Azure AD Ms Identity callback URL (error AADSTS50011) - oauth

Question

I'm integrating Azure AD and MS-Identity on a web app with Angular.
It works on my machine, but when I deploy it, I get an issue with the callback URL.
First, to make sure the callback URL is ok, I extract it from the microsoft login popup window's URL:
Then, I url decode the content. The URL seems fine and it is available in my Azure app's redirect URL.
Then I login to Microsoft normally and I get this error (AADSTS50011):
Then I inspect the URL again (inside the query string from the urldecoded popup window's URL) and now the URL seems to have been "tampered with".
It's now something like this:
http://somedomain:80/some_page/somequerystring
instead of
https://somedomain/some_page/somequerystring
so I wonder if it's part of the problem or if it's normal behavior.
It is also mentionned "If you contact your administrator, send this info to them." I suppose I'm the "administrator" so what can I do with that "Copy info to clipboard" info to investigate the problem?

Answer 1

Is your application hosting on http (80) or https (443)? If your app service is terminating your TLS connection and handling that for you instead of your app, your sign-on will construct the redirect using the http request scheme. I hooked into the OnRedirectToIdentityProvider event to correct the scheme.
services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
.AddMicrosoftIdentityWebApp(options =>
{
Configuration.Bind("AzureAd", options);
options.Events ??= new OpenIdConnectEvents();
options.Events.OnRedirectToIdentityProvider += _fixRedirect;
});
...
private async Task _fixRedirect(RedirectContext context)
{
context.Request.Scheme = "https";
if(!context.ProtocolMessage.RedirectUri.StartsWith("https"))
context.ProtocolMessage.RedirectUri =
context.ProtocolMessage.RedirectUri.Replace("http", "https");
await Task.CompletedTask;
}