Move dependencies to the top level.

2026-07-06 16:59:03 +00:00 · 2022-04-16 18:27:14 +08:00
parent b67980d3d2
commit 5d62e839e7
844 changed files with 74 additions and 114431 deletions
@@ -0,0 +1,113 @@
+	/**
+	 * @file CtrModeImpl.h
+	 * @brief Declaration of tc::crypto::detail::CtrModeImpl
+	 * @author Jack (jakcron)
+	 * @version 0.2
+	 * @date 2020/10/04
+	 **/
+#pragma once
+#include <tc/types.h>
+
+#include <tc/crypto/detail/BlockUtilImpl.h>
+
+#include <tc/ArgumentOutOfRangeException.h>
+#include <tc/ArgumentNullException.h>
+
+namespace tc { namespace crypto { namespace detail {
+
+	/**
+	 * @class CtrModeImpl
+	 * @brief This class implements the CTR (<b>c</b>oun<b>t</b>e<b>r</b>) mode cipher as a template class.
+	 * 
+	 * @tparam BlockCipher The class that implements the block cipher used for CTR mode encryption/decryption.
+	 * 
+	 * @details
+	 * The implementation of <var>BlockCipher</var> must satisfies the following conditions.
+	 * 
+	 * -# Has a <tt>kBlockSize</tt> constant that defines the size of the block to process.
+	 * -# Has a <tt>kKeySize</tt> constant that defines the required key size to initialize the block cipher.
+	 * -# Has an <tt>initialize</tt> method that initializes the state of the block cipher.
+	 * -# Has an <tt>encrypt</tt> method that encrypts a block of input data.
+	 * -# Has a <tt>decrypt</tt> method that decrypts a block of input data.
+	 */
+template <class BlockCipher>
+class CtrModeImpl
+{
+public:
+	static const size_t kKeySize = BlockCipher::kKeySize;
+	static const size_t kBlockSize = BlockCipher::kBlockSize;
+
+	CtrModeImpl() :
+		mState(None),
+		mCipher()
+	{
+
+	}
+
+	void initialize(const byte_t* key, size_t key_size, const byte_t* iv, size_t iv_size) 
+	{
+		if (key == nullptr) { throw tc::ArgumentNullException("CtrModeImpl::initialize()", "key was null."); }
+		if (key_size != kKeySize) { throw tc::ArgumentOutOfRangeException("CtrModeImpl::initialize()", "key_size did not equal kKeySize."); }
+		if (iv == nullptr) { throw tc::ArgumentNullException("CtrModeImpl::initialize()", "iv was null."); }
+		if (iv_size != kBlockSize) { throw tc::ArgumentOutOfRangeException("CtrModeImpl::initialize()", "iv_size did not equal kBlockSize."); }
+
+		mCipher.initialize(key, key_size);
+		memcpy(mIv.data(), iv, mIv.size());
+		mState = State::Initialized;
+	}
+
+	void crypt(byte_t* dst, const byte_t* src, size_t size, uint64_t block_number)
+	{
+		if (mState != State::Initialized) { return ; }
+		if (dst == nullptr) { throw tc::ArgumentNullException("CtrModeImpl::crypt()", "dst was null."); }
+		if (src == nullptr) { throw tc::ArgumentNullException("CtrModeImpl::crypt()", "src was null."); }
+		if (size == 0) { throw tc::ArgumentOutOfRangeException("CtrModeImpl::crypt()", "size was 0."); }
+
+		auto iv = std::array<byte_t, kBlockSize>();
+		auto enc_iv = std::array<byte_t, kBlockSize>();
+
+		// import and increment iv
+		memcpy(iv.data(), mIv.data(), mIv.size());
+		incr_counter<kBlockSize>(iv.data(), block_number);
+
+		// iterate through blocks
+		for (size_t block_idx = 0, block_num = (size / kBlockSize); block_idx < block_num; block_idx++)
+		{
+			// encrypt IV
+			mCipher.encrypt(enc_iv.data(), iv.data());
+
+			// dst = src ^ enc_iv
+			xor_block<kBlockSize>(dst + (block_idx * kBlockSize), src + (block_idx * kBlockSize), enc_iv.data());
+
+			// increment counter
+			incr_counter<kBlockSize>(iv.data(), 1);
+		}
+
+		// process partial block
+		size_t block_remaining = (size % kBlockSize);
+		if (block_remaining > 0)
+		{
+			// encrypt IV
+			mCipher.encrypt(enc_iv.data(), iv.data());
+
+			// dst = src ^ enc_iv
+			for (size_t i = 0; i < block_remaining; i++)
+			{
+				dst[((size / kBlockSize) * kBlockSize) + i] = src[((size / kBlockSize) * kBlockSize) + i] ^ enc_iv[i];
+			}
+		}
+	}
+private:
+	enum State
+	{
+		None,
+		Initialized
+	};
+
+	State mState;
+	
+	BlockCipher mCipher;
+	std::array<byte_t, kBlockSize> mIv;
+};
+
+}}} // namespace tc::crypto::detail