A5 support for RSL and 04.08 (not used yet)
This just adds the 04.08 and RSL bits for A5, but not the logic
for performing authentication.
The caller would first set lchan->encr and then call
gsm48_send_rr_ciph_mode(lchan), which encapsulates the 04.08
CIPHERING MODE COMMAND into a RSL ENCRYPTION COMMAND and sends it
to the BTS for execution + forwarding.
diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index eeabc0f..30c2db3 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -1672,6 +1672,10 @@
case GSM48_MT_RR_APP_INFO:
rc = gsm48_rx_rr_app_info(msg);
break;
+ case GSM48_MT_RR_CIPH_M_COMPL:
+ DEBUGP(DRR, "CIPHERING MODE COMPLETE\n");
+ /* FIXME: check for MI (if any) */
+ break;
default:
fprintf(stderr, "Unimplemented GSM 04.08 RR msg type 0x%02x\n",
gh->msg_type);
@@ -1681,6 +1685,29 @@
return rc;
}
+/* Chapter 9.1.9: Ciphering Mode Command */
+int gsm48_send_rr_ciph_mode(struct gsm_lchan *lchan)
+{
+ struct msgb *msg = gsm48_msgb_alloc();
+ struct gsm48_hdr *gh;
+ u_int8_t ciph_mod_set;
+
+ msg->lchan = lchan;
+
+ DEBUGP(DRR, "TX CIPHERING MODE CMD\n");
+
+ if (lchan->encr.alg_id <= RSL_ENC_ALG_A5(0))
+ ciph_mod_set = 0;
+ else
+ ciph_mod_set = (lchan->encr.alg_id-1)<<1 | 1;
+
+ gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
+ gh->proto_discr = GSM48_PDISC_RR;
+ gh->msg_type = GSM48_MT_RR_CIPH_M_CMD;
+ gh->data[0] = 0x10 | (ciph_mod_set & 0xf);
+
+ return rsl_encryption_cmd(msg);
+}
int gsm48_send_rr_app_info(struct gsm_lchan *lchan, u_int8_t apdu_id,
u_int8_t apdu_len, u_int8_t *apdu)