X509_STORE_CTX_GET_ERROR(3ossl)

💖 X509_STORE_CTX_get_error ✨ OpenSSL 3ossl manual page, part 1 🎀

✨ NAME ✨

okay so this page is about 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_cert, X509_STORE_CTX_get1_chain, and X509_verify_cert_error_string — get or set certificate verification status information 💖

🌸 SYNOPSIS 🌸

bestie, include this header first:

#include <openssl/x509.h>

int   X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx);
void  X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int s);
int   X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx);
void  X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth);
X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx);
void  X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x);
X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx);

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

const char *X509_verify_cert_error_string(long n);

💅 DESCRIPTION 💅

okay so these functions are typically called after certificate or chain verification using X509_verify_cert(3) or X509_STORE_CTX_verify(3) has indicated an error, or in a verification callback to determine the nature of an error. iykyk ✨

• X509_STORE_CTX_get_error() — returns the error code of ctx. ctx MUST NOT be NULL. See the "ERROR CODES" section for a full description of all error codes. It may return a code != X509_V_OK even if X509_verify_cert() did not indicate an error, likely because a verification callback function has waived the error. no cap.
• 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. ctx MUST NOT be NULL.
• X509_STORE_CTX_get_error_depth() — returns the depth of the error. This is a nonnegative 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. ctx MUST NOT be NULL.
• 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 current certificate in ctx. If an error occurred, the current certificate will be the one that is most closely related to the error, or possibly NULL if no such certificate is relevant.
• X509_STORE_CTX_set_current_cert() — sets the certificate x in ctx which caused the error. 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 to 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). the way that ownership thing matters 💅
• X509_STORE_CTX_get0_cert() — retrieves an internal pointer to the certificate being verified by the ctx. It may be NULL if a raw public key is being verified.
• X509_STORE_CTX_get1_chain() — returns a complete validate chain if a previous verification is successful. Otherwise the returned chain may be incomplete or invalid. The returned chain persists after the ctx structure is freed. When it is no longer needed it should be freed using:

OSSL_STACK_OF_X509_free(chain);

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

🦋 RETURN VALUES 🦋

• X509_STORE_CTX_get_error() returns X509_V_OK or an error code.
• X509_STORE_CTX_get_error_depth() returns a nonnegative error depth.
• X509_STORE_CTX_get_current_cert() returns the certificate which caused the error or NULL if no certificate is relevant to the error.
• 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". periodt 💖

• X509_V_OK: ok — The operation was successful. slay ✨
• X509_V_ERR_UNSPECIFIED: unspecified certificate verification error — Unspecified error; should not happen.
• 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. To allow any certificate (not only a self-signed one) in the trust store to terminate the chain the X509_V_FLAG_PARTIAL_CHAIN flag may be set.
• 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" field 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.
• 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 no suitable trust anchor (which typically is a self-signed root certificate) could be found in the trust store.
• 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 and the X509_V_FLAG_PARTIAL_CHAIN flag is not set.
• 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_NO_ISSUER_PUBLIC_KEY: issuer certificate doesn't have a public key — The issuer certificate does not have a public key.
• X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded — The basicConstraints path-length parameter has been exceeded.
• X509_V_ERR_INVALID_PURPOSE: unsuitable certificate purpose — The target 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.
• 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 of the current certificate.
• 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.
• 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.
• X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER: unable to get CRL issuer certificate — Unable to get CRL issuer certificate.
• X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION: unhandled critical extension — Unhandled critical extension.
• X509_V_ERR_KEYUSAGE_NO_CRL_SIGN: key usage does not include CRL signing — Key usage does not include CRL signing.
• X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION: unhandled critical CRL extension — Unhandled critical CRL extension.
• X509_V_ERR_INVALID_NON_CA: invalid non-CA certificate (has CA markings) — Invalid non-CA certificate has CA markings.
• X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED: proxy path length constraint exceeded — Proxy path length constraint exceeded.
• X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE: key usage does not include digital signature — Key usage does not include digital signature, and therefore cannot sign certificates.
• X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED — proxy certs not allowed, bestie, go set the right flag 💅 Proxy certificates are a no unless the X509_V_FLAG_ALLOW_PROXY_CERTS flag is set. That's the whole vibe.
• X509_V_ERR_INVALID_EXTENSION — invalid or inconsistent certificate extension. A cert extension had a bad value (think: an incorrect encoding) or some value that just doesn't match up with the other extensions. It's giving messy. 🙈
• X509_V_ERR_INVALID_POLICY_EXTENSION — invalid or inconsistent certificate policy extension. A certificate policies extension had an invalid value (again, incorrect encoding is the classic) or a value inconsistent with other extensions. Heads up: this one only shows up if policy processing is enabled. ⭐
• X509_V_ERR_NO_EXPLICIT_POLICY — no explicit policy. The verification flags said "we require an explicit policy, periodt" and then... there wasn't one. Not a single one. 😭
• X509_V_ERR_DIFFERENT_CRL_SCOPE — different CRL scope. The only CRLs that could be found did not match the scope of the certificate. So close and yet so far.
• X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE — unsupported extension feature. Some feature of a certificate extension is not supported. Also, it's unused. Iconic of it to just chill there. 💀
• X509_V_ERR_UNNESTED_RESOURCE — RFC 3779 resource not subset of parent's resources. Check RFC 3779 for the deets, bestie.
• X509_V_ERR_PERMITTED_VIOLATION — permitted subtree violation. A name constraint violation happened in the permitted subtrees. 🚨
• X509_V_ERR_EXCLUDED_VIOLATION — excluded subtree violation. A name constraint violation happened 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, and nope, that's not supported. 🫶
• X509_V_ERR_APPLICATION_VERIFICATION — application verification failure. This is an application specific error, and it will never be returned unless an application callback explicitly sets it. Like, never ever.
• X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE — unsupported name constraint type. An unsupported name constraint type got encountered. OpenSSL currently only supports directory name, DNS name, email and URI types. Those four, that's the roster. ✨
• X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX — unsupported or invalid name constraint syntax. The format of the name constraint isn't recognised — for example an email address format of a form not mentioned in RFC3280. Could be caused by a garbage extension, or some new feature that isn't currently supported. Rude either way. 🙈
• X509_V_ERR_UNSUPPORTED_NAME_SYNTAX — unsupported or invalid name syntax. Yeah. Unsupported or invalid name syntax. Short, sweet, devastating.
• X509_V_ERR_CRL_PATH_VALIDATION_ERROR — CRL path validation error. An error occurred when attempting to verify the CRL path. This one can only happen if extended CRL checking is enabled, iykyk.
• X509_V_ERR_PATH_LOOP — path loop. It's a path loop. 🔁
• X509_V_ERR_HOSTNAME_MISMATCH — hostname mismatch. Hostname mismatch. 💀
• X509_V_ERR_EMAIL_MISMATCH — email address mismatch. Email address mismatch.
• X509_V_ERR_IP_ADDRESS_MISMATCH — IP address mismatch. IP address mismatch. (The trio really said "no notes, just facts.")
• X509_V_ERR_DANE_NO_MATCH — no matching DANE TLSA records. DANE TLSA authentication is enabled, but no TLSA records matched the certificate chain. Fun fact: this error is only possible in openssl-s_client(1).
• X509_V_ERR_EE_KEY_TOO_SMALL — EE certificate key too weak. EE certificate key too weak, fr fr.
• X509_V_ERR_CA_KEY_TOO_SMALL — CA certificate key too weak. CA certificate key too weak.
• X509_V_ERR_CA_MD_TOO_WEAK — CA signature digest algorithm too weak. CA signature digest algorithm too weak.
• X509_V_ERR_INVALID_CALL — invalid certificate verification context. Invalid certificate verification context. 🫠
• X509_V_ERR_STORE_LOOKUP — issuer certificate lookup error. Issuer certificate lookup error.
• X509_V_ERR_NO_VALID_SCTS — certificate transparency required, but no valid SCTs found. Certificate Transparency required, but no valid SCTs found. The CT vibes were not immaculate. 💅
• X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION — proxy subject name violation. Proxy subject name violation.
• X509_V_ERR_OCSP_VERIFY_NEEDED — OCSP verification needed. Returned by the verify callback to indicate an OCSP verification is needed. 📣
• X509_V_ERR_OCSP_VERIFY_FAILED — OCSP verification failed. Returned by the verify callback to indicate OCSP verification failed. 😭
• X509_V_ERR_OCSP_CERT_UNKNOWN — OCSP unknown cert. Returned by the verify callback to indicate that the certificate is not recognized by the OCSP responder. Stranger danger.
• X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM — unsupported signature algorithm. Cannot find certificate signature algorithm. Nowhere. Gone. 👻
• X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH — subject signature algorithm and issuer public key algorithm mismatch. The issuer's public key is not of the type required by the signature in the subject's certificate. They're simply not compatible bestie, it's not gonna work.
• X509_V_ERR_SIGNATURE_ALGORITHM_INCONSISTENCY — cert info signature and signature algorithm mismatch. The algorithm given in the certificate info is inconsistent with the one used for the certificate signature. Pick a lane. 🚩
• 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. Both options are a flop.
• X509_V_ERR_RPK_UNTRUSTED — raw public key untrusted, no trusted keys configured. No TLS records were configured to validate the raw public key, or DANE was not enabled on the connection. 💀

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📝 NOTES

These functions here? Use them. Like, use the above functions instead of directly referencing the fields in the X509_VERIFY_CTX structure. Do not go poking at the internals, that's not the move. 🫶

In versions of OpenSSL before 1.0, the current certificate returned by X509_STORE_CTX_get_current_cert() was never NULL. So applications should check the return value before printing out any debugging information relating to the current certificate. Always check, bestie, it costs nothing. ⭐

If an unrecognised error code is passed to X509_verify_cert_error_string(), the numerical value of the unknown code is returned in a static buffer. This is not thread safe — but it will never happen unless an invalid code is passed, so it's lowkey fine as long as you're not out here passing nonsense. 😌

🐛 BUGS

Previous versions of this documentation swapped the meaning of the X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT and X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY error codes. Not me exposing the old docs like this. 💀 Anyway, now you know.

👀 SEE ALSO

X509_verify_cert(3), X509_STORE_CTX_verify(3), X509_up_ref(3), X509_free(3). Go read those next, bestie, they're the supporting cast. 🌈

©️ COPYRIGHT

Copyright 2009-2023 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

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And that's a wrap on part 2, babes 🎀 This whole thing lives in OpenSSL 3.5.9, dated 2026-09-29, filed under X509_STORE_CTX_GET_ERROR(3ossl). Go forth and verify those certs, you've got this. 👑💖