Powershell script to extract DoD Certificates into a complete chain (for use with Apache), individual certificate files, and a Java Keystore containing the complete certificate chain (for use with Tomcat)

extract_dod_certs.ps1

# Exports the entire DoD CA Certificate chain as DoD_CAs.pem, and then exports the individual certificates to individual [CA].pem files, and imports them all into a Java Keystore called client.jks

Function Convert-DodCertBundleToIndivdualCerts {
	[CmdletBinding()]
	Param (
		[Parameter(Mandatory=$true)]
		[String]
		$Path,
		[Parameter(Mandatory=$true)]
		[String]
		$Destination = "."
	)
	Begin{}
	Process{
		# Create the destination directory if it doesn't exist yet
		if (-Not (Test-Path $Destination)) {
			New-Item -Name $Destination -ItemType directory
		}

		# TODO: Can we do this without exporting the entire chain?
		Write-Host "Converting the DoD certificate bundle to PEM format..."
		$certificateBundleFile = $Destination + "\" + "DoD_CA_Bundle.pem"
		& openssl pkcs7 -in $Path -print_certs -out $certificateBundleFile
		Write-Host "DoD certificate bundle converted to PEM format and saved as DoD_CA_Bundle.pem"

		Write-Host "Identifying the individual DoD certificates..."
		$certificateBundle = Get-Content $certificateBundleFile | Out-String
		# Since -Split includes the match as a separate item, we use some regex trickery to match a zero-length section immediately after our intended match
		$certificates = $certificateBundle -Split "(?<=" + "-----END CERTIFICATE-----" + [System.Environment]::NewLine + [System.Environment]::NewLine + ")"
		Write-Host "Individual DoD certificates identified"


		Write-Host -Object $certificates #Debug
		Write-Host -Object $certificates[0] #Debug

		foreach ($certificate in $certificates) {
			# Get the name of the certificate so we can use it as a filename for the exported file
			# Get the first line, which should be the Subject=blahblahCN=[caname]
			$subjectLine = $certificate.Split([System.Environment]::NewLine)[0]
			$subject = $subjectLine.Substring($subjectLine.LastIndexOf("=") + 1)
			$certificateFile = $Destination + "/" + $subject.Trim().Replace(" ", "_") + ".pem"

			Write-Host ("Writing " + $certificateFile + "...")
			$certificate | Out-File -FilePath $certificateFile
		}
		Write-Host "Done!"
	}
	End{}
}

Export-ModuleMember -Function Convert-DodCertBundleToIndivdualCerts