/mandos/release : revision 237.7.501

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

17

* published by the Free Software Foundation, either version 3 of the

18

* License, or (at your option) any later version.

19

*

20

* This program is distributed in the hope that it will be useful, but

12

13

14

*

15

* This file is part of Mandos.

16

*

17

* Mandos is free software: you can redistribute it and/or modify it

18

* under the terms of the GNU General Public License as published by

19

* the Free Software Foundation, either version 3 of the License, or

20

* (at your option) any later version.

21

*

22

* Mandos is distributed in the hope that it will be useful, but

21

23

* WITHOUT ANY WARRANTY; without even the implied warranty of

22

24

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

23

25

* General Public License for more details.

24

26

*

25

27

* You should have received a copy of the GNU General Public License

26

* along with this program. If not, see

27

* <http://www.gnu.org/licenses/>.

28

* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

28

29

*

29

30

* Contact the authors at <mandos@recompile.se>.

30

31

*/

32

33

/* Needed by GPGME, specifically gpgme_data_seek() */

33

34

#ifndef _LARGEFILE_SOURCE

34

35

#define _LARGEFILE_SOURCE

35

#endif

36

#endif /* not _LARGEFILE_SOURCE */

36

37

#ifndef _FILE_OFFSET_BITS

37

38

#define _FILE_OFFSET_BITS 64

38

#endif

39

#endif /* not _FILE_OFFSET_BITS */

39

40

41

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

42

43

#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror(), remove() */

44

stdout, ferror() */

44

45

#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

45

46

#include <stddef.h> /* NULL, size_t, ssize_t */

46

47

#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

47

48

strtof(), abort() */

48

49

#include <stdbool.h> /* bool, false, true */

49

#include <string.h> /* memset(), strcmp(), strlen(),

50

strerror(), asprintf(), strcpy() */

50

#include <string.h> /* strcmp(), strlen(), strerror(),

51

asprintf(), strncpy(), strsignal()

52

*/

51

53

#include <sys/ioctl.h> /* ioctl */

52

54

#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

53

55

sockaddr_in6, PF_INET6,

57

59

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

58

60

inet_pton(), connect(),

59

61

getnameinfo() */

60

#include <fcntl.h> /* open() */

62

#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */

61

63

#include <dirent.h> /* opendir(), struct dirent, readdir()

62

64

*/

63

65

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

64

66

strtoimax() */

65

#include <errno.h> /* perror(), errno,

67

#include <errno.h> /* perror(), errno, EINTR, EINVAL,

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

66

72

program_invocation_short_name */

67

73

#include <time.h> /* nanosleep(), time(), sleep() */

68

74

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

73

79

*/

74

80

#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

75

81

getuid(), getgid(), seteuid(),

76

setgid(), pause(), _exit() */

82

setgid(), pause(), _exit(),

83

unlinkat() */

77

84

#include <arpa/inet.h> /* inet_pton(), htons() */

78

85

#include <iso646.h> /* not, or, and */

79

86

#include <argp.h> /* struct argp_option, error_t, struct

136

143

137

144

bool debug = false;

138

145

static const char mandos_protocol_version[] = "1";

139

const char * argp_program_version = "mandos-client " VERSION;

140

const char * argp_program_bug_address = "<mandos@recompile.se>";

146

const char *argp_program_version = "mandos-client " VERSION;

147

const char *argp_program_bug_address = "<mandos@recompile.se>";

141

148

static const char sys_class_net[] = "/sys/class/net";

142

149

char *connect_to = NULL;

143

150

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

144

152

uid_t uid = 65534;

145

153

gid_t gid = 65534;

146

154

232

240

.af = af };

233

241

if(new_server->ip == NULL){

234

242

perror_plus("strdup");

243

free(new_server);

235

244

return false;

236

245

}

237

246

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

238

247

if(ret == -1){

239

248

perror_plus("clock_gettime");

249

#ifdef __GNUC__

250

#pragma GCC diagnostic push

251

#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

253

free((char *)(new_server->ip));

254

#ifdef __GNUC__

255

#pragma GCC diagnostic pop

256

#endif

257

free(new_server);

240

258

return false;

241

259

}

242

260

/* Special case of first server */

254

272

return true;

255

273

}

256

274

275

/* Set effective uid to 0, return errno */

276

__attribute__((warn_unused_result))

277

int raise_privileges(void){

278

int old_errno = errno;

279

int ret = 0;

280

if(seteuid(0) == -1){

281

ret = errno;

282

}

283

errno = old_errno;

284

return ret;

285

}

286

287

/* Set effective and real user ID to 0. Return errno. */

288

__attribute__((warn_unused_result))

289

int raise_privileges_permanently(void){

290

int old_errno = errno;

291

int ret = raise_privileges();

292

if(ret != 0){

293

errno = old_errno;

294

return ret;

295

}

296

if(setuid(0) == -1){

297

ret = errno;

298

}

299

errno = old_errno;

300

return ret;

301

}

302

303

/* Set effective user ID to unprivileged saved user ID */

304

__attribute__((warn_unused_result))

305

int lower_privileges(void){

306

int old_errno = errno;

307

int ret = 0;

308

if(seteuid(uid) == -1){

309

ret = errno;

310

}

311

errno = old_errno;

312

return ret;

313

}

314

315

/* Lower privileges permanently */

316

__attribute__((warn_unused_result))

317

int lower_privileges_permanently(void){

318

int old_errno = errno;

319

int ret = 0;

320

if(setuid(uid) == -1){

321

ret = errno;

322

}

323

errno = old_errno;

324

return ret;

325

}

326

257

327

/*

258

328

* Initialize GPGME.

259

329

*/

279

349

return false;

280

350

}

281

351

352

/* Workaround for systems without a real-time clock; see also

353

Debian bug #894495: <https://bugs.debian.org/894495> */

354

do {

355

{

356

time_t currtime = time(NULL);

357

if(currtime != (time_t)-1){

358

struct tm tm;

359

if(gmtime_r(&currtime, &tm) == NULL) {

360

perror_plus("gmtime_r");

361

break;

362

}

363

if(tm.tm_year != 70 or tm.tm_mon != 0){

364

break;

365

}

366

if(debug){

367

fprintf_plus(stderr, "System clock is January 1970");

368

}

369

} else {

370

if(debug){

371

fprintf_plus(stderr, "System clock is invalid");

372

}

373

}

374

}

375

struct stat keystat;

376

ret = fstat(fd, &keystat);

377

if(ret != 0){

378

perror_plus("fstat");

379

break;

380

}

381

ret = raise_privileges();

382

if(ret != 0){

383

errno = ret;

384

perror_plus("Failed to raise privileges");

385

break;

386

}

387

if(debug){

388

fprintf_plus(stderr,

389

"Setting system clock to key file mtime");

390

}

391

time_t keytime = keystat.st_mtim.tv_sec;

392

if(stime(&keytime) != 0){

393

perror_plus("stime");

394

}

395

ret = lower_privileges();

396

if(ret != 0){

397

errno = ret;

398

perror_plus("Failed to lower privileges");

399

}

400

} while(false);

401

282

402

rc = gpgme_data_new_from_fd(&pgp_data, fd);

283

403

if(rc != GPG_ERR_NO_ERROR){

284

404

fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

292

412

gpgme_strsource(rc), gpgme_strerror(rc));

293

413

return false;

294

414

}

415

{

416

gpgme_import_result_t import_result

417

= gpgme_op_import_result(mc->ctx);

418

if((import_result->imported < 1

419

or import_result->not_imported > 0)

420

and import_result->unchanged == 0){

421

fprintf_plus(stderr, "bad gpgme_op_import_results:\n");

422

fprintf_plus(stderr,

423

"The total number of considered keys: %d\n",

424

import_result->considered);

425

fprintf_plus(stderr,

426

"The number of keys without user ID: %d\n",

427

import_result->no_user_id);

428

fprintf_plus(stderr,

429

"The total number of imported keys: %d\n",

430

import_result->imported);

431

fprintf_plus(stderr, "The number of imported RSA keys: %d\n",

432

import_result->imported_rsa);

433

fprintf_plus(stderr, "The number of unchanged keys: %d\n",

434

import_result->unchanged);

435

fprintf_plus(stderr, "The number of new user IDs: %d\n",

436

import_result->new_user_ids);

437

fprintf_plus(stderr, "The number of new sub keys: %d\n",

438

import_result->new_sub_keys);

439

fprintf_plus(stderr, "The number of new signatures: %d\n",

440

import_result->new_signatures);

441

fprintf_plus(stderr, "The number of new revocations: %d\n",

442

import_result->new_revocations);

443

fprintf_plus(stderr,

444

"The total number of secret keys read: %d\n",

445

import_result->secret_read);

446

fprintf_plus(stderr,

447

"The number of imported secret keys: %d\n",

448

import_result->secret_imported);

449

fprintf_plus(stderr,

450

"The number of unchanged secret keys: %d\n",

451

import_result->secret_unchanged);

452

fprintf_plus(stderr, "The number of keys not imported: %d\n",

453

import_result->not_imported);

454

for(gpgme_import_status_t import_status

455

= import_result->imports;

456

import_status != NULL;

457

import_status = import_status->next){

458

fprintf_plus(stderr, "Import status for key: %s\n",

459

import_status->fpr);

460

if(import_status->result != GPG_ERR_NO_ERROR){

461

fprintf_plus(stderr, "Import result: %s: %s\n",

462

gpgme_strsource(import_status->result),

463

gpgme_strerror(import_status->result));

464

}

465

fprintf_plus(stderr, "Key status:\n");

466

fprintf_plus(stderr,

467

import_status->status & GPGME_IMPORT_NEW

468

? "The key was new.\n"

469

: "The key was not new.\n");

470

fprintf_plus(stderr,

471

import_status->status & GPGME_IMPORT_UID

472

? "The key contained new user IDs.\n"

473

: "The key did not contain new user IDs.\n");

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_SIG

476

? "The key contained new signatures.\n"

477

: "The key did not contain new signatures.\n");

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_SUBKEY

480

? "The key contained new sub keys.\n"

481

: "The key did not contain new sub keys.\n");

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SECRET

484

? "The key contained a secret key.\n"

485

: "The key did not contain a secret key.\n");

486

}

487

return false;

488

}

489

}

295

490

296

ret = (int)TEMP_FAILURE_RETRY(close(fd));

491

ret = close(fd);

297

492

if(ret == -1){

298

493

perror_plus("close");

299

494

}

338

533

/* Create new GPGME "context" */

339

534

rc = gpgme_new(&(mc->ctx));

340

535

if(rc != GPG_ERR_NO_ERROR){

341

fprintf_plus(stderr, "Mandos plugin mandos-client: "

342

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

343

gpgme_strerror(rc));

536

fprintf_plus(stderr, "bad gpgme_new: %s: %s\n",

537

gpgme_strsource(rc), gpgme_strerror(rc));

344

538

return false;

345

539

}

346

540

382

576

/* Create new empty GPGME data buffer for the plaintext */

383

577

rc = gpgme_data_new(&dh_plain);

384

578

if(rc != GPG_ERR_NO_ERROR){

385

fprintf_plus(stderr, "Mandos plugin mandos-client: "

386

"bad gpgme_data_new: %s: %s\n",

579

fprintf_plus(stderr, "bad gpgme_data_new: %s: %s\n",

387

580

gpgme_strsource(rc), gpgme_strerror(rc));

388

581

gpgme_data_release(dh_crypto);

389

582

return -1;

402

595

if(result == NULL){

403

596

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

404

597

} else {

405

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

406

result->unsupported_algorithm);

407

fprintf_plus(stderr, "Wrong key usage: %u\n",

408

result->wrong_key_usage);

598

if(result->unsupported_algorithm != NULL) {

599

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

600

result->unsupported_algorithm);

601

}

602

fprintf_plus(stderr, "Wrong key usage: %s\n",

603

result->wrong_key_usage ? "Yes" : "No");

409

604

if(result->file_name != NULL){

410

605

fprintf_plus(stderr, "File name: %s\n", result->file_name);

411

606

}

412

gpgme_recipient_t recipient;

413

recipient = result->recipients;

414

while(recipient != NULL){

607

608

for(gpgme_recipient_t r = result->recipients; r != NULL;

609

r = r->next){

415

610

fprintf_plus(stderr, "Public key algorithm: %s\n",

416

gpgme_pubkey_algo_name

417

(recipient->pubkey_algo));

418

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

611

gpgme_pubkey_algo_name(r->pubkey_algo));

612

fprintf_plus(stderr, "Key ID: %s\n", r->keyid);

419

613

fprintf_plus(stderr, "Secret key available: %s\n",

420

recipient->status == GPG_ERR_NO_SECKEY

421

? "No" : "Yes");

422

recipient = recipient->next;

614

r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");

423

615

}

424

616

}

425

617

}

481

673

return plaintext_length;

482

674

}

483

675

676

__attribute__((warn_unused_result, const))

677

static const char *safe_string(const char *str){

678

if(str == NULL)

679

return "(unknown)";

680

return str;

681

}

682

484

683

__attribute__((warn_unused_result))

485

684

static const char *safer_gnutls_strerror(int value){

486

685

const char *ret = gnutls_strerror(value);

487

if(ret == NULL)

488

ret = "(unknown)";

489

return ret;

686

return safe_string(ret);

490

687

}

491

688

492

689

/* GnuTLS log function callback */

496

693

fprintf_plus(stderr, "GnuTLS: %s", string);

497

694

}

498

695

499

__attribute__((nonnull, warn_unused_result))

696

__attribute__((nonnull(1, 2, 4), warn_unused_result))

500

697

static int init_gnutls_global(const char *pubkeyfilename,

501

698

const char *seckeyfilename,

699

const char *dhparamsfilename,

502

700

mandos_context *mc){

503

701

int ret;

702

unsigned int uret;

504

703

505

704

if(debug){

506

705

fprintf_plus(stderr, "Initializing GnuTLS\n");

507

706

}

508

707

509

ret = gnutls_global_init();

510

if(ret != GNUTLS_E_SUCCESS){

511

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

512

safer_gnutls_strerror(ret));

513

return -1;

514

}

515

516

708

if(debug){

517

709

/* "Use a log level over 10 to enable all debugging options."

518

710

* - GnuTLS manual

526

718

if(ret != GNUTLS_E_SUCCESS){

527

719

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

528

720

safer_gnutls_strerror(ret));

529

gnutls_global_deinit();

530

721

return -1;

531

722

}

532

723

557

748

safer_gnutls_strerror(ret));

558

749

goto globalfail;

559

750

}

560

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

561

if(ret != GNUTLS_E_SUCCESS){

562

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

563

safer_gnutls_strerror(ret));

564

goto globalfail;

565

}

566

751

/* If a Diffie-Hellman parameters file was given, try to use it */

752

if(dhparamsfilename != NULL){

753

gnutls_datum_t params = { .data = NULL, .size = 0 };

754

do {

755

int dhpfile = open(dhparamsfilename, O_RDONLY);

756

if(dhpfile == -1){

757

perror_plus("open");

758

dhparamsfilename = NULL;

759

break;

760

}

761

size_t params_capacity = 0;

762

while(true){

763

params_capacity = incbuffer((char **)&params.data,

764

(size_t)params.size,

765

(size_t)params_capacity);

766

if(params_capacity == 0){

767

perror_plus("incbuffer");

768

free(params.data);

769

params.data = NULL;

770

dhparamsfilename = NULL;

771

break;

772

}

773

ssize_t bytes_read = read(dhpfile,

774

params.data + params.size,

775

BUFFER_SIZE);

776

/* EOF */

777

if(bytes_read == 0){

778

break;

779

}

780

/* check bytes_read for failure */

781

if(bytes_read < 0){

782

perror_plus("read");

783

free(params.data);

784

params.data = NULL;

785

dhparamsfilename = NULL;

786

break;

787

}

788

params.size += (unsigned int)bytes_read;

789

}

790

ret = close(dhpfile);

791

if(ret == -1){

792

perror_plus("close");

793

}

794

if(params.data == NULL){

795

dhparamsfilename = NULL;

796

}

797

if(dhparamsfilename == NULL){

798

break;

799

}

800

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

801

GNUTLS_X509_FMT_PEM);

802

if(ret != GNUTLS_E_SUCCESS){

803

fprintf_plus(stderr, "Failed to parse DH parameters in file"

804

" \"%s\": %s\n", dhparamsfilename,

805

safer_gnutls_strerror(ret));

806

dhparamsfilename = NULL;

807

}

808

free(params.data);

809

} while(false);

810

}

811

if(dhparamsfilename == NULL){

812

if(mc->dh_bits == 0){

813

/* Find out the optimal number of DH bits */

814

/* Try to read the private key file */

815

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

816

do {

817

int secfile = open(seckeyfilename, O_RDONLY);

818

if(secfile == -1){

819

perror_plus("open");

820

break;

821

}

822

size_t buffer_capacity = 0;

823

while(true){

824

buffer_capacity = incbuffer((char **)&buffer.data,

825

(size_t)buffer.size,

826

(size_t)buffer_capacity);

827

if(buffer_capacity == 0){

828

perror_plus("incbuffer");

829

free(buffer.data);

830

buffer.data = NULL;

831

break;

832

}

833

ssize_t bytes_read = read(secfile,

834

buffer.data + buffer.size,

835

BUFFER_SIZE);

836

/* EOF */

837

if(bytes_read == 0){

838

break;

839

}

840

/* check bytes_read for failure */

841

if(bytes_read < 0){

842

perror_plus("read");

843

free(buffer.data);

844

buffer.data = NULL;

845

break;

846

}

847

buffer.size += (unsigned int)bytes_read;

848

}

849

close(secfile);

850

} while(false);

851

/* If successful, use buffer to parse private key */

852

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

853

if(buffer.data != NULL){

854

{

855

gnutls_openpgp_privkey_t privkey = NULL;

856

ret = gnutls_openpgp_privkey_init(&privkey);

857

if(ret != GNUTLS_E_SUCCESS){

858

fprintf_plus(stderr, "Error initializing OpenPGP key"

859

" structure: %s",

860

safer_gnutls_strerror(ret));

861

free(buffer.data);

862

buffer.data = NULL;

863

} else {

864

ret = gnutls_openpgp_privkey_import

865

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

866

if(ret != GNUTLS_E_SUCCESS){

867

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

868

safer_gnutls_strerror(ret));

869

privkey = NULL;

870

}

871

free(buffer.data);

872

buffer.data = NULL;

873

if(privkey != NULL){

874

/* Use private key to suggest an appropriate

875

sec_param */

876

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

877

gnutls_openpgp_privkey_deinit(privkey);

878

if(debug){

879

fprintf_plus(stderr, "This OpenPGP key implies using"

880

" a GnuTLS security parameter \"%s\".\n",

881

safe_string(gnutls_sec_param_get_name

882

(sec_param)));

883

}

884

}

885

}

886

}

887

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

888

/* Err on the side of caution */

889

sec_param = GNUTLS_SEC_PARAM_ULTRA;

890

if(debug){

891

fprintf_plus(stderr, "Falling back to security parameter"

892

" \"%s\"\n",

893

safe_string(gnutls_sec_param_get_name

894

(sec_param)));

895

}

896

}

897

}

898

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

899

if(uret != 0){

900

mc->dh_bits = uret;

901

if(debug){

902

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

903

" implies %u DH bits; using that.\n",

904

safe_string(gnutls_sec_param_get_name

905

(sec_param)),

906

mc->dh_bits);

907

}

908

} else {

909

fprintf_plus(stderr, "Failed to get implied number of DH"

910

" bits for security parameter \"%s\"): %s\n",

911

safe_string(gnutls_sec_param_get_name

912

(sec_param)),

913

safer_gnutls_strerror(ret));

914

goto globalfail;

915

}

916

} else if(debug){

917

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

918

mc->dh_bits);

919

}

920

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

921

if(ret != GNUTLS_E_SUCCESS){

922

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

923

" bits): %s\n", mc->dh_bits,

924

safer_gnutls_strerror(ret));

925

goto globalfail;

926

}

927

}

567

928

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

568

929

569

930

return 0;

571

932

globalfail:

572

933

573

934

gnutls_certificate_free_credentials(mc->cred);

574

gnutls_global_deinit();

575

935

gnutls_dh_params_deinit(mc->dh_params);

576

936

return -1;

577

937

}

629

989

/* ignore client certificate if any. */

630

990

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

631

991

632

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

633

634

992

return 0;

635

993

}

636

994

638

996

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

639

997

__attribute__((unused)) const char *txt){}

640

998

999

/* Helper function to add_local_route() and delete_local_route() */

1000

__attribute__((nonnull, warn_unused_result))

1001

static bool add_delete_local_route(const bool add,

1002

const char *address,

1003

AvahiIfIndex if_index){

1004

int ret;

1005

char helper[] = "mandos-client-iprouteadddel";

1006

char add_arg[] = "add";

1007

char delete_arg[] = "delete";

1008

char debug_flag[] = "--debug";

1009

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1010

if(pluginhelperdir == NULL){

1011

if(debug){

1012

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1013

" variable not set; cannot run helper\n");

1014

}

1015

return false;

1016

}

1017

1018

char interface[IF_NAMESIZE];

1019

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1020

perror_plus("if_indextoname");

1021

return false;

1022

}

1023

1024

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1025

if(devnull == -1){

1026

perror_plus("open(\"/dev/null\", O_RDONLY)");

1027

return false;

1028

}

1029

pid_t pid = fork();

1030

if(pid == 0){

1031

/* Child */

1032

/* Raise privileges */

1033

errno = raise_privileges_permanently();

1034

if(errno != 0){

1035

perror_plus("Failed to raise privileges");

1036

/* _exit(EX_NOPERM); */

1037

} else {

1038

/* Set group */

1039

errno = 0;

1040

ret = setgid(0);

1041

if(ret == -1){

1042

perror_plus("setgid");

1043

_exit(EX_NOPERM);

1044

}

1045

/* Reset supplementary groups */

1046

errno = 0;

1047

ret = setgroups(0, NULL);

1048

if(ret == -1){

1049

perror_plus("setgroups");

1050

_exit(EX_NOPERM);

1051

}

1052

}

1053

ret = dup2(devnull, STDIN_FILENO);

1054

if(ret == -1){

1055

perror_plus("dup2(devnull, STDIN_FILENO)");

1056

_exit(EX_OSERR);

1057

}

1058

ret = close(devnull);

1059

if(ret == -1){

1060

perror_plus("close");

1061

_exit(EX_OSERR);

1062

}

1063

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1064

if(ret == -1){

1065

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1066

_exit(EX_OSERR);

1067

}

1068

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

1069

O_RDONLY

1070

| O_DIRECTORY

1071

| O_PATH

1072

| O_CLOEXEC));

1073

if(helperdir_fd == -1){

1074

perror_plus("open");

1075

_exit(EX_UNAVAILABLE);

1076

}

1077

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

1078

helper, O_RDONLY));

1079

if(helper_fd == -1){

1080

perror_plus("openat");

1081

close(helperdir_fd);

1082

_exit(EX_UNAVAILABLE);

1083

}

1084

close(helperdir_fd);

1085

#ifdef __GNUC__

1086

#pragma GCC diagnostic push

1087

#pragma GCC diagnostic ignored "-Wcast-qual"

1088

#endif

1089

if(fexecve(helper_fd, (char *const [])

1090

{ helper, add ? add_arg : delete_arg, (char *)address,

1091

interface, debug ? debug_flag : NULL, NULL },

1092

environ) == -1){

1093

#ifdef __GNUC__

1094

#pragma GCC diagnostic pop

1095

#endif

1096

perror_plus("fexecve");

1097

_exit(EXIT_FAILURE);

1098

}

1099

}

1100

if(pid == -1){

1101

perror_plus("fork");

1102

return false;

1103

}

1104

int status;

1105

pid_t pret = -1;

1106

errno = 0;

1107

do {

1108

pret = waitpid(pid, &status, 0);

1109

if(pret == -1 and errno == EINTR and quit_now){

1110

int errno_raising = 0;

1111

if((errno = raise_privileges()) != 0){

1112

errno_raising = errno;

1113

perror_plus("Failed to raise privileges in order to"

1114

" kill helper program");

1115

}

1116

if(kill(pid, SIGTERM) == -1){

1117

perror_plus("kill");

1118

}

1119

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

1120

perror_plus("Failed to lower privileges after killing"

1121

" helper program");

1122

}

1123

return false;

1124

}

1125

} while(pret == -1 and errno == EINTR);

1126

if(pret == -1){

1127

perror_plus("waitpid");

1128

return false;

1129

}

1130

if(WIFEXITED(status)){

1131

if(WEXITSTATUS(status) != 0){

1132

fprintf_plus(stderr, "Error: iprouteadddel exited"

1133

" with status %d\n", WEXITSTATUS(status));

1134

return false;

1135

}

1136

return true;

1137

}

1138

if(WIFSIGNALED(status)){

1139

fprintf_plus(stderr, "Error: iprouteadddel died by"

1140

" signal %d\n", WTERMSIG(status));

1141

return false;

1142

}

1143

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1144

return false;

1145

}

1146

1147

__attribute__((nonnull, warn_unused_result))

1148

static bool add_local_route(const char *address,

1149

AvahiIfIndex if_index){

1150

if(debug){

1151

fprintf_plus(stderr, "Adding route to %s\n", address);

1152

}

1153

return add_delete_local_route(true, address, if_index);

1154

}

1155

1156

__attribute__((nonnull, warn_unused_result))

1157

static bool delete_local_route(const char *address,

1158

AvahiIfIndex if_index){

1159

if(debug){

1160

fprintf_plus(stderr, "Removing route to %s\n", address);

1161

}

1162

return add_delete_local_route(false, address, if_index);

1163

}

1164

641

1165

/* Called when a Mandos server is found */

642

1166

__attribute__((nonnull, warn_unused_result))

643

1167

static int start_mandos_communication(const char *ip, in_port_t port,

654

1178

int retval = -1;

655

1179

gnutls_session_t session;

656

1180

int pf; /* Protocol family */

1181

bool route_added = false;

657

1182

658

1183

errno = 0;

659

1184

681

1206

bool match = false;

682

1207

{

683

1208

char *interface = NULL;

684

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

685

interface))){

1209

while((interface = argz_next(mc->interfaces,

1210

mc->interfaces_size,

1211

interface))){

686

1212

if(if_nametoindex(interface) == (unsigned int)if_index){

687

1213

match = true;

688

1214

break;

717

1243

PRIuMAX "\n", ip, (uintmax_t)port);

718

1244

}

719

1245

720

tcp_sd = socket(pf, SOCK_STREAM, 0);

1246

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

721

1247

if(tcp_sd < 0){

722

1248

int e = errno;

723

1249

perror_plus("socket");

730

1256

goto mandos_end;

731

1257

}

732

1258

733

memset(&to, 0, sizeof(to));

734

1259

if(af == AF_INET6){

735

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

736

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

1260

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1261

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1262

ret = inet_pton(af, ip, &to6->sin6_addr);

737

1263

} else { /* IPv4 */

738

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

739

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

1264

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1265

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1266

ret = inet_pton(af, ip, &to4->sin_addr);

740

1267

}

741

1268

if(ret < 0 ){

742

1269

int e = errno;

812

1339

goto mandos_end;

813

1340

}

814

1341

815

if(af == AF_INET6){

816

ret = connect(tcp_sd, (struct sockaddr *)&to,

817

sizeof(struct sockaddr_in6));

818

} else {

819

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

820

sizeof(struct sockaddr_in));

821

}

822

if(ret < 0){

823

if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

824

int e = errno;

825

perror_plus("connect");

826

errno = e;

827

}

828

goto mandos_end;

829

}

830

831

if(quit_now){

832

errno = EINTR;

833

goto mandos_end;

1342

while(true){

1343

if(af == AF_INET6){

1344

ret = connect(tcp_sd, (struct sockaddr *)&to,

1345

sizeof(struct sockaddr_in6));

1346

} else {

1347

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1348

sizeof(struct sockaddr_in));

1349

}

1350

if(ret < 0){

1351

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1352

and if_index != AVAHI_IF_UNSPEC

1353

and connect_to == NULL

1354

and not route_added and

1355

((af == AF_INET6 and not

1356

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1357

&to)->sin6_addr)))

1358

or (af == AF_INET and

1359

/* Not a a IPv4LL address */

1360

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1361

& 0xFFFF0000L) != 0xA9FE0000L))){

1362

/* Work around Avahi bug - Avahi does not announce link-local

1363

addresses if it has a global address, so local hosts with

1364

*only* a link-local address (e.g. Mandos clients) cannot

1365

connect to a Mandos server announced by Avahi on a server

1366

host with a global address. Work around this by retrying

1367

with an explicit route added with the server's address.

1368

1369

Avahi bug reference:

1370

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1371

https://bugs.debian.org/587961

1372

*/

1373

if(debug){

1374

fprintf_plus(stderr, "Mandos server unreachable, trying"

1375

" direct route\n");

1376

}

1377

int e = errno;

1378

route_added = add_local_route(ip, if_index);

1379

if(route_added){

1380

continue;

1381

}

1382

errno = e;

1383

}

1384

if(errno != ECONNREFUSED or debug){

1385

int e = errno;

1386

perror_plus("connect");

1387

errno = e;

1388

}

1389

goto mandos_end;

1390

}

1391

1392

if(quit_now){

1393

errno = EINTR;

1394

goto mandos_end;

1395

}

1396

break;

834

1397

}

835

1398

836

1399

const char *out = mandos_protocol_version;

990

1553

&decrypted_buffer, mc);

991

1554

if(decrypted_buffer_size >= 0){

992

1555

1556

clearerr(stdout);

993

1557

written = 0;

994

1558

while(written < (size_t) decrypted_buffer_size){

995

1559

if(quit_now){

1011

1575

}

1012

1576

written += (size_t)ret;

1013

1577

}

1578

ret = fflush(stdout);

1579

if(ret != 0){

1580

int e = errno;

1581

if(debug){

1582

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1583

strerror(errno));

1584

}

1585

errno = e;

1586

goto mandos_end;

1587

}

1014

1588

retval = 0;

1015

1589

}

1016

1590

}

1019

1593

1020

1594

mandos_end:

1021

1595

{

1596

if(route_added){

1597

if(not delete_local_route(ip, if_index)){

1598

fprintf_plus(stderr, "Failed to delete local route to %s on"

1599

" interface %d", ip, if_index);

1600

}

1601

}

1022

1602

int e = errno;

1023

1603

free(decrypted_buffer);

1024

1604

free(buffer);

1025

1605

if(tcp_sd >= 0){

1026

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

1606

ret = close(tcp_sd);

1027

1607

}

1028

1608

if(ret == -1){

1029

1609

if(e == 0){

1041

1621

return retval;

1042

1622

}

1043

1623

1044

__attribute__((nonnull))

1045

1624

static void resolve_callback(AvahiSServiceResolver *r,

1046

1625

AvahiIfIndex interface,

1047

1626

AvahiProtocol proto,

1064

1643

timed out */

1065

1644

1066

1645

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1067

1647

return;

1068

1648

}

1069

1649

1183

1763

__attribute__((nonnull, warn_unused_result))

1184

1764

bool get_flags(const char *ifname, struct ifreq *ifr){

1185

1765

int ret;

1186

error_t ret_errno;

1766

int old_errno;

1187

1767

1188

1768

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1189

1769

if(s < 0){

1190

ret_errno = errno;

1770

old_errno = errno;

1191

1771

perror_plus("socket");

1192

errno = ret_errno;

1772

errno = old_errno;

1193

1773

return false;

1194

1774

}

1195

strcpy(ifr->ifr_name, ifname);

1775

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1776

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1196

1777

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1197

1778

if(ret == -1){

1198

1779

if(debug){

1199

ret_errno = errno;

1780

old_errno = errno;

1200

1781

perror_plus("ioctl SIOCGIFFLAGS");

1201

errno = ret_errno;

1782

errno = old_errno;

1783

}

1784

if((close(s) == -1) and debug){

1785

old_errno = errno;

1786

perror_plus("close");

1787

errno = old_errno;

1202

1788

}

1203

1789

return false;

1204

1790

}

1791

if((close(s) == -1) and debug){

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1205

1796

return true;

1206

1797

}

1207

1798

1335

1926

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1336

1927

"abcdefghijklmnopqrstuvwxyz"

1337

1928

"0123456789"

1338

"_-");

1929

"_.-");

1339

1930

if((direntry->d_name)[sret] != '\0'){

1340

1931

/* Contains non-allowed characters */

1341

1932

if(debug){

1345

1936

return 0;

1346

1937

}

1347

1938

1348

char *fullname = NULL;

1349

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1350

if(ret < 0){

1351

perror_plus("asprintf");

1352

return 0;

1353

}

1354

1355

ret = stat(fullname, &st);

1939

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1356

1940

if(ret == -1){

1357

1941

if(debug){

1358

1942

perror_plus("Could not stat hook");

1456

2040

}

1457

2041

}

1458

2042

1459

/* Set effective uid to 0, return errno */

1460

__attribute__((warn_unused_result))

1461

error_t raise_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

if(seteuid(0) == -1){

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Set effective and real user ID to 0. Return errno. */

1473

__attribute__((warn_unused_result))

1474

error_t raise_privileges_permanently(void){

1475

error_t old_errno = errno;

1476

error_t ret_errno = raise_privileges();

1477

if(ret_errno != 0){

1478

errno = old_errno;

1479

return ret_errno;

1480

}

1481

if(setuid(0) == -1){

1482

ret_errno = errno;

1483

perror_plus("seteuid");

1484

}

1485

errno = old_errno;

1486

return ret_errno;

1487

}

1488

1489

/* Set effective user ID to unprivileged saved user ID */

1490

__attribute__((warn_unused_result))

1491

error_t lower_privileges(void){

1492

error_t old_errno = errno;

1493

error_t ret_errno = 0;

1494

if(seteuid(uid) == -1){

1495

ret_errno = errno;

1496

perror_plus("seteuid");

1497

}

1498

errno = old_errno;

1499

return ret_errno;

1500

}

1501

1502

/* Lower privileges permanently */

1503

__attribute__((warn_unused_result))

1504

error_t lower_privileges_permanently(void){

1505

error_t old_errno = errno;

1506

error_t ret_errno = 0;

1507

if(setuid(uid) == -1){

1508

ret_errno = errno;

1509

perror_plus("setuid");

1510

}

1511

errno = old_errno;

1512

return ret_errno;

1513

}

1514

1515

2043

__attribute__((nonnull))

1516

2044

void run_network_hooks(const char *mode, const char *interface,

1517

2045

const float delay){

1518

struct dirent **direntries;

1519

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1520

alphasort);

2046

struct dirent **direntries = NULL;

2047

if(hookdir_fd == -1){

2048

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2049

| O_CLOEXEC);

2050

if(hookdir_fd == -1){

2051

if(errno == ENOENT){

2052

if(debug){

2053

fprintf_plus(stderr, "Network hook directory \"%s\" not"

2054

" found\n", hookdir);

2055

}

2056

} else {

2057

perror_plus("open");

2058

}

2059

return;

2060

}

2061

}

2062

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

2063

if(devnull == -1){

2064

perror_plus("open(\"/dev/null\", O_RDONLY)");

2065

return;

2066

}

2067

int numhooks = scandirat(hookdir_fd, ".", &direntries,

2068

runnable_hook, alphasort);

1521

2069

if(numhooks == -1){

1522

if(errno == ENOENT){

1523

if(debug){

1524

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1525

" found\n", hookdir);

1526

}

1527

} else {

1528

perror_plus("scandir");

2070

perror_plus("scandir");

2071

close(devnull);

2072

return;

2073

}

2074

struct dirent *direntry;

2075

int ret;

2076

for(int i = 0; i < numhooks; i++){

2077

direntry = direntries[i];

2078

if(debug){

2079

fprintf_plus(stderr, "Running network hook \"%s\"\n",

2080

direntry->d_name);

1529

2081

}

1530

} else {

1531

struct dirent *direntry;

1532

int ret;

1533

int devnull = open("/dev/null", O_RDONLY);

1534

for(int i = 0; i < numhooks; i++){

1535

direntry = direntries[i];

1536

char *fullname = NULL;

1537

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1538

if(ret < 0){

2082

pid_t hook_pid = fork();

2083

if(hook_pid == 0){

2084

/* Child */

2085

/* Raise privileges */

2086

errno = raise_privileges_permanently();

2087

if(errno != 0){

2088

perror_plus("Failed to raise privileges");

2089

_exit(EX_NOPERM);

2090

}

2091

/* Set group */

2092

errno = 0;

2093

ret = setgid(0);

2094

if(ret == -1){

2095

perror_plus("setgid");

2096

_exit(EX_NOPERM);

2097

}

2098

/* Reset supplementary groups */

2099

errno = 0;

2100

ret = setgroups(0, NULL);

2101

if(ret == -1){

2102

perror_plus("setgroups");

2103

_exit(EX_NOPERM);

2104

}

2105

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

2106

if(ret == -1){

2107

perror_plus("setenv");

2108

_exit(EX_OSERR);

2109

}

2110

ret = setenv("DEVICE", interface, 1);

2111

if(ret == -1){

2112

perror_plus("setenv");

2113

_exit(EX_OSERR);

2114

}

2115

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

2116

if(ret == -1){

2117

perror_plus("setenv");

2118

_exit(EX_OSERR);

2119

}

2120

ret = setenv("MODE", mode, 1);

2121

if(ret == -1){

2122

perror_plus("setenv");

2123

_exit(EX_OSERR);

2124

}

2125

char *delaystring;

2126

ret = asprintf(&delaystring, "%f", (double)delay);

2127

if(ret == -1){

1539

2128

perror_plus("asprintf");

1540

continue;

1541

}

1542

if(debug){

1543

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1544

direntry->d_name);

1545

}

1546

pid_t hook_pid = fork();

1547

if(hook_pid == 0){

1548

/* Child */

1549

/* Raise privileges */

1550

if(raise_privileges_permanently() != 0){

1551

perror_plus("Failed to raise privileges");

1552

_exit(EX_NOPERM);

1553

}

1554

/* Set group */

1555

errno = 0;

1556

ret = setgid(0);

1557

if(ret == -1){

1558

perror_plus("setgid");

1559

_exit(EX_NOPERM);

1560

}

1561

/* Reset supplementary groups */

1562

errno = 0;

1563

ret = setgroups(0, NULL);

1564

if(ret == -1){

1565

perror_plus("setgroups");

1566

_exit(EX_NOPERM);

1567

}

1568

ret = dup2(devnull, STDIN_FILENO);

1569

if(ret == -1){

1570

perror_plus("dup2(devnull, STDIN_FILENO)");

1571

_exit(EX_OSERR);

1572

}

1573

ret = close(devnull);

1574

if(ret == -1){

1575

perror_plus("close");

1576

_exit(EX_OSERR);

1577

}

1578

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1579

if(ret == -1){

1580

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1581

_exit(EX_OSERR);

1582

}

1583

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1584

if(ret == -1){

1585

perror_plus("setenv");

1586

_exit(EX_OSERR);

1587

}

1588

ret = setenv("DEVICE", interface, 1);

1589

if(ret == -1){

1590

perror_plus("setenv");

1591

_exit(EX_OSERR);

1592

}

1593

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1594

if(ret == -1){

1595

perror_plus("setenv");

1596

_exit(EX_OSERR);

1597

}

1598

ret = setenv("MODE", mode, 1);

1599

if(ret == -1){

1600

perror_plus("setenv");

1601

_exit(EX_OSERR);

1602

}

1603

char *delaystring;

1604

ret = asprintf(&delaystring, "%f", (double)delay);

1605

if(ret == -1){

1606

perror_plus("asprintf");

1607

_exit(EX_OSERR);

1608

}

1609

ret = setenv("DELAY", delaystring, 1);

1610

if(ret == -1){

1611

free(delaystring);

1612

perror_plus("setenv");

1613

_exit(EX_OSERR);

1614

}

2129

_exit(EX_OSERR);

2130

}

2131

ret = setenv("DELAY", delaystring, 1);

2132

if(ret == -1){

1615

2133

free(delaystring);

1616

if(connect_to != NULL){

1617

ret = setenv("CONNECT", connect_to, 1);

1618

if(ret == -1){

1619

perror_plus("setenv");

1620

_exit(EX_OSERR);

1621

}

1622

}

1623

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1624

perror_plus("execl");

1625

_exit(EXIT_FAILURE);

1626

}

2134

perror_plus("setenv");

2135

_exit(EX_OSERR);

2136

}

2137

free(delaystring);

2138

if(connect_to != NULL){

2139

ret = setenv("CONNECT", connect_to, 1);

2140

if(ret == -1){

2141

perror_plus("setenv");

2142

_exit(EX_OSERR);

2143

}

2144

}

2145

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2146

direntry->d_name,

2147

O_RDONLY));

2148

if(hook_fd == -1){

2149

perror_plus("openat");

2150

_exit(EXIT_FAILURE);

2151

}

2152

if(close(hookdir_fd) == -1){

2153

perror_plus("close");

2154

_exit(EXIT_FAILURE);

2155

}

2156

ret = dup2(devnull, STDIN_FILENO);

2157

if(ret == -1){

2158

perror_plus("dup2(devnull, STDIN_FILENO)");

2159

_exit(EX_OSERR);

2160

}

2161

ret = close(devnull);

2162

if(ret == -1){

2163

perror_plus("close");

2164

_exit(EX_OSERR);

2165

}

2166

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2167

if(ret == -1){

2168

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2169

_exit(EX_OSERR);

2170

}

2171

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2172

environ) == -1){

2173

perror_plus("fexecve");

2174

_exit(EXIT_FAILURE);

2175

}

2176

} else {

2177

if(hook_pid == -1){

2178

perror_plus("fork");

2179

free(direntry);

2180

continue;

2181

}

2182

int status;

2183

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2184

perror_plus("waitpid");

2185

free(direntry);

2186

continue;

2187

}

2188

if(WIFEXITED(status)){

2189

if(WEXITSTATUS(status) != 0){

2190

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2191

" with status %d\n", direntry->d_name,

2192

WEXITSTATUS(status));

2193

free(direntry);

2194

continue;

2195

}

2196

} else if(WIFSIGNALED(status)){

2197

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2198

" signal %d\n", direntry->d_name,

2199

WTERMSIG(status));

2200

free(direntry);

2201

continue;

1627

2202

} else {

1628

int status;

1629

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1630

perror_plus("waitpid");

1631

free(fullname);

1632

continue;

1633

}

1634

if(WIFEXITED(status)){

1635

if(WEXITSTATUS(status) != 0){

1636

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1637

" with status %d\n", direntry->d_name,

1638

WEXITSTATUS(status));

1639

free(fullname);

1640

continue;

1641

}

1642

} else if(WIFSIGNALED(status)){

1643

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1644

" signal %d\n", direntry->d_name,

1645

WTERMSIG(status));

1646

free(fullname);

1647

continue;

1648

} else {

1649

fprintf_plus(stderr, "Warning: network hook \"%s\""

1650

" crashed\n", direntry->d_name);

1651

free(fullname);

1652

continue;

1653

}

1654

}

1655

free(fullname);

1656

if(debug){

1657

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1658

direntry->d_name);

1659

}

1660

}

1661

close(devnull);

1662

}

2203

fprintf_plus(stderr, "Warning: network hook \"%s\""

2204

" crashed\n", direntry->d_name);

2205

free(direntry);

2206

continue;

2207

}

2208

}

2209

if(debug){

2210

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2211

direntry->d_name);

2212

}

2213

free(direntry);

2214

}

2215

free(direntries);

2216

if(close(hookdir_fd) == -1){

2217

perror_plus("close");

2218

} else {

2219

hookdir_fd = -1;

2220

}

2221

close(devnull);

1663

2222

}

1664

2223

1665

2224

__attribute__((nonnull, warn_unused_result))

1666

error_t bring_up_interface(const char *const interface,

1667

const float delay){

1668

error_t old_errno = errno;

2225

int bring_up_interface(const char *const interface,

2226

const float delay){

2227

int old_errno = errno;

1669

2228

int ret;

1670

2229

struct ifreq network;

1671

2230

unsigned int if_index = if_nametoindex(interface);

1681

2240

}

1682

2241

1683

2242

if(not interface_is_up(interface)){

1684

error_t ret_errno = 0, ioctl_errno = 0;

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

1685

2245

if(not get_flags(interface, &network)){

1686

2246

ret_errno = errno;

1687

2247

fprintf_plus(stderr, "Failed to get flags for interface "

1700

2260

}

1701

2261

1702

2262

if(quit_now){

1703

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2263

ret = close(sd);

1704

2264

if(ret == -1){

1705

2265

perror_plus("close");

1706

2266

}

1715

2275

1716

2276

/* Raise privileges */

1717

2277

ret_errno = raise_privileges();

2278

if(ret_errno != 0){

2279

errno = ret_errno;

2280

perror_plus("Failed to raise privileges");

2281

}

2282

2283

#ifdef __linux__

2284

int ret_linux;

1718

2285

bool restore_loglevel = false;

1719

if(ret_errno != 0){

1720

perror_plus("Failed to raise privileges");

1721

}

1722

#ifdef __linux__

1723

int ret_linux;

1724

2286

if(ret_errno == 0){

1725

2287

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1726

2288

messages about the network interface to mess up the prompt */

1754

2316

}

1755

2317

1756

2318

/* Close the socket */

1757

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2319

ret = close(sd);

1758

2320

if(ret == -1){

1759

2321

perror_plus("close");

1760

2322

}

1772

2334

1773

2335

/* Sleep checking until interface is running.

1774

2336

Check every 0.25s, up to total time of delay */

1775

for(int i=0; i < delay * 4; i++){

2337

for(int i = 0; i < delay * 4; i++){

1776

2338

if(interface_is_running(interface)){

1777

2339

break;

1778

2340

}

1788

2350

}

1789

2351

1790

2352

__attribute__((nonnull, warn_unused_result))

1791

error_t take_down_interface(const char *const interface){

1792

error_t old_errno = errno;

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

1793

2355

struct ifreq network;

1794

2356

unsigned int if_index = if_nametoindex(interface);

1795

2357

if(if_index == 0){

1798

2360

return ENXIO;

1799

2361

}

1800

2362

if(interface_is_up(interface)){

1801

error_t ret_errno = 0, ioctl_errno = 0;

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

1802

2365

if(not get_flags(interface, &network) and debug){

1803

2366

ret_errno = errno;

1804

2367

fprintf_plus(stderr, "Failed to get flags for interface "

1824

2387

/* Raise privileges */

1825

2388

ret_errno = raise_privileges();

1826

2389

if(ret_errno != 0){

2390

errno = ret_errno;

1827

2391

perror_plus("Failed to raise privileges");

1828

2392

}

2393

1829

2394

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

1830

2395

ioctl_errno = errno;

1831

2396

1840

2405

}

1841

2406

1842

2407

/* Close the socket */

1843

int ret = (int)TEMP_FAILURE_RETRY(close(sd));

2408

int ret = close(sd);

1844

2409

if(ret == -1){

1845

2410

perror_plus("close");

1846

2411

}

1861

2426

}

1862

2427

1863

2428

int main(int argc, char *argv[]){

1864

mandos_context mc = { .server = NULL, .dh_bits = 1024,

1865

.priority = "SECURE256:!CTYPE-X.509:"

1866

"+CTYPE-OPENPGP", .current_server = NULL,

1867

.interfaces = NULL, .interfaces_size = 0 };

2429

mandos_context mc = { .server = NULL, .dh_bits = 0,

2430

.priority = "SECURE256:!CTYPE-X.509"

2431

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2432

.current_server = NULL, .interfaces = NULL,

2433

.interfaces_size = 0 };

1868

2434

AvahiSServiceBrowser *sb = NULL;

1869

2435

error_t ret_errno;

1870

2436

int ret;

1879

2445

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1880

2446

const char *seckey = PATHDIR "/" SECKEY;

1881

2447

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

1882

2449

char *interfaces_hooks = NULL;

1883

2450

1884

2451

bool gnutls_initialized = false;

1937

2504

.doc = "Bit length of the prime number used in the"

1938

2505

" Diffie-Hellman key exchange",

1939

2506

.group = 2 },

2507

{ .name = "dh-params", .key = 134,

2508

.arg = "FILE",

2509

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2510

" for the Diffie-Hellman key exchange",

2511

.group = 2 },

1940

2512

{ .name = "priority", .key = 130,

1941

2513

.arg = "STRING",

1942

2514

.doc = "GnuTLS priority string for the TLS handshake",

1997

2569

}

1998

2570

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

1999

2571

break;

2572

case 134: /* --dh-params */

2573

dh_params_file = arg;

2574

break;

2000

2575

case 130: /* --priority */

2001

2576

mc.priority = arg;

2002

2577

break;

2042

2617

.args_doc = "",

2043

2618

.doc = "Mandos client -- Get and decrypt"

2044

2619

" passwords from a Mandos server" };

2045

ret = argp_parse(&argp, argc, argv,

2046

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2047

switch(ret){

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

2048

2623

case 0:

2049

2624

break;

2050

2625

case ENOMEM:

2051

2626

default:

2052

errno = ret;

2627

errno = ret_errno;

2053

2628

perror_plus("argp_parse");

2054

2629

exitcode = EX_OSERR;

2055

2630

goto end;

2058

2633

goto end;

2059

2634

}

2060

2635

}

2061

2636

2062

2637

{

2063

2638

/* Work around Debian bug #633582:

2064

<http://bugs.debian.org/633582> */

2639

<https://bugs.debian.org/633582> */

2065

2640

2066

2641

/* Re-raise privileges */

2067

ret_errno = raise_privileges();

2068

if(ret_errno != 0){

2069

errno = ret_errno;

2642

ret = raise_privileges();

2643

if(ret != 0){

2644

errno = ret;

2070

2645

perror_plus("Failed to raise privileges");

2071

2646

} else {

2072

2647

struct stat st;

2088

2663

}

2089

2664

}

2090

2665

}

2091

TEMP_FAILURE_RETRY(close(seckey_fd));

2666

close(seckey_fd);

2092

2667

}

2093

2668

}

2094

2669

2095

2670

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2096

2671

int pubkey_fd = open(pubkey, O_RDONLY);

2097

2672

if(pubkey_fd == -1){

2109

2684

}

2110

2685

}

2111

2686

}

2112

TEMP_FAILURE_RETRY(close(pubkey_fd));

2113

}

2114

}

2115

2687

close(pubkey_fd);

2688

}

2689

}

2690

2691

if(dh_params_file != NULL

2692

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2693

int dhparams_fd = open(dh_params_file, O_RDONLY);

2694

if(dhparams_fd == -1){

2695

perror_plus("open");

2696

} else {

2697

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2698

if(ret == -1){

2699

perror_plus("fstat");

2700

} else {

2701

if(S_ISREG(st.st_mode)

2702

and st.st_uid == 0 and st.st_gid == 0){

2703

ret = fchown(dhparams_fd, uid, gid);

2704

if(ret == -1){

2705

perror_plus("fchown");

2706

}

2707

}

2708

}

2709

close(dhparams_fd);

2710

}

2711

}

2712

2116

2713

/* Lower privileges */

2117

ret_errno = lower_privileges();

2118

if(ret_errno != 0){

2119

errno = ret_errno;

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2120

2717

perror_plus("Failed to lower privileges");

2121

2718

}

2122

2719

}

2235

2832

2236

2833

/* If no interfaces were specified, make a list */

2237

2834

if(mc.interfaces == NULL){

2238

struct dirent **direntries;

2835

struct dirent **direntries = NULL;

2239

2836

/* Look for any good interfaces */

2240

2837

ret = scandir(sys_class_net, &direntries, good_interface,

2241

2838

alphasort);

2247

2844

if(ret_errno != 0){

2248

2845

errno = ret_errno;

2249

2846

perror_plus("argz_add");

2847

free(direntries[i]);

2250

2848

continue;

2251

2849

}

2252

2850

if(debug){

2253

2851

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2254

2852

direntries[i]->d_name);

2255

2853

}

2854

free(direntries[i]);

2256

2855

}

2257

2856

free(direntries);

2258

2857

} else {

2259

free(direntries);

2858

if(ret == 0){

2859

free(direntries);

2860

}

2260

2861

fprintf_plus(stderr, "Could not find a network interface\n");

2261

2862

exitcode = EXIT_FAILURE;

2262

2863

goto end;

2288

2889

errno = bring_up_interface(interface, delay);

2289

2890

if(not interface_was_up){

2290

2891

if(errno != 0){

2291

perror_plus("Failed to bring up interface");

2892

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2893

" %s\n", interface, strerror(errno));

2292

2894

} else {

2293

2895

errno = argz_add(&interfaces_to_take_down,

2294

2896

&interfaces_to_take_down_size,

2317

2919

goto end;

2318

2920

}

2319

2921

2320

ret = init_gnutls_global(pubkey, seckey, &mc);

2922

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2321

2923

if(ret == -1){

2322

2924

fprintf_plus(stderr, "init_gnutls_global failed\n");

2323

2925

exitcode = EX_UNAVAILABLE;

2445

3047

2446

3048

/* Allocate a new server */

2447

3049

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2448

&config, NULL, NULL, &ret_errno);

3050

&config, NULL, NULL, &ret);

2449

3051

2450

3052

/* Free the Avahi configuration data */

2451

3053

avahi_server_config_free(&config);

2454

3056

/* Check if creating the Avahi server object succeeded */

2455

3057

if(mc.server == NULL){

2456

3058

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2457

avahi_strerror(ret_errno));

3059

avahi_strerror(ret));

2458

3060

exitcode = EX_UNAVAILABLE;

2459

3061

goto end;

2460

3062

}

2484

3086

if(debug){

2485

3087

fprintf_plus(stderr, "Starting Avahi loop search\n");

2486

3088

}

2487

3089

2488

3090

ret = avahi_loop_with_timeout(simple_poll,

2489

3091

(int)(retry_interval * 1000), &mc);

2490

3092

if(debug){

2495

3097

end:

2496

3098

2497

3099

if(debug){

2498

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3100

if(signal_received){

3101

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

3102

argv[0], signal_received,

3103

strsignal(signal_received));

3104

} else {

3105

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3106

}

2499

3107

}

2500

3108

2501

3109

/* Cleanup things */

2512

3120

2513

3121

if(gnutls_initialized){

2514

3122

gnutls_certificate_free_credentials(mc.cred);

2515

gnutls_global_deinit();

2516

3123

gnutls_dh_params_deinit(mc.dh_params);

2517

3124

}

2518

3125

2526

3133

mc.current_server->prev->next = NULL;

2527

3134

while(mc.current_server != NULL){

2528

3135

server *next = mc.current_server->next;

3136

#ifdef __GNUC__

3137

#pragma GCC diagnostic push

3138

#pragma GCC diagnostic ignored "-Wcast-qual"

3139

#endif

3140

free((char *)(mc.current_server->ip));

3141

#ifdef __GNUC__

3142

#pragma GCC diagnostic pop

3143

#endif

2529

3144

free(mc.current_server);

2530

3145

mc.current_server = next;

2531

3146

}

2533

3148

2534

3149

/* Re-raise privileges */

2535

3150

{

2536

ret_errno = raise_privileges();

2537

if(ret_errno != 0){

3151

ret = raise_privileges();

3152

if(ret != 0){

3153

errno = ret;

2538

3154

perror_plus("Failed to raise privileges");

2539

3155

} else {

2540

3156

2545

3161

/* Take down the network interfaces which were brought up */

2546

3162

{

2547

3163

char *interface = NULL;

2548

while((interface=argz_next(interfaces_to_take_down,

2549

interfaces_to_take_down_size,

2550

interface))){

2551

ret_errno = take_down_interface(interface);

2552

if(ret_errno != 0){

2553

errno = ret_errno;

3164

while((interface = argz_next(interfaces_to_take_down,

3165

interfaces_to_take_down_size,

3166

interface))){

3167

ret = take_down_interface(interface);

3168

if(ret != 0){

3169

errno = ret;

2554

3170

perror_plus("Failed to take down interface");

2555

3171

}

2556

3172

}

2560

3176

}

2561

3177

}

2562

3178

}

2563

ret_errno = lower_privileges_permanently();

2564

if(ret_errno != 0){

3179

3180

ret = lower_privileges_permanently();

3181

if(ret != 0){

3182

errno = ret;

2565

3183

perror_plus("Failed to lower privileges permanently");

2566

3184

}

2567

3185

}

2569

3187

free(interfaces_to_take_down);

2570

3188

free(interfaces_hooks);

2571

3189

3190

void clean_dir_at(int base, const char * const dirname,

3191

uintmax_t level){

3192

struct dirent **direntries = NULL;

3193

int dret;

3194

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3195

O_RDONLY

3196

| O_NOFOLLOW

3197

| O_DIRECTORY

3198

| O_PATH));

3199

if(dir_fd == -1){

3200

perror_plus("open");

3201

return;

3202

}

3203

int numentries = scandirat(dir_fd, ".", &direntries,

3204

notdotentries, alphasort);

3205

if(numentries >= 0){

3206

for(int i = 0; i < numentries; i++){

3207

if(debug){

3208

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3209

dirname, direntries[i]->d_name);

3210

}

3211

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3212

if(dret == -1){

3213

if(errno == EISDIR){

3214

dret = unlinkat(dir_fd, direntries[i]->d_name,

3215

AT_REMOVEDIR);

3216

}

3217

if((dret == -1) and (errno == ENOTEMPTY)

3218

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3219

== 0) and (level == 0)){

3220

/* Recurse only in this special case */

3221

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3222

dret = 0;

3223

}

3224

if((dret == -1) and (errno != ENOENT)){

3225

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3226

direntries[i]->d_name, strerror(errno));

3227

}

3228

}

3229

free(direntries[i]);

3230

}

3231

3232

/* need to clean even if 0 because man page doesn't specify */

3233

free(direntries);

3234

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3235

if(dret == -1 and errno != ENOENT){

3236

perror_plus("rmdir");

3237

}

3238

} else {

3239

perror_plus("scandirat");

3240

}

3241

close(dir_fd);

3242

}

3243

2572

3244

/* Removes the GPGME temp directory and all files inside */

2573

3245

if(tempdir != NULL){

2574

struct dirent **direntries = NULL;

2575

struct dirent *direntry = NULL;

2576

int numentries = scandir(tempdir, &direntries, notdotentries,

2577

alphasort);

2578

if(numentries > 0){

2579

for(int i = 0; i < numentries; i++){

2580

direntry = direntries[i];

2581

char *fullname = NULL;

2582

ret = asprintf(&fullname, "%s/%s", tempdir,

2583

direntry->d_name);

2584

if(ret < 0){

2585

perror_plus("asprintf");

2586

continue;

2587

}

2588

ret = remove(fullname);

2589

if(ret == -1){

2590

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2591

strerror(errno));

2592

}

2593

free(fullname);

2594

}

2595

}

2596

2597

/* need to clean even if 0 because man page doesn't specify */

2598

free(direntries);

2599

if(numentries == -1){

2600

perror_plus("scandir");

2601

}

2602

ret = rmdir(tempdir);

2603

if(ret == -1 and errno != ENOENT){

2604

perror_plus("rmdir");

2605

}

3246

clean_dir_at(-1, tempdir, 0);

2606

3247

}

2607

3248

2608

3249

if(quit_now){