Graph API- Refresh Token- Bad Request 400

Question

The goal it use Graph API to send an email. I am able to get the Authorization token by using the below code - https://login.microsoftonline.com/Some_Tenant_ID/oauth2/v2.0/authorize?client_id=SOME_Client_ID&response_type=code&redirect_uri=https://localhost&response_mode=query&scope=offline_access%20user.read%20mail.read&state=12345

The scope is user.read and mail.send with offline access. Now from using this authorization code, I want to get the refresh token. From my understanding this should work without any problem but for some reason the code is breaking at this line var httpResponse = (HttpWebResponse)request.GetResponse(); and I not sure why.

The exception code error 400 Bad Request. my console output.

Can any one help me here and is there another way to get the Access token and/or refresh token from Authorization token. the end goal is to send email from graph API.

string tokenUrl = "https://login.microsoftonline.com/myAppTenantID/oauth2/token";
//string tokenUrl = "https://login.microsoftonline.com/myAppTenantID/oauth2/v2.0/token"; I have tried this URL too
string grant_type= "authorization_code";
string ClientID = "MyAppClientID";
string Auth_Code = "My Auth Code";
string RedirectURI = "https://localhost";
string ClientSecret = "my App secret";
Dictionary<string, string> res_dic = null;
string TargetURL = String.Format(tokenUrl);
var request = (System.Net.HttpWebRequest)WebRequest.Create(TargetURL);
request.ContentType = "application/x-www-form-urlencoded";
string RefreshToken = null;


string requestBody = String.Format(@"client_id={0}&scope=user.read%20mail.read&code={1}&redirect_uri={2}&grant_type=authorization_code&client_secret={3}", ClientID, Auth_Code,RedirectURI, ClientSecret);
request.Method = "POST";
using (var streamwriter = new StreamWriter(request.GetRequestStream()))
{
    Console.WriteLine("stage 0....");
    streamwriter.Write(requestBody);
    streamwriter.Flush();
    streamwriter.Close();
}
try
{
    Console.WriteLine("stage 1....");
    //Console.WriteLine("prting response"+ (HttpWebResponse)request.GetResponse());
    var httpResponse = (HttpWebResponse)request.GetResponse();
    Console.WriteLine("Stage 2....");
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        Console.WriteLine("Stage 3");
        string Result = streamReader.ReadToEnd();
        string StatusCode = httpResponse.StatusCode.ToString();
        res_dic = JsonConvert.DeserializeObject<Dictionary<string, string>>(Result);
    }
}
catch (WebException ex)
{
    Console.WriteLine("stage 4");
    string ErrorMessage = ex.Message.ToString();
    Console.WriteLine(ErrorMessage);
}
RefreshToken = res_dic["refresh_token"].ToString();

}

Pamela Peng Pamela Peng · Accepted Answer · 2020-11-29T06:02:53

This is better for you to debug for full error message, there are many situations where this error occurs.

The scope in your code needs to add offline_access because refresh_token will be only provided if offline_access scope is requested.

You could use SDK. Code sample here:

string[] scopes = new string[] { "", "" };

IConfidentialClientApplication app = ConfidentialClientApplicationBuilder
    .Create(clientId)
    .WithRedirectUri(redirectUri)
    .WithClientSecret(clientSecret)
    .WithAuthority(authority)
    .Build();

AuthorizationCodeProvider auth = new AuthorizationCodeProvider(app, scopes);

GraphServiceClient graphServiceClient = new GraphServiceClient(new DelegateAuthenticationProvider(async (requestMessage) => {

    // Retrieve an access token for Microsoft Graph (gets a fresh token if needed).
    var authResult = await app.AcquireTokenByAuthorizationCode(scopes, auth_code).ExecuteAsync();

    // Add the access token in the Authorization header of the API request.
    requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", authResult.AccessToken);
    
})
);

And this API is used for sending mail, you need to add Mail.Send permission first.

var message = new Message
{
    Subject = "Meet for lunch?",
    Body = new ItemBody
    {
        ContentType = BodyType.Text,
        Content = "The new cafeteria is open."
    },
    ToRecipients = new List<Recipient>()
    {
        new Recipient
        {
            EmailAddress = new EmailAddress
            {
                Address = "[email protected]"
            }
        }
    },
    CcRecipients = new List<Recipient>()
    {
        new Recipient
        {
            EmailAddress = new EmailAddress
            {
                Address = "[email protected]"
            }
        }
    }
};

var saveToSentItems = false;

await graphClient.Me
    .SendMail(message,saveToSentItems)
    .Request()
    .PostAsync();

Graph API- Refresh Token- Bad Request 400

1 Answers