Android和.NET通用的AES算法

原文引自 http://www.cnblogs.com/ahui/archive/2011/04/22/2025045.html

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!