xref: /openssl/doc/man7/EVP_MAC-Poly1305.pod (revision bbf5ccfd)
1=pod
2
3=head1 NAME
4
5EVP_MAC-Poly1305 - The Poly1305 EVP_MAC implementation
6
7=head1 DESCRIPTION
8
9Support for computing Poly1305 MACs through the B<EVP_MAC> API.
10
11=head2 Identity
12
13This implementation is identified with this name and properties, to be
14used with EVP_MAC_fetch():
15
16=over 4
17
18=item "POLY1305", "provider=default"
19
20=back
21
22=head2 Supported parameters
23
24The general description of these parameters can be found in
25L<EVP_MAC(3)/PARAMETERS>.
26
27The following parameter can be set with EVP_MAC_CTX_set_params():
28
29=over 4
30
31=item "key" (B<OSSL_MAC_PARAM_KEY>) <octet string>
32
33Sets the MAC key.
34Setting this parameter is identical to passing a I<key> to L<EVP_MAC_init(3)>.
35
36=back
37
38The following parameters can be retrieved with
39EVP_MAC_CTX_get_params():
40
41=over 4
42
43=item "size" (B<OSSL_MAC_PARAM_SIZE>) <unsigned integer>
44
45Gets the MAC size.
46
47=back
48
49The "size" parameter can also be retrieved with with EVP_MAC_CTX_get_mac_size().
50The length of the "size" parameter should not exceed that of an B<unsigned int>.
51
52=head1 NOTES
53
54The OpenSSL implementation of the Poly 1305 MAC corresponds to RFC 7539.
55
56It is critical to never reuse the key.  The security implication noted in
57RFC 8439 applies equally to the OpenSSL implementation.
58
59=head1 SEE ALSO
60
61L<EVP_MAC_CTX_get_params(3)>, L<EVP_MAC_CTX_set_params(3)>,
62L<EVP_MAC(3)/PARAMETERS>, L<OSSL_PARAM(3)>
63
64=head1 COPYRIGHT
65
66Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.
67
68Licensed under the Apache License 2.0 (the "License").  You may not use
69this file except in compliance with the License.  You can obtain a copy
70in the file LICENSE in the source distribution or at
71L<https://www.openssl.org/source/license.html>.
72
73=cut
74