PowerShell Installing NuGet, says unable to access internet, but I actually can

Question

I followed the steps mentioned in Using PowerShell Behind a Proxy to configure my proxy server.

netsh winhttp set proxy \"[IP]:[Port]\"
$Wcl = New-Object System.         


        

Answer 1

Try this:

[System.Net.WebRequest]::DefaultWebProxy.Credentials = System.Net.CredentialCache]::DefaultCredentials

If the above doesn't work try this:

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

Answer 2

could be TLS security related (ref: https://rnelson0.com/2018/05/17/powershell-in-a-post-tls1-1-world/)

Try this command first:

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

then try to do the update. Note: the command only affects the current session and does not persist.

You may also check what version of TLS for client is set on computer. Looks like TLS 1.0 for client is required. (ref: https://powershell.org/forums/topic/wmf-5-1-upgrade-broken-repositories/)

Michael

Answer 3

As per https://community.spiceworks.com/topic/2265662-powershell-get-download-problem

I had the same problem today...

My issue was PowerShell Gallery would not download anything on W2016 boxes:

VERBOSE: InstallPackage' - name='AzureRM.BootStrapper',
version='0.5.0',destination='C:\Users\Administrator\AppData\Local\Temp\2\1254134668'
VERBOSE: DownloadPackage' - name='AzureRM.BootStrapper',
version='0.5.0',destination='C:\Users\Administrator\AppData\Local\Temp\2\1254134668\AzureRM.BootStrapper\AzureRM.BootSt
rapper.nupkg', uri='https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0'
VERBOSE: Downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0'.
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '2' more
times
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '1' more
times
VERBOSE: An error occurred while sending the request.
VERBOSE: Retry downloading 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' for '0' more
times
VERBOSE: Downloading package 'AzureRM.BootStrapper' failed, please make sure
'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' is accessable.
WARNING: Source Location 'https://www.powershellgallery.com/api/v2/package/AzureRM.BootStrapper/0.5.0' is not valid.
PackageManagement\Install-Package : Package 'AzureRM.BootStrapper' failed to download.
At C:\Program Files\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\PSModule.psm1:1772 char:21
+ ...          $null = PackageManagement\Install-Package @PSBoundParameters
+                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ResourceUnavailable: (C:\Users\Admini...tStrapper.nupkg:String) [Install-Package], Excep
   tion
    + FullyQualifiedErrorId : PackageFailedInstallOrDownload,Microsoft.PowerShell.PackageManagement.Cmdlets.InstallPac
   kage

What helped me to find out it was TLS v1.2 was this error in Fiddler:

System.Security.Authentication.AuthenticationException A call to SSPI failed, see inner exception

From there I got this -> A call to SSPI failed, see inner exception - The Local Security Authority cannot be contacted

Then tested locally with:

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

Which worked fine!

Hopefully, that will help somebody in the future :-)

You can set it for the whole .NET framework by editing registry:

# Set strong cryptography on 64 bit .Net Framework (version 4 and above)
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord


# Set strong cryptography on 32 bit .Net Framework (version 4 and above)
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord 

This happened a few days ago on Windows Server 2016 Datacentre boxes, Win 2019 works fine still.

Commands thanks to: https://johnlouros.com/blog/enabling-strong-cryptography-for-all-dot-net-applications

Happy Azure Stacking!!!