Using this procedure, the VLR/SGSN can set the cs/ps purged
flag for the subscriber. We might not even need to store this
persistent in the database according to spec, but let's do it anyway, at
least until it turns out to be a performance issue.
The database stores the key material as hex-ascii, we thus need to go
through osmo_hexparse() when reading. We could also store the material
as BLOB in the database. That would however complicate matters, as it
would basically mean using the sqlite3 command to manually
inspect/modify data from the console would no longer be easily possible.
Using this commit I have 2G authentication working against osmo-sgsn
with GSUP and 'auth policy remote'.
We also introduce a 'gsup_router' which enables us to route
a transaction to a given VLR. It works based on the SERIAL attribute
communicated at time of the IPA multiplex setup as part of the CCM
SQLite has this crappy type system where you can put a string into
a boolean or integer column, which of course will break once you try to
read it as bool..
Also, add an index by IMSI to the SUBSCRIBER table.