NAME
CMS_get0_RecipientInfos
,
CMS_RecipientInfo_type
,
CMS_RecipientInfo_ktri_get0_signer_id
,
CMS_RecipientInfo_ktri_cert_cmp
,
CMS_RecipientInfo_set0_pkey
,
CMS_RecipientInfo_kekri_get0_id
,
CMS_RecipientInfo_kekri_id_cmp
,
CMS_RecipientInfo_set0_key
,
CMS_RecipientInfo_decrypt
,
CMS_RecipientInfo_encrypt
—
CMS EnvelopedData RecipientInfo
routines
SYNOPSIS
#include
<openssl/cms.h>
STACK_OF(CMS_RecipientInfo) *
CMS_get0_RecipientInfos
(CMS_ContentInfo
*cms);
int
CMS_RecipientInfo_type
(CMS_RecipientInfo
*ri);
int
CMS_RecipientInfo_ktri_get0_signer_id
(CMS_RecipientInfo
*ri, ASN1_OCTET_STRING **keyid,
X509_NAME **issuer, ASN1_INTEGER
**sno);
int
CMS_RecipientInfo_ktri_cert_cmp
(CMS_RecipientInfo
*ri, X509 *certificate);
int
CMS_RecipientInfo_set0_pkey
(CMS_RecipientInfo
*ri, EVP_PKEY *pkey);
int
CMS_RecipientInfo_kekri_get0_id
(CMS_RecipientInfo
*ri, X509_ALGOR **palg,
ASN1_OCTET_STRING **pid,
ASN1_GENERALIZEDTIME **pdate,
ASN1_OBJECT **potherid, ASN1_TYPE
**pothertype);
int
CMS_RecipientInfo_kekri_id_cmp
(CMS_RecipientInfo
*ri, const unsigned char *id,
size_t idlen);
int
CMS_RecipientInfo_set0_key
(CMS_RecipientInfo
*ri, unsigned char *key, size_t
keylen);
int
CMS_RecipientInfo_decrypt
(CMS_ContentInfo
*cms, CMS_RecipientInfo *ri);
int
CMS_RecipientInfo_encrypt
(CMS_ContentInfo
*cms, CMS_RecipientInfo *ri);
DESCRIPTION
CMS_get0_RecipientInfos
()
returns all the RecipientInfo structures associated
with the EnvelopedData structure
cms.
CMS_RecipientInfo_type
()
returns the type of ri:
CMS_RECIPINFO_TRANS |
for | KeyTransRecipientInfo, |
CMS_RECIPINFO_AGREE |
for | KeyAgreeRecipientInfo, |
CMS_RECIPINFO_KEK |
for | KEKRecipientInfo, |
CMS_RECIPINFO_PASS |
for | PasswordRecipientinfo, or |
CMS_RECIPINFO_OTHER |
for | OtherRecipientInfo. |
CMS_RecipientInfo_ktri_get0_signer_id
()
retrieves the certificate RecipientIdentifier
associated with the KeyTransRecipientInfo structure
ri. Either the
SubjectKeyIdentifier will be set in
keyid or both issuer name and serial number in
issuer and sno.
CMS_RecipientInfo_ktri_cert_cmp
()
compares the certificate against the
KeyTransRecipientInfo structure
ri.
CMS_RecipientInfo_set0_pkey
()
associates the private key pkey with the
KeyTransRecipientInfo structure
ri.
CMS_RecipientInfo_kekri_get0_id
()
retrieves the key information from the
KEKRecipientInfo structure ri.
Fields are copied out as follows:
keyEncryptionAlgorithm | to | *palg, |
keyIdentifier | to | *pid, |
date | to | *pdate (optional), |
other.keyAttrId | to | *potherid (optional), |
other.keyAttr | to | *pothertype (optional). |
NULL
is written to
the corresponding parameter. Parameters the application is not interested in
can be set to NULL
.
CMS_RecipientInfo_kekri_id_cmp
()
compares the identifier in the id and
idlen parameters against the
keyIdentifier field of the
KEKRecipientInfo structure
ri.
CMS_RecipientInfo_set0_key
()
associates the symmetric key of length
keylen with the KEKRecipientInfo
structure ri.
CMS_RecipientInfo_decrypt
()
attempts to decrypt the RecipientInfo structure
ri in cms. A key must have been
associated with ri first.
CMS_RecipientInfo_encrypt
()
attempts to encrypt the RecipientInfo structure
ri in cms. A key must have been
associated with ri first and the content encryption
key must be available, for example by a previous call to
CMS_RecipientInfo_decrypt
().
The main purpose of these functions is to enable an application to lookup recipient keys using any appropriate technique when the simpler method of CMS_decrypt(3) is not appropriate.
In typical usage, an application
retrieves all CMS_RecipientInfo structures using
CMS_get0_RecipientInfos
()
and checks the type of each using
CMS_RecipientInfo_type
(). Depending on the type, the
CMS_RecipientInfo structure can be ignored or its key
identifier data retrieved using an appropriate function. If the
corresponding secret or private key can be obtained by any appropriate means
it can then be associated with the structure and
CMS_RecipientInfo_decrypt
() called. If successful,
CMS_decrypt(3) can be called with a
NULL
key to decrypt the enveloped content.
The function
CMS_RecipientInfo_encrypt
()
can be used to add a new recipient to an existing enveloped data structure.
Typically an application will first decrypt an appropriate
CMS_RecipientInfo structure to make the content
encrypt key available. It will then add a new recipient using a function
such as
CMS_add1_recipient_cert(3) and finally encrypt the content
encryption key using
CMS_RecipientInfo_encrypt
().
RETURN VALUES
CMS_get0_RecipientInfos
() returns an
internal pointer to all the CMS_RecipientInfo
structures, or NULL
if an error occurs.
CMS_RecipientInfo_type
() returns an
integer constant.
CMS_RecipientInfo_ktri_get0_signer_id
(),
CMS_RecipientInfo_set0_pkey
(),
CMS_RecipientInfo_kekri_get0_id
(),
CMS_RecipientInfo_set0_key
(),
CMS_RecipientInfo_decrypt
(), and
CMS_RecipientInfo_encrypt
() return 1 for success or
0 if an error occurs.
CMS_RecipientInfo_ktri_cert_cmp
() and
CMS_RecipientInfo_kekri_id_cmp
() return 0 when
ri matches or non-zero otherwise.
Any error can be obtained from ERR_get_error(3).
SEE ALSO
STANDARDS
RFC 5652 Cryptographic Message Syntax (CMS):
- section 6.1: EnvelopedData Type
- section 6.2: RecipientInfo Type
- section 6.2.1: KeyTransRecipientInfo Type
- section 6.2.3: KEKRecipientInfo Type
HISTORY
These functions first appeared in OpenSSL 0.9.8h, except that
CMS_RecipientInfo_encrypt
() first appeared in
OpenSSL 1.0.2. They have been available since OpenBSD
6.7.