ASP.NET - "Unknown user name or password" when trying to copy file to remote share

Question

I have an ASP.NET application that's trying to copy a file to a remote share that's on a server on another domain ("REMOTEDOMAIN"):

File.Copy(@"c:\Test.txt", @"\\REMOTEMACHINE\Share");

When we get to the File.Copy method, I'm getting "Login failure: Unknown user name or password" when trying to connect to the share through the local IIS install. This is despite the share itself having "Everyone" read/write permissions (temporarily, at least). The Security log on the remote server logs the same error, so I know the process is at least trying to get to the right place.

I sort of understand why, as the website's application pool is attempting to authenticate with an account on LOCALDOMAIN and not REMOTEDOMAIN.

However, the weird thing is, the entire process works fine when I test through the ASP.NET Development Server instead of IIS, despite the fact that both the Development Server and the IIS Application Pool are using the same credentials.

Any thoughts on how to further diagnose this? Unfortunately the test site has to remain on LOCALDOMAIN and the files still have to be copied to REMOTEDOMAIN; I can't move one site to the other or vice versa.

Answer 1

Everyone does not include Anonymous, so the user still needs to be in the domain of the REMOTEDOMAIN (http://support.microsoft.com/kb/278259). You could get this working by allowing "Guest", but it would be a security nightmare of course so it is not much of a help.

The solution would be to impersonate Asp.Net user: http://support.microsoft.com/kb/306158

One hack that you should know is that if the IIS is not in the remote domain, you can go around this problem, by setting up local (non-domain) users on both machines and setting the same password for both of them.

despite the fact that both the Development Server and the IIS Application Pool are using the same credentials.

Are you absolutely sure about this? If you are talking about the Visual Studio dev server, it runs on your account. And typically Asp.Net runs as "Network Service"