Question

I need to iterate all authentication modes for an IIS Application and disable all except one.

something like:

foreach($itm in [collection of authentication modes for app]){
if([certain authentication]){enabled = true}else{enabled = false}}

I’m familiar with Set-WebConfigurationProperty.

Answer 1

You can iterate all native (as well as any installed third-party) authentication modes for the root web application for a given site by calling Get-WebConfiguration:

$siteName = "MySiteName"

$authentications = Get-WebConfiguration `
                   -filter "system.webServer/security/authentication/*" `
                   -PSPath "IIS:\Sites\$siteName"

You can also iterate the authentication modes for any given web application in the site (or even specific file(s)). The following retrieves the authentication modes for a contrived web application called “\foo”:

$authentications = Get-WebConfiguration `
                   -filter "system.webServer/security/authentication/*" `
                   -PSPath "IIS:\Sites\$siteName\foo"

The SectionPath property can be used to examine the authentication mode, e.g.:

$authentications | foreach {$_.SectionPath}

Which outputs:

 /system.webServer/security/authentication/digestAuthentication
 /system.webServer/security/authentication/anonymousAuthentication
 /system.webServer/security/authentication/iisClientCertificateMappingAuthentication
 /system.webServer/security/authentication/basicAuthentication
 /system.webServer/security/authentication/clientCertificateMappingAuthentication
 /system.webServer/security/authentication/windowsAuthentication

You might think you could do something as simple as this in your foreach loop…

 $authentications | `
 foreach { $_.Enabled = $_.SectionPath.EndsWith('\windowsAuthentication') }

…but there’s a problem. It doesn’t work. It won’t actually fail with an error, but it won’t change anything either.

That’s because authentication sections are locked. To change a setting in a locked section, you need to call Set-WebConfigurationProperty and include the -Location parameter, e.g.,

Set-WebConfigurationProperty `
-filter "/system.webServer/security/authentication/windowsAuthentication" `
-name enabled -value true -PSPath "IIS:\" -location $siteName

I suppose you can still pipe the objects to the foreach-object cmdlet but it’s probably going to be a lot easier to read (and maintain) if you script this using a foreach loop.

$siteName = "MySiteName"

$authentications = Get-WebConfiguration `
                   -filter "system.webServer/security/authentication/*" `
                   -PSPath "IIS:\Sites\$siteName"

foreach ($auth in $authentications)
{
     $auth.SectionPath -match "/windowsAuthentication$"
     $enable = ($matches.count -gt 0)

     Set-WebConfigurationProperty `
     -filter $auth.SectionPath `
     -name enabled -value $enable -PSPath "IIS:\" -location $siteName
}