1=pod 2 3=head1 NAME 4 5X509_verify, X509_self_signed, 6X509_REQ_verify_ex, X509_REQ_verify, 7X509_CRL_verify, X509_ACERT_verify - 8verify certificate, certificate request, or CRL signature 9 10=head1 SYNOPSIS 11 12 #include <openssl/x509.h> 13 14 int X509_verify(X509 *x, EVP_PKEY *pkey); 15 int X509_self_signed(X509 *cert, int verify_signature); 16 17 int X509_REQ_verify_ex(X509_REQ *a, EVP_PKEY *pkey, OSSL_LIB_CTX *libctx, 18 const char *propq); 19 int X509_REQ_verify(X509_REQ *a, EVP_PKEY *r); 20 int X509_CRL_verify(X509_CRL *a, EVP_PKEY *r); 21 22 #include <openssl/x509_acert.h> 23 int X509_ACERT_verify(X509_CRL *a, EVP_PKEY *r); 24 25=head1 DESCRIPTION 26 27X509_verify() verifies the signature of certificate I<x> using public key 28I<pkey>. Only the signature is checked: no other checks (such as certificate 29chain validity) are performed. 30 31X509_self_signed() checks whether certificate I<cert> is self-signed. 32For success the issuer and subject names must match, the components of the 33authority key identifier (if present) must match the subject key identifier etc. 34The signature itself is actually verified only if B<verify_signature> is 1, as 35for explicitly trusted certificates this verification is not worth the effort. 36 37X509_REQ_verify_ex(), X509_REQ_verify(), X509_CRL_verify() and X509_ACERT_verify() 38verify the signatures of certificate requests, CRLs and attribute certificates 39respectively. 40 41=head1 RETURN VALUES 42 43X509_verify(), 44X509_REQ_verify_ex(), X509_REQ_verify() and X509_CRL_verify() 45return 1 if the signature is valid and 0 if the signature check fails. 46If the signature could not be checked at all because it was ill-formed, 47the certificate or the request was not complete or some other error occurred 48then -1 is returned. 49 50X509_self_signed() returns the same values but also returns 1 51if all respective fields match and B<verify_signature> is 0. 52 53=head1 SEE ALSO 54 55L<d2i_X509(3)>, 56L<ERR_get_error(3)>, 57L<X509_CRL_get0_by_serial(3)>, 58L<X509_get0_signature(3)>, 59L<X509_get_ext_d2i(3)>, 60L<X509_get_extension_flags(3)>, 61L<X509_get_pubkey(3)>, 62L<X509_get_subject_name(3)>, 63L<X509_get_version(3)>, 64L<X509_NAME_ENTRY_get_object(3)>, 65L<X509_NAME_get_index_by_NID(3)>, 66L<X509_NAME_print_ex(3)>, 67L<X509V3_get_d2i(3)>, 68L<X509_verify_cert(3)>, 69L<OSSL_LIB_CTX(3)> 70 71=head1 HISTORY 72 73The X509_verify(), X509_REQ_verify(), and X509_CRL_verify() 74functions are available in all versions of OpenSSL. 75 76X509_REQ_verify_ex(), and X509_self_signed() were added in OpenSSL 3.0. 77 78X509_ACERT_verify() was added in OpenSSL 3.4. 79 80=head1 COPYRIGHT 81 82Copyright 2015-2024 The OpenSSL Project Authors. All Rights Reserved. 83 84Licensed under the Apache License 2.0 (the "License"). You may not use 85this file except in compliance with the License. You can obtain a copy 86in the file LICENSE in the source distribution or at 87L<https://www.openssl.org/source/license.html>. 88 89=cut 90
