[SR-Users] Authentication Feature Question

Hi I do have 3 Kamailio servers, one for mobile phone registrations, one for softphone registrations and one for SIP device registrations. Each of those devices connects to it's perspective kamailio server sip1.domain.com sip2.domain.com sip3.domain.com All 3 Kamailio servers share the same database, and users can use their kamailio user/pwd on any of the devices, now I want to use encrypted passwords and remove clear text passwords from the database. I did test with one server and all is fine,however if a user want to register from the second kamailio server it does not work, basically because the db domain entry from which the hash is created is sip1.domain.com and stored in the db, while the user connects from to sip2.domain.com this eventually generates a different hash. Is there anyway to overcome this ? Can I exclude Domain from Hash generation ? Any other option that allows me to do the above ? Thanks