[Users] Aliases and attempts from UA's to register their aliases

[Andreas Sikkema]

Hi,

I'm working on extending my OpenSER configuration to allow 
a user account to have one or more aliases.

User A is reachable by calling A, but also using alias B or 
C. I have this working for calls to the UA, but I'm having 
problems with registration attempts from A and calls from 
A to other UA's or PSTN where it wants to send B or C as 
outgoing CLI.

For some reason, all UAs I've seen so far need to register 
their aliases to be able to send an alias as outgoing CLI. 
My OpenSER config uses the following to check authenticate 
the user (from an old SER example:

if (!www_authorize("domain", "subscriber"))
{
	www_challenge("domain", "0");
	exit;
}

if (!check_to())
{
	log("LOG: To Cheating attempt\n");
	sl_send_reply("403", "That is ugly -- use To=id in REGISTERs");
	exit;
};

When a UA tries to register an alias the www_authorize() 
succeeds, because the UA sends the correct authentication 
data for A, but uses the alias B or C in the To and From 
headers so check_to() fails with the error that B or C is 
being spoofed.

I (OpenSER) know that B and C are aliases of A, but how do I 
make this registration logic accept that and send a 200 OK message 
back? (I also don't want to save the registered alias in the 
location table, but that part I know how to do, I think).

The calls using outgoing CLI of the alias have I think the same 
problem where the From header has an alias where check_from() 
expects the data for A. I think the solution for this would be 
something comparable to solving the registration problem, correct?

Thanks!

-- 
Andreas Sikkema