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 (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved 11 * Copyright (C) 2018-2022, Intel Corporation. 12 * SPDX-License-Identifier: Apache-2.0 13 * 14 * Licensed under the Apache License, Version 2.0 (the "License"); you may 15 * not use this file except in compliance with the License. 16 * You may obtain a copy of the License at 17 * 18 * http://www.apache.org/licenses/LICENSE-2.0 19 * 20 * Unless required by applicable law or agreed to in writing, software 21 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 22 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 23 * See the License for the specific language governing permissions and 24 * limitations under the License. 25 * 26 * This file is part of Mbed TLS (https://tls.mbed.org) 27 */ 28 #ifndef MBEDTLS_SHA256_H 29 #define MBEDTLS_SHA256_H 30 31 #include <types.h> 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_ret(). 39 */ 40 typedef struct 41 { 42 uint32_t total[2]; /*!< The number of Bytes processed. */ 43 uint32_t state[8]; /*!< The intermediate digest state. */ 44 uint8_t buffer[64]; /*!< The data block being processed. */ 45 int32_t is224; /*!< Determines which function to use: 46 0: Use SHA-256, or 1: Use SHA-224. */ 47 } 48 mbedtls_sha256_context; 49 50 /** 51 * \brief This function initializes a SHA-256 context. 52 * 53 * \param ctx The SHA-256 context to initialize. 54 */ 55 void mbedtls_sha256_init( mbedtls_sha256_context *ctx ); 56 57 /** 58 * \brief This function clears a SHA-256 context. 59 * 60 * \param ctx The SHA-256 context to clear. 61 */ 62 void mbedtls_sha256_free( mbedtls_sha256_context *ctx ); 63 64 /** 65 * \brief This function clones the state of a SHA-256 context. 66 * 67 * \param dst The destination context. 68 * \param src The context to clone. 69 */ 70 void mbedtls_sha256_clone( mbedtls_sha256_context *dst, 71 const mbedtls_sha256_context *src ); 72 73 /** 74 * \brief This function starts a SHA-224 or SHA-256 checksum 75 * calculation. 76 * 77 * \param ctx The context to initialize. 78 * \param is224 Determines which function to use: 79 * 0: Use SHA-256, or 1: Use SHA-224. 80 * 81 * \return \c 0 on success. 82 */ 83 int32_t mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int32_t is224 ); 84 85 /** 86 * \brief This function feeds an input buffer into an ongoing 87 * SHA-256 checksum calculation. 88 * 89 * \param ctx The SHA-256 context. 90 * \param input The buffer holding the data. 91 * \param ilen The length of the input data. 92 * 93 * \return \c 0 on success. 94 */ 95 int32_t mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx, 96 const uint8_t *input, 97 size_t ilen ); 98 99 /** 100 * \brief This function finishes the SHA-256 operation, and writes 101 * the result to the output buffer. 102 * 103 * \param ctx The SHA-256 context. 104 * \param output The SHA-224 or SHA-256 checksum result. 105 * 106 * \return \c 0 on success. 107 */ 108 int32_t mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx, 109 uint8_t output[32] ); 110 111 /** 112 * \brief This function processes a single data block within 113 * the ongoing SHA-256 computation. This function is for 114 * internal use only. 115 * 116 * \param ctx The SHA-256 context. 117 * \param data The buffer holding one block of data. 118 * 119 * \return \c 0 on success. 120 */ 121 int32_t mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx, 122 const uint8_t data[64] ); 123 124 /** 125 * \brief This function calculates the SHA-224 or SHA-256 126 * checksum of a buffer. 127 * 128 * The function allocates the context, performs the 129 * calculation, and frees the context. 130 * 131 * The SHA-256 result is calculated as 132 * output = SHA-256(input buffer). 133 * 134 * \param input The buffer holding the input data. 135 * \param ilen The length of the input data. 136 * \param output The SHA-224 or SHA-256 checksum result. 137 * \param is224 Determines which function to use: 138 * 0: Use SHA-256, or 1: Use SHA-224. 139 */ 140 int32_t mbedtls_sha256_ret( const uint8_t *input, 141 size_t ilen, 142 uint8_t output[32], 143 int32_t is224 ); 144 145 #endif /* mbedtls_sha256.h */ 146