AES android基本使用

import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.ImageView;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 MainActivity extends AppCompatActivity {    private ImageView mIv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mIv = (ImageView) findViewById(R.id.iv);    }    public void go(View view) {        String masterPassword = "a";        String originalText = "0123456789";        byte[] text = new byte[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};        byte[] password = new byte[]{'a'};        try {            String encryptingCode = encrypt(masterPassword, originalText);//          System.out.println("加密结果为 " + encryptingCode);            Log.i("加密结果为 ", encryptingCode);            String decryptingCode = decrypt(masterPassword, encryptingCode);            Log.i("解密结果", decryptingCode);        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    public static String encrypt(String seed, String cleartext) throws Exception {        byte[] rawKey = getRawKey(seed.getBytes());        byte[] result = encrypt(rawKey, cleartext.getBytes());        return toHex(result);    }    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);    }    private static byte[] getRawKey(byte[] seed) throws Exception {        KeyGenerator kgen = KeyGenerator.getInstance("AES");        SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");        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;    }    private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");        Cipher cipher = Cipher.getInstance("AES");        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));        byte[] encrypted = cipher.doFinal(clear);        return encrypted;    }    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, new IvParameterSpec(new byte[cipher.getBlockSize()]));        byte[] decrypted = cipher.doFinal(encrypted);        return decrypted;    }    private static String toHex(String txt) {        return toHex(txt.getBytes());    }    private static String fromHex(String hex) {        return new String(toByte(hex));    }    private 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 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 final static String HEX = "0123456789ABCDEF";    private static void appendHex(StringBuffer sb, byte b) {        sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));    }}