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); } } }
}
