55 lines
1.4 KiB
C++
55 lines
1.4 KiB
C++
#include <iostream>
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#include <vector>
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#include <stdexcept>
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#include "GCrypt/GCipher.h"
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#include "GCrypt/Util.h"
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#include "GCrypt/InitializationVector.h"
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namespace Leonetienne::GCrypt {
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GCipher::GCipher(const Key& key, const DIRECTION direction)
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:
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direction { direction },
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lastBlock(InitializationVector(key)), // Initialize our lastBlock with some deterministic initial value, based on the key
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feistel(key) {
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return;
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}
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Block GCipher::Digest(const Block& input) {
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switch (direction) {
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case DIRECTION::ENCIPHER: {
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// Rename our input to cleartext
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const Block& cleartext = input;
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// First, xor our cleartext with the last block, and then encipher it
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Block ciphertext = feistel.Encipher(cleartext ^ lastBlock);
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// Now set our lastBlock to the ciphertext of this block
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lastBlock = ciphertext;
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// Now return the ciphertext
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return ciphertext;
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}
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case DIRECTION::DECIPHER: {
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// Rename our input into ciphertext
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const Block& ciphertext = input;
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// First, decipher our ciphertext, and then xor it with our last block
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Block cleartext = feistel.Decipher(ciphertext) ^ lastBlock;
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// Now set our lastBLock to the ciphertext of this block
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lastBlock = ciphertext;
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// Now return the cleartext
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return cleartext;
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}
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}
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throw std::runtime_error("Unreachable branch reached.");
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}
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}
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