Athentication problems on iOS when using AppAuth and Okta

Question

I have a simple iOS Swift app loosely based on the AppAuth-iOS example (https://github.com/openid/AppAuth-iOS) as well as Okta OAuth sample (https://github.com/oktadeveloper/okta-openidconnect-appauth-ios). I am not using Service Discovery nor authomatic token aquisition (i.e. not using authStateByPresentingAuthorizationRequest).

My sample works against Azure AD but does not work against Okta. I am able to log in and am authenticated and redirected back to my mobile app (AppDelegate.application()) but then the flow does not return to my OIDAuthorizationService.present() completion block.

Here is some code:

@IBAction func signInButton(_ sender: Any) {

    // select idp
    switch selectedIdentityProvider! {
    case "Azure AD":
        selectedAuthConfig = AzureAdAuthConfig()
    case "Okta":
        selectedAuthConfig = OktaAuthConfig();
    default:
        return
    }

    appAuthAuthorize(authConfig: selectedAuthConfig!)
}

func appAuthAuthorize(authConfig: AuthConfig) {
    let serviceConfiguration = OIDServiceConfiguration(
        authorizationEndpoint: NSURL(string: authConfig.authEndPoint)! as URL,
        tokenEndpoint: NSURL(string: authConfig.tokenEndPoint)! as URL)

    let request = OIDAuthorizationRequest(configuration: serviceConfiguration, clientId: authConfig.clientId, scopes: authConfig.scope, redirectURL: NSURL(string: authConfig.redirectUri)! as URL, responseType: OIDResponseTypeCode, additionalParameters: nil)

    doAppAuthAuthorization(authRequest: request)
}


func doAppAuthAuthorization(authRequest: OIDAuthorizationRequest) {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate

    appDelegate.currentAuthorizationFlow = OIDAuthorizationService.present(authRequest, presenting: self, callback: {
        (authorizationResponse, error) in
        if (authorizationResponse != nil) {
            self.authState = OIDAuthState(authorizationResponse: authorizationResponse!)
            self.logMessage(message: "Got authorization tokens. Access token: \(String(describing: self.authState?.lastAuthorizationResponse.authorizationCode))")
            self.doTokenRequest()
        } else {
            self.authState = nil
            self.logMessage(message: "Authorization error: \(String(describing: error?.localizedDescription))")
        }
    })
}

I could rewrite the code to use authStateByPresentingAuthorizationRequest() to see if it works but am a bit leery as this code works against Azure AD. Any suggestions?

Update 1 I forgot to mention that I have a working Android/Java example going against the same Okta definitions and working like a charm.

Update 2 I did rewrite the code to use authStateByPresentingAuthorizationRequest() against Okta and am getting the same result (i.e. getting stuck after redirect back to my app). I tested this against Azure AD and it works Ok.

Answer 1

Resolved. I guess the problem was that the redirect URL defined in Okta was mixed case. Android AppAuth implementation does not mind but iOS AppAuth implementation does. Changed redirect URL in Okta to lower case only, changed redirect Uri paramter passed in to lower case only and bing, all works great. Thanks @jmelberg for pointing me in this direction - by debugging resumeAuthorizationFlow(with: url) I was able to see the exact behaviour and why the call returned a False.