/**
* \file cmac.h
*
* \brief This file contains CMAC definitions and functions.
*
* The Cipher-based Message Authentication Code (CMAC) Mode for
* Authentication is defined in <em>RFC-4493: The AES-CMAC Algorithm</em>.
*/
/*
* Copyright (C) 2015-2018, Arm Limited (or its affiliates), All Rights Reserved
* SPDX-License-Identifier: GPL-2.0
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This file is part of Mbed TLS (https://tls.mbed.org)
*/
#ifndef MBEDTLS_CMAC_H
#define MBEDTLS_CMAC_H
#include "cipher.h"
#ifdef __cplusplus
extern "C" {
#endif
#define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A /**< CMAC hardware accelerator failed. */
#define MBEDTLS_AES_BLOCK_SIZE 16
#define MBEDTLS_DES3_BLOCK_SIZE 8
#if defined(MBEDTLS_AES_C)
#define MBEDTLS_CIPHER_BLKSIZE_MAX 16 /**< The longest block used by CMAC is that of AES. */
#else
#define MBEDTLS_CIPHER_BLKSIZE_MAX 8 /**< The longest block used by CMAC is that of 3DES. */
#endif
#if !defined(MBEDTLS_CMAC_ALT)
/**
* The CMAC context structure.
*/
struct mbedtls_cmac_context_t {
/** The internal state of the CMAC algorithm. */
unsigned char state[MBEDTLS_CIPHER_BLKSIZE_MAX];
/** Unprocessed data - either data that was not block aligned and is still
* pending processing, or the final block. */
unsigned char unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX];
/** The length of data pending processing. */
size_t unprocessed_len;
};
#else /* !MBEDTLS_CMAC_ALT */
#include "cmac_alt.h"
#endif /* !MBEDTLS_CMAC_ALT */
/**
* \brief This function sets the CMAC key, and prepares to authenticate
* the input data.
* Must be called with an initialized cipher context.
*
* \param ctx The cipher context used for the CMAC operation, initialized
* as one of the following types: MBEDTLS_CIPHER_AES_128_ECB,
* MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB,
* or MBEDTLS_CIPHER_DES_EDE3_ECB.
* \param key The CMAC key.
* \param keybits The length of the CMAC key in bits.
* Must be supported by the cipher.
*
* \return \c 0 on success.
* \return A cipher-specific error code on failure.
*/
int mbedtls_cipher_cmac_starts(mbedtls_cipher_context_t *ctx,
const unsigned char *key, size_t keybits);
/**
* \brief This function feeds an input buffer into an ongoing CMAC
* computation.
*
* It is called between mbedtls_cipher_cmac_starts() or
* mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish().
* Can be called repeatedly.
*
* \param ctx The cipher context used for the CMAC operation.
* \param input The buffer holding the input data.
* \param ilen The length of the input data.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
* if parameter verification fails.
*/
int mbedtls_cipher_cmac_update(mbedtls_cipher_context_t *ctx,
const unsigned char *input, size_t ilen);
/**
* \brief This function finishes the CMAC operation, and writes
* the result to the output buffer.
*
* It is called after mbedtls_cipher_cmac_update().
* It can be followed by mbedtls_cipher_cmac_reset() and
* mbedtls_cipher_cmac_update(), or mbedtls_cipher_free().
*
* \param ctx The cipher context used for the CMAC operation.
* \param output The output buffer for the CMAC checksum result.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
* if parameter verification fails.
*/
int mbedtls_cipher_cmac_finish(mbedtls_cipher_context_t *ctx,
unsigned char *output);
/**
* \brief This function prepares the authentication of another
* message with the same key as the previous CMAC
* operation.
*
* It is called after mbedtls_cipher_cmac_finish()
* and before mbedtls_cipher_cmac_update().
*
* \param ctx The cipher context used for the CMAC operation.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
* if parameter verification fails.
*/
int mbedtls_cipher_cmac_reset(mbedtls_cipher_context_t *ctx);
/**
* \brief This function calculates the full generic CMAC
* on the input buffer with the provided key.
*
* The function allocates the context, performs the
* calculation, and frees the context.
*
* The CMAC result is calculated as
* output = generic CMAC(cmac key, input buffer).
*
*
* \param cipher_info The cipher information.
* \param key The CMAC key.
* \param keylen The length of the CMAC key in bits.
* \param input The buffer holding the input data.
* \param ilen The length of the input data.
* \param output The buffer for the generic CMAC result.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
* if parameter verification fails.
*/
int mbedtls_cipher_cmac(const mbedtls_cipher_info_t *cipher_info,
const unsigned char *key, size_t keylen,
const unsigned char *input, size_t ilen,
unsigned char *output);
#if defined(MBEDTLS_AES_C)
/**
* \brief This function implements the AES-CMAC-PRF-128 pseudorandom
* function, as defined in
* <em>RFC-4615: The Advanced Encryption Standard-Cipher-based
* Message Authentication Code-Pseudo-Random Function-128
* (AES-CMAC-PRF-128) Algorithm for the Internet Key
* Exchange Protocol (IKE).</em>
*
* \param key The key to use.
* \param key_len The key length in Bytes.
* \param input The buffer holding the input data.
* \param in_len The length of the input data in Bytes.
* \param output The buffer holding the generated 16 Bytes of
* pseudorandom output.
*
* \return \c 0 on success.
*/
int mbedtls_aes_cmac_prf_128(const unsigned char *key, size_t key_len,
const unsigned char *input, size_t in_len,
unsigned char output[16]);
#endif /* MBEDTLS_AES_C */
#if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) )
/**
* \brief The CMAC checkup routine.
*
* \return \c 0 on success.
* \return \c 1 on failure.
*/
int mbedtls_cmac_self_test(int verbose);
#endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_CMAC_H */