AUC: Add support for setting the AMF separation bit to '1' for EUTRAN
Despite LTE/EUTRAN using the same authentication procedure (UMTS AKA)
as 3G, there's one difference: The "operator defined" 16bit AMF field
is reduced to 15 bits, with the first bit now being used as 'separation
bit'. That bit should be '0' for 2G/3G (as it is right now) and '1'
for authentication vectores generated for authentication over
EUTRAN/EPS.
Depends: libosmocore I93850710ab55a605bf61b95063a69682a2899bb1 (OSMO_GSUP_RAT_TYPES_IE)
Change-Id: Ic766bc40f6126bb479bd0a05b0e96bec3e240008
diff --git a/src/db_auc.c b/src/db_auc.c
index e3a840e..ecb9f58 100644
--- a/src/db_auc.c
+++ b/src/db_auc.c
@@ -189,7 +189,7 @@
int db_get_auc(struct db_context *dbc, const char *imsi,
unsigned int auc_3g_ind, struct osmo_auth_vector *vec,
unsigned int num_vec, const uint8_t *rand_auts,
- const uint8_t *auts)
+ const uint8_t *auts, bool separation_bit)
{
struct osmo_sub_auth_data aud2g, aud3g;
int64_t subscr_id;
@@ -209,6 +209,12 @@
aud3g.u.umts.ind_bitlen, aud3g.u.umts.ind);
aud3g.u.umts.ind &= (1U << aud3g.u.umts.ind_bitlen) - 1;
}
+ /* the first bit (bit0) cannot be used as AMF anymore, but has been
+ * re-appropriated as the separation bit. See 3GPP TS 33.102 Annex H
+ * together with 3GPP TS 33.401 / 33.402 / 33.501 */
+ aud3g.u.umts.amf[0] = aud3g.u.umts.amf[0] & 0x7f;
+ if (separation_bit)
+ aud3g.u.umts.amf[0] |= 0x80;
LOGAUC(imsi, LOGL_DEBUG, "Calling to generate %u vectors\n", num_vec);
rc = auc_compute_vectors(vec, num_vec, &aud2g, &aud3g, rand_auts, auts);