79 lines
2.1 KiB
C
79 lines
2.1 KiB
C
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#pragma once
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#include <bitset>
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#include <sstream>
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#include "Block.h"
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//! Mod-operator that works with negative values
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inline int Mod(int numerator, int denominator)
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{
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return (denominator + (numerator % denominator)) % denominator;
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}
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//! Will perform a wrapping left-bitshift on a bitset
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template <std::size_t T>
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inline std::bitset<T> Shiftl(const std::bitset<T>& bits, std::size_t amount)
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{
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std::stringstream ss;
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const std::string bitss = bits.to_string();
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for (std::size_t i = 0; i < bitss.size(); i++)
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ss << bitss[Mod((i + amount), bitss.size())];
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return std::bitset<T>(ss.str());
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}
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//! Will perform a wrapping right-bitshift on a bitset
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template <std::size_t T>
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inline std::bitset<T> Shiftr(const std::bitset<T>& bits, std::size_t amount)
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{
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std::stringstream ss;
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const std::string bitss = bits.to_string();
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for (std::size_t i = 0; i < bitss.size(); i++)
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ss << bitss[Mod((i - amount), bitss.size())];
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return std::bitset<T>(ss.str());
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}
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//! Will convert a string to a data block
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inline Block StringToBits(const std::string& s)
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{
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std::stringstream ss;
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for (std::size_t i = 0; i < s.size(); i++)
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ss << std::bitset<8>(s[i]);
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// Pad rest with zeores
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for (std::size_t i = s.size() * 8; i < BLOCK_SIZE; i++)
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ss << '0';
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return Block(ss.str());
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}
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//! Will convert a data block to a string
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inline std::string BitsToString(const Block& bits)
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{
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std::stringstream ss;
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const std::string bitstring = bits.to_string();
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for (std::size_t i = 0; i < BLOCK_SIZE; i += 8)
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{
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ss << (char)std::bitset<8>(bitstring.substr(i, 8)).to_ulong();
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}
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return ss.str();
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}
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//! Creates a key of size key-size from a password of arbitrary length.
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inline Block PasswordToKey(const std::string& in)
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{
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Block b;
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// Segment the password in segments of key-size, and xor them together.
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for (std::size_t i = 0; i < in.size(); i += BLOCK_SIZE / 8)
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b ^= StringToBits(in.substr(i, BLOCK_SIZE / 8));
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return b;
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}
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