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authorSylvain Munaut <tnt@246tNt.com>2019-03-14 11:02:36 +0100
committerHarald Welte <laforge@gnumonks.org>2019-03-19 15:24:01 +0000
commitda9f37ed201be1fc12f6bbf8621fe489056d9012 (patch)
treeb205ef5712583a53ddcded15bf153ac0082680c7 /src/libvlr/vlr_access_req_fsm.c
parent31f4c1f927352a5e50348b80bb61f3c8b4cdc799 (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_access_req_fsm.c')
-rw-r--r--src/libvlr/vlr_access_req_fsm.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/src/libvlr/vlr_access_req_fsm.c b/src/libvlr/vlr_access_req_fsm.c
index 3b40285..26db42c 100644
--- a/src/libvlr/vlr_access_req_fsm.c
+++ b/src/libvlr/vlr_access_req_fsm.c
@@ -67,6 +67,7 @@ struct proc_arq_priv {
struct osmo_location_area_id lai;
bool authentication_required;
bool ciphering_required;
+ uint8_t key_seq;
bool is_r99;
bool is_utran;
bool implicitly_accepted_parq_by_ciphering_cmd;
@@ -316,7 +317,8 @@ static bool is_auth_required(struct proc_arq_priv *par)
/* The cases where the authentication procedure should be used
* are defined in 3GPP TS 33.102 */
/* For now we use a default value passed in to vlr_lu_fsm(). */
- return par->authentication_required || par->ciphering_required;
+ return par->authentication_required ||
+ (par->ciphering_required && !auth_try_reuse_tuple(par->vsub, par->key_seq));
}
/* after the IMSI is known */
@@ -528,6 +530,7 @@ static const struct osmo_fsm_state proc_arq_vlr_states[] = {
.out_state_mask = S(PR_ARQ_S_DONE) |
S(PR_ARQ_S_WAIT_OBTAIN_IMSI) |
S(PR_ARQ_S_WAIT_AUTH) |
+ S(PR_ARQ_S_WAIT_CIPH) |
S(PR_ARQ_S_WAIT_UPD_LOC_CHILD) |
S(PR_ARQ_S_WAIT_SUB_PRES) |
S(PR_ARQ_S_WAIT_TRACE_SUB) |
@@ -540,6 +543,7 @@ static const struct osmo_fsm_state proc_arq_vlr_states[] = {
.in_event_mask = S(PR_ARQ_E_ID_IMSI),
.out_state_mask = S(PR_ARQ_S_DONE) |
S(PR_ARQ_S_WAIT_AUTH) |
+ S(PR_ARQ_S_WAIT_CIPH) |
S(PR_ARQ_S_WAIT_UPD_LOC_CHILD) |
S(PR_ARQ_S_WAIT_SUB_PRES) |
S(PR_ARQ_S_WAIT_TRACE_SUB) |
@@ -637,6 +641,7 @@ vlr_proc_acc_req(struct osmo_fsm_inst *parent,
const struct osmo_location_area_id *lai,
bool authentication_required,
bool ciphering_required,
+ uint8_t key_seq,
bool is_r99, bool is_utran)
{
struct osmo_fsm_inst *fi;
@@ -660,6 +665,7 @@ vlr_proc_acc_req(struct osmo_fsm_inst *parent,
par->parent_event_data = parent_event_data;
par->authentication_required = authentication_required;
par->ciphering_required = ciphering_required;
+ par->key_seq = key_seq;
par->is_r99 = is_r99;
par->is_utran = is_utran;