/* * Copyright (c) 2016, The OpenThread Authors. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holder nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /** * @file * This file includes definitions for performing AES-CCM computations. */ #ifndef AES_CCM_HPP_ #define AES_CCM_HPP_ #include "openthread-core-config.h" #include #include #include "common/error.hpp" #include "common/message.hpp" #include "common/type_traits.hpp" #include "crypto/aes_ecb.hpp" #include "crypto/storage.hpp" #include "mac/mac_types.hpp" namespace ot { namespace Crypto { /** * @addtogroup core-security * * @{ * */ /** * Implements AES CCM computation. * */ class AesCcm { public: static constexpr uint8_t kMinTagLength = 4; ///< Minimum tag length (in bytes). static constexpr uint8_t kMaxTagLength = AesEcb::kBlockSize; ///< Maximum tag length (in bytes). static constexpr uint8_t kNonceSize = 13; ///< Size of IEEE 802.15.4 Nonce (in bytes). /** * Type represent the encryption vs decryption mode. * */ enum Mode : uint8_t { kEncrypt, // Encryption mode. kDecrypt, // Decryption mode. }; /** * Sets the key. * * @param[in] aKey Crypto Key used in AES operation * */ void SetKey(const Key &aKey) { mEcb.SetKey(aKey); } /** * Sets the key. * * @param[in] aKey A pointer to the key. * @param[in] aKeyLength Length of the key in bytes. * */ void SetKey(const uint8_t *aKey, uint16_t aKeyLength); /** * Sets the key. * * @param[in] aMacKey Key Material for AES operation. * */ void SetKey(const Mac::KeyMaterial &aMacKey); /** * Initializes the AES CCM computation. * * @param[in] aHeaderLength Length of header in bytes. * @param[in] aPlainTextLength Length of plaintext in bytes. * @param[in] aTagLength Length of tag in bytes (must be even and in `[kMinTagLength, kMaxTagLength]`). * @param[in] aNonce A pointer to the nonce. * @param[in] aNonceLength Length of nonce in bytes. * */ void Init(uint32_t aHeaderLength, uint32_t aPlainTextLength, uint8_t aTagLength, const void *aNonce, uint8_t aNonceLength); /** * Processes the header. * * @param[in] aHeader A pointer to the header. * @param[in] aHeaderLength Length of header in bytes. * */ void Header(const void *aHeader, uint32_t aHeaderLength); /** * Processes the header. * * @tparam ObjectType The object type. * * @param[in] aObject A reference to the object to add to header. * */ template void Header(const ObjectType &aObject) { static_assert(!TypeTraits::IsPointer::kValue, "ObjectType must not be a pointer"); Header(&aObject, sizeof(ObjectType)); } /** * Processes the payload. * * @param[in,out] aPlainText A pointer to the plaintext. * @param[in,out] aCipherText A pointer to the ciphertext. * @param[in] aLength Payload length in bytes. * @param[in] aMode Mode to indicate whether to encrypt (`kEncrypt`) or decrypt (`kDecrypt`). * */ void Payload(void *aPlainText, void *aCipherText, uint32_t aLength, Mode aMode); #if !OPENTHREAD_RADIO /** * Processes the payload within a given message. * * Encrypts/decrypts the payload content in place within the @p aMessage. * * @param[in,out] aMessage The message to read from and update. * @param[in] aOffset The offset in @p aMessage to start of payload. * @param[in] aLength Payload length in bytes. * @param[in] aMode Mode to indicate whether to encrypt (`kEncrypt`) or decrypt (`kDecrypt`). * */ void Payload(Message &aMessage, uint16_t aOffset, uint16_t aLength, Mode aMode); #endif /** * Returns the tag length in bytes. * * @returns The tag length in bytes. * */ uint8_t GetTagLength(void) const { return mTagLength; } /** * Generates the tag. * * @param[out] aTag A pointer to the tag (must have `GetTagLength()` bytes). * */ void Finalize(void *aTag); /** * Generates IEEE 802.15.4 nonce byte sequence. * * @param[in] aAddress An extended address. * @param[in] aFrameCounter A frame counter. * @param[in] aSecurityLevel A security level. * @param[out] aNonce A buffer (with `kNonceSize` bytes) to place the generated nonce. * */ static void GenerateNonce(const Mac::ExtAddress &aAddress, uint32_t aFrameCounter, uint8_t aSecurityLevel, uint8_t *aNonce); private: AesEcb mEcb; uint8_t mBlock[AesEcb::kBlockSize]; uint8_t mCtr[AesEcb::kBlockSize]; uint8_t mCtrPad[AesEcb::kBlockSize]; uint32_t mHeaderLength; uint32_t mHeaderCur; uint32_t mPlainTextLength; uint32_t mPlainTextCur; uint16_t mBlockLength; uint16_t mCtrLength; uint8_t mNonceLength; uint8_t mTagLength; }; /** * @} * */ } // namespace Crypto } // namespace ot #endif // AES_CCM_HPP_