aboutsummaryrefslogtreecommitdiffstats
path: root/openbsc/src/token_auth.c
blob: 7fefea5a4187d0fce342fc90dd23e6eaa482f305 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/* 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 General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <stdio.h>
#include <osmocore/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."

extern struct gsm_sms *sms_from_text(struct gsm_subscriber *receiver,
				     const char *text);

static char *build_sms_string(struct gsm_subscriber *subscr, u_int32_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) {
		u_int32_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, 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_lchan *lchan = lchan_for_subscr(subscr);
			if (lchan) {
				u_int8_t auth_rand[16];
				/* kick the subscriber off the network */
				gsm48_tx_mm_auth_req(lchan, auth_rand, 0);
				gsm48_tx_mm_auth_rej(lchan);
				/* 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 gsm_sms *sms = signal_data;
	struct gsm_lchan *lchan;
	u_int8_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;


	lchan = lchan_for_subscr(sms->receiver);
	if (lchan) {
		/* kick the subscriber off the network */
		gsm48_tx_mm_auth_req(lchan, auth_rand, 0);
		gsm48_tx_mm_auth_rej(lchan);
		/* 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)
{
	register_signal_handler(SS_SUBSCR, token_subscr_cb, NULL);
	register_signal_handler(SS_SMS, token_sms_cb, NULL);
}