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POPowershell - "Clear-Item variable:" vs "Remove-Variable"
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copied!<p>When storing text temporarily in powershell variables at runtime, what is the most efficient way of removing a variables contents from memory when no longer needed?</p> <p>I've used both <code>Clear-Item variable:</code> and <code>Remove-Variable</code> but how quickly does something get removed from memory with the latter vs nulling the memory contents with the former?</p> <p>EDIT: I should have made it a little clearer why I am asking.</p> <p>I am automating RDP login for a bunch of application VMs (application doesn't run as a service, outsourced developers, long story).</p> <p>So, I am developing (largely finished) a script to group launch sessions to each of the VMs. </p> <p>Idea is that the script function that stores credentials uses <code>read-host</code> to prompt for hostname then <code>get-credentials</code> to pick up domain/user/password.</p> <p>The pass is then converted from secure-string using 256-bit key (runtime key unique to machine/user that stored the creds and runs the group launch). </p> <p>The VMs name, domain, user and encrypted pass are stored in a file. When launching a session, the details are read in, password decrypted, details passed to <code>cmdkey.exe</code> to store <code>\generic:TERMSRV</code> credential for that VM, clear plaintext pass variable, launch mstsc to that host, a few seconds later remove the credential from windows credential store. (If I passed password to cmdkey.exe as anything other than plaintext, the RDP session would either receive incorrect or no credentials).</p> <p>So, hence the question, I need the password In plaintext to exist in memory for as short a time as possible.</p> <p>To keep security guys happy, the script itself is aes256 encrypted and a c# wrapper with its own ps host reads, decrypts and runs the script, so there is no plaintext source on the machine that runs this. (Encrypted source on a file share so effectively I have a kill switch, can simply replace encrypted script with another displaying a message that this app has been disabled)</p>

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