get or set certificate verification
*ctx, int s);
*ctx, int depth);
*ctx, X509 *cert);
*ctx, STACK_OF(X509) *chain);
const char *
Most of these functions are typically called after X509_verify_cert(3) to inspect status information related to certificate verification. Some may also be called in a verification callback to determine the nature of an error.
returns the error code of ctx. See the
CODES section for a full description of all error codes.
sets the error code of ctx to s.
For example it might be used in a verification callback to set an error
based on additional checks.
returns the depth of the error. This is a non-negative integer representing
where in the certificate chain the error occurred. If it is zero, it
occurred in the end entity certificate, one if it is the certificate which
signed the end entity certificate, and so on.
sets the error depth. This can be used in combination with
X509_STORE_CTX_set_error() to set the depth at which
an error condition was detected.
returns the certificate in ctx which caused the error
NULL if no certificate is relevant.
sets the certificate which caused the error in ctx to
the given cert. This value is not intended to remain
valid for very long, and remains owned by the caller. It may be examined by
a verification callback invoked to handle each error encountered during
chain verification and is no longer required after such a callback. If a
callback wishes the save the certificate for use after it returns, it needs
to increment its reference count via
X509_up_ref(3). Once such a saved certificate is no longer needed, it
can be freed with X509_free(3).
returns the certificate that caused issuer validation to fail or
NULL if no CA certificate is relevant.
returns the certificate revocation list that caused CRL checking to fail or
NULL if no CRL is relevant.
When, during certification
path validation, the need arises to check the validity of the certification
path of a CRL issuer certificate, the library creates a new, temporary
X509_STORE_CTX object. If
is called on that temporary object, a pointer to the original certification
path validation context is returned. This may be useful in callback
functions called from
X509_verify_cert(3) or from its subroutines to find out
whether the callback is called from the path validation of the target
certificate or from the path validation of a related CRL issuer certificate,
and if the latter, what the target certificate is.
returns an internal pointer to a complete validate chain if a previous call
to X509_verify_cert(3) was successful. If the call to
X509_verify_cert(3) was not successful, the returned chain
may be incomplete or invalid.
is a deprecated alias of
returns a deep copy of the same chain which persists even after the
ctx structure is freed. When it is no longer needed,
it should be freed using
frees the validate chain generated by if a previous call to
X509_verify_cert(3), if any, and replaces it with the given
chain. Ownership of the chain is
transferred to the ctx, so it should not be freed by
returns a human readable error string for verification error
The above functions should be used instead of directly referencing the fields in the X509_VERIFY_CTX structure.
In versions of OpenSSL
before 1.0, the current certificate returned by
NULL. Applications should check the return
value before printing out any debugging information relating to the current
If an unrecognised error code
is passed to
the numerical value of the unknown code is returned in a static buffer. This
is not thread safe but will never happen unless an invalid code is
X509_V_OK or an error code.
X509_STORE_CTX_get_error_depth() returns a
non-negative error depth.
X509_STORE_CTX_get0_current_crl() return the object
which caused the error or
NULL if no object of the
requested kind is relevant to the error.
the parent context or
ctx is not a temporary child context used for path
validation of a CRL issuer certificate.
the number of untrusted certificates that were used in building the chain
during a call to
X509_STORE_CTX_get1_chain() return a pointer to a
stack of certificates or
NULL if an error
an internal pointer to the valid_policy_tree created
by X509_policy_check(3) or
validation failed or the resulting tree was empty.
returns the *pexplicit_policy output argument of
X509_policy_check(3). If validation succeeded, it is 1 if
X509_V_FLAG_EXPLICIT_POLICY was requested or 0
X509_verify_cert_error_string() returns a
human readable error string for verification error
A list of error codes and messages is shown below. Some of the error codes are defined but currently never returned: these are described as "unused".
- The operation was successful.
X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get 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.
X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL
- The CRL of a certificate could not be found.
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.
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.
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.
X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure
- The signature of the certificate is invalid.
X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure
- The signature of the CRL is invalid.
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.
X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired
- The certificate has expired: that is the notAfter date is before the current time.
X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid
- The CRL is not yet valid.
X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired
- The CRL has expired.
X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field
- The certificate notBefore field contains an invalid time.
X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field
- The certificate notAfter field contains an invalid time.
X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field
- The CRL lastUpdate field contains an invalid time.
X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field
- The CRL nextUpdate field contains an invalid time.
X509_V_ERR_OUT_OF_MEM: out of memory
- An error occurred trying to allocate memory. This should never happen.
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.
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.
X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate
- The issuer certificate could not be found: this occurs if the issuer certificate of an untrusted certificate cannot be found.
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.
X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long
- The certificate chain length is greater than the supplied maximum depth. Unused.
X509_V_ERR_CERT_REVOKED: certificate revoked
- The certificate has been revoked.
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.
X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded
- The basicConstraints path-length parameter has been exceeded.
X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose
- The supplied certificate cannot be used for the specified purpose.
X509_V_ERR_CERT_UNTRUSTED: certificate not trusted
- The root CA is not marked as trusted for the specified purpose.
X509_V_ERR_CERT_REJECTED: certificate rejected
- The root CA is marked to reject the specified purpose.
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. This is only set if issuer check debugging is enabled; it is used for status notification and is not in itself an error.
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. This is only set if issuer check debugging is enabled; it is used for status notification and is not in itself an error.
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 was present and did not match the authority key identifier of the current certificate. This is only set if issuer check debugging is enabled; it is used for status notification and is not in itself an error.
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. This is only set if issuer check debugging is enabled it is used for status notification and is not in itself an error.
X509_V_ERR_INVALID_EXTENSION: invalid or inconsistent certificate extension
- A certificate extension had an invalid value (for example an incorrect encoding) or some value inconsistent with other extensions.
X509_V_ERR_INVALID_POLICY_EXTENSION: invalid or inconsistent certificate policy extension
- A certificate policies extension had an invalid value (for example an incorrect encoding) or some value inconsistent with other extensions. This error only occurs if policy processing is enabled.
X509_V_ERR_NO_EXPLICIT_POLICY: no explicit policy
- The verification flags were set to require an explicit policy but none was present.
X509_V_ERR_DIFFERENT_CRL_SCOPE: different CRL scope
- The only CRLs that could be found did not match the scope of the certificate.
X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE: unsupported extension feature
- Some feature of a certificate extension is not supported. Unused.
X509_V_ERR_PERMITTED_VIOLATION: permitted subtree violation
- A name constraint violation occurred in the permitted subtrees.
X509_V_ERR_EXCLUDED_VIOLATION: excluded subtree violation
- A name constraint violation occurred in the excluded subtrees.
X509_V_ERR_SUBTREE_MINMAX: name constraints minimum and maximum not supported
- A certificate name constraints extension included a minimum or maximum field: this is not supported.
RFC 3779 resource not subset of parent's resources
- When walking up a certificate chain, all resources specified in RFC 3779 extensions must be contained in the resources delegated in the issuer's RFC 3779 extensions. The error indicates that this is not the case or that the trust anchor has inheritance.
X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: unsupported name constraint type
- An unsupported name constraint type was encountered. OpenSSL currently only supports directory name, DNS name, email and URI types.
X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: unsupported or invalid name constraint syntax
- The format of the name constraint is not recognised: for example an email address format of a form not mentioned in RFC 3280. This could be caused by a garbage extension or some new feature not currently supported.
X509_V_ERR_CRL_PATH_VALIDATION_ERROR: CRL path validation error
- An error occurred when attempting to verify the CRL path. This error can only happen if extended CRL checking is enabled.
X509_V_ERR_APPLICATION_VERIFICATION: application verification failure
- An application specific error. This will never be returned unless explicitly set by an application.
X509_policy_check(3), X509_policy_tree_level_count(3), X509_STORE_CTX_new(3), X509_STORE_CTX_set_verify(3), X509_STORE_CTX_set_verify_cb(3), X509_STORE_set_verify_cb(3), X509_up_ref(3), X509_verify_cert(3)
X509_verify_cert_error_string() first appeared in
SSLeay 0.8.0 and have been available since OpenBSD
X509_STORE_CTX_get1_chain() first appeared
in OpenSSL 0.9.5 and has been available since OpenBSD
X509_STORE_CTX_get_explicit_policy() first appeared
in OpenSSL 0.9.8 and have been available since OpenBSD
X509_STORE_CTX_get0_parent_ctx() first appeared in
OpenSSL 1.0.0 and have been available since OpenBSD
X509_STORE_CTX_get0_chain() first appeared
in OpenSSL 1.1.0 and has been available since OpenBSD
X509_STORE_CTX_set0_verified_chain() first appeared
in OpenSSL 1.1.0 and have been available since OpenBSD