Added limiting encoding of IKEv1 SA payloads
[strongswan.git] / src / libcharon / encoding / payloads / sa_payload.c
1 /*
2 * Copyright (C) 2005-2010 Martin Willi
3 * Copyright (C) 2005 Jan Hutter
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 #include <stddef.h>
18
19 #include "sa_payload.h"
20
21 #include <encoding/payloads/encodings.h>
22 #include <utils/linked_list.h>
23 #include <daemon.h>
24
25 /* IKEv1 situation */
26 #define SIT_IDENTITY_ONLY 1
27
28 typedef struct private_sa_payload_t private_sa_payload_t;
29
30 /**
31 * Private data of an sa_payload_t object.
32 */
33 struct private_sa_payload_t {
34
35 /**
36 * Public sa_payload_t interface.
37 */
38 sa_payload_t public;
39
40 /**
41 * Next payload type.
42 */
43 u_int8_t next_payload;
44
45 /**
46 * Critical flag.
47 */
48 bool critical;
49
50 /**
51 * Reserved bits
52 */
53 bool reserved[8];
54
55 /**
56 * Length of this payload.
57 */
58 u_int16_t payload_length;
59
60 /**
61 * Proposals in this payload are stored in a linked_list_t.
62 */
63 linked_list_t *proposals;
64
65 /**
66 * Type of this payload, V1 or V2
67 */
68 payload_type_t type;
69
70 /**
71 * IKEv1 DOI
72 */
73 u_int32_t doi;
74
75 /**
76 * IKEv1 situation
77 */
78 u_int32_t situation;
79 };
80
81 /**
82 * Encoding rules for IKEv1 SA payload
83 */
84 static encoding_rule_t encodings_v1[] = {
85 /* 1 Byte next payload type, stored in the field next_payload */
86 { U_INT_8, offsetof(private_sa_payload_t, next_payload) },
87 /* 8 reserved bits */
88 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[0]) },
89 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[1]) },
90 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[2]) },
91 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[3]) },
92 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[4]) },
93 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[5]) },
94 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[6]) },
95 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[7]) },
96 /* Length of the whole SA payload*/
97 { PAYLOAD_LENGTH, offsetof(private_sa_payload_t, payload_length) },
98 /* DOI*/
99 { U_INT_32, offsetof(private_sa_payload_t, doi) },
100 /* Situation*/
101 { U_INT_32, offsetof(private_sa_payload_t, situation) },
102 /* Proposals are stored in a proposal substructure,
103 offset points to a linked_list_t pointer */
104 { PROPOSALS_V1, offsetof(private_sa_payload_t, proposals) },
105 };
106
107 /*
108 1 2 3
109 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
110 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
111 ! Next Payload ! RESERVED ! Payload Length !
112 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
113 ! DOI !
114 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
115 ! Situation !
116 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
117 ! !
118 ~ <Proposals> ~
119 ! !
120 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 */
122
123 /**
124 * Encoding rules for IKEv2 SA payload
125 */
126 static encoding_rule_t encodings_v2[] = {
127 /* 1 Byte next payload type, stored in the field next_payload */
128 { U_INT_8, offsetof(private_sa_payload_t, next_payload) },
129 /* the critical bit */
130 { FLAG, offsetof(private_sa_payload_t, critical) },
131 /* 7 Bit reserved bits */
132 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[0]) },
133 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[1]) },
134 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[2]) },
135 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[3]) },
136 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[4]) },
137 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[5]) },
138 { RESERVED_BIT, offsetof(private_sa_payload_t, reserved[6]) },
139 /* Length of the whole SA payload*/
140 { PAYLOAD_LENGTH, offsetof(private_sa_payload_t, payload_length) },
141 /* Proposals are stored in a proposal substructure,
142 offset points to a linked_list_t pointer */
143 { PROPOSALS, offsetof(private_sa_payload_t, proposals) },
144 };
145
146 /*
147 1 2 3
148 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
150 ! Next Payload !C! RESERVED ! Payload Length !
151 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
152 ! !
153 ~ <Proposals> ~
154 ! !
155 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
156 */
157
158 METHOD(payload_t, verify, status_t,
159 private_sa_payload_t *this)
160 {
161 int expected_number = 0, current_number;
162 status_t status = SUCCESS;
163 enumerator_t *enumerator;
164 proposal_substructure_t *substruct;
165
166 if (this->type == SECURITY_ASSOCIATION)
167 {
168 expected_number = 1;
169 }
170
171 /* check proposal numbering */
172 enumerator = this->proposals->create_enumerator(this->proposals);
173 while (enumerator->enumerate(enumerator, (void**)&substruct))
174 {
175 current_number = substruct->get_proposal_number(substruct);
176 if (current_number < expected_number)
177 {
178 if (current_number != expected_number + 1)
179 {
180 DBG1(DBG_ENC, "proposal number is %d, expected %d or %d",
181 current_number, expected_number, expected_number + 1);
182 status = FAILED;
183 break;
184 }
185 }
186 else if (current_number < expected_number)
187 {
188 DBG1(DBG_ENC, "proposal number smaller than previous");
189 status = FAILED;
190 break;
191 }
192
193 status = substruct->payload_interface.verify(&substruct->payload_interface);
194 if (status != SUCCESS)
195 {
196 DBG1(DBG_ENC, "PROPOSAL_SUBSTRUCTURE verification failed");
197 break;
198 }
199 expected_number = current_number;
200 }
201 enumerator->destroy(enumerator);
202 return status;
203 }
204
205 METHOD(payload_t, get_encoding_rules, void,
206 private_sa_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
207 {
208 if (this->type == SECURITY_ASSOCIATION_V1)
209 {
210 *rules = encodings_v1;
211 *rule_count = countof(encodings_v1);
212 }
213 else
214 {
215 *rules = encodings_v2;
216 *rule_count = countof(encodings_v2);
217 }
218 }
219
220 METHOD(payload_t, get_type, payload_type_t,
221 private_sa_payload_t *this)
222 {
223 return this->type;
224 }
225
226 METHOD(payload_t, get_next_type, payload_type_t,
227 private_sa_payload_t *this)
228 {
229 return this->next_payload;
230 }
231
232 METHOD(payload_t, set_next_type, void,
233 private_sa_payload_t *this,payload_type_t type)
234 {
235 this->next_payload = type;
236 }
237
238 /**
239 * recompute length of the payload.
240 */
241 static void compute_length(private_sa_payload_t *this)
242 {
243 enumerator_t *enumerator;
244 payload_t *current;
245 size_t length = SA_PAYLOAD_HEADER_LENGTH;
246
247 if (this->type == SECURITY_ASSOCIATION_V1)
248 {
249 length = SA_PAYLOAD_V1_HEADER_LENGTH;
250 }
251
252 enumerator = this->proposals->create_enumerator(this->proposals);
253 while (enumerator->enumerate(enumerator, (void **)&current))
254 {
255 length += current->get_length(current);
256 }
257 enumerator->destroy(enumerator);
258
259 this->payload_length = length;
260 }
261
262 METHOD(payload_t, get_length, size_t,
263 private_sa_payload_t *this)
264 {
265 return this->payload_length;
266 }
267
268 METHOD(sa_payload_t, add_proposal, void,
269 private_sa_payload_t *this, proposal_t *proposal)
270 {
271 proposal_substructure_t *substruct, *last;
272 payload_type_t subtype = PROPOSAL_SUBSTRUCTURE;
273 u_int count;
274
275 if (this->type == SECURITY_ASSOCIATION_V1)
276 {
277 subtype = PROPOSAL_SUBSTRUCTURE_V1;
278 }
279 substruct = proposal_substructure_create_from_proposal(subtype, proposal);
280 count = this->proposals->get_count(this->proposals);
281 if (count > 0)
282 {
283 this->proposals->get_last(this->proposals, (void**)&last);
284 /* last transform is now not anymore last one */
285 last->set_is_last_proposal(last, FALSE);
286 }
287 substruct->set_is_last_proposal(substruct, TRUE);
288 if (proposal->get_number(proposal))
289 { /* use the selected proposals number, if any */
290 substruct->set_proposal_number(substruct, proposal->get_number(proposal));
291 }
292 else
293 {
294 substruct->set_proposal_number(substruct, count + 1);
295 }
296 this->proposals->insert_last(this->proposals, substruct);
297 compute_length(this);
298 }
299
300 METHOD(sa_payload_t, get_proposals, linked_list_t*,
301 private_sa_payload_t *this)
302 {
303 int struct_number = 0;
304 int ignore_struct_number = 0;
305 enumerator_t *enumerator;
306 proposal_substructure_t *substruct;
307 linked_list_t *list;
308 proposal_t *proposal;
309
310 if (this->type == SECURITY_ASSOCIATION_V1)
311 { /* IKEv1 proposals start with 0 */
312 struct_number = ignore_struct_number = -1;
313 }
314
315 list = linked_list_create();
316 /* we do not support proposals split up to two proposal substructures, as
317 * AH+ESP bundles are not supported in RFC4301 anymore.
318 * To handle such structures safely, we just skip proposals with multiple
319 * protocols.
320 */
321 enumerator = this->proposals->create_enumerator(this->proposals);
322 while (enumerator->enumerate(enumerator, &substruct))
323 {
324 /* check if a proposal has a single protocol */
325 if (substruct->get_proposal_number(substruct) == struct_number)
326 {
327 if (ignore_struct_number < struct_number)
328 {
329 /* remove an already added, if first of series */
330 list->remove_last(list, (void**)&proposal);
331 proposal->destroy(proposal);
332 ignore_struct_number = struct_number;
333 }
334 continue;
335 }
336 struct_number++;
337 proposal = substruct->get_proposal(substruct);
338 if (proposal)
339 {
340 list->insert_last(list, proposal);
341 }
342 }
343 enumerator->destroy(enumerator);
344 return list;
345 }
346
347 METHOD(sa_payload_t, create_substructure_enumerator, enumerator_t*,
348 private_sa_payload_t *this)
349 {
350 return this->proposals->create_enumerator(this->proposals);
351 }
352
353 METHOD2(payload_t, sa_payload_t, destroy, void,
354 private_sa_payload_t *this)
355 {
356 this->proposals->destroy_offset(this->proposals,
357 offsetof(payload_t, destroy));
358 free(this);
359 }
360
361 /*
362 * Described in header.
363 */
364 sa_payload_t *sa_payload_create(payload_type_t type)
365 {
366 private_sa_payload_t *this;
367
368 INIT(this,
369 .public = {
370 .payload_interface = {
371 .verify = _verify,
372 .get_encoding_rules = _get_encoding_rules,
373 .get_length = _get_length,
374 .get_next_type = _get_next_type,
375 .set_next_type = _set_next_type,
376 .get_type = _get_type,
377 .destroy = _destroy,
378 },
379 .add_proposal = _add_proposal,
380 .get_proposals = _get_proposals,
381 .create_substructure_enumerator = _create_substructure_enumerator,
382 .destroy = _destroy,
383 },
384 .next_payload = NO_PAYLOAD,
385 .proposals = linked_list_create(),
386 .type = type,
387 /* for IKEv1 only */
388 .doi = IKEV1_DOI_IPSEC,
389 .situation = SIT_IDENTITY_ONLY,
390 );
391
392 compute_length(this);
393
394 return &this->public;
395 }
396
397 /*
398 * Described in header.
399 */
400 sa_payload_t *sa_payload_create_from_proposal_list(payload_type_t type,
401 linked_list_t *proposals)
402 {
403 sa_payload_t *this;
404 enumerator_t *enumerator;
405 proposal_t *proposal;
406
407 this = sa_payload_create(type);
408 enumerator = proposals->create_enumerator(proposals);
409 while (enumerator->enumerate(enumerator, &proposal))
410 {
411 this->add_proposal(this, proposal);
412 }
413 enumerator->destroy(enumerator);
414
415 return this;
416 }
417
418 /*
419 * Described in header.
420 */
421 sa_payload_t *sa_payload_create_from_proposal(payload_type_t type,
422 proposal_t *proposal)
423 {
424 sa_payload_t *this;
425
426 this = sa_payload_create(type);
427 this->add_proposal(this, proposal);
428
429 return this;
430 }