1=pod 2 3=head1 NAME 4 5EVP_MAC-BLAKE2, EVP_MAC-BLAKE2BMAC, EVP_MAC-BLAKE2SMAC 6- The BLAKE2 EVP_MAC implementations 7 8=head1 DESCRIPTION 9 10Support for computing BLAKE2 MACs through the B<EVP_MAC> API. 11 12=head2 Identity 13 14These implementations are identified with one of these names and 15properties, to be used with EVP_MAC_fetch(): 16 17=over 4 18 19=item "BLAKE2BMAC", "provider=default" 20 21=item "BLAKE2SMAC", "provider=default" 22 23=back 24 25=head2 Supported parameters 26 27The general description of these parameters can be found in 28L<EVP_MAC(3)/PARAMETERS>. 29 30All these parameters can be set with EVP_MAC_CTX_set_params(). 31Furthermore, the "size" parameter can be retrieved with 32EVP_MAC_CTX_get_params(), or with EVP_MAC_CTX_get_mac_size(). 33The length of the "size" parameter should not exceed that of a B<size_t>. 34Likewise, the "block-size" parameter can be retrieved with 35EVP_MAC_CTX_get_params(), or with EVP_MAC_CTX_get_block_size(). 36 37=over 4 38 39=item "key" (B<OSSL_MAC_PARAM_KEY>) <octet string> 40 41Sets the MAC key. 42It may be at most 64 bytes for BLAKE2BMAC or 32 for BLAKE2SMAC and at 43least 1 byte in both cases. 44Setting this parameter is identical to passing a I<key> to L<EVP_MAC_init(3)>. 45 46=item "custom" (B<OSSL_MAC_PARAM_CUSTOM>) <octet string> 47 48Sets the custom value. 49It is an optional value of at most 16 bytes for BLAKE2BMAC or 8 for 50BLAKE2SMAC, and is empty by default. 51 52=item "salt" (B<OSSL_MAC_PARAM_SALT>) <octet string> 53 54Sets the salt. 55It is an optional value of at most 16 bytes for BLAKE2BMAC or 8 for 56BLAKE2SMAC, and is empty by default. 57 58=item "size" (B<OSSL_MAC_PARAM_SIZE>) <unsigned integer> 59 60Sets the MAC size. 61It can be any number between 1 and 32 for EVP_MAC_BLAKE2S or between 1 62and 64 for EVP_MAC_BLAKE2B. 63It is 32 and 64 respectively by default. 64 65=item "block-size" (B<OSSL_MAC_PARAM_SIZE>) <unsigned integer> 66 67Gets the MAC block size. 68By default, it is 64 for EVP_MAC_BLAKE2S and 128 for EVP_MAC_BLAKE2B. 69 70=back 71 72=head1 SEE ALSO 73 74L<EVP_MAC_CTX_get_params(3)>, L<EVP_MAC_CTX_set_params(3)>, 75L<EVP_MAC(3)/PARAMETERS>, L<OSSL_PARAM(3)> 76 77=head1 HISTORY 78 79The macros and functions described here were added to OpenSSL 3.0. 80 81=head1 COPYRIGHT 82 83Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved. 84 85Licensed under the Apache License 2.0 (the "License"). You may not use 86this file except in compliance with the License. You can obtain a copy 87in the file LICENSE in the source distribution or at 88L<https://www.openssl.org/source/license.html>. 89 90=cut 91