Change required for #SharePoint Online / #ProjectOnline REST API calls when using WebRequest #PowerShell #dotnet #office365dev

Just a quick blog post to highlight a change the is required when querying Project Online / SharePoint Online REST APIs in code when using the WebRequest class. Previously the PowerShell code sample below would work and authenticate with no issues:

#add SharePoint Online DLL - update the location if required
$programFiles = [environment]::getfolderpath("programfiles")
add-type -Path $programFiles'\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.dll'

#set the environment details
$PWAInstanceURL = "https://PWAURL"
$username = "username" 
$password = "password"
$securePass = ConvertTo-SecureString $password -AsPlainText -Force

#set the Odata URL with the correct project fields needed,
$url = $PWAInstanceURL + "/_api/ProjectData/Projects()?`$Filter=ProjectType ne 7&`$Select=ProjectId,ProjectName,ProjectPercentCompleted,ProjectOwnerName"

#get all of the data from the OData URL
[Microsoft.SharePoint.Client.SharePointOnlineCredentials]$spocreds = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($username, $securePass)  
$webrequest = [System.Net.WebRequest]::Create($url)
$webrequest.Credentials = $spocreds
$webrequest.Accept = "application/json;odata=verbose"
$webrequest.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f")
$response = $webrequest.GetResponse()
$reader = New-Object System.IO.StreamReader $response.GetResponseStream()
$data = $reader.ReadToEnd()
$results = ConvertFrom-Json -InputObject $data
$results.d.results 

There has been a change in Office365 and this would now generate a 401 unauthorized error as seen below:

It is now required to use the authentication cookie, not sure if this is a permanent change or a temporary issue. Adding the line below resolves the issue:

$webrequest.Headers["Cookie"] = $spocreds.GetAuthenticationCookie($url)

#get all of the data from the OData URL
[Microsoft.SharePoint.Client.SharePointOnlineCredentials]$spocreds = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($username, $securePass)  
$webrequest = [System.Net.WebRequest]::Create($url)
$webrequest.Credentials = $spocreds
$webrequest.Accept = "application/json;odata=verbose"
$webrequest.Headers["Cookie"] = $spocreds.GetAuthenticationCookie($url)
$webrequest.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f")
$response = $webrequest.GetResponse()

This change would be applicable to all of my PowerShell code samples that query the Project Online OData API found here: https://gallery.technet.microsoft.com/site/search?f%5B0%5D.Type=User&f%5B0%5D.Value=PWMather&sortBy=Date

Hope that helps