Get Users SID with PowerShell

Mario Majcica March 3, 2018 0 Comments

What is a User SID? It is user’s unique identifier, usually used in application to relate to a user in a unique way. Microsoft defines SID in the following way:

A data structure of variable length that identifies user, group, and computer accounts. Every account on a network is issued a unique SID when the account is first created. Internal processes in Windows refer to an account’s SID rather than the account’s user or group name.

Applications as TFS, MDS, etc use SID to relate to a user in their databases. For various reasons you may need to retrieve the SID for a given user in order to perform the desired operation. There are multiple ways of obtaining it, and what I do often see is leveraging the ActiveDirectory module in order to retrieve such a simple metric. Although ActiveDirectory module is a powerful it is an overkill for this particular task.
There is a much simpler way to retrieve it and that is by leveraging the .Net classes. Following is a call packed in a cmdlet.

function Get-UserSid
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)] [string]$Username
    )
    BEGIN
    {
        Write-Verbose "Entering script $($MyInvocation.MyCommand.Name)"
        Write-Verbose "Parameter Values"
        $PSBoundParameters.Keys | ForEach-Object { Write-Verbose "$_ = '$($PSBoundParameters[$_])'" }
    }
    PROCESS
    {
        if ($Username.Contains("\"))
        {
            $dl = $Username -split "\\"
        
            $domain = $dl[0]
            $user = $dl[1]

            $objUser = New-Object System.Security.Principal.NTAccount($domain, $user)
            $strSID = $objUser.Translate([System.Security.Principal.SecurityIdentifier]) 
            
            return $strSID.Value
        }
        else
        {
            throw "Username not in down-level logon name format (DOMAIN\UserName)."
        }
    }
    END { }
}

In case your computer is not part of a domain, you can just pass in as the domain parameter the host name.

This kind of information is relatively easy to find, I still wrote this as a reminder for myself.

Still, I hope it can help someone.

Using Git with self-signed certificate at the user level

Mario Majcica May 31, 2017 0 Comments

Introduction

Some time ago I wrote about Installing self-signed certificates into Git cert store.
With the advent of Visual Studio 2017 and updates of the Git client I noticed the limitation of this approach. Also, updates of Visual Studio brought updates to a git client and after each update, my self signed certificate was gone. As this fact annoyed me quite a bit, I looked for a better approach.

A better approach

In order to solve this issue, I needed to move my certificate authority file to a place where it will not be rewritten by installing a new version of Git client. I went moving it to my users directory, which on my PC equals to C:\Users\majcicam. So after adding my self signed certificate into ca-bundle.crt file that is located, again, in my case at C:\Program Files\Git\mingw64\ssl\certs, I moved it to the C:\Users\majcicam. You can read more about adding your self signed certificate into the ca-cert file in my previous post at Installing self-signed certificates into Git cert store.

After I moved my file, I needed to indicate to the Git client that he should use this file to verify certificates. This can be done by issuing the following command:

git config --global http.sslCAInfo C:/Users/majcicam/ca-bundle.crt

This command will add the new path into a Git global config file which is a place where all of the user wide settings are stored and it is not subjective to the installation of Git or a particular repository.

Note that I used a slashes in the path instead of back-slashes.

This means that now we can update our Git client and that these settings will be maintained. As a standard on Windows platform, it is located in your user folder, in my case the global config file is at C:/Users/majcicam/.gitconfig. You can verify the values of all the Git config files and their location by issuing the following command:

git config --list --show-origin

This simple trick should make your lazy developer life a bit easier.

Happy coding