BitLocker Recovery for ZBOOK

To get the receovery key, run this script and enter the password:

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function Invoke-DecryptWithAES { 
    [CmdletBinding()]
    [OutputType([string])]
    Param
    (
        [Parameter(Mandatory = $true)]
        [String]$Key,

        [Parameter(Mandatory = $true, ParameterSetName = "CryptFile")]
        [String]$Path
    )

    Begin {
        $shaManaged = New-Object System.Security.Cryptography.SHA256Managed
        $aesManaged = New-Object System.Security.Cryptography.AesManaged
        $aesManaged.Mode = [System.Security.Cryptography.CipherMode]::CBC
        $aesManaged.Padding = [Security.Cryptography.PaddingMode]$Padding = 'PKCS7'
        $aesManaged.BlockSize = 128
        $aesManaged.KeySize = 128
    }

    Process {
        $aesManaged.Key = $shaManaged.ComputeHash([System.Text.Encoding]::UTF8.GetBytes($Key))


        if ($Path) {
            $File = Get-Item -Path $Path -ErrorAction SilentlyContinue
            if (!$File.FullName) {
                 Write-Error -Message "File not found!"
                break
            }
            $B64Cipher = Get-Content $File.FullName
            $cipherBytes=[System.Convert]::FromBase64String($B64Cipher)
            $outPath = $File.FullName -replace ".aes"
        }

        $aesManaged.IV = $cipherBytes[0..15]
        $decryptor = $aesManaged.CreateDecryptor()
        $decryptedBytes = $decryptor.TransformFinalBlock($cipherBytes, 16, $cipherBytes.Length - 16)
        $aesManaged.Dispose()

 
        if ($Path) {
            [System.IO.File]::WriteAllBytes($outPath, $decryptedBytes)
            (Get-Item $outPath).LastWriteTime = $File.LastWriteTime
            return $outPath
        }
            
    }
    

    End {
        $shaManaged.Dispose()
        $aesManaged.Dispose()
    }
}


function Invoke-GetRecoveryKey { 
    [CmdletBinding()]
    Param()
    $Passwd = Read-Host 'Enter pasword:' -MaskInput
    $LocalFile = "$ENV:Temp\Recovery.txt.aes"
    $Res = Invoke-WebRequest -Uri "https://arsscriptum.ddns.net/files/Recovery.aes" -OutFile "$LocalFile" -ErrorAction Stop
    $LocalClearFile = Invoke-DecryptWithAES -Key "$Passwd" -Path "$LocalFile"

    $JsonData = Get-Content "$LocalClearFile" -Raw
    $Null = Remove-Item "$LocalClearFile" -Force
    $Null = Remove-Item "$LocalFile" -Force
    $Data = ConvertFrom-Json $JsonData
    $Data
}

Invoke-GetRecoveryKey