Add-Type -Path .\lib\BouncyCastle.Crypto.dll
Add-Type -AssemblyName System.Windows.Forms
$str = ""
$form = [System.Windows.Forms.Form]::new()
$form.Visible = $false
$openfiledialog = [System.Windows.Forms.OpenFileDialog]::new()
$openfiledialog.Filter = "All Signature Files | *.sig;*.sign;*.p7s | All files | *.*"
$openfiledialog.InitialDirectory = (Get-Location)
$openfiledialog.Title = "Choose digital signature"
$openfiledialog.CheckFileExists = $true
$openfiledialog.CheckPathExists = $true
$result = $openfiledialog.ShowDialog($form)
if ($result -eq [System.Windows.Forms.DialogResult]::OK)
{
	$dirPath = (Get-Location).ToString() + "\" + ($openfiledialog.FileName.ToString() | Split-Path -Leaf) + ".dir"
	$InFile = [System.IO.FileStream]::new($openfiledialog.FileName, [system.IO.FileMode]::Open)
	$SigBlock = [System.Byte[]]::new($InFile.Length)
	$InFile.Read($SigBlock, 0, $SigBlock.Length) | Out-Null
	try
	{
		$certStore = [Org.BouncyCastle.Cms.CmsSignedData]::new($SigBlock)
	}
	catch [Org.BouncyCastle.Cms.CmsException]
	{
		$SigBlock = [Org.BouncyCastle.Utilities.Encoders.Base64]::Decode($SigBlock)
		$certStore = [Org.BouncyCastle.Cms.CmsSignedData]::new($SigBlock)
	}
	[Org.BouncyCastle.X509.Store.IX509Store]$x509certs = $certStore.GetCertificates("Collection")
	[System.Collections.ArrayList]$a = [System.Collections.ArrayList]::new($x509certs.GetMatches($null))
	if ($a.Count -gt 0)
	{
		try
		{
			New-Item -ItemType Directory -Path $dirPath -ErrorAction Stop | Out-Null
		}
		catch [System.IO.IOException]
		{
			Write-Host "Directory already exists!"
		}
		for ($i = 0; $i -lt $a.Count; $i++)
		{
			[Org.BouncyCastle.X509.X509Certificate]$cert = [Org.BouncyCastle.X509.X509Certificate]$a[$i]
			$filename = $cert.SubjectDN.GetValueList([Org.BouncyCastle.Asn1.X509.X509Name]::CN) -replace '"',""
			$c = $cert.GetEncoded()
			$str = [System.Convert]::ToBase64String($c)
			Set-Content -Value ([byte[]][char[]]$str) -Path ($dirPath + "\" + $filename + ".cer") -Encoding Byte
		}
		explorer $dirPath
	}
	if ($a.Count -eq 0)
	{
		[System.Windows.Forms.MessageBox]::Show($form, "No certificates found!", "Warning!", 'OK', 'Warning')
	}
}
if ($result -ne [System.Windows.Forms.DialogResult]::OK)
{
	[System.Windows.Forms.MessageBox]::Show($form, "Aborting", "Warning!", 'OK', 'Warning')
}