1=pod 2 3=head1 NAME 4 5EVP_PKEY_missing_parameters, EVP_PKEY_copy_parameters, EVP_PKEY_parameters_eq, 6EVP_PKEY_cmp_parameters, EVP_PKEY_eq, 7EVP_PKEY_cmp - public key parameter and comparison functions 8 9=head1 SYNOPSIS 10 11 #include <openssl/evp.h> 12 13 int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey); 14 int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from); 15 16 int EVP_PKEY_parameters_eq(const EVP_PKEY *a, const EVP_PKEY *b); 17 int EVP_PKEY_eq(const EVP_PKEY *a, const EVP_PKEY *b); 18 19The following functions have been deprecated since OpenSSL 3.0, and can be 20hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 21see L<openssl_user_macros(7)>: 22 23 int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b); 24 int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b); 25 26=head1 DESCRIPTION 27 28The function EVP_PKEY_missing_parameters() returns 1 if the public key 29parameters of B<pkey> are missing and 0 if they are present or the algorithm 30doesn't use parameters. 31 32The function EVP_PKEY_copy_parameters() copies the parameters from key 33B<from> to key B<to>. An error is returned if the parameters are missing in 34B<from> or present in both B<from> and B<to> and mismatch. If the parameters 35in B<from> and B<to> are both present and match this function has no effect. 36 37The function EVP_PKEY_parameters_eq() checks the parameters of keys 38B<a> and B<b> for equality. 39 40The function EVP_PKEY_eq() checks the keys B<a> and B<b> for equality, 41including their parameters if they are available. 42 43=head1 NOTES 44 45The main purpose of the functions EVP_PKEY_missing_parameters() and 46EVP_PKEY_copy_parameters() is to handle public keys in certificates where the 47parameters are sometimes omitted from a public key if they are inherited from 48the CA that signed it. 49 50The deprecated functions EVP_PKEY_cmp() and EVP_PKEY_cmp_parameters() differ in 51their return values compared to other _cmp() functions. They are aliases for 52EVP_PKEY_eq() and EVP_PKEY_parameters_eq(). 53 54The function EVP_PKEY_cmp() previously only checked the key parameters 55(if there are any) and the public key, assuming that there always was 56a public key and that private key equality could be derived from that. 57Because it's no longer assumed that the private key in an L<EVP_PKEY(3)> is 58always accompanied by a public key, the comparison can not rely on public 59key comparison alone. 60 61Instead, EVP_PKEY_eq() (and therefore also EVP_PKEY_cmp()) now compares: 62 63=over 4 64 65=item 1. 66 67the key parameters (if there are any) 68 69=item 2. 70 71the public keys or the private keys of the two B<EVP_PKEY>s, depending on 72what they both contain. 73 74=back 75 76=begin comment 77 78Exactly what is compared is ultimately at the discretion of the provider 79that holds the key, as they will compare what makes sense to them that fits 80the selector bits they are passed. 81 82=end comment 83 84=head1 RETURN VALUES 85 86The function EVP_PKEY_missing_parameters() returns 1 if the public key 87parameters of B<pkey> are missing and 0 if they are present or the algorithm 88doesn't use parameters. 89 90These functions EVP_PKEY_copy_parameters() returns 1 for success and 0 for 91failure. 92 93The functions EVP_PKEY_cmp_parameters(), EVP_PKEY_parameters_eq(), 94EVP_PKEY_cmp() and EVP_PKEY_eq() return 1 if their 95inputs match, 0 if they don't match, -1 if the key types are different and 96-2 if the operation is not supported. 97 98=head1 SEE ALSO 99 100L<EVP_PKEY_CTX_new(3)>, 101L<EVP_PKEY_keygen(3)> 102 103=head1 HISTORY 104 105The EVP_PKEY_cmp() and EVP_PKEY_cmp_parameters() functions were deprecated in 106OpenSSL 3.0. 107 108The EVP_PKEY_eq() and EVP_PKEY_parameters_eq() were added in OpenSSL 3.0 to 109replace EVP_PKEY_cmp() and EVP_PKEY_cmp_parameters(). 110 111=head1 COPYRIGHT 112 113Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved. 114 115Licensed under the Apache License 2.0 (the "License"). You may not use 116this file except in compliance with the License. You can obtain a copy 117in the file LICENSE in the source distribution or at 118L<https://www.openssl.org/source/license.html>. 119 120=cut 121