setting secrets in powershell - terminate once session finishes

secrets.cmd

@echo OFF
set POWERSHELL_SCRIPT=^
$securePwd = Read-Host "Enter passphrase" -AsSecureString; ^
$plainPwd =[Runtime.InteropServices.Marshal]::PtrToStringAuto([Runtime.InteropServices.Marshal]::SecureStringToBSTR($securePwd));^
Write-Host $plainPwd

for /f %%a in ('powershell -Command "&{%POWERSHELL_SCRIPT%}"') do (
  set "USER_SECRET=%%~a"
  set "ARTIFACTS_SECRET=%%~a"
)

set "ARTIFACTS_USER=JORDAN-CARSON"

set POWERSHELL_SCRIPT=