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).

       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).

       "cipher" (OSSL_MAC_PARAM_CIPHER) <UTF8 string>
           Sets the name of the underlying cipher to be used. The mode of the cipher must be CBC.

       "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.

       "encrypt-check" (OSSL_CIPHER_PARAM_FIPS_ENCRYPT_CHECK) <integer>
           This option is used by the OpenSSL FIPS provider.  If required this parameter should  be  set  before
           EVP_MAC_init()

           The  default  value  of  1  causes  an  error  when  a  unapproved Triple-DES encryption operation is
           triggered.  Setting this to 0 will ignore the error and set the approved "fips-indicator" to 0.  This
           option breaks FIPS compliance if it causes the approved "fips-indicator" to return 0.

       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().

       "fips-indicator" (OSSL_CIPHER_PARAM_FIPS_APPROVED_INDICATOR) <integer>
           This option is used by the OpenSSL FIPS provider.

           A getter that returns 1 if the operation is FIPS approved, or 0 otherwise.  This may  be  used  after
           calling EVP_MAC_final().  It may return 0 if the "encrypt-check" option is set to 0.

SEE ALSO

       EVP_MAC_CTX_get_params(3), EVP_MAC_CTX_set_params(3), "PARAMETERS" in EVP_MAC(3), OSSL_PARAM(3)

COPYRIGHT

       Copyright 2018-2024 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>.

3.5.0                                              2025-06-04                                 EVP_MAC-CMAC(7SSL)