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X509_CMP(3ossl) OpenSSL X509_CMP(3ossl)
NAME
X509_cmp, X509_NAME_cmp, X509_issuer_and_serial_cmp,
X509_issuer_name_cmp, X509_subject_name_cmp, X509_CRL_cmp,
X509_CRL_match - compare X509 certificates and related values
SYNOPSIS
#include <openssl/x509.h>
int X509_cmp(const X509 *a, const X509 *b);
int X509_NAME_cmp(const X509_NAME *a, const X509_NAME *b);
int X509_issuer_and_serial_cmp(const X509 *a, const X509 *b);
int X509_issuer_name_cmp(const X509 *a, const X509 *b);
int X509_subject_name_cmp(const X509 *a, const X509 *b);
int X509_CRL_cmp(const X509_CRL *a, const X509_CRL *b);
int X509_CRL_match(const X509_CRL *a, const X509_CRL *b);
DESCRIPTION
This set of functions are used to compare X509 objects, including X509
certificates, X509 CRL objects and various values in an X509
certificate.
The X509_cmp() function compares two X509 objects indicated by
parameters a and b. The comparison is based on the memcmp result of the
hash values of two X509 objects and the canonical (DER) encoding
values.
The X509_NAME_cmp() function compares two X509_NAME objects indicated
by parameters a and b. The comparison is based on the memcmp result of
the canonical (DER) encoding values of the two objects using
i2d_X509_NAME(3). This procedure adheres to the matching rules for
Distinguished Names (DN) given in RFC 4517 section 4.2.15 and RFC 5280
section 7.1. In particular, the order of Relative Distinguished Names
(RDNs) is relevant. On the other hand, if an RDN is multi-valued,
i.e., it contains a set of AttributeValueAssertions (AVAs), its members
are effectively not ordered.
The X509_issuer_and_serial_cmp() function compares the serial number
and issuer values in the given X509 objects a and b.
The X509_issuer_name_cmp(), X509_subject_name_cmp() and X509_CRL_cmp()
functions are effectively wrappers of the X509_NAME_cmp() function.
These functions compare issuer names and subject names of the objects,
or issuers of X509_CRL objects, respectively.
The X509_CRL_match() function compares two X509_CRL objects. Unlike the
X509_CRL_cmp() function, this function compares the whole CRL content
instead of just the issuer name.
RETURN VALUES
The X509 comparison functions return -1, 0, or 1 if object a is found
to be less than, to match, or be greater than object b, respectively.
X509_NAME_cmp(), X509_issuer_and_serial_cmp(), X509_issuer_name_cmp(),
X509_subject_name_cmp(), X509_CRL_cmp(), and X509_CRL_match() may
return -2 to indicate an error.
X509_NAME_cmp() and wrappers utilize the value -2 to indicate errors in
some circumstances, which could cause confusion for the applications.
SEE ALSO
i2d_X509_NAME(3), i2d_X509(3)
COPYRIGHT
Copyright 2019-2021 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>.
3.0.11 2023-09-19 X509_CMP(3ossl)