[keycloak-user] How to return custom error messages from custom spnego authenticator?

[Dominik Guhr]

Hi everyone,

So I just posted this question on SO, hoping to reach more people, but 
would be great to get an answer here too, obviously:

https://stackoverflow.com/questions/50695959/how-do-i-return-custom-error-messages-to-frontend-in-custom-spnego-authenticator

Thanks!

Best regards,
Dominik