找到了AES加密算法。(当然还有MD5,BASE64什么的http://snowolf.iteye.com/blog/379860这篇文章列举了很多,但是基本都是j2se平台的,android平台不一定支持,但是AES算法Android是自带了包的,从官方的http://developer.android.com/reference/javax/crypto/Cipher.html可以看到。
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AES加密算法是什么?大家可以自己去google,专家级程序员写好包,工程人员会用就行了。
这个例子其实是来自http://www.tutorials-android.com/learn/How_to_encrypt_and_decrypt_strings.rhtml。
src目录主文件:
- package com.qq;
- import java.security.SecureRandom;
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- import javax.crypto.spec.SecretKeySpec;
- import android.app.Activity;
- import android.os.Bundle;
- import android.util.Log;
- public class SimpleCrypto extends Activity {
- 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");
- 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);
- 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);
- byte[] decrypted = cipher.doFinal(encrypted);
- return decrypted;
- }
- public static String toHex(String txt) {
- return toHex(txt.getBytes());
- }
- public static String fromHex(String hex) {
- return new String(toByte(hex));
- }
- 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;
- }
- 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 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));
- }
- /** Called when the activity is first created. */
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- 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 = SimpleCrypto.encrypt(masterPassword,originalText);
- // System.out.println("加密结果为 " + encryptingCode);
- Log.i("加密结果为 ",encryptingCode);
- String decryptingCode = SimpleCrypto.decrypt(masterPassword, encryptingCode);
- System.out.println("解密结果为 " + decryptingCode);
- Log.i("解密结果",decryptingCode);
- } catch (Exception e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- }
布局文件main.xml和配置文件AndroidManifest.xml默认就好了。最后结果在Log里面看,利用adb logcat > d:\1.txt定位到D盘的1.txt文件,然后用记事本打开就,查找”加密结果为“就可以看到了:
运行结果(从log日志中看到的):
I/加密结果为 ( 190): BFB77D8F1E1EE9D5E252926A12659DE8
I/解密结果( 190): 0123456789