src/charon/config/proposal.c

   1 /**
   2  * @file proposal.c
   3  *
   4  * @brief Implementation of proposal_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2006 Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #include <string.h>
  24
  25 #include "proposal.h"
  26
  27 #include <utils/linked_list.h>
  28 #include <utils/identification.h>
  29 #include <utils/lexparser.h>
  30 #include <crypto/prfs/prf.h>
  31 #include <crypto/crypters/crypter.h>
  32 #include <crypto/signers/signer.h>
  33
  34
  35 ENUM(protocol_id_names, PROTO_NONE, PROTO_ESP,
  36         "PROTO_NONE",
  37         "IKE",
  38         "AH",
  39         "ESP",
  40 );
  41
  42 ENUM_BEGIN(transform_type_names, UNDEFINED_TRANSFORM_TYPE, UNDEFINED_TRANSFORM_TYPE,
  43         "UNDEFINED_TRANSFORM_TYPE");
  44 ENUM_NEXT(transform_type_names, ENCRYPTION_ALGORITHM, EXTENDED_SEQUENCE_NUMBERS, UNDEFINED_TRANSFORM_TYPE,
  45         "ENCRYPTION_ALGORITHM",
  46         "PSEUDO_RANDOM_FUNCTION",
  47         "INTEGRITY_ALGORITHM",
  48         "DIFFIE_HELLMAN_GROUP",
  49         "EXTENDED_SEQUENCE_NUMBERS");
  50 ENUM_END(transform_type_names, EXTENDED_SEQUENCE_NUMBERS);
  51
  52 ENUM(extended_sequence_numbers_names, NO_EXT_SEQ_NUMBERS, EXT_SEQ_NUMBERS,
  53         "NO_EXT_SEQ_NUMBERS",
  54         "EXT_SEQ_NUMBERS",
  55 );
  56
  57 typedef struct private_proposal_t private_proposal_t;
  58
  59 /**
  60  * Private data of an proposal_t object
  61  */
  62 struct private_proposal_t {
  63
  64         /**
  65          * Public part
  66          */
  67         proposal_t public;
  68
  69         /**
  70          * protocol (ESP or AH)
  71          */
  72         protocol_id_t protocol;
  73
  74         /**
  75          * priority ordered list of encryption algorithms
  76          */
  77         linked_list_t *encryption_algos;
  78
  79         /**
  80          * priority ordered list of integrity algorithms
  81          */
  82         linked_list_t *integrity_algos;
  83
  84         /**
  85          * priority ordered list of pseudo random functions
  86          */
  87         linked_list_t *prf_algos;
  88
  89         /**
  90          * priority ordered list of dh groups
  91          */
  92         linked_list_t *dh_groups;
  93
  94         /**
  95          * priority ordered list of extended sequence number flags
  96          */
  97         linked_list_t *esns;
  98
  99         /**
 100          * senders SPI
 101          */
 102         u_int64_t spi;
 103 };
 104
 105 /**
 106  * Add algorithm/keysize to a algorithm list
 107  */
 108 static void add_algo(linked_list_t *list, u_int16_t algo, size_t key_size)
 109 {
 110         algorithm_t *algo_key;
 111
 112         algo_key = malloc_thing(algorithm_t);
 113         algo_key->algorithm = algo;
 114         algo_key->key_size = key_size;
 115         list->insert_last(list, (void*)algo_key);
 116 }
 117
 118 /**
 119  * Implements proposal_t.add_algorithm
 120  */
 121 static void add_algorithm(private_proposal_t *this, transform_type_t type, u_int16_t algo, size_t key_size)
 122 {
 123         switch (type)
 124         {
 125                 case ENCRYPTION_ALGORITHM:
 126                         add_algo(this->encryption_algos, algo, key_size);
 127                         break;
 128                 case INTEGRITY_ALGORITHM:
 129                         add_algo(this->integrity_algos, algo, key_size);
 130                         break;
 131                 case PSEUDO_RANDOM_FUNCTION:
 132                         add_algo(this->prf_algos, algo, key_size);
 133                         break;
 134                 case DIFFIE_HELLMAN_GROUP:
 135                         add_algo(this->dh_groups, algo, 0);
 136                         break;
 137                 case EXTENDED_SEQUENCE_NUMBERS:
 138                         add_algo(this->esns, algo, 0);
 139                         break;
 140                 default:
 141                         break;
 142         }
 143 }
 144
 145 /**
 146  * Implements proposal_t.get_algorithm.
 147  */
 148 static bool get_algorithm(private_proposal_t *this, transform_type_t type, algorithm_t** algo)
 149 {
 150         linked_list_t *list;
 151         switch (type)
 152         {
 153                 case ENCRYPTION_ALGORITHM:
 154                         list = this->encryption_algos;
 155                         break;
 156                 case INTEGRITY_ALGORITHM:
 157                         list = this->integrity_algos;
 158                         break;
 159                 case PSEUDO_RANDOM_FUNCTION:
 160                         list = this->prf_algos;
 161                         break;
 162                 case DIFFIE_HELLMAN_GROUP:
 163                         list = this->dh_groups;
 164                         break;
 165                 case EXTENDED_SEQUENCE_NUMBERS:
 166                         list = this->esns;
 167                         break;
 168                 default:
 169                         return FALSE;
 170         }
 171         if (list->get_first(list, (void**)algo) != SUCCESS)
 172         {
 173                 return FALSE;
 174         }
 175         return TRUE;
 176 }
 177
 178 /**
 179  * Implements proposal_t.create_algorithm_iterator.
 180  */
 181 static iterator_t *create_algorithm_iterator(private_proposal_t *this, transform_type_t type)
 182 {
 183         switch (type)
 184         {
 185                 case ENCRYPTION_ALGORITHM:
 186                         return this->encryption_algos->create_iterator(this->encryption_algos, TRUE);
 187                 case INTEGRITY_ALGORITHM:
 188                         return this->integrity_algos->create_iterator(this->integrity_algos, TRUE);
 189                 case PSEUDO_RANDOM_FUNCTION:
 190                         return this->prf_algos->create_iterator(this->prf_algos, TRUE);
 191                 case DIFFIE_HELLMAN_GROUP:
 192                         return this->dh_groups->create_iterator(this->dh_groups, TRUE);
 193                 case EXTENDED_SEQUENCE_NUMBERS:
 194                         return this->esns->create_iterator(this->esns, TRUE);
 195                 default:
 196                         break;
 197         }
 198         return NULL;
 199 }
 200
 201 /**
 202  * Find a matching alg/keysize in two linked lists
 203  */
 204 static bool select_algo(linked_list_t *first, linked_list_t *second, bool *add, u_int16_t *alg, size_t *key_size)
 205 {
 206         iterator_t *first_iter, *second_iter;
 207         algorithm_t *first_alg, *second_alg;
 208
 209         /* if in both are zero algorithms specified, we HAVE a match */
 210         if (first->get_count(first) == 0 && second->get_count(second) == 0)
 211         {
 212                 *add = FALSE;
 213                 return TRUE;
 214         }
 215
 216         first_iter = first->create_iterator(first, TRUE);
 217         second_iter = second->create_iterator(second, TRUE);
 218         /* compare algs, order of algs in "first" is preferred */
 219         while (first_iter->iterate(first_iter, (void**)&first_alg))
 220         {
 221                 second_iter->reset(second_iter);
 222                 while (second_iter->iterate(second_iter, (void**)&second_alg))
 223                 {
 224                         if (first_alg->algorithm == second_alg->algorithm &&
 225                                 first_alg->key_size == second_alg->key_size)
 226                         {
 227                                 /* ok, we have an algorithm */
 228                                 *alg = first_alg->algorithm;
 229                                 *key_size = first_alg->key_size;
 230                                 *add = TRUE;
 231                                 first_iter->destroy(first_iter);
 232                                 second_iter->destroy(second_iter);
 233                                 return TRUE;
 234                         }
 235                 }
 236         }
 237         /* no match in all comparisons */
 238         first_iter->destroy(first_iter);
 239         second_iter->destroy(second_iter);
 240         return FALSE;
 241 }
 242
 243 /**
 244  * Implements proposal_t.select.
 245  */
 246 static proposal_t *select_proposal(private_proposal_t *this, private_proposal_t *other)
 247 {
 248         proposal_t *selected;
 249         u_int16_t algo;
 250         size_t key_size;
 251         bool add;
 252
 253         /* check protocol */
 254         if (this->protocol != other->protocol)
 255         {
 256                 return NULL;
 257         }
 258
 259         selected = proposal_create(this->protocol);
 260
 261         /* select encryption algorithm */
 262         if (select_algo(this->encryption_algos, other->encryption_algos, &add, &algo, &key_size))
 263         {
 264                 if (add)
 265                 {
 266                         selected->add_algorithm(selected, ENCRYPTION_ALGORITHM, algo, key_size);
 267                 }
 268         }
 269         else
 270         {
 271                 selected->destroy(selected);
 272                 return NULL;
 273         }
 274         /* select integrity algorithm */
 275         if (select_algo(this->integrity_algos, other->integrity_algos, &add, &algo, &key_size))
 276         {
 277                 if (add)
 278                 {
 279                         selected->add_algorithm(selected, INTEGRITY_ALGORITHM, algo, key_size);
 280                 }
 281         }
 282         else
 283         {
 284                 selected->destroy(selected);
 285                 return NULL;
 286         }
 287         /* select prf algorithm */
 288         if (select_algo(this->prf_algos, other->prf_algos, &add, &algo, &key_size))
 289         {
 290                 if (add)
 291                 {
 292                         selected->add_algorithm(selected, PSEUDO_RANDOM_FUNCTION, algo, key_size);
 293                 }
 294         }
 295         else
 296         {
 297                 selected->destroy(selected);
 298                 return NULL;
 299         }
 300         /* select a DH-group */
 301         if (select_algo(this->dh_groups, other->dh_groups, &add, &algo, &key_size))
 302         {
 303                 if (add)
 304                 {
 305                         selected->add_algorithm(selected, DIFFIE_HELLMAN_GROUP, algo, 0);
 306                 }
 307         }
 308         else
 309         {
 310                 selected->destroy(selected);
 311                 return NULL;
 312         }
 313         /* select if we use ESNs */
 314         if (select_algo(this->esns, other->esns, &add, &algo, &key_size))
 315         {
 316                 if (add)
 317                 {
 318                         selected->add_algorithm(selected, EXTENDED_SEQUENCE_NUMBERS, algo, 0);
 319                 }
 320         }
 321         else
 322         {
 323                 selected->destroy(selected);
 324                 return NULL;
 325         }
 326
 327         /* apply SPI from "other" */
 328         selected->set_spi(selected, other->spi);
 329
 330         /* everything matched, return new proposal */
 331         return selected;
 332 }
 333
 334 /**
 335  * Implements proposal_t.get_protocols.
 336  */
 337 static protocol_id_t get_protocol(private_proposal_t *this)
 338 {
 339         return this->protocol;
 340 }
 341
 342 /**
 343  * Implements proposal_t.set_spi.
 344  */
 345 static void set_spi(private_proposal_t *this, u_int64_t spi)
 346 {
 347         this->spi = spi;
 348 }
 349
 350 /**
 351  * Implements proposal_t.get_spi.
 352  */
 353 static u_int64_t get_spi(private_proposal_t *this)
 354 {
 355         return this->spi;
 356 }
 357
 358 /**
 359  * Clone a algorithm list
 360  */
 361 static void clone_algo_list(linked_list_t *list, linked_list_t *clone_list)
 362 {
 363         algorithm_t *algo, *clone_algo;
 364         iterator_t *iterator = list->create_iterator(list, TRUE);
 365         while (iterator->iterate(iterator, (void**)&algo))
 366         {
 367                 clone_algo = malloc_thing(algorithm_t);
 368                 memcpy(clone_algo, algo, sizeof(algorithm_t));
 369                 clone_list->insert_last(clone_list, (void*)clone_algo);
 370         }
 371         iterator->destroy(iterator);
 372 }
 373
 374 /**
 375  * Implements proposal_t.clone
 376  */
 377 static proposal_t *clone_(private_proposal_t *this)
 378 {
 379         private_proposal_t *clone = (private_proposal_t*)proposal_create(this->protocol);
 380
 381         clone_algo_list(this->encryption_algos, clone->encryption_algos);
 382         clone_algo_list(this->integrity_algos, clone->integrity_algos);
 383         clone_algo_list(this->prf_algos, clone->prf_algos);
 384         clone_algo_list(this->dh_groups, clone->dh_groups);
 385         clone_algo_list(this->esns, clone->esns);
 386
 387         clone->spi = this->spi;
 388
 389         return &clone->public;
 390 }
 391
 392 static status_t add_string_algo(private_proposal_t *this, chunk_t alg)
 393 {
 394         if (strncmp(alg.ptr, "null", alg.len) == 0)
 395         {
 396                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_NULL, 0);
 397         }
 398         else if (strncmp(alg.ptr, "aes128", alg.len) == 0)
 399         {
 400                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 128);
 401         }
 402         else if (strncmp(alg.ptr, "aes192", alg.len) == 0)
 403         {
 404                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 192);
 405         }
 406         else if (strncmp(alg.ptr, "aes256", alg.len) == 0)
 407         {
 408                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 256);
 409         }
 410         else if (strncmp(alg.ptr, "3des", alg.len) == 0)
 411         {
 412                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_3DES, 0);
 413         }
 414         /* blowfish only uses some predefined key sizes yet */
 415         else if (strncmp(alg.ptr, "blowfish128", alg.len) == 0)
 416         {
 417                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_BLOWFISH, 128);
 418         }
 419         else if (strncmp(alg.ptr, "blowfish192", alg.len) == 0)
 420         {
 421                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_BLOWFISH, 192);
 422         }
 423         else if (strncmp(alg.ptr, "blowfish256", alg.len) == 0)
 424         {
 425                 add_algorithm(this, ENCRYPTION_ALGORITHM, ENCR_BLOWFISH, 256);
 426         }
 427         else if (strncmp(alg.ptr, "sha", alg.len) == 0 ||
 428                          strncmp(alg.ptr, "sha1", alg.len) == 0)
 429         {
 430                 /* sha means we use SHA for both, PRF and AUTH */
 431                 add_algorithm(this, INTEGRITY_ALGORITHM, AUTH_HMAC_SHA1_96, 0);
 432                 if (this->protocol == PROTO_IKE)
 433                 {
 434                         add_algorithm(this, PSEUDO_RANDOM_FUNCTION, PRF_HMAC_SHA1, 0);
 435                 }
 436         }
 437         else if (strncmp(alg.ptr, "md5", alg.len) == 0)
 438         {
 439                 /* same for MD5 */
 440                 add_algorithm(this, INTEGRITY_ALGORITHM, AUTH_HMAC_MD5_96, 0);
 441                 if (this->protocol == PROTO_IKE)
 442                 {
 443                         add_algorithm(this, PSEUDO_RANDOM_FUNCTION, PRF_HMAC_MD5, 0);
 444                 }
 445         }
 446         else if (strncmp(alg.ptr, "modp1024", alg.len) == 0)
 447         {
 448                 add_algorithm(this, DIFFIE_HELLMAN_GROUP, MODP_1024_BIT, 0);
 449         }
 450         else if (strncmp(alg.ptr, "modp1536", alg.len) == 0)
 451         {
 452                 add_algorithm(this, DIFFIE_HELLMAN_GROUP, MODP_1536_BIT, 0);
 453         }
 454         else if (strncmp(alg.ptr, "modp2048", alg.len) == 0)
 455         {
 456                 add_algorithm(this, DIFFIE_HELLMAN_GROUP, MODP_2048_BIT, 0);
 457         }
 458         else if (strncmp(alg.ptr, "modp4096", alg.len) == 0)
 459         {
 460                 add_algorithm(this, DIFFIE_HELLMAN_GROUP, MODP_4096_BIT, 0);
 461         }
 462         else if (strncmp(alg.ptr, "modp8192", alg.len) == 0)
 463         {
 464                 add_algorithm(this, DIFFIE_HELLMAN_GROUP, MODP_8192_BIT, 0);
 465         }
 466         else
 467         {
 468                 return FAILED;
 469         }
 470         return SUCCESS;
 471 }
 472
 473 /**
 474  * Implements proposal_t.destroy.
 475  */
 476 static void destroy(private_proposal_t *this)
 477 {
 478         this->encryption_algos->destroy_function(this->encryption_algos, free);
 479         this->integrity_algos->destroy_function(this->integrity_algos, free);
 480         this->prf_algos->destroy_function(this->prf_algos, free);
 481         this->dh_groups->destroy_function(this->dh_groups, free);
 482         this->esns->destroy_function(this->esns, free);
 483         free(this);
 484 }
 485
 486 /*
 487  * Describtion in header-file
 488  */
 489 proposal_t *proposal_create(protocol_id_t protocol)
 490 {
 491         private_proposal_t *this = malloc_thing(private_proposal_t);
 492
 493         this->public.add_algorithm = (void (*)(proposal_t*,transform_type_t,u_int16_t,size_t))add_algorithm;
 494         this->public.create_algorithm_iterator = (iterator_t* (*)(proposal_t*,transform_type_t))create_algorithm_iterator;
 495         this->public.get_algorithm = (bool (*)(proposal_t*,transform_type_t,algorithm_t**))get_algorithm;
 496         this->public.select = (proposal_t* (*)(proposal_t*,proposal_t*))select_proposal;
 497         this->public.get_protocol = (protocol_id_t(*)(proposal_t*))get_protocol;
 498         this->public.set_spi = (void(*)(proposal_t*,u_int64_t))set_spi;
 499         this->public.get_spi = (u_int64_t(*)(proposal_t*))get_spi;
 500         this->public.clone = (proposal_t*(*)(proposal_t*))clone_;
 501         this->public.destroy = (void(*)(proposal_t*))destroy;
 502
 503         this->spi = 0;
 504         this->protocol = protocol;
 505
 506         this->encryption_algos = linked_list_create();
 507         this->integrity_algos = linked_list_create();
 508         this->prf_algos = linked_list_create();
 509         this->dh_groups = linked_list_create();
 510         this->esns = linked_list_create();
 511
 512         return &this->public;
 513 }
 514
 515 /*
 516  * Describtion in header-file
 517  */
 518 proposal_t *proposal_create_default(protocol_id_t protocol)
 519 {
 520         private_proposal_t *this = (private_proposal_t*)proposal_create(protocol);
 521
 522         switch (protocol)
 523         {
 524                 case PROTO_IKE:
 525                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_AES_CBC,    128);
 526                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_3DES,         0);
 527                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_SHA1_96, 0);
 528                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_MD5_96,  0);
 529                         add_algorithm(this, PSEUDO_RANDOM_FUNCTION, PRF_HMAC_SHA1,     0);
 530                         add_algorithm(this, PSEUDO_RANDOM_FUNCTION, PRF_HMAC_MD5,      0);
 531                         add_algorithm(this, DIFFIE_HELLMAN_GROUP,   MODP_2048_BIT,     0);
 532                         add_algorithm(this, DIFFIE_HELLMAN_GROUP,   MODP_1536_BIT,     0);
 533                         add_algorithm(this, DIFFIE_HELLMAN_GROUP,   MODP_1024_BIT,     0);
 534                         add_algorithm(this, DIFFIE_HELLMAN_GROUP,   MODP_4096_BIT,     0);
 535                         add_algorithm(this, DIFFIE_HELLMAN_GROUP,   MODP_8192_BIT,     0);
 536                         break;
 537                 case PROTO_ESP:
 538                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_AES_CBC,    128);
 539                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_AES_CBC,    192);
 540                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_AES_CBC,    256);
 541                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_3DES,         0);
 542                         add_algorithm(this, ENCRYPTION_ALGORITHM,   ENCR_BLOWFISH,   256);
 543                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_SHA1_96, 0);
 544                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_MD5_96,  0);
 545                         add_algorithm(this, EXTENDED_SEQUENCE_NUMBERS, NO_EXT_SEQ_NUMBERS, 0);
 546                         break;
 547                 case PROTO_AH:
 548                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_SHA1_96, 0);
 549                         add_algorithm(this, INTEGRITY_ALGORITHM,    AUTH_HMAC_MD5_96,  0);
 550                         add_algorithm(this, EXTENDED_SEQUENCE_NUMBERS, NO_EXT_SEQ_NUMBERS, 0);
 551                         break;
 552                 default:
 553                         break;
 554         }
 555
 556         return &this->public;
 557 }
 558
 559 /*
 560  * Describtion in header-file
 561  */
 562 proposal_t *proposal_create_from_string(protocol_id_t protocol, const char *algs)
 563 {
 564         private_proposal_t *this = (private_proposal_t*)proposal_create(protocol);
 565         chunk_t string = {(void*)algs, strlen(algs)};
 566         chunk_t alg;
 567         status_t status = SUCCESS;
 568
 569         eat_whitespace(&string);
 570         if (string.len < 1)
 571         {
 572                 destroy(this);
 573                 return NULL;
 574         }
 575
 576         /* get all tokens, separated by '-' */
 577         while (extract_token(&alg, '-', &string))
 578         {
 579                 status |= add_string_algo(this, alg);
 580         }
 581         if (string.len)
 582         {
 583                 status |= add_string_algo(this, string);
 584         }
 585         if (status != SUCCESS)
 586         {
 587                 destroy(this);
 588                 return NULL;
 589         }
 590
 591         if (protocol == PROTO_AH || protocol == PROTO_ESP)
 592         {
 593                 add_algorithm(this, EXTENDED_SEQUENCE_NUMBERS, NO_EXT_SEQ_NUMBERS, 0);
 594         }
 595         return &this->public;
 596 }