Android和.NET通用的AES算法
1.NET源代码:
using System;
using System.Text;
using System.Security.Cryptography;
namespace ConsoleApplicationDemo
{
/// <summary>
/// AES对称加密解密类
/// </summary>
public class AESHelper
{
#region 成员变量
/// <summary>
/// 密钥(32位,不足在后面补0)
/// </summary>
private const string _passwd = "ihlih*0037JOHT*)(PIJY*(()JI^)IO%";
/// <summary>
/// 运算模式
/// </summary>
private static CipherMode _cipherMode = CipherMode.ECB;
/// <summary>
/// 填充模式
/// </summary>
private static PaddingMode _paddingMode = PaddingMode.PKCS7;
/// <summary>
/// 字符串采用的编码
/// </summary>
private static Encoding _encoding = Encoding.UTF8;
#endregion
#region 辅助方法
/// <summary>
/// 获取32byte密钥数据
/// </summary>
/// <param name="password">密码</param>
/// <returns></returns>
private static byte[] GetKeyArray(string password)
{
if (password == null)
{
password = string.Empty;
}
if (password.Length < 32)
{
password = password.PadRight(32, '0');
}
else if (password.Length > 32)
{
password = password.Substring(0, 32);
}
return _encoding.GetBytes(password);
}
/// <summary>
/// 将字符数组转换成字符串
/// </summary>
/// <param name="inputData"></param>
/// <returns></returns>
private static string ConvertByteToString(byte[] inputData)
{
StringBuilder sb = new StringBuilder(inputData.Length * 2);
foreach (var b in inputData)
{
sb.Append(b.ToString("X2"));
}
return sb.ToString();
}
/// <summary>
/// 将字符串转换成字符数组
/// </summary>
/// <param name="inputString"></param>
/// <returns></returns>
private static byte[] ConvertStringToByte(string inputString)
{
if (inputString == null || inputString.Length < 2)
{
throw new ArgumentException();
}
int l = inputString.Length / 2;
byte[] result = new byte[l];
for (int i = 0; i < l; ++i)
{
result[i] = Convert.ToByte(inputString.Substring(2 * i, 2), 16);
}
return result;
}
#endregion
#region 加密
/// <summary>
/// 加密字节数据
/// </summary>
/// <param name="inputData">要加密的字节数据</param>
/// <param name="password">密码</param>
/// <returns></returns>
public static byte[] Encrypt(byte[] inputData, string password)
{
AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
aes.Key = GetKeyArray(password);
aes.Mode = _cipherMode;
aes.Padding = _paddingMode;
ICryptoTransform transform = aes.CreateEncryptor();
byte[] data = transform.TransformFinalBlock(inputData, 0, inputData.Length);
aes.Clear();
return data;
}
/// <summary>
/// 加密字符串(加密为16进制字符串)
/// </summary>
/// <param name="inputString">要加密的字符串</param>
/// <param name="password">密码</param>
/// <returns></returns>
public static string Encrypt(string inputString, string password)
{
byte[] toEncryptArray = _encoding.GetBytes(inputString);
byte[] result = Encrypt(toEncryptArray, password);
return ConvertByteToString(result);
}
/// <summary>
/// 字符串加密(加密为16进制字符串)
/// </summary>
/// <param name="inputString">需要加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string EncryptString(string inputString)
{
return Encrypt(inputString, _passwd);
}
#endregion
#region 解密
/// <summary>
/// 解密字节数组
/// </summary>
/// <param name="inputData">要解密的字节数据</param>
/// <param name="password">密码</param>
/// <returns></returns>
public static byte[] Decrypt(byte[] inputData, string password)
{
AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
aes.Key = GetKeyArray(password);
aes.Mode = _cipherMode;
aes.Padding = _paddingMode;
ICryptoTransform transform = aes.CreateDecryptor();
byte[] data = null;
try
{
data = transform.TransformFinalBlock(inputData, 0, inputData.Length);
}
catch
{
return null;
}
aes.Clear();
return data;
}
/// <summary>
/// 解密16进制的字符串为字符串
/// </summary>
/// <param name="inputString">要解密的字符串</param>
/// <param name="password">密码</param>
/// <returns>字符串</returns>
public static string Decrypt(string inputString, string password)
{
byte[] toDecryptArray = ConvertStringToByte(inputString);
string decryptString = _encoding.GetString(Decrypt(toDecryptArray, password));
return decryptString;
}
/// <summary>
/// 解密16进制的字符串为字符串
/// </summary>
/// <param name="inputString">需要解密的字符串</param>
/// <returns>解密后的字符串</returns>
public static string DecryptString(string inputString)
{
return Decrypt(inputString, _passwd);
}
#endregion
}
}
2.Android代码:
package com.google.test;
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);
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;
}
}
另:要支持AES/ECB/ZeroBytePadding(对应.net的PaddingMode.Zeros)，需引入bcprov .jar!
