ica_des_cmac

Purpose

Authenticate data or verify the authenticity of data with a DES key using the Block Cipher Based Message Authentication Code (CMAC) mode, as described in NIST Special Publication 800-38B. ica_des_cmac can be used to authenticate or verify the authenticity of a complete message.

Format


unsigned int ica_des_cmac(const unsigned char *message,
  unsigned long message_length,
  unsigned char *mac,
  unsigned int mac_length,
  const unsigned char *key,
  unsigned int direction);

Required hardware support

KMAC-DEA
PCC-Compute-Last_block-CMAC-Using-DEA

Parameters

const unsigned char *message

Pointer to a readable buffer of size greater than or equal to message_length bytes. This buffer contains a message to be authenticated or of which the authenticity is to be verified.

unsigned long message_length

Length in bytes of the message to be authenticated or verified.

unsigned char *mac

Pointer to a buffer of size greater than or equal to mac_length bytes. If direction is equal to 1, the buffer must be writable and a message authentication code for the message in message of size mac_length bytes is written to the buffer. If direction is equal to 0, the buffer must be readable and contain a message authentication code to be verified against the message in message.

unsigned int mac_length

Length in bytes of the message authentication code mac, which is less than or equal to the cipher block size (8 bytes for DES). It is recommended to use a mac_length of 8.

const unsigned char *key

Pointer to a valid DES key of 8 bytes in length.

unsigned int direction

0: Verify message authentication code.
1: Compute message authentication code for the message.

Return codes

0: Success
EFAULT: If direction is equal to 0 and the verification of the message authentication code fails.

For return codes indicating exceptions, see Return codes.