCS#8 format to traditional format:
$ openssl pkcs8 -in pk8.pem -out
key.pem
PKCS8 STANDARDS
Test vectors from this PKCS#5 v2.0 implementation were posted to the pkcs-tng mailing list using triple DES, DES and RC2 with high iteration counts; several people confirmed that they could decrypt the private keys produced and therefore it can be assumed that the PKCS#5 v2.0 implementation is reasonably accurate at least as far as these algorithms are concerned.
The format of PKCS#8 DSA (and other) private keys is not well
documented: it is hidden away in PKCS#11 v2.01, section 11.9;
OpenSSL
's
default DSA PKCS#8
private key format complies with this standard.
PKCS8 BUGS
There should be an option that prints out the encryption algorithm in use and other details such as the iteration count.
PKCS#8 using triple DES and PKCS#5 v2.0 should be the default
private key format; for OpenSSL
compatibility,
several of the utilities use the old format at present.
PKCS12
openssl pkcs12 |
[-aes128
| -aes192 | -aes256 | -des
| -des3 ] [-cacerts ]
[-CAfile file]
[-caname name]
[-CApath directory]
[-certfile file]
[-certpbe alg]
[-chain ] [-clcerts ]
[-CSP name]
[-descert ] [-export ]
[-in file]
[-info ]
[-inkey file]
[-keyex ]
[-keypbe alg]
[-keysig ]
[-macalg alg]
[-maciter ]
[-name name]
[-nocerts ] [-nodes ]
[-noiter ] [-nokeys ]
[-nomac ] [-nomaciter ]
[-nomacver ] [-noout ]
[-out file]
[-passin arg]
[-passout arg]
[-twopass ] |
The pkcs12
command allows PKCS#12 files
(sometimes referred to as PFX files) to be created and parsed. PKCS#12 files
are used by several programs including Netscape, MSIE and MS Outlook.
There are a lot of options; the meaning of some depends on whether
a PKCS#12 file is being created or parsed. By default, a PKCS#12 file is
parsed; a PKCS#12 file can be created by using the
-export
option (see below).
PKCS12 PARSING OPTIONS
-aes128
|-aes192
|-aes256
|-des
|-des3
- Use AES, DES, or triple DES, respectively, to encrypt private keys before outputting. The default is triple DES.
-cacerts
- Only output CA certificates (not client certificates).
-clcerts
- Only output client certificates (not CA certificates).
-in
file- This specifies the file of the PKCS#12 file to be parsed. Standard input is used by default.
-info
- Output additional information about the PKCS#12 file structure, algorithms used, and iteration counts.
-nocerts
- No certificates at all will be output.
-nodes
- Don't encrypt the private keys at all.
-nokeys
- No private keys will be output.
-nomacver
- Don't attempt to verify the integrity MAC before reading the file.
-noout
- This option inhibits output of the keys and certificates to the output file version of the PKCS#12 file.
-out
file- The file to write certificates and private keys to, standard output by default. They are all written in PEM format.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-twopass
- Prompt for separate integrity and encryption passwords: most software always assumes these are the same so this option will render such PKCS#12 files unreadable.
PKCS12 FILE CREATION OPTIONS
-CAfile
file- CA storage as a file.
-CApath
directory- CA storage as a directory. This directory must be a standard certificate
directory: that is, a hash of each subject name (using
x509 -hash
) should be linked to each certificate. -caname
name- This specifies the "friendly name" for other certificates. This option may be used multiple times to specify names for all certificates in the order they appear. Netscape ignores friendly names on other certificates, whereas MSIE displays them.
-certfile
file- A file to read additional certificates from.
-certpbe
alg,-keypbe
alg- These options allow the algorithm used to encrypt the private key and
certificates to be selected. Any PKCS#5 v1.5 or PKCS#12 PBE algorithm name
can be used (see the PKCS12 NOTES
section for more information). If a cipher name (as output by the
list-cipher-algorithms
command) is specified then it is used with PKCS#5 v2.0. For interoperability reasons it is advisable to only use PKCS#12 algorithms. -chain
- If this option is present, an attempt is made to include the entire certificate chain of the user certificate. The standard CA store is used for this search. If the search fails, it is considered a fatal error.
-CSP
name- Write name as a Microsoft CSP name.
-descert
- Encrypt the certificate using triple DES; this may render the PKCS#12 file unreadable by some "export grade" software. By default, the private key is encrypted using triple DES and the certificate using 40-bit RC2.
-export
- This option specifies that a PKCS#12 file will be created rather than parsed.
-in
file- The file to read certificates and private keys from, standard input by default. They must all be in PEM format. The order doesn't matter but one private key and its corresponding certificate should be present. If additional certificates are present, they will also be included in the PKCS#12 file.
-inkey
file- File to read private key from. If not present, a private key must be present in the input file.
-keyex
|-keysig
- Specifies that the private key is to be used for key exchange or just
signing. This option is only interpreted by MSIE and similar MS software.
Normally, "export grade" software will only allow 512-bit RSA
keys to be used for encryption purposes, but arbitrary length keys for
signing. The
-keysig
option marks the key for signing only. Signing only keys can be used for S/MIME signing, authenticode (ActiveX control signing) and SSL client authentication; however, due to a bug only MSIE 5.0 and later support the use of signing only keys for SSL client authentication. -macalg
alg- Specify the MAC digest algorithm. If not included then SHA1 is used.
-maciter
- This option is included for compatibility with previous versions; it used to be needed to use MAC iterations counts but they are now used by default.
-name
name- This specifies the "friendly name" for the certificate and private key. This name is typically displayed in list boxes by software importing the file.
-nomac
- Don't attempt to provide the MAC integrity.
-nomaciter
,-noiter
- These options affect the iteration counts on the MAC and key algorithms.
Unless you wish to produce files compatible with MSIE 4.0, you should
leave these options alone.
To discourage attacks by using large dictionaries of common passwords, the algorithm that derives keys from passwords can have an iteration count applied to it: this causes a certain part of the algorithm to be repeated and slows it down. The MAC is used to check the file integrity but since it will normally have the same password as the keys and certificates it could also be attacked. By default, both MAC and encryption iteration counts are set to 2048; using these options the MAC and encryption iteration counts can be set to 1. Since this reduces the file security you should not use these options unless you really have to. Most software supports both MAC and key iteration counts. MSIE 4.0 doesn't support MAC iteration counts, so it needs the
-nomaciter
option. -out
file- This specifies file to write the PKCS#12 file to. Standard output is used by default.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
PKCS12 NOTES
Although there are a large number of options, most of them are
very rarely used. For PKCS#12 file parsing, only -in
and -out
need to be used for PKCS#12 file creation.
-export
and -name
are also
used.
If none of the -clcerts
,
-cacerts
, or -nocerts
options are present, then all certificates will be output in the order they
appear in the input PKCS#12 files. There is no guarantee that the first
certificate present is the one corresponding to the private key. Certain
software which requires a private key and certificate and assumes the first
certificate in the file is the one corresponding to the private key: this
may not always be the case. Using the -clcerts
option will solve this problem by only outputting the certificate
corresponding to the private key. If the CA certificates are required, they
can be output to a separate file using the -nokeys
and -cacerts
options to just output CA
certificates.
The -keypbe
and
-certpbe
algorithms allow the precise encryption
algorithms for private keys and certificates to be specified. Normally, the
defaults are fine but occasionally software can't handle triple DES
encrypted private keys; then the option -keypbe
PBE-SHA1-RC2-40 can be used to reduce the private key
encryption to 40-bit RC2. A complete description of all algorithms is
contained in the PKCS8 section above.
PKCS12 EXAMPLES
Parse a PKCS#12 file and output it to a file:
$ openssl pkcs12 -in file.p12 -out
file.pem
Output only client certificates to a file:
$ openssl pkcs12 -in file.p12
-clcerts -out file.pem
Don't encrypt the private key:
$ openssl pkcs12 -in file.p12 -out
file.pem -nodes
Print some info about a PKCS#12 file:
$ openssl pkcs12 -in file.p12 -info
-noout
Create a PKCS#12 file:
$ openssl pkcs12 -export -in file.pem -out file.p12 \ -name "My Certificate"
Include some extra certificates:
$ openssl pkcs12 -export -in file.pem -out file.p12 \ -name "My Certificate" -certfile othercerts.pem
PKCS12 BUGS
Some would argue that the PKCS#12 standard is one big bug :-)
Versions of OpenSSL
before 0.9.6a had a
bug in the PKCS#12 key generation routines. Under rare circumstances this
could produce a PKCS#12 file encrypted with an invalid key. As a result some
PKCS#12 files which triggered this bug from other implementations (MSIE or
Netscape) could not be decrypted by OpenSSL
and
similarly OpenSSL
could produce PKCS#12 files which
could not be decrypted by other implementations. The chances of producing
such a file are relatively small: less than 1 in 256.
A side effect of fixing this bug is that any old invalidly
encrypted PKCS#12 files can no longer be parsed by the fixed version. Under
such circumstances the pkcs12
utility will report
that the MAC is OK but fail with a decryption error when extracting private
keys.
This problem can be resolved by extracting the private keys and
certificates from the PKCS#12 file using an older version of
OpenSSL
and recreating the PKCS#12 file from the
keys and certificates using a newer version of
OpenSSL
. For example:
$ old-openssl -in bad.p12 -out keycerts.pem $ openssl -in keycerts.pem -export -name "My PKCS#12 file" \ -out fixed.p12
PKEY
openssl pkey |
[cipher]
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-passin arg]
[-passout arg]
[-pubin ] [-pubout ]
[-text ] [-text_pub ] |
The pkey
command processes public or
private keys. They can be converted between various forms and their
components printed out.
The options are as follows:
- cipher
- These options encrypt the private key with the supplied cipher. Any
algorithm name accepted by
EVP_get_cipherbyname
() is acceptable, such asdes3
. -in
file- This specifies the input filename to read a key from, or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for.
-inform
DER | PEM- This specifies the input format, DER or PEM.
-noout
- Do not output the encoded version of the key.
-out
file- This specifies the output filename to write a key to, or standard output if this option is not specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should not be the same as the input filename.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section above.
-pubin
- By default a private key is read from the input file: with this option a public key is read instead.
-pubout
- By default a private key is output: with this option a public key will be output instead. This option is automatically set if the input is a public key.
-text
- Print out the various public or private key components in plain text in addition to the encoded version.
-text_pub
- Print out only public key components even if a private key is being processed.
PKEY EXAMPLES
To remove the pass phrase on an RSA private key:
$ openssl pkey -in key.pem -out keyout.pem
To encrypt a private key using triple DES:
$ openssl pkey -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
$ openssl pkey -in key.pem -outform DER -out keyout.der
To print the components of a private key to standard output:
$ openssl pkey -in key.pem -text -noout
To print the public components of a private key to standard output:
$ openssl pkey -in key.pem -text_pub -noout
To just output the public part of a private key:
$ openssl pkey -in key.pem -pubout -out pubkey.pem
PKEYPARAM
openssl pkeyparam
[-in
file]
[-noout
] [-out
file] [-text
]
The pkey
command processes public or
private keys. They can be converted between various forms and their
components printed out.
The options are as follows:
-in
file- This specifies the input filename to read parameters from, or standard input if this option is not specified.
-noout
- Do not output the encoded version of the parameters.
-out
file- This specifies the output filename to write parameters to, or standard output if this option is not specified.
-text
- Prints out the parameters in plain text in addition to the encoded version.
PKEYPARAM EXAMPLES
Print out text version of parameters:
$ openssl pkeyparam -in param.pem -text
PKEYPARAM NOTES
There are no -inform
or
-outform
options for this command because only PEM
format is supported because the key type is determined by the PEM
headers.
PKEYUTL
openssl pkeyutl |
[-asn1parse ] [-certin ]
[-decrypt ] [-derive ]
[-encrypt ] [-hexdump ]
[-in file]
[-inkey file]
[-keyform DER | PEM]
[-out file]
[-passin arg]
[-peerform DER | PEM]
[-peerkey file]
[-pkeyopt opt:value]
[-pubin ] [-rev ]
[-sigfile file]
[-sign ] [-verify ]
[-verifyrecover ] |
The pkeyutl
command can be used to perform
public key operations using any supported algorithm.
The options are as follows:
-asn1parse
- ASN1parse the output data. This is useful when combined with the
-verifyrecover
option when an ASN1 structure is signed. -certin
- The input is a certificate containing a public key.
-decrypt
- Decrypt the input data using a private key.
-derive
- Derive a shared secret using the peer key.
-encrypt
- Encrypt the input data using a public key.
-hexdump
- Hex dump the output data.
-in
file- Specify the input filename to read data from, or standard input if this option is not specified.
-inkey
file- The input key file. By default it should be a private key.
-keyform
DER | PEM- The key format DER or PEM.
-out
file- Specify the output filename to write to, or standard output by default.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-peerform
DER | PEM- The peer key format DER or PEM.
-peerkey
file- The peer key file, used by key derivation (agreement) operations.
-pkeyopt
opt:value- Public key options.
-pubin
- The input file is a public key.
-rev
- Reverse the order of the input buffer. This is useful for some libraries (such as CryptoAPI) which represent the buffer in little endian format.
-sigfile
file- Signature file (verify operation only).
-sign
- Sign the input data and output the signed result. This requires a private key.
-verify
- Verify the input data against the signature file and indicate if the verification succeeded or failed.
-verifyrecover
- Verify the input data and output the recovered data.
PKEYUTL NOTES
The operations and options supported vary according to the key
algorithm and its implementation. The OpenSSL
operations and options are indicated below.
Unless otherwise mentioned all
algorithms support the
digest:alg option which
specifies the digest in use for sign, verify, and verifyrecover operations.
The value alg should represent a digest name as used
in the
EVP_get_digestbyname
()
function, for example sha1
.
RSA algorithm
The RSA algorithm supports the encrypt, decrypt, sign, verify, and verifyrecover operations in general. Some padding modes only support some of these operations however.
- rsa_padding_mode:mode
- This sets the RSA padding mode. Acceptable values for
mode are
pkcs1
for PKCS#1 padding;none
for no padding;oaep
for OAEP mode;x931
for X9.31 mode; andpss
for PSS.In PKCS#1 padding if the message digest is not set then the supplied data is signed or verified directly instead of using a DigestInfo structure. If a digest is set then a DigestInfo structure is used and its length must correspond to the digest type.
For oeap mode only encryption and decryption is supported.
For x931 if the digest type is set it is used to format the block data; otherwise the first byte is used to specify the X9.31 digest ID. Sign, verify, and verifyrecover can be performed in this mode.
For pss mode only sign and verify are supported and the digest type must be specified.
- rsa_pss_saltlen:len
- For pss mode only this option specifies the salt length. Two special values are supported: -1 sets the salt length to the digest length. When signing -2 sets the salt length to the maximum permissible value. When verifying -2 causes the salt length to be automatically determined based on the PSS block structure.
DSA algorithm
The DSA algorithm supports the sign and verify operations. Currently there are no additional options other than digest. Only the SHA1 digest can be used and this digest is assumed by default.
DH algorithm
The DH algorithm supports the derive operation and no additional options.
EC algorithm
The EC algorithm supports the sign, verify, and derive operations. The sign and verify operations use ECDSA and derive uses ECDH. Currently there are no additional options other than digest. Only the SHA1 digest can be used and this digest is assumed by default.
PKEYUTL EXAMPLES
Sign some data using a private key:
$ openssl pkeyutl -sign -in file -inkey key.pem -out sig
Recover the signed data (e.g. if an RSA key is used):
$ openssl pkeyutl -verifyrecover -in sig -inkey key.pem
Verify the signature (e.g. a DSA key):
$ openssl pkeyutl -verify -in file -sigfile sig \ -inkey key.pem
Sign data using a message digest value (this is currently only valid for RSA):
$ openssl pkeyutl -sign -in file -inkey key.pem \ -out sig -pkeyopt digest:sha256
Derive a shared secret value:
$ openssl pkeyutl -derive -inkey key.pem \ -peerkey pubkey.pem -out secret
PRIME
openssl prime
[-bits
n]
[-checks
n]
[-generate
] [-hex
]
[-safe
] p
The prime
command is used to generate
prime numbers, or to check numbers for primality. Results are probabilistic:
they have an exceedingly high likelihood of being correct, but are not
guaranteed.
The options are as follows:
-bits
n- Specify the number of bits in the generated prime number. Must be used in
conjunction with
-generate
. -checks
n- Perform a Miller-Rabin probabilistic primality test with n iterations. The default is 20.
-generate
- Generate a pseudo-random prime number. Must be used in conjunction with
-bits
. -hex
- Output in hex format.
-safe
- Generate only "safe" prime numbers (i.e. a prime p so that (p-1)/2 is also prime).
- p
- Test if number p is prime.
RAND
openssl rand |
[-base64 ] [-hex ]
[-out file]
num |
The rand
command outputs
num pseudo-random bytes.
The options are as follows:
-base64
- Perform base64 encoding on the output.
-hex
- Specify hexadecimal output.
-out
file- Write to file instead of standard output.
REQ
openssl req |
[-asn1-kludge ] [-batch ]
[-config file]
[-days n]
[-extensions section]
[-in file]
[-inform DER | PEM]
[-key keyfile]
[-keyform DER | PEM]
[-keyout file]
[-md4 | -md5 | -sha1 ]
[-modulus ]
[-nameopt option]
[-new ] [-newhdr ]
[-newkey arg]
[-no-asn1-kludge ] [-nodes ]
[-noout ]
[-out file]
[-outform DER | PEM]
[-passin arg]
[-passout arg]
[-pubkey ]
[-reqexts section]
[-reqopt option]
[-set_serial n]
[-subj arg]
[-subject ] [-text ]
[-utf8 ] [-verbose ]
[-verify ] [-x509 ] |
The req
command primarily creates and
processes certificate requests in PKCS#10 format. It can additionally create
self-signed certificates, for use as root CAs, for example.
The options are as follows:
-asn1-kludge
- By default, the
req
command outputs certificate requests containing no attributes in the correct PKCS#10 format. However certain CAs will only accept requests containing no attributes in an invalid form: this option produces this invalid format.More precisely, the Attributes in a PKCS#10 certificate request are defined as a SET OF Attribute. They are not optional, so if no attributes are present then they should be encoded as an empty SET OF. The invalid form does not include the empty SET OF, whereas the correct form does.
It should be noted that very few CAs still require the use of this option.
-batch
- Non-interactive mode.
-config
file- This allows an alternative configuration file to be specified; this
overrides the compile time filename or any specified in the
OPENSSL_CONF
environment variable. -days
n- When the
-x509
option is being used, this specifies the number of days to certify the certificate for. The default is 30 days. -extensions
section,-reqexts
section- These options specify alternative sections to include certificate
extensions (if the
-x509
option is present) or certificate request extensions. This allows several different sections to be used in the same configuration file to specify requests for a variety of purposes. -in
file- This specifies the input file to read a request
from, or standard input if this option is not specified. A request is only
read if the creation options
-new
and-newkey
are not specified. -inform
DER | PEM- This specifies the input format. The DER argument uses an ASN1 DER-encoded form compatible with the PKCS#10. The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines.
-key
keyfile- This specifies the file to read the private key from. It also accepts PKCS#8 format private keys for PEM format files.
-keyform
DER | PEM- The format of the private key file specified in the
-key
argument. PEM is the default. -keyout
file- This gives the file to write the newly created private key to. If this option is not specified, the filename present in the configuration file is used.
-md5
|-sha1
|-sha256
- This specifies the message digest to sign the request with. This overrides
the digest algorithm specified in the configuration file.
Some public key algorithms may override this choice. For instance, DSA signatures always use SHA1.
-modulus
- This option prints out the value of the modulus of the public key contained in the request.
-nameopt
option,-reqopt
option- These options determine how the subject or issuer names are displayed. The option argument can be a single option or multiple options separated by commas. Alternatively, these options may be used more than once to set multiple options. See the X509 section below for details.
-new
- This option generates a new certificate request. It will prompt the user
for the relevant field values. The actual fields prompted for and their
maximum and minimum sizes are specified in the configuration file and any
requested extensions.
If the
-key
option is not used, it will generate a new RSA private key using information specified in the configuration file. -newhdr
- Adds the word NEW to the PEM file header and footer lines on the outputed request. Some software (Netscape certificate server) and some CAs need this.
-newkey
arg- This option creates a new certificate request and a new private key. The
argument takes one of several forms.
rsa:nbits, where
nbits is the number of bits, generates an RSA key
nbits in size. If nbits is
omitted, i.e.
-newkey rsa
specified, the default key size, specified in the configuration file, is used.All other algorithms support the alg:file form, where file may be an algorithm parameter file, created by the
genpkey -genparam
command or an X.509 certificate for a key with appropriate algorithm.param:file generates a key using the parameter file or certificate file; the algorithm is determined by the parameters. algname:file use algorithm algname and parameter file file: the two algorithms must match or an error occurs. algname just uses algorithm algname, and parameters, if necessary, should be specified via the
-pkeyopt
option.dsa:file generates a DSA key using the parameters in the file file.
-no-asn1-kludge
- Reverses the effect of
-asn1-kludge
. -nodes
- If this option is specified and a private key is created, it will not be encrypted.
-noout
- This option prevents output of the encoded version of the request.
-out
file- This specifies the output file to write to, or standard output by default.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubkey
- Outputs the public key.
-reqopt
option- Customise the output format used with
-text
. The option argument can be a single option or multiple options separated by commas.See the discussion of the
-certopt
option in thex509
command. -set_serial
n- Serial number to use when outputting a self-signed certificate. This may be specified as a decimal value or a hex value if preceded by ‘0x’. It is possible to use negative serial numbers but this is not recommended.
-subj
arg- Replaces subject field of input request with specified data and outputs modified request. The arg must be formatted as /type0=value0/type1=value1/type2=...; characters may be escaped by ‘\’ (backslash); no spaces are skipped.
-subject
- Prints out the request subject (or certificate subject if
-x509
is specified. -text
- Prints out the certificate request in text form.
-utf8
- This option causes field values to be interpreted as UTF8 strings; by default they are interpreted as ASCII. This means that the field values, whether prompted from a terminal or obtained from a configuration file, must be valid UTF8 strings.
-verbose
- Print extra details about the operations being performed.
-verify
- Verifies the signature on the request.
-x509
- This option outputs a self-signed certificate instead of a certificate
request. This is typically used to generate a test certificate or a
self-signed root CA. The extensions added to the certificate (if any) are
specified in the configuration file. Unless specified using the
-set_serial
option, 0 will be used for the serial number.
REQ CONFIGURATION FILE FORMAT
The configuration options are specified in the req section of the configuration file. As with all configuration files, if no value is specified in the specific section (i.e. req) then the initial unnamed or default section is searched too.
The options available are described in detail below.
- attributes
- This specifies the section containing any request attributes: its format
is the same as distinguished_name. Typically these
may contain the
challengePassword
or
unstructuredName
types. They are currently ignored by
OpenSSL
's
request signing utilities, but some CAs might want them. - default_bits
- This specifies the default key size in bits. If not specified, 2048 is
used. It is used if the
-new
option is used. It can be overridden by using the-newkey
option. - default_keyfile
- This is the default file to write a private key to. If not specified, the
key is written to standard output. This can be overridden by the
-keyout
option. - default_md
- This option specifies the digest algorithm to use. Possible values include md5, sha1 and sha256. If not present, SHA256 is used. This option can be overridden on the command line.
- distinguished_name
- This specifies the section containing the distinguished name fields to prompt for when generating a certificate or certificate request. The format is described in the next section.
- encrypt_key
- If this is set to no and a private key is generated, it
is not encrypted. This is equivalent to the
-nodes
command line option. For compatibility, encrypt_rsa_key is an equivalent option. - input_password | output_password
- The passwords for the input private key file (if present) and the output
private key file (if one will be created). The command line options
-passin
and-passout
override the configuration file values. - oid_file
- This specifies a file containing additional OBJECT IDENTIFIERS. Each line of the file should consist of the numerical form of the object identifier, followed by whitespace, then the short name followed by whitespace and finally the long name.
- oid_section
- This specifies a section in the configuration file containing extra object identifiers. Each line should consist of the short name of the object identifier followed by ‘=’ and the numerical form. The short and long names are the same when this option is used.
- prompt
- If set to the value no, this disables prompting of certificate fields and just takes values from the config file directly. It also changes the expected format of the distinguished_name and attributes sections.
- req_extensions
- This specifies the configuration file section containing a list of
extensions to add to the certificate request. It can be overridden by the
-reqexts
command line switch. - string_mask
- This option limits the string types for encoding certain fields. The
following values may be used, limiting strings to the indicated types:
- utf8only
- UTF8String. This is the default, as recommended by PKIX in RFC 2459.
- default
- PrintableString, IA5String, T61String, BMPString, UTF8String.
- pkix
- PrintableString, IA5String, BMPString, UTF8String. This was inspired by the PKIX recommendation in RFC 2459 for certificates generated before 2004, but differs by also permitting IA5String.
- nombstr
- PrintableString, IA5String, T61String, UniversalString. This was a workaround for some ancient software that had problems with the variable-sized BMPString and UTF8String types.
MASK
:number- This is an explicit bitmask of permitted types, where
number is a C-style hex, decimal, or octal
number that's a bit-wise OR of
B_ASN1_*
values from<openssl/asn1.h>
.
- utf8
- If set to the value yes, then field values are interpreted as UTF8 strings; by default they are interpreted as ASCII. This means that the field values, whether prompted from a terminal or obtained from a configuration file, must be valid UTF8 strings.
- x509_extensions
- This specifies the configuration file section containing a list of
extensions to add to a certificate generated when the
-x509
switch is used. It can be overridden by the-extensions
command line switch.
REQ DISTINGUISHED NAME AND ATTRIBUTE SECTION FORMAT
There are two separate formats for the distinguished name and
attribute sections. If the -prompt
option is set to
no, then these sections just consist of field names and
values: for example,
CN=My Name OU=My Organization emailAddress=someone@somewhere.org
This allows external programs (e.g. GUI based) to generate a
template file with all the field names and values and just pass it to
req
. An example of this kind of configuration file
is contained in the REQ EXAMPLES
section.
Alternatively if the -prompt
option is
absent or not set to no, then the file contains field
prompting information. It consists of lines of the form:
fieldName="prompt" fieldName_default="default field value" fieldName_min= 2 fieldName_max= 4
"fieldName" is the field name being used, for example commonName (or CN). The "prompt" string is used to ask the user to enter the relevant details. If the user enters nothing, the default value is used; if no default value is present, the field is omitted. A field can still be omitted if a default value is present, if the user just enters the ‘.’ character.
The number of characters entered must be between the fieldName_min and fieldName_max limits: there may be additional restrictions based on the field being used (for example countryName can only ever be two characters long and must fit in a PrintableString).
Some fields (such as organizationName) can be used more than once in a DN. This presents a problem because configuration files will not recognize the same name occurring twice. To avoid this problem, if the fieldName contains some characters followed by a full stop, they will be ignored. So, for example, a second organizationName can be input by calling it "1.organizationName".
The actual permitted field names are any object
identifier short or long names. These are compiled into
OpenSSL
and include the usual values such as
commonName, countryName,
localityName,
organizationName,
organizationUnitName,
stateOrProvinceName.
Additionally,
emailAddress
is included as well as name,
surname,
givenName
initials and
dnQualifier.
Additional object identifiers can be defined with the oid_file or oid_section options in the configuration file. Any additional fields will be treated as though they were a DirectoryString.
REQ EXAMPLES
Examine and verify a certificate request:
$ openssl req -in req.pem -text
-verify -noout
Create a private key and then generate a certificate request from it:
$ openssl genrsa -out key.pem 2048 $ openssl req -new -key key.pem -out req.pem
The same but just using req:
$ openssl req -newkey rsa:2048
-keyout key.pem -out req.pem
Generate a self-signed root certificate:
$ openssl req -x509 -newkey rsa:2048
-keyout key.pem -out req.pem
Example of a file pointed to by the oid_file option:
1.2.3.4 shortName A longer Name 1.2.3.6 otherName Other longer Name
Example of a section pointed to by oid_section making use of variable expansion:
testoid1=1.2.3.5 testoid2=${testoid1}.6
Sample configuration file prompting for field values:
[ req ] default_bits = 1024 default_keyfile = privkey.pem distinguished_name = req_distinguished_name attributes = req_attributes x509_extensions = v3_ca dirstring_type = nobmp [ req_distinguished_name ] countryName = Country Name (2 letter code) countryName_default = AU countryName_min = 2 countryName_max = 2 localityName = Locality Name (eg, city) organizationalUnitName = Organizational Unit Name (eg, section) commonName = Common Name (eg, YOUR name) commonName_max = 64 emailAddress = Email Address emailAddress_max = 40 [ req_attributes ] challengePassword = A challenge password challengePassword_min = 4 challengePassword_max = 20 [ v3_ca ] subjectKeyIdentifier=hash authorityKeyIdentifier=keyid:always,issuer:always basicConstraints = CA:true
Sample configuration containing all field values:
[ req ] default_bits = 1024 default_keyfile = keyfile.pem distinguished_name = req_distinguished_name attributes = req_attributes prompt = no output_password = mypass [ req_distinguished_name ] C = GB ST = Test State or Province L = Test Locality O = Organization Name OU = Organizational Unit Name CN = Common Name emailAddress = test@email.address [ req_attributes ] challengePassword = A challenge password
REQ NOTES
The header and footer lines in the PEM format are normally:
-----BEGIN CERTIFICATE REQUEST----- -----END CERTIFICATE REQUEST-----
Some software (some versions of Netscape certificate server) instead needs:
-----BEGIN NEW CERTIFICATE REQUEST----- -----END NEW CERTIFICATE REQUEST-----
which is produced with the -newhdr
option
but is otherwise compatible. Either form is accepted transparently on
input.
The certificate requests generated by Xenroll with MSIE have extensions added. It includes the keyUsage extension which determines the type of key (signature only or general purpose) and any additional OIDs entered by the script in an extendedKeyUsage extension.
REQ DIAGNOSTICS
The following messages are frequently asked about:
Using configuration from /some/path/openssl.cnf Unable to load config info
This is followed some time later by...
unable to find 'distinguished_name' in config problems making Certificate Request
The first error message is the clue: it can't find the configuration file! Certain operations (like examining a certificate request) don't need a configuration file so its use isn't enforced. Generation of certificates or requests, however, do need a configuration file. This could be regarded as a bug.
Another puzzling message is this:
Attributes: a0:00
This is displayed when no attributes are present and the request includes the correct empty SET OF structure (the DER encoding of which is 0xa0 0x00). If you just see:
then the SET OF is missing and the encoding is technically invalid
(but it is tolerated). See the description of the command line option
-asn1-kludge
for more information.
REQ ENVIRONMENT VARIABLES
The variable OPENSSL_CONF
, if defined,
allows an alternative configuration file location to be specified; it will
be overridden by the -config
command line switch if
it is present.
REQ BUGS
OpenSSL
's
handling
of T61Strings (aka TeletexStrings) is broken: it effectively treats them as
ISO 8859-1 (Latin 1); Netscape and MSIE have similar behaviour. This can
cause problems if you need characters that aren't available in
PrintableStrings
and you don't want to or can't use
BMPStrings.
As a consequence of the T61String handling, the only correct way
to represent accented characters in OpenSSL
is to
use a BMPString: unfortunately Netscape currently chokes
on these. If you have to use accented characters with Netscape and MSIE then
you currently need to use the invalid T61String form.
The current prompting is not very friendly. It doesn't allow you to confirm what you've just entered. Other things, like extensions in certificate requests, are statically defined in the configuration file. Some of these, like an email address in subjectAltName, should be input by the user.
RSA
openssl rsa |
[-aes128
| -aes192 | -aes256 | -des
| -des3 ] [-check ]
[-in file]
[-inform DER | NET | PEM]
[-modulus ] [-noout ]
[-out file]
[-outform DER | NET | PEM]
[-passin arg]
[-passout arg]
[-pubin ] [-pubout ]
[-sgckey ] [-text ] |
The rsa
command processes RSA keys. They
can be converted between various forms and their components printed out.
Note: this command uses the traditional
SSLeay
compatible format for private key encryption:
newer applications should use the more secure PKCS#8 format using the
pkcs8
utility.
The options are as follows:
-aes128
|-aes192
|-aes256
|-des
|-des3
- These options encrypt the private key with the AES, DES, or the triple DES
ciphers, respectively, before outputting it. A pass phrase is prompted
for. If none of these options are specified, the key is written in plain
text. This means that using the
rsa
utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be used to add or change the pass phrase. These options can only be used with PEM format output files. -check
- This option checks the consistency of an RSA private key.
-in
file- This specifies the input file to read a key from, or standard input if this option is not specified. If the key is encrypted, a pass phrase will be prompted for.
-inform
DER | NET | PEM- This specifies the input format. The DER argument uses an ASN1 DER-encoded form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format. The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines. On input PKCS#8 format private keys are also accepted. The NET form is a format described in the RSA NOTES section.
-noout
- This option prevents output of the encoded version of the key.
-modulus
- This option prints out the value of the modulus of the key.
-out
file- This specifies the output file to write a key to, or standard output if this option is not specified. If any encryption options are set, a pass phrase will be prompted for. The output filename should not be the same as the input filename.
-outform
DER | NET | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-passout
arg- The output file password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubin
- By default, a private key is read from the input file; with this option a public key is read instead.
-pubout
- By default, a private key is output; with this option a public key will be output instead. This option is automatically set if the input is a public key.
-sgckey
- Use the modified NET algorithm used with some versions of Microsoft IIS and SGC keys.
-text
- Prints out the various public or private key components in plain text, in addition to the encoded version.
RSA NOTES
The PEM private key format uses the header and footer lines:
-----BEGIN RSA PRIVATE KEY----- -----END RSA PRIVATE KEY-----
The PEM public key format uses the header and footer lines:
-----BEGIN PUBLIC KEY----- -----END PUBLIC KEY-----
The NET form is a format compatible with older Netscape servers and Microsoft IIS .key files; this uses unsalted RC4 for its encryption. It is not very secure and so should only be used when necessary.
Some newer version of IIS have additional data in the exported
.key files. To use these with the rsa
utility, view
the file with a binary editor and look for the string
"private-key", then trace back to the byte sequence 0x30, 0x82
(this is an ASN1 SEQUENCE). Copy all the data from this point onwards to
another file and use that as the input to the rsa
utility with the -inform
NET
option. If there is an error after entering the password, try the
-sgckey
option.
RSA EXAMPLES
To remove the pass phrase on an RSA private key:
$ openssl rsa -in key.pem -out
keyout.pem
To encrypt a private key using triple DES:
$ openssl rsa -in key.pem -des3 -out
keyout.pem
To convert a private key from PEM to DER format:
$ openssl rsa -in key.pem -outform
DER -out keyout.der
To print out the components of a private key to standard output:
$ openssl rsa -in key.pem -text
-noout
To just output the public part of a private key:
$ openssl rsa -in key.pem -pubout
-out pubkey.pem
RSA BUGS
The command line password arguments don't currently work with NET format.
There should be an option that automatically handles .key files, without having to manually edit them.
RSAUTL
openssl rsautl |
[-asn1parse ] [-certin ]
[-decrypt ] [-encrypt ]
[-hexdump ]
[-in file]
[-inkey file]
[-keyform DER | PEM]
[-oaep | -pkcs | -raw | -ssl ]
[-out file]
[-pubin ] [-sign ]
[-verify ] |
The rsautl
command can be used to sign,
verify, encrypt and decrypt data using the RSA algorithm.
The options are as follows:
-asn1parse
- Asn1parse the output data; this is useful when combined with the
-verify
option. -certin
- The input is a certificate containing an RSA public key.
-decrypt
- Decrypt the input data using an RSA private key.
-encrypt
- Encrypt the input data using an RSA public key.
-hexdump
- Hex dump the output data.
-in
file- This specifies the input file to read data from, or standard input if this option is not specified.
-inkey
file- The input key file, by default it should be an RSA private key.
-keyform
DER | PEM- Private ket format. Default is PEM.
-oaep
|-pkcs
|-raw
|-ssl
- The padding to use: PKCS#1 OAEP, PKCS#1 v1.5 (the default), or no padding,
respectively. For signatures, only
-pkcs
and-raw
can be used. -out
file- Specifies the output file to write to, or standard output by default.
-pubin
- The input file is an RSA public key.
-sign
- Sign the input data and output the signed result. This requires an RSA private key.
-verify
- Verify the input data and output the recovered data.
RSAUTL NOTES
rsautl
, because it uses the RSA algorithm
directly, can only be used to sign or verify small pieces of data.
RSAUTL EXAMPLES
Sign some data using a private key:
$ openssl rsautl -sign -in file
-inkey key.pem -out sig
Recover the signed data:
$ openssl rsautl -verify -in sig
-inkey key.pem
Examine the raw signed data:
$ openssl rsautl -verify -in file -inkey
key.pem -raw -hexdump
0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ 0070 - ff ff ff ff 00 68 65 6c-6c 6f 20 77 6f 72 6c 64 .....hello world
The PKCS#1 block formatting is evident from this. If this was done using encrypt and decrypt, the block would have been of type 2 (the second byte) and random padding data visible instead of the 0xff bytes.
It is possible to analyse the signature of certificates using this
utility in conjunction with asn1parse
. Consider the
self-signed example in certs/pca-cert.pem: running
asn1parse
as follows yields:
$ openssl asn1parse -in
pca-cert.pem
0:d=0 hl=4 l= 742 cons: SEQUENCE 4:d=1 hl=4 l= 591 cons: SEQUENCE 8:d=2 hl=2 l= 3 cons: cont [ 0 ] 10:d=3 hl=2 l= 1 prim: INTEGER :02 13:d=2 hl=2 l= 1 prim: INTEGER :00 16:d=2 hl=2 l= 13 cons: SEQUENCE 18:d=3 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption 29:d=3 hl=2 l= 0 prim: NULL 31:d=2 hl=2 l= 92 cons: SEQUENCE 33:d=3 hl=2 l= 11 cons: SET 35:d=4 hl=2 l= 9 cons: SEQUENCE 37:d=5 hl=2 l= 3 prim: OBJECT :countryName 42:d=5 hl=2 l= 2 prim: PRINTABLESTRING :AU .... 599:d=1 hl=2 l= 13 cons: SEQUENCE 601:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption 612:d=2 hl=2 l= 0 prim: NULL 614:d=1 hl=3 l= 129 prim: BIT STRING
The final BIT STRING contains the actual signature. It can be extracted with:
$ openssl asn1parse -in pca-cert.pem
-out sig -noout -strparse 614
The certificate public key can be extracted with:
$ openssl x509 -in test/testx509.pem
-pubkey -noout >pubkey.pem
The signature can be analysed with:
$ openssl rsautl -in sig -verify
-asn1parse -inkey pubkey.pem -pubin
0:d=0 hl=2 l= 32 cons: SEQUENCE 2:d=1 hl=2 l= 12 cons: SEQUENCE 4:d=2 hl=2 l= 8 prim: OBJECT :md5 14:d=2 hl=2 l= 0 prim: NULL 16:d=1 hl=2 l= 16 prim: OCTET STRING 0000 - f3 46 9e aa 1a 4a 73 c9-37 ea 93 00 48 25 08 b5 .F...Js.7...H%..
This is the parsed version of an ASN1 DigestInfo structure. It can be seen that the digest used was MD5. The actual part of the certificate that was signed can be extracted with:
$ openssl asn1parse -in pca-cert.pem
-out tbs -noout -strparse 4
and its digest computed with:
$ openssl md5 -c tbs
which it can be seen agrees with the recovered value above.
S_CLIENT
openssl s_client |
[-4 | -6 ]
[-bugs ]
[-CAfile file]
[-CApath directory]
[-cert file]
[-check_ss_sig ]
[-cipher cipherlist]
[-connect
host:port | host/port]
[-crl_check ]
[-crl_check_all ] [-crlf ]
[-debug ] [-extended_crl ]
[-ign_eof ]
[-ignore_critical ]
[-issuer_checks ]
[-key keyfile]
[-msg ] [-nbio ]
[-nbio_test ] [-no_ticket ]
[-no_tls1 ] [-no_tls1_1 ]
[-no_tls1_2 ] [-pause ]
[-policy_check ] [-prexit ]
[-proxy host:port]
[-psk key]
[-psk_identity identity]
[-quiet ] [-reconnect ]
[-servername name]
[-showcerts ]
[-starttls protocol]
[-state ] [-tls1 ]
[-tls1_1 ] [-tls1_2 ]
[-tlsextdebug ]
[-verify depth]
[-x509_strict ]
[-xmpphost host] |
The s_client
command implements
a generic SSL/TLS client which connects to a remote host using SSL/TLS. It
is a very useful
diagnostic tool for SSL servers.
The options are as follows:
-4
- Specify that
s_client
should attempt connections using IPv4 only. -6
- Specify that
s_client
should attempt connections using IPv6 only. -bugs
- There are several known bugs in SSL and TLS implementations. Adding this option enables various workarounds.
-CAfile
file- A file containing trusted certificates to use during server authentication and to use when attempting to build the client certificate chain.
-CApath
directory- The directory to use for server certificate
verification. This directory must be in "hash format"; see
-verify
for more information. These are also used when building the client certificate chain. -cert
file- The certificate to use, if one is requested by the server. The default is not to use a certificate.
-check_ss_sig
,-crl_check
,-crl_check_all
,-extended_crl
,-ignore_critical
,-issuer_checks
,-policy_check
,-x509_strict
- Set various certificate chain validation options. See the
VERIFY
command for details. -cipher
cipherlist- This allows the cipher list sent by the client to be modified. Although the server determines which cipher suite is used, it should take the first supported cipher in the list sent by the client. See the CIPHERS section above for more information.
-connect
host:port | host/port- This specifies the host and optional port to connect to. If not specified, an attempt is made to connect to the local host on port 4433. Alternatively, the host and port pair may be separated using a forward-slash character. This form is useful for numeric IPv6 addresses.
-crlf
- This option translates a line feed from the terminal into CR+LF as required by some servers.
-debug
- Print extensive debugging information including a hex dump of all traffic.
-ign_eof
- Inhibit shutting down the connection when end of file is reached in the input.
-key
keyfile- The private key to use. If not specified, the certificate file will be used.
-msg
- Show all protocol messages with hex dump.
-nbio
- Turns on non-blocking I/O.
-nbio_test
- Tests non-blocking I/O.
-no_tls1
|-no_tls1_1
|-no_tls1_2
- By default, the initial handshake uses a method which should be compatible
with servers supporting any version of TLS. These options disable the use
of TLS1.0, 1.1, and 1.2, respectively.
Unfortunately there are a lot of ancient and broken servers in use which cannot handle this technique and will fail to connect.
-no_ticket
- Disable RFC 4507 session ticket support.
-pause
- Pauses 1 second between each read and write call.
-prexit
- Print session information when the program exits. This will always attempt to print out information even if the connection fails. Normally, information will only be printed out once if the connection succeeds. This option is useful because the cipher in use may be renegotiated or the connection may fail because a client certificate is required or is requested only after an attempt is made to access a certain URL. Note: the output produced by this option is not always accurate because a connection might never have been established.
-proxy
host:port- Use the HTTP proxy at host and
port. The connection to the proxy is done in
cleartext and the
-connect
argument is given to the proxy. If not specified, localhost is used as final destination. After that, switch the connection through the proxy to the destination to TLS. -psk
key- Use the PSK key key when using a PSK cipher suite. The key is given as a hexadecimal number without the leading 0x, for example -psk 1a2b3c4d.
-psk_identity
identity- Use the PSK identity identity when using a PSK cipher suite.
-quiet
- Inhibit printing of session and certificate information. This implicitly
turns on
-ign_eof
as well. -reconnect
- Reconnects to the same server 5 times using the same session ID; this can be used as a test that session caching is working.
-servername
name- Include the TLS Server Name Indication (SNI) extension in the ClientHello message, using the specified server name.
-showcerts
- Display the whole server certificate chain: normally only the server certificate itself is displayed.
-starttls
protocol- Send the protocol-specific message(s) to switch to TLS for communication. protocol is a keyword for the intended protocol. Currently, the supported keywords are "ftp", "imap", "smtp", "pop3", and "xmpp".
-state
- Prints out the SSL session states.
-tls1
|-tls1_1
|-tls1_2
- Permit only TLS1.0, 1.1, or 1.2, respectively.
-tlsextdebug
- Print out a hex dump of any TLS extensions received from the server.
-verify
depth- The verify depth to use. This specifies the maximum length of the server certificate chain and turns on server certificate verification. Currently the verify operation continues after errors so all the problems with a certificate chain can be seen. As a side effect the connection will never fail due to a server certificate verify failure.
-xmpphost
hostname- This option, when used with
-starttls
xmpp, specifies the host for the "to" attribute of the stream element. If this option is not specified then the host specified with-connect
will be used.
S_CLIENT CONNECTED COMMANDS
If a connection is established with an SSL server, any data
received from the server is displayed and any key presses will be sent to
the server. When used interactively (which means neither
-quiet
nor -ign_eof
have
been given), the session will be renegotiated if the line begins with an
R; if the line
begins with a Q
or if end of file is reached, the connection will be closed down.
S_CLIENT NOTES
s_client
can be used to debug SSL servers.
To connect to an SSL HTTP server the command:
$ openssl s_client -connect
servername:443
would typically be used (HTTPS uses port 443). If the connection succeeds, an HTTP command can be given such as "GET" to retrieve a web page.
If the handshake fails, there are several possible causes; if it
is nothing obvious like no client certificate, then the
-bugs
, -tls1
,
-tls1_1,
-tls1_2
,
-no_tls1
, -no_tls1_1
, and
-no_tls1_2
options can be tried in case it is a
buggy server.
A frequent problem when attempting to get client certificates
working is that a web client complains it has no certificates or gives an
empty list to choose from. This is normally because the server is not
sending the client's certificate authority in its "acceptable CA
list" when it requests a certificate. By using
s_client
the CA list can be viewed and checked.
However some servers only request client authentication after a specific URL
is requested. To obtain the list in this case it is necessary to use the
-prexit
option and send an HTTP request for an
appropriate page.
If a certificate is specified on the command line using the
-cert
option, it will not be used unless the server
specifically requests a client certificate. Therefore merely including a
client certificate on the command line is no guarantee that the certificate
works.
If there are problems verifying a server certificate, the
-showcerts
option can be used to show the whole
chain.
Compression methods are only supported for
-tls1
.
S_CLIENT BUGS
Because this program has a lot of options and also because some of
the techniques used are rather old, the C source of
s_client
is rather hard to read and not a model of
how things should be done. A typical SSL client program would be much
simpler.
The -verify
option should really exit if
the server verification fails.
The -prexit
option is a bit of a hack. We
should really report information whenever a session is renegotiated.
S_SERVER
openssl s_server |
[-accept port]
[-bugs ]
[-CAfile file]
[-CApath directory]
[-cert file]
[-cipher cipherlist]
[-context id]
[-crl_check ]
[-crl_check_all ] [-crlf ]
[-dcert file]
[-debug ]
[-dhparam file]
[-dkey file]
[-hack ] [-HTTP ]
[-id_prefix arg]
[-key keyfile]
[-msg ] [-nbio ]
[-nbio_test ] [-no_dhe ]
[-no_tls1 ] [-no_tls1_1 ]
[-no_tls1_2 ] [-no_tmp_rsa ]
[-nocert ]
[-psk key]
[-psk_hint hint]
[-quiet ] [-serverpref ]
[-state ] [-tls1 ]
[-tls1_1 ] [-tls1_2 ]
[-Verify depth]
[-verify depth]
[-WWW ] [-www ] |
The s_server
command implements a generic
SSL/TLS server which listens for connections on a given port using
SSL/TLS.
The options are as follows:
-accept
port- The TCP port to listen on for connections. If not specified, 4433 is used.
-bugs
- There are several known bugs in SSL and TLS implementations. Adding this option enables various workarounds.
-CAfile
file- A file containing trusted certificates to use during client authentication and to use when attempting to build the server certificate chain. The list is also used in the list of acceptable client CAs passed to the client when a certificate is requested.
-CApath
directory- The directory to use for client certificate
verification. This directory must be in "hash format"; see
-verify
for more information. These are also used when building the server certificate chain. -cert
file- The certificate to use; most server's cipher suites require the use of a certificate and some require a certificate with a certain public key type: for example the DSS cipher suites require a certificate containing a DSS (DSA) key. If not specified, the file server.pem will be used.
-cipher
cipherlist- This allows the cipher list used by the server to be modified. When the client sends a list of supported ciphers, the first client cipher also included in the server list is used. Because the client specifies the preference order, the order of the server cipherlist is irrelevant. See the CIPHERS section for more information.
-context
id- Sets the SSL context ID. It can be given any string value. If this option is not present, a default value will be used.
-crl_check
,-crl_check_all
- Check the peer certificate has not been revoked by its CA. The CRLs are
appended to the certificate file. With the
-crl_check_all
option, all CRLs of all CAs in the chain are checked. -crlf
- This option translates a line feed from the terminal into CR+LF.
-dcert
file,-dkey
file- Specify an additional certificate and private key; these behave in the
same manner as the
-cert
and-key
options except there is no default if they are not specified (no additional certificate or key is used). As noted above some cipher suites require a certificate containing a key of a certain type. Some cipher suites need a certificate carrying an RSA key and some a DSS (DSA) key. By using RSA and DSS certificates and keys, a server can support clients which only support RSA or DSS cipher suites by using an appropriate certificate. -debug
- Print extensive debugging information including a hex dump of all traffic.
-dhparam
file- The DH parameter file to use. The ephemeral DH cipher suites generate keys
using a set of DH parameters. If not specified, an attempt is made to load
the parameters from the server certificate file. If this fails, a static
set of parameters hard coded into the
s_server
program will be used. -hack
- This option enables a further workaround for some early Netscape SSL code (?).
-HTTP
- Emulates a simple web server. Pages will be resolved relative to the current directory; for example if the URL https://myhost/page.html is requested, the file ./page.html will be loaded. The files loaded are assumed to contain a complete and correct HTTP response (lines that are part of the HTTP response line and headers must end with CRLF).
-id_prefix
arg- Generate SSL/TLS session IDs prefixed by arg. This is mostly useful for testing any SSL/TLS code (e.g. proxies) that wish to deal with multiple servers, when each of which might be generating a unique range of session IDs (e.g. with a certain prefix).
-key
keyfile- The private key to use. If not specified, the certificate file will be used.
-msg
- Show all protocol messages with hex dump.
-nbio
- Turns on non-blocking I/O.
-nbio_test
- Tests non-blocking I/O.
-no_dhe
- If this option is set, no DH parameters will be loaded, effectively disabling the ephemeral DH cipher suites.
-no_tls1
|-no_tls1_1
|-no_tls1_2
- By default, the initial handshake uses a method which should be compatible with clients supporting any version of TLS. These options disable the use of TLS1.0, 1.1, and 1.2, respectively.
-no_tmp_rsa
- Certain export cipher suites sometimes use a temporary RSA key; this option disables temporary RSA key generation.
-nocert
- If this option is set, no certificate is used. This restricts the cipher suites available to the anonymous ones (currently just anonymous DH).
-psk
key- Use the PSK key key when using a PSK cipher suite. The key is given as a hexadecimal number without the leading 0x, for example -psk 1a2b3c4d.
-psk_hint
hint- Use the PSK identity hint hint when using a PSK cipher suite.
-quiet
- Inhibit printing of session and certificate information.
-serverpref
- Use server's cipher preferences.
-state
- Prints out the SSL session states.
-tls1
|-tls1_1
|-tls1_2
- Permit only TLS1.0, 1.1, or 1.2, respectively.
-WWW
- Emulates a simple web server. Pages will be resolved relative to the current directory; for example if the URL https://myhost/page.html is requested, the file ./page.html will be loaded.
-www
- Sends a status message back to the client when it connects. This includes lots of information about the ciphers used and various session parameters. The output is in HTML format so this option will normally be used with a web browser.
-Verify
depth,-verify
depth- The verify depth to use. This specifies the maximum
length of the client certificate chain and makes the server request a
certificate from the client. With the
-Verify
option, the client must supply a certificate or an error occurs. With the-verify
option, a certificate is requested but the client does not have to send one.
S_SERVER CONNECTED COMMANDS
If a connection request is established with an SSL client and
neither the -www
nor the
-WWW
option has been used, then normally any data
received from the client is displayed and any key presses will be sent to
the client.
Certain single letter commands are also recognized which perform special operations: these are listed below.
- P
- Send some plain text down the underlying TCP connection: this should cause the client to disconnect due to a protocol violation.
- Q
- End the current SSL connection and exit.
- q
- End the current SSL connection, but still accept new connections.
- R
- Renegotiate the SSL session and request a client certificate.
- r
- Renegotiate the SSL session.
- S
- Print out some session cache status information.
S_SERVER NOTES
s_server
can be used to debug SSL clients.
To accept connections from a web browser the command:
$ openssl s_server -accept 443
-www
can be used, for example.
Most web browsers (in particular Netscape and MSIE) only support
RSA cipher suites, so they cannot connect to servers which don't use a
certificate carrying an RSA key or a version of
OpenSSL
with RSA disabled.
Although specifying an empty list of CAs when requesting a client certificate is strictly speaking a protocol violation, some SSL clients interpret this to mean any CA is acceptable. This is useful for debugging purposes.
The session parameters can printed out using the
sess_id
program.
S_SERVER BUGS
Because this program has a lot of options and also because some of
the techniques used are rather old, the C source of
s_server
is rather hard to read and not a model of
how things should be done. A typical SSL server program would be much
simpler.
The output of common ciphers is wrong: it just gives the list of
ciphers that OpenSSL
recognizes and the client
supports.
There should be a way for the s_server
program to print out details of any unknown cipher suites a client says it
supports.
S_TIME
openssl s_time |
[-bugs ]
[-CAfile file]
[-CApath directory]
[-cert file]
[-cipher cipherlist]
[-connect host:port]
[-key keyfile]
[-nbio ] [-new ]
[-no_shutdown ] [-reuse ]
[-time seconds]
[-verify depth]
[-www page] |
The s_client
command implements a generic
SSL/TLS client which connects to a remote host using SSL/TLS. It can request
a page from the server and includes the time to transfer the payload data in
its timing measurements. It measures the number of connections within a
given timeframe, the amount of data transferred (if any), and calculates the
average time spent for one connection.
The options are as follows:
-bugs
- There are several known bugs in SSL and TLS implementations. Adding this option enables various workarounds.
-CAfile
file- A file containing trusted certificates to use during server authentication and to use when attempting to build the client certificate chain.
-CApath
directory- The directory to use for server certificate verification. This directory
must be in "hash format"; see
verify
for more information. These are also used when building the client certificate chain. -cert
file- The certificate to use, if one is requested by the server. The default is not to use a certificate. The file is in PEM format.
-cipher
cipherlist- This allows the cipher list sent by the client to be modified. Although
the server determines which cipher suite is used, it should take the first
supported cipher in the list sent by the client. See the
ciphers
command for more information. -connect
host:port- This specifies the host and optional port to connect to.
-key
keyfile- The private key to use. If not specified, the certificate file will be used. The file is in PEM format.
-nbio
- Turns on non-blocking I/O.
-new
- Performs the timing test using a new session ID for each connection. If
neither
-new
nor-reuse
are specified, they are both on by default and executed in sequence. -no_shutdown
- Shut down the connection without sending a “close notify” shutdown alert to the server.
-reuse
- Performs the timing test using the same session ID; this can be used as a
test that session caching is working. If neither
-new
nor-reuse
are specified, they are both on by default and executed in sequence. -time
seconds- Specifies how long (in seconds)
s_time
should establish connections and optionally transfer payload data from a server. The default is 30 seconds. Server and client performance and the link speed determine how many connectionss_time
can establish. -verify
depth- The verify depth to use. This specifies the maximum length of the server certificate chain and turns on server certificate verification. Currently the verify operation continues after errors, so all the problems with a certificate chain can be seen. As a side effect, the connection will never fail due to a server certificate verify failure.
-www
page- This specifies the page to GET from the server. A value of
‘/’ gets the index.htm[l] page. If this parameter is not
specified,
s_time
will only perform the handshake to establish SSL connections but not transfer any payload data.
S_TIME NOTES
s_client
can be used to measure the
performance of an SSL connection. To connect to an SSL HTTP server and get
the default page the command
$ openssl s_time -connect servername:443 -www / -CApath yourdir \ -CAfile yourfile.pem -cipher commoncipher
would typically be used (HTTPS uses port 443).
“commoncipher” is a cipher to which both client and server can
agree; see the ciphers
command for details.
If the handshake fails, there are several possible causes: if it
is nothing obvious like no client certificate, the
-bugs
option can be tried in case it is a buggy
server.
A frequent problem when attempting to get client certificates
working is that a web client complains it has no certificates or gives an
empty list to choose from. This is normally because the server is not
sending the clients certificate authority in its "acceptable CA
list" when it requests a certificate. By using
s_client
, the CA list can be viewed and checked.
However some servers only request client authentication after a specific URL
is requested. To obtain the list in this case, it is necessary to use the
-prexit
option of s_client
and send an HTTP request for an appropriate page.
If a certificate is specified on the command line using the
-cert
option, it will not be used unless the server
specifically requests a client certificate. Therefore merely including a
client certificate on the command line is no guarantee that the certificate
works.
S_TIME BUGS
Because this program does not have all the options of the
s_client
program to turn protocols on and off, you
may not be able to measure the performance of all protocols with all
servers.
The -verify
option should really exit if
the server verification fails.
SESS_ID
openssl sess_id |
[-cert ]
[-context ID]
[-in file]
[-inform DER | PEM]
[-noout ]
[-out file]
[-outform DER | PEM]
[-text ] |
The sess_id
program processes the encoded
version of the SSL session structure and optionally prints out SSL session
details (for example the SSL session master key) in human readable format.
Since this is a diagnostic tool that needs some knowledge of the SSL
protocol to use properly, most users will not need to use it.
The options are as follows:
-cert
- If a certificate is present in the session, it will be output using this
option; if the
-text
option is also present, then it will be printed out in text form. -context
ID- This option can set the session ID so the output session information uses the supplied ID. The ID can be any string of characters. This option won't normally be used.
-in
file- This specifies the input file to read session information from, or standard input by default.
-inform
DER | PEM- This specifies the input format. The DER argument uses an ASN1 DER-encoded format containing session details. The precise format can vary from one version to the next. The PEM form is the default format: it consists of the DER format base64-encoded with additional header and footer lines.
-noout
- This option prevents output of the encoded version of the session.
-out
file- This specifies the output file to write session information to, or standard output if this option is not specified.
-outform
DER | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -text
- Prints out the various public or private key components in plain text in addition to the encoded version.
SESS_ID OUTPUT
Typical output:
SSL-Session: Protocol : TLSv1 Cipher : 0016 Session-ID: 871E62626C554CE95488823752CBD5F3673A3EF3DCE9C67BD916C809914B40ED Session-ID-ctx: 01000000 Master-Key: A7CEFC571974BE02CAC305269DC59F76EA9F0B180CB6642697A68251F2D2BB57E51DBBB4C7885573192AE9AEE220FACD Key-Arg : None Start Time: 948459261 Timeout : 300 (sec) Verify return code 0 (ok)
These are described below in more detail.
- Protocol
- This is the protocol in use.
- Cipher
- The cipher used is the actual raw SSL or TLS cipher code; see the SSL or TLS specifications for more information.
- Session-ID
- The SSL session ID in hex format.
- Session-ID-ctx
- The session ID context in hex format.
- Master-Key
- This is the SSL session master key.
- Key-Arg
- The key argument; this is only used in SSL v2.
- Start Time
- This is the session start time, represented as an integer in standard UNIX format.
- Timeout
- The timeout in seconds.
- Verify return code
- This is the return code when an SSL client certificate is verified.
SESS_ID NOTES
The PEM-encoded session format uses the header and footer lines:
-----BEGIN SSL SESSION PARAMETERS----- -----END SSL SESSION PARAMETERS-----
Since the SSL session output contains the master key, it is possible to read the contents of an encrypted session using this information. Therefore appropriate security precautions should be taken if the information is being output by a "real" application. This is, however, strongly discouraged and should only be used for debugging purposes.
SESS_ID BUGS
The cipher and start time should be printed out in human readable form.
SMIME
openssl smime |
[-aes128
| -aes192 | -aes256 | -des | -des3
| -rc2-40 | -rc2-64 | -rc2-128 ]
[-binary ]
[-CAfile file]
[-CApath directory]
[-certfile file]
[-check_ss_sig ]
[-content file]
[-crl_check ]
[-crl_check_all ]
[-decrypt ] [-encrypt ]
[-extended_crl ]
[-from addr]
[-ignore_critical ]
[-in file]
[-indef ]
[-inform DER | PEM | SMIME]
[-inkey file]
[-issuer_checks ]
[-keyform PEM]
[-md digest]
[-noattr ] [-nocerts ]
[-nochain ] [-nodetach ]
[-noindef ] [-nointern ]
[-nosigs ] [-noverify ]
[-out file]
[-outform DER | PEM | SMIME]
[-passin arg]
[-pk7out ] [-policy_check ]
[-recip file]
[-resign ] [-sign ]
[-signer file]
[-stream ]
[-subject s]
[-text ]
[-to addr]
[-verify ] [-x509_strict ]
[cert.pem ...] |
The smime
command handles
S/MIME mail. It can encrypt, decrypt, sign, and verify
S/MIME messages.
There are six operation options that set the type of operation to be performed. The meaning of the other options varies according to the operation type.
The six operation options are as follows:
-decrypt
- Decrypt mail using the supplied certificate and private key. Expects an encrypted mail message in MIME format for the input file. The decrypted mail is written to the output file.
-encrypt
- Encrypt mail for the given recipient certificates. Input file is the message to be encrypted. The output file is the encrypted mail in MIME format.
-pk7out
- Takes an input message and writes out a PEM-encoded PKCS#7 structure.
-resign
- Resign a message: take an existing message and one or more new signers.
-sign
- Sign mail using the supplied certificate and private key. Input file is the message to be signed. The signed message in MIME format is written to the output file.
-verify
- Verify signed mail. Expects a signed mail message on input and outputs the signed data. Both clear text and opaque signing is supported.
The remaining options are as follows:
-aes128
|-aes192
|-aes256
|-des
|-des3
|-rc2-40
|-rc2-64
|-rc2-128
- The encryption algorithm to use. 128-, 192-, or 256-bit AES, DES (56
bits), triple DES (168 bits), or 40-, 64-, or 128-bit RC2, respectively;
if not specified, 40-bit RC2 is used. Only used with
-encrypt
. -binary
- Normally, the input message is converted to "canonical" format which is effectively using CR and LF as end of line - as required by the S/MIME specification. When this option is present no translation occurs. This is useful when handling binary data which may not be in MIME format.
-CAfile
file- A file containing trusted CA certificates; only used
with
-verify
. -CApath
directory- A directory containing trusted CA certificates; only
used with
-verify
. This directory must be a standard certificate directory: that is, a hash of each subject name (usingx509 -hash
) should be linked to each certificate. - cert.pem ...
- One or more certificates of message recipients: used when encrypting a message.
-certfile
file- Allows additional certificates to be specified. When signing, these will be included with the message. When verifying, these will be searched for the signers' certificates. The certificates should be in PEM format.
-check_ss_sig
,-crl_check
,-crl_check_all
,-extended_crl
,-ignore_critical
,-issuer_checks
,-policy_check
,-x509_strict
- Set various certificate chain validation options. See the
VERIFY
command for details. -content
file- This specifies a file containing the detached content. This is only useful
with the
-verify
command. This is only usable if the PKCS#7 structure is using the detached signature form where the content is not included. This option will override any content if the input format is S/MIME and it uses the multipart/signed MIME content type. -from
addr,-subject
s,-to
addr- The relevant mail headers. These are included outside the signed portion of a message so they may be included manually. When signing, many S/MIME mail clients check that the signer's certificate email address matches the From: address.
-in
file- The input message to be encrypted or signed or the MIME message to be decrypted or verified.
-indef
- Enable streaming I/O for encoding operations. This permits single pass processing of data without the need to hold the entire contents in memory, potentially supporting very large files. Streaming is automatically set for S/MIME signing with detached data if the output format is SMIME; it is currently off by default for all other operations.
-inform
DER | PEM | SMIME- This specifies the input format for the PKCS#7 structure. The default is
SMIME, which reads an S/MIME format
message. PEM and DER format
change this to expect PEM and DER format PKCS#7 structures instead. This
currently only affects the input format of the PKCS#7 structure; if no
PKCS#7 structure is being input (for example with
-encrypt
or-sign
), this option has no effect. -inkey
file- The private key to use when signing or decrypting. This must match the
corresponding certificate. If this option is not specified, the private
key must be included in the certificate file specified with the
-recip
or-signer
file. When signing, this option can be used multiple times to specify successive keys. -keyform
PEM- Input private key format.
-md
digest- The digest algorithm to use when signing or resigning. If not present then the default digest algorithm for the signing key is used (usually SHA1).
-noattr
- Normally, when a message is signed a set of attributes are included which include the signing time and supported symmetric algorithms. With this option they are not included.
-nocerts
- When signing a message, the signer's certificate is normally included;
with this option it is excluded. This will reduce the size of the signed
message but the verifier must have a copy of the signer's certificate
available locally (passed using the
-certfile
option, for example). -nochain
- Do not do chain verification of signers' certificates: that is, don't use the certificates in the signed message as untrusted CAs.
-nodetach
- When signing a message use opaque signing: this form is more resistant to translation by mail relays but it cannot be read by mail agents that do not support S/MIME. Without this option cleartext signing with the MIME type multipart/signed is used.
-noindef
- Disable streaming I/O where it would produce an encoding of indefinite length. This option currently has no effect. In future streaming will be enabled by default on all relevant operations and this option will disable it.
-nointern
- When verifying a message, normally certificates (if any) included in the
message are searched for the signing certificate. With this option, only
the certificates specified in the
-certfile
option are used. The supplied certificates can still be used as untrusted CAs however. -nosigs
- Don't try to verify the signatures on the message.
-noverify
- Do not verify the signer's certificate of a signed message.
-out
file- The message text that has been decrypted or verified, or the output MIME format message that has been signed or verified.
-outform
DER | PEM | SMIME- This specifies the output format for the PKCS#7 structure. The default is
SMIME, which writes an S/MIME format
message. PEM and DER format
change this to write PEM and DER format PKCS#7 structures instead. This
currently only affects the output format of the PKCS#7 structure; if no
PKCS#7 structure is being output (for example with
-verify
or-decrypt
) this option has no effect. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-recip
file- The recipients certificate when decrypting a message. This certificate must match one of the recipients of the message or an error occurs.
-signer
file- A signing certificate when signing or resigning a message; this option can be used multiple times if more than one signer is required. If a message is being verified, the signer's certificates will be written to this file if the verification was successful.
-stream
- The same as
-indef
. -text
- This option adds plain text (text/plain) MIME headers to the supplied message if encrypting or signing. If decrypting or verifying, it strips off text headers: if the decrypted or verified message is not of MIME type text/plain then an error occurs.
SMIME NOTES
The MIME message must be sent without any blank lines between the headers and the output. Some mail programs will automatically add a blank line. Piping the mail directly to an MTA is one way to achieve the correct format.
The supplied message to be signed or encrypted must include the
necessary MIME headers or many S/MIME
clients won't display it properly (if at all). You can use the
-text
option to automatically add plain text
headers.
A "signed and encrypted" message is one where a signed message is then encrypted. This can be produced by encrypting an already signed message: see the SMIME EXAMPLES section.
This version of the program only allows one signer per message, but it will verify multiple signers on received messages. Some S/MIME clients choke if a message contains multiple signers. It is possible to sign messages "in parallel" by signing an already signed message.
The options -encrypt
and
-decrypt
reflect common usage in
S/MIME clients. Strictly speaking these process PKCS#7
enveloped data: PKCS#7 encrypted data is used for other purposes.
The -resign
option uses an existing
message digest when adding a new signer. This means that attributes must be
present in at least one existing signer using the same message digest or
this operation will fail.
The -stream
and
-indef
options enable experimental streaming I/O
support. As a result the encoding is BER using indefinite length constructed
encoding and no longer DER. Streaming is supported for the
-encrypt
and -sign
operations if the content is not detached.
Streaming is always used for the -sign
operation with detached data but since the content is no longer part of the
PKCS#7 structure the encoding remains DER.
SMIME EXIT CODES
- 0
- The operation was completely successful.
- 1
- An error occurred parsing the command options.
- 2
- One of the input files could not be read.
- 3
- An error occurred creating the PKCS#7 file or when reading the MIME message.
- 4
- An error occurred decrypting or verifying the message.
- 5
- The message was verified correctly, but an error occurred writing out the signer's certificates.
SMIME EXAMPLES
Create a cleartext signed message:
$ openssl smime -sign -in message.txt -text -out mail.msg \ -signer mycert.pem
Create an opaque signed message:
$ openssl smime -sign -in message.txt -text -out mail.msg \ -nodetach -signer mycert.pem
Create a signed message, include some additional certificates and read the private key from another file:
$ openssl smime -sign -in in.txt -text -out mail.msg \ -signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
Create a signed message with two signers:
openssl smime -sign -in message.txt -text -out mail.msg \ -signer mycert.pem -signer othercert.pem
Send a signed message under UNIX directly to sendmail(8), including headers:
$ openssl smime -sign -in in.txt -text -signer mycert.pem \ -from steve@openssl.org -to someone@somewhere \ -subject "Signed message" | sendmail someone@somewhere
Verify a message and extract the signer's certificate if successful:
$ openssl smime -verify -in mail.msg -signer user.pem \ -out signedtext.txt
Send encrypted mail using triple DES:
$ openssl smime -encrypt -in in.txt -from steve@openssl.org \ -to someone@somewhere -subject "Encrypted message" \ -des3 -out mail.msg user.pem
Sign and encrypt mail:
$ openssl smime -sign -in ml.txt -signer my.pem -text | \ openssl smime -encrypt -out mail.msg \ -from steve@openssl.org -to someone@somewhere \ -subject "Signed and Encrypted message" -des3 user.pem
Note: The encryption command does not include
the -text
option because the message being encrypted
already has MIME headers.
Decrypt mail:
$ openssl smime -decrypt -in mail.msg -recip mycert.pem \ -inkey key.pem"
The output from Netscape form signing is a PKCS#7 structure with the detached signature format. You can use this program to verify the signature by line wrapping the base64-encoded structure and surrounding it with:
-----BEGIN PKCS7----- -----END PKCS7-----
and using the command:
$ openssl smime -verify -inform PEM -in signature.pem \ -content content.txt
Alternatively, you can base64 decode the signature and use:
$ openssl smime -verify -inform DER -in signature.der \ -content content.txt
Create an encrypted message using 128-bit AES:
openssl smime -encrypt -in plain.txt -aes128 \ -out mail.msg cert.pem
Add a signer to an existing message:
openssl smime -resign -in mail.msg -signer newsign.pem \ -out mail2.msg
SMIME BUGS
The MIME parser isn't very clever: it seems to handle most messages that I've thrown at it, but it may choke on others.
The code currently will only write out the signer's certificate to a file: if the signer has a separate encryption certificate this must be manually extracted. There should be some heuristic that determines the correct encryption certificate.
Ideally, a database should be maintained of a certificate for each email address.
The code doesn't currently take note of the permitted symmetric encryption algorithms as supplied in the SMIMECapabilities signed attribute. This means the user has to manually include the correct encryption algorithm. It should store the list of permitted ciphers in a database and only use those.
No revocation checking is done on the signer's certificate.
The current code can only handle S/MIME v2 messages; the more complex S/MIME v3 structures may cause parsing errors.
SMIME HISTORY
The use of multiple -signer
options and
the -resign
command were first added in
OpenSSL
1.0.0.
SPEED
openssl speed |
[aes ] [aes-128-cbc ]
[aes-192-cbc ]
[aes-256-cbc ]
[aes-128-gcm ]
[aes-256-gcm ] [blowfish ]
[bf-cbc ] [cast ]
[cast-cbc ]
[chacha20-poly1305 ] [des ]
[des-cbc ] [des-ede3 ]
[dsa ] [dsa512 ]
[dsa1024 ] [dsa2048 ]
[hmac ] [md4 ]
[md5 ] [rc2 ]
[rc2-cbc ] [rc4 ]
[rmd160 ] [rsa ]
[rsa512 ] [rsa1024 ]
[rsa2048 ] [rsa4096 ]
[sha1 ] [-decrypt ]
[-elapsed ]
[-evp e]
[-mr ]
[-multi number] |
The speed
command is used to test the
performance of cryptographic algorithms.
- [
zero or more test algorithms
] - If any options are given,
speed
tests those algorithms, otherwise all of the above are tested. -decrypt
- Time decryption instead of encryption (only EVP).
-elapsed
- Measure time in real time instead of CPU user time.
-evp
e- Use EVP e.
-mr
- Produce machine readable output.
-multi
number- Run number benchmarks in parallel.
TS
openssl ts |
-query
[-md4 | -md5 | -ripemd160 | -sha1 ]
[-cert ]
[-config configfile]
[-data file_to_hash]
[-digest digest_bytes]
[-in request.tsq]
[-no_nonce ]
[-out request.tsq]
[-policy object_id]
[-text ] |
openssl ts |
-reply
[-chain certs_file.pem]
[-config configfile]
[-in response.tsr]
[-inkey private.pem]
[-out response.tsr]
[-passin arg]
[-policy object_id]
[-queryfile request.tsq]
[-section tsa_section]
[-signer tsa_cert.pem]
[-text ] [-token_in ]
[-token_out ] |
openssl ts |
-verify
[-CAfile trusted_certs.pem]
[-CApath trusted_cert_path]
[-data file_to_hash]
[-digest digest_bytes]
[-in response.tsr]
[-queryfile request.tsq]
[-token_in ]
[-untrusted cert_file.pem] |
The ts
command is a basic Time Stamping
Authority (TSA) client and server application as specified in RFC 3161
(Time-Stamp Protocol, TSP). A TSA can be part of a PKI deployment and its
role is to provide long term proof of the existence of a certain datum
before a particular time. Here is a brief description of the protocol:
- The TSA client computes a one-way hash value for a data file and sends the hash to the TSA.
- The TSA attaches the current date and time to the received hash value, signs them and sends the time stamp token back to the client. By creating this token the TSA certifies the existence of the original data file at the time of response generation.
- The TSA client receives the time stamp token and verifies the signature on it. It also checks if the token contains the same hash value that it had sent to the TSA.
There is one DER-encoded protocol data unit defined for
transporting a time stamp request to the TSA and one for sending the time
stamp response back to the client. The ts
command
has three main functions: creating a time stamp request based on a data
file; creating a time stamp response based on a request; and verifying if a
response corresponds to a particular request or a data file.
There is no support for sending the requests/responses automatically over HTTP or TCP yet as suggested in RFC 3161. Users must send the requests either by FTP or email.
The -query
switch can be used for creating
and printing a time stamp request with the following options:
-cert
- The TSA is expected to include its signing certificate in the response.
-config
configfile- The configuration file to use. This option overrides the
OPENSSL_CONF
environment variable. Only the OID section of the config file is used with the-query
command. -data
file_to_hash- The data file for which the time stamp request needs to be created. stdin
is the default if neither the
-data
nor the-digest
option is specified. -digest
digest_bytes- It is possible to specify the message imprint explicitly without the data file. The imprint must be specified in a hexadecimal format, two characters per byte, the bytes optionally separated by colons (e.g. 1A:F6:01:... or 1AF601...). The number of bytes must match the message digest algorithm in use.
-in
request.tsq- This option specifies a previously created time stamp request in DER format that will be printed into the output file. Useful when you need to examine the content of a request in human-readable format.
-md4|md5|ripemd160|sha|sha1
- The message digest to apply to the data file. It supports all the message
digest algorithms that are supported by the
dgst
command. The default is SHA-1. -no_nonce
- No nonce is specified in the request if this option is given. Otherwise a 64-bit long pseudo-random none is included in the request. It is recommended to use nonce to protect against replay-attacks.
-out
request.tsq- Name of the output file to which the request will be written. The default is stdout.
-policy
object_id- The policy that the client expects the TSA to use for creating the time stamp token. Either the dotted OID notation or OID names defined in the config file can be used. If no policy is requested the TSA will use its own default policy.
-text
- If this option is specified the output is in human-readable text format instead of DER.
A time stamp response (TimeStampResp) consists of a response
status and the time stamp token itself (ContentInfo), if the token
generation was successful. The -reply
command is for
creating a time stamp response or time stamp token based on a request and
printing the response/token in human-readable format. If
-token_out
is not specified the output is always a
time stamp response (TimeStampResp), otherwise it is a time stamp token
(ContentInfo).
-chain
certs_file.pem- The collection of certificates, in PEM format, that will be included in
the response in addition to the signer certificate if the
-cert
option was used for the request. This file is supposed to contain the certificate chain for the signer certificate from its issuer upwards. The-reply
command does not build a certificate chain automatically. -config
configfile- The configuration file to use. This option overrides the
OPENSSL_CONF
environment variable. See TS CONFIGURATION FILE OPTIONS for configurable variables. -in
response.tsr- Specifies a previously created time stamp response or time stamp token, if
-token_in
is also specified, in DER format that will be written to the output file. This option does not require a request; it is useful, for example, when you need to examine the content of a response or token or you want to extract the time stamp token from a response. If the input is a token and the output is a time stamp response a default “granted” status info is added to the token. -inkey
private.pem- The signer private key of the TSA in PEM format. Overrides the
signer_key
config file option. -out
response.tsr- The response is written to this file. The format and content of the file
depends on other options (see
-text
and-token_out
). The default is stdout. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-policy
object_id- The default policy to use for the response unless the client explicitly
requires a particular TSA policy. The OID can be specified either in
dotted notation or with its name. Overrides the
default_policy
config file option. -queryfile
request.tsq- The name of the file containing a DER-encoded time stamp request.
-section
tsa_section- The name of the config file section containing the settings for the response generation. If not specified the default TSA section is used; see TS CONFIGURATION FILE OPTIONS for details.
-signer
tsa_cert.pem- The signer certificate of the TSA in PEM format. The TSA signing
certificate must have exactly one extended key usage assigned to it:
timeStamping. The extended key usage must also be critical, otherwise the
certificate is going to be refused. Overrides the
signer_cert
variable of the config file. -text
- If this option is specified the output is human-readable text format instead of DER.
-token_in
- This flag can be used together with the
-in
option and indicates that the input is a DER-encoded time stamp token (ContentInfo) instead of a time stamp response (TimeStampResp). -token_out
- The output is a time stamp token (ContentInfo) instead of time stamp response (TimeStampResp).
The -verify
command is for verifying if a
time stamp response or time stamp token is valid and matches a particular
time stamp request or data file. The -verify
command
does not use the configuration file.
-CAfile
trusted_certs.pem- The name of the file containing a set of trusted self-signed CA
certificates in PEM format. See the similar option of
verify
for additional details. Either this option or-CApath
must be specified. -CApath
trusted_cert_path- The name of the directory containing the trused CA certificates of the
client. See the similar option of
verify
for additional details. Either this option or-CAfile
must be specified. -data
file_to_hash- The response or token must be verified against
file_to_hash. The file is hashed with the message
digest algorithm specified in the token. The
-digest
and-queryfile
options must not be specified with this one. -digest
digest_bytes- The response or token must be verified against the message digest
specified with this option. The number of bytes must match the message
digest algorithm specified in the token. The
-data
and-queryfile
options must not be specified with this one. -in
response.tsr- The time stamp response that needs to be verified, in DER format. This option in mandatory.
-queryfile
request.tsq- The original time stamp request, in DER format. The
-data
and-digest
options must not be specified with this one. -token_in
- This flag can be used together with the
-in
option and indicates that the input is a DER-encoded time stamp token (ContentInfo) instead of a time stamp response (TimeStampResp). -untrusted
cert_file.pem- Set of additional untrusted certificates in PEM format which may be needed when building the certificate chain for the TSA's signing certificate. This file must contain the TSA signing certificate and all intermediate CA certificates unless the response includes them.
TS CONFIGURATION FILE OPTIONS
The -query
and
-reply
options make use of a configuration file
defined by the OPENSSL_CONF
environment variable.
The -query
option uses only the symbolic OID names
section and it can work without it. However, the
-reply
option needs the config file for its
operation.
When there is a command line switch equivalent of a variable the switch always overrides the settings in the config file.
tsa
section,default_tsa
- This is the main section and it specifies the name of another section that
contains all the options for the
-reply
option. This default section can be overridden with the-section
command line switch. oid_file
- See
ca
for a description. oid_section
- See
ca
for a description. serial
- The name of the file containing the hexadecimal serial number of the last time stamp response created. This number is incremented by 1 for each response. If the file does not exist at the time of response generation a new file is created with serial number 1. This parameter is mandatory.
signer_cert
- TSA signing certificate, in PEM format. The same as the
-signer
command line option. certs
- A file containing a set of PEM-encoded certificates that need to be
included in the response. The same as the
-chain
command line option. signer_key
- The private key of the TSA, in PEM format. The same as the
-inkey
command line option. default_policy
- The default policy to use when the request does not mandate any policy.
The same as the
-policy
command line option. other_policies
- Comma separated list of policies that are also acceptable by the TSA and used only if the request explicitly specifies one of them.
digests
- The list of message digest algorithms that the TSA accepts. At least one algorithm must be specified. This parameter is mandatory.
accuracy
- The accuracy of the time source of the TSA in seconds, milliseconds and microseconds. For example, secs:1, millisecs:500, microsecs:100. If any of the components is missing, zero is assumed for that field.
clock_precision_digits
- Specifies the maximum number of digits, which represent the fraction of seconds, that need to be included in the time field. The trailing zeroes must be removed from the time, so there might actually be fewer digits, or no fraction of seconds at all. The maximum value is 6; the default is 0.
ordering
- If this option is yes, the responses generated by this TSA can always be ordered, even if the time difference between two responses is less than the sum of their accuracies. The default is no.
tsa_name
- Set this option to yes if the subject name of the TSA must be included in the TSA name field of the response. The default is no.
ess_cert_id_chain
- The SignedData objects created by the TSA always contain the certificate
identifier of the signing certificate in a signed attribute (see RFC 2634,
Enhanced Security Services). If this option is set to yes and either the
certs
variable or the-chain
option is specified then the certificate identifiers of the chain will also be included in the SigningCertificate signed attribute. If this variable is set to no, only the signing certificate identifier is included. The default is no.
TS ENVIRONMENT VARIABLES
OPENSSL_CONF
contains the path of the
configuration file and can be overridden by the
-config
command line option.
TS EXAMPLES
All the examples below presume that
OPENSSL_CONF
is set to a proper configuration file,
e.g. the example configuration file
openssl/apps/openssl.cnf will do.
To create a time stamp request for design1.txt with SHA-1 without nonce and policy and no certificate is required in the response:
$ openssl ts -query -data design1.txt -no_nonce \ -out design1.tsq
To create a similar time stamp request but specifying the message imprint explicitly:
$ openssl ts -query \ -digest b7e5d3f93198b38379852f2c04e78d73abdd0f4b \ -no_nonce -out design1.tsq
To print the content of the previous request in human readable format:
$ openssl ts -query -in design1.tsq -text
To create a time stamp request which includes the MD5 digest of design2.txt, requests the signer certificate and nonce, specifies a policy ID (assuming the tsa_policy1 name is defined in the OID section of the config file):
$ openssl ts -query -data design2.txt -md5 \ -policy tsa_policy1 -cert -out design2.tsq
Before generating a response, a signing certificate must be
created for the TSA that contains the timeStamping
critical extended key usage extension without any other key usage
extensions. You can add the “extendedKeyUsage =
critical,timeStamping” line to the user certificate section of the
config file to generate a proper certificate. See the
req
, ca
, and
x509
commands for instructions. The examples below
assume that cacert.pem contains the certificate of the CA, tsacert.pem is
the signing certificate issued by cacert.pem and tsakey.pem is the private
key of the TSA.
To create a time stamp response for a request:
$ openssl ts -reply -queryfile design1.tsq -inkey tsakey.pem \ -signer tsacert.pem -out design1.tsr
If you want to use the settings in the config file you could just write:
$ openssl ts -reply -queryfile design1.tsq -out design1.tsr
To print a time stamp reply to stdout in human readable format:
$ openssl ts -reply -in design1.tsr -text
To create a time stamp token instead of time stamp response:
$ openssl ts -reply -queryfile design1.tsq \ -out design1_token.der -token_out
To print a time stamp token to stdout in human readable format:
$ openssl ts -reply -in design1_token.der -token_in \ -text -token_out
To extract the time stamp token from a response:
$ openssl ts -reply -in design1.tsr -out design1_token.der \ -token_out
To add “granted” status info to a time stamp token thereby creating a valid response:
$ openssl ts -reply -in design1_token.der \ -token_in -out design1.tsr
To verify a time stamp reply against a request:
$ openssl ts -verify -queryfile design1.tsq -in design1.tsr \ -CAfile cacert.pem -untrusted tsacert.pem
To verify a time stamp reply that includes the certificate chain:
$ openssl ts -verify -queryfile design2.tsq -in design2.tsr \ -CAfile cacert.pem
To verify a time stamp token against the original data file:
$ openssl ts -verify -data design2.txt -in design2.tsr \ -CAfile cacert.pem
To verify a time stamp token against a message imprint:
$ openssl ts -verify \ -digest b7e5d3f93198b38379852f2c04e78d73abdd0f4b \ -in design2.tsr -CAfile cacert.pem
TS BUGS
No support for time stamps over SMTP, though it is quite easy to implement an automatic email-based TSA with procmail and perl(1). Pure TCP/IP is not supported.
The file containing the last serial number of the TSA is not
locked when being read or written. This is a problem if more than one
instance of OpenSSL
is trying to create a time stamp
response at the same time.
Look for the FIXME word in the source files.
The source code should really be reviewed by somebody else, too.
More testing is needed.
TS AUTHORS
Zoltan Glozik <zglozik@opentsa.org>, OpenTSA project (http://www.opentsa.org).
SPKAC
openssl spkac |
[-challenge string]
[-in file]
[-key keyfile]
[-noout ]
[-out file]
[-passin arg]
[-pubkey ]
[-spkac spkacname]
[-spksect section]
[-verify ] |
The spkac
command processes Netscape
signed public key and challenge (SPKAC) files. It can print out their
contents, verify the signature, and produce its own SPKACs from a supplied
private key.
The options are as follows:
-challenge
string- Specifies the challenge string if an SPKAC is being created.
-in
file- This specifies the input file to read from, or
standard input if this option is not specified. Ignored if the
-key
option is used. -key
keyfile- Create an SPKAC file using the private key in
keyfile. The
-in
,-noout
,-spksect
, and-verify
options are ignored if present. -noout
- Don't output the text version of the SPKAC (not used if an SPKAC is being created).
-out
file- Specifies the output file to write to, or standard output by default.
-passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubkey
- Output the public key of an SPKAC (not used if an SPKAC is being created).
-spkac
spkacname- Allows an alternative name for the variable containing the SPKAC. The default is "SPKAC". This option affects both generated and input SPKAC files.
-spksect
section- Allows an alternative name for the section containing the SPKAC. The default is the default section.
-verify
- Verifies the digital signature on the supplied SPKAC.
SPKAC EXAMPLES
Print out the contents of an SPKAC:
$ openssl spkac -in
spkac.cnf
Verify the signature of an SPKAC:
$ openssl spkac -in spkac.cnf -noout
-verify
Create an SPKAC using the challenge string "hello":
$ openssl spkac -key key.pem
-challenge hello -out spkac.cnf
Example of an SPKAC, (long lines split up for clarity):
SPKAC=MIG5MGUwXDANBgkqhkiG9w0BAQEFAANLADBIAkEA1cCoq2Wa3Ixs47uI7F\ PVwHVIPDx5yso105Y6zpozam135a8R0CpoRvkkigIyXfcCjiVi5oWk+6FfPaD03u\ PFoQIDAQABFgVoZWxsbzANBgkqhkiG9w0BAQQFAANBAFpQtY/FojdwkJh1bEIYuc\ 2EeM2KHTWPEepWYeawvHD0gQ3DngSC75YCWnnDdq+NQ3F+X4deMx9AaEglZtULwV\ 4=
SPKAC NOTES
A created SPKAC with suitable DN components appended can be fed
into the ca
utility.
SPKACs are typically generated by Netscape when a form is submitted containing the KEYGEN tag as part of the certificate enrollment process.
The challenge string permits a primitive form of proof of possession of private key. By checking the SPKAC signature and a random challenge string, some guarantee is given that the user knows the private key corresponding to the public key being certified. This is important in some applications. Without this it is possible for a previous SPKAC to be used in a "replay attack".
VERIFY
openssl verify |
[-CAfile file]
[-CApath directory]
[-check_ss_sig ]
[-crl_check ]
[-crl_check_all ]
[-explicit_policy ]
[-extended_crl ] [-help ]
[-ignore_critical ]
[-inhibit_any ]
[-inhibit_map ]
[-issuer_checks ]
[-policy_check ]
[-purpose purpose]
[-untrusted file]
[-verbose ] [-x509_strict ]
[- ] [certificates] |
The verify
command verifies certificate
chains.
The options are as follows:
-check_ss_sig
- Verify the signature on the self-signed root CA. This is disabled by default because it doesn't add any security.
-CAfile
file- A file of trusted certificates. The file should contain multiple certificates in PEM format, concatenated together.
-CApath
directory- A directory of trusted certificates. The
certificates should have names of the form
hash.0,
or have symbolic links to them of this form ("hash" is the
hashed certificate subject name: see the
-hash
option of thex509
utility). Thec_rehash
script distributed with OpenSSL will automatically create symbolic links to a directory of certificates. -crl_check
- Checks end entity certificate validity by attempting to look up a valid CRL. If a valid CRL cannot be found an error occurs.
-crl_check_all
- Checks the validity of all certificates in the chain by attempting to look up valid CRLs.
-explicit_policy
- Set policy variable require-explicit-policy (see RFC 3280 et al).
-extended_crl
- Enable extended CRL features such as indirect CRLs and alternate CRL signing keys.
-help
- Prints out a usage message.
-ignore_critical
- Normally if an unhandled critical extension is present which is not
supported by
OpenSSL
, the certificate is rejected (as required by RFC 3280 et al). If this option is set, critical extensions are ignored. -inhibit_any
- Set policy variable inhibit-any-policy (see RFC 3280 et al).
-inhibit_map
- Set policy variable inhibit-policy-mapping (see RFC 3280 et al).
-issuer_checks
- Print out diagnostics relating to searches for the issuer certificate of the current certificate. This shows why each candidate issuer certificate was rejected. However the presence of rejection messages does not itself imply that anything is wrong: during the normal verify process several rejections may take place.
-policy_check
- Enables certificate policy processing.
-purpose
purpose- The intended use for the certificate. Without this option no chain verification will be done. Currently accepted uses are sslclient, sslserver, nssslserver, smimesign, smimeencrypt, crlsign, any, and ocsphelper. See the VERIFY OPERATION section for more information.
-untrusted
file- A file of untrusted certificates. The file should contain multiple certificates.
-verbose
- Print extra information about the operations being performed.
-x509_strict
- Disable workarounds for broken certificates which have to be disabled for strict X.509 compliance.
-
- Marks the last option. All arguments following this are assumed to be certificate files. This is useful if the first certificate filename begins with a ‘-’.
- certificates
- One or more certificates to verify. If no certificate files are included, an attempt is made to read a certificate from standard input. They should all be in PEM format.
VERIFY OPERATION
The verify
program uses the same functions
as the internal SSL and S/MIME verification, therefore this description
applies to these verify operations too.
There is one crucial difference between the verify operations
performed by the verify
program: wherever possible
an attempt is made to continue after an error, whereas normally the verify
operation would halt on the first error. This allows all the problems with a
certificate chain to be determined.
The verify operation consists of a number of separate steps:
Firstly a certificate chain is built up starting from the supplied certificate and ending in the root CA. It is an error if the whole chain cannot be built up. The chain is built up by looking up the issuer's certificate of the current certificate. If a certificate is found which is its own issuer, it is assumed to be the root CA.
The process of "looking up the issuer's certificate"
itself involves a number of steps. In versions of
OpenSSL
before 0.9.5a the first certificate whose
subject name matched the issuer of the current certificate was assumed to be
the issuer's certificate. In OpenSSL
0.9.6 and later
all certificates whose subject name matches the issuer name of the current
certificate are subject to further tests. The relevant authority key
identifier components of the current certificate (if present) must match the
subject key identifier (if present) and issuer and serial number of the
candidate issuer; in addition the keyUsage extension of
the candidate issuer (if present) must permit certificate signing.
The lookup first looks in the list of untrusted certificates and if no match is found the remaining lookups are from the trusted certificates. The root CA is always looked up in the trusted certificate list: if the certificate to verify is a root certificate, then an exact match must be found in the trusted list.
The second operation is to check every untrusted certificate's
extensions for consistency with the supplied purpose. If the
-purpose
option is not included, then no checks are
done. The supplied or "leaf" certificate must have extensions
compatible with the supplied purpose and all other certificates must also be
valid CA certificates. The precise extensions required are described in more
detail in the X.509
CERTIFICATE EXTENSIONS section below.
The third operation is to check the trust settings on the root CA.
The root CA should be trusted for the supplied purpose. For compatibility
with previous versions of SSLeay
and
OpenSSL
, a certificate with no trust settings is
considered to be valid for all purposes.
The final operation is to check the validity of the certificate chain. The validity period is checked against the current system time and the notBefore and notAfter dates in the certificate. The certificate signatures are also checked at this point.
If all operations complete successfully, the certificate is considered valid. If any operation fails then the certificate is not valid.
VERIFY DIAGNOSTICS
When a verify operation fails, the output messages can be somewhat cryptic. The general form of the error message is:
server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024-bit) error 24 at 1 depth lookup:invalid CA certificate
The first line contains the name of the certificate being verified, followed by the subject name of the certificate. The second line contains the error number and the depth. The depth is the number of the certificate being verified when a problem was detected starting with zero for the certificate being verified itself, then 1 for the CA that signed the certificate and so on. Finally a text version of the error number is presented.
An exhaustive list of the error codes and messages is shown below;
this also includes the name of the error code as defined in the header file
<openssl/x509_vfy.h>
. Some
of the error codes are defined but never returned: these are described as
"unused".
- 0 X509_V_OK: ok
- The operation was successful.
- 2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate
- The issuer certificate could not be found: this occurs if the issuer certificate of an untrusted certificate cannot be found.
- 3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL
- The CRL of a certificate could not be found.
- 4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature
- The certificate signature could not be decrypted. This means that the actual signature value could not be determined rather than it not matching the expected value. This is only meaningful for RSA keys.
- 5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature
- The CRL signature could not be decrypted: this means that the actual signature value could not be determined rather than it not matching the expected value. Unused.
- 6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key
- The public key in the certificate SubjectPublicKeyInfo could not be read.
- 7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure
- The signature of the certificate is invalid.
- 8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure
- The signature of the certificate is invalid.
- 9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid
- The certificate is not yet valid: the notBefore date is after the current time.
- 10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired
- The certificate has expired; that is, the notAfter date is before the current time.
- 11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid
- The CRL is not yet valid.
- 12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired
- The CRL has expired.
- 13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field
- The certificate notBefore field contains an invalid time.
- 14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field
- The certificate notAfter field contains an invalid time.
- 15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field
- The CRL lastUpdate field contains an invalid time.
- 16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field
- The CRL nextUpdate field contains an invalid time.
- 17 X509_V_ERR_OUT_OF_MEM: out of memory
- An error occurred trying to allocate memory. This should never happen.
- 18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate
- The passed certificate is self-signed and the same certificate cannot be found in the list of trusted certificates.
- 19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain
- The certificate chain could be built up using the untrusted certificates but the root could not be found locally.
- 20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate
- The issuer certificate of a locally looked up certificate could not be found. This normally means the list of trusted certificates is not complete.
- 21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate
- No signatures could be verified because the chain contains only one certificate and it is not self-signed.
- 22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long
- The certificate chain length is greater than the supplied maximum depth. Unused.
- 23 X509_V_ERR_CERT_REVOKED: certificate revoked
- The certificate has been revoked.
- 24 X509_V_ERR_INVALID_CA: invalid CA certificate
- A CA certificate is invalid. Either it is not a CA or its extensions are not consistent with the supplied purpose.
- 25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded
- The basicConstraints pathlength parameter has been exceeded.
- 26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose
- The supplied certificate cannot be used for the specified purpose.
- 27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted
- The root CA is not marked as trusted for the specified purpose.
- 28 X509_V_ERR_CERT_REJECTED: certificate rejected
- The root CA is marked to reject the specified purpose.
- 29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch
- The current candidate issuer certificate was rejected because its subject
name did not match the issuer name of the current certificate. Only
displayed when the
-issuer_checks
option is set. - 30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch
- The current candidate issuer certificate was rejected because its subject
key identifier was present and did not match the authority key identifier
current certificate. Only displayed when the
-issuer_checks
option is set. - 31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch
- The current candidate issuer certificate was rejected because its issuer
name and serial number were present and did not match the authority key
identifier of the current certificate. Only displayed when the
-issuer_checks
option is set. - 32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing
- The current candidate issuer certificate was rejected because its keyUsage extension does not permit certificate signing.
- 50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure
- An application specific error. Unused.
VERIFY BUGS
Although the issuer checks are a considerable improvement over the
old technique, they still suffer from limitations in the underlying
X509_LOOKUP API. One consequence of this is that trusted certificates with
matching subject name must either appear in a file (as specified by the
-CAfile
option) or a directory (as specified by
-CApath
). If they occur in both, only the
certificates in the file will be recognised.
Previous versions of OpenSSL
assumed
certificates with matching subject name were identical and mishandled
them.
VERSION
openssl version
[-abdfopv
]
The version
command is used to print out
version information about OpenSSL
.
The options are as follows:
-a
- All information: this is the same as setting all the other flags.
-b
- The date the current version of
OpenSSL
was built. -d
OPENSSLDIR
setting.-f
- Compilation flags.
-o
- Option information: various options set when the library was built.
-p
- Platform setting.
-v
- The current
OpenSSL
version.
VERSION NOTES
The output of openssl version -a
would
typically be used when sending in a bug report.
VERSION HISTORY
The -d
option was added in
OpenSSL
0.9.7.
X509
openssl x509 |
[-C ]
[-addreject arg]
[-addtrust arg]
[-alias ]
[-CA file]
[-CAcreateserial ]
[-CAform DER | PEM]
[-CAkey file]
[-CAkeyform DER | PEM]
[-CAserial file]
[-certopt option]
[-checkend arg]
[-clrext ] [-clrreject ]
[-clrtrust ] [-dates ]
[-days arg]
[-email ] [-enddate ]
[-extensions section]
[-extfile file]
[-fingerprint ] [-hash ]
[-in file]
[-inform DER | NET | PEM]
[-issuer ] [-issuer_hash ]
[-issuer_hash_old ]
[-keyform DER | PEM]
[-md5 | -sha1 ]
[-modulus ]
[-nameopt option]
[-noout ] [-ocsp_uri ]
[-ocspid ]
[-out file]
[-outform DER | NET | PEM]
[-passin arg]
[-pubkey ] [-purpose ]
[-req ] [-serial ]
[-set_serial n]
[-setalias arg]
[-signkey file]
[-startdate ] [-subject ]
[-subject_hash ]
[-subject_hash_old ]
[-text ] [-trustout ]
[-x509toreq ] |
The x509
command is a multi-purpose
certificate utility. It can be used to display certificate information,
convert certificates to various forms, sign certificate requests like a
"mini CA", or edit certificate trust settings.
Since there are a large number of options, they are split up into various sections.
X509 INPUT, OUTPUT, AND GENERAL PURPOSE OPTIONS
-in
file- This specifies the input file to read a certificate from, or standard input if this option is not specified.
-inform
DER | NET | PEM- This specifies the input format. Normally, the command will expect an
X.509 certificate, but this can change if other options such as
-req
are present. The DER format is the DER encoding of the certificate and PEM is the base64 encoding of the DER encoding with header and footer lines added. The NET option is an obscure Netscape server format that is now obsolete. -md5
|-sha1
- The digest to use. This affects any signing or display option that uses a
message digest, such as the
-fingerprint
,-signkey
, and-CA
options. If not specified, MD5 is used. If the key being used to sign with is a DSA key, this option has no effect: SHA1 is always used with DSA keys. -out
file- This specifies the output file to write to, or standard output by default.
-outform
DER | NET | PEM- This specifies the output format; the options have the same meaning as the
-inform
option. -passin
arg- The key password source. For more information about the format of arg, see the PASS PHRASE ARGUMENTS section above.
X509 DISPLAY OPTIONS
Note: The -alias
and
-purpose
options are also display options but are
described in the X509 TRUST
SETTINGS section.
-C
- This outputs the certificate in the form of a C source file.
-certopt
option- Customise the output format used with
-text
. The option argument can be a single option or multiple options separated by commas. The-certopt
switch may also be used more than once to set multiple options. See the X509 TEXT OPTIONS section for more information. -dates
- Prints out the start and expiry dates of a certificate.
-email
- Outputs the email address(es), if any.
-enddate
- Prints out the expiry date of the certificate; that is, the notAfter date.
-fingerprint
- Prints out the digest of the DER-encoded version of the whole certificate (see DIGEST OPTIONS).
-hash
- A synonym for
-subject_hash
, for backwards compatibility. -issuer
- Outputs the issuer name.
-issuer_hash
- Outputs the "hash" of the certificate issuer name.
-issuer_hash_old
- Outputs the "hash" of the certificate issuer name using the
older algorithm as used by
OpenSSL
versions before 1.0.0. -modulus
- This option prints out the value of the modulus of the public key contained in the certificate.
-nameopt
option- Option which determines how the subject or issuer names are displayed. The
option argument can be a single option or multiple
options separated by commas. Alternatively, the
-nameopt
switch may be used more than once to set multiple options. See the X509 NAME OPTIONS section for more information. -noout
- This option prevents output of the encoded version of the request.
-ocsp_uri
- Outputs the OCSP responder addresses, if any.
-ocspid
- Print OCSP hash values for the subject name and public key.
-pubkey
- Output the public key.
-serial
- Outputs the certificate serial number.
-startdate
- Prints out the start date of the certificate; that is, the notBefore date.
-subject
- Outputs the subject name.
-subject_hash
- Outputs the "hash" of the certificate subject name. This is used
in
OpenSSL
to form an index to allow certificates in a directory to be looked up by subject name. -subject_hash_old
- Outputs the "hash" of the certificate subject name using the
older algorithm as used by
OpenSSL
versions before 1.0.0. -text
- Prints out the certificate in text form. Full details are output including the public key, signature algorithms, issuer and subject names, serial number, any extensions present, and any trust settings.
X509 TRUST SETTINGS
Please note these options are currently experimental and may well change.
A trusted certificate is an ordinary certificate which has several additional pieces of information attached to it such as the permitted and prohibited uses of the certificate and an "alias".
Normally, when a certificate is being verified at least one certificate must be "trusted". By default, a trusted certificate must be stored locally and must be a root CA: any certificate chain ending in this CA is then usable for any purpose.
Trust settings currently are only used with a root CA. They allow a finer control over the purposes the root CA can be used for. For example, a CA may be trusted for an SSL client but not for SSL server use.
See the description of the verify
utility
for more information on the meaning of trust settings.
Future versions of OpenSSL
will recognize
trust settings on any certificate: not just root CAs.
-addreject
arg- Adds a prohibited use. It accepts the same values as the
-addtrust
option. -addtrust
arg- Adds a trusted certificate use. Any object name can be used here, but
currently only clientAuth (SSL client use),
serverAuth (SSL server use), and
emailProtection (S/MIME email) are used. Other
OpenSSL
applications may define additional uses. -alias
- Outputs the certificate alias, if any.
-clrreject
- Clears all the prohibited or rejected uses of the certificate.
-clrtrust
- Clears all the permitted or trusted uses of the certificate.
-purpose
- This option performs tests on the certificate extensions and outputs the results. For a more complete description, see the X.509 CERTIFICATE EXTENSIONS section.
-setalias
arg- Sets the alias of the certificate. This will allow the certificate to be referred to using a nickname, for example "Steve's Certificate".
-trustout
- This causes
x509
to output a trusted certificate. An ordinary or trusted certificate can be input, but by default an ordinary certificate is output and any trust settings are discarded. With the-trustout
option a trusted certificate is output. A trusted certificate is automatically output if any trust settings are modified.
X509 SIGNING OPTIONS
The x509
utility can be used to sign
certificates and requests: it can thus behave like a "mini
CA".
-CA
file- Specifies the CA certificate to be used for signing. When this option is
present,
x509
behaves like a "mini CA". The input file is signed by the CA using this option; that is, its issuer name is set to the subject name of the CA and it is digitally signed using the CA's private key.This option is normally combined with the
-req
option. Without the-req
option, the input is a certificate which must be self-signed. -CAcreateserial
- With this option the CA serial number file is created if it does not
exist: it will contain the serial number ‘02’ and the
certificate being signed will have ‘1’ as its serial number.
Normally, if the
-CA
option is specified and the serial number file does not exist, it is an error. -CAform
DER | PEM- The format of the CA certificate file. The default is PEM.
-CAkey
file- Sets the CA private key to sign a certificate with. If this option is not specified, it is assumed that the CA private key is present in the CA certificate file.
-CAkeyform
DER | PEM- The format of the CA private key. The default is PEM.
-CAserial
file- Sets the CA serial number file to use.
When the
-CA
option is used to sign a certificate, it uses a serial number specified in a file. This file consists of one line containing an even number of hex digits with the serial number to use. After each use the serial number is incremented and written out to the file again.The default filename consists of the CA certificate file base name with .srl appended. For example, if the CA certificate file is called mycacert.pem, it expects to find a serial number file called mycacert.srl.
-checkend
arg- Check whether the certificate expires in the next arg seconds. If so, exit with return value 1; otherwise exit with return value 0.
-clrext
- Delete any extensions from a certificate. This option is used when a
certificate is being created from another certificate (for example with
the
-signkey
or the-CA
options). Normally, all extensions are retained. -days
arg- Specifies the number of days to make a certificate valid for. The default is 30 days.
-extensions
section- The section to add certificate extensions from. If this option is not specified, the extensions should either be contained in the unnamed (default) section or the default section should contain a variable called "extensions" which contains the section to use.
-extfile
file- File containing certificate extensions to use. If not specified, no extensions are added to the certificate.
-keyform
DER | PEM- Specifies the format (DER or PEM) of the private key file used in the
-signkey
option. -req
- By default, a certificate is expected on input. With this option a certificate request is expected instead.
-set_serial
n- Specifies the serial number to use. This option can be used with either
the
-signkey
or-CA
options. If used in conjunction with the-CA
option, the serial number file (as specified by the-CAserial
or-CAcreateserial
options) is not used.The serial number can be decimal or hex (if preceded by ‘0x’). Negative serial numbers can also be specified but their use is not recommended.
-signkey
file- This option causes the input file to be self-signed using the supplied
private key.
If the input file is a certificate, it sets the issuer name to the subject name (i.e. makes it self-signed), changes the public key to the supplied value, and changes the start and end dates. The start date is set to the current time and the end date is set to a value determined by the
-days
option. Any certificate extensions are retained unless the-clrext
option is supplied.If the input is a certificate request, a self-signed certificate is created using the supplied private key using the subject name in the request.
-x509toreq
- Converts a certificate into a certificate request. The
-signkey
option is used to pass the required private key.
X509 NAME OPTIONS
The -nameopt
command line switch
determines how the subject and issuer names are displayed. If no
-nameopt
switch is present, the default
"oneline" format is used which is compatible with previous
versions of OpenSSL
. Each option is described in
detail below; all options can be preceded by a ‘-’ to turn the
option off. Only compat,
RFC2253, oneline, and
multiline will normally be used.
- align
- Align field values for a more readable output. Only usable with sep_multiline.
- compat
- Use the old format. This is equivalent to specifying no name options at all.
- dn_rev
- Reverse the fields of the DN. This is required by RFC 2253. As a side effect, this also reverses the order of multiple AVAs but this is permissible.
- dump_all
- Dump all fields. This option, when used with dump_der, allows the DER encoding of the structure to be unambiguously determined.
- dump_der
- When this option is set, any fields that need to be hexdumped will be dumped using the DER encoding of the field. Otherwise just the content octets will be displayed. Both options use the RFC 2253 #XXXX... format.
- dump_nostr
- Dump non-character string types (for example OCTET STRING); if this option is not set, non-character string types will be displayed as though each content octet represents a single character.
- dump_unknown
- Dump any field whose OID is not recognised by
OpenSSL
. - esc_2253
- Escape the "special" characters required by RFC 2253 in a field that is “ ,+"<>;”. Additionally, ‘#’ is escaped at the beginning of a string and a space character at the beginning or end of a string.
- esc_ctrl
- Escape control characters. That is, those with ASCII values less than 0x20 (space) and the delete (0x7f) character. They are escaped using the RFC 2253 \XX notation (where XX are two hex digits representing the character value).
- esc_msb
- Escape characters with the MSB set; that is, with ASCII values larger than 127.
- multiline
- A multiline format. It is equivalent to esc_ctrl, esc_msb, sep_multiline, space_eq, lname, and align.
- no_type
- This option does not attempt to interpret multibyte characters in any way. That is, their content octets are merely dumped as though one octet represents each character. This is useful for diagnostic purposes but will result in rather odd looking output.
- nofname, sname, lname, oid
- These options alter how the field name is displayed. nofname does not display the field at all. sname uses the "short name" form (CN for commonName, for example). lname uses the long form. oid represents the OID in numerical form and is useful for diagnostic purpose.
- oneline
- A oneline format which is more readable than RFC2253. It is equivalent to specifying the esc_2253, esc_ctrl, esc_msb, utf8, dump_nostr, dump_der, use_quote, sep_comma_plus_spc, space_eq, and sname options.
- RFC2253
- Displays names compatible with RFC 2253; equivalent to esc_2253, esc_ctrl, esc_msb, utf8, dump_nostr, dump_unknown, dump_der, sep_comma_plus, dn_rev, and sname.
- sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space, sep_multiline
- These options determine the field separators. The first character is between RDNs and the second between multiple AVAs (multiple AVAs are very rare and their use is discouraged). The options ending in "space" additionally place a space after the separator to make it more readable. The sep_multiline uses a linefeed character for the RDN separator and a spaced ‘+’ for the AVA separator. It also indents the fields by four characters.
- show_type
- Show the type of the ASN1 character string. The type precedes the field contents. For example "BMPSTRING: Hello World".
- space_eq
- Places spaces round the ‘=’ character which follows the field name.
- use_quote
- Escapes some characters by surrounding the whole string with ‘"’ characters. Without the option, all escaping is done with the ‘\’ character.
- utf8
- Convert all strings to UTF8 format first. This is required by RFC 2253. If you are lucky enough to have a UTF8 compatible terminal, the use of this option (and not setting esc_msb) may result in the correct display of multibyte (international) characters. If this option is not present, multibyte characters larger than 0xff will be represented using the format \UXXXX for 16 bits and \WXXXXXXXX for 32 bits. Also, if this option is off, any UTF8Strings will be converted to their character form first.
X509 TEXT OPTIONS
As well as customising the name output format, it is also possible
to customise the actual fields printed using the
-certopt
options when the
-text
option is present. The default behaviour is to
print all fields.
- ca_default
- The value used by the
ca
utility; equivalent to no_issuer, no_pubkey, no_header, no_version, no_sigdump, and no_signame. - compatible
- Use the old format. This is equivalent to specifying no output options at all.
- ext_default
- Retain default extension behaviour: attempt to print out unsupported certificate extensions.
- ext_dump
- Hex dump unsupported extensions.
- ext_error
- Print an error message for unsupported certificate extensions.
- ext_parse
- ASN1 parse unsupported extensions.
- no_aux
- Don't print out certificate trust information.
- no_extensions
- Don't print out any X509V3 extensions.
- no_header
- Don't print header information: that is, the lines saying "Certificate" and "Data".
- no_issuer
- Don't print out the issuer name.
- no_pubkey
- Don't print out the public key.
- no_serial
- Don't print out the serial number.
- no_sigdump
- Don't give a hexadecimal dump of the certificate signature.
- no_signame
- Don't print out the signature algorithm used.
- no_subject
- Don't print out the subject name.
- no_validity
- Don't print the validity; that is, the notBefore and notAfter fields.
- no_version
- Don't print out the version number.
X509 EXAMPLES
Display the contents of a certificate:
$ openssl x509 -in cert.pem -noout
-text
Display the certificate serial number:
$ openssl x509 -in cert.pem -noout
-serial
Display the certificate subject name:
$ openssl x509 -in cert.pem -noout
-subject
Display the certificate subject name in RFC 2253 form:
$ openssl x509 -in cert.pem -noout
-subject -nameopt RFC2253
Display the certificate subject name in oneline form on a terminal supporting UTF8:
$ openssl x509 -in cert.pem -noout -subject \ -nameopt oneline,-esc_msb
Display the certificate MD5 fingerprint:
$ openssl x509 -in cert.pem -noout
-fingerprint
Display the certificate SHA1 fingerprint:
$ openssl x509 -sha1 -in cert.pem
-noout -fingerprint
Convert a certificate from PEM to DER format:
$ openssl x509 -in cert.pem -inform
PEM -out cert.der -outform DER
Convert a certificate to a certificate request:
$ openssl x509 -x509toreq -in cert.pem -out req.pem \ -signkey key.pem
Convert a certificate request into a self-signed certificate using extensions for a CA:
$ openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions \ v3_ca -signkey key.pem -out cacert.pem
Sign a certificate request using the CA certificate above and add user certificate extensions:
$ openssl x509 -req -in req.pem -extfile openssl.cnf -extensions \ v3_usr -CA cacert.pem -CAkey key.pem -CAcreateserial
Set a certificate to be trusted for SSL client use and set its alias to "Steve's Class 1 CA":
$ openssl x509 -in cert.pem -addtrust clientAuth \ -setalias "Steve's Class 1 CA" -out trust.pem
X509 NOTES
The PEM format uses the header and footer lines:
-----BEGIN CERTIFICATE----- -----END CERTIFICATE-----
It will also handle files containing:
-----BEGIN X509 CERTIFICATE----- -----END X509 CERTIFICATE-----
Trusted certificates have the lines:
-----BEGIN TRUSTED CERTIFICATE----- -----END TRUSTED CERTIFICATE-----
The conversion to UTF8 format used with the name options assumes that T61Strings use the ISO 8859-1 character set. This is wrong, but Netscape and MSIE do this, as do many certificates. So although this is incorrect it is more likely to display the majority of certificates correctly.
The -fingerprint
option takes the digest
of the DER-encoded certificate. This is commonly called a
"fingerprint". Because of the nature of message digests, the
fingerprint of a certificate is unique to that certificate and two
certificates with the same fingerprint can be considered to be the same.
The Netscape fingerprint uses MD5, whereas MSIE uses SHA1.
The -email
option searches the subject
name and the subject alternative name extension. Only unique email addresses
will be printed out: it will not print the same address more than once.
X.509 CERTIFICATE EXTENSIONS
The -purpose
option checks the certificate
extensions and determines what the certificate can be used for. The actual
checks done are rather complex and include various hacks and workarounds to
handle broken certificates and software.
The same code is used when verifying untrusted certificates in chains, so this section is useful if a chain is rejected by the verify code.
The basicConstraints extension CA flag is used to determine whether the certificate can be used as a CA. If the CA flag is true, it is a CA; if the CA flag is false, it is not a CA. All CAs should have the CA flag set to true.
If the basicConstraints extension is absent, then the certificate is considered to be a "possible CA"; other extensions are checked according to the intended use of the certificate. A warning is given in this case because the certificate should really not be regarded as a CA: however, it is allowed to be a CA to work around some broken software.
If the certificate is a V1 certificate (and thus has no extensions) and it is self-signed, it is also assumed to be a CA but a warning is again given: this is to work around the problem of Verisign roots which are V1 self-signed certificates.
If the keyUsage extension is present, then additional restraints are made on the uses of the certificate. A CA certificate must have the keyCertSign bit set if the keyUsage extension is present.
The extended key usage extension places additional restrictions on the certificate uses. If this extension is present (whether critical or not), the key can only be used for the purposes specified.
A complete description of each test is given below. The comments about basicConstraints and keyUsage and V1 certificates above apply to all CA certificates.
- SSL Client
- The extended key usage extension must be absent or include the "web client authentication" OID. keyUsage must be absent or it must have the digitalSignature bit set. Netscape certificate type must be absent or it must have the SSL client bit set.
- SSL Client CA
- The extended key usage extension must be absent or include the "web client authentication" OID. Netscape certificate type must be absent or it must have the SSL CA bit set: this is used as a work around if the basicConstraints extension is absent.
- SSL Server
- The extended key usage extension must be absent or include the "web server authentication" and/or one of the SGC OIDs. keyUsage must be absent or it must have the digitalSignature set, the keyEncipherment set, or both bits set. Netscape certificate type must be absent or have the SSL server bit set.
- SSL Server CA
- The extended key usage extension must be absent or include the "web server authentication" and/or one of the SGC OIDs. Netscape certificate type must be absent or the SSL CA bit must be set: this is used as a work around if the basicConstraints extension is absent.
- Netscape SSL Server
- For Netscape SSL clients to connect to an SSL server; it must have the keyEncipherment bit set if the keyUsage extension is present. This isn't always valid because some cipher suites use the key for digital signing. Otherwise it is the same as a normal SSL server.
- Common S/MIME Client Tests
- The extended key usage extension must be absent or include the "email protection" OID. Netscape certificate type must be absent or should have the S/MIME bit set. If the S/MIME bit is not set in Netscape certificate type, then the SSL client bit is tolerated as an alternative but a warning is shown: this is because some Verisign certificates don't set the S/MIME bit.
- S/MIME Signing
- In addition to the common S/MIME client tests, the digitalSignature bit must be set if the keyUsage extension is present.
- S/MIME Encryption
- In addition to the common S/MIME tests, the keyEncipherment bit must be set if the keyUsage extension is present.
- S/MIME CA
- The extended key usage extension must be absent or include the "email protection" OID. Netscape certificate type must be absent or must have the S/MIME CA bit set: this is used as a work around if the basicConstraints extension is absent.
- CRL Signing
- The keyUsage extension must be absent or it must have the CRL signing bit set.
- CRL Signing CA
- The normal CA tests apply. Except in this case the basicConstraints extension must be present.
X509 BUGS
Extensions in certificates are not transferred to certificate requests and vice versa.
It is possible to produce invalid certificates or requests by specifying the wrong private key or using inconsistent options in some cases: these should be checked.
There should be options to explicitly set such things as start and end dates, rather than an offset from the current time.
The code to implement the verify behaviour described in the
X509 TRUST SETTINGS is
currently being developed. It thus describes the intended behaviour rather
than the current behaviour. It is hoped that it will represent reality in
OpenSSL
0.9.5 and later.
X509 HISTORY
Before OpenSSL
0.9.8, the default digest
for RSA keys was MD5.
The hash algorithm used in the
-subject_hash
and
-issuer_hash
options before
OpenSSL
1.0.0 was based on the deprecated MD5
algorithm and the encoding of the distinguished name. In
OpenSSL
1.0.0 and later it is based on a canonical
version of the DN using SHA1. This means that any directories using the old
form must have their links rebuilt using c_rehash or
similar.
FILES
- /etc/ssl/
- Default config directory for
openssl
. - /etc/ssl/lib/
- Unused.
- /etc/ssl/private/
- Default private key directory.
- /etc/ssl/openssl.cnf
- Default configuration file for
openssl
. - /etc/ssl/x509v3.cnf
- Default configuration file for
x509
certificates.
SEE ALSO
STANDARDS
The SSL Protocol, Netscape Communications Corp., February 1995.
The SSL 3.0 Protocol, Netscape Communications Corp., November 1996.
T. Dierks and C. Allen, The TLS Protocol Version 1.0, RFC 2246, January 1999.
M. Wahl, S. Killie, and T. Howes, Lightweight Directory Access Protocol (v3): UTF-8 String Representation of Distinguished Names, RFC 2253, December 1997.
B. Kaliski, PKCS #7: Cryptographic Message Syntax Version 1.5, RFC 2315, March 1998.
R. Housley, W. Ford, W. Polk, and D. Solo, Internet X.509 Public Key Infrastructure Certificate and CRL Profile, RFC 2459, January 1999.
M. Myers, R. Ankney, A. Malpani, S. Galperin, and C. Adams, X.509 Internet Public Key Infrastructure Online Certificate Status Protocol – OCSP, RFC 2560, June 1999.
R. Housley, Cryptographic Message Syntax, RFC 2630, June 1999.
P. Chown, Advanced Encryption Standard (AES) Ciphersuites for Transport Layer Security (TLS), RFC 3268, June 2002.
HISTORY
The
openssl(1) document appeared in OpenSSL
0.9.2. The list-
XXX-commands
pseudo-commands were added in OpenSSL
0.9.3; the
no-
XXX pseudo-commands were added in
OpenSSL
0.9.5a; the
list-
XXX-algorithms
pseudo-commands were added in OpenSSL
1.0.0.