Safari problems accessing Windows Integrated Authentication (aka NTLM) protected web site

iis authentication safari ntlm wia
Darren picture Darren · Apr 3, 2009 · Viewed 12.2k times · Source

Our web application uses Windows Integrated Authentication (aka NTLM Auth) for security.

It's working fine for both IE and Firefox users, but Safari users are seeing intermittent problems. Browsing the site will work fine, but every once in a while there will be problems loading elements of a page (e.g. CSS or JS files). Reload and the problem will go away.

If we use a debugging proxy (Fiddler) we can see that there is a lot of extra 401 requests happening with Safari. Every once in a while a request for a resource will get stuck in a 401 request loop, and eventually fail.

I can't see anything that we're doing to cause this, and it would appear that it's a bug in Safari. Has anyone ran across this issue before, and have any suggestions for a resolution?

Thanks,

Darren.

Answer

Christopher G. Lewis picture Christopher G. Lewis · Apr 3, 2009

Some web sites http://www.musteat.org/nodes/show/151 indicate this is an issue with negotiated authentication.

You can turn off Negotiate in favor of pure NTLM in IIS via the NTAuthenticationProviders Metabase setting, and the following ADSUTIL command.

cscript adsutil.vbs set w3svc/WebSite/<SiteID>/NTAuthenticationProviders "NTLM"

Change < SiteID > to the appropriate ID, typically 1.

Related questions

How to enable windows authentication through a reverse proxy?

Sorry if it is a duplicate, as I am not a security nor network expert I may have missed the correct lingo to find information. I am working on an application to intercept and modify HTTP requests and responses between …

Read More
Configuring NuGet server to use Authentication

The release notes for NuGet 1.5 state NuGet now supports connecting to private repositories that require basic or NTLM authentication. However, the link contained in there simply leads to the hosting your own nuget feeds page, without any further mention of …

Read More
Getting IIS to impersonate the windows user to SQL server in an intranet environment

I am developing an intranet site using C# and ASP.NET MVC. I have SQL Server on one machine and IIS running on a separate machine. I would like a user to visit the intranet site and without prompting the …

Read More