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@armanso
Last active March 26, 2025 05:39
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AES encryption/decryption in crypto-js way, use KDF for generating IV and Key, use CBC with PKCS7Padding for Cipher
import com.sun.jersey.core.util.Base64;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Random;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AES {
/**
*
* Conforming with CryptoJS AES method
* **** YOU NEED TO ADD "JCE policy" to have ability to DEC/ENC 256 key-lenght with AES Cipher ****
*
*/
// Prevent facing error when using "PKCS7Padding" in Cipher
// add Bouncycastle provider [link=http://www.bouncycastle.org/latest_releases.html]
static {
java.security.Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
}
static int KEY_SIZE = 256;
static int IV_SIZE = 128;
static String HASH_CIPHER = "AES/CBC/PKCS7Padding";
static String AES = "AES";
static String CHARSET_TYPE = "UTF-8";
static String KDF_DIGEST = "MD5";
// Seriously crypto-js, what's wrong with you?
static String APPEND = "Salted__";
/**
* Encrypt
* @param password passphrase
* @param plainText plain string
*/
public static String encrypt(String password,String plainText) throws UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
byte[] saltBytes = generateSalt(8);
byte[] key = new byte[KEY_SIZE/8];
byte[] iv = new byte[IV_SIZE/8];
EvpKDF(password.getBytes(CHARSET_TYPE), KEY_SIZE, IV_SIZE, saltBytes, key, iv);
SecretKey keyS = new SecretKeySpec(key, AES);
Cipher cipher = Cipher.getInstance(HASH_CIPHER);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.ENCRYPT_MODE, keyS, ivSpec);
byte[] cipherText = cipher.doFinal(plainText.getBytes(CHARSET_TYPE));
// Thanks kientux for this: https://gist.github.com/kientux/bb48259c6f2133e628ad
// Create CryptoJS-like encrypted !
byte[] sBytes = APPEND.getBytes(CHARSET_TYPE);
byte[] b = new byte[sBytes.length + saltBytes.length + cipherText.length];
System.arraycopy(sBytes, 0, b, 0, sBytes.length);
System.arraycopy(saltBytes, 0, b, sBytes.length, saltBytes.length);
System.arraycopy(cipherText, 0, b, sBytes.length + saltBytes.length, cipherText.length);
byte[] bEncode = Base64.encode(b);
return new String(bEncode);
}
/**
* Decrypt
* Thanks Artjom B. for this: http://stackoverflow.com/a/29152379/4405051
* @param password passphrase
* @param cipherText encrypted string
*/
public static String decrypt(String password,String cipherText) throws UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
byte[] ctBytes = Base64.decode(cipherText.getBytes(CHARSET_TYPE));
byte[] saltBytes = Arrays.copyOfRange(ctBytes, 8, 16);
byte[] ciphertextBytes = Arrays.copyOfRange(ctBytes, 16, ctBytes.length);
byte[] key = new byte[KEY_SIZE/8];
byte[] iv = new byte[IV_SIZE/8];
EvpKDF(password.getBytes(CHARSET_TYPE), KEY_SIZE, IV_SIZE, saltBytes, key, iv);
Cipher cipher = Cipher.getInstance(HASH_CIPHER);
SecretKey keyS = new SecretKeySpec(key, AES);
cipher.init(Cipher.DECRYPT_MODE, keyS, new IvParameterSpec(iv));
byte[] plainText = cipher.doFinal(ciphertextBytes);
return new String(plainText);
}
private static byte[] EvpKDF(byte[] password, int keySize, int ivSize, byte[] salt, byte[] resultKey, byte[] resultIv) throws NoSuchAlgorithmException {
return EvpKDF(password, keySize, ivSize, salt, 1, KDF_DIGEST, resultKey, resultIv);
}
private static byte[] EvpKDF(byte[] password, int keySize, int ivSize, byte[] salt, int iterations, String hashAlgorithm, byte[] resultKey, byte[] resultIv) throws NoSuchAlgorithmException {
keySize = keySize / 32;
ivSize = ivSize / 32;
int targetKeySize = keySize + ivSize;
byte[] derivedBytes = new byte[targetKeySize * 4];
int numberOfDerivedWords = 0;
byte[] block = null;
MessageDigest hasher = MessageDigest.getInstance(hashAlgorithm);
while (numberOfDerivedWords < targetKeySize) {
if (block != null) {
hasher.update(block);
}
hasher.update(password);
block = hasher.digest(salt);
hasher.reset();
// Iterations
for (int i = 1; i < iterations; i++) {
block = hasher.digest(block);
hasher.reset();
}
System.arraycopy(block, 0, derivedBytes, numberOfDerivedWords * 4,
Math.min(block.length, (targetKeySize - numberOfDerivedWords) * 4));
numberOfDerivedWords += block.length/4;
}
System.arraycopy(derivedBytes, 0, resultKey, 0, keySize * 4);
System.arraycopy(derivedBytes, keySize * 4, resultIv, 0, ivSize * 4);
return derivedBytes; // key + iv
}
private static byte[] generateSalt(int length) {
Random r = new SecureRandom();
byte[] salt = new byte[length];
r.nextBytes(salt);
return salt;
}
}
@thackerronak
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thackerronak commented Nov 27, 2017

Working fine. Thanks

@thackerronak
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need js code for same

@copancn
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copancn commented Mar 26, 2025

Thank you for sharing,great job.

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