Rather than having a 'private' structure for kc, sres and rand, we
now finally (with 4 years delay) use osmo_auth_vector from libosmogsm,
which encapsulates authentication vectors that can be either GSM
triplets or UMTS quintuples or a combination of both.
gsm_auth_tuple becomes a wrapper around osmo_auth_vector, adding
use_count and key_seq to it.
key_seq is no longer initialized inside gprs_gsup_messages.c, as there
is no CKSN / key_seq inside the message anyway. If a usre of the code
needs key_seq, they need to manage it themselves.
Make sure a new auth tuple is initialized after
db_get_lastauthtuple_for_subscr() returns an error, i.e. if no tuple is present
for the subscriber yet.
Before this patch, the first key_seq depended on the typically uninitialized
value that was present in auth tuple's key_seq upon calling
auth_get_tuple_for_subscr().
The very first key_seq used for a new subscriber will now always be 0. Before,
it used to be mostly 1 ("(0 + 1) % 7"), but depended on whether the key_seq was
indeed initialized with 0, actually by random.
In auth_get_tuple_for_subscr(), add missing condition to match incoming
key_seq with stored key_seq, so that re-authentication is requested for
mismatching key_seqs.
Add test for this issue.
Instead of using hardcoded -1 for errors, include -1 in the enum auth_action
type; apply its use.
In the mm_auth test, the string output changes from '(internal error)' to
'AUTH_ERROR', since now the proper enum value is used in auth_action_names[].
Test two situations for AUTH_DO_AUTH_THEN_CIPH:
- when no auth tuple is available
- when the key sequence from LU is marked invalid
Add convenience auth tuple comparison function using stringification.
Add basic MM Authentication test setup, with fake DB access and RAND_bytes().
So far implement simple tests for IO error during DB access and missing auth
entry.
To print the auth action during tests, add struct auth_action_names and
auth_action_str() inline function in auth.[hc].
Alexander Huemer
Harald Welte
Neels Hofmeyr