[Bug] Azure SDK API - IWA specific call returns 415 on MSAL but works on ADAL

[bgavrilMS]

Which Version of MSAL are you using ?
MSAL 4.22

Platform
net fwk

What authentication flow has the issue?

• Desktop / Mobile
  • Interactive
  • Integrated Windows Auth
  • Username Password
  • Device code flow (browserless)
• Web App
  • Authorization code
  • OBO
• Daemon App
  • Service to Service calls

Other? - please describe;

Is this a new or existing app?
PowerShell

Repro

POST /adfs/services/trust/2005/usernamemixed fails with

HTTP/1.1 415 Cannot process the message because the content type 'application/octet-stream' was not the expected type 'application/soap+xml; charset=utf-8'.
Content-Length: 0
Content-Type: text/html; charset=utf-8
Server: Microsoft-HTTPAPI/2.0 Microsoft-HTTPAPI/2.0
Date: Tue, 17 Nov 2020 11:10:36 GMT

This works on ADAL

Note: I have network traces but will not post them here for PII reasons.

[bgavrilMS]

P1 as this regresses ADAL functionality and is affecting users in production.

[bgavrilMS]

Root cause seems to be a missing header Content-Type: application/soap+xml but MSAL clearly sets it

microsoft-authentication-library-for-dotnet/src/client/Microsoft.Identity.Client/WsTrust/WsTrustWebRequestManager.cs

Line 69 in 1a6fc5a

wsTrustRequest,

[bgavrilMS]

Ack @henrik-me l, I'll focus on this

[bgavrilMS]

Turns out this is external and was fixed by Azure SDK