Get-MultiSANCertificate.ps1

$Inf = @"
[NewRequest]
Subject="CN=adfs.infra.private,O=Local,OU=IT,C=US"
KeySpec = 1
KeyLength = 2048
HashAlgorithm = SHA256
Exportable = TRUE
MachineKeySet = TRUE
SMIME = False
PrivateKeyArchive = FALSE
UserProtected = FALSE
UseExistingKeySet = FALSE
ProviderName = "Microsoft RSA SChannel Cryptographic Provider"
ProviderType = 12
RequestType = PKCS10
KeyUsage = 0xa0
Silent = True
FriendlyName = "ADFS Farm Certificate"

[Extensions]
2.5.29.17 = "{text}"
_continue_ = "DNS=adfs.infra.private&"
_continue_ = "DNS=adfs1.infra.private&"
_continue_ = "DNS=adfs2.infra.private&"

[EnhancedKeyUsageExtension]
OID=1.3.6.1.5.5.7.3.1


"@

$InfFile = Join-Path -Path $env:TEMP -ChildPath 'request.inf'
$Inf | Out-File -FilePath $InfFile -Force
Write-Verbose -Message ('Exported Inf file to {0}...' -f $InfFile)

$CsrFile = Join-Path -Path $env:TEMP -ChildPath 'request.csr'
$Cmd = 'certreq.exe'
$Arg = ('-new -f "{0}" "{1}"' -f $InfFile, $CsrFile)
Start-Process -FilePath $Cmd -ArgumentList $Arg -Wait
Write-Host ('Executed : {0} {1}' -f $Cmd, $Arg)

$CerFile = Join-Path -Path $env:TEMP -ChildPath 'request.cer'
$Arg = ('-submit -f -attrib "CertificateTemplate:WebServer" "{0}" "{1}"' -f $CsrFile, $CerFile)
Start-Process -FilePath $Cmd -ArgumentList $Arg -Wait
Write-Host ('Executed : {0} {1}' -f $Cmd, $Arg)