cmac.h

00001 /**
00002  * \file cmac.h
00003  *
00004  * \brief This file contains CMAC definitions and functions.
00005  *
00006  * The Cipher-based Message Authentication Code (CMAC) Mode for
00007  * Authentication is defined in <em>RFC-4493: The AES-CMAC Algorithm</em>.
00008  */
00009 /*
00010  *  Copyright (C) 2015-2018, Arm Limited (or its affiliates), All Rights Reserved
00011  *  SPDX-License-Identifier: Apache-2.0
00012  *
00013  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00014  *  not use this file except in compliance with the License.
00015  *  You may obtain a copy of the License at
00016  *
00017  *  http://www.apache.org/licenses/LICENSE-2.0
00018  *
00019  *  Unless required by applicable law or agreed to in writing, software
00020  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00021  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00022  *  See the License for the specific language governing permissions and
00023  *  limitations under the License.
00024  *
00025  *  This file is part of Mbed TLS (https://tls.mbed.org)
00026  */
00027 
00028 #ifndef MBEDTLS_CMAC_H
00029 #define MBEDTLS_CMAC_H
00030 
00031 #include "cipher.h"
00032 
00033 #ifdef __cplusplus
00034 extern "C" {
00035 #endif
00036 
00037 #define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A  /**< CMAC hardware accelerator failed. */
00038 
00039 #define MBEDTLS_AES_BLOCK_SIZE          16
00040 #define MBEDTLS_DES3_BLOCK_SIZE         8
00041 
00042 #if defined(MBEDTLS_AES_C)
00043 #define MBEDTLS_CIPHER_BLKSIZE_MAX      16  /**< The longest block used by CMAC is that of AES. */
00044 #else
00045 #define MBEDTLS_CIPHER_BLKSIZE_MAX      8   /**< The longest block used by CMAC is that of 3DES. */
00046 #endif
00047 
00048 #if !defined(MBEDTLS_CMAC_ALT)
00049 
00050 /**
00051  * The CMAC context structure.
00052  */
00053 struct mbedtls_cmac_context_t
00054 {
00055     /** The internal state of the CMAC algorithm.  */
00056     unsigned char       state[MBEDTLS_CIPHER_BLKSIZE_MAX];
00057 
00058     /** Unprocessed data - either data that was not block aligned and is still
00059      *  pending processing, or the final block. */
00060     unsigned char       unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX];
00061 
00062     /** The length of data pending processing. */
00063     size_t              unprocessed_len;
00064 };
00065 
00066 #else  /* !MBEDTLS_CMAC_ALT */
00067 #include "cmac_alt.h"
00068 #endif /* !MBEDTLS_CMAC_ALT */
00069 
00070 /**
00071  * \brief               This function sets the CMAC key, and prepares to authenticate
00072  *                      the input data.
00073  *                      Must be called with an initialized cipher context.
00074  *
00075  * \param ctx           The cipher context used for the CMAC operation, initialized
00076  *                      as one of the following types: MBEDTLS_CIPHER_AES_128_ECB,
00077  *                      MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB,
00078  *                      or MBEDTLS_CIPHER_DES_EDE3_ECB.
00079  * \param key           The CMAC key.
00080  * \param keybits       The length of the CMAC key in bits.
00081  *                      Must be supported by the cipher.
00082  *
00083  * \return              \c 0 on success.
00084  * \return              A cipher-specific error code on failure.
00085  */
00086 int mbedtls_cipher_cmac_starts( mbedtls_cipher_context_t *ctx,
00087                                 const unsigned char *key, size_t keybits );
00088 
00089 /**
00090  * \brief               This function feeds an input buffer into an ongoing CMAC
00091  *                      computation.
00092  *
00093  *                      It is called between mbedtls_cipher_cmac_starts() or
00094  *                      mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish().
00095  *                      Can be called repeatedly.
00096  *
00097  * \param ctx           The cipher context used for the CMAC operation.
00098  * \param input         The buffer holding the input data.
00099  * \param ilen          The length of the input data.
00100  *
00101  * \return             \c 0 on success.
00102  * \return             #MBEDTLS_ERR_MD_BAD_INPUT_DATA
00103  *                     if parameter verification fails.
00104  */
00105 int mbedtls_cipher_cmac_update( mbedtls_cipher_context_t *ctx,
00106                                 const unsigned char *input, size_t ilen );
00107 
00108 /**
00109  * \brief               This function finishes the CMAC operation, and writes
00110  *                      the result to the output buffer.
00111  *
00112  *                      It is called after mbedtls_cipher_cmac_update().
00113  *                      It can be followed by mbedtls_cipher_cmac_reset() and
00114  *                      mbedtls_cipher_cmac_update(), or mbedtls_cipher_free().
00115  *
00116  * \param ctx           The cipher context used for the CMAC operation.
00117  * \param output        The output buffer for the CMAC checksum result.
00118  *
00119  * \return              \c 0 on success.
00120  * \return              #MBEDTLS_ERR_MD_BAD_INPUT_DATA
00121  *                      if parameter verification fails.
00122  */
00123 int mbedtls_cipher_cmac_finish( mbedtls_cipher_context_t *ctx,
00124                                 unsigned char *output );
00125 
00126 /**
00127  * \brief               This function prepares the authentication of another
00128  *                      message with the same key as the previous CMAC
00129  *                      operation.
00130  *
00131  *                      It is called after mbedtls_cipher_cmac_finish()
00132  *                      and before mbedtls_cipher_cmac_update().
00133  *
00134  * \param ctx           The cipher context used for the CMAC operation.
00135  *
00136  * \return              \c 0 on success.
00137  * \return              #MBEDTLS_ERR_MD_BAD_INPUT_DATA
00138  *                      if parameter verification fails.
00139  */
00140 int mbedtls_cipher_cmac_reset( mbedtls_cipher_context_t *ctx );
00141 
00142 /**
00143  * \brief               This function calculates the full generic CMAC
00144  *                      on the input buffer with the provided key.
00145  *
00146  *                      The function allocates the context, performs the
00147  *                      calculation, and frees the context.
00148  *
00149  *                      The CMAC result is calculated as
00150  *                      output = generic CMAC(cmac key, input buffer).
00151  *
00152  *
00153  * \param cipher_info   The cipher information.
00154  * \param key           The CMAC key.
00155  * \param keylen        The length of the CMAC key in bits.
00156  * \param input         The buffer holding the input data.
00157  * \param ilen          The length of the input data.
00158  * \param output        The buffer for the generic CMAC result.
00159  *
00160  * \return              \c 0 on success.
00161  * \return              #MBEDTLS_ERR_MD_BAD_INPUT_DATA
00162  *                      if parameter verification fails.
00163  */
00164 int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info,
00165                          const unsigned char *key, size_t keylen,
00166                          const unsigned char *input, size_t ilen,
00167                          unsigned char *output );
00168 
00169 #if defined(MBEDTLS_AES_C)
00170 /**
00171  * \brief           This function implements the AES-CMAC-PRF-128 pseudorandom
00172  *                  function, as defined in
00173  *                  <em>RFC-4615: The Advanced Encryption Standard-Cipher-based
00174  *                  Message Authentication Code-Pseudo-Random Function-128
00175  *                  (AES-CMAC-PRF-128) Algorithm for the Internet Key
00176  *                  Exchange Protocol (IKE).</em>
00177  *
00178  * \param key       The key to use.
00179  * \param key_len   The key length in Bytes.
00180  * \param input     The buffer holding the input data.
00181  * \param in_len    The length of the input data in Bytes.
00182  * \param output    The buffer holding the generated 16 Bytes of
00183  *                  pseudorandom output.
00184  *
00185  * \return          \c 0 on success.
00186  */
00187 int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len,
00188                               const unsigned char *input, size_t in_len,
00189                               unsigned char output[16] );
00190 #endif /* MBEDTLS_AES_C */
00191 
00192 #if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) )
00193 /**
00194  * \brief          The CMAC checkup routine.
00195  *
00196  * \return         \c 0 on success.
00197  * \return         \c 1 on failure.
00198  */
00199 int mbedtls_cmac_self_test( int verbose );
00200 #endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
00201 
00202 #ifdef __cplusplus
00203 }
00204 #endif
00205 
00206 #endif /* MBEDTLS_CMAC_H */