/mandos/release : revision 237.7.495

9

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

10

*

11

* Everything else is

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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.

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*

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

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13

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*

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

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* (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

*

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27

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

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* 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/>.

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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 */

292

310

gpgme_strsource(rc), gpgme_strerror(rc));

293

311

return false;

294

312

}

313

{

314

gpgme_import_result_t import_result

315

= gpgme_op_import_result(mc->ctx);

316

if((import_result->imported < 1

317

or import_result->not_imported > 0)

318

and import_result->unchanged == 0){

319

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

320

fprintf_plus(stderr,

321

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

322

import_result->considered);

323

fprintf_plus(stderr,

324

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

325

import_result->no_user_id);

326

fprintf_plus(stderr,

327

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

328

import_result->imported);

329

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

330

import_result->imported_rsa);

331

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

332

import_result->unchanged);

333

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

334

import_result->new_user_ids);

335

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

336

import_result->new_sub_keys);

337

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

338

import_result->new_signatures);

339

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

340

import_result->new_revocations);

341

fprintf_plus(stderr,

342

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

343

import_result->secret_read);

344

fprintf_plus(stderr,

345

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

346

import_result->secret_imported);

347

fprintf_plus(stderr,

348

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

349

import_result->secret_unchanged);

350

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

351

import_result->not_imported);

352

for(gpgme_import_status_t import_status

353

= import_result->imports;

354

import_status != NULL;

355

import_status = import_status->next){

356

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

357

import_status->fpr);

358

if(import_status->result != GPG_ERR_NO_ERROR){

359

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

360

gpgme_strsource(import_status->result),

361

gpgme_strerror(import_status->result));

362

}

363

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

364

fprintf_plus(stderr,

365

import_status->status & GPGME_IMPORT_NEW

366

? "The key was new.\n"

367

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

368

fprintf_plus(stderr,

369

import_status->status & GPGME_IMPORT_UID

370

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

371

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

372

fprintf_plus(stderr,

373

import_status->status & GPGME_IMPORT_SIG

374

? "The key contained new signatures.\n"

375

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

376

fprintf_plus(stderr,

377

import_status->status & GPGME_IMPORT_SUBKEY

378

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

379

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

380

fprintf_plus(stderr,

381

import_status->status & GPGME_IMPORT_SECRET

382

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

383

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

384

}

385

return false;

386

}

387

}

295

388

296

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

389

ret = close(fd);

297

390

if(ret == -1){

298

391

perror_plus("close");

299

392

}

338

431

/* Create new GPGME "context" */

339

432

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

340

433

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));

434

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

435

gpgme_strsource(rc), gpgme_strerror(rc));

344

436

return false;

345

437

}

346

438

382

474

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

383

475

rc = gpgme_data_new(&dh_plain);

384

476

if(rc != GPG_ERR_NO_ERROR){

385

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

386

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

477

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

387

478

gpgme_strsource(rc), gpgme_strerror(rc));

388

479

gpgme_data_release(dh_crypto);

389

480

return -1;

402

493

if(result == NULL){

403

494

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

404

495

} 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);

496

if(result->unsupported_algorithm != NULL) {

497

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

498

result->unsupported_algorithm);

499

}

500

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

501

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

409

502

if(result->file_name != NULL){

410

503

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

411

504

}

481

574

return plaintext_length;

482

575

}

483

576

577

__attribute__((warn_unused_result, const))

578

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

579

if(str == NULL)

580

return "(unknown)";

581

return str;

582

}

583

484

584

__attribute__((warn_unused_result))

485

585

static const char *safer_gnutls_strerror(int value){

486

586

const char *ret = gnutls_strerror(value);

487

if(ret == NULL)

488

ret = "(unknown)";

489

return ret;

587

return safe_string(ret);

490

588

}

491

589

492

590

/* GnuTLS log function callback */

496

594

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

497

595

}

498

596

499

__attribute__((nonnull, warn_unused_result))

597

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

500

598

static int init_gnutls_global(const char *pubkeyfilename,

501

599

const char *seckeyfilename,

600

const char *dhparamsfilename,

502

601

mandos_context *mc){

503

602

int ret;

603

unsigned int uret;

504

604

505

605

if(debug){

506

606

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

507

607

}

508

608

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

609

if(debug){

517

610

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

518

611

* - GnuTLS manual

526

619

if(ret != GNUTLS_E_SUCCESS){

527

620

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

528

621

safer_gnutls_strerror(ret));

529

gnutls_global_deinit();

530

622

return -1;

531

623

}

532

624

557

649

safer_gnutls_strerror(ret));

558

650

goto globalfail;

559

651

}

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

652

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

653

if(dhparamsfilename != NULL){

654

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

655

do {

656

int dhpfile = open(dhparamsfilename, O_RDONLY);

657

if(dhpfile == -1){

658

perror_plus("open");

659

dhparamsfilename = NULL;

660

break;

661

}

662

size_t params_capacity = 0;

663

while(true){

664

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

665

(size_t)params.size,

666

(size_t)params_capacity);

667

if(params_capacity == 0){

668

perror_plus("incbuffer");

669

free(params.data);

670

params.data = NULL;

671

dhparamsfilename = NULL;

672

break;

673

}

674

ssize_t bytes_read = read(dhpfile,

675

params.data + params.size,

676

BUFFER_SIZE);

677

/* EOF */

678

if(bytes_read == 0){

679

break;

680

}

681

/* check bytes_read for failure */

682

if(bytes_read < 0){

683

perror_plus("read");

684

free(params.data);

685

params.data = NULL;

686

dhparamsfilename = NULL;

687

break;

688

}

689

params.size += (unsigned int)bytes_read;

690

}

691

ret = close(dhpfile);

692

if(ret == -1){

693

perror_plus("close");

694

}

695

if(params.data == NULL){

696

dhparamsfilename = NULL;

697

}

698

if(dhparamsfilename == NULL){

699

break;

700

}

701

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

702

GNUTLS_X509_FMT_PEM);

703

if(ret != GNUTLS_E_SUCCESS){

704

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

705

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

706

safer_gnutls_strerror(ret));

707

dhparamsfilename = NULL;

708

}

709

free(params.data);

710

} while(false);

711

}

712

if(dhparamsfilename == NULL){

713

if(mc->dh_bits == 0){

714

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

715

/* Try to read the private key file */

716

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

717

do {

718

int secfile = open(seckeyfilename, O_RDONLY);

719

if(secfile == -1){

720

perror_plus("open");

721

break;

722

}

723

size_t buffer_capacity = 0;

724

while(true){

725

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

726

(size_t)buffer.size,

727

(size_t)buffer_capacity);

728

if(buffer_capacity == 0){

729

perror_plus("incbuffer");

730

free(buffer.data);

731

buffer.data = NULL;

732

break;

733

}

734

ssize_t bytes_read = read(secfile,

735

buffer.data + buffer.size,

736

BUFFER_SIZE);

737

/* EOF */

738

if(bytes_read == 0){

739

break;

740

}

741

/* check bytes_read for failure */

742

if(bytes_read < 0){

743

perror_plus("read");

744

free(buffer.data);

745

buffer.data = NULL;

746

break;

747

}

748

buffer.size += (unsigned int)bytes_read;

749

}

750

close(secfile);

751

} while(false);

752

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

753

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

754

if(buffer.data != NULL){

755

{

756

gnutls_openpgp_privkey_t privkey = NULL;

757

ret = gnutls_openpgp_privkey_init(&privkey);

758

if(ret != GNUTLS_E_SUCCESS){

759

fprintf_plus(stderr, "Error initializing OpenPGP key"

760

" structure: %s",

761

safer_gnutls_strerror(ret));

762

free(buffer.data);

763

buffer.data = NULL;

764

} else {

765

ret = gnutls_openpgp_privkey_import

766

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

767

if(ret != GNUTLS_E_SUCCESS){

768

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

769

safer_gnutls_strerror(ret));

770

privkey = NULL;

771

}

772

free(buffer.data);

773

buffer.data = NULL;

774

if(privkey != NULL){

775

/* Use private key to suggest an appropriate

776

sec_param */

777

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

778

gnutls_openpgp_privkey_deinit(privkey);

779

if(debug){

780

fprintf_plus(stderr, "This OpenPGP key implies using"

781

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

782

safe_string(gnutls_sec_param_get_name

783

(sec_param)));

784

}

785

}

786

}

787

}

788

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

789

/* Err on the side of caution */

790

sec_param = GNUTLS_SEC_PARAM_ULTRA;

791

if(debug){

792

fprintf_plus(stderr, "Falling back to security parameter"

793

" \"%s\"\n",

794

safe_string(gnutls_sec_param_get_name

795

(sec_param)));

796

}

797

}

798

}

799

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

800

if(uret != 0){

801

mc->dh_bits = uret;

802

if(debug){

803

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

804

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

805

safe_string(gnutls_sec_param_get_name

806

(sec_param)),

807

mc->dh_bits);

808

}

809

} else {

810

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

811

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

812

safe_string(gnutls_sec_param_get_name

813

(sec_param)),

814

safer_gnutls_strerror(ret));

815

goto globalfail;

816

}

817

} else if(debug){

818

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

819

mc->dh_bits);

820

}

821

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

822

if(ret != GNUTLS_E_SUCCESS){

823

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

824

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

825

safer_gnutls_strerror(ret));

826

goto globalfail;

827

}

828

}

567

829

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

568

830

569

831

return 0;

571

833

globalfail:

572

834

573

835

gnutls_certificate_free_credentials(mc->cred);

574

gnutls_global_deinit();

575

836

gnutls_dh_params_deinit(mc->dh_params);

576

837

return -1;

577

838

}

629

890

/* ignore client certificate if any. */

630

891

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

631

892

632

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

633

634

893

return 0;

635

894

}

636

895

638

897

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

639

898

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

640

899

900

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

901

__attribute__((warn_unused_result))

902

int raise_privileges(void){

903

int old_errno = errno;

904

int ret = 0;

905

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

906

ret = errno;

907

}

908

errno = old_errno;

909

return ret;

910

}

911

912

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

913

__attribute__((warn_unused_result))

914

int raise_privileges_permanently(void){

915

int old_errno = errno;

916

int ret = raise_privileges();

917

if(ret != 0){

918

errno = old_errno;

919

return ret;

920

}

921

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

922

ret = errno;

923

}

924

errno = old_errno;

925

return ret;

926

}

927

928

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

929

__attribute__((warn_unused_result))

930

int lower_privileges(void){

931

int old_errno = errno;

932

int ret = 0;

933

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

934

ret = errno;

935

}

936

errno = old_errno;

937

return ret;

938

}

939

940

/* Lower privileges permanently */

941

__attribute__((warn_unused_result))

942

int lower_privileges_permanently(void){

943

int old_errno = errno;

944

int ret = 0;

945

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

946

ret = errno;

947

}

948

errno = old_errno;

949

return ret;

950

}

951

952

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

953

__attribute__((nonnull, warn_unused_result))

954

static bool add_delete_local_route(const bool add,

955

const char *address,

956

AvahiIfIndex if_index){

957

int ret;

958

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

959

char add_arg[] = "add";

960

char delete_arg[] = "delete";

961

char debug_flag[] = "--debug";

962

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

963

if(pluginhelperdir == NULL){

964

if(debug){

965

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

966

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

967

}

968

return false;

969

}

970

971

char interface[IF_NAMESIZE];

972

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

973

perror_plus("if_indextoname");

974

return false;

975

}

976

977

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

978

if(devnull == -1){

979

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

980

return false;

981

}

982

pid_t pid = fork();

983

if(pid == 0){

984

/* Child */

985

/* Raise privileges */

986

errno = raise_privileges_permanently();

987

if(errno != 0){

988

perror_plus("Failed to raise privileges");

989

/* _exit(EX_NOPERM); */

990

} else {

991

/* Set group */

992

errno = 0;

993

ret = setgid(0);

994

if(ret == -1){

995

perror_plus("setgid");

996

_exit(EX_NOPERM);

997

}

998

/* Reset supplementary groups */

999

errno = 0;

1000

ret = setgroups(0, NULL);

1001

if(ret == -1){

1002

perror_plus("setgroups");

1003

_exit(EX_NOPERM);

1004

}

1005

}

1006

ret = dup2(devnull, STDIN_FILENO);

1007

if(ret == -1){

1008

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

1009

_exit(EX_OSERR);

1010

}

1011

ret = close(devnull);

1012

if(ret == -1){

1013

perror_plus("close");

1014

_exit(EX_OSERR);

1015

}

1016

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1017

if(ret == -1){

1018

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

1019

_exit(EX_OSERR);

1020

}

1021

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

1022

O_RDONLY

1023

| O_DIRECTORY

1024

| O_PATH

1025

| O_CLOEXEC));

1026

if(helperdir_fd == -1){

1027

perror_plus("open");

1028

_exit(EX_UNAVAILABLE);

1029

}

1030

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

1031

helper, O_RDONLY));

1032

if(helper_fd == -1){

1033

perror_plus("openat");

1034

close(helperdir_fd);

1035

_exit(EX_UNAVAILABLE);

1036

}

1037

close(helperdir_fd);

1038

#ifdef __GNUC__

1039

#pragma GCC diagnostic push

1040

#pragma GCC diagnostic ignored "-Wcast-qual"

1041

#endif

1042

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

1043

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

1044

interface, debug ? debug_flag : NULL, NULL },

1045

environ) == -1){

1046

#ifdef __GNUC__

1047

#pragma GCC diagnostic pop

1048

#endif

1049

perror_plus("fexecve");

1050

_exit(EXIT_FAILURE);

1051

}

1052

}

1053

if(pid == -1){

1054

perror_plus("fork");

1055

return false;

1056

}

1057

int status;

1058

pid_t pret = -1;

1059

errno = 0;

1060

do {

1061

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

1062

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

1063

int errno_raising = 0;

1064

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

1065

errno_raising = errno;

1066

perror_plus("Failed to raise privileges in order to"

1067

" kill helper program");

1068

}

1069

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

1070

perror_plus("kill");

1071

}

1072

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

1073

perror_plus("Failed to lower privileges after killing"

1074

" helper program");

1075

}

1076

return false;

1077

}

1078

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

1079

if(pret == -1){

1080

perror_plus("waitpid");

1081

return false;

1082

}

1083

if(WIFEXITED(status)){

1084

if(WEXITSTATUS(status) != 0){

1085

fprintf_plus(stderr, "Error: iprouteadddel exited"

1086

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

1087

return false;

1088

}

1089

return true;

1090

}

1091

if(WIFSIGNALED(status)){

1092

fprintf_plus(stderr, "Error: iprouteadddel died by"

1093

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

1094

return false;

1095

}

1096

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

1097

return false;

1098

}

1099

1100

__attribute__((nonnull, warn_unused_result))

1101

static bool add_local_route(const char *address,

1102

AvahiIfIndex if_index){

1103

if(debug){

1104

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

1105

}

1106

return add_delete_local_route(true, address, if_index);

1107

}

1108

1109

__attribute__((nonnull, warn_unused_result))

1110

static bool delete_local_route(const char *address,

1111

AvahiIfIndex if_index){

1112

if(debug){

1113

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

1114

}

1115

return add_delete_local_route(false, address, if_index);

1116

}

1117

641

1118

/* Called when a Mandos server is found */

642

1119

__attribute__((nonnull, warn_unused_result))

643

1120

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

654

1131

int retval = -1;

655

1132

gnutls_session_t session;

656

1133

int pf; /* Protocol family */

1134

bool route_added = false;

657

1135

658

1136

errno = 0;

659

1137

681

1159

bool match = false;

682

1160

{

683

1161

char *interface = NULL;

684

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

685

interface))){

1162

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

1163

mc->interfaces_size,

1164

interface))){

686

1165

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

687

1166

match = true;

688

1167

break;

717

1196

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

718

1197

}

719

1198

720

tcp_sd = socket(pf, SOCK_STREAM, 0);

1199

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

721

1200

if(tcp_sd < 0){

722

1201

int e = errno;

723

1202

perror_plus("socket");

730

1209

goto mandos_end;

731

1210

}

732

1211

733

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

734

1212

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);

1213

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

1214

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

1215

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

737

1216

} 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);

1217

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

1218

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

1219

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

740

1220

}

741

1221

if(ret < 0 ){

742

1222

int e = errno;

812

1292

goto mandos_end;

813

1293

}

814

1294

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;

1295

while(true){

1296

if(af == AF_INET6){

1297

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

1298

sizeof(struct sockaddr_in6));

1299

} else {

1300

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

1301

sizeof(struct sockaddr_in));

1302

}

1303

if(ret < 0){

1304

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

1305

and if_index != AVAHI_IF_UNSPEC

1306

and connect_to == NULL

1307

and not route_added and

1308

((af == AF_INET6 and not

1309

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1310

&to)->sin6_addr)))

1311

or (af == AF_INET and

1312

/* Not a a IPv4LL address */

1313

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

1314

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

1315

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

1316

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

1317

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

1318

connect to a Mandos server announced by Avahi on a server

1319

host with a global address. Work around this by retrying

1320

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

1321

1322

Avahi bug reference:

1323

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

1324

https://bugs.debian.org/587961

1325

*/

1326

if(debug){

1327

fprintf_plus(stderr, "Mandos server unreachable, trying"

1328

" direct route\n");

1329

}

1330

int e = errno;

1331

route_added = add_local_route(ip, if_index);

1332

if(route_added){

1333

continue;

1334

}

1335

errno = e;

1336

}

1337

if(errno != ECONNREFUSED or debug){

1338

int e = errno;

1339

perror_plus("connect");

1340

errno = e;

1341

}

1342

goto mandos_end;

1343

}

1344

1345

if(quit_now){

1346

errno = EINTR;

1347

goto mandos_end;

1348

}

1349

break;

834

1350

}

835

1351

836

1352

const char *out = mandos_protocol_version;

990

1506

&decrypted_buffer, mc);

991

1507

if(decrypted_buffer_size >= 0){

992

1508

1509

clearerr(stdout);

993

1510

written = 0;

994

1511

while(written < (size_t) decrypted_buffer_size){

995

1512

if(quit_now){

1011

1528

}

1012

1529

written += (size_t)ret;

1013

1530

}

1531

ret = fflush(stdout);

1532

if(ret != 0){

1533

int e = errno;

1534

if(debug){

1535

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

1536

strerror(errno));

1537

}

1538

errno = e;

1539

goto mandos_end;

1540

}

1014

1541

retval = 0;

1015

1542

}

1016

1543

}

1019

1546

1020

1547

mandos_end:

1021

1548

{

1549

if(route_added){

1550

if(not delete_local_route(ip, if_index)){

1551

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

1552

" interface %d", ip, if_index);

1553

}

1554

}

1022

1555

int e = errno;

1023

1556

free(decrypted_buffer);

1024

1557

free(buffer);

1025

1558

if(tcp_sd >= 0){

1026

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

1559

ret = close(tcp_sd);

1027

1560

}

1028

1561

if(ret == -1){

1029

1562

if(e == 0){

1041

1574

return retval;

1042

1575

}

1043

1576

1044

__attribute__((nonnull))

1045

1577

static void resolve_callback(AvahiSServiceResolver *r,

1046

1578

AvahiIfIndex interface,

1047

1579

AvahiProtocol proto,

1064

1596

timed out */

1065

1597

1066

1598

if(quit_now){

1599

avahi_s_service_resolver_free(r);

1067

1600

return;

1068

1601

}

1069

1602

1183

1716

__attribute__((nonnull, warn_unused_result))

1184

1717

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

1185

1718

int ret;

1186

error_t ret_errno;

1719

int old_errno;

1187

1720

1188

1721

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

1189

1722

if(s < 0){

1190

ret_errno = errno;

1723

old_errno = errno;

1191

1724

perror_plus("socket");

1192

errno = ret_errno;

1725

errno = old_errno;

1193

1726

return false;

1194

1727

}

1195

strcpy(ifr->ifr_name, ifname);

1728

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

1729

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

1196

1730

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1197

1731

if(ret == -1){

1198

1732

if(debug){

1199

ret_errno = errno;

1733

old_errno = errno;

1200

1734

perror_plus("ioctl SIOCGIFFLAGS");

1201

errno = ret_errno;

1735

errno = old_errno;

1736

}

1737

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

1738

old_errno = errno;

1739

perror_plus("close");

1740

errno = old_errno;

1202

1741

}

1203

1742

return false;

1204

1743

}

1744

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

1745

old_errno = errno;

1746

perror_plus("close");

1747

errno = old_errno;

1748

}

1205

1749

return true;

1206

1750

}

1207

1751

1335

1879

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

1336

1880

"abcdefghijklmnopqrstuvwxyz"

1337

1881

"0123456789"

1338

"_-");

1882

"_.-");

1339

1883

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

1340

1884

/* Contains non-allowed characters */

1341

1885

if(debug){

1345

1889

return 0;

1346

1890

}

1347

1891

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);

1892

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

1356

1893

if(ret == -1){

1357

1894

if(debug){

1358

1895

perror_plus("Could not stat hook");

1456

1993

}

1457

1994

}

1458

1995

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

1996

__attribute__((nonnull))

1516

1997

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

1517

1998

const float delay){

1518

struct dirent **direntries;

1519

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

1520

alphasort);

1999

struct dirent **direntries = NULL;

2000

if(hookdir_fd == -1){

2001

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2002

| O_CLOEXEC);

2003

if(hookdir_fd == -1){

2004

if(errno == ENOENT){

2005

if(debug){

2006

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

2007

" found\n", hookdir);

2008

}

2009

} else {

2010

perror_plus("open");

2011

}

2012

return;

2013

}

2014

}

2015

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

2016

if(devnull == -1){

2017

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

2018

return;

2019

}

2020

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

2021

runnable_hook, alphasort);

1521

2022

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");

2023

perror_plus("scandir");

2024

close(devnull);

2025

return;

2026

}

2027

struct dirent *direntry;

2028

int ret;

2029

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

2030

direntry = direntries[i];

2031

if(debug){

2032

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

2033

direntry->d_name);

1529

2034

}

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){

2035

pid_t hook_pid = fork();

2036

if(hook_pid == 0){

2037

/* Child */

2038

/* Raise privileges */

2039

errno = raise_privileges_permanently();

2040

if(errno != 0){

2041

perror_plus("Failed to raise privileges");

2042

_exit(EX_NOPERM);

2043

}

2044

/* Set group */

2045

errno = 0;

2046

ret = setgid(0);

2047

if(ret == -1){

2048

perror_plus("setgid");

2049

_exit(EX_NOPERM);

2050

}

2051

/* Reset supplementary groups */

2052

errno = 0;

2053

ret = setgroups(0, NULL);

2054

if(ret == -1){

2055

perror_plus("setgroups");

2056

_exit(EX_NOPERM);

2057

}

2058

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

2059

if(ret == -1){

2060

perror_plus("setenv");

2061

_exit(EX_OSERR);

2062

}

2063

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

2064

if(ret == -1){

2065

perror_plus("setenv");

2066

_exit(EX_OSERR);

2067

}

2068

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

2069

if(ret == -1){

2070

perror_plus("setenv");

2071

_exit(EX_OSERR);

2072

}

2073

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

2074

if(ret == -1){

2075

perror_plus("setenv");

2076

_exit(EX_OSERR);

2077

}

2078

char *delaystring;

2079

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

2080

if(ret == -1){

1539

2081

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

}

2082

_exit(EX_OSERR);

2083

}

2084

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

2085

if(ret == -1){

1615

2086

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

}

2087

perror_plus("setenv");

2088

_exit(EX_OSERR);

2089

}

2090

free(delaystring);

2091

if(connect_to != NULL){

2092

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

2093

if(ret == -1){

2094

perror_plus("setenv");

2095

_exit(EX_OSERR);

2096

}

2097

}

2098

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

2099

direntry->d_name,

2100

O_RDONLY));

2101

if(hook_fd == -1){

2102

perror_plus("openat");

2103

_exit(EXIT_FAILURE);

2104

}

2105

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

2106

perror_plus("close");

2107

_exit(EXIT_FAILURE);

2108

}

2109

ret = dup2(devnull, STDIN_FILENO);

2110

if(ret == -1){

2111

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

2112

_exit(EX_OSERR);

2113

}

2114

ret = close(devnull);

2115

if(ret == -1){

2116

perror_plus("close");

2117

_exit(EX_OSERR);

2118

}

2119

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2120

if(ret == -1){

2121

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

2122

_exit(EX_OSERR);

2123

}

2124

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

2125

environ) == -1){

2126

perror_plus("fexecve");

2127

_exit(EXIT_FAILURE);

2128

}

2129

} else {

2130

if(hook_pid == -1){

2131

perror_plus("fork");

2132

free(direntry);

2133

continue;

2134

}

2135

int status;

2136

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

2137

perror_plus("waitpid");

2138

free(direntry);

2139

continue;

2140

}

2141

if(WIFEXITED(status)){

2142

if(WEXITSTATUS(status) != 0){

2143

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

2144

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

2145

WEXITSTATUS(status));

2146

free(direntry);

2147

continue;

2148

}

2149

} else if(WIFSIGNALED(status)){

2150

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

2151

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

2152

WTERMSIG(status));

2153

free(direntry);

2154

continue;

1627

2155

} 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

}

2156

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

2157

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

2158

free(direntry);

2159

continue;

2160

}

2161

}

2162

if(debug){

2163

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

2164

direntry->d_name);

2165

}

2166

free(direntry);

2167

}

2168

free(direntries);

2169

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

2170

perror_plus("close");

2171

} else {

2172

hookdir_fd = -1;

2173

}

2174

close(devnull);

1663

2175

}

1664

2176

1665

2177

__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;

2178

int bring_up_interface(const char *const interface,

2179

const float delay){

2180

int old_errno = errno;

1669

2181

int ret;

1670

2182

struct ifreq network;

1671

2183

unsigned int if_index = if_nametoindex(interface);

1681

2193

}

1682

2194

1683

2195

if(not interface_is_up(interface)){

1684

error_t ret_errno = 0, ioctl_errno = 0;

2196

int ret_errno = 0;

2197

int ioctl_errno = 0;

1685

2198

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

1686

2199

ret_errno = errno;

1687

2200

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

1700

2213

}

1701

2214

1702

2215

if(quit_now){

1703

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

2216

ret = close(sd);

1704

2217

if(ret == -1){

1705

2218

perror_plus("close");

1706

2219

}

1715

2228

1716

2229

/* Raise privileges */

1717

2230

ret_errno = raise_privileges();

2231

if(ret_errno != 0){

2232

errno = ret_errno;

2233

perror_plus("Failed to raise privileges");

2234

}

2235

2236

#ifdef __linux__

2237

int ret_linux;

1718

2238

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

2239

if(ret_errno == 0){

1725

2240

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1726

2241

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

1754

2269

}

1755

2270

1756

2271

/* Close the socket */

1757

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

2272

ret = close(sd);

1758

2273

if(ret == -1){

1759

2274

perror_plus("close");

1760

2275

}

1772

2287

1773

2288

/* Sleep checking until interface is running.

1774

2289

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

1775

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

2290

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

1776

2291

if(interface_is_running(interface)){

1777

2292

break;

1778

2293

}

1788

2303

}

1789

2304

1790

2305

__attribute__((nonnull, warn_unused_result))

1791

error_t take_down_interface(const char *const interface){

1792

error_t old_errno = errno;

2306

int take_down_interface(const char *const interface){

2307

int old_errno = errno;

1793

2308

struct ifreq network;

1794

2309

unsigned int if_index = if_nametoindex(interface);

1795

2310

if(if_index == 0){

1798

2313

return ENXIO;

1799

2314

}

1800

2315

if(interface_is_up(interface)){

1801

error_t ret_errno = 0, ioctl_errno = 0;

2316

int ret_errno = 0;

2317

int ioctl_errno = 0;

1802

2318

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

1803

2319

ret_errno = errno;

1804

2320

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

1824

2340

/* Raise privileges */

1825

2341

ret_errno = raise_privileges();

1826

2342

if(ret_errno != 0){

2343

errno = ret_errno;

1827

2344

perror_plus("Failed to raise privileges");

1828

2345

}

2346

1829

2347

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

1830

2348

ioctl_errno = errno;

1831

2349

1840

2358

}

1841

2359

1842

2360

/* Close the socket */

1843

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

2361

int ret = close(sd);

1844

2362

if(ret == -1){

1845

2363

perror_plus("close");

1846

2364

}

1861

2379

}

1862

2380

1863

2381

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 };

2382

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

2383

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

2384

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

2385

.current_server = NULL, .interfaces = NULL,

2386

.interfaces_size = 0 };

1868

2387

AvahiSServiceBrowser *sb = NULL;

1869

2388

error_t ret_errno;

1870

2389

int ret;

1879

2398

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1880

2399

const char *seckey = PATHDIR "/" SECKEY;

1881

2400

const char *pubkey = PATHDIR "/" PUBKEY;

2401

const char *dh_params_file = NULL;

1882

2402

char *interfaces_hooks = NULL;

1883

2403

1884

2404

bool gnutls_initialized = false;

1937

2457

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

1938

2458

" Diffie-Hellman key exchange",

1939

2459

.group = 2 },

2460

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

2461

.arg = "FILE",

2462

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

2463

" for the Diffie-Hellman key exchange",

2464

.group = 2 },

1940

2465

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

1941

2466

.arg = "STRING",

1942

2467

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

1997

2522

}

1998

2523

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

1999

2524

break;

2525

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

2526

dh_params_file = arg;

2527

break;

2000

2528

case 130: /* --priority */

2001

2529

mc.priority = arg;

2002

2530

break;

2042

2570

.args_doc = "",

2043

2571

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

2044

2572

" passwords from a Mandos server" };

2045

ret = argp_parse(&argp, argc, argv,

2046

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2047

switch(ret){

2573

ret_errno = argp_parse(&argp, argc, argv,

2574

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2575

switch(ret_errno){

2048

2576

case 0:

2049

2577

break;

2050

2578

case ENOMEM:

2051

2579

default:

2052

errno = ret;

2580

errno = ret_errno;

2053

2581

perror_plus("argp_parse");

2054

2582

exitcode = EX_OSERR;

2055

2583

goto end;

2058

2586

goto end;

2059

2587

}

2060

2588

}

2061

2589

2062

2590

{

2063

2591

/* Work around Debian bug #633582:

2064

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

2592

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

2065

2593

2066

2594

/* Re-raise privileges */

2067

ret_errno = raise_privileges();

2068

if(ret_errno != 0){

2069

errno = ret_errno;

2595

ret = raise_privileges();

2596

if(ret != 0){

2597

errno = ret;

2070

2598

perror_plus("Failed to raise privileges");

2071

2599

} else {

2072

2600

struct stat st;

2088

2616

}

2089

2617

}

2090

2618

}

2091

TEMP_FAILURE_RETRY(close(seckey_fd));

2619

close(seckey_fd);

2092

2620

}

2093

2621

}

2094

2622

2095

2623

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

2096

2624

int pubkey_fd = open(pubkey, O_RDONLY);

2097

2625

if(pubkey_fd == -1){

2109

2637

}

2110

2638

}

2111

2639

}

2112

TEMP_FAILURE_RETRY(close(pubkey_fd));

2113

}

2114

}

2115

2640

close(pubkey_fd);

2641

}

2642

}

2643

2644

if(dh_params_file != NULL

2645

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

2646

int dhparams_fd = open(dh_params_file, O_RDONLY);

2647

if(dhparams_fd == -1){

2648

perror_plus("open");

2649

} else {

2650

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

2651

if(ret == -1){

2652

perror_plus("fstat");

2653

} else {

2654

if(S_ISREG(st.st_mode)

2655

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

2656

ret = fchown(dhparams_fd, uid, gid);

2657

if(ret == -1){

2658

perror_plus("fchown");

2659

}

2660

}

2661

}

2662

close(dhparams_fd);

2663

}

2664

}

2665

2116

2666

/* Lower privileges */

2117

ret_errno = lower_privileges();

2118

if(ret_errno != 0){

2119

errno = ret_errno;

2667

ret = lower_privileges();

2668

if(ret != 0){

2669

errno = ret;

2120

2670

perror_plus("Failed to lower privileges");

2121

2671

}

2122

2672

}

2235

2785

2236

2786

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

2237

2787

if(mc.interfaces == NULL){

2238

struct dirent **direntries;

2788

struct dirent **direntries = NULL;

2239

2789

/* Look for any good interfaces */

2240

2790

ret = scandir(sys_class_net, &direntries, good_interface,

2241

2791

alphasort);

2247

2797

if(ret_errno != 0){

2248

2798

errno = ret_errno;

2249

2799

perror_plus("argz_add");

2800

free(direntries[i]);

2250

2801

continue;

2251

2802

}

2252

2803

if(debug){

2253

2804

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

2254

2805

direntries[i]->d_name);

2255

2806

}

2807

free(direntries[i]);

2256

2808

}

2257

2809

free(direntries);

2258

2810

} else {

2259

free(direntries);

2811

if(ret == 0){

2812

free(direntries);

2813

}

2260

2814

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

2261

2815

exitcode = EXIT_FAILURE;

2262

2816

goto end;

2288

2842

errno = bring_up_interface(interface, delay);

2289

2843

if(not interface_was_up){

2290

2844

if(errno != 0){

2291

perror_plus("Failed to bring up interface");

2845

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

2846

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

2292

2847

} else {

2293

2848

errno = argz_add(&interfaces_to_take_down,

2294

2849

&interfaces_to_take_down_size,

2317

2872

goto end;

2318

2873

}

2319

2874

2320

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

2875

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

2321

2876

if(ret == -1){

2322

2877

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

2323

2878

exitcode = EX_UNAVAILABLE;

2445

3000

2446

3001

/* Allocate a new server */

2447

3002

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2448

&config, NULL, NULL, &ret_errno);

3003

&config, NULL, NULL, &ret);

2449

3004

2450

3005

/* Free the Avahi configuration data */

2451

3006

avahi_server_config_free(&config);

2454

3009

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

2455

3010

if(mc.server == NULL){

2456

3011

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

2457

avahi_strerror(ret_errno));

3012

avahi_strerror(ret));

2458

3013

exitcode = EX_UNAVAILABLE;

2459

3014

goto end;

2460

3015

}

2484

3039

if(debug){

2485

3040

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

2486

3041

}

2487

3042

2488

3043

ret = avahi_loop_with_timeout(simple_poll,

2489

3044

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

2490

3045

if(debug){

2495

3050

end:

2496

3051

2497

3052

if(debug){

2498

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

3053

if(signal_received){

3054

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

3055

argv[0], signal_received,

3056

strsignal(signal_received));

3057

} else {

3058

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

3059

}

2499

3060

}

2500

3061

2501

3062

/* Cleanup things */

2512

3073

2513

3074

if(gnutls_initialized){

2514

3075

gnutls_certificate_free_credentials(mc.cred);

2515

gnutls_global_deinit();

2516

3076

gnutls_dh_params_deinit(mc.dh_params);

2517

3077

}

2518

3078

2526

3086

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

2527

3087

while(mc.current_server != NULL){

2528

3088

server *next = mc.current_server->next;

3089

#ifdef __GNUC__

3090

#pragma GCC diagnostic push

3091

#pragma GCC diagnostic ignored "-Wcast-qual"

3092

#endif

3093

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

3094

#ifdef __GNUC__

3095

#pragma GCC diagnostic pop

3096

#endif

2529

3097

free(mc.current_server);

2530

3098

mc.current_server = next;

2531

3099

}

2533

3101

2534

3102

/* Re-raise privileges */

2535

3103

{

2536

ret_errno = raise_privileges();

2537

if(ret_errno != 0){

3104

ret = raise_privileges();

3105

if(ret != 0){

3106

errno = ret;

2538

3107

perror_plus("Failed to raise privileges");

2539

3108

} else {

2540

3109

2545

3114

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

2546

3115

{

2547

3116

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;

3117

while((interface = argz_next(interfaces_to_take_down,

3118

interfaces_to_take_down_size,

3119

interface))){

3120

ret = take_down_interface(interface);

3121

if(ret != 0){

3122

errno = ret;

2554

3123

perror_plus("Failed to take down interface");

2555

3124

}

2556

3125

}

2560

3129

}

2561

3130

}

2562

3131

}

2563

ret_errno = lower_privileges_permanently();

2564

if(ret_errno != 0){

3132

3133

ret = lower_privileges_permanently();

3134

if(ret != 0){

3135

errno = ret;

2565

3136

perror_plus("Failed to lower privileges permanently");

2566

3137

}

2567

3138

}

2569

3140

free(interfaces_to_take_down);

2570

3141

free(interfaces_hooks);

2571

3142

3143

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

3144

uintmax_t level){

3145

struct dirent **direntries = NULL;

3146

int dret;

3147

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

3148

O_RDONLY

3149

| O_NOFOLLOW

3150

| O_DIRECTORY

3151

| O_PATH));

3152

if(dir_fd == -1){

3153

perror_plus("open");

3154

return;

3155

}

3156

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

3157

notdotentries, alphasort);

3158

if(numentries >= 0){

3159

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

3160

if(debug){

3161

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

3162

dirname, direntries[i]->d_name);

3163

}

3164

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

3165

if(dret == -1){

3166

if(errno == EISDIR){

3167

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

3168

AT_REMOVEDIR);

3169

}

3170

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

3171

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

3172

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

3173

/* Recurse only in this special case */

3174

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

3175

dret = 0;

3176

}

3177

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

3178

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

3179

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

3180

}

3181

}

3182

free(direntries[i]);

3183

}

3184

3185

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

3186

free(direntries);

3187

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3188

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

3189

perror_plus("rmdir");

3190

}

3191

} else {

3192

perror_plus("scandirat");

3193

}

3194

close(dir_fd);

3195

}

3196

2572

3197

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

2573

3198

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

}

3199

clean_dir_at(-1, tempdir, 0);

2606

3200

}

2607

3201

2608

3202

if(quit_now){