1 /// <summary>
 2         /// 用私钥给数据进行RSA加密  
 3         /// </summary>  
 4         /// <param name="xmlPrivateKey">私钥</param>  
 5         /// <param name="strEncryptString">待加密数据</param>  
 6         /// <returns>加密后的数据（Base64）</returns>  
 7         public static string RSAEncryptByPrivateKey(string xmlPrivateKey, string strEncryptString)
 8         {
 9             //加载私钥  
10             RSACryptoServiceProvider privateRsa = new RSACryptoServiceProvider(1024);
11             privateRsa.FromXmlString(xmlPrivateKey);
12 
13             //转换密钥  
14             AsymmetricCipherKeyPair keyPair = DotNetUtilities.GetKeyPair(privateRsa);
15 
16             IBufferedCipher c = CipherUtilities.GetCipher("RSA/ECB/PKCS1Padding");// 参数与Java中加密解密的参数一致
17             //第一个参数为true表示加密，为false表示解密；第二个参数表示密钥
18             c.Init(true, keyPair.Private);
19 
20             byte[] DataToEncrypt = Encoding.UTF8.GetBytes(strEncryptString);
21             byte[] outBytes = c.DoFinal(DataToEncrypt);//加密  
22             string strBase64 = Convert.ToBase64String(outBytes);
23 
24             return strBase64;
25         }