# man > EVP_MAC-CMAC(7SSL)

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

## NAME
       EVP_MAC-CMAC - The CMAC EVP_MAC implementation

## DESCRIPTION
       Support for computing CMAC MACs through the **EVP_MAC **API.

       This implementation uses EVP_CIPHER functions to get access to the underlying cipher.

### Identity
       This implementation is identified with this name and properties, to be used with
       **EVP_MAC_fetch()**:

       "CMAC", "provider=default" or "provider=fips"

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

       "cipher" (**OSSL_MAC_PARAM_CIPHER**) <UTF8 string>
           Sets the name of the underlying cipher to be used.

       "properties" (**OSSL_MAC_PARAM_PROPERTIES**) <UTF8 string>
           Sets the properties to be queried when trying to fetch the underlying cipher.  This  must
           be given together with the cipher naming parameter to be considered valid.

       The following parameters can be retrieved with **EVP_MAC_CTX_get_params()**:

       "size" (**OSSL_MAC_PARAM_SIZE**) <unsigned integer>
           The  "size"  parameter  can  also be retrieved with with **EVP_MAC_CTX_get_mac_size()**.  The
           length of the "size" parameter is equal to that of an **unsigned int**.

       "block-size" (**OSSL_MAC_PARAM_BLOCK_SIZE**) <unsigned integer>
           Gets the MAC  block  size.   The  "block-size"  parameter  can  also  be  retrieved  with
           **EVP_MAC_CTX_get_block_size()**.

## SEE ALSO
       [**EVP_MAC_CTX_get_params**(3)](https://www.chedong.com/phpMan.php/man/EVPMACCTXgetparams/3/markdown),    [**EVP_MAC_CTX_set_params**(3)](https://www.chedong.com/phpMan.php/man/EVPMACCTXsetparams/3/markdown),    "PARAMETERS"    in    [**EVP_MAC**(3)](https://www.chedong.com/phpMan.php/man/EVPMAC/3/markdown),
       [**OSSL_PARAM**(3)](https://www.chedong.com/phpMan.php/man/OSSLPARAM/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>>.

3.0.13                                       2026-07-29                           [_EVP_MAC-CMAC_(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMAC-CMAC/7SSL/markdown)