# EVP_MAC-POLY1305(7SSL) - man - phpMan

[EVP_MAC-POLY1305(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMAC-POLY1305/7SSL/markdown)                         OpenSSL                        [EVP_MAC-POLY1305(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMAC-POLY1305/7SSL/markdown)



## NAME
       EVP_MAC-Poly1305 - The Poly1305 EVP_MAC implementation

## DESCRIPTION
       Support for computing Poly1305 MACs through the **EVP**___**MAC** API.

### Identity
       This implementation is identified with this name and properties, to be used with
       **EVP**___**MAC**___**fetch()**:

       "POLY1305", "provider=default"

### Supported parameters
       The general description of these parameters can be found in "PARAMETERS" in **EVP**___**[MAC**(3)](https://www.chedong.com/phpMan.php/man/MAC/3/markdown).

       The following parameter can be set with **EVP**___**MAC**___**CTX**___**set**___**params()**:

       "key" (**OSSL**___**MAC**___**PARAM**___**KEY**) <octet string>
           Sets the MAC key.  Setting this parameter is identical to passing a _key_ to
           **EVP**___**MAC**___**[init**(3)](https://www.chedong.com/phpMan.php/man/init/3/markdown).

       The following parameters can be retrieved with **EVP**___**MAC**___**CTX**___**get**___**params()**:

       "size" (**OSSL**___**MAC**___**PARAM**___**SIZE**) <unsigned integer>
           Gets the MAC size.

       The "size" parameter can also be retrieved with with **EVP**___**MAC**___**CTX**___**get**___**mac**___**size()**.  The length
       of the "size" parameter should not exceed that of an **unsigned** **int**.

## NOTES
       The OpenSSL implementation of the Poly 1305 MAC corresponds to RFC 7539.

       It is critical to never reuse the key.  The security implication noted in RFC 8439 applies
       equally to the OpenSSL implementation.

## SEE ALSO
       **EVP**___**MAC**___**CTX**___**get**___**[params**(3)](https://www.chedong.com/phpMan.php/man/params/3/markdown), **EVP**___**MAC**___**CTX**___**set**___**[params**(3)](https://www.chedong.com/phpMan.php/man/params/3/markdown), "PARAMETERS" in **EVP**___**[MAC**(3)](https://www.chedong.com/phpMan.php/man/MAC/3/markdown),
       **OSSL**___**[PARAM**(3)](https://www.chedong.com/phpMan.php/man/PARAM/3/markdown)

## COPYRIGHT
       Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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 <<https://www.openssl.org/source/license.html>>.



3.0.2                                        2026-04-07                       [EVP_MAC-POLY1305(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMAC-POLY1305/7SSL/markdown)