1.\" $OpenBSD: EVP_PKEY_cmp.3,v 1.10 2019/06/06 01:06:58 schwarze Exp $ 2.\" OpenSSL 05ea606a May 20 20:52:46 2016 -0400 3.\" 4.\" This file was written by Dr. Stephen Henson <steve@openssl.org>. 5.\" Copyright (c) 2006, 2013, 2014, 2016 The OpenSSL Project. 6.\" All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in 17.\" the documentation and/or other materials provided with the 18.\" distribution. 19.\" 20.\" 3. All advertising materials mentioning features or use of this 21.\" software must display the following acknowledgment: 22.\" "This product includes software developed by the OpenSSL Project 23.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 24.\" 25.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26.\" endorse or promote products derived from this software without 27.\" prior written permission. For written permission, please contact 28.\" openssl-core@openssl.org. 29.\" 30.\" 5. Products derived from this software may not be called "OpenSSL" 31.\" nor may "OpenSSL" appear in their names without prior written 32.\" permission of the OpenSSL Project. 33.\" 34.\" 6. Redistributions of any form whatsoever must retain the following 35.\" acknowledgment: 36.\" "This product includes software developed by the OpenSSL Project 37.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 38.\" 39.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50.\" OF THE POSSIBILITY OF SUCH DAMAGE. 51.\" 52.Dd $Mdocdate: June 6 2019 $ 53.Dt EVP_PKEY_CMP 3 54.Os 55.Sh NAME 56.Nm EVP_PKEY_missing_parameters , 57.Nm EVP_PKEY_copy_parameters , 58.Nm EVP_PKEY_cmp_parameters , 59.Nm EVP_PKEY_cmp 60.Nd public key parameter and comparison functions 61.Sh SYNOPSIS 62.In openssl/evp.h 63.Ft int 64.Fo EVP_PKEY_missing_parameters 65.Fa "const EVP_PKEY *pkey" 66.Fc 67.Ft int 68.Fo EVP_PKEY_copy_parameters 69.Fa "EVP_PKEY *to" 70.Fa "const EVP_PKEY *from" 71.Fc 72.Ft int 73.Fo EVP_PKEY_cmp_parameters 74.Fa "const EVP_PKEY *a" 75.Fa "const EVP_PKEY *b" 76.Fc 77.Ft int 78.Fo EVP_PKEY_cmp 79.Fa "const EVP_PKEY *a" 80.Fa "const EVP_PKEY *b" 81.Fc 82.Sh DESCRIPTION 83The function 84.Fn EVP_PKEY_missing_parameters 85returns 1 if the public key parameters of 86.Fa pkey 87are missing and 0 if they are present or the algorithm doesn't use 88parameters. 89.Pp 90The function 91.Fn EVP_PKEY_copy_parameters 92copies the parameters from key 93.Fa from 94to key 95.Fa to . 96An error is returned if the parameters are missing in 97.Fa from . 98.Pp 99The function 100.Fn EVP_PKEY_cmp_parameters 101compares the parameters of keys 102.Fa a 103and 104.Fa b . 105.Pp 106The function 107.Fn EVP_PKEY_cmp 108compares the public key components and parameters (if present) of keys 109.Fa a 110and 111.Fa b . 112.Pp 113The main purpose of the functions 114.Fn EVP_PKEY_missing_parameters 115and 116.Fn EVP_PKEY_copy_parameters 117is to handle public keys in certificates where the parameters are 118sometimes omitted from a public key if they are inherited from the CA 119that signed it. 120.Pp 121Since OpenSSL private keys contain public key components too, the 122function 123.Fn EVP_PKEY_cmp 124can also be used to determine if a private key matches a public key. 125.Sh RETURN VALUES 126The function 127.Fn EVP_PKEY_missing_parameters 128returns 1 if the public key parameters of 129.Fa pkey 130are missing and 0 if they are present or the algorithm doesn't use 131parameters. 132.Pp 133The function 134.Fn EVP_PKEY_copy_parameters 135returns 1 for success and 0 for failure. 136.Pp 137The functions 138.Fn EVP_PKEY_cmp_parameters 139and 140.Fn EVP_PKEY_cmp 141return 1 if the keys match, 0 if they don't match, -1 if the key types 142are different and -2 if the operation is not supported. 143.Sh SEE ALSO 144.Xr EVP_PKEY_asn1_set_public 3 , 145.Xr EVP_PKEY_CTX_new 3 , 146.Xr EVP_PKEY_keygen 3 , 147.Xr EVP_PKEY_new 3 148.Sh HISTORY 149.Fn EVP_PKEY_missing_parameters 150and 151.Fn EVP_PKEY_copy_parameters 152first appeared in SSLeay 0.8.0. 153.Fn EVP_PKEY_cmp_parameters 154first appeared in SSLeay 0.9.0. 155These functions have been available since 156.Ox 2.4 . 157.Pp 158.Fn EVP_PKEY_cmp 159first appeared in OpenSSL 0.9.8 and has been available since 160.Ox 4.5 . 161