Sharepoint Search REST API - 401 unauthorized Error (Need Help)

Question

I am getting 401 unauthorized error when calling a sharepoint search rest api (http://:/_api/search/query?querytext=) from a .net application using claims based authentication.

My request and error as below

private void GetSearchResponse(HttpWebRequest httpWebRequest)
{
    try
    {
        using (var httpWebResponse = httpWebRequest.GetResponse() as HttpWebResponse)
        {
            using (var stream = httpWebResponse.GetResponseStream())
            {
                ProcessSearchResponse(stream);
            }
        }
    }
    catch (WebException ex)
    {//catch and log the error
    } 

stack trace : "{\"error\":{\"code\":\"-2147024891, System.UnauthorizedAccessException\",\"message\":{\"lang\":\"en-US\",\"value\":\"Access denied. You do not have permission to perform this action or access this resource.\"}}}"

Thanks a lot in advance for your help and time.

Answer 1

Since SharePoint Online/Office 365 relies on Claims authentication use:

• SharePointOnlineCredentials class to provide credentials to access SharePoint Online resources.
• specify X-FORMS_BASED_AUTH_ACCEPTED HTTP header

The following example demonstrates how to consume SharePoint Search REST using HttpWebRequest class:

public static SharePointOnlineCredentials PrepareSPOCredentials(string userName, string passWord)
{
    var securePassWord = new SecureString();
    foreach (var c in passWord.ToCharArray()) securePassWord.AppendChar(c);
    var credentials = new SharePointOnlineCredentials(userName, securePassWord);
    return credentials;
}

public static string ExecuteSearchRequest(Uri address,ICredentials credentials,string query)
{
   string result;
   var endpointUrl = new Uri(address,string.Format("/_api/search/query?querytext='{0}'",query));

   var request = WebRequest.Create(endpointUrl) as HttpWebRequest;
   request.Credentials = credentials;
   request.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
   request.Method = "GET";
   request.Accept = "application/json; odata=verbose";
   var response = request.GetResponse();
   using (var reader = new StreamReader(response.GetResponseStream()))
   {
       result = reader.ReadToEnd();
   }
   return result;
}


//Usage
var credentials = PrepareSPOCredentials(userName, password);
var result = ExecuteSearchRequest(webUri, credentials, "contentclass:STS_ListItem AND ContentType:Task");

Answer 2

The Search results have results which the particular user does not have access to . That is why you receive forbidden error .

While using the REST API provides a much more succinct way to retrieve data, there are apparently areas where you’ll need to use the more robust CSOM.

Answer 3

I have been using below. Worked for me for 10 days. Not sure what happened after that. The user account is still a SCA on the site and the password is still valid.

var securePassword = new SecureString();
                    foreach (var c in GlobalVar.siteSCAPassword)
                    {
                        securePassword.AppendChar(c);
                    }
                    credentials = new SharePointOnlineCredentials(GlobalVar.siteSCAUserName, securePassword);

using (var client = new WebClient())
                    {
                        client.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
                        client.Credentials = credentials;
                        client.Headers.Add(HttpRequestHeader.ContentType, "application/atom+xml;type=entry");
                        client.Headers.Add(HttpRequestHeader.Accept, "application/atom+xml");

                        #region TOTAL PAGES
                        WriteLog("===TOTAL PAGES");
                        var uriTP = new Uri(GlobalVar.siteUrl + GlobalVar.searchApiSuffix + @"'*'&trimduplicates=false&rowlimit=10000&selectproperties='Title'&sourceid='fba6c3ac-3b5f-4714-9e27-87637da9e5fd'");
                        uriTP = new Uri(GlobalVar.siteUrl + GlobalVar.searchApiSuffix + @"'*'&trimduplicates=true&rowlimit=10&selectproperties='Title'");
                        WriteLog("Rest API : " + uriTP.AbsoluteUri);
                        var resultTP = client.DownloadString(uriTP);
}

The bottom line var resultTP = client.DownloadString(uriTP); now starts throwing 401 (unauthorized) error.