(PowerShell) HTTP - Verify Server is a Trusted Root CA

Demonstrates how to only allow connections to an HTTP server having a certificate with a root that is in our list of trusted CA root certificates.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# Starting in v9.5.0.49, all Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
$chilkatGlob = New-Object Chilkat.Global
$success = $chilkatGlob.UnlockBundle("Anything for 30-day trial.")
if ($success -ne $true) {
    $($chilkatGlob.LastErrorText)
    exit
}

#  On my particular system, the root CA cert for this URL is not pre-installed.
#  Note: This may be different for you.
#  Also, this example was written on 29-May-2015.  This URL was valid at the time,
#  but may not be valid at a future date.
$url = "https://animals.nationalgeographic.com/animals/invertebrates/starfish/"

$http = New-Object Chilkat.Http

#  Require that the SSL/TLS server certificate is not expired,
#  and that the certificate signature is valid.
#  This does not ensure that it has a chain of authentication to
#  a trusted root.  To ensure that, the TrustedRoots object (below) is required.
$http.RequireSslCertVerify = $true

#  Do the HTTPS page fetch (through the SSH tunnel)
$html = $http.QuickGetStr($url)
if ($http.LastMethodSuccess -ne $true) {
    $($http.LastErrorText)
    exit
}

$("The HTTP GET was successful.")

#  Now let's require that HTTP requests to SSL/TLS servers that don't have trusted CA roots
#  should fail.
$trustedRoots = New-Object Chilkat.TrustedRoots

#  Indicate that we will trust any pre-installed certificates on this system.
#  (The meaning of pre-installed certificates depends on the operating system, and in
#  some environments there is no such thing as pre-installed certificates.  See the reference
#  documentation for the TrustedRoots class.)
$trustedRoots.TrustSystemCaRoots = $true

#  Activate the trusted roots globally for all Chilkat objects.
#  This call really shouldn't fail, so we're not checking the return value.
$success = $trustedRoots.Activate()

#  Given that our previous HTTP GET likely kept the connection open,
#  make sure that all HTTP connections are closed before re-trying.
#  Otherwise, we'll simply be re-using the pre-existing connection.
$success = $http.CloseAllConnections()

#  Now let's try fetching the URL again.  It should fail this time because
#  there is a requirement that the SSL/TLS server certificate must have a trusted root,
#  and the trusted root for this URL is not installed on my system (but may be different for you..)
$html = $http.QuickGetStr($url)
if ($http.LastMethodSuccess -ne $true) {
    $($http.LastErrorText)
    $("Good, the HTTP request failed as expected.")
}
else {
    $($http.LastErrorText)
    $("Hmmm... we did not fail as expected?")
}