C#做的一个加密解密的类

    技术2022-05-11  17

              大家要有兴趣,可以一起来讨论一下 WebService数据交互安全问题,以下的这个代码,可以用于Dotnet环境下的任何托管方式的应用程序,在实际应用中有两个实例。其中,有一个挂在Internet上的,URL:http://www.tttsss.com/webservice/THRDataService.asmx , 有兴趣的可以看看其中的Soap信息。当然,要看里面的加密解密过程,就没办法了!否则,我呀太没面子了,是吧!

              前两年写的东西,现在整理一下发出来!以前公司需要做WebService,并且对WebService的SoapHeader进行加密,所以就写了这么个东东!使用这个类,需要密钥管理!为了保证数据的安全性往往要对数据进行加密,但是加密的缺点之一,就是影响程序的运行效率,所以,当时我的思路是只对用户的登录信息(用户名,密码)进行加密!数据用明文传输,用户信息验证没有通过的情况下, 不进行数据传输。

              实际在网络通讯中,使用密钥匙的方式并非无懈可击,如果黑客可以捕捉到用密钥加密的,用户验证信息,然后,做个模拟请求,向提供WebService的服务器发请求,还是可以获得请求数据!所以,我又使用了IP或者域名绑定的方式!毕竟,WebService不是直接对最终用户提供的!所以,加上以上这些手段后,就算有不良企图者想通过非法方式获得WebService提供的服务,就再费点劲吧!            

              还有一点安全建议,就是定期的更换密钥,在这个例子中,我用的是对称加密,加密方和解密方的密钥一致!定期的更换密钥可以让安全性提高一大截!

              大家要有更好的方法,或者建议,可以留言讨论一下!共同提高!

    代码如下:

    using System;using System.Security.Cryptography ;using System.Text; using System.IO;

    namespace SEDO{  /// <summary> /// SEDO 的摘要说明。 /// SEDO 实现的是用一个封装了4种对称加密方法(Des,Rc2,Rijndael,TripleDes)的组件 ///  /// 注意事项: /// 1:TripleDes和Rijndael加密/解密对象使用16或者24位byte的Key /// 2:Rijndael只能使用16位的初始化向量IV /// 3:Des和Rc2均使用8位Byte的Key和IV /// 4:对需要加密/解密的数据流采用何种方法进行编码/解码,由调用组件的用户自己决定 /// 5:密钥和初始化向量IV由使用者自己定义 /// 程序员: 王海波 2003-05-19 hwnanghb@21cn.com /// </summary>  //定义加密类型的枚举 public enum EncryptionAlgorithm {Des = 1, Rc2, Rijndael, TripleDes};

     //定义加密类 internal class EncryptTransformer {  private EncryptionAlgorithm algorithmID;  private byte[] initVec;  private byte[] encKey;

      internal EncryptTransformer(EncryptionAlgorithm algId)  {   //Save the algorithm being used.   algorithmID = algId;  }

      internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)  {   //当数据密钥Key或者初始化向量IV为空的时候,将使用加密对象自动产生的密钥Key或者初始化向量IV   switch (algorithmID)   {    case EncryptionAlgorithm.Des:    {     DES des = new DESCryptoServiceProvider();     des.Mode = CipherMode.CBC;

         // See if a key was provided     if (null == bytesKey)     {      encKey = des.Key;     }     else     {      des.Key = bytesKey;      encKey = des.Key;     }     // See if the client provided an initialization vector     if (null == initVec)     { // Have the algorithm create one      initVec = des.IV;     }     else     { //No, give it to the algorithm      des.IV = initVec;     }     return des.CreateEncryptor();    }    case EncryptionAlgorithm.TripleDes:    {     TripleDES des3 = new TripleDESCryptoServiceProvider();     des3.Mode = CipherMode.CBC;     // See if a key was provided     if (null == bytesKey)     {      encKey = des3.Key;     }     else     {      des3.Key = bytesKey;      encKey = des3.Key;     }     // See if the client provided an IV     if (null == initVec)     { //Yes, have the alg create one      initVec = des3.IV;     }     else     { //No, give it to the alg.      des3.IV = initVec;     }     return des3.CreateEncryptor();    }    case EncryptionAlgorithm.Rc2:    {     RC2 rc2 = new RC2CryptoServiceProvider();     rc2.Mode = CipherMode.CBC;     // Test to see if a key was provided     if (null == bytesKey)     {      encKey = rc2.Key;     }     else     {      rc2.Key = bytesKey;      encKey = rc2.Key;     }     // See if the client provided an IV     if (null == initVec)     { //Yes, have the alg create one      initVec = rc2.IV;     }     else     { //No, give it to the alg.      rc2.IV = initVec;     }     return rc2.CreateEncryptor();    }    case EncryptionAlgorithm.Rijndael:    {     Rijndael rijndael = new RijndaelManaged();     rijndael.Mode = CipherMode.CBC;     // Test to see if a key was provided     if(null == bytesKey)     {      encKey = rijndael.Key;     }     else     {      rijndael.Key = bytesKey;      encKey = rijndael.Key;     }     // See if the client provided an IV     if(null == initVec)     { //Yes, have the alg create one      initVec = rijndael.IV;     }     else     { //No, give it to the alg.      rijndael.IV = initVec;     }     return rijndael.CreateEncryptor();    }     default:    {     throw new CryptographicException("Algorithm ID '" +       algorithmID +       "' not supported.");    }   }  }

      //加密的偏移向量  internal byte[] IV  {   get{return initVec;}   set{initVec = value;}  }  //加密的密钥  internal byte[] Key  {   get{return encKey;}   set{encKey = value;}  }

     }

     //定义解密类 internal class DecryptTransformer {  private EncryptionAlgorithm algorithmID;  private byte[] initVec;  private byte[] encKey;

      internal DecryptTransformer(EncryptionAlgorithm deCryptId)  {   algorithmID = deCryptId;  }

      //加密的偏移向量  internal byte[] IV  {   get{return initVec;}   set{initVec = value;}  }    //加密的密钥  internal byte[] Key  {   get{return encKey;}   set{encKey = value;}  }

      internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)  {   //当数据密钥Key或者初始化向量IV为空的时候,将使用加密对象自动产生的密钥Key或者初始化向量IV   switch (algorithmID)   {    case EncryptionAlgorithm.Des:    {     DES des = new DESCryptoServiceProvider();     des.Mode = CipherMode.CBC;     des.Key = bytesKey;     des.IV = initVec;     return des.CreateDecryptor();    }    case EncryptionAlgorithm.TripleDes:    {     TripleDES des3 = new TripleDESCryptoServiceProvider();     des3.Mode = CipherMode.CBC;     return des3.CreateDecryptor(bytesKey, initVec);    }    case EncryptionAlgorithm.Rc2:    {     RC2 rc2 = new RC2CryptoServiceProvider();     rc2.Mode = CipherMode.CBC;     return rc2.CreateDecryptor(bytesKey, initVec);    }    case EncryptionAlgorithm.Rijndael:    {     Rijndael rijndael = new RijndaelManaged();     rijndael.Mode = CipherMode.CBC;     return rijndael.CreateDecryptor(bytesKey, initVec);    }     default:    {     throw new CryptographicException("Algorithm ID '" +       algorithmID +       "' not supported.");    }   }  } //end GetCryptoServiceProvider  }

     //定义加密者类 public class Encryptor {  private EncryptTransformer transformer;  private byte[] initVec;  private byte[] encKey;   public Encryptor(EncryptionAlgorithm algId)  {   transformer = new EncryptTransformer(algId);  }

      public byte[] Encrypt(byte[] bytesData, byte[] bytesKey,byte[] bytesIV)  {   //设置流对象用来保存加密数据字节流.   MemoryStream memStreamEncryptedData = new MemoryStream();      transformer.IV=bytesIV;   transformer.Key=bytesKey;     ICryptoTransform transform = transformer.GetCryptoServiceProvider(bytesKey);   CryptoStream encStream = new CryptoStream(memStreamEncryptedData,transform,CryptoStreamMode.Write);

       try   {    //将加密数据写进流对象    encStream.Write(bytesData, 0, bytesData.Length);   }   catch(Exception ex)   {    throw new Exception("在数据加密的时候出现错误!错误提示: /n"  + ex.Message);   }      //设置加密的Key和初始向量IV属性   encKey = transformer.Key;   initVec = transformer.IV;

       encStream.FlushFinalBlock();   encStream.Close();

       //Send the data back.   return memStreamEncryptedData.ToArray();  }

      public byte[] IV  {   get{return initVec;}   set{initVec = value;}  }

      public byte[] Key  {   get{return encKey;}   set{encKey = value;}  }  }

     //定义解密者类  public class Decryptor {  private DecryptTransformer transformer;  private byte[] initVec;  private byte[] encKey;

      public Decryptor(EncryptionAlgorithm algId)  {   transformer = new DecryptTransformer(algId);  }

      public byte[] Decrypt(byte[] bytesData, byte[] bytesKey,byte[] bytesIV)  {   //设置流对象用来保存解密数据字节流.   MemoryStream memStreamDecryptedData = new MemoryStream();

       //Pass in the initialization vector.   transformer.IV = bytesIV;   transformer.Key = bytesKey;

       ICryptoTransform transform = transformer.GetCryptoServiceProvider(bytesKey);   CryptoStream decStream = new CryptoStream(memStreamDecryptedData,transform, CryptoStreamMode.Write);      try   {    decStream.Write(bytesData, 0, bytesData.Length);   }   catch(Exception ex)   {    throw new Exception("在数据解密的时候出现错误!错误提示: /n" + ex.Message);   }   decStream.FlushFinalBlock();   decStream.Close();   // 返回解密数据.   return memStreamDecryptedData.ToArray();  }

      public byte[] IV  {   get{return initVec;}   set{initVec = value;}  }

      public byte[] Key  {   get{return encKey;}   set{encKey = value;}  }  }

     //类描述:文件加密/解密类 public class SecurityFile {  private DecryptTransformer Dec_Transformer;    //解密转换器  private EncryptTransformer Enc_Transformer;    //加密转换器  private byte[] initVec;  private byte[] encKey;

      public SecurityFile(EncryptionAlgorithm algId)  {   Dec_Transformer = new DecryptTransformer(algId);   Enc_Transformer = new EncryptTransformer(algId);  }

      //加密的偏移向量  internal byte[] IV  {   get{return initVec;}   set{initVec = value;}  }  //加密的密钥  internal byte[] Key  {   get{return encKey;}   set{encKey = value;}  }

      //功能描述:加密文件  public void EncryptFile(string inFileName, string outFileName, byte[] bytesKey, byte[] bytesIV)  {   try   {    FileStream fin = new FileStream(inFileName, FileMode.Open, FileAccess.Read);    FileStream fout = new FileStream(outFileName, FileMode.OpenOrCreate, FileAccess.Write);    fout.SetLength(0);           //Create variables to help with read and write.    byte[] bin = new byte[100]; //This is intermediate storage for the encryption.    long rdlen = 0;              //This is the total number of bytes written.    long totlen = fin.Length;    //This is the total length of the input file.    int len;                     //This is the number of bytes to be written at a time.     Enc_Transformer.IV=bytesIV;    Enc_Transformer.Key=bytesKey;

        ICryptoTransform transform = Enc_Transformer.GetCryptoServiceProvider(bytesKey);              CryptoStream encStream = new CryptoStream(fout, transform, CryptoStreamMode.Write);                                  //Read from the input file, then encrypt and write to the output file.    while(rdlen < totlen)    {     len = fin.Read(bin, 0, 100);     encStream.Write(bin, 0, len);     rdlen = rdlen + len;         }     encStream.Close();      fout.Close();    fin.Close();        }   catch(Exception ex)   {    throw new Exception("在文件加密的时候出现错误!错误提示: /n" + ex.Message);   }  }

      //功能描述:解密文件  public void DecryptFile(string inFileName, string outFileName, byte[] bytesKey, byte[] bytesIV)  {   try   {    FileStream fin = new FileStream(inFileName, FileMode.Open, FileAccess.Read);    FileStream fout = new FileStream(outFileName, FileMode.OpenOrCreate, FileAccess.Write);    fout.SetLength(0);           //Create variables to help with read and write.    byte[] bin = new byte[100]; //This is intermediate storage for the encryption.    long rdlen = 0;              //This is the total number of bytes written.    long totlen = fin.Length;    //This is the total length of the input file.    int len;                     //This is the number of bytes to be written at a time.     Dec_Transformer.IV=bytesIV;    Dec_Transformer.Key=bytesKey;

        ICryptoTransform transform = Dec_Transformer.GetCryptoServiceProvider(bytesKey);              CryptoStream encStream = new CryptoStream(fout, transform, CryptoStreamMode.Write);                                  //Read from the input file, then encrypt and write to the output file.    while(rdlen < totlen)    {     len = fin.Read(bin, 0, 100);     encStream.Write(bin, 0, len);     rdlen = rdlen + len;         }     encStream.Close();      fout.Close();    fin.Close();        }   catch(Exception ex)   {    throw new Exception("在文件加密的时候出现错误!错误提示: /n" + ex.Message);   }  }  }

    }

     

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