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
  71 /**
  72  * Create AEAD transforms from given key chunks.
  73  *
  74  * @param in                    inbound AEAD transform to allocate, NULL if failed
  75  * @param out                   outbound AEAD transform to allocate, NULL if failed
  76  * @param sk_ai                 SK_ai key chunk
  77  * @param sk_ar                 SK_ar key chunk
  78  * @param sk_ei                 SK_ei key chunk
  79  * @param sk_er                 SK_er key chunk
  80  * @param enc_alg               encryption algorithm to use
  81  * @param int_alg               integrity algorithm to use
  82  * @param key_size              encryption key size in bytes
  83  * @param initiator             TRUE if initiator
  84  */
  85 static void aead_create_from_keys(aead_t **in, aead_t **out,
  86            const chunk_t * const sk_ai, const chunk_t * const sk_ar,
  87            const chunk_t * const sk_ei, const chunk_t * const sk_er,
  88            const u_int16_t enc_alg, const u_int16_t int_alg,
  89            const u_int16_t key_size, bool initiator)
  90 {
  91         *in = *out = NULL;
  92
  93         signer_t * const signer_i = lib->crypto->create_signer(lib->crypto, int_alg);
  94         signer_t * const signer_r = lib->crypto->create_signer(lib->crypto, int_alg);
  95         if (signer_i == NULL || signer_r == NULL)
  96         {
  97                 DBG1(DBG_IKE, "%N %N not supported!",
  98                          transform_type_names, INTEGRITY_ALGORITHM,
  99                          integrity_algorithm_names, int_alg);
 100                 return;
 101         }
 102         crypter_t * const crypter_i = lib->crypto->create_crypter(lib->crypto,
 103                         enc_alg, key_size);
 104         crypter_t * const crypter_r = lib->crypto->create_crypter(lib->crypto,
 105                         enc_alg, key_size);
 106         if (crypter_i == NULL || crypter_r == NULL)
 107         {
 108                 signer_i->destroy(signer_i);
 109                 signer_r->destroy(signer_r);
 110                 DBG1(DBG_IKE, "%N %N (key size %d) not supported!",
 111                          transform_type_names, ENCRYPTION_ALGORITHM,
 112                          encryption_algorithm_names, enc_alg, key_size);
 113                 return;
 114         }
 115
 116         DBG4(DBG_IKE, "Sk_ai %B", sk_ai);
 117         if (!signer_i->set_key(signer_i, *sk_ai))
 118         {
 119                 return;
 120         }
 121         DBG4(DBG_IKE, "Sk_ar %B", sk_ar);
 122         if (!signer_r->set_key(signer_r, *sk_ar))
 123         {
 124                 return;
 125         }
 126         DBG4(DBG_IKE, "Sk_ei %B", sk_ei);
 127         if (!crypter_i->set_key(crypter_i, *sk_ei))
 128         {
 129                 return;
 130         }
 131         DBG4(DBG_IKE, "Sk_er %B", sk_er);
 132         if (!crypter_r->set_key(crypter_r, *sk_er))
 133         {
 134                 return;
 135         }
 136
 137         if (initiator)
 138         {
 139                 *in = aead_create(crypter_r, signer_r);
 140                 *out = aead_create(crypter_i, signer_i);
 141         }
 142         else
 143         {
 144                 *in = aead_create(crypter_i, signer_i);
 145                 *out = aead_create(crypter_r, signer_r);
 146         }
 147 }
 148
 149 METHOD(keymat_t, get_version, ike_version_t,
 150         private_tkm_keymat_t *this)
 151 {
 152         return IKEV2;
 153 }
 154
 155 METHOD(keymat_t, create_dh, diffie_hellman_t*,
 156         private_tkm_keymat_t *this, diffie_hellman_group_t group)
 157 {
 158         return lib->crypto->create_dh(lib->crypto, group);
 159 }
 160
 161 METHOD(keymat_t, create_nonce_gen, nonce_gen_t*,
 162         private_tkm_keymat_t *this)
 163 {
 164         return lib->crypto->create_nonce_gen(lib->crypto);
 165 }
 166
 167 METHOD(keymat_v2_t, derive_ike_keys, bool,
 168         private_tkm_keymat_t *this, proposal_t *proposal, diffie_hellman_t *dh,
 169         chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id,
 170         pseudo_random_function_t rekey_function, chunk_t rekey_skd)
 171 {
 172         /* Check encryption and integrity algorithms */
 173         u_int16_t enc_alg, int_alg, key_size;
 174         if (!proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &enc_alg, &key_size))
 175         {
 176                 DBG1(DBG_IKE, "no %N selected", transform_type_names,
 177                                 ENCRYPTION_ALGORITHM);
 178                 return FALSE;
 179         }
 180         if (encryption_algorithm_is_aead(enc_alg))
 181         {
 182                 DBG1(DBG_IKE, "AEAD algorithm %N not supported",
 183                            encryption_algorithm_names, enc_alg);
 184                 return FALSE;
 185         }
 186         if (!proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &int_alg, NULL))
 187         {
 188                 DBG1(DBG_IKE, "no %N selected", transform_type_names,
 189                                 INTEGRITY_ALGORITHM);
 190                 return FALSE;
 191         }
 192         if (!(enc_alg == ENCR_AES_CBC && key_size == 256 &&
 193                         int_alg == AUTH_HMAC_SHA2_512_256))
 194         {
 195                 DBG1(DBG_IKE, "the TKM only supports aes256-sha512 at the moment, please"
 196                                 " update your configuration");
 197                 return FALSE;
 198         }
 199
 200         DBG2(DBG_IKE, "using %N for encryption, %N for integrity",
 201                         encryption_algorithm_names, enc_alg,
 202                         integrity_algorithm_names, int_alg);
 203
 204         /* Acquire nonce context id */
 205         chunk_t * const nonce = this->initiator ? &nonce_i : &nonce_r;
 206         const uint64_t nc_id = tkm->chunk_map->get_id(tkm->chunk_map, nonce);
 207         if (!nc_id)
 208         {
 209                 DBG1(DBG_IKE, "unable to acquire context id for nonce");
 210                 return FALSE;
 211         }
 212
 213         /* Get DH context id */
 214         tkm_diffie_hellman_t * const tkm_dh = (tkm_diffie_hellman_t *)dh;
 215         const dh_id_type dh_id = tkm_dh->get_id(tkm_dh);
 216
 217         nonce_type nonce_rem;
 218         u_int64_t spi_loc, spi_rem;
 219
 220         if (this->initiator)
 221         {
 222                 chunk_to_sequence(&nonce_r, &nonce_rem);
 223                 spi_loc = id->get_initiator_spi(id);
 224                 spi_rem = id->get_responder_spi(id);
 225         }
 226         else
 227         {
 228                 chunk_to_sequence(&nonce_i, &nonce_rem);
 229                 spi_loc = id->get_responder_spi(id);
 230                 spi_rem = id->get_initiator_spi(id);
 231         }
 232
 233         result_type res;
 234         key_type sk_ai, sk_ar, sk_ei, sk_er;
 235         if (rekey_function == PRF_UNDEFINED)
 236         {
 237                 this->ae_ctx_id = tkm->idmgr->acquire_id(tkm->idmgr, TKM_CTX_AE);
 238                 if (!this->ae_ctx_id)
 239                 {
 240                         DBG1(DBG_IKE, "unable to acquire ae context id");
 241                         return FALSE;
 242                 }
 243                 DBG1(DBG_IKE, "deriving IKE keys (nc: %llu, dh: %llu, spi_loc: %llx, "
 244                          "spi_rem: %llx)", nc_id, dh_id, spi_loc, spi_rem);
 245                 res = ike_isa_create(this->isa_ctx_id, this->ae_ctx_id, 1, dh_id, nc_id,
 246                                                          nonce_rem, this->initiator, spi_loc, spi_rem,
 247                                                          &sk_ai, &sk_ar, &sk_ei, &sk_er);
 248         }
 249         else
 250         {
 251                 if (rekey_skd.ptr == NULL || rekey_skd.len != sizeof(isa_info_t))
 252                 {
 253                         DBG1(DBG_IKE, "unable to retrieve parent isa info");
 254                         return FALSE;
 255                 }
 256                 const isa_info_t isa_info = *((isa_info_t *)(rekey_skd.ptr));
 257                 DBG1(DBG_IKE, "deriving IKE keys (parent_isa: %llu, ae: %llu, nc: %llu,"
 258                          "dh: %llu, spi_loc: %llx, spi_rem: %llx)", isa_info.parent_isa_id,
 259                          isa_info.ae_id, nc_id, dh_id, spi_loc, spi_rem);
 260                 this->ae_ctx_id = isa_info.ae_id;
 261                 res = ike_isa_create_child(this->isa_ctx_id, isa_info.parent_isa_id, 1,
 262                                                                    dh_id, nc_id, nonce_rem, this->initiator,
 263                                                                    spi_loc, spi_rem, &sk_ai, &sk_ar, &sk_ei,
 264                                                                    &sk_er);
 265                 chunk_free(&rekey_skd);
 266         }
 267
 268         if (res != TKM_OK)
 269         {
 270                 DBG1(DBG_IKE, "key derivation failed (isa: %llu)", this->isa_ctx_id);
 271                 return FALSE;
 272         }
 273
 274         chunk_t c_ai, c_ar, c_ei, c_er;
 275         sequence_to_chunk(sk_ai.data, sk_ai.size, &c_ai);
 276         sequence_to_chunk(sk_ar.data, sk_ar.size, &c_ar);
 277         sequence_to_chunk(sk_ei.data, sk_ei.size, &c_ei);
 278         sequence_to_chunk(sk_er.data, sk_er.size, &c_er);
 279
 280         aead_create_from_keys(&this->aead_in, &this->aead_out,
 281                         &c_ai, &c_ar, &c_ei, &c_er,
 282                         enc_alg, int_alg, key_size / 8, this->initiator);
 283
 284         chunk_clear(&c_ai);
 285         chunk_clear(&c_ar);
 286         chunk_clear(&c_ei);
 287         chunk_clear(&c_er);
 288
 289         if (!this->aead_in || !this->aead_out)
 290         {
 291                 DBG1(DBG_IKE, "could not initialize AEAD transforms");
 292                 return FALSE;
 293         }
 294
 295         /* TODO: Add failure handler (see keymat_v2.c) */
 296
 297         tkm->chunk_map->remove(tkm->chunk_map, nonce);
 298         if (ike_nc_reset(nc_id) != TKM_OK)
 299         {
 300                 DBG1(DBG_IKE, "failed to reset nonce context %llu", nc_id);
 301         }
 302         tkm->idmgr->release_id(tkm->idmgr, TKM_CTX_NONCE, nc_id);
 303
 304         return TRUE;
 305 }
 306
 307 METHOD(keymat_v2_t, derive_child_keys, bool,
 308         private_tkm_keymat_t *this, proposal_t *proposal, diffie_hellman_t *dh,
 309         chunk_t nonce_i, chunk_t nonce_r, chunk_t *encr_i, chunk_t *integ_i,
 310         chunk_t *encr_r, chunk_t *integ_r)
 311 {
 312         esa_info_t *esa_info_i, *esa_info_r;
 313
 314         dh_id_type dh_id = 0;
 315         if (dh)
 316         {
 317                 dh_id = ((tkm_diffie_hellman_t *)dh)->get_id((tkm_diffie_hellman_t *)dh);
 318         }
 319
 320         INIT(esa_info_i,
 321                  .isa_id = this->isa_ctx_id,
 322                  .spi_r = proposal->get_spi(proposal),
 323                  .nonce_i = chunk_clone(nonce_i),
 324                  .nonce_r = chunk_clone(nonce_r),
 325                  .is_encr_r = FALSE,
 326                  .dh_id = dh_id,
 327         );
 328
 329         INIT(esa_info_r,
 330                  .isa_id = this->isa_ctx_id,
 331                  .spi_r = proposal->get_spi(proposal),
 332                  .nonce_i = chunk_clone(nonce_i),
 333                  .nonce_r = chunk_clone(nonce_r),
 334                  .is_encr_r = TRUE,
 335                  .dh_id = dh_id,
 336         );
 337
 338         DBG1(DBG_CHD, "passing on esa info (isa: %llu, spi_r: %x, dh_id: %llu)",
 339                  esa_info_i->isa_id, ntohl(esa_info_i->spi_r), esa_info_i->dh_id);
 340
 341         /* store ESA info in encr_i/r, which is passed to add_sa */
 342         *encr_i = chunk_create((u_char *)esa_info_i, sizeof(esa_info_t));
 343         *encr_r = chunk_create((u_char *)esa_info_r, sizeof(esa_info_t));
 344         *integ_i = chunk_empty;
 345         *integ_r = chunk_empty;
 346
 347         return TRUE;
 348 }
 349
 350 METHOD(keymat_t, get_aead, aead_t*,
 351         private_tkm_keymat_t *this, bool in)
 352 {
 353         return in ? this->aead_in : this->aead_out;
 354 }
 355
 356 METHOD(keymat_v2_t, get_auth_octets, bool,
 357         private_tkm_keymat_t *this, bool verify, chunk_t ike_sa_init,
 358         chunk_t nonce, identification_t *id, char reserved[3], chunk_t *octets)
 359 {
 360         DBG1(DBG_IKE, "returning auth octets");
 361         *octets = chunk_empty;
 362         return TRUE;
 363 }
 364
 365 METHOD(keymat_v2_t, get_skd, pseudo_random_function_t,
 366         private_tkm_keymat_t *this, chunk_t *skd)
 367 {
 368         isa_info_t *isa_info;
 369
 370         INIT(isa_info,
 371                  .parent_isa_id = this->isa_ctx_id,
 372                  .ae_id = this->ae_ctx_id,
 373         );
 374
 375         *skd = chunk_create((u_char *)isa_info, sizeof(isa_info_t));
 376
 377         /*
 378          * remove ae context id, since control has now been handed over to the new
 379          * IKE SA keymat
 380          */
 381         this->ae_ctx_id = 0;
 382         return PRF_HMAC_SHA2_512;
 383 }
 384
 385 METHOD(keymat_v2_t, get_psk_sig, bool,
 386         private_tkm_keymat_t *this, bool verify, chunk_t ike_sa_init, chunk_t nonce,
 387         chunk_t secret, identification_t *id, char reserved[3], chunk_t *sig)
 388 {
 389         DBG1(DBG_IKE, "returning %s PSK signature", verify ? "remote" : "local");
 390
 391         signature_type signature;
 392         init_message_type msg;
 393         chunk_to_sequence(&ike_sa_init, &msg);
 394
 395         chunk_t idx_chunk, chunk = chunk_alloca(4);
 396         chunk.ptr[0] = id->get_type(id);
 397         memcpy(chunk.ptr + 1, reserved, 3);
 398         idx_chunk = chunk_cata("cc", chunk, id->get_encoding(id));
 399         idx_type idx;
 400         chunk_to_sequence(&idx_chunk, &idx);
 401
 402         if (ike_isa_sign_psk(this->isa_ctx_id, msg, idx, verify == TRUE, &signature)
 403                         != TKM_OK)
 404         {
 405                 DBG1(DBG_IKE, "get %s PSK signature failed", verify ?
 406                                 "remote" : "local");
 407                 return FALSE;
 408         }
 409
 410         sequence_to_chunk(&signature.data[0], signature.size, sig);
 411         return TRUE;
 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         free(this);
 436 }
 437
 438 METHOD(tkm_keymat_t, get_isa_id, isa_id_type,
 439         private_tkm_keymat_t *this)
 440 {
 441         return this->isa_ctx_id;
 442 }
 443
 444 METHOD(tkm_keymat_t, set_auth_payload, void,
 445         private_tkm_keymat_t *this, const chunk_t * const payload)
 446 {
 447         this->auth_payload = chunk_clone(*payload);
 448 }
 449
 450 METHOD(tkm_keymat_t, get_auth_payload, chunk_t*,
 451         private_tkm_keymat_t *this)
 452 {
 453         return &this->auth_payload;
 454 }
 455
 456 /**
 457  * See header.
 458  */
 459 tkm_keymat_t *tkm_keymat_create(bool initiator)
 460 {
 461         private_tkm_keymat_t *this;
 462
 463         INIT(this,
 464                 .public = {
 465                         .keymat_v2 = {
 466                                 .keymat = {
 467                                         .get_version = _get_version,
 468                                         .create_dh = _create_dh,
 469                                         .create_nonce_gen = _create_nonce_gen,
 470                                         .get_aead = _get_aead,
 471                                         .destroy = _destroy,
 472                                 },
 473                                 .derive_ike_keys = _derive_ike_keys,
 474                                 .derive_child_keys = _derive_child_keys,
 475                                 .get_skd = _get_skd,
 476                                 .get_auth_octets = _get_auth_octets,
 477                                 .get_psk_sig = _get_psk_sig,
 478                         },
 479                         .get_isa_id = _get_isa_id,
 480                         .set_auth_payload = _set_auth_payload,
 481                         .get_auth_payload = _get_auth_payload,
 482                 },
 483                 .initiator = initiator,
 484                 .isa_ctx_id = tkm->idmgr->acquire_id(tkm->idmgr, TKM_CTX_ISA),
 485                 .ae_ctx_id = 0,
 486                 .auth_payload = chunk_empty,
 487         );
 488
 489         if (!this->isa_ctx_id)
 490         {
 491                 free(this);
 492                 return NULL;
 493         }
 494
 495         return &this->public;
 496 }