/mandos/release : revision 237.7.497

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

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*

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* Everything else is

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*

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

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

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* 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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*

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* This file is part of Mandos.

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*

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

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

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* 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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*

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

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* WITHOUT ANY WARRANTY; without even the implied warranty of

22

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

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* General Public License for more details.

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*

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* 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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*

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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

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38

#define _FILE_OFFSET_BITS 64

38

#endif

39

#endif /* not _FILE_OFFSET_BITS */

39

40

41

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

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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

}

412

gpgme_recipient_t recipient;

413

recipient = result->recipients;

414

while(recipient != NULL){

505

506

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

507

r = r->next){

415

508

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

416

gpgme_pubkey_algo_name

417

(recipient->pubkey_algo));

418

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

509

gpgme_pubkey_algo_name(r->pubkey_algo));

510

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

419

511

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

420

recipient->status == GPG_ERR_NO_SECKEY

421

? "No" : "Yes");

422

recipient = recipient->next;

512

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

423

513

}

424

514

}

425

515

}

481

571

return plaintext_length;

482

572

}

483

573

574

__attribute__((warn_unused_result, const))

575

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

576

if(str == NULL)

577

return "(unknown)";

578

return str;

579

}

580

484

581

__attribute__((warn_unused_result))

485

582

static const char *safer_gnutls_strerror(int value){

486

583

const char *ret = gnutls_strerror(value);

487

if(ret == NULL)

488

ret = "(unknown)";

489

return ret;

584

return safe_string(ret);

490

585

}

491

586

492

587

/* GnuTLS log function callback */

496

591

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

497

592

}

498

593

499

__attribute__((nonnull, warn_unused_result))

594

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

500

595

static int init_gnutls_global(const char *pubkeyfilename,

501

596

const char *seckeyfilename,

597

const char *dhparamsfilename,

502

598

mandos_context *mc){

503

599

int ret;

600

unsigned int uret;

504

601

505

602

if(debug){

506

603

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

507

604

}

508

605

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

606

if(debug){

517

607

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

518

608

* - GnuTLS manual

526

616

if(ret != GNUTLS_E_SUCCESS){

527

617

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

528

618

safer_gnutls_strerror(ret));

529

gnutls_global_deinit();

530

619

return -1;

531

620

}

532

621

557

646

safer_gnutls_strerror(ret));

558

647

goto globalfail;

559

648

}

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

649

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

650

if(dhparamsfilename != NULL){

651

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

652

do {

653

int dhpfile = open(dhparamsfilename, O_RDONLY);

654

if(dhpfile == -1){

655

perror_plus("open");

656

dhparamsfilename = NULL;

657

break;

658

}

659

size_t params_capacity = 0;

660

while(true){

661

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

662

(size_t)params.size,

663

(size_t)params_capacity);

664

if(params_capacity == 0){

665

perror_plus("incbuffer");

666

free(params.data);

667

params.data = NULL;

668

dhparamsfilename = NULL;

669

break;

670

}

671

ssize_t bytes_read = read(dhpfile,

672

params.data + params.size,

673

BUFFER_SIZE);

674

/* EOF */

675

if(bytes_read == 0){

676

break;

677

}

678

/* check bytes_read for failure */

679

if(bytes_read < 0){

680

perror_plus("read");

681

free(params.data);

682

params.data = NULL;

683

dhparamsfilename = NULL;

684

break;

685

}

686

params.size += (unsigned int)bytes_read;

687

}

688

ret = close(dhpfile);

689

if(ret == -1){

690

perror_plus("close");

691

}

692

if(params.data == NULL){

693

dhparamsfilename = NULL;

694

}

695

if(dhparamsfilename == NULL){

696

break;

697

}

698

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

699

GNUTLS_X509_FMT_PEM);

700

if(ret != GNUTLS_E_SUCCESS){

701

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

702

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

703

safer_gnutls_strerror(ret));

704

dhparamsfilename = NULL;

705

}

706

free(params.data);

707

} while(false);

708

}

709

if(dhparamsfilename == NULL){

710

if(mc->dh_bits == 0){

711

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

712

/* Try to read the private key file */

713

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

714

do {

715

int secfile = open(seckeyfilename, O_RDONLY);

716

if(secfile == -1){

717

perror_plus("open");

718

break;

719

}

720

size_t buffer_capacity = 0;

721

while(true){

722

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

723

(size_t)buffer.size,

724

(size_t)buffer_capacity);

725

if(buffer_capacity == 0){

726

perror_plus("incbuffer");

727

free(buffer.data);

728

buffer.data = NULL;

729

break;

730

}

731

ssize_t bytes_read = read(secfile,

732

buffer.data + buffer.size,

733

BUFFER_SIZE);

734

/* EOF */

735

if(bytes_read == 0){

736

break;

737

}

738

/* check bytes_read for failure */

739

if(bytes_read < 0){

740

perror_plus("read");

741

free(buffer.data);

742

buffer.data = NULL;

743

break;

744

}

745

buffer.size += (unsigned int)bytes_read;

746

}

747

close(secfile);

748

} while(false);

749

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

750

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

751

if(buffer.data != NULL){

752

{

753

gnutls_openpgp_privkey_t privkey = NULL;

754

ret = gnutls_openpgp_privkey_init(&privkey);

755

if(ret != GNUTLS_E_SUCCESS){

756

fprintf_plus(stderr, "Error initializing OpenPGP key"

757

" structure: %s",

758

safer_gnutls_strerror(ret));

759

free(buffer.data);

760

buffer.data = NULL;

761

} else {

762

ret = gnutls_openpgp_privkey_import

763

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

764

if(ret != GNUTLS_E_SUCCESS){

765

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

766

safer_gnutls_strerror(ret));

767

privkey = NULL;

768

}

769

free(buffer.data);

770

buffer.data = NULL;

771

if(privkey != NULL){

772

/* Use private key to suggest an appropriate

773

sec_param */

774

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

775

gnutls_openpgp_privkey_deinit(privkey);

776

if(debug){

777

fprintf_plus(stderr, "This OpenPGP key implies using"

778

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

779

safe_string(gnutls_sec_param_get_name

780

(sec_param)));

781

}

782

}

783

}

784

}

785

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

786

/* Err on the side of caution */

787

sec_param = GNUTLS_SEC_PARAM_ULTRA;

788

if(debug){

789

fprintf_plus(stderr, "Falling back to security parameter"

790

" \"%s\"\n",

791

safe_string(gnutls_sec_param_get_name

792

(sec_param)));

793

}

794

}

795

}

796

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

797

if(uret != 0){

798

mc->dh_bits = uret;

799

if(debug){

800

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

801

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

802

safe_string(gnutls_sec_param_get_name

803

(sec_param)),

804

mc->dh_bits);

805

}

806

} else {

807

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

808

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

809

safe_string(gnutls_sec_param_get_name

810

(sec_param)),

811

safer_gnutls_strerror(ret));

812

goto globalfail;

813

}

814

} else if(debug){

815

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

816

mc->dh_bits);

817

}

818

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

819

if(ret != GNUTLS_E_SUCCESS){

820

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

821

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

822

safer_gnutls_strerror(ret));

823

goto globalfail;

824

}

825

}

567

826

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

568

827

569

828

return 0;

571

830

globalfail:

572

831

573

832

gnutls_certificate_free_credentials(mc->cred);

574

gnutls_global_deinit();

575

833

gnutls_dh_params_deinit(mc->dh_params);

576

834

return -1;

577

835

}

629

887

/* ignore client certificate if any. */

630

888

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

631

889

632

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

633

634

890

return 0;

635

891

}

636

892

638

894

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

639

895

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

640

896

897

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

898

__attribute__((warn_unused_result))

899

int raise_privileges(void){

900

int old_errno = errno;

901

int ret = 0;

902

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

903

ret = errno;

904

}

905

errno = old_errno;

906

return ret;

907

}

908

909

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

910

__attribute__((warn_unused_result))

911

int raise_privileges_permanently(void){

912

int old_errno = errno;

913

int ret = raise_privileges();

914

if(ret != 0){

915

errno = old_errno;

916

return ret;

917

}

918

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

919

ret = errno;

920

}

921

errno = old_errno;

922

return ret;

923

}

924

925

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

926

__attribute__((warn_unused_result))

927

int lower_privileges(void){

928

int old_errno = errno;

929

int ret = 0;

930

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

931

ret = errno;

932

}

933

errno = old_errno;

934

return ret;

935

}

936

937

/* Lower privileges permanently */

938

__attribute__((warn_unused_result))

939

int lower_privileges_permanently(void){

940

int old_errno = errno;

941

int ret = 0;

942

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

943

ret = errno;

944

}

945

errno = old_errno;

946

return ret;

947

}

948

949

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

950

__attribute__((nonnull, warn_unused_result))

951

static bool add_delete_local_route(const bool add,

952

const char *address,

953

AvahiIfIndex if_index){

954

int ret;

955

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

956

char add_arg[] = "add";

957

char delete_arg[] = "delete";

958

char debug_flag[] = "--debug";

959

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

960

if(pluginhelperdir == NULL){

961

if(debug){

962

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

963

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

964

}

965

return false;

966

}

967

968

char interface[IF_NAMESIZE];

969

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

970

perror_plus("if_indextoname");

971

return false;

972

}

973

974

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

975

if(devnull == -1){

976

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

977

return false;

978

}

979

pid_t pid = fork();

980

if(pid == 0){

981

/* Child */

982

/* Raise privileges */

983

errno = raise_privileges_permanently();

984

if(errno != 0){

985

perror_plus("Failed to raise privileges");

986

/* _exit(EX_NOPERM); */

987

} else {

988

/* Set group */

989

errno = 0;

990

ret = setgid(0);

991

if(ret == -1){

992

perror_plus("setgid");

993

_exit(EX_NOPERM);

994

}

995

/* Reset supplementary groups */

996

errno = 0;

997

ret = setgroups(0, NULL);

998

if(ret == -1){

999

perror_plus("setgroups");

1000

_exit(EX_NOPERM);

1001

}

1002

}

1003

ret = dup2(devnull, STDIN_FILENO);

1004

if(ret == -1){

1005

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

1006

_exit(EX_OSERR);

1007

}

1008

ret = close(devnull);

1009

if(ret == -1){

1010

perror_plus("close");

1011

_exit(EX_OSERR);

1012

}

1013

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1014

if(ret == -1){

1015

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

1016

_exit(EX_OSERR);

1017

}

1018

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

1019

O_RDONLY

1020

| O_DIRECTORY

1021

| O_PATH

1022

| O_CLOEXEC));

1023

if(helperdir_fd == -1){

1024

perror_plus("open");

1025

_exit(EX_UNAVAILABLE);

1026

}

1027

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

1028

helper, O_RDONLY));

1029

if(helper_fd == -1){

1030

perror_plus("openat");

1031

close(helperdir_fd);

1032

_exit(EX_UNAVAILABLE);

1033

}

1034

close(helperdir_fd);

1035

#ifdef __GNUC__

1036

#pragma GCC diagnostic push

1037

#pragma GCC diagnostic ignored "-Wcast-qual"

1038

#endif

1039

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

1040

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

1041

interface, debug ? debug_flag : NULL, NULL },

1042

environ) == -1){

1043

#ifdef __GNUC__

1044

#pragma GCC diagnostic pop

1045

#endif

1046

perror_plus("fexecve");

1047

_exit(EXIT_FAILURE);

1048

}

1049

}

1050

if(pid == -1){

1051

perror_plus("fork");

1052

return false;

1053

}

1054

int status;

1055

pid_t pret = -1;

1056

errno = 0;

1057

do {

1058

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

1059

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

1060

int errno_raising = 0;

1061

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

1062

errno_raising = errno;

1063

perror_plus("Failed to raise privileges in order to"

1064

" kill helper program");

1065

}

1066

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

1067

perror_plus("kill");

1068

}

1069

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

1070

perror_plus("Failed to lower privileges after killing"

1071

" helper program");

1072

}

1073

return false;

1074

}

1075

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

1076

if(pret == -1){

1077

perror_plus("waitpid");

1078

return false;

1079

}

1080

if(WIFEXITED(status)){

1081

if(WEXITSTATUS(status) != 0){

1082

fprintf_plus(stderr, "Error: iprouteadddel exited"

1083

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

1084

return false;

1085

}

1086

return true;

1087

}

1088

if(WIFSIGNALED(status)){

1089

fprintf_plus(stderr, "Error: iprouteadddel died by"

1090

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

1091

return false;

1092

}

1093

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

1094

return false;

1095

}

1096

1097

__attribute__((nonnull, warn_unused_result))

1098

static bool add_local_route(const char *address,

1099

AvahiIfIndex if_index){

1100

if(debug){

1101

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

1102

}

1103

return add_delete_local_route(true, address, if_index);

1104

}

1105

1106

__attribute__((nonnull, warn_unused_result))

1107

static bool delete_local_route(const char *address,

1108

AvahiIfIndex if_index){

1109

if(debug){

1110

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

1111

}

1112

return add_delete_local_route(false, address, if_index);

1113

}

1114

641

1115

/* Called when a Mandos server is found */

642

1116

__attribute__((nonnull, warn_unused_result))

643

1117

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

654

1128

int retval = -1;

655

1129

gnutls_session_t session;

656

1130

int pf; /* Protocol family */

1131

bool route_added = false;

657

1132

658

1133

errno = 0;

659

1134

681

1156

bool match = false;

682

1157

{

683

1158

char *interface = NULL;

684

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

685

interface))){

1159

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

1160

mc->interfaces_size,

1161

interface))){

686

1162

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

687

1163

match = true;

688

1164

break;

717

1193

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

718

1194

}

719

1195

720

tcp_sd = socket(pf, SOCK_STREAM, 0);

1196

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

721

1197

if(tcp_sd < 0){

722

1198

int e = errno;

723

1199

perror_plus("socket");

730

1206

goto mandos_end;

731

1207

}

732

1208

733

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

734

1209

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);

1210

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

1211

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

1212

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

737

1213

} 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);

1214

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

1215

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

1216

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

740

1217

}

741

1218

if(ret < 0 ){

742

1219

int e = errno;

812

1289

goto mandos_end;

813

1290

}

814

1291

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;

1292

while(true){

1293

if(af == AF_INET6){

1294

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

1295

sizeof(struct sockaddr_in6));

1296

} else {

1297

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

1298

sizeof(struct sockaddr_in));

1299

}

1300

if(ret < 0){

1301

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

1302

and if_index != AVAHI_IF_UNSPEC

1303

and connect_to == NULL

1304

and not route_added and

1305

((af == AF_INET6 and not

1306

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1307

&to)->sin6_addr)))

1308

or (af == AF_INET and

1309

/* Not a a IPv4LL address */

1310

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

1311

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

1312

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

1313

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

1314

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

1315

connect to a Mandos server announced by Avahi on a server

1316

host with a global address. Work around this by retrying

1317

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

1318

1319

Avahi bug reference:

1320

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

1321

https://bugs.debian.org/587961

1322

*/

1323

if(debug){

1324

fprintf_plus(stderr, "Mandos server unreachable, trying"

1325

" direct route\n");

1326

}

1327

int e = errno;

1328

route_added = add_local_route(ip, if_index);

1329

if(route_added){

1330

continue;

1331

}

1332

errno = e;

1333

}

1334

if(errno != ECONNREFUSED or debug){

1335

int e = errno;

1336

perror_plus("connect");

1337

errno = e;

1338

}

1339

goto mandos_end;

1340

}

1341

1342

if(quit_now){

1343

errno = EINTR;

1344

goto mandos_end;

1345

}

1346

break;

834

1347

}

835

1348

836

1349

const char *out = mandos_protocol_version;

990

1503

&decrypted_buffer, mc);

991

1504

if(decrypted_buffer_size >= 0){

992

1505

1506

clearerr(stdout);

993

1507

written = 0;

994

1508

while(written < (size_t) decrypted_buffer_size){

995

1509

if(quit_now){

1011

1525

}

1012

1526

written += (size_t)ret;

1013

1527

}

1528

ret = fflush(stdout);

1529

if(ret != 0){

1530

int e = errno;

1531

if(debug){

1532

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

1533

strerror(errno));

1534

}

1535

errno = e;

1536

goto mandos_end;

1537

}

1014

1538

retval = 0;

1015

1539

}

1016

1540

}

1019

1543

1020

1544

mandos_end:

1021

1545

{

1546

if(route_added){

1547

if(not delete_local_route(ip, if_index)){

1548

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

1549

" interface %d", ip, if_index);

1550

}

1551

}

1022

1552

int e = errno;

1023

1553

free(decrypted_buffer);

1024

1554

free(buffer);

1025

1555

if(tcp_sd >= 0){

1026

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

1556

ret = close(tcp_sd);

1027

1557

}

1028

1558

if(ret == -1){

1029

1559

if(e == 0){

1041

1571

return retval;

1042

1572

}

1043

1573

1044

__attribute__((nonnull))

1045

1574

static void resolve_callback(AvahiSServiceResolver *r,

1046

1575

AvahiIfIndex interface,

1047

1576

AvahiProtocol proto,

1064

1593

timed out */

1065

1594

1066

1595

if(quit_now){

1596

avahi_s_service_resolver_free(r);

1067

1597

return;

1068

1598

}

1069

1599

1183

1713

__attribute__((nonnull, warn_unused_result))

1184

1714

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

1185

1715

int ret;

1186

error_t ret_errno;

1716

int old_errno;

1187

1717

1188

1718

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

1189

1719

if(s < 0){

1190

ret_errno = errno;

1720

old_errno = errno;

1191

1721

perror_plus("socket");

1192

errno = ret_errno;

1722

errno = old_errno;

1193

1723

return false;

1194

1724

}

1195

strcpy(ifr->ifr_name, ifname);

1725

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

1726

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

1196

1727

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1197

1728

if(ret == -1){

1198

1729

if(debug){

1199

ret_errno = errno;

1730

old_errno = errno;

1200

1731

perror_plus("ioctl SIOCGIFFLAGS");

1201

errno = ret_errno;

1732

errno = old_errno;

1733

}

1734

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

1735

old_errno = errno;

1736

perror_plus("close");

1737

errno = old_errno;

1202

1738

}

1203

1739

return false;

1204

1740

}

1741

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

1742

old_errno = errno;

1743

perror_plus("close");

1744

errno = old_errno;

1745

}

1205

1746

return true;

1206

1747

}

1207

1748

1335

1876

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

1336

1877

"abcdefghijklmnopqrstuvwxyz"

1337

1878

"0123456789"

1338

"_-");

1879

"_.-");

1339

1880

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

1340

1881

/* Contains non-allowed characters */

1341

1882

if(debug){

1345

1886

return 0;

1346

1887

}

1347

1888

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);

1889

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

1356

1890

if(ret == -1){

1357

1891

if(debug){

1358

1892

perror_plus("Could not stat hook");

1456

1990

}

1457

1991

}

1458

1992

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

1993

__attribute__((nonnull))

1516

1994

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

1517

1995

const float delay){

1518

struct dirent **direntries;

1519

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

1520

alphasort);

1996

struct dirent **direntries = NULL;

1997

if(hookdir_fd == -1){

1998

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1999

| O_CLOEXEC);

2000

if(hookdir_fd == -1){

2001

if(errno == ENOENT){

2002

if(debug){

2003

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

2004

" found\n", hookdir);

2005

}

2006

} else {

2007

perror_plus("open");

2008

}

2009

return;

2010

}

2011

}

2012

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

2013

if(devnull == -1){

2014

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

2015

return;

2016

}

2017

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

2018

runnable_hook, alphasort);

1521

2019

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");

2020

perror_plus("scandir");

2021

close(devnull);

2022

return;

2023

}

2024

struct dirent *direntry;

2025

int ret;

2026

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

2027

direntry = direntries[i];

2028

if(debug){

2029

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

2030

direntry->d_name);

1529

2031

}

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){

2032

pid_t hook_pid = fork();

2033

if(hook_pid == 0){

2034

/* Child */

2035

/* Raise privileges */

2036

errno = raise_privileges_permanently();

2037

if(errno != 0){

2038

perror_plus("Failed to raise privileges");

2039

_exit(EX_NOPERM);

2040

}

2041

/* Set group */

2042

errno = 0;

2043

ret = setgid(0);

2044

if(ret == -1){

2045

perror_plus("setgid");

2046

_exit(EX_NOPERM);

2047

}

2048

/* Reset supplementary groups */

2049

errno = 0;

2050

ret = setgroups(0, NULL);

2051

if(ret == -1){

2052

perror_plus("setgroups");

2053

_exit(EX_NOPERM);

2054

}

2055

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

2056

if(ret == -1){

2057

perror_plus("setenv");

2058

_exit(EX_OSERR);

2059

}

2060

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

2061

if(ret == -1){

2062

perror_plus("setenv");

2063

_exit(EX_OSERR);

2064

}

2065

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

2066

if(ret == -1){

2067

perror_plus("setenv");

2068

_exit(EX_OSERR);

2069

}

2070

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

2071

if(ret == -1){

2072

perror_plus("setenv");

2073

_exit(EX_OSERR);

2074

}

2075

char *delaystring;

2076

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

2077

if(ret == -1){

1539

2078

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

}

2079

_exit(EX_OSERR);

2080

}

2081

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

2082

if(ret == -1){

1615

2083

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

}

2084

perror_plus("setenv");

2085

_exit(EX_OSERR);

2086

}

2087

free(delaystring);

2088

if(connect_to != NULL){

2089

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

2090

if(ret == -1){

2091

perror_plus("setenv");

2092

_exit(EX_OSERR);

2093

}

2094

}

2095

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

2096

direntry->d_name,

2097

O_RDONLY));

2098

if(hook_fd == -1){

2099

perror_plus("openat");

2100

_exit(EXIT_FAILURE);

2101

}

2102

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

2103

perror_plus("close");

2104

_exit(EXIT_FAILURE);

2105

}

2106

ret = dup2(devnull, STDIN_FILENO);

2107

if(ret == -1){

2108

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

2109

_exit(EX_OSERR);

2110

}

2111

ret = close(devnull);

2112

if(ret == -1){

2113

perror_plus("close");

2114

_exit(EX_OSERR);

2115

}

2116

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2117

if(ret == -1){

2118

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

2119

_exit(EX_OSERR);

2120

}

2121

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

2122

environ) == -1){

2123

perror_plus("fexecve");

2124

_exit(EXIT_FAILURE);

2125

}

2126

} else {

2127

if(hook_pid == -1){

2128

perror_plus("fork");

2129

free(direntry);

2130

continue;

2131

}

2132

int status;

2133

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

2134

perror_plus("waitpid");

2135

free(direntry);

2136

continue;

2137

}

2138

if(WIFEXITED(status)){

2139

if(WEXITSTATUS(status) != 0){

2140

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

2141

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

2142

WEXITSTATUS(status));

2143

free(direntry);

2144

continue;

2145

}

2146

} else if(WIFSIGNALED(status)){

2147

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

2148

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

2149

WTERMSIG(status));

2150

free(direntry);

2151

continue;

1627

2152

} 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

}

2153

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

2154

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

2155

free(direntry);

2156

continue;

2157

}

2158

}

2159

if(debug){

2160

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

2161

direntry->d_name);

2162

}

2163

free(direntry);

2164

}

2165

free(direntries);

2166

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

2167

perror_plus("close");

2168

} else {

2169

hookdir_fd = -1;

2170

}

2171

close(devnull);

1663

2172

}

1664

2173

1665

2174

__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;

2175

int bring_up_interface(const char *const interface,

2176

const float delay){

2177

int old_errno = errno;

1669

2178

int ret;

1670

2179

struct ifreq network;

1671

2180

unsigned int if_index = if_nametoindex(interface);

1681

2190

}

1682

2191

1683

2192

if(not interface_is_up(interface)){

1684

error_t ret_errno = 0, ioctl_errno = 0;

2193

int ret_errno = 0;

2194

int ioctl_errno = 0;

1685

2195

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

1686

2196

ret_errno = errno;

1687

2197

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

1700

2210

}

1701

2211

1702

2212

if(quit_now){

1703

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

2213

ret = close(sd);

1704

2214

if(ret == -1){

1705

2215

perror_plus("close");

1706

2216

}

1715

2225

1716

2226

/* Raise privileges */

1717

2227

ret_errno = raise_privileges();

2228

if(ret_errno != 0){

2229

errno = ret_errno;

2230

perror_plus("Failed to raise privileges");

2231

}

2232

2233

#ifdef __linux__

2234

int ret_linux;

1718

2235

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

2236

if(ret_errno == 0){

1725

2237

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1726

2238

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

1754

2266

}

1755

2267

1756

2268

/* Close the socket */

1757

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

2269

ret = close(sd);

1758

2270

if(ret == -1){

1759

2271

perror_plus("close");

1760

2272

}

1772

2284

1773

2285

/* Sleep checking until interface is running.

1774

2286

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

1775

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

2287

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

1776

2288

if(interface_is_running(interface)){

1777

2289

break;

1778

2290

}

1788

2300

}

1789

2301

1790

2302

__attribute__((nonnull, warn_unused_result))

1791

error_t take_down_interface(const char *const interface){

1792

error_t old_errno = errno;

2303

int take_down_interface(const char *const interface){

2304

int old_errno = errno;

1793

2305

struct ifreq network;

1794

2306

unsigned int if_index = if_nametoindex(interface);

1795

2307

if(if_index == 0){

1798

2310

return ENXIO;

1799

2311

}

1800

2312

if(interface_is_up(interface)){

1801

error_t ret_errno = 0, ioctl_errno = 0;

2313

int ret_errno = 0;

2314

int ioctl_errno = 0;

1802

2315

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

1803

2316

ret_errno = errno;

1804

2317

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

1824

2337

/* Raise privileges */

1825

2338

ret_errno = raise_privileges();

1826

2339

if(ret_errno != 0){

2340

errno = ret_errno;

1827

2341

perror_plus("Failed to raise privileges");

1828

2342

}

2343

1829

2344

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

1830

2345

ioctl_errno = errno;

1831

2346

1840

2355

}

1841

2356

1842

2357

/* Close the socket */

1843

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

2358

int ret = close(sd);

1844

2359

if(ret == -1){

1845

2360

perror_plus("close");

1846

2361

}

1861

2376

}

1862

2377

1863

2378

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 };

2379

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

2380

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

2381

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

2382

.current_server = NULL, .interfaces = NULL,

2383

.interfaces_size = 0 };

1868

2384

AvahiSServiceBrowser *sb = NULL;

1869

2385

error_t ret_errno;

1870

2386

int ret;

1879

2395

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1880

2396

const char *seckey = PATHDIR "/" SECKEY;

1881

2397

const char *pubkey = PATHDIR "/" PUBKEY;

2398

const char *dh_params_file = NULL;

1882

2399

char *interfaces_hooks = NULL;

1883

2400

1884

2401

bool gnutls_initialized = false;

1937

2454

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

1938

2455

" Diffie-Hellman key exchange",

1939

2456

.group = 2 },

2457

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

2458

.arg = "FILE",

2459

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

2460

" for the Diffie-Hellman key exchange",

2461

.group = 2 },

1940

2462

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

1941

2463

.arg = "STRING",

1942

2464

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

1997

2519

}

1998

2520

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

1999

2521

break;

2522

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

2523

dh_params_file = arg;

2524

break;

2000

2525

case 130: /* --priority */

2001

2526

mc.priority = arg;

2002

2527

break;

2042

2567

.args_doc = "",

2043

2568

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

2044

2569

" passwords from a Mandos server" };

2045

ret = argp_parse(&argp, argc, argv,

2046

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2047

switch(ret){

2570

ret_errno = argp_parse(&argp, argc, argv,

2571

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2572

switch(ret_errno){

2048

2573

case 0:

2049

2574

break;

2050

2575

case ENOMEM:

2051

2576

default:

2052

errno = ret;

2577

errno = ret_errno;

2053

2578

perror_plus("argp_parse");

2054

2579

exitcode = EX_OSERR;

2055

2580

goto end;

2058

2583

goto end;

2059

2584

}

2060

2585

}

2061

2586

2062

2587

{

2063

2588

/* Work around Debian bug #633582:

2064

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

2589

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

2065

2590

2066

2591

/* Re-raise privileges */

2067

ret_errno = raise_privileges();

2068

if(ret_errno != 0){

2069

errno = ret_errno;

2592

ret = raise_privileges();

2593

if(ret != 0){

2594

errno = ret;

2070

2595

perror_plus("Failed to raise privileges");

2071

2596

} else {

2072

2597

struct stat st;

2088

2613

}

2089

2614

}

2090

2615

}

2091

TEMP_FAILURE_RETRY(close(seckey_fd));

2616

close(seckey_fd);

2092

2617

}

2093

2618

}

2094

2619

2095

2620

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

2096

2621

int pubkey_fd = open(pubkey, O_RDONLY);

2097

2622

if(pubkey_fd == -1){

2109

2634

}

2110

2635

}

2111

2636

}

2112

TEMP_FAILURE_RETRY(close(pubkey_fd));

2113

}

2114

}

2115

2637

close(pubkey_fd);

2638

}

2639

}

2640

2641

if(dh_params_file != NULL

2642

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

2643

int dhparams_fd = open(dh_params_file, O_RDONLY);

2644

if(dhparams_fd == -1){

2645

perror_plus("open");

2646

} else {

2647

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

2648

if(ret == -1){

2649

perror_plus("fstat");

2650

} else {

2651

if(S_ISREG(st.st_mode)

2652

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

2653

ret = fchown(dhparams_fd, uid, gid);

2654

if(ret == -1){

2655

perror_plus("fchown");

2656

}

2657

}

2658

}

2659

close(dhparams_fd);

2660

}

2661

}

2662

2116

2663

/* Lower privileges */

2117

ret_errno = lower_privileges();

2118

if(ret_errno != 0){

2119

errno = ret_errno;

2664

ret = lower_privileges();

2665

if(ret != 0){

2666

errno = ret;

2120

2667

perror_plus("Failed to lower privileges");

2121

2668

}

2122

2669

}

2235

2782

2236

2783

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

2237

2784

if(mc.interfaces == NULL){

2238

struct dirent **direntries;

2785

struct dirent **direntries = NULL;

2239

2786

/* Look for any good interfaces */

2240

2787

ret = scandir(sys_class_net, &direntries, good_interface,

2241

2788

alphasort);

2247

2794

if(ret_errno != 0){

2248

2795

errno = ret_errno;

2249

2796

perror_plus("argz_add");

2797

free(direntries[i]);

2250

2798

continue;

2251

2799

}

2252

2800

if(debug){

2253

2801

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

2254

2802

direntries[i]->d_name);

2255

2803

}

2804

free(direntries[i]);

2256

2805

}

2257

2806

free(direntries);

2258

2807

} else {

2259

free(direntries);

2808

if(ret == 0){

2809

free(direntries);

2810

}

2260

2811

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

2261

2812

exitcode = EXIT_FAILURE;

2262

2813

goto end;

2288

2839

errno = bring_up_interface(interface, delay);

2289

2840

if(not interface_was_up){

2290

2841

if(errno != 0){

2291

perror_plus("Failed to bring up interface");

2842

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

2843

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

2292

2844

} else {

2293

2845

errno = argz_add(&interfaces_to_take_down,

2294

2846

&interfaces_to_take_down_size,

2317

2869

goto end;

2318

2870

}

2319

2871

2320

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

2872

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

2321

2873

if(ret == -1){

2322

2874

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

2323

2875

exitcode = EX_UNAVAILABLE;

2445

2997

2446

2998

/* Allocate a new server */

2447

2999

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2448

&config, NULL, NULL, &ret_errno);

3000

&config, NULL, NULL, &ret);

2449

3001

2450

3002

/* Free the Avahi configuration data */

2451

3003

avahi_server_config_free(&config);

2454

3006

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

2455

3007

if(mc.server == NULL){

2456

3008

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

2457

avahi_strerror(ret_errno));

3009

avahi_strerror(ret));

2458

3010

exitcode = EX_UNAVAILABLE;

2459

3011

goto end;

2460

3012

}

2484

3036

if(debug){

2485

3037

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

2486

3038

}

2487

3039

2488

3040

ret = avahi_loop_with_timeout(simple_poll,

2489

3041

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

2490

3042

if(debug){

2495

3047

end:

2496

3048

2497

3049

if(debug){

2498

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

3050

if(signal_received){

3051

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

3052

argv[0], signal_received,

3053

strsignal(signal_received));

3054

} else {

3055

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

3056

}

2499

3057

}

2500

3058

2501

3059

/* Cleanup things */

2512

3070

2513

3071

if(gnutls_initialized){

2514

3072

gnutls_certificate_free_credentials(mc.cred);

2515

gnutls_global_deinit();

2516

3073

gnutls_dh_params_deinit(mc.dh_params);

2517

3074

}

2518

3075

2526

3083

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

2527

3084

while(mc.current_server != NULL){

2528

3085

server *next = mc.current_server->next;

3086

#ifdef __GNUC__

3087

#pragma GCC diagnostic push

3088

#pragma GCC diagnostic ignored "-Wcast-qual"

3089

#endif

3090

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

3091

#ifdef __GNUC__

3092

#pragma GCC diagnostic pop

3093

#endif

2529

3094

free(mc.current_server);

2530

3095

mc.current_server = next;

2531

3096

}

2533

3098

2534

3099

/* Re-raise privileges */

2535

3100

{

2536

ret_errno = raise_privileges();

2537

if(ret_errno != 0){

3101

ret = raise_privileges();

3102

if(ret != 0){

3103

errno = ret;

2538

3104

perror_plus("Failed to raise privileges");

2539

3105

} else {

2540

3106

2545

3111

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

2546

3112

{

2547

3113

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;

3114

while((interface = argz_next(interfaces_to_take_down,

3115

interfaces_to_take_down_size,

3116

interface))){

3117

ret = take_down_interface(interface);

3118

if(ret != 0){

3119

errno = ret;

2554

3120

perror_plus("Failed to take down interface");

2555

3121

}

2556

3122

}

2560

3126

}

2561

3127

}

2562

3128

}

2563

ret_errno = lower_privileges_permanently();

2564

if(ret_errno != 0){

3129

3130

ret = lower_privileges_permanently();

3131

if(ret != 0){

3132

errno = ret;

2565

3133

perror_plus("Failed to lower privileges permanently");

2566

3134

}

2567

3135

}

2569

3137

free(interfaces_to_take_down);

2570

3138

free(interfaces_hooks);

2571

3139

3140

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

3141

uintmax_t level){

3142

struct dirent **direntries = NULL;

3143

int dret;

3144

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

3145

O_RDONLY

3146

| O_NOFOLLOW

3147

| O_DIRECTORY

3148

| O_PATH));

3149

if(dir_fd == -1){

3150

perror_plus("open");

3151

return;

3152

}

3153

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

3154

notdotentries, alphasort);

3155

if(numentries >= 0){

3156

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

3157

if(debug){

3158

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

3159

dirname, direntries[i]->d_name);

3160

}

3161

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

3162

if(dret == -1){

3163

if(errno == EISDIR){

3164

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

3165

AT_REMOVEDIR);

3166

}

3167

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

3168

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

3169

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

3170

/* Recurse only in this special case */

3171

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

3172

dret = 0;

3173

}

3174

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

3175

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

3176

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

3177

}

3178

}

3179

free(direntries[i]);

3180

}

3181

3182

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

3183

free(direntries);

3184

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3185

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

3186

perror_plus("rmdir");

3187

}

3188

} else {

3189

perror_plus("scandirat");

3190

}

3191

close(dir_fd);

3192

}

3193

2572

3194

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

2573

3195

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

}

3196

clean_dir_at(-1, tempdir, 0);

2606

3197

}

2607

3198

2608

3199

if(quit_now){