RC.java

package cryptography.ciphers.rc;

import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;

import org.spongycastle.crypto.BlockCipher;
import org.spongycastle.crypto.BufferedBlockCipher;
import org.spongycastle.crypto.DataLengthException;
import org.spongycastle.crypto.InvalidCipherTextException;
import org.spongycastle.crypto.engines.RC2Engine;
import org.spongycastle.crypto.engines.RC4Engine;
import org.spongycastle.crypto.engines.RC6Engine;
import org.spongycastle.crypto.modes.CBCBlockCipher;
import org.spongycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.spongycastle.crypto.params.KeyParameter;

import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;
import cryptography.Mode;

public class RC {

	public static void main(String[] args) {
	}

	// Provider
	static {
		Security.insertProviderAt(new org.spongycastle.jce.provider.BouncyCastleProvider(), 1);
	}

	/**
	 * Source code:
	 * https://github.com/rtyley/spongycastle/blob/spongy-master/core/src/main/java/org/spongycastle/crypto/engines/RC2Engine.java
	 * 
	 * @param mode  cipher mode
	 * @param input string
	 * @param key   cipher key
	 * @return Hash string
	 */
	public static String rc2(Mode mode, String input, String key) {
		org.apache.commons.codec.binary.Base64 base64 = new org.apache.commons.codec.binary.Base64();
		try {
			if (mode == Mode.ENCRYPT) {
				SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8),
						new RC2Engine().getAlgorithmName());
				Cipher cipher = Cipher.getInstance(new RC2Engine().getAlgorithmName());

				cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
				return base64.encodeToString(cipher.doFinal(input.getBytes(StandardCharsets.UTF_8)));
			}
			if (mode == Mode.DECRYPT) {
				SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8),
						new RC2Engine().getAlgorithmName());
				Cipher cipher = Cipher.getInstance(new RC2Engine().getAlgorithmName());
				cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
				return new String(cipher.doFinal(base64.decode(input.getBytes(StandardCharsets.UTF_8))));
			}
		} catch (NoSuchAlgorithmException | BadPaddingException | NoSuchPaddingException | IllegalBlockSizeException
				| InvalidKeyException e) {
			e.printStackTrace();
			return null;
		}
		return null;
	}

	/**
	 * Source code:
	 * https://github.com/rtyley/spongycastle/blob/spongy-master/core/src/main/java/org/spongycastle/crypto/engines/RC4Engine.java
	 * 
	 * @param mode  cipher mode
	 * @param input string
	 * @param key   cipher key
	 * @return Hash string
	 */
	public static String rc4(Mode mode, String input, String key) {
		org.apache.commons.codec.binary.Base64 base64 = new org.apache.commons.codec.binary.Base64();
		try {
			if (mode == Mode.ENCRYPT) {
				SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8),
						new RC4Engine().getAlgorithmName());
				Cipher cipher = Cipher.getInstance(new RC4Engine().getAlgorithmName());

				cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
				return base64.encodeToString(cipher.doFinal(input.getBytes(StandardCharsets.UTF_8)));
			}
			if (mode == Mode.DECRYPT) {
				SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8),
						new RC4Engine().getAlgorithmName());
				Cipher cipher = Cipher.getInstance(new RC4Engine().getAlgorithmName());
				cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
				return new String(cipher.doFinal(base64.decode(input.getBytes(StandardCharsets.UTF_8))));
			}
		} catch (NoSuchAlgorithmException | BadPaddingException | NoSuchPaddingException | IllegalBlockSizeException
				| InvalidKeyException e) {
			e.printStackTrace();
			return null;
		}
		return null;
	}

	/**
	 * Source code:
	 * https://github.com/rtyley/spongycastle/blob/spongy-master/core/src/main/java/org/spongycastle/crypto/engines/RC6Engine.java
	 * See also:
	 * https://github.com/rtyley/spongycastle/blob/spongy-master/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java
	 * Modes:
	 * https://github.com/rtyley/spongycastle/blob/spongy-master/core/src/main/java/org/spongycastle/crypto/modes/CBCBlockCipher.java
	 * Wiki:
	 * https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher_block_chaining_(CBC)
	 * 
	 * @param mode  cipher mode
	 * @param input string
	 * @param key   cipher key
	 * @return Hash string
	 */
	public static String rc6(Mode mode, String input, String key) {
		org.apache.commons.codec.binary.Base64 base64 = new org.apache.commons.codec.binary.Base64();

		try {

			if (mode == Mode.ENCRYPT) {
				BlockCipher engine = new RC6Engine();

				BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(engine));
				cipher.init(true, new KeyParameter(key.getBytes(StandardCharsets.UTF_8)));

				byte[] inputBytes = input.getBytes(StandardCharsets.UTF_8);
				byte[] rv = new byte[cipher.getOutputSize(inputBytes.length)];
				int numOutBytes = cipher.processBytes(inputBytes, 0, inputBytes.length, rv, 0);

				cipher.doFinal(rv, numOutBytes);
				return base64.encodeToString(rv);
			}

			if (mode == Mode.DECRYPT) {
				BlockCipher engine = new RC6Engine();

				BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(engine));
				cipher.init(false, new KeyParameter(key.getBytes(StandardCharsets.UTF_8)));

				byte[] inputBytes = base64.decode(input.getBytes(StandardCharsets.UTF_8));
				byte[] rv = new byte[cipher.getOutputSize(inputBytes.length)];
				int numOutBytes = cipher.processBytes(inputBytes, 0, inputBytes.length, rv, 0);

				cipher.doFinal(rv, numOutBytes);
				return new String(rv, StandardCharsets.UTF_8).replaceAll("\u0000.*", "");
			}

		} catch (DataLengthException | IllegalStateException | InvalidCipherTextException e) {
			e.printStackTrace();
			return null;
		}
		return null;
	}

}