diff options
| author | Sylvain Munaut <tnt@246tNt.com> | 2019-03-14 11:02:36 +0100 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2019-03-19 15:24:01 +0000 |
| commit | da9f37ed201be1fc12f6bbf8621fe489056d9012 (patch) | |
| tree | b205ef5712583a53ddcded15bf153ac0082680c7 /src/libvlr/vlr_auth_fsm.c | |
| parent | 31f4c1f927352a5e50348b80bb61f3c8b4cdc799 (diff) | |
libvlr: Allow 2G auth tuples to be re-used without going through AUTH
If the key_seq we get in the first messages matches the last_tuple, then
both we and the MS already know the key to use and we don't need the
AUTH REQUEST/RESPONSE cycle.
Security wise ... not so good, and so IMHO the 'auth required' option
in the MSC should always be set. But this allows to turn on ciphering on
a channel without doing any MM transaction, and so the MS doesn't turn
on the T3240 timer which allows to have a ciphered silent-call channel
that won't timeout.
Change-Id: Ief840a2ae7a0ffd2bf0bf726f209a79e3f787646
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Diffstat (limited to 'src/libvlr/vlr_auth_fsm.c')
| -rw-r--r-- | src/libvlr/vlr_auth_fsm.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/libvlr/vlr_auth_fsm.c b/src/libvlr/vlr_auth_fsm.c index ccf3660b8..60265104d 100644 --- a/src/libvlr/vlr_auth_fsm.c +++ b/src/libvlr/vlr_auth_fsm.c @@ -629,3 +629,18 @@ struct osmo_fsm_inst *auth_fsm_start(struct vlr_subscr *vsub, return fi; } + +bool auth_try_reuse_tuple(struct vlr_subscr *vsub, uint8_t key_seq) +{ + int max_reuse_count = vsub->vlr->cfg.auth_tuple_max_reuse_count; + struct vlr_auth_tuple *at = vsub->last_tuple; + + if (!at) + return false; + if ((max_reuse_count >= 0) && (at->use_count > max_reuse_count)) + return false; + if (at->key_seq != key_seq) + return false; + at->use_count++; + return true; +} |