How to code this powershell script?

Question

Referring to following powershell coding, I would like to know on why it fails to download Excel File

    $clnt = new-object System.Net.WebClient
    $url = "https://www.cmegroup.com/CmeWS/exp/voiProductsViewExport.ctl?media=xls&tradeDate=20220107&assetClassId=3&reportType=F&excluded=CEE,CEU,KCB"
    $file = "C:\sample.xls"
    try {
        $request = [System.Net.WebRequest]::Create($url)
        $request.Method = 'HEAD'
        $response = $request.GetResponse()
        $httpStatus = $response.StatusCode
        $urlIsValid = ($httpStatus -eq 'OK')
        $tryError = $null
        $response.Close()

        $clnt.DownloadFile($url,$file)

    }
    catch [System.Exception] {
        $httpStatus = $null
        $tryError = $_.Exception
        $urlIsValid = $false;
        Write-Host "There was an error downloading $file" 
        $j++
    }

Does anyone have any suggestions?
Thanks in advance

Answer 1

It's possible (probable, actually) that the site no longer uses the defunct TLS version your code is trying to use.

Add this to your code before contacting the web site:

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

Another problem may be that the site is using a self-signed certificate, an expired certificate, or a certificate that's not in your machines trusted sites list.

Answer 2

I would like to know on why it fails

For starters,, you have to display the error exception when you catch an error. Forum users would have no way of knowing what error your site is returning to you.

 Write-Host "There was an error downloading $file" 
 Write-Host $tryError 

Second, I would not try to write to the C;\ root. The default permissions require you to run the process as an administrator. Better to use a download folder and set the proper permissions.

 $file = "C:\Downloads\sample.xls"

Finally, why are doing a HEAD request first? Are you testing to see if the site is alive? Just try the download, if the site isn't accessible, you'll get the same error.

Why don't you just use Invoke-WebRequest?

Invoke-WebRequest -Uri $url -OutFile $file

https://lazyadmin.nl/powershell/download-file-powershell/

Answer 3

When I run following coding, it shows below error
Do you have any suggestions on what problem is?
Thank you very much for any suggestions (^v^)

$clnt = new-object System.Net.WebClient
$url = "https://www.cmegroup.com/CmeWS/exp/voiProductsViewExport.ctl?media=xls&tradeDate=20220107&assetClassId=3&reportType=F&excluded=CEE,CEU,KCB"
$file = "D:\sample.xls"
Invoke-WebRequest -Uri $url -OutFile $file

Invoke-WebRequest : The request was aborted: Could not create SSL/TLS secure channel.
Locate Line:1 word:1

• Invoke-WebRequest -Uri $url -OutFile $file
• ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
• CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest]，WebExce
  ption
• FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

Answer 4

Try running the script found at this URL: checking-ssl-and-tls-versions-with-powershell.html

At least you'll know if the site accepts any of the security protocols your machine is using. Pick the most recent supported version to use.