fe4caf9ece492a3f089eec27b857d466d2b2d898
[strongswan.git] / src / charon-tkm / src / tkm / tkm_keymat.c
1 /*
2 * Copyrigth (C) 2012 Reto Buerki
3 * Copyright (C) 2012 Adrian-Ken Rueegsegger
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 <daemon.h>
18 #include <tkm/constants.h>
19 #include <tkm/client.h>
20
21 #include "tkm.h"
22 #include "tkm_types.h"
23 #include "tkm_utils.h"
24 #include "tkm_diffie_hellman.h"
25 #include "tkm_keymat.h"
26
27 typedef struct private_tkm_keymat_t private_tkm_keymat_t;
28
29 /**
30 * Private data of a keymat_t object.
31 */
32 struct private_tkm_keymat_t {
33
34 /**
35 * Public tkm_keymat_t interface.
36 */
37 tkm_keymat_t public;
38
39 /**
40 * IKE_SA Role, initiator or responder.
41 */
42 bool initiator;
43
44 /**
45 * Inbound AEAD.
46 */
47 aead_t *aead_in;
48
49 /**
50 * Outbound AEAD.
51 */
52 aead_t *aead_out;
53
54 /**
55 * ISA context id.
56 */
57 isa_id_type isa_ctx_id;
58
59 /**
60 * AE context id.
61 */
62 ae_id_type ae_ctx_id;
63
64 /**
65 * AUTH payload chunk.
66 */
67 chunk_t auth_payload;
68
69 /**
70 * Peer init message chunk.
71 */
72 chunk_t other_init_msg;
73
74 };
75
76 /**
77 * Create AEAD transforms from given key chunks.
78 *
79 * @param in inbound AEAD transform to allocate, NULL if failed
80 * @param out outbound AEAD transform to allocate, NULL if failed
81 * @param sk_ai SK_ai key chunk
82 * @param sk_ar SK_ar key chunk
83 * @param sk_ei SK_ei key chunk
84 * @param sk_er SK_er key chunk
85 * @param enc_alg encryption algorithm to use
86 * @param int_alg integrity algorithm to use
87 * @param key_size encryption key size in bytes
88 * @param initiator TRUE if initiator
89 */
90 static void aead_create_from_keys(aead_t **in, aead_t **out,
91 const chunk_t * const sk_ai, const chunk_t * const sk_ar,
92 const chunk_t * const sk_ei, const chunk_t * const sk_er,
93 const u_int16_t enc_alg, const u_int16_t int_alg,
94 const u_int16_t key_size, bool initiator)
95 {
96 *in = *out = NULL;
97
98 signer_t * const signer_i = lib->crypto->create_signer(lib->crypto, int_alg);
99 signer_t * const signer_r = lib->crypto->create_signer(lib->crypto, int_alg);
100 if (signer_i == NULL || signer_r == NULL)
101 {
102 DBG1(DBG_IKE, "%N %N not supported!",
103 transform_type_names, INTEGRITY_ALGORITHM,
104 integrity_algorithm_names, int_alg);
105 return;
106 }
107 crypter_t * const crypter_i = lib->crypto->create_crypter(lib->crypto,
108 enc_alg, key_size);
109 crypter_t * const crypter_r = lib->crypto->create_crypter(lib->crypto,
110 enc_alg, key_size);
111 if (crypter_i == NULL || crypter_r == NULL)
112 {
113 signer_i->destroy(signer_i);
114 signer_r->destroy(signer_r);
115 DBG1(DBG_IKE, "%N %N (key size %d) not supported!",
116 transform_type_names, ENCRYPTION_ALGORITHM,
117 encryption_algorithm_names, enc_alg, key_size);
118 return;
119 }
120
121 DBG4(DBG_IKE, "Sk_ai %B", sk_ai);
122 if (!signer_i->set_key(signer_i, *sk_ai))
123 {
124 return;
125 }
126 DBG4(DBG_IKE, "Sk_ar %B", sk_ar);
127 if (!signer_r->set_key(signer_r, *sk_ar))
128 {
129 return;
130 }
131 DBG4(DBG_IKE, "Sk_ei %B", sk_ei);
132 if (!crypter_i->set_key(crypter_i, *sk_ei))
133 {
134 return;
135 }
136 DBG4(DBG_IKE, "Sk_er %B", sk_er);
137 if (!crypter_r->set_key(crypter_r, *sk_er))
138 {
139 return;
140 }
141
142 if (initiator)
143 {
144 *in = aead_create(crypter_r, signer_r);
145 *out = aead_create(crypter_i, signer_i);
146 }
147 else
148 {
149 *in = aead_create(crypter_i, signer_i);
150 *out = aead_create(crypter_r, signer_r);
151 }
152 }
153
154 METHOD(keymat_t, get_version, ike_version_t,
155 private_tkm_keymat_t *this)
156 {
157 return IKEV2;
158 }
159
160 METHOD(keymat_t, create_dh, diffie_hellman_t*,
161 private_tkm_keymat_t *this, diffie_hellman_group_t group)
162 {
163 return lib->crypto->create_dh(lib->crypto, group);
164 }
165
166 METHOD(keymat_t, create_nonce_gen, nonce_gen_t*,
167 private_tkm_keymat_t *this)
168 {
169 return lib->crypto->create_nonce_gen(lib->crypto);
170 }
171
172 METHOD(keymat_v2_t, derive_ike_keys, bool,
173 private_tkm_keymat_t *this, proposal_t *proposal, diffie_hellman_t *dh,
174 chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id,
175 pseudo_random_function_t rekey_function, chunk_t rekey_skd)
176 {
177 /* Check encryption and integrity algorithms */
178 u_int16_t enc_alg, int_alg, key_size;
179 if (!proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &enc_alg, &key_size))
180 {
181 DBG1(DBG_IKE, "no %N selected", transform_type_names,
182 ENCRYPTION_ALGORITHM);
183 return FALSE;
184 }
185 if (encryption_algorithm_is_aead(enc_alg))
186 {
187 DBG1(DBG_IKE, "AEAD algorithm %N not supported",
188 encryption_algorithm_names, enc_alg);
189 return FALSE;
190 }
191 if (!proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &int_alg, NULL))
192 {
193 DBG1(DBG_IKE, "no %N selected", transform_type_names,
194 INTEGRITY_ALGORITHM);
195 return FALSE;
196 }
197 if (!(enc_alg == ENCR_AES_CBC && key_size == 256 &&
198 int_alg == AUTH_HMAC_SHA2_512_256))
199 {
200 DBG1(DBG_IKE, "the TKM only supports aes256-sha512 at the moment, please"
201 " update your configuration");
202 return FALSE;
203 }
204
205 DBG2(DBG_IKE, "using %N for encryption, %N for integrity",
206 encryption_algorithm_names, enc_alg,
207 integrity_algorithm_names, int_alg);
208
209 /* Acquire nonce context id */
210 chunk_t * const nonce = this->initiator ? &nonce_i : &nonce_r;
211 const uint64_t nc_id = tkm->chunk_map->get_id(tkm->chunk_map, nonce);
212 if (!nc_id)
213 {
214 DBG1(DBG_IKE, "unable to acquire context id for nonce");
215 return FALSE;
216 }
217
218 /* Get DH context id */
219 tkm_diffie_hellman_t * const tkm_dh = (tkm_diffie_hellman_t *)dh;
220 const dh_id_type dh_id = tkm_dh->get_id(tkm_dh);
221
222 nonce_type nonce_rem;
223 u_int64_t spi_loc, spi_rem;
224
225 if (this->initiator)
226 {
227 chunk_to_sequence(&nonce_r, &nonce_rem, sizeof(nonce_type));
228 spi_loc = id->get_initiator_spi(id);
229 spi_rem = id->get_responder_spi(id);
230 }
231 else
232 {
233 chunk_to_sequence(&nonce_i, &nonce_rem, sizeof(nonce_type));
234 spi_loc = id->get_responder_spi(id);
235 spi_rem = id->get_initiator_spi(id);
236 }
237
238 result_type res;
239 key_type sk_ai, sk_ar, sk_ei, sk_er;
240 if (rekey_function == PRF_UNDEFINED)
241 {
242 this->ae_ctx_id = tkm->idmgr->acquire_id(tkm->idmgr, TKM_CTX_AE);
243 if (!this->ae_ctx_id)
244 {
245 DBG1(DBG_IKE, "unable to acquire ae context id");
246 return FALSE;
247 }
248 DBG1(DBG_IKE, "deriving IKE keys (nc: %llu, dh: %llu, spi_loc: %llx, "
249 "spi_rem: %llx)", nc_id, dh_id, spi_loc, spi_rem);
250 res = ike_isa_create(this->isa_ctx_id, this->ae_ctx_id, 1, dh_id, nc_id,
251 nonce_rem, this->initiator, spi_loc, spi_rem,
252 &sk_ai, &sk_ar, &sk_ei, &sk_er);
253 }
254 else
255 {
256 if (rekey_skd.ptr == NULL || rekey_skd.len != sizeof(isa_info_t))
257 {
258 DBG1(DBG_IKE, "unable to retrieve parent isa info");
259 return FALSE;
260 }
261 const isa_info_t isa_info = *((isa_info_t *)(rekey_skd.ptr));
262 DBG1(DBG_IKE, "deriving IKE keys (parent_isa: %llu, ae: %llu, nc: %llu,"
263 "dh: %llu, spi_loc: %llx, spi_rem: %llx)", isa_info.parent_isa_id,
264 isa_info.ae_id, nc_id, dh_id, spi_loc, spi_rem);
265 this->ae_ctx_id = isa_info.ae_id;
266 res = ike_isa_create_child(this->isa_ctx_id, isa_info.parent_isa_id, 1,
267 dh_id, nc_id, nonce_rem, this->initiator,
268 spi_loc, spi_rem, &sk_ai, &sk_ar, &sk_ei,
269 &sk_er);
270 chunk_free(&rekey_skd);
271 }
272
273 if (res != TKM_OK)
274 {
275 DBG1(DBG_IKE, "key derivation failed (isa: %llu)", this->isa_ctx_id);
276 return FALSE;
277 }
278
279 chunk_t c_ai, c_ar, c_ei, c_er;
280 sequence_to_chunk(sk_ai.data, sk_ai.size, &c_ai);
281 sequence_to_chunk(sk_ar.data, sk_ar.size, &c_ar);
282 sequence_to_chunk(sk_ei.data, sk_ei.size, &c_ei);
283 sequence_to_chunk(sk_er.data, sk_er.size, &c_er);
284
285 aead_create_from_keys(&this->aead_in, &this->aead_out,
286 &c_ai, &c_ar, &c_ei, &c_er,
287 enc_alg, int_alg, key_size / 8, this->initiator);
288
289 chunk_clear(&c_ai);
290 chunk_clear(&c_ar);
291 chunk_clear(&c_ei);
292 chunk_clear(&c_er);
293
294 if (!this->aead_in || !this->aead_out)
295 {
296 DBG1(DBG_IKE, "could not initialize AEAD transforms");
297 return FALSE;
298 }
299
300 /* TODO: Add failure handler (see keymat_v2.c) */
301
302 tkm->chunk_map->remove(tkm->chunk_map, nonce);
303 if (ike_nc_reset(nc_id) != TKM_OK)
304 {
305 DBG1(DBG_IKE, "failed to reset nonce context %llu", nc_id);
306 }
307 tkm->idmgr->release_id(tkm->idmgr, TKM_CTX_NONCE, nc_id);
308
309 return TRUE;
310 }
311
312 METHOD(keymat_v2_t, derive_child_keys, bool,
313 private_tkm_keymat_t *this, proposal_t *proposal, diffie_hellman_t *dh,
314 chunk_t nonce_i, chunk_t nonce_r, chunk_t *encr_i, chunk_t *integ_i,
315 chunk_t *encr_r, chunk_t *integ_r)
316 {
317 esa_info_t *esa_info_i, *esa_info_r;
318
319 dh_id_type dh_id = 0;
320 if (dh)
321 {
322 dh_id = ((tkm_diffie_hellman_t *)dh)->get_id((tkm_diffie_hellman_t *)dh);
323 }
324
325 INIT(esa_info_i,
326 .isa_id = this->isa_ctx_id,
327 .spi_r = proposal->get_spi(proposal),
328 .nonce_i = chunk_clone(nonce_i),
329 .nonce_r = chunk_clone(nonce_r),
330 .is_encr_r = FALSE,
331 .dh_id = dh_id,
332 );
333
334 INIT(esa_info_r,
335 .isa_id = this->isa_ctx_id,
336 .spi_r = proposal->get_spi(proposal),
337 .nonce_i = chunk_clone(nonce_i),
338 .nonce_r = chunk_clone(nonce_r),
339 .is_encr_r = TRUE,
340 .dh_id = dh_id,
341 );
342
343 DBG1(DBG_CHD, "passing on esa info (isa: %llu, spi_r: %x, dh_id: %llu)",
344 esa_info_i->isa_id, ntohl(esa_info_i->spi_r), esa_info_i->dh_id);
345
346 /* store ESA info in encr_i/r, which is passed to add_sa */
347 *encr_i = chunk_create((u_char *)esa_info_i, sizeof(esa_info_t));
348 *encr_r = chunk_create((u_char *)esa_info_r, sizeof(esa_info_t));
349 *integ_i = chunk_empty;
350 *integ_r = chunk_empty;
351
352 return TRUE;
353 }
354
355 METHOD(keymat_t, get_aead, aead_t*,
356 private_tkm_keymat_t *this, bool in)
357 {
358 return in ? this->aead_in : this->aead_out;
359 }
360
361 METHOD(keymat_v2_t, get_auth_octets, bool,
362 private_tkm_keymat_t *this, bool verify, chunk_t ike_sa_init,
363 chunk_t nonce, identification_t *id, char reserved[3], chunk_t *octets)
364 {
365 if (verify)
366 {
367 /* store peer init message for authentication step */
368 this->other_init_msg = chunk_clone(ike_sa_init);
369 *octets = chunk_empty;
370 return TRUE;
371 }
372
373 sign_info_t *sign;
374 INIT(sign,
375 .isa_id = this->isa_ctx_id,
376 .init_message = chunk_clone(ike_sa_init),
377 );
378
379 /*
380 * store signature info in AUTH octets, which is passed to the private key
381 * sign() operation
382 */
383 *octets = chunk_create((u_char *)sign, sizeof(sign_info_t));
384 return TRUE;
385 }
386
387 METHOD(keymat_v2_t, get_skd, pseudo_random_function_t,
388 private_tkm_keymat_t *this, chunk_t *skd)
389 {
390 isa_info_t *isa_info;
391
392 INIT(isa_info,
393 .parent_isa_id = this->isa_ctx_id,
394 .ae_id = this->ae_ctx_id,
395 );
396
397 *skd = chunk_create((u_char *)isa_info, sizeof(isa_info_t));
398
399 /*
400 * remove ae context id, since control has now been handed over to the new
401 * IKE SA keymat
402 */
403 this->ae_ctx_id = 0;
404 return PRF_HMAC_SHA2_512;
405 }
406
407 METHOD(keymat_v2_t, get_psk_sig, bool,
408 private_tkm_keymat_t *this, bool verify, chunk_t ike_sa_init, chunk_t nonce,
409 chunk_t secret, identification_t *id, char reserved[3], chunk_t *sig)
410 {
411 return FALSE;
412 }
413
414 METHOD(keymat_t, destroy, void,
415 private_tkm_keymat_t *this)
416 {
417 if (ike_isa_reset(this->isa_ctx_id) != TKM_OK)
418 {
419 DBG1(DBG_IKE, "failed to reset ISA context %d", this->isa_ctx_id);
420 }
421 tkm->idmgr->release_id(tkm->idmgr, TKM_CTX_ISA, this->isa_ctx_id);
422 /* only reset ae context if set */
423 if (this->ae_ctx_id != 0)
424 {
425 if (ike_ae_reset(this->ae_ctx_id) != TKM_OK)
426 {
427 DBG1(DBG_IKE, "failed to reset AE context %d", this->ae_ctx_id);
428 }
429 tkm->idmgr->release_id(tkm->idmgr, TKM_CTX_AE, this->ae_ctx_id);
430 }
431
432 DESTROY_IF(this->aead_in);
433 DESTROY_IF(this->aead_out);
434 chunk_free(&this->auth_payload);
435 chunk_free(&this->other_init_msg);
436 free(this);
437 }
438
439 METHOD(tkm_keymat_t, get_isa_id, isa_id_type,
440 private_tkm_keymat_t *this)
441 {
442 return this->isa_ctx_id;
443 }
444
445 METHOD(tkm_keymat_t, set_auth_payload, void,
446 private_tkm_keymat_t *this, const chunk_t * const payload)
447 {
448 this->auth_payload = chunk_clone(*payload);
449 }
450
451 METHOD(tkm_keymat_t, get_auth_payload, chunk_t*,
452 private_tkm_keymat_t *this)
453 {
454 return &this->auth_payload;
455 }
456
457 METHOD(tkm_keymat_t, get_peer_init_msg, chunk_t*,
458 private_tkm_keymat_t *this)
459 {
460 return &this->other_init_msg;
461 }
462
463 /**
464 * See header.
465 */
466 tkm_keymat_t *tkm_keymat_create(bool initiator)
467 {
468 private_tkm_keymat_t *this;
469
470 INIT(this,
471 .public = {
472 .keymat_v2 = {
473 .keymat = {
474 .get_version = _get_version,
475 .create_dh = _create_dh,
476 .create_nonce_gen = _create_nonce_gen,
477 .get_aead = _get_aead,
478 .destroy = _destroy,
479 },
480 .derive_ike_keys = _derive_ike_keys,
481 .derive_child_keys = _derive_child_keys,
482 .get_skd = _get_skd,
483 .get_auth_octets = _get_auth_octets,
484 .get_psk_sig = _get_psk_sig,
485 },
486 .get_isa_id = _get_isa_id,
487 .set_auth_payload = _set_auth_payload,
488 .get_auth_payload = _get_auth_payload,
489 .get_peer_init_msg = _get_peer_init_msg,
490 },
491 .initiator = initiator,
492 .isa_ctx_id = tkm->idmgr->acquire_id(tkm->idmgr, TKM_CTX_ISA),
493 .ae_ctx_id = 0,
494 .auth_payload = chunk_empty,
495 .other_init_msg = chunk_empty,
496 );
497
498 if (!this->isa_ctx_id)
499 {
500 free(this);
501 return NULL;
502 }
503
504 return &this->public;
505 }