Android_verify/third_party/android-libs/share/man/man7/EVP_MAC-Poly1305.7ossl

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.\"
.IX Title "EVP_MAC-POLY1305 7ossl"
.TH EVP_MAC-POLY1305 7ossl "2024-09-03" "3.3.2" "OpenSSL"
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.nh
.SH "NAME"
EVP_MAC\-Poly1305 \- The Poly1305 EVP_MAC implementation
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Support for computing Poly1305 MACs through the \fB\s-1EVP_MAC\s0\fR \s-1API.\s0
.SS "Identity"
.IX Subsection "Identity"
This implementation is identified with this name and properties, to be
used with \fBEVP_MAC_fetch()\fR:
.ie n .IP """\s-1POLY1305"",\s0 ""provider=default""" 4
.el .IP "``\s-1POLY1305'',\s0 ``provider=default''" 4
.IX Item "POLY1305, provider=default"
.SS "Supported parameters"
.IX Subsection "Supported parameters"
The general description of these parameters can be found in
\&\*(L"\s-1PARAMETERS\*(R"\s0 in \s-1\fBEVP_MAC\s0\fR\|(3).
.PP
The following parameter can be set with \fBEVP_MAC_CTX_set_params()\fR:
.ie n .IP """key"" (\fB\s-1OSSL_MAC_PARAM_KEY\s0\fR) <octet string>" 4
.el .IP "``key'' (\fB\s-1OSSL_MAC_PARAM_KEY\s0\fR) <octet string>" 4
.IX Item "key (OSSL_MAC_PARAM_KEY) <octet string>"
Sets the \s-1MAC\s0 key.
Setting this parameter is identical to passing a \fIkey\fR to \fBEVP_MAC_init\fR\|(3).
.PP
The following parameters can be retrieved with
\&\fBEVP_MAC_CTX_get_params()\fR:
.ie n .IP """size"" (\fB\s-1OSSL_MAC_PARAM_SIZE\s0\fR) <unsigned integer>" 4
.el .IP "``size'' (\fB\s-1OSSL_MAC_PARAM_SIZE\s0\fR) <unsigned integer>" 4
.IX Item "size (OSSL_MAC_PARAM_SIZE) <unsigned integer>"
Gets the \s-1MAC\s0 size.
.PP
The \*(L"size\*(R" parameter can also be retrieved with with \fBEVP_MAC_CTX_get_mac_size()\fR.
The length of the \*(L"size\*(R" parameter should not exceed that of an \fBunsigned int\fR.
.SH "NOTES"
.IX Header "NOTES"
The OpenSSL implementation of the Poly 1305 \s-1MAC\s0 corresponds to \s-1RFC 7539.\s0
.PP
It is critical to never reuse the key.  The security implication noted in
\&\s-1RFC 8439\s0 applies equally to the OpenSSL implementation.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBEVP_MAC_CTX_get_params\fR\|(3), \fBEVP_MAC_CTX_set_params\fR\|(3),
\&\*(L"\s-1PARAMETERS\*(R"\s0 in \s-1\fBEVP_MAC\s0\fR\|(3), \s-1\fBOSSL_PARAM\s0\fR\|(3)
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2018\-2021 The OpenSSL Project Authors. All Rights Reserved.
.PP
Licensed under the Apache License 2.0 (the \*(L"License\*(R").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file \s-1LICENSE\s0 in the source distribution or at
<https://www.openssl.org/source/license.html>.