1 /* 2 * Copyright (c) 2016, The OpenThread Authors. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Neither the name of the copyright holder nor the 13 * names of its contributors may be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /** 30 * @file 31 * This file includes definitions for performing SHA-256 computations. 32 */ 33 34 #ifndef SHA256_HPP_ 35 #define SHA256_HPP_ 36 37 #include "openthread-core-config.h" 38 39 #include <stdint.h> 40 41 #include <openthread/crypto.h> 42 #include <openthread/platform/crypto.h> 43 44 #include "common/as_core_type.hpp" 45 #include "common/clearable.hpp" 46 #include "common/code_utils.hpp" 47 #include "common/equatable.hpp" 48 #include "common/type_traits.hpp" 49 #include "crypto/context_size.hpp" 50 51 namespace ot { 52 53 class Message; 54 55 namespace Crypto { 56 57 /** 58 * @addtogroup core-security 59 * 60 * @{ 61 */ 62 63 /** 64 * Implements SHA-256 computation. 65 */ 66 class Sha256 67 { 68 public: 69 /** 70 * Represents a SHA-256 hash. 71 */ 72 class Hash : public otCryptoSha256Hash, public Clearable<Hash>, public Equatable<Hash> 73 { 74 public: 75 static const uint8_t kSize = OT_CRYPTO_SHA256_HASH_SIZE; ///< SHA-256 hash size (bytes) 76 77 /** 78 * Returns a pointer to a byte array containing the hash value. 79 * 80 * @returns A pointer to a byte array containing the hash. 81 */ GetBytes(void) const82 const uint8_t *GetBytes(void) const { return m8; } 83 }; 84 85 /** 86 * Constructor for `Sha256` object. 87 */ 88 Sha256(void); 89 90 /** 91 * Destructor for `Sha256` object. 92 */ 93 ~Sha256(void); 94 95 /** 96 * Starts the SHA-256 computation. 97 */ 98 void Start(void); 99 100 /** 101 * Inputs bytes into the SHA-256 computation. 102 * 103 * @param[in] aBuf A pointer to the input buffer. 104 * @param[in] aBufLength The length of @p aBuf in bytes. 105 */ 106 void Update(const void *aBuf, uint16_t aBufLength); 107 108 /** 109 * Inputs an object (treated as a sequence of bytes) into the SHA-256 computation. 110 * 111 * @tparam ObjectType The object type. 112 * 113 * @param[in] aObject A reference to the object. 114 */ Update(const ObjectType & aObject)115 template <typename ObjectType> void Update(const ObjectType &aObject) 116 { 117 static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer"); 118 return Update(&aObject, sizeof(ObjectType)); 119 } 120 121 /** 122 * Inputs the bytes read from a given message into the SHA-256 computation. 123 * 124 * @param[in] aMessage The message to read the data from. 125 * @param[in] aOffset The offset into @p aMessage to start to read. 126 * @param[in] aLength The number of bytes to read. 127 */ 128 void Update(const Message &aMessage, uint16_t aOffset, uint16_t aLength); 129 130 /** 131 * Finalizes the hash computation. 132 * 133 * @param[out] aHash A reference to a `Hash` to output the calculated hash. 134 */ 135 void Finish(Hash &aHash); 136 137 private: 138 otCryptoContext mContext; 139 OT_DEFINE_ALIGNED_VAR(mContextStorage, kSha256ContextSize, uint64_t); 140 }; 141 142 /** 143 * @} 144 */ 145 146 } // namespace Crypto 147 148 DefineCoreType(otCryptoSha256Hash, Crypto::Sha256::Hash); 149 150 } // namespace ot 151 152 #endif // SHA256_HPP_ 153