1.\" $OpenBSD: EVP_PKEY_get_default_digest_nid.3,v 1.10 2024/12/06 12:51:13 schwarze Exp $ 2.\" full merge up to: OpenSSL df75c2bf Dec 9 01:02:36 2018 +0100 3.\" 4.\" This file is a derived work. 5.\" The changes are covered by the following Copyright and license: 6.\" 7.\" Copyright (c) 2023 Ingo Schwarze <schwarze@openbsd.org> 8.\" 9.\" Permission to use, copy, modify, and distribute this software for any 10.\" purpose with or without fee is hereby granted, provided that the above 11.\" copyright notice and this permission notice appear in all copies. 12.\" 13.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20.\" 21.\" The original file was written by Dr. Stephen Henson <steve@openssl.org>. 22.\" Copyright (c) 2006, 2009, 2013, 2018 The OpenSSL Project. 23.\" All rights reserved. 24.\" 25.\" Redistribution and use in source and binary forms, with or without 26.\" modification, are permitted provided that the following conditions 27.\" are met: 28.\" 29.\" 1. Redistributions of source code must retain the above copyright 30.\" notice, this list of conditions and the following disclaimer. 31.\" 32.\" 2. 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Redistributions of any form whatsoever must retain the following 52.\" acknowledgment: 53.\" "This product includes software developed by the OpenSSL Project 54.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 55.\" 56.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 57.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 58.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 60.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 61.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 62.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 63.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 64.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 65.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 66.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 67.\" OF THE POSSIBILITY OF SUCH DAMAGE. 68.\" 69.Dd $Mdocdate: December 6 2024 $ 70.Dt EVP_PKEY_GET_DEFAULT_DIGEST_NID 3 71.Os 72.Sh NAME 73.Nm EVP_PKEY_get_default_digest_nid 74.Nd get default signature digest 75.Sh SYNOPSIS 76.In openssl/evp.h 77.Ft int 78.Fo EVP_PKEY_get_default_digest_nid 79.Fa "EVP_PKEY *pkey" 80.Fa "int *pnid" 81.Fc 82.Sh DESCRIPTION 83The 84.Fn EVP_PKEY_get_default_digest_nid 85function sets 86.Pf * Fa pnid 87to the default message digest NID for the public key signature 88operations associated with 89.Fa pkey . 90.Pp 91Some signature algorithms, for example 92.Dv EVP_PKEY_ED25519 , 93do not use a digest during signing. 94In this case, 95.Pf * Fa pnid 96is set to 97.Dv NID_undef . 98.Pp 99Support for the following public key algorithms is built into the library: 100.Pp 101.Bl -column -compact EVP_PKEY_base_id(3) NID_sha256 mandatory 102.It Xr EVP_PKEY_base_id 3 Ta Pf * Fa pnid Ta return value 103.It Dv EVP_PKEY_DSA Ta Dv NID_sha1 Ta mandatory 104.It Dv EVP_PKEY_EC Ta Dv NID_sha1 Ta mandatory 105.It Dv EVP_PKEY_ED25519 Ta Dv NID_undef Ta mandatory 106.It Dv EVP_PKEY_HMAC Ta Dv NID_sha1 Ta advisory 107.It Dv EVP_PKEY_RSA Ta Dv NID_sha256 Ta advisory 108.El 109.Sh RETURN VALUES 110The 111.Fn EVP_PKEY_get_default_digest_nid 112function returns 1 if the message digest is advisory (that is other 113digests can be used) and 2 if it is mandatory (other digests cannot be 114used). 115It returns 0 or a negative value for failure. 116In particular, a return value of -2 indicates the operation is not 117supported by the public key algorithm. 118.Sh SEE ALSO 119.Xr EVP_PKEY_CTX_ctrl 3 , 120.Xr EVP_PKEY_CTX_new 3 , 121.Xr EVP_PKEY_new 3 , 122.Xr EVP_PKEY_sign 3 , 123.Xr EVP_PKEY_verify 3 , 124.Xr EVP_PKEY_verify_recover 3 125.Sh HISTORY 126.Fn EVP_PKEY_get_default_digest_nid 127first appeared in OpenSSL 1.0.0 and has been available since 128.Ox 4.9 . 129