I needed to pass the ID/password of a service account to a Microsoft HPC grid for some jobs we were submitting automatically.  Powershell was able to do that pretty easily.

***WARNING***  This script reads a domain ID and password from an unencrypted file.  Our implementation of this script used a protected file.  Yours should too!  You’ve been warned.  I’m not responsible if your account password is compromised.

$domain      = "[Your domain name]"
$filename    = "[Path to filename]\filename"
$username    = $domain + "\" + ($username.substring(($username.Length - 5),5))
$password    = Get-Content $filename | ConvertTo-SecureString -AsPlainText -Force
$credentials = New-Object System.Management.Automation.PSCredential($username,$password)

A couple notes here.  The $filename variable is used to get the entire path of the password file.  For ease of scripting, I’ve created a file named the same as the user ID I’m using with no file extension.  In the $username line, I’ve concatenated the $domain variable, a backslash, and the user ID that I’ve derived by taking the substring of the length of the $filename variable, minus the length of the ID, plus the length.  There is a cleaner way to do this, but the ID I’m using will never change (yes, I said never), so I chose this method.

$username    = $domain + "\" + ($username.substring(($username.Length - 5),5))

From that point, we read the password from the file and pipe it into the ConvertTo-SecureString commandlet.  Since we are using a plaintext password here (see the warning above), we have to use the -AsPlainText and  -Force parameters.  If you don’t use these, PoSh will complain, you’ll be frustrated.

$password    = Get-Content $filename | ConvertTo-SecureString -AsPlainText -Force

The last line is used to actually pass the credentials to a variable that can be used in a script that requires authentication.

$credentials = New-Object System.Management.Automation.PSCredential($username,$password)