Built single-header

INCLUDE/GhettoCrypt.cpp

@@ -0,0 +1,453 @@
+/*
+* BSD 2-Clause License
+* 
+* Copyright (c) 2021, Leon Etienne
+* All rights reserved.
+* 
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+* 
+* 1. Redistributions of source code must retain the above copyright notice, this
+*    list of conditions and the following disclaimer.
+* 
+* 2. Redistributions in binary form must reproduce the above copyright notice,
+*    this list of conditions and the following disclaimer in the documentation
+*    and/or other materials provided with the distribution.
+* 
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "GhettoCrypt.h"
+
+/*** ./../GhettoCrypt/Cipher.cpp ***/
+
+#include <iostream>
+
+GhettoCipher::Cipher::Cipher(const Block& key)
+	:
+	key { key }
+{
+
+	return;
+}
+
+GhettoCipher::Cipher::Cipher(const std::string& password)
+{
+	key = PasswordToKey(password);
+
+	return;
+}
+
+GhettoCipher::Cipher::~Cipher()
+{
+	// Clear key memory
+	ZeroKeyMemory();
+
+	return;
+}
+
+void GhettoCipher::Cipher::SetKey(const Block& key)
+{
+	ZeroKeyMemory();
+
+	this->key = key;
+	return;
+}
+
+void GhettoCipher::Cipher::SetPassword(const std::string& password)
+{
+	ZeroKeyMemory();
+
+	key = PasswordToKey(password);
+	return;
+}
+
+GhettoCipher::Flexblock GhettoCipher::Cipher::Encipher(const Flexblock& data, bool printProgress) const
+{
+	// Split cleartext into blocks
+	std::vector<Block> blocks;
+
+	for (std::size_t i = 0; i < data.size(); i += BLOCK_SIZE)
+		blocks.push_back(Block(
+			PadStringToLength(data.substr(i, BLOCK_SIZE), BLOCK_SIZE, '0', false))
+		);
+
+	// Encrypt individual blocks using cipher block chaining
+	Feistel feistel(key);
+
+	for (std::size_t i = 0; i < blocks.size(); i++)
+	{
+		// Print reports if desired. If we have > 1000 blocks, print one report every 100 blocks. Otherwise for every 10th block.
+		if ((i % ((blocks.size() > 1000)? 100 : 10) == 0) && (printProgress))
+			std::cout << "Encrypting... (Block " << i << " / " << blocks.size() << " - " << ((float)i*100 / blocks.size()) << "%)" << std::endl;
+	
+		const Block& lastBlock = (i>0) ? blocks[i-1] : emptyBlock;
+		blocks[i] = feistel.Encipher(blocks[i] ^ lastBlock);
+	}
+
+	// Concatenate ciphertext blocks back into a flexblock
+	std::stringstream ss;
+	for (Block& b : blocks)
+		ss << b;
+
+	// Return it
+	return ss.str();
+}
+
+GhettoCipher::Flexblock GhettoCipher::Cipher::Decipher(const Flexblock& data, bool printProgress) const
+{
+	// Split ciphertext into blocks
+	std::vector<Block> blocks;
+
+	for (std::size_t i = 0; i < data.size(); i += BLOCK_SIZE)
+		blocks.push_back(Block(
+			PadStringToLength(data.substr(i, BLOCK_SIZE), BLOCK_SIZE, '0', false))
+		);
+
+	// Decrypt individual blocks
+	Feistel feistel(key);
+
+	// We can't do this in-loop for decryption, because we are decrypting the blocks in-place.
+	Block lastBlock = emptyBlock;
+	
+	for (std::size_t i = 0; i < blocks.size(); i++)
+	{
+		// Print reports if desired. If we have > 1000 blocks, print one report every 100 blocks. Otherwise for every 10th block.
+		if ((i % ((blocks.size() > 1000) ? 100 : 10) == 0) && (printProgress))
+			std::cout << "Decrypting... (Block " << i << " / " << blocks.size() << " - " << ((float)i*100/ blocks.size()) << "%)" << std::endl;
+
+		Block tmpCopy = blocks[i];
+
+		blocks[i] = feistel.Decipher(blocks[i]) ^ lastBlock;
+
+		lastBlock = std::move(tmpCopy);
+	}
+
+	// Concatenate ciphertext blocks back into a flexblock
+	std::stringstream ss;
+	for (Block& b : blocks)
+		ss << b;
+
+	// Return it
+	return ss.str();
+}
+
+#if defined _WIN32 || defined _WIN64
+#pragma optimize("", off )
+#endif
+void GhettoCipher::Cipher::ZeroKeyMemory()
+{
+	key.reset();
+	return;
+}
+#if defined _WIN32 || defined _WIN64
+#pragma optimize("", on )
+#endif
+
+const GhettoCipher::Block GhettoCipher::Cipher::emptyBlock;
+
+
+/*** ./../GhettoCrypt/Feistel.cpp ***/
+
+
+GhettoCipher::Feistel::Feistel(const Block& key)
+{
+    SetKey(key);
+    return;
+}
+
+GhettoCipher::Feistel::~Feistel()
+{
+    ZeroKeyMemory();
+
+    return;
+}
+
+void GhettoCipher::Feistel::SetKey(const Block& key)
+{
+    GenerateRoundKeys(key);
+    return;
+}
+
+GhettoCipher::Block GhettoCipher::Feistel::Encipher(const Block& data) const
+{
+    return Run(data, false);
+}
+
+GhettoCipher::Block GhettoCipher::Feistel::Decipher(const Block& data) const
+{
+    return Run(data, true);
+}
+
+GhettoCipher::Block GhettoCipher::Feistel::Run(const Block& data, bool reverseKeys) const
+{
+    const auto splitData = FeistelSplit(data);
+    GhettoCipher::Halfblock l = splitData.first;
+    GhettoCipher::Halfblock r = splitData.second;
+
+    Halfblock tmp;
+
+    for (std::size_t i = 0; i < N_ROUNDS; i++)
+    {
+        // Calculate key index
+        std::size_t keyIndex;
+        if (reverseKeys)
+            keyIndex = N_ROUNDS - i - 1;
+        else
+            keyIndex = i;
+
+        // Do a feistel round
+        tmp = r;
+        r = l ^ F(r, roundKeys[keyIndex]);
+        l = tmp;
+    }
+
+    return FeistelCombine(r, l);
+}
+
+GhettoCipher::Halfblock GhettoCipher::Feistel::F(Halfblock m, const Block& key)
+{
+    // Made-up F function
+
+    // Expand to full bitwidth
+    Block m_expanded = ExpansionFunction(m);
+
+    // Shift to left by 1
+    m_expanded = Shiftl(m_expanded, 1);
+
+    // Xor with key
+    m_expanded ^= key;
+
+    // Non-linearly apply subsitution boxes
+    std::stringstream ss;
+    const std::string m_str = m_expanded.to_string();
+
+    for (std::size_t i = 0; i < m_str.size(); i += 4)
+    {
+        ss << SBox(m_str.substr(i, 4));
+    }
+
+    m_expanded = Block(ss.str());
+
+    // Return the compressed version
+    return CompressionFunction(m_expanded);
+}
+
+std::pair<GhettoCipher::Halfblock, GhettoCipher::Halfblock> GhettoCipher::Feistel::FeistelSplit(const Block& block)
+{
+    const std::string bits = block.to_string();
+
+    Halfblock l(bits.substr(0, bits.size() / 2));
+    Halfblock r(bits.substr(bits.size() / 2));
+
+    return std::make_pair(l, r);
+}
+
+GhettoCipher::Block GhettoCipher::Feistel::FeistelCombine(const Halfblock& l, const Halfblock& r)
+{
+    return Block(l.to_string() + r.to_string());
+}
+
+GhettoCipher::Block GhettoCipher::Feistel::ExpansionFunction(const Halfblock& block)
+{
+    std::stringstream ss;
+    const std::string bits = block.to_string();
+
+    // We have to double the bits!
+    for (std::size_t i = 0; i < bits.size(); i += 2)
+    {
+        const std::string sub = bits.substr(i, 2);
+
+             if (sub == "00") ss << "1101";
+        else if (sub == "01") ss << "1000";
+        else if (sub == "10") ss << "0010";
+        else if (sub == "11") ss << "0111";
+
+    }
+
+    return Block(ss.str());
+}
+
+GhettoCipher::Halfblock GhettoCipher::Feistel::CompressionFunction(const Block& block)
+{
+    std::stringstream ss;
+    const std::string bits = block.to_string();
+
+    // We have to double the bits!
+    for (std::size_t i = 0; i < bits.size(); i += 4)
+    {
+        const std::string sub = bits.substr(i, 4);
+
+             if (sub == "0000") ss << "10";
+        else if (sub == "0001") ss << "01";
+        else if (sub == "0010") ss << "10";
+        else if (sub == "0011") ss << "10";
+        else if (sub == "0100") ss << "11";
+        else if (sub == "0101") ss << "01";
+        else if (sub == "0110") ss << "00";
+        else if (sub == "0111") ss << "11";
+        else if (sub == "1000") ss << "01";
+        else if (sub == "1001") ss << "00";
+        else if (sub == "1010") ss << "11";
+        else if (sub == "1011") ss << "00";
+        else if (sub == "1100") ss << "11";
+        else if (sub == "1101") ss << "10";
+        else if (sub == "1110") ss << "00";
+        else if (sub == "1111") ss << "01";
+    }
+
+    return Halfblock(ss.str());
+}
+
+std::string GhettoCipher::Feistel::SBox(const std::string& in)
+{
+         if (in == "0000")     return "1100";
+    else if (in == "0001")     return "1000";
+    else if (in == "0010")     return "0001";
+    else if (in == "0011")     return "0111";
+    else if (in == "0100")     return "1011";
+    else if (in == "0101")     return "0011";
+    else if (in == "0110")     return "1101";
+    else if (in == "0111")     return "1111";
+    else if (in == "1000")     return "0000";
+    else if (in == "1001")     return "1010";
+    else if (in == "1010")     return "0100";
+    else if (in == "1011")     return "1001";
+    else if (in == "1100")     return "0010";
+    else if (in == "1101")     return "1110";
+    else if (in == "1110")     return "0101";
+    else /*if (in == "1111")*/ return "0110";
+}
+
+void GhettoCipher::Feistel::GenerateRoundKeys(const Block& seedKey)
+{
+    // Generate round keys via output feedback modus (OFM) method
+
+    // Clear initial key memory
+    ZeroKeyMemory();
+    roundKeys = Keyset();
+
+    // Generate new keys from the seed key
+    roundKeys[0] = seedKey;
+    roundKeys[1] = (Shiftl(seedKey, 32) ^ roundKeys[0]);
+
+    for (std::size_t i = 2; i < roundKeys.size(); i++)
+    {
+        roundKeys[i] = Shiftl(roundKeys[i - 1], i + 32) ^ roundKeys[i - 2];
+    }
+
+    return;
+}
+
+// These pragmas only work for MSVC, as far as i know. Beware!!!
+#if defined _WIN32 || defined _WIN64
+#pragma optimize("", off )
+#endif
+void GhettoCipher::Feistel::ZeroKeyMemory()
+{
+    for (Block& key : roundKeys)
+        key.reset();
+
+    return;
+}
+#if defined _WIN32 || defined _WIN64
+#pragma optimize("", on )
+#endif
+
+
+/*** ./../GhettoCrypt/GhettoCryptWrapper.cpp ***/
+
+
+std::string GhettoCipher::GhettoCryptWrapper::EncryptString(const std::string& cleartext, const std::string& password)
+{
+	// Instanciate our cipher and supply a key
+	Cipher cipher(password);
+
+	// Recode the ascii-string to bits
+	const Flexblock cleartext_bits = StringToBits(cleartext);
+
+	// Encrypt our cleartext bits
+	const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
+
+	// Recode the ciphertext bits to a hex-string
+	const std::string ciphertext = BitsToHexstring(ciphertext_bits);
+
+	// Return it
+	return ciphertext;
+}
+
+std::string GhettoCipher::GhettoCryptWrapper::DecryptString(const std::string& ciphertext, const std::string& password)
+{
+	// Instanciate our cipher and supply a key
+	Cipher cipher(password);
+
+	// Recode the hex-string to bits
+	const Flexblock ciphertext_bits = HexstringToBits(ciphertext);
+
+	// Decrypt the ciphertext bits
+	const std::string cleartext_bits = cipher.Decipher(ciphertext_bits);
+
+	// Recode the cleartext bits to an ascii-string
+	const std::string cleartext = BitsToString(cleartext_bits);
+
+	// Return it
+	return cleartext;
+}
+
+bool GhettoCipher::GhettoCryptWrapper::EncryptFile(const std::string& filename_in, const std::string& filename_out, const std::string& password)
+{
+	try
+	{
+		// Read the file to bits
+		const Flexblock cleartext_bits = ReadFileToBits(filename_in);
+
+		// Instanciate our cipher and supply a key
+		Cipher cipher(password);
+
+		// Encrypt our cleartext bits
+		const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
+
+		// Write our ciphertext bits to file
+		WriteBitsToFile(filename_out, ciphertext_bits);
+
+		return true;
+	}
+	catch (std::runtime_error&)
+	{
+		return false;
+	}
+}
+
+bool GhettoCipher::GhettoCryptWrapper::DecryptFile(const std::string& filename_in, const std::string& filename_out, const std::string& password)
+{
+	try
+	{
+		// Read the file to bits
+		const Flexblock ciphertext_bits = ReadFileToBits(filename_in);
+
+		// Instanciate our cipher and supply a key
+		Cipher cipher(password);
+
+		// Decrypt the ciphertext bits
+		const Flexblock cleartext_bits = cipher.Decipher(ciphertext_bits);
+
+		// Write our cleartext bits to file
+		WriteBitsToFile(filename_out, cleartext_bits);
+
+		return true;
+	}
+	catch (std::runtime_error&)
+	{
+		return false;
+	}
+}
+

INCLUDE/GhettoCrypt.h

@@ -0,0 +1,475 @@
+/*
+* BSD 2-Clause License
+* 
+* Copyright (c) 2021, Leon Etienne
+* All rights reserved.
+* 
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+* 
+* 1. Redistributions of source code must retain the above copyright notice, this
+*    list of conditions and the following disclaimer.
+* 
+* 2. Redistributions in binary form must reproduce the above copyright notice,
+*    this list of conditions and the following disclaimer in the documentation
+*    and/or other materials provided with the distribution.
+* 
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#pragma once
+
+/*** ./../GhettoCrypt/GhettoCryptWrapper.h ***/
+
+#pragma once
+#include <string>
+
+namespace GhettoCipher
+{
+	/** This class is a wrapper to make working with the GhettoCipher super easy with a python-like syntax
+	*/
+	class GhettoCryptWrapper
+	{
+	public:
+		//! Will encrypt a string and return it hexadecimally encoded.
+		static std::string EncryptString(const std::string& cleartext, const std::string& password);
+
+		//! Will decrypt a hexadecimally encoded string.
+		static std::string DecryptString(const std::string& ciphertext, const std::string& password);
+
+		//! Will encrypt a file.
+		//! Returns false if anything goes wrong (like, file-access).
+		//! @filename_in The file to be read.
+		//! @filename_out The file the encrypted version should be saved in.
+		static bool EncryptFile(const std::string& filename_in, const std::string& filename_out, const std::string& password);
+
+		//! Will decrypt a file.
+		//! Returns false if anything goes wrong (like, file-access).
+		//! @filename_in The file to be read.
+		//! @filename_out The file the decrypted version should be saved in.
+		static bool DecryptFile(const std::string& filename_in, const std::string& filename_out, const std::string& password);
+
+	private:
+		// No instanciation! >:(
+		GhettoCryptWrapper();
+	};
+}
+
+/*** ./../GhettoCrypt/Flexblock.h ***/
+
+#pragma once
+#include <vector>
+
+namespace GhettoCipher
+{
+	//! A "bitset" of variable length
+	typedef std::string Flexblock;
+}
+
+/*** ./../GhettoCrypt/Config.h ***/
+
+#pragma once
+
+namespace GhettoCipher
+{
+	constexpr int BLOCK_SIZE = 128;
+	constexpr int N_ROUNDS = 64;
+}
+
+/*** ./../GhettoCrypt/Halfblock.h ***/
+
+#pragma once
+#include <bitset>
+
+namespace GhettoCipher
+{
+	constexpr int HALFBLOCK_SIZE = (BLOCK_SIZE / 2);
+	typedef std::bitset<HALFBLOCK_SIZE> Halfblock;
+}
+
+/*** ./../GhettoCrypt/Block.h ***/
+
+#pragma once
+#include <bitset>
+
+namespace GhettoCipher
+{
+	typedef std::bitset<BLOCK_SIZE> Block;
+}
+
+/*** ./../GhettoCrypt/Util.h ***/
+
+#pragma once
+#include <bitset>
+#include <sstream>
+#include <fstream>
+
+namespace GhettoCipher
+{
+    //! Mod-operator that works with negative values
+    inline int Mod(int numerator, int denominator)
+    {
+        return (denominator + (numerator % denominator)) % denominator;
+    }
+
+    //! Will perform a wrapping left-bitshift on a bitset
+    template <std::size_t T>
+    inline std::bitset<T> Shiftl(const std::bitset<T>& bits, 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 std::bitset<T>(ss.str());
+    }
+
+    //! Will perform a wrapping right-bitshift on a bitset
+    template <std::size_t T>
+    inline std::bitset<T> Shiftr(const std::bitset<T>& bits, 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 std::bitset<T>(ss.str());
+    }
+
+    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 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 data block to a string
+    inline std::string BitblockToString(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 flexible data block to a string
+    inline std::string BitsToString(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();
+    }
+
+    //! Turns a fixed 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 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 = (c - '0') + 0;
+            else if ((c >= 'a') && (c <= 'f'))
+                // Else, it is a lowercase letter
+                value = (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 = (c - '0') + 0;
+            else if ((c >= 'a') && (c <= 'f'))
+                // Else, it is a lowercase letter
+                value = (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 key-size from a password of arbitrary length.
+    inline Block PasswordToKey(const std::string& in)
+    {
+        Block b;
+
+        // 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)
+            b ^= StringToBitblock(in.substr(i, BLOCK_SIZE / 8));
+
+        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 = BitsToString(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;
+    }
+}
+
+/*** ./../GhettoCrypt/Keyset.h ***/
+
+#pragma once
+#include <array>
+
+namespace GhettoCipher
+{
+	typedef std::array<Block, N_ROUNDS> Keyset;
+}
+
+/*** ./../GhettoCrypt/Feistel.h ***/
+
+#pragma once
+
+namespace GhettoCipher
+{
+	/** Class to perform a feistel block chipher
+	*/
+	class Feistel
+	{
+	public:
+		explicit Feistel(const Block& key);
+
+		Feistel(const Feistel& other) = delete;
+		Feistel(Feistel&& other) noexcept = delete;
+
+		~Feistel();
+
+		//! Will set the seed-key for this feistel network.
+		//! Roundkeys will be derived from this.
+		void SetKey(const Block& key);
+
+		//! Will encipher a data block via the set seed-key
+		Block Encipher(const Block& data) const;
+
+		//! Will decipher a data block via the set seed-key
+		Block Decipher(const Block& data) const;
+
+	private:
+		//! Will run the feistel rounds, with either regular key order or reversed key order
+		Block Run(const Block& data, bool reverseKeys) const;
+
+		//! Arbitrary cipher function
+		static Halfblock F(Halfblock m, const Block& key);
+
+		//! Split a data block into two half blocks (into L and R)
+		static std::pair<Halfblock, Halfblock> FeistelSplit(const Block& block);
+
+		//! Combine two half blocks (L and R) into a regular data block
+		static Block FeistelCombine(const Halfblock& l, const Halfblock& r);
+
+		//! Will expand a halfblock to a fullblock
+		static Block ExpansionFunction(const Halfblock& block);
+
+		//! Will compress a fullblock to a halfblock
+		static Halfblock CompressionFunction(const Block& block);
+
+		//! Substitutes four bits by static random others
+		static std::string SBox(const std::string& in);
+
+		//! Will generate a the round keys
+		void GenerateRoundKeys(const Block& seedKey);
+
+		//! Will zero the memory used by the keyset
+		void ZeroKeyMemory();
+
+		Keyset roundKeys;
+	};
+}
+
+/*** ./../GhettoCrypt/Cipher.h ***/
+
+#pragma once
+
+namespace GhettoCipher
+{
+	/** Class to apply a block cipher to messages of arbitrary length in a distributed manner
+	*/
+	class Cipher
+	{
+	public:
+		explicit Cipher(const Block& key);
+		explicit Cipher(const std::string& password);
+
+		Cipher(const Cipher& other) = delete;
+		Cipher(Cipher&& other) noexcept = delete;
+
+		~Cipher();
+
+		//! Will set the key
+		void SetKey(const Block& key);
+
+		//! Will set the key from a password
+		void SetPassword(const std::string& password);
+
+		//! Will encipher a flexblock of data
+		Flexblock Encipher(const Flexblock& data, bool printProgress = false) const;
+
+		//! Will decipher a flexblock of data
+		Flexblock Decipher(const Flexblock& data, bool printProgress = false) const;
+
+	private:
+		Block key;
+
+		//! Will zero the memory used by the key
+		void ZeroKeyMemory();
+
+		// Initial value for cipher block chaining
+		static const Block emptyBlock;
+	};
+}