/// <summary>Generate a random SHA3 Hash/Key as String.</summary>
/// <remarks>Generate a random SHA3 Hash/Key as String.</remarks>
/// <param name="keySize">Size of hash. Allowed are 224, 256, 384 and 512.</param>
/// <returns>SHA3 hash as Hex String</returns>
public virtual string generateKey(int keySize)
{
SecureRandom scRandom = new SecureRandom();
byte[] randomPW = new byte[40];
scRandom.nextBytes(randomPW);
KeyGenSHA3.init(keySize);
KeyGenSHA3.update(randomPW, randomPW.Length * 8);
string output = CryptobyHelper.bytesToHexString(KeyGenSHA3.getHash());
return output;
}
/// <summary>Encrypt a byte array in blocks with AES algorithm in CBC mode.</summary>
/// <remarks>Encrypt a byte array in blocks with AES algorithm in CBC mode.</remarks>
/// <param name="plainInput">Plain byte array to encrypt</param>
/// <param name="key">256 Bit key to encrypt plainInput</param>
/// <returns>Return encrypted byte array</returns>
public virtual byte[] encrypt(byte[] plainInput, byte[] key)
{
int inputLength = plainInput.Length;
int percentProgress;
int prevPercent = -1;
byte[] inputLengthByte = ByteBuffer.allocate (4).order (ByteOrder.BIG_ENDIAN).putInt (inputLength).array ();
int restInput = plainInput.Length % nBytes;
byte[] exKey = initKeyExpand(key);
byte[] cipher = new byte[nBytes];
byte[] cryptOutput = new byte[(inputLength - restInput) + nBytes * 2];
int outputLength = cryptOutput.Length;
byte[] initVector = new byte[nBytes];
byte[] nextBlock = new byte[nBytes];
SecureRandom scRandom = new SecureRandom();
// Copy plaintext Array into crypt Array
System.Array.Copy(plainInput, 0, cryptOutput, 0, inputLength);
// Fill Initialization Vector with Random Bytes
scRandom.nextBytes(initVector);
// Copy first Input Block to nextBlock
System.Array.Copy(cryptOutput, 0, nextBlock, 0, nBytes);
// XOR Random initVektor with first Input Block
nextBlock = CryptobyHelper.xorByteArrays(nextBlock, initVector);
// Copy xored prevBlock into first Input Block
System.Array.Copy(nextBlock, 0, cryptOutput, 0, nBytes);
// Encrypt last BlockArray
initVector = encryptCipher (initVector, exKey);
// Add the initVector Array in to last BlockArray and encrypt it
System.Array.Copy(initVector, 0, cryptOutput, outputLength - nBytes, nBytes);
// Add in the first Byte after CryptText the origin length of plaintext Array
System.Array.Copy(inputLengthByte, 0, cryptOutput, outputLength - nBytes * 2, 4);
// Encrypt every Block in CBC Mode
for (int i = 0; i < outputLength - nBytes; i += nBytes)
{
// Convert i to percent for ProgressBar
// percentProgress = (int)(((float)i / (float)(outputLength - nBytes)) * 100);
// // Print ProgressBar
// if (percentProgress > prevPercent)
// {
// CryptobyHelper.printProgressBar(percentProgress);
// }
// prevPercent = percentProgress;
// Copy current block in to Cipher Array
System.Array.Copy(nextBlock, 0, cipher, 0, nBytes);
// Encrypt Cipher
cipher = this.encryptCipher(cipher, exKey);
// CBC Mode: XOR next PlainBlock with encrypted Cipher
if (i + nBytes < outputLength)
{
System.Array.Copy(cryptOutput, i + nBytes, nextBlock, 0, nBytes);
nextBlock = CryptobyHelper.xorByteArrays(nextBlock, cipher);
}
// Copy Cipher back in decryptOutput Array
System.Array.Copy(cipher, 0, cryptOutput, i, nBytes);
}
// CryptobyHelper.printProgressBar(100);
return cryptOutput;
}
/// <summary>Generate a random SHA3 Hash/Key as byte array.</summary>
/// <remarks>Generate a random SHA3 Hash/Key as byte array.</remarks>
/// <param name="keySize">Size of hash. Allowed are 224, 256, 384 and 512.</param>
/// <returns>SHA3 hash as byte array</returns>
public virtual byte[] generateKeyByte(int keySize)
{
SecureRandom scRandom = new SecureRandom();
byte[] randomPW = new byte[40];
scRandom.nextBytes(randomPW);
KeyGenSHA3.init(keySize);
KeyGenSHA3.update(randomPW, randomPW.Length * 8);
byte[] output = KeyGenSHA3.getHash();
return output;
}
