X509_STORE_CTX_GET_ERROR(3) | Library Functions Manual | X509_STORE_CTX_GET_ERROR(3)

# NAME

`X509_STORE_CTX_get_error`, `X509_STORE_CTX_set_error`, `X509_STORE_CTX_get_error_depth`, `X509_STORE_CTX_set_error_depth`, `X509_STORE_CTX_get_current_cert`, `X509_STORE_CTX_set_current_cert`, `X509_STORE_CTX_get0_current_issuer`, `X509_STORE_CTX_get0_current_crl`, `X509_STORE_CTX_get0_parent_ctx`, `X509_STORE_CTX_get_num_untrusted`, `X509_STORE_CTX_get0_chain`, `X509_STORE_CTX_get_chain`, `X509_STORE_CTX_get1_chain`, `X509_STORE_CTX_set0_verified_chain`, `X509_verify_cert_error_string` — get or set certificate verification status information

# SYNOPSIS

library “libcrypto”
`#include <openssl/x509_vfy.h>`

int
`X509_STORE_CTX_get_error`(X509_STORE_CTX *ctx);

void
`X509_STORE_CTX_set_error`(X509_STORE_CTX *ctx, int s);

int
`X509_STORE_CTX_get_error_depth`(X509_STORE_CTX *ctx);

void
`X509_STORE_CTX_set_error_depth`(X509_STORE_CTX *ctx, int depth);

X509 *
`X509_STORE_CTX_get_current_cert`(X509_STORE_CTX *ctx);

void
`X509_STORE_CTX_set_current_cert`(X509_STORE_CTX *ctx, X509 *cert);

X509 *
`X509_STORE_CTX_get0_current_issuer`(X509_STORE_CTX *ctx);

X509_CRL *
`X509_STORE_CTX_get0_current_crl`(X509_STORE_CTX *ctx);

X509_STORE_CTX *
`X509_STORE_CTX_get0_parent_ctx`(X509_STORE_CTX *ctx);

int
`X509_STORE_CTX_get_num_untrusted`(X509_STORE_CTX *ctx);

STACK_OF(X509) *
`X509_STORE_CTX_get0_chain`(X509_STORE_CTX *ctx);

STACK_OF(X509) *
`X509_STORE_CTX_get_chain`(X509_STORE_CTX *ctx);

STACK_OF(X509) *
`X509_STORE_CTX_get1_chain`(X509_STORE_CTX *ctx);

void
`X509_STORE_CTX_set0_verified_chain`(X509_STORE_CTX *ctx, STACK_OF(X509) *chain);

`#include <openssl/x509.h>`

const char *
`X509_verify_cert_error_string`(long n);

# DESCRIPTION

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.

`X509_STORE_CTX_get_error`() returns the error code of ctx. See the ERROR CODES section for a full description of all error codes.

`X509_STORE_CTX_set_error`() 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.

`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.

`X509_STORE_CTX_set_error_depth`() 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.

`X509_STORE_CTX_get_current_cert`() returns the certificate in ctx which caused the error or `NULL` if no certificate is relevant.

`X509_STORE_CTX_set_current_cert`() 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).

`X509_STORE_CTX_get0_current_issuer`() returns the certificate that caused issuer validation to fail or `NULL` if no CA certificate is relevant.

`X509_STORE_CTX_get0_current_crl`() 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 `X509_STORE_CTX_get0_parent_ctx`() 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.

`X509_STORE_CTX_get0_chain`() 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. `X509_STORE_CTX_get_chain`() is a deprecated alias of `X509_STORE_CTX_get0_chain`(). `X509_STORE_CTX_get1_chain`() 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 `sk_X509_pop_free`(chain, X509_free).

`X509_STORE_CTX_set0_verified_chain`() 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 the caller.

`X509_verify_cert_error_string`() returns a human readable error string for verification error n.

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 `X509_STORE_CTX_get_current_cert`() was never `NULL`. Applications should check the return value before printing out any debugging information relating to the current certificate.

If an unrecognised error code is passed to `X509_verify_cert_error_string`(), "Unknown certificate verification error" is returned. This should never happen unless an invalid code is passed.

# RETURN VALUES

`X509_STORE_CTX_get_error`() returns `X509_V_OK` or an error code.

`X509_STORE_CTX_get_error_depth`() returns a non-negative error depth.

`X509_STORE_CTX_get_current_cert`(), `X509_STORE_CTX_get0_current_issuer`(), and `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.

`X509_STORE_CTX_get0_parent_ctx`() returns the parent context or `NULL` if ctx is not a temporary child context used for path validation of a CRL issuer certificate.

`X509_STORE_CTX_get_num_untrusted`() returns the number of untrusted certificates that were used in building the chain during a call to X509_verify_cert(3).

`X509_STORE_CTX_get0_chain`(), `X509_STORE_CTX_get_chain`(), and `X509_STORE_CTX_get1_chain`() return a pointer to a stack of certificates or `NULL` if an error occurs.

`X509_verify_cert_error_string`() returns a human readable error string for verification error n.

# 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".

`X509_V_OK`: ok
  The operation was successful.
`X509_V_ERR_UNSPECIFIED`: Unspecified certificate verification error
  An error was encountered during certificate verification and the internal routines failed to set a more specific error.
`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 thisUpdate field (sic!) contains an invalid time. Both the name of the error constant and the text of the error message give a wrong name for the field that contains the problem.
`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.
`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_UNABLE_TO_GET_CRL_ISSUER`: unable to get CRL issuer certificate
  The CRL's issuer could not be found: there is no alternative CRL issuer set on ctx and the last certificate in the chain is not self signed.
`X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION`: unhandled critical extension
  The certificate contains a critical extension that is unsupported by the library.
`X509_V_ERR_KEYUSAGE_NO_CRL_SIGN`: key usage does not include CRL signing
  The CRL issuer has a key usage extension with unset cRLSign bit.
`X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION`: unhandled critical CRL extension
  The CRL contains a critical extension that is unsupported by the library.
`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_UNNESTED_RESOURCE`: 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_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.
`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.

# SEE ALSO

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)

# HISTORY

`X509_STORE_CTX_get_error`(), `X509_STORE_CTX_set_error`(), `X509_STORE_CTX_get_error_depth`(), `X509_STORE_CTX_get_current_cert`(), `X509_STORE_CTX_get_chain`(), and `X509_verify_cert_error_string`() first appeared in SSLeay 0.8.0 and have been available since OpenBSD 2.4.

`X509_STORE_CTX_get1_chain`() first appeared in OpenSSL 0.9.5 and has been available since OpenBSD 2.7.

`X509_STORE_CTX_get0_current_issuer`(), `X509_STORE_CTX_get0_current_crl`(), and `X509_STORE_CTX_get0_parent_ctx`() first appeared in OpenSSL 1.0.0 and have been available since OpenBSD 4.9.

`X509_STORE_CTX_get0_chain`() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 6.3.

`X509_STORE_CTX_set_error_depth`(), `X509_STORE_CTX_set_current_cert`(), `X509_STORE_CTX_get_num_untrusted`(), and `X509_STORE_CTX_set0_verified_chain`() first appeared in OpenSSL 1.1.0 and have been available since OpenBSD 7.1.

June 8, 2025 | Debian