EVP_MAC-CMAC7ssl
The cmac evp_mac implementation
Overview
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_MAC_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.
Releases
3 releases since Debian 12 (Bookworm); the text changed 2 times.