System.Web.Services.Protocols.SoapHeaderException:
System.Web.Services.Protocols.SoapHeaderException: Server unavailable, please
try later ---> System.Security.Cryptography.CryptographicException:
Cryptography_CSP_NoPrivateKey\n   at
Microsoft.Web.Services2.Security.Cryptography.RSACryptoServiceProvider.SignHash(Byte[]
rgbHash, String oidHash)\n   at
Microsoft.Web.Services2.Security.Cryptography.RSASHA1SignatureFormatter.SignHash(Byte[]
rgbHash)\n   at
Microsoft.Web.Services2.Security.Cryptography.RSASHA1SignatureFormatter.Sign(Stream
data)\n   at
Microsoft.Web.Services2.Security.MessageSignature.ComputeAsymmetricSignature(AsymmetricKeyAlgorithm
key)\n   at
Microsoft.Web.Services2.Security.MessageSignature.ComputeSignature()\n   at
Microsoft.Web.Services2.Security.Security.SerializeXml(SoapEnvelope
document)\n   at
Microsoft.Web.Services2.Security.SecurityOutputFilter.ProcessHeader(Security
security, SoapEnvelope envelope)\n   at
Microsoft.Web.Services2.Security.SecurityOutputFilter.ProcessMessage(SoapEnvelope
envelope)\n   at
Microsoft.Web.Services2.Pipeline.ProcessOutputMessage(SoapEnvelope
envelope)\n   at
Microsoft.Web.Services2.WebServicesExtension.AfterSerializeServer(SoapServerMessage
message)\n   --- End of inner exception stack trace ---\r\n   at
System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage
message, WebResponse response, Stream responseStream, Boolean asyncCall)\r\n  
at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
methodName, Object[] parameters)\r\n   at

This exception is driving me crazy.  I have installed WSE 2.0 SP3 and the
below is the code snippet that retrieves certificate from certificate store,
according to documentation i have assigned rights to ASPNET account using
WSECertificateTool.  I can see the values of certificate being written to
disk but the cryptic error message doesn't lead to any source making it
extremely difficult to debug. Would appreciate if any one can shed light on
the code . Thx for your help

    public class PostTradeService : System.Web.Services.WebService
    {
        public PostTradeService()
        {
        }

        [WebMethod]
        public int SubmitContractNote(ContractNoteInfo contractNote)
        {
            SoapContext respCtx = ResponseSoapContext.Current;
            string identifier = "GWYsQ6VRJyw6w5fgxOMgje5E92A=";
            X509CertificateStore localStore =
X509CertificateStore.LocalMachineStore(X509CertificateStore.MyStore);
            localStore.OpenRead();
            //X509CertificateCollection certCollection =
localStore.FindCertificateBySubjectString("Consumer A");
            X509CertificateCollection certCollection =
localStore.FindCertificateByKeyIdentifier(Convert.FromBase64String(identifier));
                X509Certificate provCert = certCollection[0];
                StreamWriter writer = new StreamWriter(@"C:\log.txt",false);
                writer.WriteLine(provCert.SupportsDigitalSignature);
                writer.WriteLine(provCert.SupportsDataEncryption);
                X509SecurityToken token = new X509SecurityToken(provCert);
                respCtx.Security.Tokens.Add(token);
                respCtx.Security.Elements.Add(new MessageSignature(token));
                writer.WriteLine("done");
                writer.Close();
            //Process the submitted information
            return 0;
        }