Recently we ran into an issue where Custom Forms Based
Authentication was failing on MAC machine. The FBA was configured properly
without any issues and is working like charm with Windows OS. Did few searches
on Google and found that few of them have faced the issues but in a different
scenario and following were the work around or fixes were suggested.
- Most of them have either wrongly configured Form
Based Authentication and on proper configuration it started to work.
- For few the Claims to Windows Token had stopped,
and on restart of the services FBA started working.
- Few also suggested the performing an IISRESET on
the server solved their issues.
- In some case the APP Pool Credentials for
Security token services was wrong.
All the above 4 fixes where not valid in my scenario since
FBA was working perfectly fine with windows OS.
In order to get to the root cause I had to go through the traditional
approach of visiting event viewer and SharePoint logs. On analyzing the event
viewer log it was found that the Secure Token Service was not getting generated
for the users who were trying to log into the SharePoint 2010 site using FBA
from Safari browser on MAC machine.
In order to get more exception details in the event viewer,
add the following <serviceDebug includeExceptionDetailInFaults="True" httpHelpPageEnabled="True"/> tag in web.config of Security Token
Webservices which resides at the following location “C:\Program Files\Common
Files\Microsoft Shared\Web Server Extensions\14\WebServices\SecurityToken”
On restarting the services details of the exception was
logged as follows.
Event: 8306, SharePoint Foundation
Task Category: Claims Authentication
Exception Details: An exception occurred when trying to
issue security token: Object reference not set to an instance of an object.
On seeing this exception we re-visited the Custom Forms
Login page which we had created for FBA.
On debug we noticed that the below link threw the above exception
SPClaimsUtility.AuthenticateFormsUser(Context.Request.UrlReferrer,txtusername.Text, txtpassword.Text);
It was certain that the issues was with Context.Request.UrlReferrer
passed to the SPClaimsUtility.AuthenticateFormsUser method. In order to get this working we modified the way we were
passing URL parameter to the below approach.
string siteUrl = SPContext.Current.Site.Url;
string extraneturl = siteUrl.ToString();
Uri extrametUri = new Uri(extraneturl);
bool status = SPClaimsUtility.AuthenticateFormsUser(extrametUri,
txtusername.Text, txtpassword.Text); and FBA started working on MAC.
Hope this post would help anyone facing similar
issue. Please feel free to drop any comment or any other alternate approach.
