Associate KeyVault Certificate to Application Gateway for TLS Termination in Azure

#Creates or updates the policy for a certificate in a key vault.

$Policy = New-AzKeyVaultCertificatePolicy -SecretContentType "application/x-pkcs12" -SubjectName "CN=adven.com" -IssuerName "Self" -ValidityInMonths 6 -ReuseKeyOnRenewal

#Adds a certificate to a key vault.
 #Here TestCert01 is Certificate Name and hpvault01 is keyVault Name in  
Add-AzKeyVaultCertificate -VaultName "hpvault01" -Name "TestCert01" -CertificatePolicy $Policy

# Gets the status of a certificate operation. Check the progress until its status is complete
$progress=(Get-AzKeyVaultCertificateOperation -VaultName "hpvault01" -name TestCert01).status
# Gets the secrets in a key vault.
$cert=Get-AzkeyvaultSecret -VaultName "hpvault01" -Name "TestCert01"

#Converts the specified string, which encodes binary data as base-64 digits, to an equivalent 8-bit unsigned integer array

$certBytes=[System.Convert]::FromBase64String($cert.SecretValueText)

# Write all Bytes to local computer C:\xfer Folder
[System.IO.File]::WriteAllBytes("C:\xfer\TestCert01",$certBytes)

$certCollection = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2Collection

$certCollection.Import($certBytes,$null,[System.Security.Cryptography.X509Certificates.X509KeyStorageFlags]::Exportable)

$certificateBytes = $certCollection.Export([System.Security.Cryptography.X509Certificates.X509ContentType]::Cert)

$name = $cert.Name
$cerName = $name.Replace('pfx','cer')

[System.IO.File]::WriteAllBytes("C:\xfer\$cerName", $certificateBytes)
Write-Host "Certificate created from Pfx and copied to local directory C:\xfer folder

Create an Application gateway using portal

Create a Managed identity using AZ CLI
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$rgname = "newrakeshrg"
$location = "East US"
$kv = "hpvault01"
$appgwName = "prestigeappgateway"

$resourceGroup = New-AzResourceGroup -Name $rgname -Location $location
$identity = New-AzUserAssignedIdentity -Name "appgwKeyVaultIdentity" `
  -Location $location -ResourceGroupName $rgname

# Now associate the keyvault Certificate to Application gateway listener using portal