powershell使用ServerCertificateValidationCallback接受自签名证书

Question

I cannot seem to get this to work using Powershell 5.1. The device is a Cisco MX800 CE9.3.

$url = "https://10.1.135.20/getxml?location=/Status"
[Net.ServicePointManager]::ServerCertificateValidationCallback={$true} 
$webclient = New-Object System.Net.Webclient
$credCache = New-Object System.Net.CredentialCache
$creds = New-Object System.Net.NetworkCredential($user,$pwd)
$credCache.Add($url, "Basic", $creds)
$webclient.Credentials = $credCache
$webpage = $webclient.DownloadString($url)

Running this script using http returns XML as expected, but using https returns the error below

Exception calling "DownloadString" with "1" argument(s): "The underlying connection was closed: An unexpected error occurred on a send." + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : WebException

Answer 1

In the case above, after searching for answers, I dug in and did packet captures. One packet capture with powershell talking to the server and one packet capture with a web browser talking to the server.

The PS Client Hello was using TLS1.0

The Web browsers Client Hello was using TLS1.2

So, in PS I added this to the code and I was able to use https against the server. [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12