Android AES Decrypt aesDecode(String seed, String encrypted)

Description

aes Decode

Declaration

public static String aesDecode(String seed, String encrypted)
            throws Exception 

Method Source Code

//package com.java2s;

import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

public class Main {
    public static String aesDecode(String seed, String encrypted)
            throws Exception {
        byte[] rawKey = getRawKey(seed.getBytes());
        byte[] enc = toByte(encrypted);
        byte[] result = decrypt(rawKey, enc);
        return new String(result);
    }/*from www. j  av a  2s .c o m*/

    private static byte[] getRawKey(byte[] seed) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
        sr.setSeed(seed);
        kgen.init(128, sr); // 192 and 256 bits may not be available
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();
        return raw;
    }

    public static byte[] toByte(String hexString) {
        int len = hexString.length() / 2;
        byte[] result = new byte[len];
        for (int i = 0; i < len; i++)
            result[i] = Integer.valueOf(
                    hexString.substring(2 * i, 2 * i + 2), 16).byteValue();
        return result;
    }

    private static byte[] decrypt(byte[] raw, byte[] encrypted)
            throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] decrypted = cipher.doFinal(encrypted);
        return decrypted;
    }
}

Related

1. decryptBytes(byte[] data, byte[] key)
2. decryptHex(String content, String key)
3. decryptHex(String content, String username, String password)
4. decryptNumberWithAES(String encrypted)
5. decryptUrlDecode(String dataPassword, String encrypted)
6. decrypt(byte[] raw, byte[] encrypted)
7. decrypt(Context context, String encrypted)
8. decrypt(Context context, String encrypted)
9. decode(String seed, String encrypted)