/mandos/release : revision 237.7.500

9

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

10

*

11

* Everything else is

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13

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*

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* 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

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

19

*

20

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

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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.

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*

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

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

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* 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

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

*/

260

330

__attribute__((nonnull, warn_unused_result))

261

static bool init_gpgme(const char *seckey, const char *pubkey,

262

const char *tempdir, mandos_context *mc){

331

static bool init_gpgme(const char * const seckey,

332

const char * const pubkey,

333

const char * const tempdir,

334

mandos_context *mc){

263

335

gpgme_error_t rc;

264

336

gpgme_engine_info_t engine_info;

265

337

266

338

/*

267

339

* Helper function to insert pub and seckey to the engine keyring.

268

340

*/

269

bool import_key(const char *filename){

341

bool import_key(const char * const filename){

270

342

int ret;

271

343

int fd;

272

344

gpgme_data_t pgp_data;

277

349

return false;

278

350

}

279

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

280

402

rc = gpgme_data_new_from_fd(&pgp_data, fd);

281

403

if(rc != GPG_ERR_NO_ERROR){

282

404

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

290

412

gpgme_strsource(rc), gpgme_strerror(rc));

291

413

return false;

292

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

}

293

490

294

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

491

ret = close(fd);

295

492

if(ret == -1){

296

493

perror_plus("close");

297

494

}

336

533

/* Create new GPGME "context" */

337

534

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

338

535

if(rc != GPG_ERR_NO_ERROR){

339

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

340

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

341

gpgme_strerror(rc));

536

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

537

gpgme_strsource(rc), gpgme_strerror(rc));

342

538

return false;

343

539

}

344

540

380

576

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

381

577

rc = gpgme_data_new(&dh_plain);

382

578

if(rc != GPG_ERR_NO_ERROR){

383

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

384

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

579

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

385

580

gpgme_strsource(rc), gpgme_strerror(rc));

386

581

gpgme_data_release(dh_crypto);

387

582

return -1;

400

595

if(result == NULL){

401

596

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

402

597

} else {

403

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

404

result->unsupported_algorithm);

405

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

406

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");

407

604

if(result->file_name != NULL){

408

605

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

409

606

}

410

gpgme_recipient_t recipient;

411

recipient = result->recipients;

412

while(recipient != NULL){

607

608

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

609

r = r->next){

413

610

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

414

gpgme_pubkey_algo_name

415

(recipient->pubkey_algo));

416

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);

417

613

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

418

recipient->status == GPG_ERR_NO_SECKEY

419

? "No" : "Yes");

420

recipient = recipient->next;

614

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

421

615

}

422

616

}

423

617

}

479

673

return plaintext_length;

480

674

}

481

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

482

683

__attribute__((warn_unused_result))

483

684

static const char *safer_gnutls_strerror(int value){

484

685

const char *ret = gnutls_strerror(value);

485

if(ret == NULL)

486

ret = "(unknown)";

487

return ret;

686

return safe_string(ret);

488

687

}

489

688

490

689

/* GnuTLS log function callback */

494

693

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

495

694

}

496

695

497

__attribute__((nonnull, warn_unused_result))

696

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

498

697

static int init_gnutls_global(const char *pubkeyfilename,

499

698

const char *seckeyfilename,

699

const char *dhparamsfilename,

500

700

mandos_context *mc){

501

701

int ret;

702

unsigned int uret;

502

703

503

704

if(debug){

504

705

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

505

706

}

506

707

507

ret = gnutls_global_init();

508

if(ret != GNUTLS_E_SUCCESS){

509

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

510

safer_gnutls_strerror(ret));

511

return -1;

512

}

513

514

708

if(debug){

515

709

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

516

710

* - GnuTLS manual

524

718

if(ret != GNUTLS_E_SUCCESS){

525

719

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

526

720

safer_gnutls_strerror(ret));

527

gnutls_global_deinit();

528

721

return -1;

529

722

}

530

723

555

748

safer_gnutls_strerror(ret));

556

749

goto globalfail;

557

750

}

558

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

559

if(ret != GNUTLS_E_SUCCESS){

560

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

561

safer_gnutls_strerror(ret));

562

goto globalfail;

563

}

564

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

}

565

928

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

566

929

567

930

return 0;

569

932

globalfail:

570

933

571

934

gnutls_certificate_free_credentials(mc->cred);

572

gnutls_global_deinit();

573

935

gnutls_dh_params_deinit(mc->dh_params);

574

936

return -1;

575

937

}

627

989

/* ignore client certificate if any. */

628

990

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

629

991

630

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

631

632

992

return 0;

633

993

}

634

994

636

996

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

637

997

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

638

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

639

1165

/* Called when a Mandos server is found */

640

1166

__attribute__((nonnull, warn_unused_result))

641

1167

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

652

1178

int retval = -1;

653

1179

gnutls_session_t session;

654

1180

int pf; /* Protocol family */

1181

bool route_added = false;

655

1182

656

1183

errno = 0;

657

1184

679

1206

bool match = false;

680

1207

{

681

1208

char *interface = NULL;

682

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

683

interface))){

1209

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

1210

mc->interfaces_size,

1211

interface))){

684

1212

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

685

1213

match = true;

686

1214

break;

715

1243

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

716

1244

}

717

1245

718

tcp_sd = socket(pf, SOCK_STREAM, 0);

1246

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

719

1247

if(tcp_sd < 0){

720

1248

int e = errno;

721

1249

perror_plus("socket");

728

1256

goto mandos_end;

729

1257

}

730

1258

731

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

732

1259

if(af == AF_INET6){

733

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

734

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);

735

1263

} else { /* IPv4 */

736

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

737

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);

738

1267

}

739

1268

if(ret < 0 ){

740

1269

int e = errno;

810

1339

goto mandos_end;

811

1340

}

812

1341

813

if(af == AF_INET6){

814

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

815

sizeof(struct sockaddr_in6));

816

} else {

817

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

818

sizeof(struct sockaddr_in));

819

}

820

if(ret < 0){

821

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

822

int e = errno;

823

perror_plus("connect");

824

errno = e;

825

}

826

goto mandos_end;

827

}

828

829

if(quit_now){

830

errno = EINTR;

831

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;

832

1397

}

833

1398

834

1399

const char *out = mandos_protocol_version;

988

1553

&decrypted_buffer, mc);

989

1554

if(decrypted_buffer_size >= 0){

990

1555

1556

clearerr(stdout);

991

1557

written = 0;

992

1558

while(written < (size_t) decrypted_buffer_size){

993

1559

if(quit_now){

1009

1575

}

1010

1576

written += (size_t)ret;

1011

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

}

1012

1588

retval = 0;

1013

1589

}

1014

1590

}

1017

1593

1018

1594

mandos_end:

1019

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

}

1020

1602

int e = errno;

1021

1603

free(decrypted_buffer);

1022

1604

free(buffer);

1023

1605

if(tcp_sd >= 0){

1024

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

1606

ret = close(tcp_sd);

1025

1607

}

1026

1608

if(ret == -1){

1027

1609

if(e == 0){

1039

1621

return retval;

1040

1622

}

1041

1623

1042

__attribute__((nonnull))

1043

1624

static void resolve_callback(AvahiSServiceResolver *r,

1044

1625

AvahiIfIndex interface,

1045

1626

AvahiProtocol proto,

1062

1643

timed out */

1063

1644

1064

1645

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1065

1647

return;

1066

1648

}

1067

1649

1181

1763

__attribute__((nonnull, warn_unused_result))

1182

1764

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

1183

1765

int ret;

1184

error_t ret_errno;

1766

int old_errno;

1185

1767

1186

1768

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

1187

1769

if(s < 0){

1188

ret_errno = errno;

1770

old_errno = errno;

1189

1771

perror_plus("socket");

1190

errno = ret_errno;

1772

errno = old_errno;

1191

1773

return false;

1192

1774

}

1193

strcpy(ifr->ifr_name, ifname);

1775

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

1776

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

1194

1777

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1195

1778

if(ret == -1){

1196

1779

if(debug){

1197

ret_errno = errno;

1780

old_errno = errno;

1198

1781

perror_plus("ioctl SIOCGIFFLAGS");

1199

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;

1200

1788

}

1201

1789

return false;

1202

1790

}

1791

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

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1203

1796

return true;

1204

1797

}

1205

1798

1333

1926

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

1334

1927

"abcdefghijklmnopqrstuvwxyz"

1335

1928

"0123456789"

1336

"_-");

1929

"_.-");

1337

1930

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

1338

1931

/* Contains non-allowed characters */

1339

1932

if(debug){

1343

1936

return 0;

1344

1937

}

1345

1938

1346

char *fullname = NULL;

1347

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

1348

if(ret < 0){

1349

perror_plus("asprintf");

1350

return 0;

1351

}

1352

1353

ret = stat(fullname, &st);

1939

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

1354

1940

if(ret == -1){

1355

1941

if(debug){

1356

1942

perror_plus("Could not stat hook");

1454

2040

}

1455

2041

}

1456

2042

1457

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

1458

__attribute__((warn_unused_result))

1459

error_t raise_privileges(void){

1460

error_t old_errno = errno;

1461

error_t ret_errno = 0;

1462

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

1463

ret_errno = errno;

1464

perror_plus("seteuid");

1465

}

1466

errno = old_errno;

1467

return ret_errno;

1468

}

1469

1470

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

1471

__attribute__((warn_unused_result))

1472

error_t raise_privileges_permanently(void){

1473

error_t old_errno = errno;

1474

error_t ret_errno = raise_privileges();

1475

if(ret_errno != 0){

1476

errno = old_errno;

1477

return ret_errno;

1478

}

1479

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

1480

ret_errno = errno;

1481

perror_plus("seteuid");

1482

}

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

1487

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

1488

__attribute__((warn_unused_result))

1489

error_t lower_privileges(void){

1490

error_t old_errno = errno;

1491

error_t ret_errno = 0;

1492

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

1493

ret_errno = errno;

1494

perror_plus("seteuid");

1495

}

1496

errno = old_errno;

1497

return ret_errno;

1498

}

1499

1500

/* Lower privileges permanently */

1501

__attribute__((warn_unused_result))

1502

error_t lower_privileges_permanently(void){

1503

error_t old_errno = errno;

1504

error_t ret_errno = 0;

1505

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

1506

ret_errno = errno;

1507

perror_plus("setuid");

1508

}

1509

errno = old_errno;

1510

return ret_errno;

1511

}

1512

1513

2043

__attribute__((nonnull))

1514

2044

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

1515

2045

const float delay){

1516

struct dirent **direntries;

1517

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

1518

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);

1519

2069

if(numhooks == -1){

1520

if(errno == ENOENT){

1521

if(debug){

1522

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

1523

" found\n", hookdir);

1524

}

1525

} else {

1526

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);

1527

2081

}

1528

} else {

1529

struct dirent *direntry;

1530

int ret;

1531

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

1532

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

1533

direntry = direntries[i];

1534

char *fullname = NULL;

1535

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

1536

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){

1537

2128

perror_plus("asprintf");

1538

continue;

1539

}

1540

if(debug){

1541

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

1542

direntry->d_name);

1543

}

1544

pid_t hook_pid = fork();

1545

if(hook_pid == 0){

1546

/* Child */

1547

/* Raise privileges */

1548

if(raise_privileges_permanently() != 0){

1549

perror_plus("Failed to raise privileges");

1550

_exit(EX_NOPERM);

1551

}

1552

/* Set group */

1553

errno = 0;

1554

ret = setgid(0);

1555

if(ret == -1){

1556

perror_plus("setgid");

1557

_exit(EX_NOPERM);

1558

}

1559

/* Reset supplementary groups */

1560

errno = 0;

1561

ret = setgroups(0, NULL);

1562

if(ret == -1){

1563

perror_plus("setgroups");

1564

_exit(EX_NOPERM);

1565

}

1566

ret = dup2(devnull, STDIN_FILENO);

1567

if(ret == -1){

1568

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

1569

_exit(EX_OSERR);

1570

}

1571

ret = close(devnull);

1572

if(ret == -1){

1573

perror_plus("close");

1574

_exit(EX_OSERR);

1575

}

1576

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1577

if(ret == -1){

1578

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

1579

_exit(EX_OSERR);

1580

}

1581

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

1582

if(ret == -1){

1583

perror_plus("setenv");

1584

_exit(EX_OSERR);

1585

}

1586

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

1587

if(ret == -1){

1588

perror_plus("setenv");

1589

_exit(EX_OSERR);

1590

}

1591

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

1592

if(ret == -1){

1593

perror_plus("setenv");

1594

_exit(EX_OSERR);

1595

}

1596

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

1597

if(ret == -1){

1598

perror_plus("setenv");

1599

_exit(EX_OSERR);

1600

}

1601

char *delaystring;

1602

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

1603

if(ret == -1){

1604

perror_plus("asprintf");

1605

_exit(EX_OSERR);

1606

}

1607

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

1608

if(ret == -1){

1609

free(delaystring);

1610

perror_plus("setenv");

1611

_exit(EX_OSERR);

1612

}

2129

_exit(EX_OSERR);

2130

}

2131

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

2132

if(ret == -1){

1613

2133

free(delaystring);

1614

if(connect_to != NULL){

1615

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

1616

if(ret == -1){

1617

perror_plus("setenv");

1618

_exit(EX_OSERR);

1619

}

1620

}

1621

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

1622

perror_plus("execl");

1623

_exit(EXIT_FAILURE);

1624

}

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;

1625

2202

} else {

1626

int status;

1627

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

1628

perror_plus("waitpid");

1629

free(fullname);

1630

continue;

1631

}

1632

if(WIFEXITED(status)){

1633

if(WEXITSTATUS(status) != 0){

1634

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

1635

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

1636

WEXITSTATUS(status));

1637

free(fullname);

1638

continue;

1639

}

1640

} else if(WIFSIGNALED(status)){

1641

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

1642

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

1643

WTERMSIG(status));

1644

free(fullname);

1645

continue;

1646

} else {

1647

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

1648

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

1649

free(fullname);

1650

continue;

1651

}

1652

}

1653

free(fullname);

1654

if(debug){

1655

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

1656

direntry->d_name);

1657

}

1658

}

1659

close(devnull);

1660

}

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);

1661

2222

}

1662

2223

1663

2224

__attribute__((nonnull, warn_unused_result))

1664

error_t bring_up_interface(const char *const interface,

1665

const float delay){

1666

error_t old_errno = errno;

2225

int bring_up_interface(const char *const interface,

2226

const float delay){

2227

int old_errno = errno;

1667

2228

int ret;

1668

2229

struct ifreq network;

1669

2230

unsigned int if_index = if_nametoindex(interface);

1679

2240

}

1680

2241

1681

2242

if(not interface_is_up(interface)){

1682

error_t ret_errno = 0, ioctl_errno = 0;

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

1683

2245

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

1684

2246

ret_errno = errno;

1685

2247

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

1698

2260

}

1699

2261

1700

2262

if(quit_now){

1701

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

2263

ret = close(sd);

1702

2264

if(ret == -1){

1703

2265

perror_plus("close");

1704

2266

}

1713

2275

1714

2276

/* Raise privileges */

1715

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;

1716

2285

bool restore_loglevel = false;

1717

if(ret_errno != 0){

1718

perror_plus("Failed to raise privileges");

1719

}

1720

#ifdef __linux__

1721

int ret_linux;

1722

2286

if(ret_errno == 0){

1723

2287

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1724

2288

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

1752

2316

}

1753

2317

1754

2318

/* Close the socket */

1755

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

2319

ret = close(sd);

1756

2320

if(ret == -1){

1757

2321

perror_plus("close");

1758

2322

}

1770

2334

1771

2335

/* Sleep checking until interface is running.

1772

2336

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

1773

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

2337

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

1774

2338

if(interface_is_running(interface)){

1775

2339

break;

1776

2340

}

1786

2350

}

1787

2351

1788

2352

__attribute__((nonnull, warn_unused_result))

1789

error_t take_down_interface(const char *const interface){

1790

error_t old_errno = errno;

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

1791

2355

struct ifreq network;

1792

2356

unsigned int if_index = if_nametoindex(interface);

1793

2357

if(if_index == 0){

1796

2360

return ENXIO;

1797

2361

}

1798

2362

if(interface_is_up(interface)){

1799

error_t ret_errno = 0, ioctl_errno = 0;

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

1800

2365

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

1801

2366

ret_errno = errno;

1802

2367

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

1822

2387

/* Raise privileges */

1823

2388

ret_errno = raise_privileges();

1824

2389

if(ret_errno != 0){

2390

errno = ret_errno;

1825

2391

perror_plus("Failed to raise privileges");

1826

2392

}

2393

1827

2394

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

1828

2395

ioctl_errno = errno;

1829

2396

1838

2405

}

1839

2406

1840

2407

/* Close the socket */

1841

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

2408

int ret = close(sd);

1842

2409

if(ret == -1){

1843

2410

perror_plus("close");

1844

2411

}

1859

2426

}

1860

2427

1861

2428

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

1862

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

1863

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

1864

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

1865

.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 };

1866

2434

AvahiSServiceBrowser *sb = NULL;

1867

2435

error_t ret_errno;

1868

2436

int ret;

1871

2439

int exitcode = EXIT_SUCCESS;

1872

2440

char *interfaces_to_take_down = NULL;

1873

2441

size_t interfaces_to_take_down_size = 0;

1874

char tempdir[] = "/tmp/mandosXXXXXX";

1875

bool tempdir_created = false;

2442

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2443

char old_tempdir[] = "/tmp/mandosXXXXXX";

2444

char *tempdir = NULL;

1876

2445

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1877

2446

const char *seckey = PATHDIR "/" SECKEY;

1878

2447

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

1879

2449

char *interfaces_hooks = NULL;

1880

2450

1881

2451

bool gnutls_initialized = false;

1934

2504

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

1935

2505

" Diffie-Hellman key exchange",

1936

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 },

1937

2512

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

1938

2513

.arg = "STRING",

1939

2514

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

1994

2569

}

1995

2570

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

1996

2571

break;

2572

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

2573

dh_params_file = arg;

2574

break;

1997

2575

case 130: /* --priority */

1998

2576

mc.priority = arg;

1999

2577

break;

2039

2617

.args_doc = "",

2040

2618

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

2041

2619

" passwords from a Mandos server" };

2042

ret = argp_parse(&argp, argc, argv,

2043

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2044

switch(ret){

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

2045

2623

case 0:

2046

2624

break;

2047

2625

case ENOMEM:

2048

2626

default:

2049

errno = ret;

2627

errno = ret_errno;

2050

2628

perror_plus("argp_parse");

2051

2629

exitcode = EX_OSERR;

2052

2630

goto end;

2055

2633

goto end;

2056

2634

}

2057

2635

}

2058

2636

2059

2637

{

2060

2638

/* Work around Debian bug #633582:

2061

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

2639

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

2062

2640

2063

2641

/* Re-raise privileges */

2064

ret_errno = raise_privileges();

2065

if(ret_errno != 0){

2066

errno = ret_errno;

2642

ret = raise_privileges();

2643

if(ret != 0){

2644

errno = ret;

2067

2645

perror_plus("Failed to raise privileges");

2068

2646

} else {

2069

2647

struct stat st;

2085

2663

}

2086

2664

}

2087

2665

}

2088

TEMP_FAILURE_RETRY(close(seckey_fd));

2666

close(seckey_fd);

2089

2667

}

2090

2668

}

2091

2669

2092

2670

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

2093

2671

int pubkey_fd = open(pubkey, O_RDONLY);

2094

2672

if(pubkey_fd == -1){

2106

2684

}

2107

2685

}

2108

2686

}

2109

TEMP_FAILURE_RETRY(close(pubkey_fd));

2110

}

2111

}

2112

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

2113

2713

/* Lower privileges */

2114

ret_errno = lower_privileges();

2115

if(ret_errno != 0){

2116

errno = ret_errno;

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2117

2717

perror_plus("Failed to lower privileges");

2118

2718

}

2119

2719

}

2232

2832

2233

2833

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

2234

2834

if(mc.interfaces == NULL){

2235

struct dirent **direntries;

2835

struct dirent **direntries = NULL;

2236

2836

/* Look for any good interfaces */

2237

2837

ret = scandir(sys_class_net, &direntries, good_interface,

2238

2838

alphasort);

2244

2844

if(ret_errno != 0){

2245

2845

errno = ret_errno;

2246

2846

perror_plus("argz_add");

2847

free(direntries[i]);

2247

2848

continue;

2248

2849

}

2249

2850

if(debug){

2250

2851

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

2251

2852

direntries[i]->d_name);

2252

2853

}

2854

free(direntries[i]);

2253

2855

}

2254

2856

free(direntries);

2255

2857

} else {

2256

free(direntries);

2858

if(ret == 0){

2859

free(direntries);

2860

}

2257

2861

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

2258

2862

exitcode = EXIT_FAILURE;

2259

2863

goto end;

2285

2889

errno = bring_up_interface(interface, delay);

2286

2890

if(not interface_was_up){

2287

2891

if(errno != 0){

2288

perror_plus("Failed to bring up interface");

2892

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

2893

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

2289

2894

} else {

2290

2895

errno = argz_add(&interfaces_to_take_down,

2291

2896

&interfaces_to_take_down_size,

2314

2919

goto end;

2315

2920

}

2316

2921

2317

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

2922

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

2318

2923

if(ret == -1){

2319

2924

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

2320

2925

exitcode = EX_UNAVAILABLE;

2327

2932

goto end;

2328

2933

}

2329

2934

2330

if(mkdtemp(tempdir) == NULL){

2935

/* Try /run/tmp before /tmp */

2936

tempdir = mkdtemp(run_tempdir);

2937

if(tempdir == NULL and errno == ENOENT){

2938

if(debug){

2939

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2940

run_tempdir, old_tempdir);

2941

}

2942

tempdir = mkdtemp(old_tempdir);

2943

}

2944

if(tempdir == NULL){

2331

2945

perror_plus("mkdtemp");

2332

2946

goto end;

2333

2947

}

2334

tempdir_created = true;

2335

2948

2336

2949

if(quit_now){

2337

2950

goto end;

2434

3047

2435

3048

/* Allocate a new server */

2436

3049

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2437

&config, NULL, NULL, &ret_errno);

3050

&config, NULL, NULL, &ret);

2438

3051

2439

3052

/* Free the Avahi configuration data */

2440

3053

avahi_server_config_free(&config);

2443

3056

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

2444

3057

if(mc.server == NULL){

2445

3058

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

2446

avahi_strerror(ret_errno));

3059

avahi_strerror(ret));

2447

3060

exitcode = EX_UNAVAILABLE;

2448

3061

goto end;

2449

3062

}

2473

3086

if(debug){

2474

3087

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

2475

3088

}

2476

3089

2477

3090

ret = avahi_loop_with_timeout(simple_poll,

2478

3091

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

2479

3092

if(debug){

2484

3097

end:

2485

3098

2486

3099

if(debug){

2487

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

}

2488

3107

}

2489

3108

2490

3109

/* Cleanup things */

2501

3120

2502

3121

if(gnutls_initialized){

2503

3122

gnutls_certificate_free_credentials(mc.cred);

2504

gnutls_global_deinit();

2505

3123

gnutls_dh_params_deinit(mc.dh_params);

2506

3124

}

2507

3125

2515

3133

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

2516

3134

while(mc.current_server != NULL){

2517

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

2518

3144

free(mc.current_server);

2519

3145

mc.current_server = next;

2520

3146

}

2522

3148

2523

3149

/* Re-raise privileges */

2524

3150

{

2525

ret_errno = raise_privileges();

2526

if(ret_errno != 0){

3151

ret = raise_privileges();

3152

if(ret != 0){

3153

errno = ret;

2527

3154

perror_plus("Failed to raise privileges");

2528

3155

} else {

2529

3156

2534

3161

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

2535

3162

{

2536

3163

char *interface = NULL;

2537

while((interface=argz_next(interfaces_to_take_down,

2538

interfaces_to_take_down_size,

2539

interface))){

2540

ret_errno = take_down_interface(interface);

2541

if(ret_errno != 0){

2542

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;

2543

3170

perror_plus("Failed to take down interface");

2544

3171

}

2545

3172

}

2549

3176

}

2550

3177

}

2551

3178

}

2552

ret_errno = lower_privileges_permanently();

2553

if(ret_errno != 0){

3179

3180

ret = lower_privileges_permanently();

3181

if(ret != 0){

3182

errno = ret;

2554

3183

perror_plus("Failed to lower privileges permanently");

2555

3184

}

2556

3185

}

2558

3187

free(interfaces_to_take_down);

2559

3188

free(interfaces_hooks);

2560

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

2561

3244

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

2562

if(tempdir_created){

2563

struct dirent **direntries = NULL;

2564

struct dirent *direntry = NULL;

2565

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

2566

alphasort);

2567

if(numentries > 0){

2568

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

2569

direntry = direntries[i];

2570

char *fullname = NULL;

2571

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

2572

direntry->d_name);

2573

if(ret < 0){

2574

perror_plus("asprintf");

2575

continue;

2576

}

2577

ret = remove(fullname);

2578

if(ret == -1){

2579

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

2580

strerror(errno));

2581

}

2582

free(fullname);

2583

}

2584

}

2585

2586

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

2587

free(direntries);

2588

if(numentries == -1){

2589

perror_plus("scandir");

2590

}

2591

ret = rmdir(tempdir);

2592

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

2593

perror_plus("rmdir");

2594

}

3245

if(tempdir != NULL){

3246

clean_dir_at(-1, tempdir, 0);

2595

3247

}

2596

3248

2597

3249

if(quit_now){