1、AES加密工具类
java不支持PKCS7Padding,只支持PKCS5Padding。我们知道加密算法由算法+模式+填充组成,下一篇介绍iOS和Android通用的AES加密,本篇文章使用PKCS5Padding加密方式。
package com.example.aesdemo; import java.io.UnsupportedEncodingException; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; ///** AES对称加密解密类 **/ public class AESHelper { // /** 算法/模式/填充 **/ private static final String CipherMode = "AES/ECB/PKCS5Padding"; ///** 创建密钥 **/ private static SecretKeySpec createKey(String password) { byte[] data = null; if (password == null) { password = ""; } StringBuffer sb = new StringBuffer(32); sb.append(password); while (sb.length() <32) { sb.append("0"); } if (sb.length() > 32) { sb.setLength(32); } try { data = sb.toString().getBytes("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return new SecretKeySpec(data, "AES"); } // /** 加密字节数据 **/ public static byte[] encrypt(byte[] content, String password) { try { SecretKeySpec key = createKey(password); System.out.println(key); Cipher cipher = Cipher.getInstance(CipherMode); cipher.init(Cipher.ENCRYPT_MODE, key); byte[] result = cipher.doFinal(content); return result; } catch (Exception e) { e.printStackTrace(); } return null; } ///** 加密(结果为16进制字符串) **/ public static String encrypt(String content, String password) { byte[] data = null; try { data = content.getBytes("UTF-8"); } catch (Exception e) { e.printStackTrace(); } data = encrypt(data, password); String result = byte2hex(data); return result; } // /** 解密字节数组 **/ public static byte[] decrypt(byte[] content, String password) { try { SecretKeySpec key = createKey(password); Cipher cipher = Cipher.getInstance(CipherMode); cipher.init(Cipher.DECRYPT_MODE, key); byte[] result = cipher.doFinal(content); return result; } catch (Exception e) { e.printStackTrace(); } return null; } ///** 解密16进制的字符串为字符串 **/ public static String decrypt(String content, String password) { byte[] data = null; try { data = hex2byte(content); } catch (Exception e) { e.printStackTrace(); } data = decrypt(data, password); if (data == null) return null; String result = null; try { result = new String(data, "UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return result; } // /** 字节数组转成16进制字符串 **/ public static String byte2hex(byte[] b) { // 一个字节的数, StringBuffer sb = new StringBuffer(b.length * 2); String tmp = ""; for (int n = 0; n
2、使用
新建Android工程
package com.example.aesdemo; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.util.Log; public class MainActivity extends Activity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); String masterPassword = "a"; String originalText = "于"; try { String encryptingCode = AESHelper.encrypt(originalText,masterPassword); // System.out.println("加密结果为 " + encryptingCode); Log.i("加密结果为 ",encryptingCode); String decryptingCode = AESHelper.decrypt(encryptingCode,masterPassword); // 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(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } }
3、打印结果
09-19 10:41:05.467: I/加密结果为(707): E55C24701F6380478E1940ADDFD08D22 09-19 10:41:05.467: I/解密结果(707): 于