dbus-auth.c revision 169238e99a4a163c89eb053250daeedf5f73e5cd
1/* -*- mode: C; c-file-style: "gnu" -*- */ 2/* dbus-auth.c Authentication 3 * 4 * Copyright (C) 2002, 2003 Red Hat Inc. 5 * 6 * Licensed under the Academic Free License version 1.2 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23#include "dbus-auth.h" 24#include "dbus-string.h" 25#include "dbus-list.h" 26#include "dbus-internals.h" 27#include "dbus-keyring.h" 28#include "dbus-sha.h" 29 30/* See doc/dbus-sasl-profile.txt */ 31 32/** 33 * @defgroup DBusAuth Authentication 34 * @ingroup DBusInternals 35 * @brief DBusAuth object 36 * 37 * DBusAuth manages the authentication negotiation when a connection 38 * is first established, and also manage any encryption used over a 39 * connection. 40 * 41 * The file doc/dbus-sasl-profile.txt documents the network protocol 42 * used for authentication. 43 * 44 * @todo some SASL profiles require sending the empty string as a 45 * challenge/response, but we don't currently allow that in our 46 * protocol. 47 * 48 * @todo DBusAuth really needs to be rewritten as an explicit state 49 * machine. Right now it's too hard to prove to yourself by inspection 50 * that it works. 51 * 52 * @todo right now sometimes both ends will block waiting for input 53 * from the other end, e.g. if there's an error during 54 * DBUS_COOKIE_SHA1. 55 * 56 * @todo the cookie keyring needs to be cached globally not just 57 * per-auth (which raises threadsafety issues too) 58 * 59 * @todo grep FIXME in dbus-auth.c 60 */ 61 62/** 63 * @defgroup DBusAuthInternals Authentication implementation details 64 * @ingroup DBusInternals 65 * @brief DBusAuth implementation details 66 * 67 * Private details of authentication code. 68 * 69 * @{ 70 */ 71 72/** 73 * Processes a command. Returns whether we had enough memory to 74 * complete the operation. 75 */ 76typedef dbus_bool_t (* DBusProcessAuthCommandFunction) (DBusAuth *auth, 77 const DBusString *command, 78 const DBusString *args); 79 80typedef struct 81{ 82 const char *command; 83 DBusProcessAuthCommandFunction func; 84} DBusAuthCommandHandler; 85 86/** 87 * This function appends an initial client response to the given string 88 */ 89typedef dbus_bool_t (* DBusInitialResponseFunction) (DBusAuth *auth, 90 DBusString *response); 91 92/** 93 * This function processes a block of data received from the peer. 94 * i.e. handles a DATA command. 95 */ 96typedef dbus_bool_t (* DBusAuthDataFunction) (DBusAuth *auth, 97 const DBusString *data); 98 99/** 100 * This function encodes a block of data from the peer. 101 */ 102typedef dbus_bool_t (* DBusAuthEncodeFunction) (DBusAuth *auth, 103 const DBusString *data, 104 DBusString *encoded); 105 106/** 107 * This function decodes a block of data from the peer. 108 */ 109typedef dbus_bool_t (* DBusAuthDecodeFunction) (DBusAuth *auth, 110 const DBusString *data, 111 DBusString *decoded); 112 113/** 114 * This function is called when the mechanism is abandoned. 115 */ 116typedef void (* DBusAuthShutdownFunction) (DBusAuth *auth); 117 118typedef struct 119{ 120 const char *mechanism; 121 DBusAuthDataFunction server_data_func; 122 DBusAuthEncodeFunction server_encode_func; 123 DBusAuthDecodeFunction server_decode_func; 124 DBusAuthShutdownFunction server_shutdown_func; 125 DBusInitialResponseFunction client_initial_response_func; 126 DBusAuthDataFunction client_data_func; 127 DBusAuthEncodeFunction client_encode_func; 128 DBusAuthDecodeFunction client_decode_func; 129 DBusAuthShutdownFunction client_shutdown_func; 130} DBusAuthMechanismHandler; 131 132/** 133 * Internal members of DBusAuth. 134 */ 135struct DBusAuth 136{ 137 int refcount; /**< reference count */ 138 139 DBusString incoming; /**< Incoming data buffer */ 140 DBusString outgoing; /**< Outgoing data buffer */ 141 142 const DBusAuthCommandHandler *handlers; /**< Handlers for commands */ 143 144 const DBusAuthMechanismHandler *mech; /**< Current auth mechanism */ 145 146 DBusString identity; /**< Current identity we're authorizing 147 * as. 148 */ 149 150 DBusCredentials credentials; /**< Credentials read from socket, 151 * fields may be -1 152 */ 153 154 DBusCredentials authorized_identity; /**< Credentials that are authorized */ 155 156 DBusCredentials desired_identity; /**< Identity client has requested */ 157 158 DBusString context; /**< Cookie scope */ 159 DBusKeyring *keyring; /**< Keyring for cookie mechanism. */ 160 int cookie_id; /**< ID of cookie to use */ 161 DBusString challenge; /**< Challenge sent to client */ 162 163 unsigned int needed_memory : 1; /**< We needed memory to continue since last 164 * successful getting something done 165 */ 166 unsigned int need_disconnect : 1; /**< We've given up, time to disconnect */ 167 unsigned int authenticated : 1; /**< We are authenticated */ 168 unsigned int authenticated_pending_output : 1; /**< Authenticated once we clear outgoing buffer */ 169 unsigned int authenticated_pending_begin : 1; /**< Authenticated once we get BEGIN */ 170 unsigned int already_got_mechanisms : 1; /**< Client already got mech list */ 171 unsigned int already_asked_for_initial_response : 1; /**< Already sent a blank challenge to get an initial response */ 172}; 173 174typedef struct 175{ 176 DBusAuth base; 177 178 DBusList *mechs_to_try; /**< Mechanisms we got from the server that we're going to try using */ 179 180} DBusAuthClient; 181 182typedef struct 183{ 184 DBusAuth base; 185 186 int failures; /**< Number of times client has been rejected */ 187 int max_failures; /**< Number of times we reject before disconnect */ 188 189} DBusAuthServer; 190 191static dbus_bool_t process_auth (DBusAuth *auth, 192 const DBusString *command, 193 const DBusString *args); 194static dbus_bool_t process_cancel (DBusAuth *auth, 195 const DBusString *command, 196 const DBusString *args); 197static dbus_bool_t process_begin (DBusAuth *auth, 198 const DBusString *command, 199 const DBusString *args); 200static dbus_bool_t process_data_server (DBusAuth *auth, 201 const DBusString *command, 202 const DBusString *args); 203static dbus_bool_t process_error_server (DBusAuth *auth, 204 const DBusString *command, 205 const DBusString *args); 206static dbus_bool_t process_rejected (DBusAuth *auth, 207 const DBusString *command, 208 const DBusString *args); 209static dbus_bool_t process_ok (DBusAuth *auth, 210 const DBusString *command, 211 const DBusString *args); 212static dbus_bool_t process_data_client (DBusAuth *auth, 213 const DBusString *command, 214 const DBusString *args); 215static dbus_bool_t process_error_client (DBusAuth *auth, 216 const DBusString *command, 217 const DBusString *args); 218 219 220static dbus_bool_t client_try_next_mechanism (DBusAuth *auth); 221static dbus_bool_t send_rejected (DBusAuth *auth); 222 223static DBusAuthCommandHandler 224server_handlers[] = { 225 { "AUTH", process_auth }, 226 { "CANCEL", process_cancel }, 227 { "BEGIN", process_begin }, 228 { "DATA", process_data_server }, 229 { "ERROR", process_error_server }, 230 { NULL, NULL } 231}; 232 233static DBusAuthCommandHandler 234client_handlers[] = { 235 { "REJECTED", process_rejected }, 236 { "OK", process_ok }, 237 { "DATA", process_data_client }, 238 { "ERROR", process_error_client }, 239 { NULL, NULL } 240}; 241 242/** 243 * @param auth the auth conversation 244 * @returns #TRUE if the conversation is the server side 245 */ 246#define DBUS_AUTH_IS_SERVER(auth) ((auth)->handlers == server_handlers) 247/** 248 * @param auth the auth conversation 249 * @returns #TRUE if the conversation is the client side 250 */ 251#define DBUS_AUTH_IS_CLIENT(auth) ((auth)->handlers == client_handlers) 252/** 253 * @param auth the auth conversation 254 * @returns auth cast to DBusAuthClient 255 */ 256#define DBUS_AUTH_CLIENT(auth) ((DBusAuthClient*)(auth)) 257/** 258 * @param auth the auth conversation 259 * @returns auth cast to DBusAuthServer 260 */ 261#define DBUS_AUTH_SERVER(auth) ((DBusAuthServer*)(auth)) 262 263static DBusAuth* 264_dbus_auth_new (int size) 265{ 266 DBusAuth *auth; 267 268 auth = dbus_malloc0 (size); 269 if (auth == NULL) 270 return NULL; 271 272 auth->refcount = 1; 273 274 auth->credentials.pid = -1; 275 auth->credentials.uid = -1; 276 auth->credentials.gid = -1; 277 278 auth->authorized_identity.pid = -1; 279 auth->authorized_identity.uid = -1; 280 auth->authorized_identity.gid = -1; 281 282 auth->desired_identity.pid = -1; 283 auth->desired_identity.uid = -1; 284 auth->desired_identity.gid = -1; 285 286 auth->keyring = NULL; 287 auth->cookie_id = -1; 288 289 /* note that we don't use the max string length feature, 290 * because you can't use that feature if you're going to 291 * try to recover from out-of-memory (it creates 292 * what looks like unrecoverable inability to alloc 293 * more space in the string). But we do handle 294 * overlong buffers in _dbus_auth_do_work(). 295 */ 296 297 if (!_dbus_string_init (&auth->incoming, _DBUS_INT_MAX)) 298 goto enomem_0; 299 300 if (!_dbus_string_init (&auth->outgoing, _DBUS_INT_MAX)) 301 goto enomem_1; 302 303 if (!_dbus_string_init (&auth->identity, _DBUS_INT_MAX)) 304 goto enomem_2; 305 306 if (!_dbus_string_init (&auth->context, _DBUS_INT_MAX)) 307 goto enomem_3; 308 309 if (!_dbus_string_init (&auth->challenge, _DBUS_INT_MAX)) 310 goto enomem_4; 311 312 /* default context if none is specified */ 313 if (!_dbus_string_append (&auth->context, "org_freedesktop_general")) 314 goto enomem_5; 315 316 return auth; 317 318 enomem_5: 319 _dbus_string_free (&auth->challenge); 320 enomem_4: 321 _dbus_string_free (&auth->context); 322 enomem_3: 323 _dbus_string_free (&auth->identity); 324 enomem_2: 325 _dbus_string_free (&auth->incoming); 326 enomem_1: 327 _dbus_string_free (&auth->outgoing); 328 enomem_0: 329 dbus_free (auth); 330 return NULL; 331} 332 333static void 334shutdown_mech (DBusAuth *auth) 335{ 336 /* Cancel any auth */ 337 auth->authenticated_pending_begin = FALSE; 338 auth->authenticated = FALSE; 339 auth->already_asked_for_initial_response = FALSE; 340 _dbus_string_set_length (&auth->identity, 0); 341 342 auth->authorized_identity.pid = -1; 343 auth->authorized_identity.uid = -1; 344 auth->authorized_identity.gid = -1; 345 346 auth->desired_identity.pid = -1; 347 auth->desired_identity.uid = -1; 348 auth->desired_identity.gid = -1; 349 350 if (auth->mech != NULL) 351 { 352 _dbus_verbose ("Shutting down mechanism %s\n", 353 auth->mech->mechanism); 354 355 if (DBUS_AUTH_IS_CLIENT (auth)) 356 (* auth->mech->client_shutdown_func) (auth); 357 else 358 (* auth->mech->server_shutdown_func) (auth); 359 360 auth->mech = NULL; 361 } 362} 363 364/* Returns TRUE but with an empty string hash if the 365 * cookie_id isn't known. As with all this code 366 * TRUE just means we had enough memory. 367 */ 368static dbus_bool_t 369sha1_compute_hash (DBusAuth *auth, 370 int cookie_id, 371 const DBusString *server_challenge, 372 const DBusString *client_challenge, 373 DBusString *hash) 374{ 375 DBusString cookie; 376 DBusString to_hash; 377 dbus_bool_t retval; 378 379 _dbus_assert (auth->keyring != NULL); 380 381 retval = FALSE; 382 383 if (!_dbus_string_init (&cookie, _DBUS_INT_MAX)) 384 return FALSE; 385 386 if (!_dbus_keyring_get_hex_key (auth->keyring, cookie_id, 387 &cookie)) 388 goto out_0; 389 390 if (_dbus_string_get_length (&cookie) == 0) 391 { 392 retval = TRUE; 393 goto out_0; 394 } 395 396 if (!_dbus_string_init (&to_hash, _DBUS_INT_MAX)) 397 goto out_0; 398 399 if (!_dbus_string_copy (server_challenge, 0, 400 &to_hash, _dbus_string_get_length (&to_hash))) 401 goto out_1; 402 403 if (!_dbus_string_append (&to_hash, ":")) 404 goto out_1; 405 406 if (!_dbus_string_copy (client_challenge, 0, 407 &to_hash, _dbus_string_get_length (&to_hash))) 408 goto out_1; 409 410 if (!_dbus_string_append (&to_hash, ":")) 411 goto out_1; 412 413 if (!_dbus_string_copy (&cookie, 0, 414 &to_hash, _dbus_string_get_length (&to_hash))) 415 goto out_1; 416 417 if (!_dbus_sha_compute (&to_hash, hash)) 418 goto out_1; 419 420 retval = TRUE; 421 422 out_1: 423 _dbus_string_zero (&to_hash); 424 _dbus_string_free (&to_hash); 425 out_0: 426 _dbus_string_zero (&cookie); 427 _dbus_string_free (&cookie); 428 return retval; 429} 430 431/** http://www.ietf.org/rfc/rfc2831.txt suggests at least 64 bits of 432 * entropy, we use 128. This is the number of bytes in the random 433 * challenge. 434 */ 435#define N_CHALLENGE_BYTES (128/8) 436 437static dbus_bool_t 438sha1_handle_first_client_response (DBusAuth *auth, 439 const DBusString *data) 440{ 441 /* We haven't sent a challenge yet, we're expecting a desired 442 * username from the client. 443 */ 444 DBusString tmp; 445 DBusString tmp2; 446 dbus_bool_t retval; 447 int old_len; 448 DBusError error; 449 450 retval = FALSE; 451 452 _dbus_string_set_length (&auth->challenge, 0); 453 454 if (_dbus_string_get_length (data) > 0) 455 { 456 if (_dbus_string_get_length (&auth->identity) > 0) 457 { 458 /* Tried to send two auth identities, wtf */ 459 _dbus_verbose ("client tried to send auth identity, but we already have one\n"); 460 return send_rejected (auth); 461 } 462 else 463 { 464 /* this is our auth identity */ 465 if (!_dbus_string_copy (data, 0, &auth->identity, 0)) 466 return FALSE; 467 } 468 } 469 470 if (!_dbus_credentials_from_username (data, &auth->desired_identity)) 471 { 472 _dbus_verbose ("Did not get a valid username from client\n"); 473 return send_rejected (auth); 474 } 475 476 if (!_dbus_string_init (&tmp, _DBUS_INT_MAX)) 477 return FALSE; 478 479 if (!_dbus_string_init (&tmp2, _DBUS_INT_MAX)) 480 { 481 _dbus_string_free (&tmp); 482 return FALSE; 483 } 484 485 old_len = _dbus_string_get_length (&auth->outgoing); 486 487 /* we cache the keyring for speed, so here we drop it if it's the 488 * wrong one. FIXME caching the keyring here is useless since we use 489 * a different DBusAuth for every connection. 490 */ 491 if (auth->keyring && 492 !_dbus_keyring_is_for_user (auth->keyring, 493 data)) 494 { 495 _dbus_keyring_unref (auth->keyring); 496 auth->keyring = NULL; 497 } 498 499 if (auth->keyring == NULL) 500 { 501 DBusError error; 502 503 dbus_error_init (&error); 504 auth->keyring = _dbus_keyring_new_homedir (data, 505 &auth->context, 506 &error); 507 508 if (auth->keyring == NULL) 509 { 510 if (dbus_error_has_name (&error, 511 DBUS_ERROR_NO_MEMORY)) 512 { 513 dbus_error_free (&error); 514 goto out; 515 } 516 else 517 { 518 _DBUS_ASSERT_ERROR_IS_SET (&error); 519 _dbus_verbose ("Error loading keyring: %s\n", 520 error.message); 521 if (send_rejected (auth)) 522 retval = TRUE; /* retval is only about mem */ 523 dbus_error_free (&error); 524 goto out; 525 } 526 } 527 else 528 { 529 _dbus_assert (!dbus_error_is_set (&error)); 530 } 531 } 532 533 _dbus_assert (auth->keyring != NULL); 534 535 dbus_error_init (&error); 536 auth->cookie_id = _dbus_keyring_get_best_key (auth->keyring, &error); 537 if (auth->cookie_id < 0) 538 { 539 _DBUS_ASSERT_ERROR_IS_SET (&error); 540 _dbus_verbose ("Could not get a cookie ID to send to client: %s\n", 541 error.message); 542 if (send_rejected (auth)) 543 retval = TRUE; 544 dbus_error_free (&error); 545 goto out; 546 } 547 else 548 { 549 _dbus_assert (!dbus_error_is_set (&error)); 550 } 551 552 if (!_dbus_string_copy (&auth->context, 0, 553 &tmp2, _dbus_string_get_length (&tmp2))) 554 goto out; 555 556 if (!_dbus_string_append (&tmp2, " ")) 557 goto out; 558 559 if (!_dbus_string_append_int (&tmp2, auth->cookie_id)) 560 goto out; 561 562 if (!_dbus_string_append (&tmp2, " ")) 563 goto out; 564 565 if (!_dbus_generate_random_bytes (&tmp, N_CHALLENGE_BYTES)) 566 goto out; 567 568 _dbus_string_set_length (&auth->challenge, 0); 569 if (!_dbus_string_hex_encode (&tmp, 0, &auth->challenge, 0)) 570 goto out; 571 572 if (!_dbus_string_hex_encode (&tmp, 0, &tmp2, 573 _dbus_string_get_length (&tmp2))) 574 goto out; 575 576 if (!_dbus_string_append (&auth->outgoing, 577 "DATA ")) 578 goto out; 579 580 if (!_dbus_string_base64_encode (&tmp2, 0, &auth->outgoing, 581 _dbus_string_get_length (&auth->outgoing))) 582 goto out; 583 584 if (!_dbus_string_append (&auth->outgoing, 585 "\r\n")) 586 goto out; 587 588 retval = TRUE; 589 590 out: 591 _dbus_string_zero (&tmp); 592 _dbus_string_free (&tmp); 593 _dbus_string_zero (&tmp2); 594 _dbus_string_free (&tmp2); 595 if (!retval) 596 _dbus_string_set_length (&auth->outgoing, old_len); 597 return retval; 598} 599 600static dbus_bool_t 601sha1_handle_second_client_response (DBusAuth *auth, 602 const DBusString *data) 603{ 604 /* We are expecting a response which is the hex-encoded client 605 * challenge, space, then SHA-1 hash of the concatenation of our 606 * challenge, ":", client challenge, ":", secret key, all 607 * hex-encoded. 608 */ 609 int i; 610 DBusString client_challenge; 611 DBusString client_hash; 612 dbus_bool_t retval; 613 DBusString correct_hash; 614 615 retval = FALSE; 616 617 if (!_dbus_string_find_blank (data, 0, &i)) 618 { 619 _dbus_verbose ("no space separator in client response\n"); 620 return send_rejected (auth); 621 } 622 623 if (!_dbus_string_init (&client_challenge, _DBUS_INT_MAX)) 624 goto out_0; 625 626 if (!_dbus_string_init (&client_hash, _DBUS_INT_MAX)) 627 goto out_1; 628 629 if (!_dbus_string_copy_len (data, 0, i, &client_challenge, 630 0)) 631 goto out_2; 632 633 _dbus_string_skip_blank (data, i, &i); 634 635 if (!_dbus_string_copy_len (data, i, 636 _dbus_string_get_length (data) - i, 637 &client_hash, 638 0)) 639 goto out_2; 640 641 if (_dbus_string_get_length (&client_challenge) == 0 || 642 _dbus_string_get_length (&client_hash) == 0) 643 { 644 _dbus_verbose ("zero-length client challenge or hash\n"); 645 if (send_rejected (auth)) 646 retval = TRUE; 647 goto out_2; 648 } 649 650 if (!_dbus_string_init (&correct_hash, _DBUS_INT_MAX)) 651 goto out_2; 652 653 if (!sha1_compute_hash (auth, auth->cookie_id, 654 &auth->challenge, 655 &client_challenge, 656 &correct_hash)) 657 goto out_3; 658 659 /* if cookie_id was invalid, then we get an empty hash */ 660 if (_dbus_string_get_length (&correct_hash) == 0) 661 { 662 if (send_rejected (auth)) 663 retval = TRUE; 664 goto out_3; 665 } 666 667 if (!_dbus_string_equal (&client_hash, &correct_hash)) 668 { 669 if (send_rejected (auth)) 670 retval = TRUE; 671 goto out_3; 672 } 673 674 if (!_dbus_string_append (&auth->outgoing, 675 "OK\r\n")) 676 goto out_3; 677 678 _dbus_verbose ("authenticated client with UID %d using DBUS_COOKIE_SHA1\n", 679 auth->desired_identity.uid); 680 681 auth->authorized_identity = auth->desired_identity; 682 auth->authenticated_pending_begin = TRUE; 683 retval = TRUE; 684 685 out_3: 686 _dbus_string_zero (&correct_hash); 687 _dbus_string_free (&correct_hash); 688 out_2: 689 _dbus_string_zero (&client_hash); 690 _dbus_string_free (&client_hash); 691 out_1: 692 _dbus_string_free (&client_challenge); 693 out_0: 694 return retval; 695} 696 697static dbus_bool_t 698handle_server_data_cookie_sha1_mech (DBusAuth *auth, 699 const DBusString *data) 700{ 701 if (auth->cookie_id < 0) 702 return sha1_handle_first_client_response (auth, data); 703 else 704 return sha1_handle_second_client_response (auth, data); 705} 706 707static void 708handle_server_shutdown_cookie_sha1_mech (DBusAuth *auth) 709{ 710 auth->cookie_id = -1; 711 _dbus_string_set_length (&auth->challenge, 0); 712} 713 714static dbus_bool_t 715handle_client_initial_response_cookie_sha1_mech (DBusAuth *auth, 716 DBusString *response) 717{ 718 const DBusString *username; 719 dbus_bool_t retval; 720 721 retval = FALSE; 722 723 if (!_dbus_user_info_from_current_process (&username, 724 NULL, NULL)) 725 goto out_0; 726 727 if (!_dbus_string_base64_encode (username, 0, 728 response, 729 _dbus_string_get_length (response))) 730 goto out_0; 731 732 retval = TRUE; 733 734 out_0: 735 return retval; 736} 737 738/* FIXME if we send the server an error, right now both sides 739 * just hang. Server has to reject on getting an error, or 740 * client has to cancel. Should be in the spec. 741 */ 742static dbus_bool_t 743handle_client_data_cookie_sha1_mech (DBusAuth *auth, 744 const DBusString *data) 745{ 746 /* The data we get from the server should be the cookie context 747 * name, the cookie ID, and the server challenge, separated by 748 * spaces. We send back our challenge string and the correct hash. 749 */ 750 dbus_bool_t retval; 751 DBusString context; 752 DBusString cookie_id_str; 753 DBusString server_challenge; 754 DBusString client_challenge; 755 DBusString correct_hash; 756 DBusString tmp; 757 int i, j; 758 long val; 759 int old_len; 760 761 retval = FALSE; 762 763 if (!_dbus_string_find_blank (data, 0, &i)) 764 { 765 if (_dbus_string_append (&auth->outgoing, 766 "ERROR \"Server did not send context/ID/challenge properly\"\r\n")) 767 retval = TRUE; 768 goto out_0; 769 } 770 771 if (!_dbus_string_init (&context, _DBUS_INT_MAX)) 772 goto out_0; 773 774 if (!_dbus_string_copy_len (data, 0, i, 775 &context, 0)) 776 goto out_1; 777 778 _dbus_string_skip_blank (data, i, &i); 779 if (!_dbus_string_find_blank (data, i, &j)) 780 { 781 if (_dbus_string_append (&auth->outgoing, 782 "ERROR \"Server did not send context/ID/challenge properly\"\r\n")) 783 retval = TRUE; 784 goto out_1; 785 } 786 787 if (!_dbus_string_init (&cookie_id_str, _DBUS_INT_MAX)) 788 goto out_1; 789 790 if (!_dbus_string_copy_len (data, i, j - i, 791 &cookie_id_str, 0)) 792 goto out_2; 793 794 if (!_dbus_string_init (&server_challenge, _DBUS_INT_MAX)) 795 goto out_2; 796 797 i = j; 798 _dbus_string_skip_blank (data, i, &i); 799 j = _dbus_string_get_length (data); 800 801 if (!_dbus_string_copy_len (data, i, j - i, 802 &server_challenge, 0)) 803 goto out_3; 804 805 if (!_dbus_keyring_validate_context (&context)) 806 { 807 if (_dbus_string_append (&auth->outgoing, 808 "ERROR \"Server sent invalid cookie context\"\r\n")) 809 retval = TRUE; 810 goto out_3; 811 } 812 813 if (!_dbus_string_parse_int (&cookie_id_str, 0, &val, NULL)) 814 { 815 if (_dbus_string_append (&auth->outgoing, 816 "ERROR \"Could not parse cookie ID as an integer\"\r\n")) 817 retval = TRUE; 818 goto out_3; 819 } 820 821 if (_dbus_string_get_length (&server_challenge) == 0) 822 { 823 if (_dbus_string_append (&auth->outgoing, 824 "ERROR \"Empty server challenge string\"\r\n")) 825 retval = TRUE; 826 goto out_3; 827 } 828 829 if (auth->keyring == NULL) 830 { 831 DBusError error; 832 833 dbus_error_init (&error); 834 auth->keyring = _dbus_keyring_new_homedir (NULL, 835 &context, 836 &error); 837 838 if (auth->keyring == NULL) 839 { 840 if (dbus_error_has_name (&error, 841 DBUS_ERROR_NO_MEMORY)) 842 { 843 dbus_error_free (&error); 844 goto out_3; 845 } 846 else 847 { 848 _DBUS_ASSERT_ERROR_IS_SET (&error); 849 850 _dbus_verbose ("Error loading keyring: %s\n", 851 error.message); 852 853 if (_dbus_string_append (&auth->outgoing, 854 "ERROR \"Could not load cookie file\"\r\n")) 855 retval = TRUE; /* retval is only about mem */ 856 857 dbus_error_free (&error); 858 goto out_3; 859 } 860 } 861 else 862 { 863 _dbus_assert (!dbus_error_is_set (&error)); 864 } 865 } 866 867 _dbus_assert (auth->keyring != NULL); 868 869 if (!_dbus_string_init (&tmp, _DBUS_INT_MAX)) 870 goto out_3; 871 872 if (!_dbus_generate_random_bytes (&tmp, N_CHALLENGE_BYTES)) 873 goto out_4; 874 875 if (!_dbus_string_init (&client_challenge, _DBUS_INT_MAX)) 876 goto out_4; 877 878 if (!_dbus_string_hex_encode (&tmp, 0, &client_challenge, 0)) 879 goto out_5; 880 881 if (!_dbus_string_init (&correct_hash, _DBUS_INT_MAX)) 882 goto out_6; 883 884 if (!sha1_compute_hash (auth, val, 885 &server_challenge, 886 &client_challenge, 887 &correct_hash)) 888 goto out_6; 889 890 if (_dbus_string_get_length (&correct_hash) == 0) 891 { 892 /* couldn't find the cookie ID or something */ 893 if (_dbus_string_append (&auth->outgoing, 894 "ERROR \"Don't have the requested cookie ID\"\r\n")) 895 retval = TRUE; 896 goto out_6; 897 } 898 899 _dbus_string_set_length (&tmp, 0); 900 901 if (!_dbus_string_copy (&client_challenge, 0, &tmp, 902 _dbus_string_get_length (&tmp))) 903 goto out_6; 904 905 if (!_dbus_string_append (&tmp, " ")) 906 goto out_6; 907 908 if (!_dbus_string_copy (&correct_hash, 0, &tmp, 909 _dbus_string_get_length (&tmp))) 910 goto out_6; 911 912 old_len = _dbus_string_get_length (&auth->outgoing); 913 if (!_dbus_string_append (&auth->outgoing, "DATA ")) 914 goto out_6; 915 916 if (!_dbus_string_base64_encode (&tmp, 0, 917 &auth->outgoing, 918 _dbus_string_get_length (&auth->outgoing))) 919 { 920 _dbus_string_set_length (&auth->outgoing, old_len); 921 goto out_6; 922 } 923 924 if (!_dbus_string_append (&auth->outgoing, "\r\n")) 925 { 926 _dbus_string_set_length (&auth->outgoing, old_len); 927 goto out_6; 928 } 929 930 retval = TRUE; 931 932 out_6: 933 _dbus_string_zero (&correct_hash); 934 _dbus_string_free (&correct_hash); 935 out_5: 936 _dbus_string_free (&client_challenge); 937 out_4: 938 _dbus_string_zero (&tmp); 939 _dbus_string_free (&tmp); 940 out_3: 941 _dbus_string_free (&server_challenge); 942 out_2: 943 _dbus_string_free (&cookie_id_str); 944 out_1: 945 _dbus_string_free (&context); 946 out_0: 947 return retval; 948} 949 950static void 951handle_client_shutdown_cookie_sha1_mech (DBusAuth *auth) 952{ 953 auth->cookie_id = -1; 954 _dbus_string_set_length (&auth->challenge, 0); 955} 956 957static dbus_bool_t 958handle_server_data_external_mech (DBusAuth *auth, 959 const DBusString *data) 960{ 961 if (auth->credentials.uid < 0) 962 { 963 _dbus_verbose ("no credentials, mechanism EXTERNAL can't authenticate\n"); 964 return send_rejected (auth); 965 } 966 967 if (_dbus_string_get_length (data) > 0) 968 { 969 if (_dbus_string_get_length (&auth->identity) > 0) 970 { 971 /* Tried to send two auth identities, wtf */ 972 _dbus_verbose ("client tried to send auth identity, but we already have one\n"); 973 return send_rejected (auth); 974 } 975 else 976 { 977 /* this is our auth identity */ 978 if (!_dbus_string_copy (data, 0, &auth->identity, 0)) 979 return FALSE; 980 } 981 } 982 983 /* Poke client for an auth identity, if none given */ 984 if (_dbus_string_get_length (&auth->identity) == 0 && 985 !auth->already_asked_for_initial_response) 986 { 987 if (_dbus_string_append (&auth->outgoing, 988 "DATA\r\n")) 989 { 990 _dbus_verbose ("sending empty challenge asking client for auth identity\n"); 991 auth->already_asked_for_initial_response = TRUE; 992 return TRUE; 993 } 994 else 995 return FALSE; 996 } 997 998 auth->desired_identity.pid = -1; 999 auth->desired_identity.uid = -1; 1000 auth->desired_identity.gid = -1; 1001 1002 /* If auth->identity is still empty here, then client 1003 * responded with an empty string after we poked it for 1004 * an initial response. This means to try to auth the 1005 * identity provided in the credentials. 1006 */ 1007 if (_dbus_string_get_length (&auth->identity) == 0) 1008 { 1009 auth->desired_identity.uid = auth->credentials.uid; 1010 } 1011 else 1012 { 1013 if (!_dbus_credentials_from_uid_string (&auth->identity, 1014 &auth->desired_identity)) 1015 { 1016 _dbus_verbose ("could not get credentials from uid string\n"); 1017 return send_rejected (auth); 1018 } 1019 } 1020 1021 if (auth->desired_identity.uid < 0) 1022 { 1023 _dbus_verbose ("desired UID %d is no good\n", auth->desired_identity.uid); 1024 return send_rejected (auth); 1025 } 1026 1027 if (_dbus_credentials_match (&auth->desired_identity, 1028 &auth->credentials)) 1029 { 1030 /* client has authenticated */ 1031 if (!_dbus_string_append (&auth->outgoing, 1032 "OK\r\n")) 1033 return FALSE; 1034 1035 _dbus_verbose ("authenticated client with UID %d matching socket credentials UID %d\n", 1036 auth->desired_identity.uid, 1037 auth->credentials.uid); 1038 1039 auth->authorized_identity.uid = auth->desired_identity.uid; 1040 1041 auth->authenticated_pending_begin = TRUE; 1042 1043 return TRUE; 1044 } 1045 else 1046 { 1047 _dbus_verbose ("credentials uid=%d gid=%d do not allow uid=%d gid=%d\n", 1048 auth->credentials.uid, auth->credentials.gid, 1049 auth->desired_identity.uid, auth->desired_identity.gid); 1050 return send_rejected (auth); 1051 } 1052} 1053 1054static void 1055handle_server_shutdown_external_mech (DBusAuth *auth) 1056{ 1057 1058} 1059 1060static dbus_bool_t 1061handle_client_initial_response_external_mech (DBusAuth *auth, 1062 DBusString *response) 1063{ 1064 /* We always append our UID as an initial response, so the server 1065 * doesn't have to send back an empty challenge to check whether we 1066 * want to specify an identity. i.e. this avoids a round trip that 1067 * the spec for the EXTERNAL mechanism otherwise requires. 1068 */ 1069 DBusString plaintext; 1070 1071 if (!_dbus_string_init (&plaintext, _DBUS_INT_MAX)) 1072 return FALSE; 1073 1074 if (!_dbus_string_append_our_uid (&plaintext)) 1075 goto failed; 1076 1077 if (!_dbus_string_base64_encode (&plaintext, 0, 1078 response, 1079 _dbus_string_get_length (response))) 1080 goto failed; 1081 1082 _dbus_string_free (&plaintext); 1083 1084 return TRUE; 1085 1086 failed: 1087 _dbus_string_free (&plaintext); 1088 return FALSE; 1089} 1090 1091static dbus_bool_t 1092handle_client_data_external_mech (DBusAuth *auth, 1093 const DBusString *data) 1094{ 1095 1096 return TRUE; 1097} 1098 1099static void 1100handle_client_shutdown_external_mech (DBusAuth *auth) 1101{ 1102 1103} 1104 1105/* Put mechanisms here in order of preference. 1106 * What I eventually want to have is: 1107 * 1108 * - a mechanism that checks UNIX domain socket credentials 1109 * - a simple magic cookie mechanism like X11 or ICE 1110 * - mechanisms that chain to Cyrus SASL, so we can use anything it 1111 * offers such as Kerberos, X509, whatever. 1112 * 1113 */ 1114static const DBusAuthMechanismHandler 1115all_mechanisms[] = { 1116 { "EXTERNAL", 1117 handle_server_data_external_mech, 1118 NULL, NULL, 1119 handle_server_shutdown_external_mech, 1120 handle_client_initial_response_external_mech, 1121 handle_client_data_external_mech, 1122 NULL, NULL, 1123 handle_client_shutdown_external_mech }, 1124 { "DBUS_COOKIE_SHA1", 1125 handle_server_data_cookie_sha1_mech, 1126 NULL, NULL, 1127 handle_server_shutdown_cookie_sha1_mech, 1128 handle_client_initial_response_cookie_sha1_mech, 1129 handle_client_data_cookie_sha1_mech, 1130 NULL, NULL, 1131 handle_client_shutdown_cookie_sha1_mech }, 1132 { NULL, NULL } 1133}; 1134 1135static const DBusAuthMechanismHandler* 1136find_mech (const DBusString *name) 1137{ 1138 int i; 1139 1140 i = 0; 1141 while (all_mechanisms[i].mechanism != NULL) 1142 { 1143 if (_dbus_string_equal_c_str (name, 1144 all_mechanisms[i].mechanism)) 1145 1146 return &all_mechanisms[i]; 1147 1148 ++i; 1149 } 1150 1151 return NULL; 1152} 1153 1154static dbus_bool_t 1155send_rejected (DBusAuth *auth) 1156{ 1157 DBusString command; 1158 DBusAuthServer *server_auth; 1159 int i; 1160 1161 if (!_dbus_string_init (&command, _DBUS_INT_MAX)) 1162 return FALSE; 1163 1164 if (!_dbus_string_append (&command, 1165 "REJECTED")) 1166 goto nomem; 1167 1168 i = 0; 1169 while (all_mechanisms[i].mechanism != NULL) 1170 { 1171 if (!_dbus_string_append (&command, 1172 " ")) 1173 goto nomem; 1174 1175 if (!_dbus_string_append (&command, 1176 all_mechanisms[i].mechanism)) 1177 goto nomem; 1178 1179 ++i; 1180 } 1181 1182 if (!_dbus_string_append (&command, "\r\n")) 1183 goto nomem; 1184 1185 if (!_dbus_string_copy (&command, 0, &auth->outgoing, 1186 _dbus_string_get_length (&auth->outgoing))) 1187 goto nomem; 1188 1189 shutdown_mech (auth); 1190 1191 _dbus_assert (DBUS_AUTH_IS_SERVER (auth)); 1192 server_auth = DBUS_AUTH_SERVER (auth); 1193 server_auth->failures += 1; 1194 1195 _dbus_string_free (&command); 1196 1197 return TRUE; 1198 1199 nomem: 1200 _dbus_string_free (&command); 1201 return FALSE; 1202} 1203 1204static dbus_bool_t 1205process_auth (DBusAuth *auth, 1206 const DBusString *command, 1207 const DBusString *args) 1208{ 1209 if (auth->mech) 1210 { 1211 /* We are already using a mechanism, client is on crack */ 1212 if (!_dbus_string_append (&auth->outgoing, 1213 "ERROR \"Sent AUTH while another AUTH in progress\"\r\n")) 1214 return FALSE; 1215 1216 return TRUE; 1217 } 1218 else if (_dbus_string_get_length (args) == 0) 1219 { 1220 /* No args to the auth, send mechanisms */ 1221 if (!send_rejected (auth)) 1222 return FALSE; 1223 1224 return TRUE; 1225 } 1226 else 1227 { 1228 int i; 1229 DBusString mech; 1230 DBusString base64_response; 1231 DBusString decoded_response; 1232 1233 _dbus_string_find_blank (args, 0, &i); 1234 1235 if (!_dbus_string_init (&mech, _DBUS_INT_MAX)) 1236 return FALSE; 1237 1238 if (!_dbus_string_init (&base64_response, _DBUS_INT_MAX)) 1239 { 1240 _dbus_string_free (&mech); 1241 return FALSE; 1242 } 1243 1244 if (!_dbus_string_init (&decoded_response, _DBUS_INT_MAX)) 1245 { 1246 _dbus_string_free (&mech); 1247 _dbus_string_free (&base64_response); 1248 return FALSE; 1249 } 1250 1251 if (!_dbus_string_copy_len (args, 0, i, &mech, 0)) 1252 goto failed; 1253 1254 if (!_dbus_string_copy (args, i, &base64_response, 0)) 1255 goto failed; 1256 1257 if (!_dbus_string_base64_decode (&base64_response, 0, 1258 &decoded_response, 0)) 1259 goto failed; 1260 1261 auth->mech = find_mech (&mech); 1262 if (auth->mech != NULL) 1263 { 1264 _dbus_verbose ("Trying mechanism %s with initial response of %d bytes\n", 1265 auth->mech->mechanism, 1266 _dbus_string_get_length (&decoded_response)); 1267 1268 if (!(* auth->mech->server_data_func) (auth, 1269 &decoded_response)) 1270 goto failed; 1271 } 1272 else 1273 { 1274 /* Unsupported mechanism */ 1275 if (!send_rejected (auth)) 1276 return FALSE; 1277 } 1278 1279 _dbus_string_free (&mech); 1280 _dbus_string_free (&base64_response); 1281 _dbus_string_free (&decoded_response); 1282 1283 return TRUE; 1284 1285 failed: 1286 auth->mech = NULL; 1287 _dbus_string_free (&mech); 1288 _dbus_string_free (&base64_response); 1289 _dbus_string_free (&decoded_response); 1290 return FALSE; 1291 } 1292} 1293 1294static dbus_bool_t 1295process_cancel (DBusAuth *auth, 1296 const DBusString *command, 1297 const DBusString *args) 1298{ 1299 shutdown_mech (auth); 1300 1301 return TRUE; 1302} 1303 1304static dbus_bool_t 1305process_begin (DBusAuth *auth, 1306 const DBusString *command, 1307 const DBusString *args) 1308{ 1309 if (auth->authenticated_pending_begin) 1310 auth->authenticated = TRUE; 1311 else 1312 { 1313 auth->need_disconnect = TRUE; /* client trying to send data before auth, 1314 * kick it 1315 */ 1316 shutdown_mech (auth); 1317 } 1318 1319 return TRUE; 1320} 1321 1322static dbus_bool_t 1323process_data_server (DBusAuth *auth, 1324 const DBusString *command, 1325 const DBusString *args) 1326{ 1327 if (auth->mech != NULL) 1328 { 1329 DBusString decoded; 1330 1331 if (!_dbus_string_init (&decoded, _DBUS_INT_MAX)) 1332 return FALSE; 1333 1334 if (!_dbus_string_base64_decode (args, 0, &decoded, 0)) 1335 { 1336 _dbus_string_free (&decoded); 1337 return FALSE; 1338 } 1339 1340#ifdef DBUS_ENABLE_VERBOSE_MODE 1341 if (_dbus_string_validate_ascii (&decoded, 0, 1342 _dbus_string_get_length (&decoded))) 1343 { 1344 const char *s; 1345 _dbus_string_get_const_data (&decoded, &s); 1346 _dbus_verbose ("data: '%s'\n", s); 1347 } 1348#endif 1349 1350 if (!(* auth->mech->server_data_func) (auth, &decoded)) 1351 { 1352 _dbus_string_free (&decoded); 1353 return FALSE; 1354 } 1355 1356 _dbus_string_free (&decoded); 1357 } 1358 else 1359 { 1360 if (!_dbus_string_append (&auth->outgoing, 1361 "ERROR \"Not currently in an auth conversation\"\r\n")) 1362 return FALSE; 1363 } 1364 1365 return TRUE; 1366} 1367 1368static dbus_bool_t 1369process_error_server (DBusAuth *auth, 1370 const DBusString *command, 1371 const DBusString *args) 1372{ 1373 1374 return TRUE; 1375} 1376 1377/* return FALSE if no memory, TRUE if all OK */ 1378static dbus_bool_t 1379get_word (const DBusString *str, 1380 int *start, 1381 DBusString *word) 1382{ 1383 int i; 1384 1385 _dbus_string_skip_blank (str, *start, start); 1386 _dbus_string_find_blank (str, *start, &i); 1387 1388 if (i > *start) 1389 { 1390 if (!_dbus_string_copy_len (str, *start, i - *start, word, 0)) 1391 return FALSE; 1392 1393 *start = i; 1394 } 1395 1396 return TRUE; 1397} 1398 1399static dbus_bool_t 1400record_mechanisms (DBusAuth *auth, 1401 const DBusString *command, 1402 const DBusString *args) 1403{ 1404 int next; 1405 int len; 1406 1407 if (auth->already_got_mechanisms) 1408 return TRUE; 1409 1410 len = _dbus_string_get_length (args); 1411 1412 next = 0; 1413 while (next < len) 1414 { 1415 DBusString m; 1416 const DBusAuthMechanismHandler *mech; 1417 1418 if (!_dbus_string_init (&m, _DBUS_INT_MAX)) 1419 goto nomem; 1420 1421 if (!get_word (args, &next, &m)) 1422 goto nomem; 1423 1424 mech = find_mech (&m); 1425 1426 if (mech != NULL) 1427 { 1428 /* FIXME right now we try mechanisms in the order 1429 * the server lists them; should we do them in 1430 * some more deterministic order? 1431 * 1432 * Probably in all_mechanisms order, our order of 1433 * preference. Of course when the server is us, 1434 * it lists things in that order anyhow. 1435 */ 1436 1437 _dbus_verbose ("Adding mechanism %s to list we will try\n", 1438 mech->mechanism); 1439 1440 if (!_dbus_list_append (& DBUS_AUTH_CLIENT (auth)->mechs_to_try, 1441 (void*) mech)) 1442 goto nomem; 1443 } 1444 else 1445 { 1446 const char *s; 1447 1448 _dbus_string_get_const_data (&m, &s); 1449 _dbus_verbose ("Server offered mechanism \"%s\" that we don't know how to use\n", 1450 s); 1451 } 1452 1453 _dbus_string_free (&m); 1454 } 1455 1456 auth->already_got_mechanisms = TRUE; 1457 1458 return TRUE; 1459 1460 nomem: 1461 _dbus_list_clear (& DBUS_AUTH_CLIENT (auth)->mechs_to_try); 1462 1463 return FALSE; 1464} 1465 1466static dbus_bool_t 1467client_try_next_mechanism (DBusAuth *auth) 1468{ 1469 const DBusAuthMechanismHandler *mech; 1470 DBusString auth_command; 1471 1472 if (DBUS_AUTH_CLIENT (auth)->mechs_to_try == NULL) 1473 return FALSE; 1474 1475 mech = DBUS_AUTH_CLIENT (auth)->mechs_to_try->data; 1476 1477 if (!_dbus_string_init (&auth_command, _DBUS_INT_MAX)) 1478 return FALSE; 1479 1480 if (!_dbus_string_append (&auth_command, 1481 "AUTH ")) 1482 { 1483 _dbus_string_free (&auth_command); 1484 return FALSE; 1485 } 1486 1487 if (!_dbus_string_append (&auth_command, 1488 mech->mechanism)) 1489 { 1490 _dbus_string_free (&auth_command); 1491 return FALSE; 1492 } 1493 1494 if (mech->client_initial_response_func != NULL) 1495 { 1496 if (!_dbus_string_append (&auth_command, " ")) 1497 { 1498 _dbus_string_free (&auth_command); 1499 return FALSE; 1500 } 1501 1502 if (!(* mech->client_initial_response_func) (auth, &auth_command)) 1503 { 1504 _dbus_string_free (&auth_command); 1505 return FALSE; 1506 } 1507 } 1508 1509 if (!_dbus_string_append (&auth_command, 1510 "\r\n")) 1511 { 1512 _dbus_string_free (&auth_command); 1513 return FALSE; 1514 } 1515 1516 if (!_dbus_string_copy (&auth_command, 0, 1517 &auth->outgoing, 1518 _dbus_string_get_length (&auth->outgoing))) 1519 { 1520 _dbus_string_free (&auth_command); 1521 return FALSE; 1522 } 1523 1524 auth->mech = mech; 1525 _dbus_list_pop_first (& DBUS_AUTH_CLIENT (auth)->mechs_to_try); 1526 1527 _dbus_verbose ("Trying mechanism %s\n", 1528 auth->mech->mechanism); 1529 1530 _dbus_string_free (&auth_command); 1531 1532 return TRUE; 1533} 1534 1535static dbus_bool_t 1536process_rejected (DBusAuth *auth, 1537 const DBusString *command, 1538 const DBusString *args) 1539{ 1540 shutdown_mech (auth); 1541 1542 if (!auth->already_got_mechanisms) 1543 { 1544 if (!record_mechanisms (auth, command, args)) 1545 return FALSE; 1546 } 1547 1548 if (DBUS_AUTH_CLIENT (auth)->mechs_to_try != NULL) 1549 { 1550 client_try_next_mechanism (auth); 1551 } 1552 else 1553 { 1554 /* Give up */ 1555 auth->need_disconnect = TRUE; 1556 } 1557 1558 return TRUE; 1559} 1560 1561static dbus_bool_t 1562process_ok (DBusAuth *auth, 1563 const DBusString *command, 1564 const DBusString *args) 1565{ 1566 if (!_dbus_string_append (&auth->outgoing, 1567 "BEGIN\r\n")) 1568 return FALSE; 1569 1570 auth->authenticated_pending_output = TRUE; 1571 1572 return TRUE; 1573} 1574 1575static dbus_bool_t 1576process_data_client (DBusAuth *auth, 1577 const DBusString *command, 1578 const DBusString *args) 1579{ 1580 if (auth->mech != NULL) 1581 { 1582 DBusString decoded; 1583 1584 if (!_dbus_string_init (&decoded, _DBUS_INT_MAX)) 1585 return FALSE; 1586 1587 if (!_dbus_string_base64_decode (args, 0, &decoded, 0)) 1588 { 1589 _dbus_string_free (&decoded); 1590 return FALSE; 1591 } 1592 1593#ifdef DBUS_ENABLE_VERBOSE_MODE 1594 if (_dbus_string_validate_ascii (&decoded, 0, 1595 _dbus_string_get_length (&decoded))) 1596 { 1597 const char *s; 1598 _dbus_string_get_const_data (&decoded, &s); 1599 _dbus_verbose ("data: '%s'\n", s); 1600 } 1601#endif 1602 1603 if (!(* auth->mech->client_data_func) (auth, &decoded)) 1604 { 1605 _dbus_string_free (&decoded); 1606 return FALSE; 1607 } 1608 1609 _dbus_string_free (&decoded); 1610 } 1611 else 1612 { 1613 if (!_dbus_string_append (&auth->outgoing, 1614 "ERROR \"Got DATA when not in an auth exchange\"\r\n")) 1615 return FALSE; 1616 } 1617 1618 return TRUE; 1619} 1620 1621static dbus_bool_t 1622process_error_client (DBusAuth *auth, 1623 const DBusString *command, 1624 const DBusString *args) 1625{ 1626 return TRUE; 1627} 1628 1629static dbus_bool_t 1630process_unknown (DBusAuth *auth, 1631 const DBusString *command, 1632 const DBusString *args) 1633{ 1634 if (!_dbus_string_append (&auth->outgoing, 1635 "ERROR \"Unknown command\"\r\n")) 1636 return FALSE; 1637 1638 return TRUE; 1639} 1640 1641/* returns whether to call it again right away */ 1642static dbus_bool_t 1643process_command (DBusAuth *auth) 1644{ 1645 DBusString command; 1646 DBusString args; 1647 int eol; 1648 int i, j; 1649 dbus_bool_t retval; 1650 1651 /* _dbus_verbose (" trying process_command()\n"); */ 1652 1653 retval = FALSE; 1654 1655 eol = 0; 1656 if (!_dbus_string_find (&auth->incoming, 0, "\r\n", &eol)) 1657 return FALSE; 1658 1659 if (!_dbus_string_init (&command, _DBUS_INT_MAX)) 1660 { 1661 auth->needed_memory = TRUE; 1662 return FALSE; 1663 } 1664 1665 if (!_dbus_string_init (&args, _DBUS_INT_MAX)) 1666 { 1667 auth->needed_memory = TRUE; 1668 return FALSE; 1669 } 1670 1671 if (eol > _DBUS_ONE_MEGABYTE) 1672 { 1673 /* This is a giant line, someone is trying to hose us. */ 1674 if (!_dbus_string_append (&auth->outgoing, "ERROR \"Command too long\"\r\n")) 1675 goto out; 1676 else 1677 goto next_command; 1678 } 1679 1680 if (!_dbus_string_copy_len (&auth->incoming, 0, eol, &command, 0)) 1681 goto out; 1682 1683 if (!_dbus_string_validate_ascii (&command, 0, 1684 _dbus_string_get_length (&command))) 1685 { 1686 _dbus_verbose ("Command contained non-ASCII chars or embedded nul\n"); 1687 if (!_dbus_string_append (&auth->outgoing, "ERROR \"Command contained non-ASCII\"\r\n")) 1688 goto out; 1689 else 1690 goto next_command; 1691 } 1692 1693 { 1694 const char *q; 1695 _dbus_string_get_const_data (&command, &q); 1696 _dbus_verbose ("got command \"%s\"\n", q); 1697 } 1698 1699 _dbus_string_find_blank (&command, 0, &i); 1700 _dbus_string_skip_blank (&command, i, &j); 1701 1702 if (j > i) 1703 _dbus_string_delete (&command, i, j - i); 1704 1705 if (!_dbus_string_move (&command, i, &args, 0)) 1706 goto out; 1707 1708 i = 0; 1709 while (auth->handlers[i].command != NULL) 1710 { 1711 if (_dbus_string_equal_c_str (&command, 1712 auth->handlers[i].command)) 1713 { 1714 _dbus_verbose ("Processing auth command %s\n", 1715 auth->handlers[i].command); 1716 1717 if (!(* auth->handlers[i].func) (auth, &command, &args)) 1718 goto out; 1719 1720 break; 1721 } 1722 ++i; 1723 } 1724 1725 if (auth->handlers[i].command == NULL) 1726 { 1727 if (!process_unknown (auth, &command, &args)) 1728 goto out; 1729 } 1730 1731 next_command: 1732 1733 /* We've succeeded in processing the whole command so drop it out 1734 * of the incoming buffer and return TRUE to try another command. 1735 */ 1736 1737 _dbus_string_delete (&auth->incoming, 0, eol); 1738 1739 /* kill the \r\n */ 1740 _dbus_string_delete (&auth->incoming, 0, 2); 1741 1742 retval = TRUE; 1743 1744 out: 1745 _dbus_string_free (&args); 1746 _dbus_string_free (&command); 1747 1748 if (!retval) 1749 auth->needed_memory = TRUE; 1750 else 1751 auth->needed_memory = FALSE; 1752 1753 return retval; 1754} 1755 1756 1757/** @} */ 1758 1759/** 1760 * @addtogroup DBusAuth 1761 * @{ 1762 */ 1763 1764/** 1765 * Creates a new auth conversation object for the server side. 1766 * See doc/dbus-sasl-profile.txt for full details on what 1767 * this object does. 1768 * 1769 * @returns the new object or #NULL if no memory 1770 */ 1771DBusAuth* 1772_dbus_auth_server_new (void) 1773{ 1774 DBusAuth *auth; 1775 DBusAuthServer *server_auth; 1776 1777 auth = _dbus_auth_new (sizeof (DBusAuthServer)); 1778 if (auth == NULL) 1779 return NULL; 1780 1781 auth->handlers = server_handlers; 1782 1783 server_auth = DBUS_AUTH_SERVER (auth); 1784 1785 /* perhaps this should be per-mechanism with a lower 1786 * max 1787 */ 1788 server_auth->failures = 0; 1789 server_auth->max_failures = 6; 1790 1791 return auth; 1792} 1793 1794/** 1795 * Creates a new auth conversation object for the client side. 1796 * See doc/dbus-sasl-profile.txt for full details on what 1797 * this object does. 1798 * 1799 * @returns the new object or #NULL if no memory 1800 */ 1801DBusAuth* 1802_dbus_auth_client_new (void) 1803{ 1804 DBusAuth *auth; 1805 1806 auth = _dbus_auth_new (sizeof (DBusAuthClient)); 1807 if (auth == NULL) 1808 return NULL; 1809 1810 auth->handlers = client_handlers; 1811 1812 /* Add a default mechanism to try */ 1813 if (!_dbus_list_append (& DBUS_AUTH_CLIENT (auth)->mechs_to_try, 1814 (void*) &all_mechanisms[0])) 1815 { 1816 _dbus_auth_unref (auth); 1817 return NULL; 1818 } 1819 1820 /* Now try the mechanism we just added */ 1821 if (!client_try_next_mechanism (auth)) 1822 { 1823 _dbus_auth_unref (auth); 1824 return NULL; 1825 } 1826 1827 return auth; 1828} 1829 1830/** 1831 * Increments the refcount of an auth object. 1832 * 1833 * @param auth the auth conversation 1834 */ 1835void 1836_dbus_auth_ref (DBusAuth *auth) 1837{ 1838 _dbus_assert (auth != NULL); 1839 1840 auth->refcount += 1; 1841} 1842 1843/** 1844 * Decrements the refcount of an auth object. 1845 * 1846 * @param auth the auth conversation 1847 */ 1848void 1849_dbus_auth_unref (DBusAuth *auth) 1850{ 1851 _dbus_assert (auth != NULL); 1852 _dbus_assert (auth->refcount > 0); 1853 1854 auth->refcount -= 1; 1855 if (auth->refcount == 0) 1856 { 1857 shutdown_mech (auth); 1858 1859 if (DBUS_AUTH_IS_CLIENT (auth)) 1860 { 1861 _dbus_list_clear (& DBUS_AUTH_CLIENT (auth)->mechs_to_try); 1862 } 1863 1864 if (auth->keyring) 1865 _dbus_keyring_unref (auth->keyring); 1866 1867 _dbus_string_free (&auth->identity); 1868 _dbus_string_free (&auth->incoming); 1869 _dbus_string_free (&auth->outgoing); 1870 dbus_free (auth); 1871 } 1872} 1873 1874/** 1875 * @param auth the auth conversation object 1876 * @returns #TRUE if we're in a final state 1877 */ 1878#define DBUS_AUTH_IN_END_STATE(auth) ((auth)->need_disconnect || (auth)->authenticated) 1879 1880/** 1881 * Analyzes buffered input and moves the auth conversation forward, 1882 * returning the new state of the auth conversation. 1883 * 1884 * @param auth the auth conversation 1885 * @returns the new state 1886 */ 1887DBusAuthState 1888_dbus_auth_do_work (DBusAuth *auth) 1889{ 1890 auth->needed_memory = FALSE; 1891 1892 /* Max amount we'll buffer up before deciding someone's on crack */ 1893#define MAX_BUFFER (16 * _DBUS_ONE_KILOBYTE) 1894 1895 do 1896 { 1897 if (DBUS_AUTH_IN_END_STATE (auth)) 1898 break; 1899 1900 if (_dbus_string_get_length (&auth->incoming) > MAX_BUFFER || 1901 _dbus_string_get_length (&auth->outgoing) > MAX_BUFFER) 1902 { 1903 auth->need_disconnect = TRUE; 1904 _dbus_verbose ("Disconnecting due to excessive data buffered in auth phase\n"); 1905 break; 1906 } 1907 1908 if (auth->mech == NULL && 1909 auth->already_got_mechanisms && 1910 DBUS_AUTH_CLIENT (auth)->mechs_to_try == NULL) 1911 { 1912 auth->need_disconnect = TRUE; 1913 _dbus_verbose ("Disconnecting because we are out of mechanisms to try using\n"); 1914 break; 1915 } 1916 } 1917 while (process_command (auth)); 1918 1919 if (DBUS_AUTH_IS_SERVER (auth) && 1920 DBUS_AUTH_SERVER (auth)->failures >= 1921 DBUS_AUTH_SERVER (auth)->max_failures) 1922 auth->need_disconnect = TRUE; 1923 1924 if (auth->need_disconnect) 1925 return DBUS_AUTH_STATE_NEED_DISCONNECT; 1926 else if (auth->authenticated) 1927 { 1928 if (_dbus_string_get_length (&auth->incoming) > 0) 1929 return DBUS_AUTH_STATE_AUTHENTICATED_WITH_UNUSED_BYTES; 1930 else 1931 return DBUS_AUTH_STATE_AUTHENTICATED; 1932 } 1933 else if (auth->needed_memory) 1934 return DBUS_AUTH_STATE_WAITING_FOR_MEMORY; 1935 else if (_dbus_string_get_length (&auth->outgoing) > 0) 1936 return DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND; 1937 else 1938 return DBUS_AUTH_STATE_WAITING_FOR_INPUT; 1939} 1940 1941/** 1942 * Gets bytes that need to be sent to the peer we're conversing with. 1943 * After writing some bytes, _dbus_auth_bytes_sent() must be called 1944 * to notify the auth object that they were written. 1945 * 1946 * @param auth the auth conversation 1947 * @param str return location for a ref to the buffer to send 1948 * @returns #FALSE if nothing to send 1949 */ 1950dbus_bool_t 1951_dbus_auth_get_bytes_to_send (DBusAuth *auth, 1952 const DBusString **str) 1953{ 1954 _dbus_assert (auth != NULL); 1955 _dbus_assert (str != NULL); 1956 1957 *str = NULL; 1958 1959 if (DBUS_AUTH_IN_END_STATE (auth)) 1960 return FALSE; 1961 1962 if (_dbus_string_get_length (&auth->outgoing) == 0) 1963 return FALSE; 1964 1965 *str = &auth->outgoing; 1966 1967 return TRUE; 1968} 1969 1970/** 1971 * Notifies the auth conversation object that 1972 * the given number of bytes of the outgoing buffer 1973 * have been written out. 1974 * 1975 * @param auth the auth conversation 1976 * @param bytes_sent number of bytes written out 1977 */ 1978void 1979_dbus_auth_bytes_sent (DBusAuth *auth, 1980 int bytes_sent) 1981{ 1982 { 1983 const char *s; 1984 _dbus_string_get_const_data (&auth->outgoing, &s); 1985 _dbus_verbose ("Sent %d bytes of: %s\n", bytes_sent, s); 1986 } 1987 1988 _dbus_string_delete (&auth->outgoing, 1989 0, bytes_sent); 1990 1991 if (auth->authenticated_pending_output && 1992 _dbus_string_get_length (&auth->outgoing) == 0) 1993 auth->authenticated = TRUE; 1994} 1995 1996/** 1997 * Stores bytes received from the peer we're conversing with. 1998 * 1999 * @param auth the auth conversation 2000 * @param str the received bytes. 2001 * @returns #FALSE if not enough memory to store the bytes or we were already authenticated. 2002 */ 2003dbus_bool_t 2004_dbus_auth_bytes_received (DBusAuth *auth, 2005 const DBusString *str) 2006{ 2007 _dbus_assert (auth != NULL); 2008 _dbus_assert (str != NULL); 2009 2010 if (DBUS_AUTH_IN_END_STATE (auth)) 2011 return FALSE; 2012 2013 auth->needed_memory = FALSE; 2014 2015 if (!_dbus_string_copy (str, 0, 2016 &auth->incoming, 2017 _dbus_string_get_length (&auth->incoming))) 2018 { 2019 auth->needed_memory = TRUE; 2020 return FALSE; 2021 } 2022 2023 _dbus_auth_do_work (auth); 2024 2025 return TRUE; 2026} 2027 2028/** 2029 * Returns leftover bytes that were not used as part of the auth 2030 * conversation. These bytes will be part of the message stream 2031 * instead. This function may not be called until authentication has 2032 * succeeded. 2033 * 2034 * @param auth the auth conversation 2035 * @param str string to append the unused bytes to 2036 * @returns #FALSE if not enough memory to return the bytes 2037 */ 2038dbus_bool_t 2039_dbus_auth_get_unused_bytes (DBusAuth *auth, 2040 DBusString *str) 2041{ 2042 if (!DBUS_AUTH_IN_END_STATE (auth)) 2043 return FALSE; 2044 2045 if (!_dbus_string_move (&auth->incoming, 2046 0, str, 2047 _dbus_string_get_length (str))) 2048 return FALSE; 2049 2050 return TRUE; 2051} 2052 2053/** 2054 * Called post-authentication, indicates whether we need to encode 2055 * the message stream with _dbus_auth_encode_data() prior to 2056 * sending it to the peer. 2057 * 2058 * @param auth the auth conversation 2059 * @returns #TRUE if we need to encode the stream 2060 */ 2061dbus_bool_t 2062_dbus_auth_needs_encoding (DBusAuth *auth) 2063{ 2064 if (!auth->authenticated) 2065 return FALSE; 2066 2067 if (auth->mech != NULL) 2068 { 2069 if (DBUS_AUTH_IS_CLIENT (auth)) 2070 return auth->mech->client_encode_func != NULL; 2071 else 2072 return auth->mech->server_encode_func != NULL; 2073 } 2074 else 2075 return FALSE; 2076} 2077 2078/** 2079 * Called post-authentication, encodes a block of bytes for sending to 2080 * the peer. If no encoding was negotiated, just copies the bytes 2081 * (you can avoid this by checking _dbus_auth_needs_encoding()). 2082 * 2083 * @param auth the auth conversation 2084 * @param plaintext the plain text data 2085 * @param encoded initialized string to where encoded data is appended 2086 * @returns #TRUE if we had enough memory and successfully encoded 2087 */ 2088dbus_bool_t 2089_dbus_auth_encode_data (DBusAuth *auth, 2090 const DBusString *plaintext, 2091 DBusString *encoded) 2092{ 2093 _dbus_assert (plaintext != encoded); 2094 2095 if (!auth->authenticated) 2096 return FALSE; 2097 2098 if (_dbus_auth_needs_encoding (auth)) 2099 { 2100 if (DBUS_AUTH_IS_CLIENT (auth)) 2101 return (* auth->mech->client_encode_func) (auth, plaintext, encoded); 2102 else 2103 return (* auth->mech->server_encode_func) (auth, plaintext, encoded); 2104 } 2105 else 2106 { 2107 return _dbus_string_copy (plaintext, 0, encoded, 2108 _dbus_string_get_length (encoded)); 2109 } 2110} 2111 2112/** 2113 * Called post-authentication, indicates whether we need to decode 2114 * the message stream with _dbus_auth_decode_data() after 2115 * receiving it from the peer. 2116 * 2117 * @param auth the auth conversation 2118 * @returns #TRUE if we need to encode the stream 2119 */ 2120dbus_bool_t 2121_dbus_auth_needs_decoding (DBusAuth *auth) 2122{ 2123 if (!auth->authenticated) 2124 return FALSE; 2125 2126 if (auth->mech != NULL) 2127 { 2128 if (DBUS_AUTH_IS_CLIENT (auth)) 2129 return auth->mech->client_decode_func != NULL; 2130 else 2131 return auth->mech->server_decode_func != NULL; 2132 } 2133 else 2134 return FALSE; 2135} 2136 2137 2138/** 2139 * Called post-authentication, decodes a block of bytes received from 2140 * the peer. If no encoding was negotiated, just copies the bytes (you 2141 * can avoid this by checking _dbus_auth_needs_decoding()). 2142 * 2143 * @todo We need to be able to distinguish "out of memory" error 2144 * from "the data is hosed" error. 2145 * 2146 * @param auth the auth conversation 2147 * @param encoded the encoded data 2148 * @param plaintext initialized string where decoded data is appended 2149 * @returns #TRUE if we had enough memory and successfully decoded 2150 */ 2151dbus_bool_t 2152_dbus_auth_decode_data (DBusAuth *auth, 2153 const DBusString *encoded, 2154 DBusString *plaintext) 2155{ 2156 _dbus_assert (plaintext != encoded); 2157 2158 if (!auth->authenticated) 2159 return FALSE; 2160 2161 if (_dbus_auth_needs_decoding (auth)) 2162 { 2163 if (DBUS_AUTH_IS_CLIENT (auth)) 2164 return (* auth->mech->client_decode_func) (auth, encoded, plaintext); 2165 else 2166 return (* auth->mech->server_decode_func) (auth, encoded, plaintext); 2167 } 2168 else 2169 { 2170 return _dbus_string_copy (encoded, 0, plaintext, 2171 _dbus_string_get_length (plaintext)); 2172 } 2173} 2174 2175/** 2176 * Sets credentials received via reliable means from the operating 2177 * system. 2178 * 2179 * @param auth the auth conversation 2180 * @param credentials the credentials received 2181 */ 2182void 2183_dbus_auth_set_credentials (DBusAuth *auth, 2184 const DBusCredentials *credentials) 2185{ 2186 auth->credentials = *credentials; 2187} 2188 2189/** 2190 * Gets the identity we authorized the client as. Apps may have 2191 * different policies as to what identities they allow. 2192 * 2193 * @param auth the auth conversation 2194 * @param credentials the credentials we've authorized 2195 */ 2196void 2197_dbus_auth_get_identity (DBusAuth *auth, 2198 DBusCredentials *credentials) 2199{ 2200 if (auth->authenticated) 2201 { 2202 *credentials = auth->authorized_identity; 2203 } 2204 else 2205 { 2206 credentials->pid = -1; 2207 credentials->uid = -1; 2208 credentials->gid = -1; 2209 } 2210} 2211 2212/** 2213 * Sets the "authentication context" which scopes cookies 2214 * with the DBUS_COOKIE_SHA1 auth mechanism for example. 2215 * 2216 * @param auth the auth conversation 2217 * @param context the context 2218 * @returns #FALSE if no memory 2219 */ 2220dbus_bool_t 2221_dbus_auth_set_context (DBusAuth *auth, 2222 const DBusString *context) 2223{ 2224 return _dbus_string_replace_len (context, 0, _dbus_string_get_length (context), 2225 &auth->context, 0, _dbus_string_get_length (context)); 2226} 2227 2228/** @} */ 2229 2230#ifdef DBUS_BUILD_TESTS 2231#include "dbus-test.h" 2232#include "dbus-auth-script.h" 2233#include <stdio.h> 2234 2235static dbus_bool_t 2236process_test_subdir (const DBusString *test_base_dir, 2237 const char *subdir) 2238{ 2239 DBusString test_directory; 2240 DBusString filename; 2241 DBusDirIter *dir; 2242 dbus_bool_t retval; 2243 DBusError error; 2244 2245 retval = FALSE; 2246 dir = NULL; 2247 2248 if (!_dbus_string_init (&test_directory, _DBUS_INT_MAX)) 2249 _dbus_assert_not_reached ("didn't allocate test_directory\n"); 2250 2251 _dbus_string_init_const (&filename, subdir); 2252 2253 if (!_dbus_string_copy (test_base_dir, 0, 2254 &test_directory, 0)) 2255 _dbus_assert_not_reached ("couldn't copy test_base_dir to test_directory"); 2256 2257 if (!_dbus_concat_dir_and_file (&test_directory, &filename)) 2258 _dbus_assert_not_reached ("couldn't allocate full path"); 2259 2260 _dbus_string_free (&filename); 2261 if (!_dbus_string_init (&filename, _DBUS_INT_MAX)) 2262 _dbus_assert_not_reached ("didn't allocate filename string\n"); 2263 2264 dbus_error_init (&error); 2265 dir = _dbus_directory_open (&test_directory, &error); 2266 if (dir == NULL) 2267 { 2268 const char *s; 2269 _dbus_string_get_const_data (&test_directory, &s); 2270 _dbus_warn ("Could not open %s: %s\n", s, 2271 error.message); 2272 dbus_error_free (&error); 2273 goto failed; 2274 } 2275 2276 printf ("Testing:\n"); 2277 2278 next: 2279 while (_dbus_directory_get_next_file (dir, &filename, &error)) 2280 { 2281 DBusString full_path; 2282 2283 if (!_dbus_string_init (&full_path, _DBUS_INT_MAX)) 2284 _dbus_assert_not_reached ("couldn't init string"); 2285 2286 if (!_dbus_string_copy (&test_directory, 0, &full_path, 0)) 2287 _dbus_assert_not_reached ("couldn't copy dir to full_path"); 2288 2289 if (!_dbus_concat_dir_and_file (&full_path, &filename)) 2290 _dbus_assert_not_reached ("couldn't concat file to dir"); 2291 2292 if (!_dbus_string_ends_with_c_str (&filename, ".auth-script")) 2293 { 2294 const char *filename_c; 2295 _dbus_string_get_const_data (&filename, &filename_c); 2296 _dbus_verbose ("Skipping non-.auth-script file %s\n", 2297 filename_c); 2298 _dbus_string_free (&full_path); 2299 goto next; 2300 } 2301 2302 { 2303 const char *s; 2304 _dbus_string_get_const_data (&filename, &s); 2305 printf (" %s\n", s); 2306 } 2307 2308 if (!_dbus_auth_script_run (&full_path)) 2309 { 2310 _dbus_string_free (&full_path); 2311 goto failed; 2312 } 2313 else 2314 _dbus_string_free (&full_path); 2315 } 2316 2317 if (dbus_error_is_set (&error)) 2318 { 2319 const char *s; 2320 _dbus_string_get_const_data (&test_directory, &s); 2321 _dbus_warn ("Could not get next file in %s: %s\n", 2322 s, error.message); 2323 dbus_error_free (&error); 2324 goto failed; 2325 } 2326 2327 retval = TRUE; 2328 2329 failed: 2330 2331 if (dir) 2332 _dbus_directory_close (dir); 2333 _dbus_string_free (&test_directory); 2334 _dbus_string_free (&filename); 2335 2336 return retval; 2337} 2338 2339static dbus_bool_t 2340process_test_dirs (const char *test_data_dir) 2341{ 2342 DBusString test_directory; 2343 dbus_bool_t retval; 2344 2345 retval = FALSE; 2346 2347 _dbus_string_init_const (&test_directory, test_data_dir); 2348 2349 if (!process_test_subdir (&test_directory, "auth")) 2350 goto failed; 2351 2352 retval = TRUE; 2353 2354 failed: 2355 2356 _dbus_string_free (&test_directory); 2357 2358 return retval; 2359} 2360 2361dbus_bool_t 2362_dbus_auth_test (const char *test_data_dir) 2363{ 2364 2365 if (test_data_dir == NULL) 2366 return TRUE; 2367 2368 if (!process_test_dirs (test_data_dir)) 2369 return FALSE; 2370 2371 return TRUE; 2372} 2373 2374#endif /* DBUS_BUILD_TESTS */ 2375