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。
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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 < b.length; n++) { // 整数转成十六进制表示 tmp = (java.lang.Integer.toHexString(b[n] & 0XFF)); if (tmp.length() == 1) { sb.append("0"); } sb.append(tmp); } return sb.toString().toUpperCase(); // 转成大写 } // /** 将hex字符串转换成字节数组 **/ private static byte[] hex2byte(String inputString) { if (inputString == null || inputString.length() < 2) { return new byte[0]; } inputString = inputString.toLowerCase(); int l = inputString.length() / 2; byte[] result = new byte[l]; for (int i = 0; i < l; ++i) { String tmp = inputString.substring(2 * i, 2 * i + 2); result[i] = (byte) (Integer.parseInt(tmp, 16) & 0xFF); } return result; }} |
2、使用
新建Android工程
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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
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09-19 10:41:05.467: I/加密结果为(707): E55C24701F6380478E1940ADDFD08D2209-19 10:41:05.467: I/解密结果(707): 于 |
