一个完整的类用来生成RSACryptoServiceProvider单例类（.NET）

 internal class CcbRsaCryptProvider
 {
         private static RSACryptoServiceProvider _providerForSign;
         private static RSACryptoServiceProvider _providerForVerifySign;
         private static readonly object SignObj = new object();
         private static readonly object VerifySignObj = new object();

         internal static RSACryptoServiceProvider GetInstanceForSign(string privateKeyFile)
         {
             if (null != _providerForSign) return _providerForSign;
             lock (SignObj)
             {
                 if (null != _providerForSign) return _providerForSign;
                 var provider = new RSACryptoServiceProvider();
                 provider.FromXmlString(GetXmlContent(privateKeyFile));
                 _providerForSign = provider;
             }
             return _providerForSign;
         }

         internal static RSACryptoServiceProvider GetInstanceForVerifySign(string publicKeyFile)
         {
             if (null != _providerForVerifySign) return _providerForVerifySign;
             lock (VerifySignObj)
             {
                 if (null != _providerForVerifySign) return _providerForVerifySign;
                 var provider = new RSACryptoServiceProvider();
                 provider.FromXmlString(GetXmlContent(publicKeyFile));
                 _providerForVerifySign = provider;
             }
             return _providerForVerifySign;
         }

         private static string GetXmlContent(string filePath)
         {
             return File.ReadAllText(filePath);
         }

         private CcbRsaCryptProvider()
         {
         }
     }