Pass 1 parameter in oAuth to access them after redirect URI was called

Question

I have configured a oAuth 2.0 authentication flow for my Angular singlePage website:

1. User opens my Login page depending on his language: example.com/en-GB or example.com/de-DE

2. After clicking on a login Btn he get's redirected to the issuer page where he can login with his email and password.

3. The issuer page then redirects him to example.com/welcome

My problem is now, how to access the info about the user language once he got redirected from my welcome component. How do I know, if he came from en-GB od de-DE) and if I should display the english or the german version of example.com/welcome. Can I pass the parameter in the redirect URI, I tried but it didn't work?

I also tried taking the queryParam from the route in my login Component in step 1 and then put the value into a Service. That's usually how I pass data between components. But after the redirect, when the welcome component gets opened, the value is always null. I tried doing it with BehaviorSubject with a starting value of null.

Then I tried passing the value into my authConfig by using customQueryParams or customTokenParameters, but I don't know how to access these params from my welcome component once the redirect happend. They are not included in the identityClaims that I receive after the redirect.:

let authConfig: AuthConfig = {
      issuer: 'myIssuer.com',
      redirectUri: 'example.com/welcome',
      clientId: ...,
      scope: '...',
      responseType: '...',
      customQueryParams: {
        'locale': 'de_DE'
      },
      customTokenParameters: ["de-DE"],
      dummyClientSecret: ...
    };

Does anyone know the correct way to do this?

Answer 1

In OAuth2, you can use the state parameter to pass arbitrary data. The value passed here should get sent back to you verbatim.