.\" $OpenBSD: X509_cmp.3,v 1.4 2024/06/07 14:00:09 job Exp $ .\" full merge up to: OpenSSL ea5d4b89 Jun 6 11:42:02 2019 +0800 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2019 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .\" The original file was written by Paul Yang . .\" Copyright (c) 2019 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. All advertising materials mentioning features or use of this .\" software must display the following acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" .\" .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For written permission, please contact .\" openssl-core@openssl.org. .\" .\" 5. Products derived from this software may not be called "OpenSSL" .\" nor may "OpenSSL" appear in their names without prior written .\" permission of the OpenSSL Project. .\" .\" 6. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by the OpenSSL Project .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" .\" .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: June 7 2024 $ .Dt X509_CMP 3 .Os .Sh NAME .Nm X509_cmp , .Nm X509_NAME_cmp , .\" The alias X509_name_cmp(3) is intentionally undocumented .\" because it is almost unused in real-world code. .Nm X509_issuer_and_serial_cmp , .Nm X509_issuer_name_cmp , .Nm X509_subject_name_cmp , .Nm X509_CRL_cmp , .Nm X509_CRL_match .Nd compare X.509 certificates and related values .\" The function name_cmp() is intentionally undocumented. .\" It was a mistake to make it public in the first place, .\" and it is no longer part of the public API in OpenSSL 1.1. .Sh SYNOPSIS .In openssl/x509.h .Ft int .Fo X509_cmp .Fa "const X509 *a" .Fa "const X509 *b" .Fc .Ft int .Fo X509_NAME_cmp .Fa "const X509_NAME *a" .Fa "const X509_NAME *b" .Fc .Ft int .Fo X509_issuer_and_serial_cmp .Fa "const X509 *a" .Fa "const X509 *b" .Fc .Ft int .Fo X509_issuer_name_cmp .Fa "const X509 *a" .Fa "const X509 *b" .Fc .Ft int .Fo X509_subject_name_cmp .Fa "const X509 *a" .Fa "const X509 *b" .Fc .Ft int .Fo X509_CRL_cmp .Fa "const X509_CRL *a" .Fa "const X509_CRL *b" .Fc .Ft int .Fo X509_CRL_match .Fa "const X509_CRL *a" .Fa "const X509_CRL *b" .Fc .Sh DESCRIPTION .Fn X509_cmp compares two X.509 certificates using .Xr memcmp 3 on the hashes of their canonical (DER) representations as generated with .Xr X509_digest 3 . The digest function is implementation-specific: LibreSSL uses SHA-512, other implementations use SHA-1. .Pp .Fn X509_NAME_cmp compares two X.501 .Vt Name objects using their canonical (DER) representations generated with .Xr i2d_X509_NAME 3 . .Pp .Fn X509_issuer_and_serial_cmp compares the .Fa issuer and .Fa serialNumber fields of two .Vt TBSCertificate structures, using .Fn X509_NAME_cmp for the .Fa issuer fields. .Pp .Fn X509_issuer_name_cmp compares the .Fa issuer fields of two .Vt TBSCertificate structures using .Fn X509_NAME_cmp . .Pp .Fn X509_subject_name_cmp compares the .Fa subject fields of two .Vt TBSCertificate structures using .Fn X509_NAME_cmp . .Pp .Fn X509_CRL_cmp is misnamed; it only compares the .Fa issuer fields of two .Vt TBSCertList structures using .Fn X509_NAME_cmp . .Pp .Fn X509_CRL_match compares two certificate revocation lists using .Xr memcmp 3 on the hashes of their canonical (DER) representations as generated with .Xr X509_CRL_digest 3 . The digest function is implementation-specific: LibreSSL uses SHA-512, other implementations use SHA-1. .Sh RETURN VALUES All these functions return 0 to indicate a match or a non-zero value to indicate a mismatch. .Pp .Fn X509_NAME_cmp , .Fn X509_issuer_and_serial_cmp , .Fn X509_issuer_name_cmp , .Fn X509_subject_name_cmp and .Fn X509_CRL_cmp may return -2 to indicate an error. .Sh SEE ALSO .Xr i2d_X509_NAME 3 , .Xr X509_CRL_new 3 , .Xr X509_digest 3 , .Xr X509_NAME_new 3 , .Xr X509_new 3 .Sh STANDARDS RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile .Bl -dash -compact -offset indent .It section 4.1: Basic Certificate Fields .It section 5.1: CRL Fields .El .Sh HISTORY .Fn X509_issuer_and_serial_cmp , .Fn X509_issuer_name_cmp , and .Fn X509_subject_name_cmp first appeared in SSLeay 0.5.1 and .Fn X509_NAME_cmp and .Fn X509_CRL_cmp in SSLeay 0.8.0. These functions have been available since .Ox 2.4 . .Pp .Fn X509_cmp first appeared in OpenSSL 0.9.5 and has been available since .Ox 2.7 . .Pp .Fn X509_CRL_match first appeared in OpenSSL 1.0.0 and has been available since .Ox 4.9 . .Sh BUGS For .Fn X509_NAME_cmp , .Fn X509_issuer_and_serial_cmp , .Fn X509_issuer_name_cmp , .Fn X509_subject_name_cmp and .Fn X509_CRL_cmp , the return value -2 sometimes indicates a mismatch and sometimes an error.