1=pod 2 3=head1 NAME 4 5EVP_MAC-GMAC - The GMAC EVP_MAC implementation 6 7=head1 DESCRIPTION 8 9Support for computing GMAC MACs through the B<EVP_MAC> API. 10 11This implementation uses EVP_CIPHER functions to get access to the underlying 12cipher. 13 14=head2 Identity 15 16This implementation is identified with this name and properties, to be 17used with EVP_MAC_fetch(): 18 19=over 4 20 21=item "GMAC", "provider=default" or "provider=fips" 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 30The following parameter can be set with EVP_MAC_CTX_set_params(): 31 32=over 4 33 34=item "key" (B<OSSL_MAC_PARAM_KEY>) <octet string> 35 36Sets the MAC key. 37Setting this parameter is identical to passing a I<key> to L<EVP_MAC_init(3)>. 38 39=item "iv" (B<OSSL_MAC_PARAM_IV>) <octet string> 40 41Sets the IV of the underlying cipher, when applicable. 42 43=item "cipher" (B<OSSL_MAC_PARAM_CIPHER>) <UTF8 string> 44 45Sets the name of the underlying cipher to be used. 46 47=item "properties" (B<OSSL_MAC_PARAM_PROPERTIES>) <UTF8 string> 48 49Sets the properties to be queried when trying to fetch the underlying cipher. 50This must be given together with the cipher naming parameter to be considered 51valid. 52 53=back 54 55The following parameters can be retrieved with 56EVP_MAC_CTX_get_params(): 57 58=over 4 59 60=item "size" (B<OSSL_MAC_PARAM_SIZE>) <unsigned integer> 61 62Gets the MAC size. 63 64=back 65 66The "size" parameter can also be retrieved with EVP_MAC_CTX_get_mac_size(). 67The length of the "size" parameter is equal to that of an B<unsigned int>. 68 69=head1 SEE ALSO 70 71L<EVP_MAC_CTX_get_params(3)>, L<EVP_MAC_CTX_set_params(3)>, 72L<EVP_MAC(3)/PARAMETERS>, L<OSSL_PARAM(3)> 73 74=head1 COPYRIGHT 75 76Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved. 77 78Licensed under the Apache License 2.0 (the "License"). You may not use 79this file except in compliance with the License. You can obtain a copy 80in the file LICENSE in the source distribution or at 81L<https://www.openssl.org/source/license.html>. 82 83=cut 84
