[keycloak-dev] rehash password if different algorithm?

[Bill Burke]

Hey,

Ran into something implementing a user federation example.  My user 
federation example stores passwords in plain text.  So, I wrote a plain 
text password hasher. The first time the password is validated, the 
hashing iterations don't match from the returned 
UserCredentialValueModel.  The user fed provider always returns 0 
because its plain text.  The CredentialValidation class sees that the 
hash iterations dont' match with the default realm's hashing iterations, 
so the password is rehashed.  Rehashed with the default realm 
algorithm.  There is a bug here in that the algorithm is not set to the 
realm's hashing algorithm, so, once a user is validated once, they can 
never be validated again...at least in this scenario.

The bigger question is, how do we handle this scenario where the User 
Federation Provider does not store passwords in the same format as the 
realm's password policy? The workaround is to ignore password updates 
when updateCredentialsDirectly is called.  But this seems like a hack.  
A lot of documentation would need to be in place for this.

Bill