Function to verify that a certificate by specific template exists, using powershell

gistfile1.txt

function VerifyCertificateExists($issuer, $templateName){
    #function that validates existence of required certificate.
    #input issuer and template name (wildcards will automatically be added).
    #example : VerifyCertificateExists -issuer "myCompany" -templateName "myCertTemplate"
    #MIT license - github.com/mardahl
    try {
        Write-Verbose "Verifying existence of required certificate..." -Verbose
        $certs = Get-ChildItem -Path cert:\currentuser\my | Where-Object Issuer -like "*$issuer*" -ErrorAction Stop
        $cert = $certs | Where-Object{ $_.Extensions | Where-Object{ ($_.Oid.Value -eq '1.3.6.1.4.1.311.21.7') -and ($_.Format(0) -like "*$templateName*") }} -ErrorAction Stop
        if(!$cert){throw}
        Write-Verbose "Required certificate found!" -Verbose
    } catch {
        Write-Error "Missing certificate issued with the `"$templateName`" certificate template from the issuer `"$issuer!`""
        exit 1
    }
}