Java AES encryptDecrypt(int mode, String data, String key, String salt, String iv)

Description

Encrypts and decrypts a string.

License

Open Source License

Parameter

Parameter	Description
mode	integer that determines whether to encrypt or decrypt
data	data to encrypt/decrypt
key	encryption/decryption key
salt	random salt
iv	random initialization vector

Exception

Parameter	Description

Return

encrypted/decrypted string

Declaration

public static String encryptDecrypt(int mode, String data, String key, String salt, String iv)
        throws Exception 

Method Source Code

//package com.java2s;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.nio.charset.StandardCharsets;
import java.security.NoSuchAlgorithmException;

import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

public class Main {
    public final static int DECRYPT_MODE = 2;
    private final static int ITERATIONS = 10000;
    private final static int KEY_LENGTH = 128;
    private final static String SECRET_KEY_FACTORY_ALGORITHM = "PBKDF2WithHmacSHA1";
    private final static String SECRET_KEY_ALGORITHM = "AES";
    private final static String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding";

    /**//from  ww  w. j av a2  s .  co  m
     * Encrypts and decrypts a string.
     *
     * @param mode integer that determines whether to encrypt or decrypt
     * @param data data to encrypt/decrypt
     * @param key  encryption/decryption key
     * @param salt random salt
     * @param iv   random initialization vector
     * @return encrypted/decrypted string
     * @throws java.security.spec.InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException
     */
    public static String encryptDecrypt(int mode, String data, String key, String salt, String iv)
            throws Exception {
        KeySpec pbeKeySpec = new PBEKeySpec(key.toCharArray(), DatatypeConverter.parseBase64Binary(salt),
                ITERATIONS, KEY_LENGTH);
        SecretKey secretKey = getSecretKey(pbeKeySpec);
        Cipher cipher = getCipher();
        cipher.init(mode, secretKey, new IvParameterSpec(DatatypeConverter.parseBase64Binary(iv)));
        if (mode == DECRYPT_MODE) {
            return new String(cipher.doFinal(DatatypeConverter.parseBase64Binary(data)), StandardCharsets.UTF_8);
        } else {
            return DatatypeConverter.printBase64Binary(cipher.doFinal(data.getBytes(StandardCharsets.UTF_8)));
        }
    }

    /**
     * Generates SecretKey.
     *
     * @param pbeKeySpec password based encryption key spec
     * @return SecretKey
     * @throws java.security.NoSuchAlgorithmException, InvalidKeySpecException
     */
    private static SecretKey getSecretKey(KeySpec pbeKeySpec)
            throws NoSuchAlgorithmException, InvalidKeySpecException {
        SecretKey tmpKey = getSecretKeyFactory().generateSecret(pbeKeySpec);
        return new SecretKeySpec(tmpKey.getEncoded(), SECRET_KEY_ALGORITHM);
    }

    /**
     * Generates a cipher.
     *
     * @return Cipher
     * @throws javax.crypto.NoSuchPaddingException, NoSuchAlgorithmException
     */
    private static Cipher getCipher() throws NoSuchPaddingException, NoSuchAlgorithmException {
        return Cipher.getInstance(CIPHER_ALGORITHM);
    }

    /**
     * Generates SecretKeyFactory.
     *
     * @return SecretKeyFactory
     * @throws java.security.NoSuchAlgorithmException
     */
    private static SecretKeyFactory getSecretKeyFactory() throws NoSuchAlgorithmException {
        return SecretKeyFactory.getInstance(SECRET_KEY_FACTORY_ALGORITHM);
    }
}

Related

1. aesStoreKeyToFile(Key secretKey, String path)
2. createSessionKey()
3. decrypt(String encryptedText, String key)
4. decrypt_aes(String key, String initVector, String encrypted)
5. encryptAes(String value)
6. getAesKey(String key)