/** * \file cmac.h * * \brief This file contains CMAC definitions and functions. * * The Cipher-based Message Authentication Code (CMAC) Mode for * Authentication is defined in RFC-4493: The AES-CMAC Algorithm. * It is supported with AES and DES. */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #ifndef TF_PSA_CRYPTO_MBEDTLS_PRIVATE_CMAC_H #define TF_PSA_CRYPTO_MBEDTLS_PRIVATE_CMAC_H #include "mbedtls/private_access.h" #include "tf-psa-crypto/build_info.h" #include "mbedtls/private/cipher.h" #ifdef __cplusplus extern "C" { #endif #if defined(MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS) #define MBEDTLS_AES_BLOCK_SIZE 16 #define MBEDTLS_DES3_BLOCK_SIZE 8 /* We don't support Camellia or ARIA in this module */ #if defined(MBEDTLS_AES_C) #define MBEDTLS_CMAC_MAX_BLOCK_SIZE 16 /**< The longest block used by CMAC is that of AES. */ #else #define MBEDTLS_CMAC_MAX_BLOCK_SIZE 8 /**< The longest block used by CMAC is that of 3DES. */ #endif /* MBEDTLS_AES_C */ #endif /* MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS */ #if defined(MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS) /** * The CMAC context structure. */ struct mbedtls_cmac_context_t { /** The internal state of the CMAC algorithm. */ unsigned char MBEDTLS_PRIVATE(state)[MBEDTLS_CMAC_MAX_BLOCK_SIZE]; /** Unprocessed data - either data that was not block aligned and is still * pending processing, or the final block. */ unsigned char MBEDTLS_PRIVATE(unprocessed_block)[MBEDTLS_CMAC_MAX_BLOCK_SIZE]; /** The length of data pending processing. */ size_t MBEDTLS_PRIVATE(unprocessed_len); }; /** * \brief This function starts a new CMAC computation * by setting the CMAC key, and preparing to authenticate * the input data. * It must be called with an initialized cipher context. * * Once this function has completed, data can be supplied * to the CMAC computation by calling * mbedtls_cipher_cmac_update(). * * To start a CMAC computation using the same key as a previous * CMAC computation, use mbedtls_cipher_cmac_finish(). * * \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 or MBEDTLS_CIPHER_AES_256_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. * * The CMAC computation must have previously been started * by calling mbedtls_cipher_cmac_starts() or * mbedtls_cipher_cmac_reset(). * * Call this function as many times as needed to input the * data to be authenticated. * Once all of the required data has been input, * call mbedtls_cipher_cmac_finish() to obtain the result * of the CMAC operation. * * \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 an ongoing CMAC operation, and * writes the result to the output buffer. * * It should be followed either by * mbedtls_cipher_cmac_reset(), which starts another CMAC * operation with the same key, or mbedtls_cipher_free(), * which clears the cipher context. * * \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 starts a new CMAC operation with the same * key as the previous one. * * It should be called after finishing the previous CMAC * operation with mbedtls_cipher_cmac_finish(). * After calling this function, * call mbedtls_cipher_cmac_update() to supply the new * CMAC operation with data. * * \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 * 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). * * \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) /** * \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*/ #endif /* MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS */ #ifdef __cplusplus } #endif #endif /* TF_PSA_CRYPTO_MBEDTLS_PRIVATE_CMAC_H */