# Keycloak behind gateway

**URL:** <https://forum.keycloak.org/t/keycloak-behind-gateway/11830>\
**Category:** Getting advice\
**Tags:** authentication\
**Created:** [November 1, 2021, 1:03pm UTC](https://forum.keycloak.org/t/keycloak-behind-gateway/11830 "2021-11-01T13:03:36Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jtyc](https://avatars.discourse-cdn.com/v4/letter/j/4af34b/32.png) [@jtyc](https://forum.keycloak.org/u/jtyc)\
**Post date:** [November 1, 2021, 1:03pm UTC](https://forum.keycloak.org/t/keycloak-behind-gateway/11830/1 "2021-11-01T13:03:36Z")

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Hello.  
I am trying to secure a web app (service) via Keycloak using authorization code flow with Keycloak behind a gateway (C#).

Right now I am in a situation, where I can obtain authorization code via browser and I can obtain JWT access token via browser and via REST API call using the authorization code flow or client credentials flow.

What I am trying to acomplish, is getting the authorization code via my gateway. So in my gateway I have an endpoint, which calls /protocol/openid-connect/auth endpoint with all needed parameters (client\_id, response\_type, state, redirect\_url). When I call this endpoint via browser, everything works just fine and I get the authorization code. When I try to call this via gateway, I use WebClient, to make a request, that downloads the HTML of the login form and display it in a browser.

Then when I click the submit button, Keycloak shows error page that says: “_We are sorry… An error occurred, please login again through your application._”

When I check log in a Keycloak console, it says: “_WARN [org.keycloak.events] (default task-25) type=LOGIN\_ERROR, realmId=myRealm, clientId=null, userId=null, ipAddress=127.0.0.1, error=invalid\_code_”

In the settings of Keycloak, I set Web Origins to “\*”.  
I tried enabling OIDC CIBA Grant, OAuth 2.0 Device Authorization Grant, but to no avail.  
The HTML code of the login form is identical whether I call it from browser or API, I did not find any encoding issues with the code.

Is my Keycloak set up incorrectly, or am I trying to do something, that is impossible to do?  
Any help is greatly appreciated.