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