Get thumbprint of invalid SSL cert using old powershell

Get thumbprint of invalid SSL cert using old powershell.ps1

$myUrl = "https://my-url-with-invalid-cert"

Function Get-SSLThumbprint {
	param(
	[Parameter(
		Position=0,
		Mandatory=$true,
		ValueFromPipeline=$true,
		ValueFromPipelineByPropertyName=$true)
	]
	[Alias('FullName')]
	[String]$URL
	)

	add-type @"
		using System.Net;
		using System.Security.Cryptography.X509Certificates;
			public class IDontCarePolicy : ICertificatePolicy {
			public IDontCarePolicy() {}
			public bool CheckValidationResult(
				ServicePoint sPoint, X509Certificate cert,
				WebRequest wRequest, int certProb) {
				return true;
			}
		}
	"@

	[System.Net.ServicePointManager]::CertificatePolicy = new-object IDontCarePolicy

	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

	# Need to connect using simple GET operation for this to work
	Invoke-RestMethod -Uri $URL -Method Get | Out-Null

	$ENDPOINT_REQUEST = [System.Net.Webrequest]::Create("$URL")
	$SSL_THUMBPRINT = $ENDPOINT_REQUEST.ServicePoint.Certificate.GetCertHashString()

	return $SSL_THUMBPRINT -replace '(..(?!$))','$1:'
}

# Example output
Get-SSLThumbprint $myUrl