1 /** 2 * \file md.h 3 * 4 * \brief This file contains the generic message-digest wrapper. 5 * 6 * \author Adriaan de Jong <dejong@fox-it.com> 7 */ 8 /* 9 * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved 10 * Copyright (C) 2018-2022, Intel Corporation. 11 * SPDX-License-Identifier: Apache-2.0 12 * 13 * Licensed under the Apache License, Version 2.0 (the "License"); you may 14 * not use this file except in compliance with the License. 15 * You may obtain a copy of the License at 16 * 17 * http://www.apache.org/licenses/LICENSE-2.0 18 * 19 * Unless required by applicable law or agreed to in writing, software 20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 22 * See the License for the specific language governing permissions and 23 * limitations under the License. 24 * 25 * This file is part of Mbed TLS (https://tls.mbed.org) 26 */ 27 28 #ifndef MBEDTLS_MD_H 29 #define MBEDTLS_MD_H 30 31 #include <rtl.h> 32 #include "sha256.h" 33 34 #define MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100 /**< Bad input parameters to function. */ 35 36 #define mbedtls_platform_zeroize(buf, len) memset((buf), 0U, (len)) 37 38 /** 39 * \brief Supported message digests. 40 * 41 */ 42 typedef enum { 43 MBEDTLS_MD_NONE = 0, /**< None. */ 44 MBEDTLS_MD_SHA256, /**< The SHA-256 message digest. */ 45 } mbedtls_md_type_t; 46 47 #define MBEDTLS_MD_MAX_SIZE 32 /* longest known is SHA256 or less */ 48 49 /** 50 * Opaque struct defined in md_internal.h. 51 */ 52 typedef struct mbedtls_md_info mbedtls_md_info_t; 53 54 /** 55 * The generic message-digest context. 56 */ 57 typedef struct { 58 /** Information about the associated message digest. */ 59 const mbedtls_md_info_t *md_info; 60 61 /** The digest-specific context. */ 62 uint8_t md_ctx[sizeof(mbedtls_sha256_context)]; 63 64 /** The HMAC part of the context. Use array here to avoid dynamic memory 65 * allocation. The hardcode value 128 is 2 times of block_size which 66 * is 64 in md_wrap.c 67 */ 68 uint8_t hmac_ctx[128]; 69 } mbedtls_md_context_t; 70 71 /** 72 * \brief This function returns the message-digest information 73 * associated with the given digest type. 74 * 75 * \param md_type The type of digest to search for. 76 * 77 * \return The message-digest information associated with \p md_type. 78 * \return NULL if the associated message-digest information is not found. 79 */ 80 const mbedtls_md_info_t *mbedtls_md_info_from_type(mbedtls_md_type_t md_type); 81 82 /** 83 * \brief This function initializes a message-digest context without 84 * binding it to a particular message-digest algorithm. 85 * 86 * This function should always be called first. It prepares the 87 * context for mbedtls_md_setup() for binding it to a 88 * message-digest algorithm. 89 */ 90 void mbedtls_md_init(mbedtls_md_context_t *ctx); 91 92 /** 93 * \brief This function clears the internal structure of \p ctx and 94 * frees any embedded internal structure, but does not free 95 * \p ctx itself. 96 * 97 * If you have called mbedtls_md_setup() on \p ctx, you must 98 * call mbedtls_md_free() when you are no longer using the 99 * context. 100 * Calling this function if you have previously 101 * called mbedtls_md_init() and nothing else is optional. 102 * You must not call this function if you have not called 103 * mbedtls_md_init(). 104 */ 105 void mbedtls_md_free(mbedtls_md_context_t *ctx); 106 107 /** 108 * \brief This function selects the message digest algorithm to use, 109 * and allocates internal structures. 110 * 111 * It should be called after mbedtls_md_init() or 112 * mbedtls_md_free(). Makes it necessary to call 113 * mbedtls_md_free() later. 114 * 115 * \param ctx The context to set up. 116 * \param md_info The information structure of the message-digest algorithm 117 * to use. 118 * 119 * \return \c 0 on success. 120 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 121 * failure. 122 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure. 123 */ 124 int32_t mbedtls_md_setup(mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info); 125 126 /** 127 * \brief This function extracts the message-digest size from the 128 * message-digest information structure. 129 * 130 * \param md_info The information structure of the message-digest algorithm 131 * to use. 132 * 133 * \return The size of the message-digest output in Bytes. 134 */ 135 uint8_t mbedtls_md_get_size(const mbedtls_md_info_t *md_info); 136 137 /** 138 * \brief This function sets the HMAC key and prepares to 139 * authenticate a new message. 140 * 141 * Call this function after mbedtls_md_setup(), to use 142 * the MD context for an HMAC calculation, then call 143 * mbedtls_md_hmac_update() to provide the input data, and 144 * mbedtls_md_hmac_finish() to get the HMAC value. 145 * 146 * \param ctx The message digest context containing an embedded HMAC 147 * context. 148 * \param key The HMAC secret key. 149 * \param keylen The length of the HMAC key in Bytes. 150 * 151 * \return \c 0 on success. 152 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 153 * failure. 154 */ 155 int32_t mbedtls_md_hmac_starts(mbedtls_md_context_t *ctx, const uint8_t *key, size_t keylen); 156 157 /** 158 * \brief This function feeds an input buffer into an ongoing HMAC 159 * computation. 160 * 161 * Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset() 162 * before calling this function. 163 * You may call this function multiple times to pass the 164 * input piecewise. 165 * Afterwards, call mbedtls_md_hmac_finish(). 166 * 167 * \param ctx The message digest context containing an embedded HMAC 168 * context. 169 * \param input The buffer holding the input data. 170 * \param ilen The length of the input data. 171 * 172 * \return \c 0 on success. 173 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 174 * failure. 175 */ 176 int32_t mbedtls_md_hmac_update(mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen); 177 178 /** 179 * \brief This function finishes the HMAC operation, and writes 180 * the result to the output buffer. 181 * 182 * Call this function after mbedtls_md_hmac_starts() and 183 * mbedtls_md_hmac_update() to get the HMAC value. Afterwards 184 * you may either call mbedtls_md_free() to clear the context, 185 * or call mbedtls_md_hmac_reset() to reuse the context with 186 * the same HMAC key. 187 * 188 * \param ctx The message digest context containing an embedded HMAC 189 * context. 190 * \param output The generic HMAC checksum result. 191 * 192 * \return \c 0 on success. 193 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 194 * failure. 195 */ 196 int32_t mbedtls_md_hmac_finish(mbedtls_md_context_t *ctx, uint8_t *output); 197 198 /** 199 * \brief This function calculates the full generic HMAC 200 * on the input buffer with the provided key. 201 * 202 * The function allocates the context, performs the 203 * calculation, and frees the context. 204 * 205 * The HMAC result is calculated as 206 * output = generic HMAC(hmac key, input buffer). 207 * 208 * \param md_info The information structure of the message-digest algorithm 209 * to use. 210 * \param key The HMAC secret key. 211 * \param keylen The length of the HMAC secret key in Bytes. 212 * \param input The buffer holding the input data. 213 * \param ilen The length of the input data. 214 * \param output The generic HMAC result. 215 * 216 * \return \c 0 on success. 217 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 218 * failure. 219 */ 220 int32_t mbedtls_md_hmac(const mbedtls_md_info_t *md_info, const uint8_t *key, size_t keylen, 221 const uint8_t *input, size_t ilen, uint8_t *output); 222 223 #endif /* MBEDTLS_MD_H */ 224