Download files from dev.sitecore.net from the commandline - see https://blog.jermdavis.dev/posts/2017/downloading-stuff-from-dev-sitecore-net for info

DownloadFromSitecore.ps1

param(
    [Parameter(Mandatory=$true)]
    [string]$url,
    [Parameter(Mandatory=$true)]
    [string]$target
)

function Fetch-WebsiteCredentials
{
    $file = "dev.creds.xml"

    if(Test-Path ".\\$file")
    {
        $cred = Import-Clixml ".\\$file"
    }
    else
    {
        $cred = Get-Credential -Message "Enter your SDN download credentials:"
        $cred | Export-Clixml ".\\$file"
    }

    return $cred
}

function Fetch-DownloadAuthentication($cred)
{
    $authUrl = "https://dev.sitecore.net/api/authorization"

    $pwd = $cred.GetNetworkCredential().Password

    $postParams = "{ ""username"":""$($cred.UserName)"", ""password"":""$pwd"" }"

    $authResponse = Invoke-WebRequest -Uri $authUrl -Method Post -ContentType "application/json;charset=UTF-8" -Body $postParams -SessionVariable webSession
    $authCookies = $webSession.Cookies.GetCookies("https://sitecore.net")

    $marketPlaceCookie = $authCookies["marketplace_login"]

    if([String]::IsNullOrWhiteSpace($marketPlaceCookie))
    {
        throw "Credentials appear invalid"
    }

    $devUrl = "https://dev.sitecore.net"

    $devResponse = Invoke-WebRequest -Uri $devUrl -WebSession $webSession
    $devCookies = $webSession.Cookies.GetCookies("https://dev.sitecore.net")

    $sessionCookie = $devCookies["ASP.Net_SessionId"]

    return "$marketPlaceCookie; $sessionCookie"
}

function Invoke-FileDownload
{
    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]
        [string] $Uri,

        [Parameter(Mandatory)]
        [string] $OutputFile,

        [string] $cookies
    )

    $webClient = New-Object System.Net.WebClient

    if(!([String]::IsNullOrWhiteSpace($cookies)))
    {
        $webClient.Headers.Add([System.Net.HttpRequestHeader]::Cookie, $cookie)
    }

    $data = New-Object psobject -Property @{Uri = $Uri; OutputFile = $OutputFile}

    $changed = Register-ObjectEvent -InputObject $webClient -EventName DownloadProgressChanged -MessageData $data -Action {
        Write-Progress -Activity "Downloading $($event.MessageData.Uri)" -Status "To $($event.MessageData.OutputFile)" -PercentComplete $eventArgs.ProgressPercentage
    }

    try
    {
        $handle = $webClient.DownloadFileAsync($Uri, $PSCmdlet.GetUnresolvedProviderPathFromPSPath($OutputFile))

        while ($webClient.IsBusy)
        {
            Start-Sleep -Milliseconds 10
        }
    }
    finally
    {
        Write-Progress -Activity "Downloading $Uri" -Completed

        Remove-Job $changed -Force
        Get-EventSubscriber | Where SourceObject -eq $webClient | Unregister-Event -Force
    }    
}

$cred = Fetch-WebsiteCredentials
$cookie = Fetch-DownloadAuthentication $cred

Invoke-FileDownload -Uri $url -OutputFile $target -Cookies $cookie