C# - Not able to validate local machine user when ".\" is pre-append with username

Question

I’m using System.DirectoryServices.AccountManagement library to validate a local user.

I’ve got the following code:

  private bool IsValidWindowsUser(string userName, string password)
  {
       using (var p = new PrincipalContext(ContextType.Machine))
            return p.ValidateCredentials(userName, password);
  }

But whenever I am passing correct username with ".\" preappend e.g if the user is name is "test" and if I am passing username like ".\test" then it is giving me an exception

The network path was not found.

Can somebody please help me. If I remove ".\" then it is working fine.

My another condition is I only want to validate Local machine user not domain user.

Please help

Why do you preapoend '.\' ? Wouldn't it work if you preappend the name of the maschine followed by "\"? — Daniel Abou Chleih, Sep 18 '13 at 05:32
Actually we have one database where user is already saved with ".\" pre-appended value. — Durgaprasad Budhwani, Sep 18 '13 at 05:56
What you put in front of the backslash selects the context for the user account. But you already selected the context with the PrincipalContext constructor. You can't do it both ways. — Hans Passant, Sep 18 '13 at 12:55

score 0 · Answer 1 · answered Sep 18 '13 at 05:32

0

Try this:

p.ValidateCredentials(Environment.MachineName + "\\" + userName, password);

answered Sep 18 '13 at 05:32

alex.b

4,547
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Hi Aleksey, Actually we dont want to anything like Environment.MachineName but we only want to validate ".\test" user with ValidateCredentials api. – Durgaprasad Budhwani Sep 18 '13 at 05:58
Can you please tell why you don't want to use Environment.MachineName? I'm just being curios – alex.b Sep 18 '13 at 06:05
Actually that username is hardcoded in database, and we are trying to find an alternative to use existing username and validate with local machine. – Durgaprasad Budhwani Sep 18 '13 at 06:32
Why do you save them the username with '.\'? That doesn't really make sense. – Daniel Abou Chleih Sep 18 '13 at 08:54

score 0 · Answer 2 · answered Jul 26 '19 at 17:07

Here's what I got working, in case someone else is having similar issue.

 string GetLogin(string s)
    {
        string regex = @"^(.*\\)?([^\@]*)(@.*)?$";
        return Regex.Replace(s, regex, "$2", RegexOptions.None);
    }

using (PrincipalContext pcLocal = new PrincipalContext(ContextType.Machine))
            {
                try
                {
                            try
                            {
                                if (null != group && pcLocal.ValidateCredentials($".\\{username}", password))
                                {
                                    return GetLogin(findByIdentity.SamAccountName);
                                }
                            }
                            catch (Exception)
                            {
                                string user = GetLogin(username);

                                if (null != group && pcLocal.ValidateCredentials(user, password))
                                {
                                    return GetLogin(findByIdentity.SamAccountName);
                                }
                            }

                }
                catch (Exception e)
                {
                    throw e;
                }
            }

C# - Not able to validate local machine user when ".\" is pre-append with username

2 Answers2