API is returning error when using RESTSHARP

Question

When use RestSharp to call an API I get this error:

The underlying connection was closed: An unexpected error occurred on a send.

I've verified that my client ID, secret, username, and password are correct. I'm able to do this without issues in PowerShell.

public string GetTokenForBrightIdea()
{
    RestClient restclient = new RestClient(_uri);
    RestRequest request = new RestRequest() { Method = Method.POST };

    request.AddHeader("Accept", "application/json");
    request.AddHeader("Content-Type", "application/x-www-form-urlencoded");
    request.AddParameter("grant_type", "password");
    request.AddParameter("client_id", _clientId);
    request.AddParameter("client_secret", _clientSecret);
    request.AddParameter("username", _clientUsername);
    request.AddParameter("password", _clientPassword);

    var tResponse = restclient.Execute(request);
    var responseJson = tResponse.Content;
    return JsonConvert.DeserializeObject<Dictionary<string, object>>(
        responseJson)["access_token"].ToString();
}

What am I missing when using RestSharp to make this work?

Look at this request in Fiddler, and look at the request you made from Powershell. Compare the two. See what's different, identify what you need to change. — , Jan 31 '18 at 18:53

score 46 · Accepted Answer · answered Jan 31 '18 at 20:35

46

So it turns out that because this call was HTTPS i needed to add the following line of code

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;

answered Jan 31 '18 at 20:35

Funkel

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1

Adding the security protocol to tls12 resolved the problem – Shyam Narayan Oct 05 '20 at 08:14

score 11 · Answer 2 · answered Jan 11 '19 at 20:07

11

For .Net 3.5 and 4.0 you could try putting this line of code prior to the initialization of the RestSharp client:

ServicePointManager.SecurityProtocol = (SecurityProtocolType)768 | (SecurityProtocolType)3072;

answered Jan 11 '19 at 20:07

John Meyer

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This worked wonders after such frustrating periiod of exploring! Has to be included for ,net framework 4.0 (maybe 3.5 too) whether it's rest sharp client, or a Web client! – sanrnsam7 Mar 18 '21 at 13:15

score 2 · Answer 3 · answered Jan 25 '19 at 10:59

2

This worked fine for me:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12;

answered Jan 25 '19 at 10:59

Anjan Kant

4,090
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API is returning error when using RESTSHARP

3 Answers3

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