From d675515bd4854e1905d27c096fa949944744b010 Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Fri, 27 Jan 2017 00:25:47 +0100 Subject: gsm48_tx_mm_auth_req(): support UMTS AUTN To be able to do R99 UMTS authentication, we need to send along AUTN bytes in the Authentication Request. Add autn parameter to gsm48_tx_mm_auth_req() and conditionally append the R99 AUTN TLV to the Authentication Request message. Change-Id: I0d644559088706aa06b42b9bfe1f8c21ca6fa4da --- openbsc/include/openbsc/gsm_04_08.h | 3 ++- openbsc/src/libmsc/gsm_04_08.c | 23 ++++++++++++++++++++--- openbsc/src/libmsc/token_auth.c | 4 ++-- 3 files changed, 24 insertions(+), 6 deletions(-) diff --git a/openbsc/include/openbsc/gsm_04_08.h b/openbsc/include/openbsc/gsm_04_08.h index fd0b89d79..cb632f632 100644 --- a/openbsc/include/openbsc/gsm_04_08.h +++ b/openbsc/include/openbsc/gsm_04_08.h @@ -53,7 +53,8 @@ int get_reason_by_chreq(uint8_t ra, int neci); void gsm_net_update_ctype(struct gsm_network *net); int gsm48_tx_mm_info(struct gsm_subscriber_connection *conn); -int gsm48_tx_mm_auth_req(struct gsm_subscriber_connection *conn, uint8_t *rand, int key_seq); +int gsm48_tx_mm_auth_req(struct gsm_subscriber_connection *conn, uint8_t *rand, + uint8_t *autn, int key_seq); int gsm48_tx_mm_auth_rej(struct gsm_subscriber_connection *conn); int gsm48_tx_mm_serv_ack(struct gsm_subscriber_connection *conn); int gsm48_tx_mm_serv_rej(struct gsm_subscriber_connection *conn, diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c index 838071006..407104ff2 100644 --- a/openbsc/src/libmsc/gsm_04_08.c +++ b/openbsc/src/libmsc/gsm_04_08.c @@ -238,7 +238,8 @@ int gsm48_secure_channel(struct gsm_subscriber_connection *conn, int key_seq, /* Then do whatever is needed ... */ if (rc == AUTH_DO_AUTH_THEN_CIPH) { /* Start authentication */ - return gsm48_tx_mm_auth_req(conn, op->atuple.vec.rand, op->atuple.key_seq); + return gsm48_tx_mm_auth_req(conn, op->atuple.vec.rand, NULL, + op->atuple.key_seq); } else if (rc == AUTH_DO_CIPH) { /* Start ciphering directly */ return gsm0808_cipher_mode(conn, net->a5_encryption, @@ -875,14 +876,24 @@ int gsm48_tx_mm_info(struct gsm_subscriber_connection *conn) return gsm48_conn_sendmsg(msg, conn, NULL); } -/* Section 9.2.2 */ -int gsm48_tx_mm_auth_req(struct gsm_subscriber_connection *conn, uint8_t *rand, int key_seq) +/*! Send an Authentication Request to MS on the given subscriber connection + * according to 3GPP/ETSI TS 24.008, Section 9.2.2. + * \param[in] conn Subscriber connection to send on. + * \param[in] rand Random challenge token to send, must be 16 bytes long. + * \param[in] autn r99: In case of UMTS mutual authentication, AUTN token to + * send; must be 16 bytes long, or pass NULL for plain GSM auth. + * \param[in] key_seq auth tuple's sequence number. + */ +int gsm48_tx_mm_auth_req(struct gsm_subscriber_connection *conn, uint8_t *rand, + uint8_t *autn, int key_seq) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 AUTH REQ"); struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); struct gsm48_auth_req *ar = (struct gsm48_auth_req *) msgb_put(msg, sizeof(*ar)); DEBUGP(DMM, "-> AUTH REQ (rand = %s)\n", osmo_hexdump(rand, 16)); + if (autn) + DEBUGP(DMM, " AUTH REQ (autn = %s)\n", osmo_hexdump(autn, 16)); msg->lchan = conn->lchan; gh->proto_discr = GSM48_PDISC_MM; @@ -891,9 +902,15 @@ int gsm48_tx_mm_auth_req(struct gsm_subscriber_connection *conn, uint8_t *rand, ar->key_seq = key_seq; /* 16 bytes RAND parameters */ + osmo_static_assert(sizeof(ar->rand) == 16, sizeof_auth_req_r99_rand); if (rand) memcpy(ar->rand, rand, 16); + + /* 16 bytes AUTN */ + if (autn) + msgb_tlv_put(msg, GSM48_IE_AUTN, 16, autn); + return gsm48_conn_sendmsg(msg, conn, NULL); } diff --git a/openbsc/src/libmsc/token_auth.c b/openbsc/src/libmsc/token_auth.c index 95fd9b345..5af1e980b 100644 --- a/openbsc/src/libmsc/token_auth.c +++ b/openbsc/src/libmsc/token_auth.c @@ -106,7 +106,7 @@ unauth: if (conn) { uint8_t auth_rand[16]; /* kick the subscriber off the network */ - gsm48_tx_mm_auth_req(conn, auth_rand, 0); + gsm48_tx_mm_auth_req(conn, auth_rand, NULL, 0); gsm48_tx_mm_auth_rej(conn); /* FIXME: close the channel early ?*/ //gsm48_send_rr_Release(lchan); @@ -143,7 +143,7 @@ static int token_sms_cb(unsigned int subsys, unsigned int signal, conn = connection_for_subscr(sms->receiver); if (conn) { /* kick the subscriber off the network */ - gsm48_tx_mm_auth_req(conn, auth_rand, 0); + gsm48_tx_mm_auth_req(conn, auth_rand, NULL, 0); gsm48_tx_mm_auth_rej(conn); /* FIXME: close the channel early ?*/ //gsm48_send_rr_Release(lchan); -- cgit v1.2.3