c#加密对称JAVADES/RSA/成功解密成功。

c#加密对称java DES

找过好多资料和下载过好多文件，对称加密就是解不出来，JAVA和.NET的系统类库里都有封装DES对称加密的实现方式却各不相同，甚至有时会让自己难以解决其中的问题，比如JAVA加密后的结果在.NET中解密不出来等，最近项目有跨JAVA和.NET的加解密，经过不断的调试，终于让它们可以互相加密解密了。

过程就不说了

调试记录：

方法一：使用java加密和c#加密对比，老是差几位对不上，JAVA无法解析

秘钥：DESTEST0

示例一：

秘钥：DESTEST0

字符串：123456

【JAVA解密】
ClVgIaLATSY=

【C#解密】：
ClVgIaLATSY=

【结果】：一致

两者解密结果正确

你也为这样就结束了吗? no no no，小伙子你还太年轻

示例二：
内容
{"sex":"男","username":"张三"}
【JAVA解密】
postStr:{"sex":"男","username":"张三"}
dtNza+iraz7dWIbZRskINjrQ7gj0OKstHHjwmlp60e0cioA3VGhJfw==

【C#解密】：
dtNza+iraz7HqdqNjYkMTpGo9aRG7VzETlIgBbXi5A33d+LLvFSqBQ==

【结果】：不一致

我的娘呀,找找找原因

找了半天原因：终于找到原因：

  // java 默认的是ECB模式，PKCS5padding；c#默认的CBC模式，PKCS7padding 所以这里我们默认使用ECB方式

所以你一直按各种示例，各种调试就是玩，解密不一样

经过不断的尝试的JAVA人员查看，终于调试通，做个备注和分享。

 成功的DES加解密

一、调试成功，上代码

C#调试成功代码

public class DESHelper
   {
 
       /// <summary>
       /// DES加密算法
       /// </summary>
       /// <param name="encryptString">要加密的字符串</param>
       /// <param name="sKey">加密码Key</param>
       /// <returns>正确返回加密后的结果，错误返回源字符串</returns>
       public static string ToDESEncrypt(string encryptString, string sKey)
       {
           try
           {
 
               byte[] keyBytes = Encoding.UTF8.GetBytes(sKey);
               byte[] keyIV = keyBytes;
               byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
 
               DESCryptoServiceProvider desProvider = new DESCryptoServiceProvider();
 
               // java 默认的是ECB模式，PKCS5padding；c#默认的CBC模式，PKCS7padding 所以这里我们默认使用ECB方式
               desProvider.Mode = CipherMode.ECB;
               MemoryStream memStream = new MemoryStream();
               CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateEncryptor(keyBytes, keyIV), CryptoStreamMode.Write);
 
               crypStream.Write(inputByteArray, 0, inputByteArray.Length);
               crypStream.FlushFinalBlock();
               return Convert.ToBase64String(memStream.ToArray());
 
           }
           catch
           {
               return encryptString;
           }
       }
 
 
       /// <summary>
       /// DES解密算法
       /// </summary>
       /// <param name="decryptString">要解密的字符串</param>
       /// <param name="sKey">加密Key</param>
       /// <returns>正确返回加密后的结果，错误返回源字符串</returns>
       public static string ToDESDecrypt(string decryptString, string sKey)
       {
           byte[] keyBytes = Encoding.UTF8.GetBytes(sKey);
           byte[] keyIV = keyBytes;
           byte[] inputByteArray = Convert.FromBase64String(decryptString);
 
           DESCryptoServiceProvider desProvider = new DESCryptoServiceProvider();
 
           // java 默认的是ECB模式，PKCS5padding；c#默认的CBC模式，PKCS7padding 所以这里我们默认使用ECB方式
           desProvider.Mode = CipherMode.ECB;
           MemoryStream memStream = new MemoryStream();
           CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateDecryptor(keyBytes, keyIV), CryptoStreamMode.Write);
 
           crypStream.Write(inputByteArray, 0, inputByteArray.Length);
           crypStream.FlushFinalBlock();
           return Encoding.Default.GetString(memStream.ToArray());
 
       }
   }

JAVA

public class DESHelper {
 
    private byte[] desKey;
 
    public DES(String desKey) {
        this.desKey = desKey.getBytes();
    }
 
    public byte[] desEncrypt(byte[] plainText) throws Exception {
        SecureRandom sr = new SecureRandom();
        byte rawKeyData[] = desKey;
        DESKeySpec dks = new DESKeySpec(rawKeyData);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey key = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.ENCRYPT_MODE, key, sr);
        byte data[] = plainText;
        byte encryptedData[] = cipher.doFinal(data);
        return encryptedData;
    }
 
    public byte[] desDecrypt(byte[] encryptText) throws Exception {
        SecureRandom sr = new SecureRandom();
        byte rawKeyData[] = desKey;
        DESKeySpec dks = new DESKeySpec(rawKeyData);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey key = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.DECRYPT_MODE, key, sr);
        byte encryptedData[] = encryptText;
        byte decryptedData[] = cipher.doFinal(encryptedData);
        return decryptedData;
    }
 
    public String encrypt(String input) throws Exception {
        return base64Encode(desEncrypt(input.getBytes()));
    }
 
    public String decrypt(String input) throws Exception {
        byte[] result = base64Decode(input);
        return new String(desDecrypt(result));
    }
 
    public static String base64Encode(byte[] s) {
        if (s == null)
            return null;
        BASE64Encoder b = new sun.misc.BASE64Encoder();
        return b.encode(s);
    }
 
    public static byte[] base64Decode(String s) throws IOException {
        if (s == null)
            return null;
        BASE64Decoder decoder = new BASE64Decoder();
        byte[] b = decoder.decodeBuffer(s);
        return b;
    }
     
}

二、还有一种是C#编码格式：GBK和UTF-8 两种，可惜这个解决老对不上，也有可以是对JAVA的加密方式和我们要求的不一样。

       //加密
            public static string DESEncode(string encryptString, string encryptKey)
        {
            if (encryptKey.Length != 8)
            {
                return null;
            }
            DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
            byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey);
            byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
            //byte[] rgbKey = Encoding.GetEncoding("GBK").GetBytes(encryptKey);
            //byte[] inputByteArray = Encoding.GetEncoding("GBK").GetBytes(encryptString);

            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, new byte[8]), CryptoStreamMode.Write);
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();
            return Convert.ToBase64String(mStream.ToArray());
        }
　　　　//解密
        public static string DESDecode(string decryptString, string decryptKey)
        {
            if (decryptKey.Length != 8)
            {
                return null;
            }
            byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
            //byte[] rgbKey = Encoding.GetEncoding("GBK").GetBytes(decryptKey);
            byte[] inputByteArray = Convert.FromBase64String(decryptString);

            DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, new byte[8]), CryptoStreamMode.Write);
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();
            return Encoding.GetEncoding("utf-8").GetString(mStream.ToArray());
        }

JAVA

三、工具：还有各种加密

分别用C#、Java实现的RSA和DES加解密算法等。

亲试通过，放心使用……