.\" $OpenBSD: X509_STORE_CTX_get_error.3,v 1.11 2018/03/27 17:35:50 schwarze Exp $
.\" full merge up to:
.\" OpenSSL crypto/X509_STORE_CTX_get_error f0e0fd51 Apr 14 23:59:26 2016 -0400
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.\" OpenSSL man3/X509_STORE_CTX_get_error 2947af32 Nov 19 00:10:05 2016 +0100
.\" OpenSSL man3/X509_STORE_CTX_new 7643a172 Apr 21 13:35:51 2017 +0200
.\"
.\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
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.Dd $Mdocdate: March 27 2018 $
.Dt X509_STORE_CTX_GET_ERROR 3
.Os
.Sh NAME
.Nm X509_STORE_CTX_get_error ,
.Nm X509_STORE_CTX_set_error ,
.Nm X509_STORE_CTX_get_error_depth ,
.Nm X509_STORE_CTX_get_current_cert ,
.Nm X509_STORE_CTX_get0_cert ,
.Nm X509_STORE_CTX_get0_chain ,
.Nm X509_STORE_CTX_get1_chain ,
.Nm X509_verify_cert_error_string
.Nd get or set certificate verification status information
.Sh SYNOPSIS
.In openssl/x509.h
.Ft int
.Fo X509_STORE_CTX_get_error
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft void
.Fo X509_STORE_CTX_set_error
.Fa "X509_STORE_CTX *ctx"
.Fa "int s"
.Fc
.Ft int
.Fo X509_STORE_CTX_get_error_depth
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft X509 *
.Fo X509_STORE_CTX_get_current_cert
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft X509 *
.Fo X509_STORE_CTX_get0_cert
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft STACK_OF(X509) *
.Fo X509_STORE_CTX_get0_chain
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft STACK_OF(X509) *
.Fo X509_STORE_CTX_get1_chain
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft const char *
.Fo X509_verify_cert_error_string
.Fa "long n"
.Fc
.Sh DESCRIPTION
These functions are typically called after
.Xr X509_verify_cert 3
has indicated an error or in a verification callback to determine the
nature of an error.
.Pp
.Fn X509_STORE_CTX_get_error
returns the error code of
.Fa ctx .
See the
.Sy ERROR CODES
section for a full description of all error codes.
.Pp
.Fn X509_STORE_CTX_set_error
sets the error code of
.Fa ctx
to
.Fa s .
For example it might be used in a verification callback to set an error
based on additional checks.
.Pp
.Fn X509_STORE_CTX_get_error_depth
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.
.Pp
.Fn X509_STORE_CTX_get_current_cert
returns the certificate in
.Fa ctx
which caused the error or
.Dv NULL
if no certificate is relevant.
.Pp
.Fn X509_STORE_CTX_get0_chain
returns an internal pointer to a complete validate chain
if a previous call to
.Xr X509_verify_cert 3
was successful.
If the call to
.Xr X509_verify_cert 3
was not successful, the returned chain may be incomplete or invalid.
.Fn X509_STORE_CTX_get1_chain
returns a deep copy of the same chain which persists even after the
.Fa ctx
structure is freed.
When it is no longer needed, it should be freed using
.Fn sk_X509_pop_free chain X509_free .
.Pp
.Fn X509_verify_cert_error_string
returns a human readable error string for verification error
.Fa n .
.Pp
The above functions should be used instead of directly referencing the
fields in the
.Sy X509_VERIFY_CTX
structure.
.Pp
In versions of OpenSSL before 1.0, the current certificate returned by
.Fn X509_STORE_CTX_get_current_cert
was never
.Dv NULL .
Applications should check the return value before printing out any
debugging information relating to the current certificate.
.Pp
If an unrecognised error code is passed to
.Fn X509_verify_cert_error_string ,
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
passed.
.Sh RETURN VALUES
.Fn X509_STORE_CTX_get_error
returns
.Dv X509_V_OK
or an error code.
.Pp
.Fn X509_STORE_CTX_get_error_depth
returns a non-negative error depth.
.Pp
.Fn X509_STORE_CTX_get_current_cert
returns the certificate which caused the error or
.Dv NULL
if no certificate is relevant to the error.
.Pp
.Fn X509_STORE_CTX_get0_cert
retrieves an internal pointer to the certificate being verified by
.Fa ctx .
.Pp
.Fn X509_STORE_CTX_get0_chain
and
.Fn X509_STORE_CTX_get1_chain
return a pointer to a stack of certificates or
.Dv NULL
if an error occurs.
.Pp
.Fn X509_verify_cert_error_string
returns a human readable error string for verification error
.Fa n .
.Sh ERROR CODES
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".
.Bl -tag -width Ds
.It Dv X509_V_OK : No ok
The operation was successful.
.It Dv X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT : \
 No 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.
.It Dv X509_V_ERR_UNABLE_TO_GET_CRL : No unable to get certificate CRL
The CRL of a certificate could not be found.
.It Dv X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE : \
 No 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.
.It Dv X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE : \
 No 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.
.It Dv X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY : \
 No unable to decode issuer public key
The public key in the certificate
.Vt SubjectPublicKeyInfo
could not be read.
.It Dv X509_V_ERR_CERT_SIGNATURE_FAILURE : No certificate signature failure
The signature of the certificate is invalid.
.It Dv X509_V_ERR_CRL_SIGNATURE_FAILURE : No CRL signature failure
The signature of the certificate is invalid.
.It Dv X509_V_ERR_CERT_NOT_YET_VALID : No certificate is not yet valid
The certificate is not yet valid: the notBefore date is after the
current time.
.It Dv X509_V_ERR_CERT_HAS_EXPIRED : No certificate has expired
The certificate has expired: that is the notAfter date is before the
current time.
.It Dv X509_V_ERR_CRL_NOT_YET_VALID : No CRL is not yet valid
The CRL is not yet valid.
.It Dv X509_V_ERR_CRL_HAS_EXPIRED : No CRL has expired
The CRL has expired.
.It Dv X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD : \
 No format error in certificate's notBefore field
The certificate notBefore field contains an invalid time.
.It Dv X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD : \
 No format error in certificate's notAfter field
The certificate notAfter field contains an invalid time.
.It Dv X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD : \
 No format error in CRL's lastUpdate field
The CRL lastUpdate field contains an invalid time.
.It Dv X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD : \
 No format error in CRL's nextUpdate field
The CRL nextUpdate field contains an invalid time.
.It Dv X509_V_ERR_OUT_OF_MEM : No out of memory
An error occurred trying to allocate memory.
This should never happen.
.It Dv X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT : No self signed certificate
The passed certificate is self signed and the same certificate cannot be
found in the list of trusted certificates.
.It Dv X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN : \
 No 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.
.It Dv X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY : \
 No 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.
.It Dv X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE : \
 No unable to verify the first certificate
No signatures could be verified because the chain contains only one
certificate and it is not self signed.
.It Dv X509_V_ERR_CERT_CHAIN_TOO_LONG : No certificate chain too long
The certificate chain length is greater than the supplied maximum depth.
Unused.
.It Dv X509_V_ERR_CERT_REVOKED : No certificate revoked
The certificate has been revoked.
.It Dv X509_V_ERR_INVALID_CA : No invalid CA certificate
A CA certificate is invalid.
Either it is not a CA or its extensions are not consistent with the
supplied purpose.
.It Dv X509_V_ERR_PATH_LENGTH_EXCEEDED : No path length constraint exceeded
The basicConstraints path-length parameter has been exceeded.
.It Dv X509_V_ERR_INVALID_PURPOSE : No unsupported certificate purpose
The supplied certificate cannot be used for the specified purpose.
.It Dv X509_V_ERR_CERT_UNTRUSTED : No certificate not trusted
The root CA is not marked as trusted for the specified purpose.
.It Dv X509_V_ERR_CERT_REJECTED : No certificate rejected
The root CA is marked to reject the specified purpose.
.It Dv X509_V_ERR_SUBJECT_ISSUER_MISMATCH : No 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
.Sy not
in itself an error.
.It Dv X509_V_ERR_AKID_SKID_MISMATCH : \
 No 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
.Sy not
in itself an error.
.It Dv X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH : \
 Noauthority 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
.Sy not
in itself an error.
.It Dv X509_V_ERR_KEYUSAGE_NO_CERTSIGN : \
 No 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
.Sy not
in itself an error.
.It Dv X509_V_ERR_INVALID_EXTENSION : \
 No invalid or inconsistent certificate extension
A certificate extension had an invalid value (for example an incorrect
encoding) or some value inconsistent with other extensions.
.It Dv X509_V_ERR_INVALID_POLICY_EXTENSION : \
 No 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.
.It Dv X509_V_ERR_NO_EXPLICIT_POLICY : No no explicit policy
The verification flags were set to require an explicit policy but none
was present.
.It Dv X509_V_ERR_DIFFERENT_CRL_SCOPE : No different CRL scope
The only CRLs that could be found did not match the scope of the
certificate.
.It Dv X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE : \
 No unsupported extension feature
Some feature of a certificate extension is not supported.
Unused.
.It Dv X509_V_ERR_PERMITTED_VIOLATION : No permitted subtree violation
A name constraint violation occurred in the permitted subtrees.
.It Dv X509_V_ERR_EXCLUDED_VIOLATION : No excluded subtree violation
A name constraint violation occurred in the excluded subtrees.
.It Dv X509_V_ERR_SUBTREE_MINMAX : \
 No name constraints minimum and maximum not supported
A certificate name constraints extension included a minimum or maximum
field: this is not supported.
.It Dv X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE : \
 No unsupported name constraint type
An unsupported name constraint type was encountered.
OpenSSL currently only supports directory name, DNS name, email and URI
types.
.It Dv X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX : \
 No 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.
.It Dv X509_V_ERR_CRL_PATH_VALIDATION_ERROR : No 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.
.It Dv X509_V_ERR_APPLICATION_VERIFICATION : \
 No application verification failure
An application specific error.
This will never be returned unless explicitly set by an application.
.El
.Sh SEE ALSO
.Xr X509_STORE_CTX_new 3 ,
.Xr X509_up_ref 3 ,
.Xr X509_verify_cert 3
.Sh HISTORY
.Fn X509_STORE_CTX_get_error ,
.Fn X509_STORE_CTX_set_error ,
.Fn X509_STORE_CTX_get_error_depth ,
.Fn X509_STORE_CTX_get_current_cert ,
and
.Fn X509_verify_cert_error_string
first appeared in SSLeay 0.8.0 and have been available since
.Ox 2.4 .
.Pp
.Fn X509_STORE_CTX_get1_chain
first appeared in OpenSSL 0.9.5 and has been available since
.Ox 2.7 .
.Pp
.Fn X509_STORE_CTX_get0_cert
and
.Fn X509_STORE_CTX_get0_chain
first appeared in OpenSSL 1.1.0 and have been available since
.Ox 6.3 .