Functions/Convert-DryADEncryptedBase64StringToClearText.ps1
# DryActiveDirectory is an AD config module for use with DryDeploy, or by itself. # # Copyright (C) 2021 Bjørn Henrik Formo (bjornhenrikformo@gmail.com) # LICENSE: https://raw.githubusercontent.com/bjoernf73/DryActiveDirectory/main/LICENSE # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Function Convert-DryADEncryptedBase64StringToClearText { [CmdletBinding()] [OutputType([System.String])] Param( [Parameter(Mandatory)] [ValidateNotNullOrEmpty()] [String] $EncryptedBase64String ) Try { # Try to find a certificate in the LocalMachine\My (Personal) Store with # - a private key accessible # - of type SHA256 RSA (ECDH does not work) # - 'Server Authentiaction' as part of the Enhanced Key Usage $Cert = Get-ChildItem -Path Cert:\LocalMachine\My -ErrorAction Stop | Where-Object { ($_.HasPrivateKey -eq $True) -and ($_.SignatureAlgorithm.FriendlyName -eq 'SHA256RSA') -and (@(($_.EnhancedKeyUsageList).FriendlyName) -contains 'Server Authentication') } # If multiple, use first If ($Cert -is [Array]) { $Cert = $Cert[0] } If ($Cert) { $EncryptedByteArray = [Convert]::FromBase64String($EncryptedBase64String) $ClearText = [System.Text.Encoding]::UTF8.GetString($Cert.PrivateKey.Decrypt($EncryptedByteArray,$true)) } Else { Throw "Server Authentication Certificate with Private Key not found!" } Return $ClearText } Catch { $PSCmdlet.ThrowTerminatingError($_) } } |