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 OR GPL-2.0-or-later 12 */ 13 #ifndef MBEDTLS_SHA256_H 14 #define MBEDTLS_SHA256_H 15 #include "mbedtls/private_access.h" 16 17 #include "mbedtls/build_info.h" 18 19 #include <stddef.h> 20 #include <stdint.h> 21 22 /** SHA-256 input data was malformed. */ 23 #define MBEDTLS_ERR_SHA256_BAD_INPUT_DATA -0x0074 24 25 #ifdef __cplusplus 26 extern "C" { 27 #endif 28 29 #if !defined(MBEDTLS_SHA256_ALT) 30 // Regular implementation 31 // 32 33 /** 34 * \brief The SHA-256 context structure. 35 * 36 * The structure is used both for SHA-256 and for SHA-224 37 * checksum calculations. The choice between these two is 38 * made in the call to mbedtls_sha256_starts(). 39 */ 40 typedef struct mbedtls_sha256_context { 41 unsigned char MBEDTLS_PRIVATE(buffer)[64]; /*!< The data block being processed. */ 42 uint32_t MBEDTLS_PRIVATE(total)[2]; /*!< The number of Bytes processed. */ 43 uint32_t MBEDTLS_PRIVATE(state)[8]; /*!< The intermediate digest state. */ 44 #if defined(MBEDTLS_SHA224_C) 45 int MBEDTLS_PRIVATE(is224); /*!< Determines which function to use: 46 0: Use SHA-256, or 1: Use SHA-224. */ 47 #endif 48 } 49 mbedtls_sha256_context; 50 51 #else /* MBEDTLS_SHA256_ALT */ 52 #include "sha256_alt.h" 53 #endif /* MBEDTLS_SHA256_ALT */ 54 55 /** 56 * \brief This function initializes a SHA-256 context. 57 * 58 * \param ctx The SHA-256 context to initialize. This must not be \c NULL. 59 */ 60 void mbedtls_sha256_init(mbedtls_sha256_context *ctx); 61 62 /** 63 * \brief This function clears a SHA-256 context. 64 * 65 * \param ctx The SHA-256 context to clear. This may be \c NULL, in which 66 * case this function returns immediately. If it is not \c NULL, 67 * it must point to an initialized SHA-256 context. 68 */ 69 void mbedtls_sha256_free(mbedtls_sha256_context *ctx); 70 71 /** 72 * \brief This function clones the state of a SHA-256 context. 73 * 74 * \param dst The destination context. This must be initialized. 75 * \param src The context to clone. This must be initialized. 76 */ 77 void mbedtls_sha256_clone(mbedtls_sha256_context *dst, 78 const mbedtls_sha256_context *src); 79 80 /** 81 * \brief This function starts a SHA-224 or SHA-256 checksum 82 * calculation. 83 * 84 * \param ctx The context to use. This must be initialized. 85 * \param is224 This determines which function to use. This must be 86 * either \c 0 for SHA-256, or \c 1 for SHA-224. 87 * 88 * \note is224 must be defined accordingly to the enabled 89 * MBEDTLS_SHA224_C/MBEDTLS_SHA256_C symbols otherwise the 90 * function will return #MBEDTLS_ERR_SHA512_BAD_INPUT_DATA. 91 * 92 * \return \c 0 on success. 93 * \return A negative error code on failure. 94 */ 95 int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224); 96 97 /** 98 * \brief This function feeds an input buffer into an ongoing 99 * SHA-256 checksum calculation. 100 * 101 * \param ctx The SHA-256 context. This must be initialized 102 * and have a hash operation started. 103 * \param input The buffer holding the data. This must be a readable 104 * buffer of length \p ilen Bytes. 105 * \param ilen The length of the input data in Bytes. 106 * 107 * \return \c 0 on success. 108 * \return A negative error code on failure. 109 */ 110 int mbedtls_sha256_update(mbedtls_sha256_context *ctx, 111 const unsigned char *input, 112 size_t ilen); 113 114 /** 115 * \brief This function finishes the SHA-256 operation, and writes 116 * the result to the output buffer. 117 * 118 * \param ctx The SHA-256 context. This must be initialized 119 * and have a hash operation started. 120 * \param output The SHA-224 or SHA-256 checksum result. 121 * This must be a writable buffer of length \c 32 bytes 122 * for SHA-256, \c 28 bytes for SHA-224. 123 * 124 * \return \c 0 on success. 125 * \return A negative error code on failure. 126 */ 127 int mbedtls_sha256_finish(mbedtls_sha256_context *ctx, 128 unsigned char *output); 129 130 /** 131 * \brief This function processes a single data block within 132 * the ongoing SHA-256 computation. This function is for 133 * internal use only. 134 * 135 * \param ctx The SHA-256 context. This must be initialized. 136 * \param data The buffer holding one block of data. This must 137 * be a readable buffer of length \c 64 Bytes. 138 * 139 * \return \c 0 on success. 140 * \return A negative error code on failure. 141 */ 142 int mbedtls_internal_sha256_process(mbedtls_sha256_context *ctx, 143 const unsigned char data[64]); 144 145 /** 146 * \brief This function calculates the SHA-224 or SHA-256 147 * checksum of a buffer. 148 * 149 * The function allocates the context, performs the 150 * calculation, and frees the context. 151 * 152 * The SHA-256 result is calculated as 153 * output = SHA-256(input buffer). 154 * 155 * \param input The buffer holding the data. This must be a readable 156 * buffer of length \p ilen Bytes. 157 * \param ilen The length of the input data in Bytes. 158 * \param output The SHA-224 or SHA-256 checksum result. 159 * This must be a writable buffer of length \c 32 bytes 160 * for SHA-256, \c 28 bytes for SHA-224. 161 * \param is224 Determines which function to use. This must be 162 * either \c 0 for SHA-256, or \c 1 for SHA-224. 163 * 164 * \return \c 0 on success. 165 * \return A negative error code on failure. 166 */ 167 int mbedtls_sha256(const unsigned char *input, 168 size_t ilen, 169 unsigned char *output, 170 int is224); 171 172 #if defined(MBEDTLS_SELF_TEST) 173 174 #if defined(MBEDTLS_SHA224_C) 175 /** 176 * \brief The SHA-224 checkup routine. 177 * 178 * \return \c 0 on success. 179 * \return \c 1 on failure. 180 */ 181 int mbedtls_sha224_self_test(int verbose); 182 #endif /* MBEDTLS_SHA224_C */ 183 184 #if defined(MBEDTLS_SHA256_C) 185 /** 186 * \brief The SHA-256 checkup routine. 187 * 188 * \return \c 0 on success. 189 * \return \c 1 on failure. 190 */ 191 int mbedtls_sha256_self_test(int verbose); 192 #endif /* MBEDTLS_SHA256_C */ 193 194 #endif /* MBEDTLS_SELF_TEST */ 195 196 #ifdef __cplusplus 197 } 198 #endif 199 200 #endif /* mbedtls_sha256.h */ 201
