Validate a username and password against Active Directory?


How can I validate a username and password against Active Directory? I simply want to check if a username and password are correct.

11/5/2012 4:42:39 PM

If you work on .NET 3.5 or newer, you can use the System.DirectoryServices.AccountManagement namespace and easily verify your credentials:

// create a "principal context" - e.g. your domain (could be machine, too)
using(PrincipalContext pc = new PrincipalContext(ContextType.Domain, "YOURDOMAIN"))
    // validate the credentials
    bool isValid = pc.ValidateCredentials("myuser", "mypassword");

It's simple, it's reliable, it's 100% C# managed code on your end - what more can you ask for? :-)

Read all about it here:


As outlined in this other SO question (and its answers), there is an issue with this call possibly returning True for old passwords of a user. Just be aware of this behavior and don't be too surprised if this happens :-) (thanks to @MikeGledhill for pointing this out!)

5/23/2017 12:34:45 PM

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