[keycloak-user] Keycloak Registration Flow: do not expose "Email already exists."

[Borislav Sirakov]

Hi,

My purpose is to entirely remove the "Email already exists." validation 
from the registration flow. That way I want to prevent exposing any 
information (to the other users) who is registered and who is not.

So, when the user tries to register with an existing email I want to 
redirect him to the email validation template immediately, that way I 
want to make him think that he is registered. Meanwhile keycloak must 
not create a new user or update the user profile at all, it has to skip 
these steps.

I have tried the FormActionFactory and FormAction interfaces, but just 
changing the validation and success methods doesn't seem enough. Any 
suggestions how to override the last step which actually sets the user 
into the storage and sends a verification email and instead of that just 
redirect the user to the verify email page? Is it possible?

Other suggestions, solutions how to achieve described effect (or other 
way to prevent exposing that info) are welcomed. Thank you!

Regards,
Borislav