Android Password Descrypt decrypt(String password, String encryptedData)

Description

decrypt

License

Open Source License

Declaration

public static String decrypt(String password, String encryptedData)
            throws Exception 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;

public class Main {
    private static final String CIPHER_ALGORITHM = "AES";
    private static final String RANDOM_GENERATOR_ALGORITHM = "SHA1PRNG";
    private static final int RANDOM_KEY_SIZE = 128;

    public static String decrypt(String password, String encryptedData)
            throws Exception {
        byte[] secretKey = generateKey(password.getBytes());
        SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey,
                CIPHER_ALGORITHM);/*from  w  ww  .  ja v  a 2  s  . c om*/
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
        byte[] encrypted = Base64.decode(encryptedData, Base64.DEFAULT);
        byte[] decrypted = cipher.doFinal(encrypted);
        return new String(decrypted);
    }

    public static byte[] generateKey(byte[] seed) throws Exception {
        KeyGenerator keyGenerator = KeyGenerator
                .getInstance(CIPHER_ALGORITHM);
        SecureRandom secureRandom = SecureRandom
                .getInstance(RANDOM_GENERATOR_ALGORITHM);
        secureRandom.setSeed(seed);
        keyGenerator.init(RANDOM_KEY_SIZE, secureRandom);
        SecretKey secretKey = keyGenerator.generateKey();
        return secretKey.getEncoded();
    }
}

Related

1. decryptionKey(String password)
2. decryptionKey(String password)