/** * \file md.h * * \brief This file contains the generic message-digest wrapper. * * \author Adriaan de Jong */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBEDTLS_MD_H #define MBEDTLS_MD_H #include "mbedtls/private_access.h" #include #include "mbedtls/build_info.h" #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE -0x5080 /**< The selected feature is not available. */ #define MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100 /**< Bad input parameters to function. */ #define MBEDTLS_ERR_MD_ALLOC_FAILED -0x5180 /**< Failed to allocate memory. */ #define MBEDTLS_ERR_MD_FILE_IO_ERROR -0x5200 /**< Opening or reading of file failed. */ #ifdef __cplusplus extern "C" { #endif /** * \brief Supported message digests. * * \warning MD5 and SHA-1 are considered weak message digests and * their use constitutes a security risk. We recommend considering * stronger message digests instead. * */ typedef enum { MBEDTLS_MD_NONE=0, /**< None. */ MBEDTLS_MD_MD5, /**< The MD5 message digest. */ MBEDTLS_MD_SHA1, /**< The SHA-1 message digest. */ MBEDTLS_MD_SHA224, /**< The SHA-224 message digest. */ MBEDTLS_MD_SHA256, /**< The SHA-256 message digest. */ MBEDTLS_MD_SHA384, /**< The SHA-384 message digest. */ MBEDTLS_MD_SHA512, /**< The SHA-512 message digest. */ MBEDTLS_MD_RIPEMD160, /**< The RIPEMD-160 message digest. */ } mbedtls_md_type_t; #if defined(MBEDTLS_SHA512_C) #define MBEDTLS_MD_MAX_SIZE 64 /* longest known is SHA512 */ #else #define MBEDTLS_MD_MAX_SIZE 32 /* longest known is SHA256 or less */ #endif #if defined(MBEDTLS_SHA512_C) #define MBEDTLS_MD_MAX_BLOCK_SIZE 128 #else #define MBEDTLS_MD_MAX_BLOCK_SIZE 64 #endif /** * Opaque struct. * * Constructed using either #mbedtls_md_info_from_string or * #mbedtls_md_info_from_type. * * Fields can be accessed with #mbedtls_md_get_size, * #mbedtls_md_get_type and #mbedtls_md_get_name. */ /* Defined internally in library/md_wrap.h. */ typedef struct mbedtls_md_info_t mbedtls_md_info_t; /** * The generic message-digest context. */ typedef struct mbedtls_md_context_t { /** Information about the associated message digest. */ const mbedtls_md_info_t *MBEDTLS_PRIVATE(md_info); /** The digest-specific context. */ void *MBEDTLS_PRIVATE(md_ctx); /** The HMAC part of the context. */ void *MBEDTLS_PRIVATE(hmac_ctx); } mbedtls_md_context_t; /** * \brief This function returns the list of digests supported by the * generic digest module. * * \note The list starts with the strongest available hashes. * * \return A statically allocated array of digests. Each element * in the returned list is an integer belonging to the * message-digest enumeration #mbedtls_md_type_t. * The last entry is 0. */ const int *mbedtls_md_list( void ); /** * \brief This function returns the message-digest information * associated with the given digest name. * * \param md_name The name of the digest to search for. * * \return The message-digest information associated with \p md_name. * \return NULL if the associated message-digest information is not found. */ const mbedtls_md_info_t *mbedtls_md_info_from_string( const char *md_name ); /** * \brief This function returns the message-digest information * associated with the given digest type. * * \param md_type The type of digest to search for. * * \return The message-digest information associated with \p md_type. * \return NULL if the associated message-digest information is not found. */ const mbedtls_md_info_t *mbedtls_md_info_from_type( mbedtls_md_type_t md_type ); /** * \brief This function initializes a message-digest context without * binding it to a particular message-digest algorithm. * * This function should always be called first. It prepares the * context for mbedtls_md_setup() for binding it to a * message-digest algorithm. */ void mbedtls_md_init( mbedtls_md_context_t *ctx ); /** * \brief This function clears the internal structure of \p ctx and * frees any embedded internal structure, but does not free * \p ctx itself. * * If you have called mbedtls_md_setup() on \p ctx, you must * call mbedtls_md_free() when you are no longer using the * context. * Calling this function if you have previously * called mbedtls_md_init() and nothing else is optional. * You must not call this function if you have not called * mbedtls_md_init(). */ void mbedtls_md_free( mbedtls_md_context_t *ctx ); /** * \brief This function selects the message digest algorithm to use, * and allocates internal structures. * * It should be called after mbedtls_md_init() or * mbedtls_md_free(). Makes it necessary to call * mbedtls_md_free() later. * * \param ctx The context to set up. * \param md_info The information structure of the message-digest algorithm * to use. * \param hmac Defines if HMAC is used. 0: HMAC is not used (saves some memory), * or non-zero: HMAC is used with this context. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. * \return #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure. */ int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac ); /** * \brief This function clones the state of an message-digest * context. * * \note You must call mbedtls_md_setup() on \c dst before calling * this function. * * \note The two contexts must have the same type, * for example, both are SHA-256. * * \warning This function clones the message-digest state, not the * HMAC state. * * \param dst The destination context. * \param src The context to be cloned. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure. */ int mbedtls_md_clone( mbedtls_md_context_t *dst, const mbedtls_md_context_t *src ); /** * \brief This function extracts the message-digest size from the * message-digest information structure. * * \param md_info The information structure of the message-digest algorithm * to use. * * \return The size of the message-digest output in Bytes. */ unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info ); /** * \brief This function extracts the message-digest type from the * message-digest information structure. * * \param md_info The information structure of the message-digest algorithm * to use. * * \return The type of the message digest. */ mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info ); /** * \brief This function extracts the message-digest name from the * message-digest information structure. * * \param md_info The information structure of the message-digest algorithm * to use. * * \return The name of the message digest. */ const char *mbedtls_md_get_name( const mbedtls_md_info_t *md_info ); /** * \brief This function starts a message-digest computation. * * You must call this function after setting up the context * with mbedtls_md_setup(), and before passing data with * mbedtls_md_update(). * * \param ctx The generic message-digest context. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_starts( mbedtls_md_context_t *ctx ); /** * \brief This function feeds an input buffer into an ongoing * message-digest computation. * * You must call mbedtls_md_starts() before calling this * function. You may call this function multiple times. * Afterwards, call mbedtls_md_finish(). * * \param ctx The generic message-digest context. * \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 on parameter-verification * failure. */ int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen ); /** * \brief This function finishes the digest operation, * and writes the result to the output buffer. * * Call this function after a call to mbedtls_md_starts(), * followed by any number of calls to mbedtls_md_update(). * Afterwards, you may either clear the context with * mbedtls_md_free(), or call mbedtls_md_starts() to reuse * the context for another digest operation with the same * algorithm. * * \param ctx The generic message-digest context. * \param output The buffer for the generic message-digest checksum result. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output ); /** * \brief This function calculates the message-digest of a buffer, * with respect to a configurable message-digest algorithm * in a single call. * * The result is calculated as * Output = message_digest(input buffer). * * \param md_info The information structure of the message-digest algorithm * to use. * \param input The buffer holding the data. * \param ilen The length of the input data. * \param output The generic message-digest checksum result. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen, unsigned char *output ); #if defined(MBEDTLS_FS_IO) /** * \brief This function calculates the message-digest checksum * result of the contents of the provided file. * * The result is calculated as * Output = message_digest(file contents). * * \param md_info The information structure of the message-digest algorithm * to use. * \param path The input file name. * \param output The generic message-digest checksum result. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_FILE_IO_ERROR on an I/O error accessing * the file pointed by \p path. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info was NULL. */ int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path, unsigned char *output ); #endif /* MBEDTLS_FS_IO */ /** * \brief This function sets the HMAC key and prepares to * authenticate a new message. * * Call this function after mbedtls_md_setup(), to use * the MD context for an HMAC calculation, then call * mbedtls_md_hmac_update() to provide the input data, and * mbedtls_md_hmac_finish() to get the HMAC value. * * \param ctx The message digest context containing an embedded HMAC * context. * \param key The HMAC secret key. * \param keylen The length of the HMAC key in Bytes. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key, size_t keylen ); /** * \brief This function feeds an input buffer into an ongoing HMAC * computation. * * Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset() * before calling this function. * You may call this function multiple times to pass the * input piecewise. * Afterwards, call mbedtls_md_hmac_finish(). * * \param ctx The message digest context containing an embedded HMAC * context. * \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 on parameter-verification * failure. */ int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen ); /** * \brief This function finishes the HMAC operation, and writes * the result to the output buffer. * * Call this function after mbedtls_md_hmac_starts() and * mbedtls_md_hmac_update() to get the HMAC value. Afterwards * you may either call mbedtls_md_free() to clear the context, * or call mbedtls_md_hmac_reset() to reuse the context with * the same HMAC key. * * \param ctx The message digest context containing an embedded HMAC * context. * \param output The generic HMAC checksum result. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output); /** * \brief This function prepares to authenticate a new message with * the same key as the previous HMAC operation. * * You may call this function after mbedtls_md_hmac_finish(). * Afterwards call mbedtls_md_hmac_update() to pass the new * input. * * \param ctx The message digest context containing an embedded HMAC * context. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx ); /** * \brief This function calculates the full generic HMAC * on the input buffer with the provided key. * * The function allocates the context, performs the * calculation, and frees the context. * * The HMAC result is calculated as * output = generic HMAC(hmac key, input buffer). * * \param md_info The information structure of the message-digest algorithm * to use. * \param key The HMAC secret key. * \param keylen The length of the HMAC secret key in Bytes. * \param input The buffer holding the input data. * \param ilen The length of the input data. * \param output The generic HMAC result. * * \return \c 0 on success. * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification * failure. */ int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen, const unsigned char *input, size_t ilen, unsigned char *output ); /* Internal use */ int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data ); #ifdef __cplusplus } #endif #endif /* MBEDTLS_MD_H */