Powershell Credentials

I’ve only recently started using PowerShell to perform automated batch functions, and storing passwords in plain text is a huge problem. In other languages, I crypt the password with a string stored elsewhere, then use the elsewhere-stored string in conjunction with the cipher text to retrieve the password. There’s a really easy way to accomplish this in PowerShell (although it does not split the credential into two separate entities that force an attacker to obtain something from two places {i.e. reading a file on disk is good enough} but if they’re already reading my code and on my server … the attacker could easily repeat the algorithmic process of retrieving the other string … which is a long way to say the PowerShell approach may seem less secure; but, effectively, it isn’t much less secure)

The first step is to store the password into a file. Use “read-host -AsSecureString” to grab the password from user input, pipe that to convertfrom-securestring to turn it into a big ugly jumble of text, then pipe that out to a file

read-host -assecurestring | converfrom-securestring | out-file -filepath c:\temp\pass.txt

View the content of the file and you’ll see … a big long hex thing

Great, I’ve got a bunch of rubbish in a file. How do I use that in a script? Set a variable to the content of the file piped through convertto-securestring and then use that password to create a new PSCredential object

$strPassword = get-content -path c:\temp\pass.txt | convertto-securestring
$cred = new-object -typename PSCredential -argumentlist ‘UserID’,$strPassword

Voila, $cred is a credential that you can use in other commands.

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