| /* SMS based token authentication for ad-hoc GSM networks */ |
| |
| /* (C) 2009 by Harald Welte <laforge@gnumonks.org> |
| * |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <osmocom/core/talloc.h> |
| #include <openbsc/signal.h> |
| #include <openbsc/gsm_data.h> |
| #include <openbsc/gsm_04_11.h> |
| #include <openbsc/gsm_04_08.h> |
| #include <openbsc/gsm_subscriber.h> |
| #include <openbsc/chan_alloc.h> |
| #include <openbsc/db.h> |
| |
| #define TOKEN_SMS_TEXT "HAR 2009 GSM. Register at http://har2009.gnumonks.org/ " \ |
| "Your IMSI is %s, auth token is %08X, phone no is %s." |
| |
| static char *build_sms_string(struct gsm_subscriber *subscr, uint32_t token) |
| { |
| char *sms_str; |
| unsigned int len; |
| |
| len = strlen(subscr->imsi) + 8 + strlen(TOKEN_SMS_TEXT); |
| sms_str = talloc_size(tall_bsc_ctx, len); |
| if (!sms_str) |
| return NULL; |
| |
| snprintf(sms_str, len, TOKEN_SMS_TEXT, subscr->imsi, token, |
| subscr->extension); |
| sms_str[len-1] = '\0'; |
| |
| return sms_str; |
| } |
| |
| static int token_subscr_cb(unsigned int subsys, unsigned int signal, |
| void *handler_data, void *signal_data) |
| { |
| struct gsm_subscriber *subscr = signal_data; |
| struct gsm_sms *sms; |
| int rc = 0; |
| |
| if (signal != S_SUBSCR_ATTACHED) |
| return 0; |
| |
| if (subscr->net->auth_policy != GSM_AUTH_POLICY_TOKEN) |
| return 0; |
| |
| if (subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT) { |
| uint32_t token; |
| char *sms_str; |
| |
| /* we've seen this subscriber for the first time. */ |
| rc = db_subscriber_alloc_token(subscr, &token); |
| if (rc != 0) { |
| rc = -EIO; |
| goto unauth; |
| } |
| |
| sms_str = build_sms_string(subscr, token); |
| if (!sms_str) { |
| rc = -ENOMEM; |
| goto unauth; |
| } |
| |
| sms = sms_from_text(subscr, 0, sms_str); |
| talloc_free(sms_str); |
| if (!sms) { |
| rc = -ENOMEM; |
| goto unauth; |
| } |
| |
| rc = gsm411_send_sms_subscr(subscr, sms); |
| |
| /* FIXME: else, delete the subscirber from database */ |
| unauth: |
| |
| /* make sure we don't allow him in again unless he clicks the web UI */ |
| subscr->authorized = 0; |
| db_sync_subscriber(subscr); |
| if (rc) { |
| struct gsm_subscriber_connection *conn = connection_for_subscr(subscr); |
| 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_rej(conn); |
| /* FIXME: close the channel early ?*/ |
| //gsm48_send_rr_Release(lchan); |
| } |
| } |
| } |
| |
| return rc; |
| } |
| |
| static int token_sms_cb(unsigned int subsys, unsigned int signal, |
| void *handler_data, void *signal_data) |
| { |
| struct sms_signal_data *sig = signal_data; |
| struct gsm_sms *sms = sig->sms;; |
| struct gsm_subscriber_connection *conn; |
| uint8_t auth_rand[16]; |
| |
| |
| if (signal != S_SMS_DELIVERED) |
| return 0; |
| |
| |
| /* these are not the droids we've been looking for */ |
| if (!sms->receiver || |
| !(sms->receiver->flags & GSM_SUBSCRIBER_FIRST_CONTACT)) |
| return 0; |
| |
| |
| if (sms->receiver->net->auth_policy != GSM_AUTH_POLICY_TOKEN) |
| return 0; |
| |
| |
| 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_rej(conn); |
| /* FIXME: close the channel early ?*/ |
| //gsm48_send_rr_Release(lchan); |
| } |
| |
| return 0; |
| } |
| |
| //static __attribute__((constructor)) void on_dso_load_token(void) |
| void on_dso_load_token(void) |
| { |
| osmo_signal_register_handler(SS_SUBSCR, token_subscr_cb, NULL); |
| osmo_signal_register_handler(SS_SMS, token_sms_cb, NULL); |
| } |