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X509_VERIFY(3ossl) OpenSSL X509_VERIFY(3ossl)
NAME
X509_verify, X509_self_signed, X509_REQ_verify_ex, X509_REQ_verify,
X509_CRL_verify - verify certificate, certificate request, or CRL
signature
SYNOPSIS
#include <openssl/x509.h>
int X509_verify(X509 *x, EVP_PKEY *pkey);
int X509_self_signed(X509 *cert, int verify_signature);
int X509_REQ_verify_ex(X509_REQ *a, EVP_PKEY *pkey, OSSL_LIB_CTX *libctx,
const char *propq);
int X509_REQ_verify(X509_REQ *a, EVP_PKEY *r);
int X509_CRL_verify(X509_CRL *a, EVP_PKEY *r);
DESCRIPTION
X509_verify() verifies the signature of certificate x using public key
pkey. Only the signature is checked: no other checks (such as
certificate chain validity) are performed.
X509_self_signed() checks whether certificate cert is self-signed. For
success the issuer and subject names must match, the components of the
authority key identifier (if present) must match the subject key
identifier etc. The signature itself is actually verified only if
verify_signature is 1, as for explicitly trusted certificates this
verification is not worth the effort.
X509_REQ_verify_ex(), X509_REQ_verify() and X509_CRL_verify() verify
the signatures of certificate requests and CRLs, respectively.
RETURN VALUES
X509_verify(), X509_REQ_verify_ex(), X509_REQ_verify() and
X509_CRL_verify() return 1 if the signature is valid and 0 if the
signature check fails. If the signature could not be checked at all
because it was ill-formed, the certificate or the request was not
complete or some other error occurred then -1 is returned.
X509_self_signed() returns the same values but also returns 1 if all
respective fields match and verify_signature is 0.
SEE ALSO
d2i_X509(3), ERR_get_error(3), X509_CRL_get0_by_serial(3),
X509_get0_signature(3), X509_get_ext_d2i(3),
X509_get_extension_flags(3), X509_get_pubkey(3),
X509_get_subject_name(3), X509_get_version(3),
X509_NAME_ENTRY_get_object(3), X509_NAME_get_index_by_NID(3),
X509_NAME_print_ex(3), X509V3_get_d2i(3), X509_verify_cert(3),
OSSL_LIB_CTX(3)
HISTORY
The X509_verify(), X509_REQ_verify(), and X509_CRL_verify() functions
are available in all versions of OpenSSL.
X509_REQ_verify_ex(), and X509_self_signed() were added in OpenSSL 3.0.
3.0.11 2023-09-19 X509_VERIFY(3ossl)