LESS TALK, MORE CODE: Encryption

Monday

Triple DES (3DES) with CBC mode algorithm in java

import java.security.Key;

import java.util.Arrays;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Hex;

public static void main(String[] args) {

String yourOwnKey = "ASDFGHJKLZXCVBNMQWERTYUI", originalText = "Give your text to encrypt.";

decrypt(encrypt(originalText, yourOwnKey), yourOwnKey);

}

public static String encrypt(String originalText, String yourOwnKey) {

String encryptedText = null;

byte[] bytes = null;

try {

bytes = originalText.getBytes();

bytes = Arrays.copyOf(bytes, ((bytes.length + 7) / 8) * 8);

Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");

SecretKey key = new SecretKeySpec(yourOwnKey.getBytes(), "DESede");

IvParameterSpec iv = new IvParameterSpec(new byte[8]);

cipher.init(Cipher.ENCRYPT_MODE, (Key) key, iv);

byte[] encryptByte = cipher.doFinal(bytes);

encryptedText = new String(Hex.encodeHex(encryptByte));

System.out.println("originalText: " +originalText+ " --> encryptedText: " + encryptedText);

} catch (Exception e) {

//throw || log

}

return encryptedText;

}

public static String decrypt(String encryptedTxt, String yourOwnKey) {

String decryptedText = null;

byte[] bytes = null;

try {

bytes = Hex.decodeHex(encryptedTxt.toCharArray());

Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");

SecretKey key = new SecretKeySpec(yourOwnKey.getBytes(), "DESede");

IvParameterSpec iv = new IvParameterSpec(new byte[8]);

cipher.init(Cipher.DECRYPT_MODE, (Key) key, iv);

byte[] decryptByte = cipher.doFinal(bytes);

decryptedText = new String(decryptByte);

if (decryptedText.indexOf((char) 0) > 0)

decryptedText = decryptedText.substring(0, decryptedText.indexOf((char) 0));

System.out.println("encryptedTxt: " +encryptedTxt+ " --> decryptedText: " + decryptedText);

} catch (Exception e) {

//throw || log

}

return decryptedText;

}

Thursday

Encrypt/Decrypt string with DES algorithm in java

public static void main(String[] args) throws Exception {

byte[] message = "Give your text to encrypt.".getBytes();

byte[] keyValue = "YourOwnKey".getBytes();

Cipher cipher = Cipher.getInstance("DES");

DESKeySpec dks = new DESKeySpec(keyValue);

SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");

SecretKey desKey = skf.generateSecret(dks);

cipher.init(Cipher.ENCRYPT_MODE, desKey);

byte[] textEncrypted = cipher.doFinal(message);

String encrypted = DatatypeConverter.printBase64Binary(textEncrypted);

System.out.println("Text Encrypted : " + encrypted);

cipher.init(Cipher.DECRYPT_MODE, desKey);

byte[] texDecrypted = cipher.doFinal(textEncrypted);

System.out.println("Text Decryted : " + new String(texDecrypted) );

}