RestRequest works local but not from azure "The request was aborted: Could not create SSL/TLS secure channel."

Question

When I run my app in localhost it works fine but when I publish it to Azure my request stop working. Getting the error : "The request was aborted: Could not create SSL/TLS secure channel."

I have an app that calls a external commercial Soap-API. The external API requires a client certificate to be passed along as I make the requests and it also needs my ip address to be whitelisted.

The commercial API have whitelisted the IP's that I got from my app service/properties/outgoing & virtual IP addresses in Azure

I've added my client certificate file(.p12) to a folder in my solution and when checking the files uploaded to azure I can see it there as well.

Using RestSharp, my request looks like:

   private string RequestToBv(string pXml)
    {            
        X509Certificate2 cert = new X509Certificate2(bvCertificatePath, bvCertificatePassword);

        var client = new RestClient(mXmlApiUrl); //mXmlApiUrl = url to endpoint
        client.Timeout = -1;
        client.ClientCertificates = new X509CertificateCollection() { cert };
        var request = new RestRequest(Method.POST);
        request.AddHeader("Content-Type", "application/xml");
        request.AddParameter("application/xml", pXml, ParameterType.RequestBody);

        IRestResponse response = client.Execute(request);

        if (response.StatusCode == HttpStatusCode.OK)
        {
            return response.Content;
        }

        return "";
    }

When debugging in Azure I get StatusCode = 0 and the error message: "The request was aborted: Could not create SSL/TLS secure channel."

After searching stackoverflow for answers I've to add following lines of code at the top of my method:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
        ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, errors) => true;

But I still get the same error response.

Is there any settings I need to set in Azure or install my client certificate in some way on Azure?

Additional info after comment:

Answer 1

What I had to do was to convert my .p12 Certificate file to crt file, import it to Azure and then use X509Store in my code to get it. After that the handshake was successful