=pod

=head1 NAME

EVP_MAC_KMAC - The KMAC EVP_MAC implementation

=head1 DESCRIPTION

Support for computing KMAC MACs through the B<EVP_MAC> API.

=head2 Numeric identity

B<EVP_MAC_KMAC128> and B<EVP_MAC_KMAC256> are the numeric identities for this
implementation, and can be used in functions like EVP_MAC_CTX_new_id() and
EVP_get_macbynid().

=head2 Supported controls

The supported controls are:

=over 4

=item B<EVP_MAC_CTRL_SET_KEY>

This must be set before calling EVP_MAC_init().

EVP_MAC_ctrl_str() takes two type strings for this control:

=over 4

=item "key"

The value string is used as is.

=item "hexkey"

The value string is expected to be a hexadecimal number, which will be
decoded before passing on as control value.

=back

=item B<EVP_MAC_CTRL_SET_CUSTOM>

This is an optional string value that can be set before calling EVP_MAC_init().
If it is not set it uses the default value "".

EVP_MAC_ctrl_str() takes two type strings for this control:

=over 4

=item "custom"

The value string is used as is.

=item "hexcustom"

The value string is expected to be a hexadecimal number, which will be
decoded before passing on as control value.

=back

=item B<EVP_MAC_CTRL_SET_SIZE>

EVP_MAC_ctrl_str() type string: "outlen"

This is an optional value string containing a decimal number. If it is not set
it uses the default value of 32 for EVP_MAC_KMAC128 and 64 for EVP_MAC_KMAC256.
This can be called any time before EVP_MAC_final().

=item B<EVP_MAC_CTRL_SET_XOF>

EVP_MAC_ctrl_str() type string: "xof"

The value string is expected to be an integer value of 1 or 0. Use 1 to enable
XOF mode. If XOF is enabled then the output len that is encoded as part of the
input stream is set to zero.
This can be called any time before EVP_MAC_final().

=back

=head1 SEE ALSO

L<EVP_MAC_ctrl(3)>, L<EVP_MAC(3)/CONTROLS>

=head1 COPYRIGHT

Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut
