OAuth2 Workflow - oauth2-redirect.html not found

[Derich367]

During Implementing an OAuth2 Workflow for the api documentation i'm getting the issue that the redirect page can't be found.
E.g. for local running function http://localhost:7071/oauth2-redirect.html can't be found (404) after successful authentication.

My OpenApiOAuthSecurityFlows looks like this:

class TestOAuth2 : OpenApiOAuthSecurityFlows
    {
        public TestOAuth2 ()
        {
            this.Implicit = new OpenApiOAuthFlow()
            {
                AuthorizationUrl = new Uri("https://xxxx.b2clogin.com/xxxx.onmicrosoft.com/oauth2/v2.0/authorize?p=workflow_id"),
                Scopes = { { "https://xxxx.onmicrosoft.com/xxxx-xxx/API.User", "API Access" } },
                TokenUrl = new Uri("https://xxxx.b2clogin.com/xxxx.onmicrosoft.com/oauth2/v2.0/token?p=workflow_id")
                
            };
        }
    }

Am i missing some configuration for the redirect page?

[disambiguationuk]

Sure it's not http://localhost:7071/api/* ?

[Derich367]

Sure it's not http://localhost:7071/api/* ?

Yes, swagger docs are hosted under default settings at http://localhost:7071/api/swagger/ui
But the authorization url opened by swagger contains http://localhost:7071/oauth2-redirect.html as redirect url.

[justinyoo]

@Derich367 Can I ask the steps to repro this issue on my end?

If you change this URL, http://localhost:7071/oauth2-redirect.html, to http://localhost:7071/api/oauth2-redirect.html (adding the /api segment), would it be working?

If you use the default settings, the host.json has the /api as a prefix of all endpoints - meaning, your other endpoints including oauth2-redirect.html should be the same because it's in the same instance.

[Derich367]

@justinyoo Yes, i created a demo project to reproduce this:
azure-functions-openapi-oauth2-test (Empty Function App with openapi extension and oauth2 worklflow)
The redirect Url in the generated AuthorizationUrl is http://localhost:7071/oauth2-redirect.html.
But both http://localhost:7071/oauth2-redirect.html and http://localhost:7071/api/oauth2-redirect.html returning 404.

[justinyoo]

@Derich367 I saw your sample repo.

But I don't see any endpoint pointing to either /oauth2-redirect.html or /api/oauth2-redirect.html. Have you implemented the endpoint within your Function app? It's something you should implement at your end.

public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "oauth2-redirect.html")] HttpRequest req,
    ILogger log)
{
    ...

    return new ContentResult() { Content = "something", ContentType = "text/html" };
}

Alternatively, you can use proxies.json to redirect to your designated endpoint for further processing.

[Derich367]

What is then the file oauth2-redirect.html in this repo for? I thought the OAuthToken Retreive and Store-Handling is Part of this Extension.

[justinyoo]

OH! Is that mine? 🙈🙈🙈 I should implement it then. I totally overlooked that part. Thanks for letting me know!

[svrooij]

And just a quick work-around for anyone who is struggling with this, just add a proxies.json file with the following content

{
  "$schema": "http://json.schemastore.org/proxies",
  "proxies": {
    "SwaggerUiRedirect": {
      "matchCondition": {
        "methods": [ "GET" ],
        "route": "/oauth2-redirect.html"
      },
       //I'm not sure if this url is allowed, but you get the point.
      "backendUri": "https://petstore.swagger.io/oauth2-redirect.html"
    }
  }
}