File: rlm_wimax.c

package info (click to toggle)
freeradius 3.0.12+dfsg-5+deb9u1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 21,144 kB
  • ctags: 11,887
  • sloc: ansic: 109,067; sh: 5,176; perl: 2,648; sql: 1,397; python: 1,161; makefile: 374; xml: 62; tcl: 35; sed: 23; ruby: 22
file content (482 lines) | stat: -rw-r--r-- 13,419 bytes parent folder | download
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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
/*
 *   This program is 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 St, Fifth Floor, Boston, MA 02110-1301, USA
 */

/**
 * $Id: 784ae635e9b3ee83e1985a1e8193b4e860155f0c $
 * @file rlm_wimax.c
 * @brief Supports various WiMax functionality.
 *
 * @copyright 2008 Alan DeKok <aland@networkradius.com>
 */
RCSID("$Id: 784ae635e9b3ee83e1985a1e8193b4e860155f0c $")
USES_APPLE_DEPRECATED_API	/* OpenSSL API has been deprecated by Apple */

#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/modules.h>

/*
 *	FIXME: Add check for this header to configure.ac
 */
#include <openssl/hmac.h>

/*
 *	FIXME: Fix the build system to create definitions from names.
 */
typedef struct rlm_wimax_t {
	bool	delete_mppe_keys;
} rlm_wimax_t;

/*
 *	A mapping of configuration file names to internal variables.
 *
 *	Note that the string is dynamically allocated, so it MUST
 *	be freed.  When the configuration file parse re-reads the string,
 *	it free's the old one, and strdup's the new one, placing the pointer
 *	to the strdup'd string into 'config.string'.  This gets around
 *	buffer over-flows.
 */
static const CONF_PARSER module_config[] = {
	{ "delete_mppe_keys", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_wimax_t, delete_mppe_keys), "no" },
	CONF_PARSER_TERMINATOR
};

/*
 *	Find the named user in this modules database.  Create the set
 *	of attribute-value pairs to check and reply with for this user
 *	from the database. The authentication code only needs to check
 *	the password, the rest is done here.
 */
static rlm_rcode_t CC_HINT(nonnull) mod_authorize(UNUSED void *instance, REQUEST *request)
{
	VALUE_PAIR *vp;

	/*
	 *	Fix Calling-Station-Id.  Damn you, WiMAX!
	 */
	vp =  fr_pair_find_by_num(request->packet->vps, PW_CALLING_STATION_ID, 0, TAG_ANY);
	if (vp && (vp->vp_length == 6)) {
		int i;
		char *p;
		uint8_t buffer[6];

		memcpy(buffer, vp->vp_strvalue, 6);
		vp->vp_length = (5*3)+2;
		vp->vp_strvalue = p = talloc_array(vp, char, vp->vp_length + 1);
		vp->type = VT_DATA;

		/*
		 *	RFC 3580 Section 3.20 says this is the preferred
		 *	format.  Everyone *SANE* is using this format,
		 *	so we fix it here.
		 */
		for (i = 0; i < 6; i++) {
			fr_bin2hex(&p[i * 3], &buffer[i], 1);
			p[(i * 3) + 2] = '-';
		}

		p[(5*3)+2] = '\0';

		DEBUG2("rlm_wimax: Fixing WiMAX binary Calling-Station-Id to %s",
		       vp->vp_strvalue);
		return RLM_MODULE_OK;
	}

	return RLM_MODULE_NOOP;
}


/*
 *	Massage the request before recording it or proxying it
 */
static rlm_rcode_t CC_HINT(nonnull) mod_preacct(void *instance, REQUEST *request)
{
	return mod_authorize(instance, request);
}

/*
 *	Write accounting information to this modules database.
 */
static rlm_rcode_t CC_HINT(nonnull) mod_accounting(UNUSED void *instance, UNUSED REQUEST *request)
{
	return RLM_MODULE_OK;
}

/*
 *	Generate the keys after the user has been authenticated.
 */
static rlm_rcode_t CC_HINT(nonnull) mod_post_auth(void *instance, REQUEST *request)
{
	rlm_wimax_t *inst = instance;
	VALUE_PAIR *msk, *emsk, *vp;
	VALUE_PAIR *mn_nai, *ip, *fa_rk;
	HMAC_CTX *hmac;
	unsigned int rk1_len, rk2_len, rk_len;
	uint32_t mip_spi;
	uint8_t usage_data[24];
	uint8_t mip_rk_1[EVP_MAX_MD_SIZE], mip_rk_2[EVP_MAX_MD_SIZE];
	uint8_t mip_rk[2 * EVP_MAX_MD_SIZE];

	msk = fr_pair_find_by_num(request->reply->vps, PW_EAP_MSK, 0, TAG_ANY);
	emsk = fr_pair_find_by_num(request->reply->vps, PW_EAP_EMSK, 0, TAG_ANY);
	if (!msk || !emsk) {
		RDEBUG("No EAP-MSK or EAP-EMSK.  Cannot create WiMAX keys");
		return RLM_MODULE_NOOP;
	}

	/*
	 *	If we delete the MS-MPPE-*-Key attributes, then add in
	 *	the WiMAX-MSK so that the client has a key available.
	 */
	if (inst->delete_mppe_keys) {
		fr_pair_delete_by_num(&request->reply->vps, 16, VENDORPEC_MICROSOFT, TAG_ANY);
		fr_pair_delete_by_num(&request->reply->vps, 17, VENDORPEC_MICROSOFT, TAG_ANY);

		vp = pair_make_reply("WiMAX-MSK", NULL, T_OP_EQ);
		if (vp) {
			fr_pair_value_memcpy(vp, msk->vp_octets, msk->vp_length);
		}
	}

	/*
	 *	Initialize usage data.
	 */
	memcpy(usage_data, "miprk@wimaxforum.org", 21);	/* with trailing \0 */
	usage_data[21] = 0x02;
	usage_data[22] = 0x00;
	usage_data[23] = 0x01;

	/*
	 *	MIP-RK-1 = HMAC-SSHA256(EMSK, usage-data | 0x01)
	 */
	hmac = HMAC_CTX_new();
	HMAC_Init_ex(hmac, emsk->vp_octets, emsk->vp_length, EVP_sha256(), NULL);

	HMAC_Update(hmac, &usage_data[0], sizeof(usage_data));
	HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

	/*
	 *	MIP-RK-2 = HMAC-SSHA256(EMSK, MIP-RK-1 | usage-data | 0x01)
	 */
	HMAC_Init_ex(hmac, emsk->vp_octets, emsk->vp_length, EVP_sha256(), NULL);

	HMAC_Update(hmac, (uint8_t const *) &mip_rk_1, rk1_len);
	HMAC_Update(hmac, &usage_data[0], sizeof(usage_data));
	HMAC_Final(hmac, &mip_rk_2[0], &rk2_len);

	memcpy(mip_rk, mip_rk_1, rk1_len);
	memcpy(mip_rk + rk1_len, mip_rk_2, rk2_len);
	rk_len = rk1_len + rk2_len;

	/*
	 *	MIP-SPI = HMAC-SSHA256(MIP-RK, "SPI CMIP PMIP");
	 */
	HMAC_Init_ex(hmac, mip_rk, rk_len, EVP_sha256(), NULL);

	HMAC_Update(hmac, (uint8_t const *) "SPI CMIP PMIP", 12);
	HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

	/*
	 *	Take the 4 most significant octets.
	 *	If less than 256, add 256.
	 */
	mip_spi = ((mip_rk_1[0] << 24) | (mip_rk_1[1] << 16) |
		   (mip_rk_1[2] << 8) | mip_rk_1[3]);
	if (mip_spi < 256) mip_spi += 256;

	if (rad_debug_lvl) {
		int len = rk_len;
		char buffer[512];

		if (len > 128) len = 128; /* buffer size */

		fr_bin2hex(buffer, mip_rk, len);
		RDEBUG("MIP-RK = 0x%s", buffer);
		RDEBUG("MIP-SPI = %08x", ntohl(mip_spi));
	}

	/*
	 *	FIXME: Perform SPI collision prevention
	 */

	/*
	 *	Calculate mobility keys
	 */
	mn_nai = fr_pair_find_by_num(request->packet->vps, PW_WIMAX_MN_NAI, 0, TAG_ANY);
	if (!mn_nai) mn_nai = fr_pair_find_by_num(request->reply->vps, PW_WIMAX_MN_NAI, 0, TAG_ANY);
	if (!mn_nai) {
		RWDEBUG("WiMAX-MN-NAI was not found in the request or in the reply");
		RWDEBUG("We cannot calculate MN-HA keys");
	}

	/*
	 *	WiMAX-IP-Technology
	 */
	vp = NULL;
	if (mn_nai) vp = fr_pair_find_by_num(request->reply->vps, 23, VENDORPEC_WIMAX, TAG_ANY);
	if (!vp) {
		RWDEBUG("WiMAX-IP-Technology not found in reply");
		RWDEBUG("Not calculating MN-HA keys");
	}

	if (vp) switch (vp->vp_integer) {
	case 2:			/* PMIP4 */
		/*
		 *	Look for WiMAX-hHA-IP-MIP4
		 */
		ip = fr_pair_find_by_num(request->reply->vps, 6, VENDORPEC_WIMAX, TAG_ANY);
		if (!ip) {
			RWDEBUG("WiMAX-hHA-IP-MIP4 not found.  Cannot calculate MN-HA-PMIP4 key");
			break;
		}

		/*
		 *	MN-HA-PMIP4 =
		 *	   H(MIP-RK, "PMIP4 MN HA" | HA-IPv4 | MN-NAI);
		 */
		HMAC_Init_ex(hmac, mip_rk, rk_len, EVP_sha1(), NULL);

		HMAC_Update(hmac, (uint8_t const *) "PMIP4 MN HA", 11);
		HMAC_Update(hmac, (uint8_t const *) &ip->vp_ipaddr, 4);
		HMAC_Update(hmac, (uint8_t const *) &mn_nai->vp_strvalue, mn_nai->vp_length);
		HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

		/*
		 *	Put MN-HA-PMIP4 into WiMAX-MN-hHA-MIP4-Key
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 10, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       10, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP4-Key");
			break;
		}
		fr_pair_value_memcpy(vp, &mip_rk_1[0], rk1_len);

		/*
		 *	Put MN-HA-PMIP4-SPI into WiMAX-MN-hHA-MIP4-SPI
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 11, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       11, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP4-SPI");
			break;
		}
		vp->vp_integer = mip_spi + 1;
		break;

	case 3:			/* CMIP4 */
		/*
		 *	Look for WiMAX-hHA-IP-MIP4
		 */
		ip = fr_pair_find_by_num(request->reply->vps, 6, VENDORPEC_WIMAX, TAG_ANY);
		if (!ip) {
			RWDEBUG("WiMAX-hHA-IP-MIP4 not found.  Cannot calculate MN-HA-CMIP4 key");
			break;
		}

		/*
		 *	MN-HA-CMIP4 =
		 *	   H(MIP-RK, "CMIP4 MN HA" | HA-IPv4 | MN-NAI);
		 */
		HMAC_Init_ex(hmac, mip_rk, rk_len, EVP_sha1(), NULL);

		HMAC_Update(hmac, (uint8_t const *) "CMIP4 MN HA", 11);
		HMAC_Update(hmac, (uint8_t const *) &ip->vp_ipaddr, 4);
		HMAC_Update(hmac, (uint8_t const *) &mn_nai->vp_strvalue, mn_nai->vp_length);
		HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

		/*
		 *	Put MN-HA-CMIP4 into WiMAX-MN-hHA-MIP4-Key
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 10, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       10, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP4-Key");
			break;
		}
		fr_pair_value_memcpy(vp, &mip_rk_1[0], rk1_len);

		/*
		 *	Put MN-HA-CMIP4-SPI into WiMAX-MN-hHA-MIP4-SPI
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 11, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       11, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP4-SPI");
			break;
		}
		vp->vp_integer = mip_spi;
		break;

	case 4:			/* CMIP6 */
		/*
		 *	Look for WiMAX-hHA-IP-MIP6
		 */
		ip = fr_pair_find_by_num(request->reply->vps, 7, VENDORPEC_WIMAX, TAG_ANY);
		if (!ip) {
			RWDEBUG("WiMAX-hHA-IP-MIP6 not found.  Cannot calculate MN-HA-CMIP6 key");
			break;
		}

		/*
		 *	MN-HA-CMIP6 =
		 *	   H(MIP-RK, "CMIP6 MN HA" | HA-IPv6 | MN-NAI);
		 */
		HMAC_Init_ex(hmac, mip_rk, rk_len, EVP_sha1(), NULL);

		HMAC_Update(hmac, (uint8_t const *) "CMIP6 MN HA", 11);
		HMAC_Update(hmac, (uint8_t const *) &ip->vp_ipv6addr, 16);
		HMAC_Update(hmac, (uint8_t const *) &mn_nai->vp_strvalue, mn_nai->vp_length);
		HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

		/*
		 *	Put MN-HA-CMIP6 into WiMAX-MN-hHA-MIP6-Key
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 12, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       12, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP6-Key");
			break;
		}
		fr_pair_value_memcpy(vp, &mip_rk_1[0], rk1_len);

		/*
		 *	Put MN-HA-CMIP6-SPI into WiMAX-MN-hHA-MIP6-SPI
		 */
		vp = fr_pair_find_by_num(request->reply->vps, 13, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       13, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-MN-hHA-MIP6-SPI");
			break;
		}
		vp->vp_integer = mip_spi + 2;
		break;

	default:
		break;		/* do nothing */
	}

	/*
	 *	Generate FA-RK, if requested.
	 *
	 *	FA-RK= H(MIP-RK, "FA-RK")
	 */
	fa_rk = fr_pair_find_by_num(request->reply->vps, 14, VENDORPEC_WIMAX, TAG_ANY);
	if (fa_rk && (fa_rk->vp_length <= 1)) {
		HMAC_Init_ex(hmac, mip_rk, rk_len, EVP_sha1(), NULL);

		HMAC_Update(hmac, (uint8_t const *) "FA-RK", 5);

		HMAC_Final(hmac, &mip_rk_1[0], &rk1_len);

		fr_pair_value_memcpy(fa_rk, &mip_rk_1[0], rk1_len);
	}

	/*
	 *	Create FA-RK-SPI, which is really SPI-CMIP4, which is
	 *	really MIP-SPI.  Clear?  Of course.  This is WiMAX.
	 */
	if (fa_rk) {
		vp = fr_pair_find_by_num(request->reply->vps, 61, VENDORPEC_WIMAX, TAG_ANY);
		if (!vp) {
			vp = radius_pair_create(request->reply, &request->reply->vps,
					       61, VENDORPEC_WIMAX);
		}
		if (!vp) {
			RWDEBUG("Failed creating WiMAX-FA-RK-SPI");
		} else {
			vp->vp_integer = mip_spi;
		}
	}

	/*
	 *	Give additional information about requests && responses
	 *
	 *	WiMAX-RRQ-MN-HA-SPI
	 */
	vp = fr_pair_find_by_num(request->packet->vps, 20, VENDORPEC_WIMAX, TAG_ANY);
	if (vp) {
		RDEBUG("Client requested MN-HA key: Should use SPI to look up key from storage");
		if (!mn_nai) {
			RWDEBUG("MN-NAI was not found!");
		}

		/*
		 *	WiMAX-RRQ-HA-IP
		 */
		if (!fr_pair_find_by_num(request->packet->vps, 18, VENDORPEC_WIMAX, TAG_ANY)) {
			RWDEBUG("HA-IP was not found!");
		}


		/*
		 *	WiMAX-HA-RK-Key-Requested
		 */
		vp = fr_pair_find_by_num(request->packet->vps, 58, VENDORPEC_WIMAX, TAG_ANY);
		if (vp && (vp->vp_integer == 1)) {
			RDEBUG("Client requested HA-RK: Should use IP to look it up from storage");
		}
	}

	/*
	 *	Wipe the context of all sensitive information.
	 */
	HMAC_CTX_free(hmac);

	return RLM_MODULE_UPDATED;
}


/*
 *	The module name should be the only globally exported symbol.
 *	That is, everything else should be 'static'.
 *
 *	If the module needs to temporarily modify it's instantiation
 *	data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
 *	The server will then take care of ensuring that the module
 *	is single-threaded.
 */
extern module_t rlm_wimax;
module_t rlm_wimax = {
	.magic		= RLM_MODULE_INIT,
	.name		= "wimax",
	.type		= RLM_TYPE_THREAD_SAFE,
	.inst_size	= sizeof(rlm_wimax_t),
	.config		= module_config,
	.methods = {
		[MOD_AUTHORIZE]		= mod_authorize,
		[MOD_PREACCT]		= mod_preacct,
		[MOD_ACCOUNTING]	= mod_accounting,
		[MOD_POST_AUTH]		= mod_post_auth
	},
};