MatchPFXCertToAppRegistration.ps1

MatchPFXCertToAppRegistration.ps1

<#
  This is some simple PowerShell that uses the authenticated Az PowerShell functions to query Entra ID for Service Principal certificates to match them to a thumbprint.
  Delete the "-Password $mypwd" if the PFX file doesn't have a password on it.
  This is convenient for when you have access to a PFX file, but don't know which App Registration uses it.
#>

# Change "$PWD\testCertificate.pfx" to point to your PFX file
$pfxThumb = ((Get-PfxData "$PWD\testCertificate.pfx" -Password $mypwd).EndEntityCertificates).Thumbprint

# Iterate through each application, find their certificates, and compare the thumbprint to yours
Get-AzADApplication | ForEach-Object{
	$appTempId = $_.AppId
	$appTempName = $_.DisplayName
	$_ | Get-AzADAppCredential | where CustomKeyIdentifier | ForEach-Object{ if([System.Convert]::ToBase64String($_.CustomKeyIdentifier) -EQ $pfxThumb){ $appTempId; $appTempName}}
}