Hi,

I need to connect to a provider's web service with a Windows Form application. He gives me a certificate to access it but I have a security problem.

I have done these following steps :

1. Add certificate to personal store (on IE & Firefox)
2. Generate a proxy with the remote wsdl (no problem)

3. Use this code to call a method :
   

   `using (service1.MessagesService m = new service1.MessagesService()) {
   
   X509Certificate crt = new X509Certificate(@"C:\OpenSSL\bin\thecert.p12",string.Empty);
   m.ClientCertificates.Add(crt);
   var result = m.AuthoriseTransaction(aut);

   this.textBox1.AppendText(result.id.ToString());
   }`
   

I have the following error :
The underlying connection was closed: Could not establish trust relationship for the channel SSL / TLS.

Thanks for your help