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 +1,147 @@
+	/**
+	 * @file EcbModeImpl.h
+	 * @brief Declaration of tc::crypto::detail::EcbModeImpl
+	 * @author Jack (jakcron)
+	 * @version 0.1
+	 * @date 2020/07/04
+	 **/
+#pragma once
+#include <tc/types.h>
+
+#include <tc/ArgumentOutOfRangeException.h>
+#include <tc/ArgumentNullException.h>
+
+namespace tc { namespace crypto { namespace detail {
+
+	/**
+	 * @class EcbModeImpl
+	 * @brief This class implements the ECB (<b>e</b>lectronic <b>c</b>ode<b>b</b>ook) mode cipher as a template class.
+	 * 
+	 * @tparam BlockCipher The class that implements the block cipher used for ECB 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 EcbModeImpl
+{
+public:
+	static const size_t kKeySize = BlockCipher::kKeySize;
+	static const size_t kBlockSize = BlockCipher::kBlockSize;
+
+	EcbModeImpl() :
+		mState(None),
+		mCipher()
+	{
+
+	}
+
+	void initialize(const byte_t* key, size_t key_size) 
+	{
+		if (key == nullptr) { throw tc::ArgumentNullException("EcbModeImpl::initialize()", "key was null."); }
+		if (key_size != kKeySize) { throw tc::ArgumentOutOfRangeException("EcbModeImpl::initialize()", "key_size did not equal kKeySize."); }
+
+		mCipher.initialize(key, key_size);
+		mState = State::Initialized;
+	}
+
+	void encrypt(byte_t* dst, const byte_t* src, size_t size)
+	{
+		if (mState != State::Initialized) { return ; }
+		if (dst == nullptr) { throw tc::ArgumentNullException("EcbModeImpl::encrypt()", "dst was null."); }
+		if (src == nullptr) { throw tc::ArgumentNullException("EcbModeImpl::encrypt()", "src was null."); }
+		if (size < kBlockSize) { throw tc::ArgumentOutOfRangeException("EcbModeImpl::encrypt()", "size was less than kBlockSize."); }
+
+		// for ciphertext stealing
+		size_t block_leftover = size % kBlockSize;
+
+		// iterate through blocks
+		for (size_t block_idx = 0, block_num = (size / kBlockSize); block_idx < block_num; block_idx++)
+		{
+			mCipher.encrypt(dst + (block_idx * kBlockSize), src + (block_idx * kBlockSize));
+		}
+		
+		// cipher text stealing
+		if (block_leftover)
+		{
+			size_t block_idx = (size / kBlockSize);
+			const byte_t* src_block = src + (block_idx * kBlockSize);
+			byte_t* prev_dst_block = dst + ((block_idx - 1) * kBlockSize);
+			byte_t* dst_block = dst + (block_idx * kBlockSize);
+
+			// part 1 : prep encryption thru cipher text stealing
+			std::array<byte_t, kBlockSize> block;
+
+			// block [0, block_leftover) = src_block [0, block_leftover)
+			memcpy(block.data(), src_block, block_leftover);
+
+			// block [block_leftover-kBlockSize with previous) = prev_dst_block [block_leftover-kBlockSize)
+			memcpy(block.data() + block_leftover, prev_dst_block + block_leftover, kBlockSize - block_leftover);
+
+			// dst_block [0-block_leftover) = prev_dst_block [0-block_leftover)
+			memcpy(dst_block, prev_dst_block, block_leftover);
+
+			// part 2 : encrypt block
+			mCipher.encrypt(prev_dst_block, block.data());
+		}
+	}
+
+	void decrypt(byte_t* dst, const byte_t* src, size_t size)
+	{
+		if (mState != State::Initialized) { return ; }
+		if (dst == nullptr) { throw tc::ArgumentNullException("EcbModeImpl::decrypt()", "dst was null."); }
+		if (src == nullptr) { throw tc::ArgumentNullException("EcbModeImpl::decrypt()", "src was null."); }
+		if (size < kBlockSize) { throw tc::ArgumentOutOfRangeException("EcbModeImpl::decrypt()", "size less than kBlockSize."); }
+
+		// for ciphertext stealing
+		size_t block_leftover = size % kBlockSize;
+
+		// iterate through blocks
+		for (size_t block_idx = 0, block_num = (size / kBlockSize); block_idx < block_num; block_idx++)
+		{
+			mCipher.decrypt(dst + (block_idx * kBlockSize), src + (block_idx * kBlockSize));
+		}
+
+		// cipher text stealing
+		if (block_leftover)
+		{
+			size_t block_idx = (size / kBlockSize);
+			const byte_t* src_block = src + (block_idx * kBlockSize);
+			byte_t* prev_dst_block = dst + ((block_idx - 1) * kBlockSize);
+			byte_t* dst_block = dst + (block_idx * kBlockSize);
+
+			// part 1 : prep encryption thru cipher text stealing
+			std::array<byte_t, kBlockSize> block;
+
+			// block [0, block_leftover) = src_block [0, block_leftover)
+			memcpy(block.data(), src_block, block_leftover);
+
+			// block [block_leftover-kBlockSize with previous) = prev_dst_block [block_leftover-kBlockSize)
+			memcpy(block.data() + block_leftover, prev_dst_block + block_leftover, kBlockSize - block_leftover);
+
+			// dst_block [0-block_leftover) = prev_dst_block [0-block_leftover)
+			memcpy(dst_block, prev_dst_block, block_leftover);
+
+			// part 2 : encrypt block
+			mCipher.decrypt(prev_dst_block, block.data());
+		}
+	}
+private:
+	enum State
+	{
+		None,
+		Initialized
+	};
+
+	State mState;
+	
+	BlockCipher mCipher;
+};
+
+}}} // namespace tc::crypto::detail