2022-05-16 21:43:22 +02:00

320 lines
9.7 KiB
C++

#pragma once
#include <bitset>
#include <sstream>
#include <fstream>
#include <cstring>
#include "SecureBitset.h"
#include "Block.h"
#include "Flexblock.h"
#include "Config.h"
#include "Cipher.h"
#include "InitializationVector.h"
namespace GhettoCipher
{
//! Mod-operator that works with negative values
inline int Mod(const int numerator, const int denominator)
{
return (denominator + (numerator % denominator)) % denominator;
}
//! Will perform a wrapping left-bitshift on a bitset
template <std::size_t T>
inline SecureBitset<T> Shiftl(const SecureBitset<T>& bits, const std::size_t amount)
{
std::stringstream ss;
const std::string bitss = bits.to_string();
for (std::size_t i = 0; i < bitss.size(); i++)
ss << bitss[Mod((int)(i + amount), (int)bitss.size())];
return SecureBitset<T>(ss.str());
}
//! Will perform a wrapping right-bitshift on a bitset
template <std::size_t T>
inline SecureBitset<T> Shiftr(const SecureBitset<T>& bits, const std::size_t amount)
{
std::stringstream ss;
const std::string bitss = bits.to_string();
for (std::size_t i = 0; i < bitss.size(); i++)
ss << bitss[Mod((i - amount), bitss.size())];
return SecureBitset<T>(ss.str());
}
//! Will pad a string to a set length with a certain character
inline std::string PadStringToLength(const std::string& str, const std::size_t len, const char pad, const bool padLeft = true)
{
// Fast-reject: Already above padded length
if (str.length() >= len)
return str;
std::stringstream ss;
// Pad left:
if (padLeft)
{
for (std::size_t i = 0; i < len - str.size(); i++)
ss << pad;
ss << str;
}
// Pad right:
else
{
ss << str;
for (std::size_t i = 0; i < len - str.size(); i++)
ss << pad;
}
return ss.str();
}
//! Will convert a string to a fixed-size data block
inline Block StringToBitblock(const std::string& s)
{
std::stringstream ss;
for (std::size_t i = 0; i < s.size(); i++)
ss << std::bitset<8>(s[i]);
// Pad rest with zeores
return Block(PadStringToLength(ss.str(), 128, '0', false));
}
//! Will convert a string to a flexible data block
inline Flexblock StringToBits(const std::string& s)
{
std::stringstream ss;
for (std::size_t i = 0; i < s.size(); i++)
ss << std::bitset<8>(s[i]);
return Flexblock(ss.str());
}
//! Will convert a fixed-size data block to a bytestring
inline std::string BitblockToBytes(const Block& bits)
{
std::stringstream ss;
const std::string bitstring = bits.to_string();
for (std::size_t i = 0; i < BLOCK_SIZE; i += 8)
{
ss << (char)std::bitset<8>(bitstring.substr(i, 8)).to_ulong();
}
return ss.str();
}
//! Will convert a fixed-size data block to a string
//! The difference to BitblockToBytes() is, that it strips excess nullbytes
inline std::string BitblockToString(const Block& bits)
{
// Decode to bytes
std::string text = BitblockToBytes(bits);
// Dümp excess nullbytes
text.resize(strlen(text.data()));
return text;
}
//! Will convert a flexible data block to a bytestring
inline std::string BitsToBytes(const Flexblock& bits)
{
std::stringstream ss;
const std::string bitstring = bits;
for (std::size_t i = 0; i < bits.size(); i += 8)
{
ss << (char)std::bitset<8>(bitstring.substr(i, 8)).to_ulong();
}
return ss.str();
}
//! Will convert a flexible data block to a string
//! //! The difference to BitsToBytes() is, that it strips excess nullbytes
inline std::string BitsToString(const Flexblock& bits)
{
// Decode to bytes
std::string text = BitsToBytes(bits);
// Dümp excess nullbytes
text.resize(strlen(text.data()));
return text;
}
//! Turns a fixed-size data block into a hex-string
inline std::string BitblockToHexstring(const Block& b)
{
std::stringstream ss;
const std::string charset = "0123456789abcdef";
const std::string bstr = b.to_string();
for (std::size_t i = 0; i < bstr.size(); i += 4)
ss << charset[std::bitset<4>(bstr.substr(i, 4)).to_ulong()];
return ss.str();
}
//! Turns a flexible data block into a hex-string
inline std::string BitsToHexstring(const Flexblock& b)
{
std::stringstream ss;
const std::string charset = "0123456789abcdef";
const std::string bstr = b;
for (std::size_t i = 0; i < bstr.size(); i += 4)
ss << charset[std::bitset<4>(bstr.substr(i, 4)).to_ulong()];
return ss.str();
}
//! Turns a hex string into a fixed-size data block
inline Block HexstringToBitblock(const std::string& hexstring)
{
std::stringstream ss;
for (std::size_t i = 0; i < hexstring.size(); i++)
{
const char c = hexstring[i];
// Get value
std::size_t value;
if ((c >= '0') && (c <= '9'))
// Is it a number?
value = ((std::size_t)c - '0') + 0;
else if ((c >= 'a') && (c <= 'f'))
// Else, it is a lowercase letter
value = ((std::size_t)c - 'a') + 10;
else
throw std::logic_error("non-hex string detected in HexstringToBits()");
// Append to our bits
ss << std::bitset<4>(value);
}
return Block(ss.str());
}
//! Turns a hex string into a flexible data block
inline Flexblock HexstringToBits(const std::string& hexstring)
{
std::stringstream ss;
for (std::size_t i = 0; i < hexstring.size(); i++)
{
const char c = hexstring[i];
// Get value
std::size_t value;
if ((c >= '0') && (c <= '9'))
// Is it a number?
value = ((std::size_t)c - '0') + 0;
else if ((c >= 'a') && (c <= 'f'))
// Else, it is a lowercase letter
value = ((std::size_t)c - 'a') + 10;
else
throw std::logic_error("non-hex string detected in HexstringToBits()");
// Append to our bits
ss << std::bitset<4>(value);
}
return ss.str();
}
//! Creates a key of size BLOCK_SIZE from a password of arbitrary length.
//! Note that if your password is shorter (in bits) than BLOCK_SIZE, the rest of the key will be padded with 0 (see next line!).
//! To provide a better initial key, (and to get rid of padding zeroes), the raw result (b) will be xor'd with an initialization vector based on b.
//! : return b ^ iv(b)
inline Block PasswordToKey(const std::string& in)
{
// Let's provide a nice initial value to be sure even a password of length 0 results in a proper key
Block b = InitializationVector(StringToBitblock("3J7IipfQTDJbO8jtasz9PgWui6faPaEMOuVuAqyhB1S2CRcLw5caawewgDUEG1WN"));
// Segment the password in segments of key-size, and xor them together.
for (std::size_t i = 0; i < in.size(); i += BLOCK_SIZE / 8)
{
const Block fragment = StringToBitblock(
PadStringToLength(in.substr(i, BLOCK_SIZE / 8), BLOCK_SIZE / 8, 0, false)
);
// To provide confusion, xor the blocks together
// To provide diffusion, hash fragment to fragment' first
b ^= Block(Cipher(fragment).Encipher(fragment.to_string()));
}
return b;
}
//! Will reduce a flexblock (they are of arbitrary length) to a single block.
//! This single block should change completely, if a single bit in the input flexblock changes anywhere.
inline Block ReductionFunction_Flexblock2Block(const Flexblock& in)
{
Block b; // No initialization vector needed here
// Segment the input in segments of BLOCK_SIZE, and xor them together.
for (std::size_t i = 0; i < in.size(); i += BLOCK_SIZE)
{
const Block fragment = Block(PadStringToLength(in.substr(i, BLOCK_SIZE), BLOCK_SIZE, 0, false));
// To provide confusion, xor the blocks together
// To provide diffusion, hash fragment to fragment' first
b ^= Block(Cipher(fragment).Encipher(fragment.to_string()));
}
return b;
}
//! Will read a file into a flexblock
inline Flexblock ReadFileToBits(const std::string& filepath)
{
// Read file
std::ifstream ifs(filepath, std::ios::binary);
if (!ifs.good())
throw std::runtime_error("Unable to open ifilestream!");
std::stringstream ss;
std::copy(
std::istreambuf_iterator<char>(ifs),
std::istreambuf_iterator<char>(),
std::ostreambuf_iterator<char>(ss)
);
ifs.close();
const std::string bytes = ss.str();
// Convert bytes to bits
return StringToBits(bytes);
}
//! Will save bits to a binary file
inline void WriteBitsToFile(const std::string& filepath, const Flexblock& bits)
{
// Convert bits to bytes
const std::string bytes = BitsToBytes(bits);
// Write bits to file
std::ofstream ofs(filepath, std::ios::binary);
if (!ofs.good())
throw std::runtime_error("Unable to open ofilestream!");
ofs.write(bytes.data(), bytes.length());
ofs.close();
return;
}
}