Powershell wget protocol violation

Setting the ServerCertificateValidationCallback delegate won't help you - SSL/TLS is not the protocol being referred to - the protocol violation is with regards to the HTTP headers (eg. long after TLS has been established).

There's a .NET configuration flag called useUnsafeHeaderParsing that controls whether such violations are ignored or not.

Using reflection, it can also be set from the runtime. This Technet forum answer give's a great example of how to do so in PowerShell, we can wrap that in a nifty function like below:

function Set-UseUnsafeHeaderParsing{    param(        [Parameter(Mandatory,ParameterSetName='Enable')]        [switch]$Enable,        [Parameter(Mandatory,ParameterSetName='Disable')]        [switch]$Disable    )    $ShouldEnable = $PSCmdlet.ParameterSetName -eq 'Enable'    $netAssembly = [Reflection.Assembly]::GetAssembly([System.Net.Configuration.SettingsSection])    if($netAssembly)    {        $bindingFlags = [Reflection.BindingFlags] 'Static,GetProperty,NonPublic'        $settingsType = $netAssembly.GetType('System.Net.Configuration.SettingsSectionInternal')        $instance = $settingsType.InvokeMember('Section', $bindingFlags, $null, $null, @())        if($instance)        {            $bindingFlags = 'NonPublic','Instance'            $useUnsafeHeaderParsingField = $settingsType.GetField('useUnsafeHeaderParsing', $bindingFlags)            if($useUnsafeHeaderParsingField)            {              $useUnsafeHeaderParsingField.SetValue($instance, $ShouldEnable)            }        }    }}

And then use like:

Set-UseUnsafeHeaderParsing -Enable

before calling Invoke-WebRequest