Android AES Decrypt decrypt(String seed, String encrypted)

Description

decrypt

Declaration

public static String decrypt(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 decrypt(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   w w  w . j  a va2  s .  c  o  m

    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;
    }

    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;
    }
}

Related

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2. decrypt(String dataPassword, String encrypted)
3. decrypt(String encrypted)
4. decrypt(String key, String encrypted)
5. decrypt(String key, String src)
6. decrypt(String seed, String encrypted)
7. decrypt(String seed, String encrypted)
8. decrypt(String src)
9. decrypt(String src)