Access Project online api on sharepoint online on c#

Question

I have a sharepoint (myAzure.sharepoint.com). Inside I got a site PWA (project online). PWA offert OData Api. The security of that Api required a User member of your AD (not an app).

I want, in c#, to consumme the api outside azure (like localhost). I need to do it without interractive (web promp interraction with the user).

Answer 1

The only way I found was by "password credential".

string url = $"https://login.microsoftonline.com/{myTenantId}/oauth2/v2.0/token";
var formData = new NameValueCollection();
formData.Add("client_id", clientId);
formData.Add("client_secret", clientSecret);
formData.Add("username", username);
formData.Add("password", password);
formData.Add("scope", $"https://{myAzure}.sharepoint.com/.default");
formData.Add("grant_type", "password");
string encodedFormData = string.Join("&", Array.ConvertAll(formData.AllKeys, key =>
string.Format("{0}={1}", Uri.EscapeDataString(key), Uri.EscapeDataString(formData[key]))));

var request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";

byte[] formDataBytes = Encoding.UTF8.GetBytes(encodedFormData);
request.ContentLength = formDataBytes.Length;
using (var requestStream = request.GetRequestStream())
{
    requestStream.Write(formDataBytes, 0, formDataBytes.Length);
}

using (var response = (HttpWebResponse)request.GetResponse())
{
    using (var responseStream = response.GetResponseStream())
    {
        if (responseStream != null)
        {
            using (var reader = new System.IO.StreamReader(responseStream))
            {
                string responseContent = reader.ReadToEnd();
                JObject jsonResponse = JObject.Parse(responseContent);
                string accessToken = (string)jsonResponse["access_token"];

                using (HttpClient client = new HttpClient())
                {                                
                    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
                    HttpResponseMessage response2 = await client.GetAsync($"https://{myAzure}.sharepoint.com/sites/{myPWASite}/_api/ProjectData/Ressources");
                 
                    if (response2.IsSuccessStatusCode)
                    {
                        string responseBody = await response2.Content.ReadAsStringAsync();
                        Console.WriteLine(responseBody);
                    }
                    else
                    {
                        Console.WriteLine("Erreur: " + response.StatusCode);
                    }
                }
            }
        }
    }
}

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Explanatory documentation

• https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth-ropc
• https://techcommunity.microsoft.com/t5/project-support-blog/app-user-authentication-and-project-online-development/ba-p/1925443
• https://learn.microsoft.com/en-us/azure/data-factory/connector-odata?tabs=data-factory#copy-data-from-project-online