# EVP_MAC-Siphash(7ssl) - man - phpman

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



## NAME
       EVP_MAC-Siphash - The Siphash EVP_MAC implementation

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

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

       "SIPHASH", "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).

       All these parameters can be set with **EVP**___**MAC**___**CTX**___**set**___**params()**.  Furthermore, the "size"
       parameter can be retrieved with **EVP**___**MAC**___**CTX**___**get**___**params()**, or with **EVP**___**MAC**___**CTX**___**get**___**mac**___**size()**.
       The length of the "size" parameter should not exceed that of a **size**___**t**.

       "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).

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

       "c-rounds" (**OSSL**___**MAC**___**PARAM**___**C**___**ROUNDS**) <unsigned integer>
           Specifies the number of rounds per message block.  By default this is _2_.

       "d-rounds" (**OSSL**___**MAC**___**PARAM**___**D**___**ROUNDS**) <unsigned integer>
           Specifies the number of finalisation rounds.  By default this is _4_.

## 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-SIPHASH(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMAC-SIPHASH/7SSL/markdown)