powershell could not create ssl/tsl secure

Question

I'm using a powershell script to download and execute a file, but since some time I go I get a could not create ssl/tsl secure channel.

$down = New-Object System.Net.WebClient; 
$url = 'url'; 
$file = 'file';
$down.DownloadFile($url,$file); 
$exec = New-Object -com shell.application; 
$exec.shellexecute($file); 
exit; 

Answer 1

TLS 1.2 should be enabled to get it working. In PowerShell you can find out which protocols your system supports by running this code:

[Enum]::GetNames([Net.SecurityProtocolType]) -contains 'Tls12'

If the result is True then your system supports TLS 1.2. You can find out which protocols are being used by running:

[System.Net.ServicePointManager]::SecurityProtocol.HasFlag([Net.SecurityProtocolType]::Tls12)

If the result is True then TLS 1.2 is being used . However, you can add TLS 1.2 explicitly by using:

[Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12

This should solve these problems.

Answer 2

It may be that the site you are connection to requires TLS 1.2, whereas powershell uses TLS 1.0 by default (if I remember correctly)

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
$down = New-Object System.Net.WebClient
$url = 'https://github.com/mpdairy/posh.git'
$file = 'C:\ExistingDirectory\test.git'
$down.DownloadFile($url,$file)
$exec = New-Object -com shell.application
$exec.shellexecute($file)
exit

Without using Tls 1.2, I get this error:

Exception calling "DownloadFile" with "2" argument(s): "The request was aborted: Could not create SSL/TLS
secure channel."
At line:1 char:1
+ $down.DownloadFile($url,$file)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : WebException