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 { 54 uint32_t MBEDTLS_PRIVATE(total)[2]; /*!< The number of Bytes processed. */ 55 uint32_t MBEDTLS_PRIVATE(state)[8]; /*!< The intermediate digest state. */ 56 unsigned char MBEDTLS_PRIVATE(buffer)[64]; /*!< The data block being processed. */ 57 int MBEDTLS_PRIVATE(is224); /*!< Determines which function to use: 58 0: Use SHA-256, or 1: Use SHA-224. */ 59 } 60 mbedtls_sha256_context; 61 62 #else /* MBEDTLS_SHA256_ALT */ 63 #include "sha256_alt.h" 64 #endif /* MBEDTLS_SHA256_ALT */ 65 66 /** 67 * \brief This function initializes a SHA-256 context. 68 * 69 * \param ctx The SHA-256 context to initialize. This must not be \c NULL. 70 */ 71 void mbedtls_sha256_init( mbedtls_sha256_context *ctx ); 72 73 /** 74 * \brief This function clears a SHA-256 context. 75 * 76 * \param ctx The SHA-256 context to clear. This may be \c NULL, in which 77 * case this function returns immediately. If it is not \c NULL, 78 * it must point to an initialized SHA-256 context. 79 */ 80 void mbedtls_sha256_free( mbedtls_sha256_context *ctx ); 81 82 /** 83 * \brief This function clones the state of a SHA-256 context. 84 * 85 * \param dst The destination context. This must be initialized. 86 * \param src The context to clone. This must be initialized. 87 */ 88 void mbedtls_sha256_clone( mbedtls_sha256_context *dst, 89 const mbedtls_sha256_context *src ); 90 91 /** 92 * \brief This function starts a SHA-224 or SHA-256 checksum 93 * calculation. 94 * 95 * \param ctx The context to use. This must be initialized. 96 * \param is224 This determines which function to use. This must be 97 * either \c 0 for SHA-256, or \c 1 for SHA-224. 98 * 99 * \return \c 0 on success. 100 * \return A negative error code on failure. 101 */ 102 int mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 ); 103 104 /** 105 * \brief This function feeds an input buffer into an ongoing 106 * SHA-256 checksum calculation. 107 * 108 * \param ctx The SHA-256 context. This must be initialized 109 * and have a hash operation started. 110 * \param input The buffer holding the data. This must be a readable 111 * buffer of length \p ilen Bytes. 112 * \param ilen The length of the input data in Bytes. 113 * 114 * \return \c 0 on success. 115 * \return A negative error code on failure. 116 */ 117 int mbedtls_sha256_update( mbedtls_sha256_context *ctx, 118 const unsigned char *input, 119 size_t ilen ); 120 121 /** 122 * \brief This function finishes the SHA-256 operation, and writes 123 * the result to the output buffer. 124 * 125 * \param ctx The SHA-256 context. This must be initialized 126 * and have a hash operation started. 127 * \param output The SHA-224 or SHA-256 checksum result. 128 * This must be a writable buffer of length \c 32 bytes 129 * for SHA-256, \c 28 bytes for SHA-224. 130 * 131 * \return \c 0 on success. 132 * \return A negative error code on failure. 133 */ 134 int mbedtls_sha256_finish( mbedtls_sha256_context *ctx, 135 unsigned char *output ); 136 137 /** 138 * \brief This function processes a single data block within 139 * the ongoing SHA-256 computation. This function is for 140 * internal use only. 141 * 142 * \param ctx The SHA-256 context. This must be initialized. 143 * \param data The buffer holding one block of data. This must 144 * be a readable buffer of length \c 64 Bytes. 145 * 146 * \return \c 0 on success. 147 * \return A negative error code on failure. 148 */ 149 int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx, 150 const unsigned char data[64] ); 151 152 /** 153 * \brief This function calculates the SHA-224 or SHA-256 154 * checksum of a buffer. 155 * 156 * The function allocates the context, performs the 157 * calculation, and frees the context. 158 * 159 * The SHA-256 result is calculated as 160 * output = SHA-256(input buffer). 161 * 162 * \param input The buffer holding the data. This must be a readable 163 * buffer of length \p ilen Bytes. 164 * \param ilen The length of the input data in Bytes. 165 * \param output The SHA-224 or SHA-256 checksum result. 166 * This must be a writable buffer of length \c 32 bytes 167 * for SHA-256, \c 28 bytes for SHA-224. 168 * \param is224 Determines which function to use. This must be 169 * either \c 0 for SHA-256, or \c 1 for SHA-224. 170 */ 171 int mbedtls_sha256( const unsigned char *input, 172 size_t ilen, 173 unsigned char *output, 174 int is224 ); 175 176 #if defined(MBEDTLS_SELF_TEST) 177 178 /** 179 * \brief The SHA-224 and SHA-256 checkup routine. 180 * 181 * \return \c 0 on success. 182 * \return \c 1 on failure. 183 */ 184 int mbedtls_sha256_self_test( int verbose ); 185 186 #endif /* MBEDTLS_SELF_TEST */ 187 188 #ifdef __cplusplus 189 } 190 #endif 191 192 #endif /* mbedtls_sha256.h */ 193