1 /** 2 * \file sha256.h 3 * 4 * \brief This file contains SHA-224 and SHA-256 definitions and functions. 5 * 6 * The Secure Hash Algorithms 224 and 256 (SHA-224 and SHA-256) cryptographic 7 * hash functions are defined in <em>FIPS 180-4: Secure Hash Standard (SHS)</em>. 8 */ 9 /* 10 * Copyright The Mbed TLS Contributors 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 #ifndef MBEDTLS_SHA256_H 26 #define MBEDTLS_SHA256_H 27 #include "mbedtls/private_access.h" 28 29 #include "mbedtls/build_info.h" 30 31 #include <stddef.h> 32 #include <stdint.h> 33 34 /** SHA-256 input data was malformed. */ 35 #define MBEDTLS_ERR_SHA256_BAD_INPUT_DATA -0x0074 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 #if !defined(MBEDTLS_SHA256_ALT) 42 // Regular implementation 43 // 44 45 /** 46 * \brief The SHA-256 context structure. 47 * 48 * The structure is used both for SHA-256 and for SHA-224 49 * checksum calculations. The choice between these two is 50 * made in the call to mbedtls_sha256_starts(). 51 */ 52 typedef struct mbedtls_sha256_context { 53 uint32_t MBEDTLS_PRIVATE(total)[2]; /*!< The number of Bytes processed. */ 54 uint32_t MBEDTLS_PRIVATE(state)[8]; /*!< The intermediate digest state. */ 55 unsigned char MBEDTLS_PRIVATE(buffer)[64]; /*!< The data block being processed. */ 56 int MBEDTLS_PRIVATE(is224); /*!< Determines which function to use: 57 0: Use SHA-256, or 1: Use SHA-224. */ 58 } 59 mbedtls_sha256_context; 60 61 #else /* MBEDTLS_SHA256_ALT */ 62 #include "sha256_alt.h" 63 #endif /* MBEDTLS_SHA256_ALT */ 64 65 /** 66 * \brief This function initializes a SHA-256 context. 67 * 68 * \param ctx The SHA-256 context to initialize. This must not be \c NULL. 69 */ 70 void mbedtls_sha256_init(mbedtls_sha256_context *ctx); 71 72 /** 73 * \brief This function clears a SHA-256 context. 74 * 75 * \param ctx The SHA-256 context to clear. This may be \c NULL, in which 76 * case this function returns immediately. If it is not \c NULL, 77 * it must point to an initialized SHA-256 context. 78 */ 79 void mbedtls_sha256_free(mbedtls_sha256_context *ctx); 80 81 /** 82 * \brief This function clones the state of a SHA-256 context. 83 * 84 * \param dst The destination context. This must be initialized. 85 * \param src The context to clone. This must be initialized. 86 */ 87 void mbedtls_sha256_clone(mbedtls_sha256_context *dst, 88 const mbedtls_sha256_context *src); 89 90 /** 91 * \brief This function starts a SHA-224 or SHA-256 checksum 92 * calculation. 93 * 94 * \param ctx The context to use. This must be initialized. 95 * \param is224 This determines which function to use. This must be 96 * either \c 0 for SHA-256, or \c 1 for SHA-224. 97 * 98 * \note is224 must be defined accordingly to the enabled 99 * MBEDTLS_SHA224_C/MBEDTLS_SHA256_C symbols otherwise the 100 * function will return #MBEDTLS_ERR_SHA512_BAD_INPUT_DATA. 101 * 102 * \return \c 0 on success. 103 * \return A negative error code on failure. 104 */ 105 int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224); 106 107 /** 108 * \brief This function feeds an input buffer into an ongoing 109 * SHA-256 checksum calculation. 110 * 111 * \param ctx The SHA-256 context. This must be initialized 112 * and have a hash operation started. 113 * \param input The buffer holding the data. This must be a readable 114 * buffer of length \p ilen Bytes. 115 * \param ilen The length of the input data in Bytes. 116 * 117 * \return \c 0 on success. 118 * \return A negative error code on failure. 119 */ 120 int mbedtls_sha256_update(mbedtls_sha256_context *ctx, 121 const unsigned char *input, 122 size_t ilen); 123 124 /** 125 * \brief This function finishes the SHA-256 operation, and writes 126 * the result to the output buffer. 127 * 128 * \param ctx The SHA-256 context. This must be initialized 129 * and have a hash operation started. 130 * \param output The SHA-224 or SHA-256 checksum result. 131 * This must be a writable buffer of length \c 32 bytes 132 * for SHA-256, \c 28 bytes for SHA-224. 133 * 134 * \return \c 0 on success. 135 * \return A negative error code on failure. 136 */ 137 int mbedtls_sha256_finish(mbedtls_sha256_context *ctx, 138 unsigned char *output); 139 140 /** 141 * \brief This function processes a single data block within 142 * the ongoing SHA-256 computation. This function is for 143 * internal use only. 144 * 145 * \param ctx The SHA-256 context. This must be initialized. 146 * \param data The buffer holding one block of data. This must 147 * be a readable buffer of length \c 64 Bytes. 148 * 149 * \return \c 0 on success. 150 * \return A negative error code on failure. 151 */ 152 int mbedtls_internal_sha256_process(mbedtls_sha256_context *ctx, 153 const unsigned char data[64]); 154 155 /** 156 * \brief This function calculates the SHA-224 or SHA-256 157 * checksum of a buffer. 158 * 159 * The function allocates the context, performs the 160 * calculation, and frees the context. 161 * 162 * The SHA-256 result is calculated as 163 * output = SHA-256(input buffer). 164 * 165 * \param input The buffer holding the data. This must be a readable 166 * buffer of length \p ilen Bytes. 167 * \param ilen The length of the input data in Bytes. 168 * \param output The SHA-224 or SHA-256 checksum result. 169 * This must be a writable buffer of length \c 32 bytes 170 * for SHA-256, \c 28 bytes for SHA-224. 171 * \param is224 Determines which function to use. This must be 172 * either \c 0 for SHA-256, or \c 1 for SHA-224. 173 * 174 * \return \c 0 on success. 175 * \return A negative error code on failure. 176 */ 177 int mbedtls_sha256(const unsigned char *input, 178 size_t ilen, 179 unsigned char *output, 180 int is224); 181 182 #if defined(MBEDTLS_SELF_TEST) 183 184 #if defined(MBEDTLS_SHA224_C) 185 /** 186 * \brief The SHA-224 checkup routine. 187 * 188 * \return \c 0 on success. 189 * \return \c 1 on failure. 190 */ 191 int mbedtls_sha224_self_test(int verbose); 192 #endif /* MBEDTLS_SHA224_C */ 193 194 #if defined(MBEDTLS_SHA256_C) 195 /** 196 * \brief The SHA-256 checkup routine. 197 * 198 * \return \c 0 on success. 199 * \return \c 1 on failure. 200 */ 201 int mbedtls_sha256_self_test(int verbose); 202 #endif /* MBEDTLS_SHA256_C */ 203 204 #endif /* MBEDTLS_SELF_TEST */ 205 206 #ifdef __cplusplus 207 } 208 #endif 209 210 #endif /* mbedtls_sha256.h */ 211