Android AES Encrypt encrypt(String seed, String clearText)

Description

encrypt

Declaration

public static String encrypt(String seed, String clearText) 

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.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class Main {

    public static String encrypt(String seed, String clearText) {
        byte[] result = null;
        try {//ww w  .  j a va2s .c  om
            byte[] rawkey = getRawKey(seed.getBytes());
            result = encrypt(rawkey, clearText.getBytes());
        } catch (Exception e) {
            e.printStackTrace();
        }
        String content = toHex(result);
        return content;

    }

    private static byte[] encrypt(byte[] raw, byte[] clear)
            throws Exception {
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        //        Cipher cipher = Cipher.getInstance("AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(
                new byte[cipher.getBlockSize()]));
        byte[] encrypted = cipher.doFinal(clear);
        return encrypted;
    }

    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);
        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) {
        final String HEX = "0123456789ABCDEF";
        sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
    }
}

Related

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