Cannot acces users Active Directory password information on production server - asp.net

Question

I'm developing an MVC application and I have a routine that gets the currently logged on users password info and it works fine on my PC but when I publish my application to a live server on the domain, I don't seem to be able to gain access to the AD information. I have used very similar code in a currently running asp.net web application and it works just fine. I compared security settings on both applications and they look identical. Here is the routine:
public int GetPasswordExpiration()
{
PrincipalContext domain = new PrincipalContext(ContextType.Domain);
string currUserName = WindowsIdentity.GetCurrent().Name;
UserPrincipal currLogin = UserPrincipal.FindByIdentity(domain, currUserName);
DateTime passwordLastSet = currLogin.LastPasswordSet.Value; //here is where it chokes***
int doyPasswordSet = passwordLastSet.DayOfYear;
int doy = DateTime.Today.DayOfYear;
int daysSinceLastset = (doy - doyPasswordSet);
int daysTilDue = (120 - daysSinceLastset);
return (daysTilDue);
}
I am an administrator on the domain so I think I have an application permissions issue, but since the failing application has the same permissions as the working application, I'm not sure where to look next. Any help is appreciated.

Answer 1

I'm answernig my own question because I want to post the code that works. Wiktor Zychla nailed it when asking if WindowsIdentity.GetCurrent().Name applied to the identity of the application pool rather than the logged in user. As a matter of fact it did, thanks Wiktor!
Here is the modified code that works. I did change the way I got the users identity (explained why below).
Controller Code:
using MyProject.Utilities; // Folder where I created the CommonFunctions.cs Class
var cf = new CommonFunctions();
string user = User.Identity.Name;
ViewBag.PasswordExpires = cf.GetPasswordExpiration(user);
Code in CommonFunctions
public int GetPasswordExpiration(string user)
{
PrincipalContext ctx = new PrincipalContext(ContextType.Domain);
UserPrincipal currLogin = UserPrincipal.FindByIdentity(ctx, user);
DateTime passwordLastSet = currLogin.LastPasswordSet.Value;
int doyPasswordSet = passwordLastSet.DayOfYear;
int doy = DateTime.Today.DayOfYear;
int daysSinceLastset = (doy - doyPasswordSet);
int daysTilDue = (120 - daysSinceLastset);
return (daysTilDue);
}
The one thing that clued me in was that I decided to just run all the code in my controller and when I did, I got a red squiggly saying "The name WindowsIdentity does not exist in this context":
string currUserName = WindowsIdentity.GetCurrent().Name;
Also, the reason I retrieved User.Identity.Name in the Controller and passed it to the function is because once I got things working and wanted to thin out my controller, I tried to get User.Identity.Name in the function but I got another red squiggly with the same message under User in this line:
string user = User.Identity.Name;
So I figure this is a .net thing and just went with getting the User.Identiy.Name in the controller, pass it to the function and all is well. This one really tested my patience and I hope this post can help someone else.