Android AES Encrypt encrypt(String key, String src)

Description

encrypt

Declaration

public static String encrypt(String key, String src) 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;
import android.os.Build;

public class Main {
    private final static String HEX = "0123456789ABCDEF";

    public static String encrypt(String key, String src) throws Exception {
        byte[] rawKey = getRawKey(key.getBytes());
        byte[] result = encrypt(rawKey, src.getBytes());
        return toHex(result);
    }/*from   w ww .jav a 2s  . c o  m*/

    private static byte[] encrypt(byte[] key, byte[] src) throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(src);
        return encrypted;
    }

    private static byte[] getRawKey(byte[] seed) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        SecureRandom sr = null;
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
        } else if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
        } else {
            sr = SecureRandom.getInstance("SHA1PRNG");
        }
        sr.setSeed(seed);
        kgen.init(256, sr); //256 bits or 128 bits,192bits  
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();
        return raw;
    }

    public static String toHex(String txt) {
        return toHex(txt.getBytes());
    }

    public static String toHex(byte[] buf) {
        if (buf == null)
            return "";
        StringBuffer result = new StringBuffer(2 * buf.length);
        for (int i = 0; i < buf.length; i++) {
            appendHex(result, buf[i]);
        }
        return result.toString();
    }

    private static void appendHex(StringBuffer sb, byte b) {
        sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
    }
}

Related

1. encrypt(String content, String password)
2. encrypt(String content, String password)
3. encrypt(String data)
4. encrypt(String dataPassword, String cleartext)
5. encrypt(String key, String src)
6. encrypt(String seed, String clearText)
7. encrypt(String seed, String clearText)
8. encrypt(String seed, String cleartext)
9. encrypt(String src)