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 HMAC SHA-256 computations. 32 */ 33 34 #ifndef HMAC_SHA256_HPP_ 35 #define HMAC_SHA256_HPP_ 36 37 #include "openthread-core-config.h" 38 39 #include <stdint.h> 40 41 #include <openthread/platform/crypto.h> 42 43 #include "common/code_utils.hpp" 44 #include "crypto/context_size.hpp" 45 #include "crypto/sha256.hpp" 46 #include "crypto/storage.hpp" 47 48 namespace ot { 49 50 class Message; 51 52 namespace Crypto { 53 54 /** 55 * @addtogroup core-security 56 * 57 * @{ 58 */ 59 60 /** 61 * Implements HMAC SHA-256 computation. 62 */ 63 class HmacSha256 64 { 65 public: 66 /** 67 * Represents a HMAC SHA-256 hash. 68 */ 69 typedef Sha256::Hash Hash; 70 71 /** 72 * Constructor for `HmacSha256`. 73 */ 74 HmacSha256(void); 75 76 /** 77 * Destructor for `HmacSha256`. 78 */ 79 ~HmacSha256(void); 80 81 /** 82 * Sets the key and starts the HMAC computation. 83 * 84 * @param[in] aKey The key to use. 85 */ 86 void Start(const Key &aKey); 87 88 /** 89 * Inputs bytes into the HMAC computation. 90 * 91 * @param[in] aBuf A pointer to the input buffer. 92 * @param[in] aBufLength The length of @p aBuf in bytes. 93 */ 94 void Update(const void *aBuf, uint16_t aBufLength); 95 96 /** 97 * Inputs an object (treated as a sequence of bytes) into the HMAC computation. 98 * 99 * @tparam ObjectType The object type. 100 * 101 * @param[in] aObject A reference to the object. 102 */ Update(const ObjectType & aObject)103 template <typename ObjectType> void Update(const ObjectType &aObject) 104 { 105 static_assert(!TypeTraits::IsPointer<ObjectType>::kValue, "ObjectType must not be a pointer"); 106 return Update(&aObject, sizeof(ObjectType)); 107 } 108 109 /** 110 * Inputs the bytes read from a given message into the HMAC computation. 111 * 112 * @param[in] aMessage The message to read the data from. 113 * @param[in] aOffset The offset into @p aMessage to start to read. 114 * @param[in] aLength The number of bytes to read. 115 */ 116 void Update(const Message &aMessage, uint16_t aOffset, uint16_t aLength); 117 118 /** 119 * Finalizes the hash computation. 120 * 121 * @param[out] aHash A reference to a `Hash` to output the calculated hash. 122 */ 123 void Finish(Hash &aHash); 124 125 private: 126 otCryptoContext mContext; 127 OT_DEFINE_ALIGNED_VAR(mContextStorage, kHmacSha256ContextSize, uint64_t); 128 }; 129 130 /** 131 * @} 132 */ 133 134 } // namespace Crypto 135 } // namespace ot 136 137 #endif // HMAC_SHA256_HPP_ 138