osmo_hlr.py: fix auth algo mapping, properly indicate COMP128v1

So far the resources.conf says we're using XOR, but we wrongly map 'xor' to 1,
which is actually comp128v1 in enum osmo_auth_algo from libosmocore (which
osmo-hlr uses to interpret the numbers from the hlr.db).

This explains why our "xor" tests are succeeding even though libosmocore
doesn't support XOR at all: we were using comp128v1 all the while.

Fix the auth algo mapping:
- define correct mappings, copying enum osmo_auth_algo, in util.py
- add a function to get the enum value from name, in util.py
- use this in osmo_hlr.py

Change subscriber_add() API to take the algorithm string instead of a number.
The number is libosmocore internal and we should not expose it within our API
beyond above dict. There are no callers using this parameter yet anyway.

Adjust resources.conf to indicate COMP128v1 which we are actually using and
which means we're still using algorithm number 1 after this change.

BTW, osmo-nitb uses the ctrl interface which interprets the names, so is not
vulnerable to mapping wrong numbers and needs no fix. (If osmo-hlr featured
similar CTRL, which it doesn't yet, this code could be more robust.)

Related: OS#2758
Change-Id: I7a6ce92468a6ae46136ad4f62381da261fd196c8
4 files changed