Made the whole thing MUCH more secure, by adding an IV (initialization vector), implemeted RRKM (rolling round key mode) and redone key extrapolation

ExampleApp/.gitignore

@@ -0,0 +1,2 @@
+/main.cpp.crypt
+/main.cpp.clear

ExampleApp/main.cpp

@@ -12,7 +12,7 @@ void ExampleString()
 	std::cout << "Example on how to encrypt & decrypt a string:" << std::endl;
 
 	// Get some string
-	const std::string input = "I am a super secret message!";
+	const std::string input = "I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!I am a super secret message!";
 	std::cout << input << std::endl;
 
 	// Encrypt

GhettoCrypt/Cipher.cpp

@@ -65,7 +65,7 @@ GhettoCipher::Flexblock GhettoCipher::Cipher::Encipher(const Flexblock& data, bo
 			std::cout << "Encrypting... (Block " << i << " / " << blocks.size() << " - " << ((float)i*100 / blocks.size()) << "%)" << std::endl;
 	
 		const Block& lastBlock = (i>0) ? blocks[i-1] : initializationVector;
-		blocks[i] = feistel.Encipher(blocks[i] ^ lastBlock);
+		blocks[i] = feistel.Encipher(blocks[i] ^ lastBlock); // Xor last cipher block with new clear text block before E()
 	}
 
 	// Concatenate ciphertext blocks back into a flexblock
@@ -101,7 +101,7 @@ GhettoCipher::Flexblock GhettoCipher::Cipher::Decipher(const Flexblock& data, bo
 
 		Block tmpCopy = blocks[i];
 
-		blocks[i] = feistel.Decipher(blocks[i]) ^ lastBlock;
+		blocks[i] = feistel.Decipher(blocks[i]) ^ lastBlock; // Decipher cipher block [i] and then xor it with the last cipher block [i-1] we've had
 
 		lastBlock = std::move(tmpCopy);
 	}

GhettoCrypt/Cipher.h

@@ -36,6 +36,6 @@ namespace GhettoCipher
 		void ZeroKeyMemory();
 
 		// Initial value for cipher block chaining
-		const Block initializationVector;
+		Block initializationVector;
 	};
 }

GhettoCrypt/Feistel.cpp

@@ -22,17 +22,17 @@ void GhettoCipher::Feistel::SetKey(const Block& key)
     return;
 }
 
-GhettoCipher::Block GhettoCipher::Feistel::Encipher(const Block& data) const
+GhettoCipher::Block GhettoCipher::Feistel::Encipher(const Block& data)
 {
     return Run(data, false);
 }
 
-GhettoCipher::Block GhettoCipher::Feistel::Decipher(const Block& data) const
+GhettoCipher::Block GhettoCipher::Feistel::Decipher(const Block& data)
 {
     return Run(data, true);
 }
 
-GhettoCipher::Block GhettoCipher::Feistel::Run(const Block& data, bool reverseKeys) const
+GhettoCipher::Block GhettoCipher::Feistel::Run(const Block& data, bool reverseKeys)
 {
     const auto splitData = FeistelSplit(data);
     GhettoCipher::Halfblock l = splitData.first;
@@ -55,6 +55,10 @@ GhettoCipher::Block GhettoCipher::Feistel::Run(const Block& data, bool reverseKe
         l = tmp;
     }
 
+    // Block has finished de*ciphering.
+    // Let's generate a new set of round keys.
+    GenerateRoundKeys((Block)roundKeys.back());
+
     return FeistelCombine(r, l);
 }
 
@@ -75,7 +79,7 @@ GhettoCipher::Halfblock GhettoCipher::Feistel::F(Halfblock m, const Block& key)
     std::stringstream ss;
     const std::string m_str = m_expanded.to_string();
 
-    for (std::size_t i = 0; i < m_str.size(); i += 4)
+    for (std::size_t i = 0; i < BLOCK_SIZE; i += 4)
     {
         ss << SBox(m_str.substr(i, 4));
     }
@@ -113,7 +117,7 @@ GhettoCipher::Block GhettoCipher::Feistel::ExpansionFunction(const Halfblock& bl
     expansionMap["11"] = "0111";
 
     // We have to double the bits!
-    for (std::size_t i = 0; i < bits.size(); i += 2)
+    for (std::size_t i = 0; i < HALFBLOCK_SIZE; i += 2)
     {
         const std::string sub = bits.substr(i, 2);
         ss << expansionMap[sub];
@@ -146,7 +150,7 @@ GhettoCipher::Halfblock GhettoCipher::Feistel::CompressionFunction(const Block&
     compressionMap["1111"] = "01";
 
     // We have to half the bits!
-    for (std::size_t i = 0; i < bits.size(); i += 4)
+    for (std::size_t i = 0; i < BLOCK_SIZE; i += 4)
     {
         const std::string sub = bits.substr(i, 4);
         ss << compressionMap[sub];
@@ -185,19 +189,67 @@ std::string GhettoCipher::Feistel::SBox(const std::string& in)
 
 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
+    // Derive the initial two round keys
-    roundKeys[0] = seedKey;
+
-    roundKeys[1] = (Shiftl(seedKey, 32) ^ roundKeys[0]);
+    // Compress- substitute, and expand the seed key to form the initial and the second-initial round key
+    // This action is non-linear and irreversible, and thus strenghtens security.
+    Halfblock compressedSeed1 = CompressionFunction(seedKey);
+    Halfblock compressedSeed2 = CompressionFunction(Shiftl(seedKey, 1)); // Shifting one key by 1 will result in a completely different compression
+
+    // To add further confusion, let's shift seed1 by 1 aswell (after compression, but before substitution)
+    // but only if the total number of bits set are a multiple of 3
+    // if it is a multiple of 4, we'll shift it by 1 into the opposite direction
+    const std::size_t setBits1 = compressedSeed1.count();
+
+    if (setBits1 % 4 == 0)
+        compressedSeed1 = Shiftr(compressedSeed1, 1);
+    else if (setBits1 % 3 == 0)
+        compressedSeed1 = Shiftl(compressedSeed1, 1);
+
+    // Now apply substitution
+    std::stringstream ssKey1;
+    std::stringstream ssKey2;
+    const std::string bitsKey1 = compressedSeed1.to_string();
+    const std::string bitsKey2 = compressedSeed2.to_string();
+
+    for (std::size_t i = 0; i < HALFBLOCK_SIZE; i += 4)
+    {
+        ssKey1 << SBox(bitsKey1.substr(i, 4));
+        ssKey2 << SBox(bitsKey2.substr(i, 4));
+    }
+
+    compressedSeed1 = Halfblock(ssKey1.str());
+    compressedSeed2 = Halfblock(ssKey2.str());
+
+    // Now extrapolate them to BLOCK_SIZE (key size) again
+    // Xor with the original seed key to get rid of the repititions caused by the expansion
+    roundKeys[0] = ExpansionFunction(compressedSeed1) ^ seedKey;
+    roundKeys[1] = ExpansionFunction(compressedSeed2) ^ seedKey;
+
+    
+    // Now derive all other round keys
 
     for (std::size_t i = 2; i < roundKeys.size(); i++)
     {
-        roundKeys[i] = Shiftl(roundKeys[i - 1], i + 32) ^ roundKeys[i - 2];
+        // Initialize new round key with last round key
+        Block newKey = roundKeys[i - 1];
+
+        // Shift to left by how many bits are set, modulo 8
+        newKey = Shiftl(newKey, newKey.count() % 8); // This action is irreversible
+
+        // Split into two halfblocks,
+        // apply F() to one halfblock with rk[i-2],
+        // xor the other one with it
+        // and put them back together
+        auto halfkeys = FeistelSplit(newKey);
+        Halfblock halfkey1 = F(halfkeys.first, roundKeys[i - 2]);
+        Halfblock halfkey2 = halfkeys.second ^ halfkey1;
+
+        roundKeys[i] = FeistelCombine(halfkey1, halfkey2);
     }
 
     return;

GhettoCrypt/Feistel.h

@@ -22,14 +22,14 @@ namespace GhettoCipher
 		void SetKey(const Block& key);
 
 		//! Will encipher a data block via the set seed-key
-		Block Encipher(const Block& data) const;
+		Block Encipher(const Block& data);
 
 		//! Will decipher a data block via the set seed-key
-		Block Decipher(const Block& data) const;
+		Block Decipher(const Block& data);
 
 	private:
 		//! Will run the feistel rounds, with either regular key order or reversed key order
-		Block Run(const Block& data, bool reverseKeys) const;
+		Block Run(const Block& data, bool reverseKeys);
 
 		//! Arbitrary cipher function
 		static Halfblock F(Halfblock m, const Block& key);

GhettoCrypt/GhettoCryptWrapper.cpp

@@ -1,11 +1,13 @@
 #include "GhettoCryptWrapper.h"
 #include "Cipher.h"
 #include "Util.h"
+#include <iostream>
 
 std::string GhettoCipher::GhettoCryptWrapper::EncryptString(const std::string& cleartext, const std::string& password)
 {
 	// Instanciate our cipher and supply a key
-	Cipher cipher(password);
+	const Block key = PasswordToKey(password);
+	Cipher cipher(key);
 
 	// Recode the ascii-string to bits
 	const Flexblock cleartext_bits = StringToBits(cleartext);
@@ -23,7 +25,8 @@ std::string GhettoCipher::GhettoCryptWrapper::EncryptString(const std::string& c
 std::string GhettoCipher::GhettoCryptWrapper::DecryptString(const std::string& ciphertext, const std::string& password)
 {
 	// Instanciate our cipher and supply a key
-	Cipher cipher(password);
+	const Block key = PasswordToKey(password);
+	Cipher cipher(key);
 
 	// Recode the hex-string to bits
 	const Flexblock ciphertext_bits = HexstringToBits(ciphertext);
@@ -46,7 +49,8 @@ bool GhettoCipher::GhettoCryptWrapper::EncryptFile(const std::string& filename_i
 		const Flexblock cleartext_bits = ReadFileToBits(filename_in);
 
 		// Instanciate our cipher and supply a key
-		Cipher cipher(password);
+		const Block key = PasswordToKey(password);
+		Cipher cipher(key);
 
 		// Encrypt our cleartext bits
 		const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits, printProgressReport);
@@ -70,7 +74,8 @@ bool GhettoCipher::GhettoCryptWrapper::DecryptFile(const std::string& filename_i
 		const Flexblock ciphertext_bits = ReadFileToBits(filename_in);
 
 		// Instanciate our cipher and supply a key
-		Cipher cipher(password);
+		const Block key = PasswordToKey(password);
+		Cipher cipher(key);
 
 		// Decrypt the ciphertext bits
 		const Flexblock cleartext_bits = cipher.Decipher(ciphertext_bits, printProgressReport);

GhettoCrypt/InitializationVector.cpp

@@ -2,9 +2,18 @@
 #include <random>
 #include <sstream>
 
-using namespace GhettoCipher;
+// It would be REALLY BAD if another compiler/*version would use
+// a mersenne twister with different attrbitutes. It would basically mean
+// that E_machine1(M,K) != E_machine2(M,K), which would make them incompatible.
+// We do NOT want this to happen, so let's be VERY specific about what mersenne twister setup we want.
+// This is std::mt19937, as of msvc stl.
+using Prng_MT = std::mersenne_twister_engine<
+	unsigned int,
+	32, 624, 397, 31, 0x9908b0df, 11, 0xffffffff,
+	7, 0x9d2c5680, 15,0xefc60000, 18, 1812433253
+>;
 
-InitializationVector::InitializationVector(const Block& seed)
+GhettoCipher::InitializationVector::InitializationVector(const Block& seed)
 {
 	// Since an initialization vector does not have to be a secret,
 	// we should be fine just using a mersenne twister seeded with
@@ -12,8 +21,7 @@ InitializationVector::InitializationVector(const Block& seed)
 
 	// Loosely seed mersenne twister with seed
 	// Here is nothing copied. Both Block::Get, and Hash<>::operator() take refs.
-	std::mt19937 mt = std::mt19937(std::hash<std::bitset<BLOCK_SIZE>>()(seed.Get()));
+	Prng_MT mt = Prng_MT(std::hash<std::bitset<BLOCK_SIZE>>()(seed.Get()));
-
 	// Now generate BLOCK_SIZE urandom bits
 	std::stringstream ss;
 	for (std::size_t i = 0; i < BLOCK_SIZE; i++)
@@ -23,7 +31,7 @@ InitializationVector::InitializationVector(const Block& seed)
 	iv = Block(ss.str());
 }
 
-InitializationVector::operator GhettoCipher::Block() const
+GhettoCipher::InitializationVector::operator GhettoCipher::Block() const
 {
 	return iv;
 }

GhettoCrypt/InitializationVector.h

@@ -2,15 +2,18 @@
 #include "Config.h"
 #include "Block.h"
 
-/** Will create a sudo-random Block based on a seed
+namespace GhettoCipher
-*/
-class InitializationVector
 {
-public:
+	/** Will create a sudo-random Block based on a seed
+	*/
+	class InitializationVector
+	{
+	public:
 		InitializationVector(const GhettoCipher::Block& seed);
 
 		operator GhettoCipher::Block() const;
 
-private:
+	private:
 		GhettoCipher::Block iv;
-};
+	};
+}

GhettoCrypt/Util.h

@@ -5,6 +5,7 @@
 #include "SecureBitset.h"
 #include "Block.h"
 #include "Flexblock.h"
+#include "InitializationVector.h"
 
 namespace GhettoCipher
 {
@@ -90,8 +91,8 @@ namespace GhettoCipher
         return Flexblock(ss.str());
     }
 
-    //! Will convert a fixed-size data block to a string
+    //! Will convert a fixed-size data block to a bytestring
-    inline std::string BitblockToString(const Block& bits)
+    inline std::string BitblockToBytes(const Block& bits)
     {
         std::stringstream ss;
 
@@ -102,7 +103,15 @@ namespace GhettoCipher
             ss << (char)std::bitset<8>(bitstring.substr(i, 8)).to_ulong();
         }
 
-        std::string text = ss.str();
+        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()));
@@ -110,8 +119,8 @@ namespace GhettoCipher
         return text;
     }
 
-    //! Will convert a flexible data block to a string
+    //! Will convert a flexible data block to a bytestring
-    inline std::string BitsToString(const Flexblock& bits)
+    inline std::string BitsToBytes(const Flexblock& bits)
     {
         std::stringstream ss;
 
@@ -122,7 +131,15 @@ namespace GhettoCipher
             ss << (char)std::bitset<8>(bitstring.substr(i, 8)).to_ulong();
         }
 
-        std::string text = ss.str();
+        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()));
@@ -212,8 +229,10 @@ namespace GhettoCipher
     }
 
     //! Creates a key of size BLOCK_SIZE from a password of arbitrary length.
-    //! Using passwords larger (in bits) than BLOCK_SIZE is not generally recommended.
+    //! Using passwords larger (in bits) than BLOCK_SIZE is generally not recommended.
-    //! Note that if your password is shorter (in bits) than BLOCK_SIZE, the rest of the key will be padded with 0x0. Further round-keys will be extrapolated though.
+    //! 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)
     {
         Block b;
@@ -224,7 +243,7 @@ namespace GhettoCipher
                 PadStringToLength(in.substr(i, BLOCK_SIZE / 8), BLOCK_SIZE / 8, 0, false)
             );
 
-        return b;
+        return b ^ InitializationVector(b);
     }
 
     //! Will read a file into a flexblock
@@ -255,7 +274,7 @@ namespace GhettoCipher
     inline void WriteBitsToFile(const std::string& filepath, const Flexblock& bits)
     {
         // Convert bits to bytes
-        const std::string bytes = BitsToString(bits);
+        const std::string bytes = BitsToBytes(bits);
 
         // Write bits to file
         std::ofstream ofs(filepath, std::ios::binary);

GhettoCrypt/Version.h

@@ -1,2 +1,2 @@
 #pragma once
-#define GHETTOCRYPT_VERSION 0.13
+#define GHETTOCRYPT_VERSION 0.2

SimpleTests/.gitignore

@@ -0,0 +1,2 @@
+/testfile.png.crypt
+/testfile.png.clear.png

SimpleTests/EncryptEqualsDecrypt.cpp

@@ -5,28 +5,31 @@
 using namespace Microsoft::VisualStudio::CppUnitTestFramework;
 using namespace GhettoCipher;
 
+// THESE TESTS ASSUME BLOCK_SIZE == 512
+
 namespace SimpleTests
 {
 	TEST_CLASS(EncryptEqualsDecrypt)
 	{
 	public:
 		
-		// Tests that a decrypted ciphertext equals its plaintrext version
+		// Tests that encrypting a message of exactly BLOCK_SIZE yields the exact message back
-		TEST_METHOD(tEncryptEqualsDecrypt)
+		TEST_METHOD(SingleBlock_NoPadding)
 		{
-			// Yes, this unit test should ideally exclude string conversions,
-			// But like this it's easier to see what it's doing
-
-			// Define basic input
-			const std::string cleartext = "Hello, World!";
-			const std::string password  = "1234";
-
-
 			// Instanciate our cipher and supply a key
-			const Cipher cipher(password);
+			const Block key = PasswordToKey("1234");
+			const Cipher cipher(key);
 
 			// Recode the ascii-string to bits
-			const Flexblock cleartext_bits = StringToBits(cleartext);
+			const Flexblock cleartext_bits =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100010000001011100010010001101111100100101100010001"
+				"0000011110010110111010110110111110011110011010001100100111110101";
 
 			// Encrypt our cleartext bits
 			const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
@@ -34,11 +37,194 @@ namespace SimpleTests
 			// Decipher it again
 			const Flexblock decryptedBits = cipher.Decipher(ciphertext_bits);
 
-			// Decode it back to ascii
+			// Assert that the decrypted text equals the plaintext
-			const std::string decryptedText = BitsToString(decryptedBits);
+			Assert::AreEqual(
+				cleartext_bits,
+				decryptedBits
+			);
+		}
+		
+		// Tests that encrypting a message of less than BLOCK_SIZE yields the exact message plus zero-padding back
+		TEST_METHOD(SingleBlock_Padding)
+		{
+			// Instanciate our cipher and supply a key
+			const Block key = PasswordToKey("1234");
+			const Cipher cipher(key);
+
+			// Recode the ascii-string to bits
+			const Flexblock cleartext_bits =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100";
+			
+			const Flexblock cleartext_bits_EXPECTED_RESULT =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100000000000000000000000000000000000000000000000000"
+				"0000000000000000000000000000000000000000000000000000000000000000";
+
+			// Encrypt our cleartext bits
+			const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
+			
+			// Decipher it again
+			const Flexblock decryptedBits = cipher.Decipher(ciphertext_bits);
 
 			// Assert that the decrypted text equals the plaintext
-			Assert::AreEqual(cleartext.length(), decryptedText.length());
+			Assert::AreEqual(
+				cleartext_bits_EXPECTED_RESULT,
+				decryptedBits
+			);
+		}
+		
+		// Tests that a decrypted ciphertext equals its plaintrext version, using a cleartext that requires A LOT of blocks
+		TEST_METHOD(MultiBlock_NoPadding)
+		{
+			// Instanciate our cipher and supply a key
+			const Block key = PasswordToKey("1234");
+			const Cipher cipher(key);
+
+			// Recode the ascii-string to bits
+			const Flexblock cleartext_bits =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100010000001011100010010001101111100100101100010001"
+				"0000011110010110111010110110111110011110011010001100100111110101"
+				"1000010010000000000100101011110001000101101101100000010011111011"
+				"1011111010110100100111100111110011100001111101111110000110001100"
+				"0001000111000111101110000111011011101010100010100101100111010100"
+				"0101111110110010110000111111011001101110101101100100100011000100"
+				"1000110010101001000100001001101000011111101011111100100000100101"
+				"1100001100111001011111001101000111011101011101000110010110110110"
+				"0111001010011010010000010110000110010101101100101110111100100011"
+				"0010111110011100010100000101100101110101101011110100100000110110"
+				"1001101110101001001111111000010100011100100000101000111101101111"
+				"0101111011110001101010111010001000111010101111001101100100100100"
+				"1110110111001100011010110000101000011001011100101100111101110000"
+				"1010101111011110000111011011011110000111010110110111111010101010"
+				"0111100101111001010111101000001010100000111010111100111011111001"
+				"0110111000000110100011011100101101010101101000010010011111100100"
+				"0010111000001011101110000110010011101001111010100111110111110101"
+				"1110111000000000101011000100101010000110110111101010011001111010"
+				"1101011110001110000011010111001100001100101000000101000101000010"
+				"0101000011011111010010110010000010101100001110011000110111110111"
+				"1110010101011110111001100010110101101011100111100011101010001011"
+				"0101110010100110101100111100010000111101111100000111000110110110"
+				"1001100111000000011010100000011101011000010010011010001011110000"
+				"1100100111111001001000011100110000011110001100000000010000001001"
+				"1110000000110010000010011010100011011011000000000111110000110111"
+				"0101110011001101010110010100011001110110000110010001100110011111";
+
+			// Encrypt our cleartext bits
+			const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
+
+			// Decipher it again
+			const Flexblock decryptedBits = cipher.Decipher(ciphertext_bits);
+
+			// Assert that the decrypted text equals the plaintext
+			Assert::AreEqual(
+				cleartext_bits,
+				decryptedBits
+			);
+		}
+
+		// Tests that a decrypted ciphertext equals its plaintrext version, using a cleartext that requires A LOT of blocks
+		TEST_METHOD(MultiBlock_Padding)
+		{
+			// Instanciate our cipher and supply a key
+			const Block key = PasswordToKey("1234");
+			const Cipher cipher(key);
+
+			// Recode the ascii-string to bits
+			const Flexblock cleartext_bits =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100010000001011100010010001101111100100101100010001"
+				"0000011110010110111010110110111110011110011010001100100111110101"
+				"1000010010000000000100101011110001000101101101100000010011111011"
+				"1011111010110100100111100111110011100001111101111110000110001100"
+				"0001000111000111101110000111011011101010100010100101100111010100"
+				"0101111110110010110000111111011001101110101101100100100011000100"
+				"1000110010101001000100001001101000011111101011111100100000100101"
+				"1100001100111001011111001101000111011101011101000110010110110110"
+				"0111001010011010010000010110000110010101101100101110111100100011"
+				"0010111110011100010100000101100101110101101011110100100000110110"
+				"1001101110101001001111111000010100011100100000101000111101101111"
+				"0101111011110001101010111010001000111010101111001101100100100100"
+				"1110110111001100011010110000101000011001011100101100111101110000"
+				"1010101111011110000111011011011110000111010110110111111010101010"
+				"0111100101111001010111101000001010100000111010111100111011111001"
+				"0110111000000110100011011100101101010101101000010010011111100100"
+				"0010111000001011101110000110010011101001111010100111110111110101"
+				"1110111000000000101011000100101010000110110111101010011001111010"
+				"1101011110001110000011010111001100001100101000000101000101000010"
+				"0101000011011111010010110010000010101100001110011000110111110111"
+				"1110010101011110111001100010110101101011100111100011101010001011"
+				"0101110010100110101100111100010000111101111100000111000110110110"
+				"1001100111000000011010100000011101011000010010011010001011110000"
+				"1100100111111001001000011100110000011110001100000000010000001001"
+				"11100000001100100000100110101000110110110000000001111100001";
+
+			const Flexblock cleartext_bits_EXPECTED_RESULT =
+				"1011110011010110000010110001111000111010111101001010100100011101"
+				"0101110101010010100000110100001000011000111010001001110101111111"
+				"1110110101100101110001010101011110001010000010111110011011010111"
+				"1100110100111000000011100101010100110010001110010011000010111001"
+				"0000010000010000011001111010011110111001000000000110101000110001"
+				"0110111110110110100000010100000011010001000011100100111001001011"
+				"1101100100000100010000001011100010010001101111100100101100010001"
+				"0000011110010110111010110110111110011110011010001100100111110101"
+				"1000010010000000000100101011110001000101101101100000010011111011"
+				"1011111010110100100111100111110011100001111101111110000110001100"
+				"0001000111000111101110000111011011101010100010100101100111010100"
+				"0101111110110010110000111111011001101110101101100100100011000100"
+				"1000110010101001000100001001101000011111101011111100100000100101"
+				"1100001100111001011111001101000111011101011101000110010110110110"
+				"0111001010011010010000010110000110010101101100101110111100100011"
+				"0010111110011100010100000101100101110101101011110100100000110110"
+				"1001101110101001001111111000010100011100100000101000111101101111"
+				"0101111011110001101010111010001000111010101111001101100100100100"
+				"1110110111001100011010110000101000011001011100101100111101110000"
+				"1010101111011110000111011011011110000111010110110111111010101010"
+				"0111100101111001010111101000001010100000111010111100111011111001"
+				"0110111000000110100011011100101101010101101000010010011111100100"
+				"0010111000001011101110000110010011101001111010100111110111110101"
+				"1110111000000000101011000100101010000110110111101010011001111010"
+				"1101011110001110000011010111001100001100101000000101000101000010"
+				"0101000011011111010010110010000010101100001110011000110111110111"
+				"1110010101011110111001100010110101101011100111100011101010001011"
+				"0101110010100110101100111100010000111101111100000111000110110110"
+				"1001100111000000011010100000011101011000010010011010001011110000"
+				"1100100111111001001000011100110000011110001100000000010000001001"
+				"1110000000110010000010011010100011011011000000000111110000100000"
+				"0000000000000000000000000000000000000000000000000000000000000000";
+
+			// Encrypt our cleartext bits
+			const Flexblock ciphertext_bits = cipher.Encipher(cleartext_bits);
+
+			// Decipher it again
+			const Flexblock decryptedBits = cipher.Decipher(ciphertext_bits);
+
+			// Assert that the decrypted text equals the plaintext
+			Assert::AreEqual(
+				cleartext_bits_EXPECTED_RESULT,
+				decryptedBits
+			);
 		}
 	};
 }

SimpleTests/GCWrapper.cpp

@@ -0,0 +1,81 @@
+#include "CppUnitTest.h"
+#include "../GhettoCrypt/GhettoCryptWrapper.h"
+#include "../GhettoCrypt/Flexblock.h"
+#include "../GhettoCrypt/Util.h"
+
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+using namespace GhettoCipher;
+
+namespace SimpleTests
+{
+	TEST_CLASS(GCWrapper)
+	{
+	public:
+
+		// Tests that encrypting and decrypting strings using the wrapper works.
+		// This test will start from scratch after encryption, to ensure EVERYTHING has to be re-calculated.
+		TEST_METHOD(String)
+		{
+			// Setup
+			const std::string plaintext = "Hello, World!";
+			const std::string password = "Der Affe will Zucker";
+
+			std::string ciphertext;
+			std::string decrypted;
+
+			// Encryption
+			{
+				ciphertext = GhettoCryptWrapper::EncryptString(plaintext, password);
+			}
+
+			// Decryption
+			{
+				decrypted = GhettoCryptWrapper::DecryptString(ciphertext, password);
+			}
+
+			// Assertion
+			Assert::AreEqual(
+				plaintext,
+				decrypted
+			);
+		}
+
+		// Tests that encrypting and decrypting files using the wrapper works.
+		// This test will start from scratch after encryption, to ensure EVERYTHING has to be re-calculated.
+		TEST_METHOD(File)
+		{
+			// Setup
+			#if defined _WIN64
+			const std::string testfile_dir = "../../SimpleTests/";
+			#elif defined _WIN32
+			const std::string testfile_dir = "../SimpleTests/";
+			#endif
+			
+			const std::string filename_plain	 = testfile_dir + "testfile.png";
+			const std::string filename_encrypted = testfile_dir + "testfile.png.crypt";
+			const std::string filename_decrypted = testfile_dir + "testfile.png.clear.png";
+			const std::string password = "Der Affe will Zucker";
+
+
+			// Encryption
+			{
+				GhettoCryptWrapper::EncryptFile(filename_plain, filename_encrypted, password);
+			}
+
+			// Decryption
+			{
+				GhettoCryptWrapper::DecryptFile(filename_encrypted, filename_decrypted, password);
+			}
+
+			// Read in both the base, and the decrypted file
+			const Flexblock plainfile = ReadFileToBits(filename_plain);
+			const Flexblock decryptfile = ReadFileToBits(filename_decrypted);
+
+			// Assertion (If this fails, maybe check if the image is even readable by an image viewer)
+			Assert::AreEqual(
+				PadStringToLength(plainfile, decryptfile.length(), '0', false),
+				decryptfile
+			);
+		}
+	};
+}

SimpleTests/SimpleTests.vcxproj

@@ -157,6 +157,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="EncryptEqualsDecrypt.cpp" />
+    <ClCompile Include="GCWrapper.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\GhettoCrypt\GhettoCrypt.vcxproj">

SimpleTests/SimpleTests.vcxproj.filters

@@ -18,5 +18,8 @@
     <ClCompile Include="EncryptEqualsDecrypt.cpp">
       <Filter>Quelldateien</Filter>
     </ClCompile>
+    <ClCompile Include="GCWrapper.cpp">
+      <Filter>Quelldateien</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>

readme.md

@@ -4,7 +4,7 @@
 
 ## What the hell is this?
 An educational project on implementing a block cipher using a feistel network.  
-To provide at least some security this is using some DES-inspired tactics like *cipher block chaining* and *output feedback modus*.
+To provide at least some security this is using some DES-inspired modes of operation like *cipher block chaining*.
 This way this provides relatively good diffusion.
 
 ## Features