/mandos/release : revision 237.7.242

9

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

10

*

11

* Everything else is

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13

14

*

15

* This file is part of Mandos.

16

*

17

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

18

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

19

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

20

* (at your option) any later version.

21

*

22

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

12

13

14

*

15

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

16

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

17

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

18

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

19

*

20

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

23

21

* WITHOUT ANY WARRANTY; without even the implied warranty of

24

22

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

25

23

* General Public License for more details.

26

24

*

27

25

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

28

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

26

* along with this program. If not, see

27

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

29

28

*

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29

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

31

30

*/

47

46

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

48

47

strtof(), abort() */

49

48

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

50

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

51

asprintf(), strncpy(), strsignal()

52

*/

49

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

50

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

53

51

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

54

52

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

55

53

sockaddr_in6, PF_INET6,

59

57

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

60

58

inet_pton(), connect(),

61

59

getnameinfo() */

62

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

60

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

63

61

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

64

62

*/

65

63

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

66

64

strtoimax() */

67

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

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

65

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

72

66

program_invocation_short_name */

73

67

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

74

68

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

123

117

gnutls_*

124

118

init_gnutls_session(),

125

119

GNUTLS_* */

126

#if GNUTLS_VERSION_NUMBER < 0x030600

127

120

#include <gnutls/openpgp.h>

128

121

/* gnutls_certificate_set_openpgp_key_file(),

129

122

GNUTLS_OPENPGP_FMT_BASE64 */

130

#elif GNUTLS_VERSION_NUMBER >= 0x030606

131

#include <gnutls/x509.h> /* gnutls_pkcs_encrypt_flags_t,

132

GNUTLS_PKCS_PLAIN,

133

GNUTLS_PKCS_NULL_PASSWORD */

134

#endif

135

123

136

124

/* GPGME */

137

125

#include <gpgme.h> /* All GPGME types, constants and

145

133

#define PATHDIR "/conf/conf.d/mandos"

146

134

#define SECKEY "seckey.txt"

147

135

#define PUBKEY "pubkey.txt"

148

#define TLS_PRIVKEY "tls-privkey.pem"

149

#define TLS_PUBKEY "tls-pubkey.pem"

150

136

#define HOOKDIR "/lib/mandos/network-hooks.d"

151

137

152

138

bool debug = false;

248

234

.af = af };

249

235

if(new_server->ip == NULL){

250

236

perror_plus("strdup");

251

free(new_server);

252

237

return false;

253

238

}

254

239

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

255

240

if(ret == -1){

256

241

perror_plus("clock_gettime");

257

#ifdef __GNUC__

258

#pragma GCC diagnostic push

259

#pragma GCC diagnostic ignored "-Wcast-qual"

260

#endif

261

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

262

#ifdef __GNUC__

263

#pragma GCC diagnostic pop

264

#endif

265

free(new_server);

266

242

return false;

267

243

}

268

244

/* Special case of first server */

280

256

return true;

281

257

}

282

258

283

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

284

__attribute__((warn_unused_result))

285

int raise_privileges(void){

286

int old_errno = errno;

287

int ret = 0;

288

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

289

ret = errno;

290

}

291

errno = old_errno;

292

return ret;

293

}

294

295

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

296

__attribute__((warn_unused_result))

297

int raise_privileges_permanently(void){

298

int old_errno = errno;

299

int ret = raise_privileges();

300

if(ret != 0){

301

errno = old_errno;

302

return ret;

303

}

304

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

305

ret = errno;

306

}

307

errno = old_errno;

308

return ret;

309

}

310

311

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

312

__attribute__((warn_unused_result))

313

int lower_privileges(void){

314

int old_errno = errno;

315

int ret = 0;

316

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

317

ret = errno;

318

}

319

errno = old_errno;

320

return ret;

321

}

322

323

/* Lower privileges permanently */

324

__attribute__((warn_unused_result))

325

int lower_privileges_permanently(void){

326

int old_errno = errno;

327

int ret = 0;

328

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

329

ret = errno;

330

}

331

errno = old_errno;

332

return ret;

333

}

334

335

259

/*

336

260

* Initialize GPGME.

337

261

*/

357

281

return false;

358

282

}

359

283

360

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

361

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

362

do {

363

{

364

time_t currtime = time(NULL);

365

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

366

struct tm tm;

367

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

368

perror_plus("gmtime_r");

369

break;

370

}

371

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

372

break;

373

}

374

if(debug){

375

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

376

}

377

} else {

378

if(debug){

379

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

380

}

381

}

382

}

383

struct stat keystat;

384

ret = fstat(fd, &keystat);

385

if(ret != 0){

386

perror_plus("fstat");

387

break;

388

}

389

ret = raise_privileges();

390

if(ret != 0){

391

errno = ret;

392

perror_plus("Failed to raise privileges");

393

break;

394

}

395

if(debug){

396

fprintf_plus(stderr,

397

"Setting system clock to key file mtime");

398

}

399

time_t keytime = keystat.st_mtim.tv_sec;

400

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

401

perror_plus("stime");

402

}

403

ret = lower_privileges();

404

if(ret != 0){

405

errno = ret;

406

perror_plus("Failed to lower privileges");

407

}

408

} while(false);

409

410

284

rc = gpgme_data_new_from_fd(&pgp_data, fd);

411

285

if(rc != GPG_ERR_NO_ERROR){

412

286

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

420

294

gpgme_strsource(rc), gpgme_strerror(rc));

421

295

return false;

422

296

}

423

{

424

gpgme_import_result_t import_result

425

= gpgme_op_import_result(mc->ctx);

426

if((import_result->imported < 1

427

or import_result->not_imported > 0)

428

and import_result->unchanged == 0){

429

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

430

fprintf_plus(stderr,

431

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

432

import_result->considered);

433

fprintf_plus(stderr,

434

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

435

import_result->no_user_id);

436

fprintf_plus(stderr,

437

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

438

import_result->imported);

439

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

440

import_result->imported_rsa);

441

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

442

import_result->unchanged);

443

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

444

import_result->new_user_ids);

445

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

446

import_result->new_sub_keys);

447

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

448

import_result->new_signatures);

449

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

450

import_result->new_revocations);

451

fprintf_plus(stderr,

452

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

453

import_result->secret_read);

454

fprintf_plus(stderr,

455

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

456

import_result->secret_imported);

457

fprintf_plus(stderr,

458

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

459

import_result->secret_unchanged);

460

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

461

import_result->not_imported);

462

for(gpgme_import_status_t import_status

463

= import_result->imports;

464

import_status != NULL;

465

import_status = import_status->next){

466

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

467

import_status->fpr);

468

if(import_status->result != GPG_ERR_NO_ERROR){

469

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

470

gpgme_strsource(import_status->result),

471

gpgme_strerror(import_status->result));

472

}

473

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

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_NEW

476

? "The key was new.\n"

477

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

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_UID

480

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

481

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

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SIG

484

? "The key contained new signatures.\n"

485

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

486

fprintf_plus(stderr,

487

import_status->status & GPGME_IMPORT_SUBKEY

488

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

489

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

490

fprintf_plus(stderr,

491

import_status->status & GPGME_IMPORT_SECRET

492

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

493

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

494

}

495

return false;

496

}

497

}

498

297

499

ret = close(fd);

298

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

500

299

if(ret == -1){

501

300

perror_plus("close");

502

301

}

541

340

/* Create new GPGME "context" */

542

341

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

543

342

if(rc != GPG_ERR_NO_ERROR){

544

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

545

gpgme_strsource(rc), gpgme_strerror(rc));

343

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

344

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

345

gpgme_strerror(rc));

546

346

return false;

547

347

}

548

348

584

384

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

585

385

rc = gpgme_data_new(&dh_plain);

586

386

if(rc != GPG_ERR_NO_ERROR){

587

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

387

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

388

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

588

389

gpgme_strsource(rc), gpgme_strerror(rc));

589

390

gpgme_data_release(dh_crypto);

590

391

return -1;

603

404

if(result == NULL){

604

405

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

605

406

} else {

606

if(result->unsupported_algorithm != NULL) {

607

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

608

result->unsupported_algorithm);

609

}

610

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

611

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

407

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

408

result->unsupported_algorithm);

409

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

410

result->wrong_key_usage);

612

411

if(result->file_name != NULL){

613

412

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

614

413

}

615

616

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

617

r = r->next){

414

gpgme_recipient_t recipient;

415

recipient = result->recipients;

416

while(recipient != NULL){

618

417

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

619

gpgme_pubkey_algo_name(r->pubkey_algo));

620

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

418

gpgme_pubkey_algo_name

419

(recipient->pubkey_algo));

420

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

621

421

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

622

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

422

recipient->status == GPG_ERR_NO_SECKEY

423

? "No" : "Yes");

424

recipient = recipient->next;

623

425

}

624

426

}

625

427

}

681

483

return plaintext_length;

682

484

}

683

485

684

__attribute__((warn_unused_result, const))

685

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

686

if(str == NULL)

687

return "(unknown)";

688

return str;

689

}

690

691

486

__attribute__((warn_unused_result))

692

487

static const char *safer_gnutls_strerror(int value){

693

488

const char *ret = gnutls_strerror(value);

694

return safe_string(ret);

489

if(ret == NULL)

490

ret = "(unknown)";

491

return ret;

695

492

}

696

493

697

494

/* GnuTLS log function callback */

701

498

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

702

499

}

703

500

704

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

501

__attribute__((nonnull, warn_unused_result))

705

502

static int init_gnutls_global(const char *pubkeyfilename,

706

503

const char *seckeyfilename,

707

const char *dhparamsfilename,

708

504

mandos_context *mc){

709

505

int ret;

710

506

712

508

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

713

509

}

714

510

511

ret = gnutls_global_init();

512

if(ret != GNUTLS_E_SUCCESS){

513

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

514

safer_gnutls_strerror(ret));

515

return -1;

516

}

517

715

518

if(debug){

716

519

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

717

520

* - GnuTLS manual

725

528

if(ret != GNUTLS_E_SUCCESS){

726

529

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

727

530

safer_gnutls_strerror(ret));

531

gnutls_global_deinit();

728

532

return -1;

729

533

}

730

534

731

535

if(debug){

732

fprintf_plus(stderr, "Attempting to use public key %s and"

733

" private key %s as GnuTLS credentials\n",

536

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

537

" secret key %s as GnuTLS credentials\n",

734

538

pubkeyfilename,

735

539

seckeyfilename);

736

540

}

737

541

738

#if GNUTLS_VERSION_NUMBER >= 0x030606

739

ret = gnutls_certificate_set_rawpk_key_file

740

(mc->cred, pubkeyfilename, seckeyfilename,

741

GNUTLS_X509_FMT_PEM, /* format */

742

NULL, /* pass */

743

/* key_usage */

744

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

745

NULL, /* names */

746

0, /* names_length */

747

/* privkey_flags */

748

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

749

0); /* pkcs11_flags */

750

#elif GNUTLS_VERSION_NUMBER < 0x030600

751

542

ret = gnutls_certificate_set_openpgp_key_file

752

543

(mc->cred, pubkeyfilename, seckeyfilename,

753

544

GNUTLS_OPENPGP_FMT_BASE64);

754

#else

755

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

756

#endif

757

545

if(ret != GNUTLS_E_SUCCESS){

758

546

fprintf_plus(stderr,

759

"Error[%d] while reading the key pair ('%s',"

547

"Error[%d] while reading the OpenPGP key pair ('%s',"

760

548

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

761

549

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

762

550

safer_gnutls_strerror(ret));

771

559

safer_gnutls_strerror(ret));

772

560

goto globalfail;

773

561

}

774

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

775

if(dhparamsfilename != NULL){

776

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

777

do {

778

int dhpfile = open(dhparamsfilename, O_RDONLY);

779

if(dhpfile == -1){

780

perror_plus("open");

781

dhparamsfilename = NULL;

782

break;

783

}

784

size_t params_capacity = 0;

785

while(true){

786

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

787

(size_t)params.size,

788

(size_t)params_capacity);

789

if(params_capacity == 0){

790

perror_plus("incbuffer");

791

free(params.data);

792

params.data = NULL;

793

dhparamsfilename = NULL;

794

break;

795

}

796

ssize_t bytes_read = read(dhpfile,

797

params.data + params.size,

798

BUFFER_SIZE);

799

/* EOF */

800

if(bytes_read == 0){

801

break;

802

}

803

/* check bytes_read for failure */

804

if(bytes_read < 0){

805

perror_plus("read");

806

free(params.data);

807

params.data = NULL;

808

dhparamsfilename = NULL;

809

break;

810

}

811

params.size += (unsigned int)bytes_read;

812

}

813

ret = close(dhpfile);

814

if(ret == -1){

815

perror_plus("close");

816

}

817

if(params.data == NULL){

818

dhparamsfilename = NULL;

819

}

820

if(dhparamsfilename == NULL){

821

break;

822

}

823

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

824

GNUTLS_X509_FMT_PEM);

825

if(ret != GNUTLS_E_SUCCESS){

826

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

827

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

828

safer_gnutls_strerror(ret));

829

dhparamsfilename = NULL;

830

}

831

free(params.data);

832

} while(false);

833

}

834

if(dhparamsfilename == NULL){

835

if(mc->dh_bits == 0){

836

#if GNUTLS_VERSION_NUMBER < 0x030600

837

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

838

/* Try to read the private key file */

839

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

840

do {

841

int secfile = open(seckeyfilename, O_RDONLY);

842

if(secfile == -1){

843

perror_plus("open");

844

break;

845

}

846

size_t buffer_capacity = 0;

847

while(true){

848

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

849

(size_t)buffer.size,

850

(size_t)buffer_capacity);

851

if(buffer_capacity == 0){

852

perror_plus("incbuffer");

853

free(buffer.data);

854

buffer.data = NULL;

855

break;

856

}

857

ssize_t bytes_read = read(secfile,

858

buffer.data + buffer.size,

859

BUFFER_SIZE);

860

/* EOF */

861

if(bytes_read == 0){

862

break;

863

}

864

/* check bytes_read for failure */

865

if(bytes_read < 0){

866

perror_plus("read");

867

free(buffer.data);

868

buffer.data = NULL;

869

break;

870

}

871

buffer.size += (unsigned int)bytes_read;

872

}

873

close(secfile);

874

} while(false);

875

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

876

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

877

if(buffer.data != NULL){

878

{

879

gnutls_openpgp_privkey_t privkey = NULL;

880

ret = gnutls_openpgp_privkey_init(&privkey);

881

if(ret != GNUTLS_E_SUCCESS){

882

fprintf_plus(stderr, "Error initializing OpenPGP key"

883

" structure: %s",

884

safer_gnutls_strerror(ret));

885

free(buffer.data);

886

buffer.data = NULL;

887

} else {

888

ret = gnutls_openpgp_privkey_import

889

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

890

if(ret != GNUTLS_E_SUCCESS){

891

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

892

safer_gnutls_strerror(ret));

893

privkey = NULL;

894

}

895

free(buffer.data);

896

buffer.data = NULL;

897

if(privkey != NULL){

898

/* Use private key to suggest an appropriate

899

sec_param */

900

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

901

gnutls_openpgp_privkey_deinit(privkey);

902

if(debug){

903

fprintf_plus(stderr, "This OpenPGP key implies using"

904

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

905

safe_string(gnutls_sec_param_get_name

906

(sec_param)));

907

}

908

}

909

}

910

}

911

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

912

/* Err on the side of caution */

913

sec_param = GNUTLS_SEC_PARAM_ULTRA;

914

if(debug){

915

fprintf_plus(stderr, "Falling back to security parameter"

916

" \"%s\"\n",

917

safe_string(gnutls_sec_param_get_name

918

(sec_param)));

919

}

920

}

921

}

922

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

923

if(uret != 0){

924

mc->dh_bits = uret;

925

if(debug){

926

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

927

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

928

safe_string(gnutls_sec_param_get_name

929

(sec_param)),

930

mc->dh_bits);

931

}

932

} else {

933

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

934

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

935

safe_string(gnutls_sec_param_get_name

936

(sec_param)),

937

safer_gnutls_strerror(ret));

938

goto globalfail;

939

}

940

#endif

941

} else { /* dh_bits != 0 */

942

if(debug){

943

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

944

mc->dh_bits);

945

}

946

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

947

if(ret != GNUTLS_E_SUCCESS){

948

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

949

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

950

safer_gnutls_strerror(ret));

951

goto globalfail;

952

}

953

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

954

}

955

}

562

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

563

if(ret != GNUTLS_E_SUCCESS){

564

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

565

safer_gnutls_strerror(ret));

566

goto globalfail;

567

}

568

569

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

956

570

957

571

return 0;

958

572

959

573

globalfail:

960

574

961

575

gnutls_certificate_free_credentials(mc->cred);

576

gnutls_global_deinit();

962

577

gnutls_dh_params_deinit(mc->dh_params);

963

578

return -1;

964

579

}

969

584

int ret;

970

585

/* GnuTLS session creation */

971

586

do {

972

ret = gnutls_init(session, (GNUTLS_SERVER

973

#if GNUTLS_VERSION_NUMBER >= 0x030506

974

| GNUTLS_NO_TICKETS

975

#endif

976

#if GNUTLS_VERSION_NUMBER >= 0x030606

977

| GNUTLS_ENABLE_RAWPK

978

#endif

979

));

587

ret = gnutls_init(session, GNUTLS_SERVER);

980

588

if(quit_now){

981

589

return -1;

982

590

}

1023

631

/* ignore client certificate if any. */

1024

632

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

1025

633

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

635

1026

636

return 0;

1027

637

}

1028

638

1030

640

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

1031

641

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

1032

642

1033

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

1034

__attribute__((nonnull, warn_unused_result))

1035

static bool add_delete_local_route(const bool add,

1036

const char *address,

1037

AvahiIfIndex if_index){

1038

int ret;

1039

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

1040

char add_arg[] = "add";

1041

char delete_arg[] = "delete";

1042

char debug_flag[] = "--debug";

1043

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1044

if(pluginhelperdir == NULL){

1045

if(debug){

1046

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1047

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

1048

}

1049

return false;

1050

}

1051

1052

char interface[IF_NAMESIZE];

1053

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

1054

perror_plus("if_indextoname");

1055

return false;

1056

}

1057

1058

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

1059

if(devnull == -1){

1060

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

1061

return false;

1062

}

1063

pid_t pid = fork();

1064

if(pid == 0){

1065

/* Child */

1066

/* Raise privileges */

1067

errno = raise_privileges_permanently();

1068

if(errno != 0){

1069

perror_plus("Failed to raise privileges");

1070

/* _exit(EX_NOPERM); */

1071

} else {

1072

/* Set group */

1073

errno = 0;

1074

ret = setgid(0);

1075

if(ret == -1){

1076

perror_plus("setgid");

1077

_exit(EX_NOPERM);

1078

}

1079

/* Reset supplementary groups */

1080

errno = 0;

1081

ret = setgroups(0, NULL);

1082

if(ret == -1){

1083

perror_plus("setgroups");

1084

_exit(EX_NOPERM);

1085

}

1086

}

1087

ret = dup2(devnull, STDIN_FILENO);

1088

if(ret == -1){

1089

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

1090

_exit(EX_OSERR);

1091

}

1092

ret = close(devnull);

1093

if(ret == -1){

1094

perror_plus("close");

1095

_exit(EX_OSERR);

1096

}

1097

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1098

if(ret == -1){

1099

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

1100

_exit(EX_OSERR);

1101

}

1102

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

1103

O_RDONLY

1104

| O_DIRECTORY

1105

| O_PATH

1106

| O_CLOEXEC));

1107

if(helperdir_fd == -1){

1108

perror_plus("open");

1109

_exit(EX_UNAVAILABLE);

1110

}

1111

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

1112

helper, O_RDONLY));

1113

if(helper_fd == -1){

1114

perror_plus("openat");

1115

close(helperdir_fd);

1116

_exit(EX_UNAVAILABLE);

1117

}

1118

close(helperdir_fd);

1119

#ifdef __GNUC__

1120

#pragma GCC diagnostic push

1121

#pragma GCC diagnostic ignored "-Wcast-qual"

1122

#endif

1123

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

1124

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

1125

interface, debug ? debug_flag : NULL, NULL },

1126

environ) == -1){

1127

#ifdef __GNUC__

1128

#pragma GCC diagnostic pop

1129

#endif

1130

perror_plus("fexecve");

1131

_exit(EXIT_FAILURE);

1132

}

1133

}

1134

if(pid == -1){

1135

perror_plus("fork");

1136

return false;

1137

}

1138

int status;

1139

pid_t pret = -1;

1140

errno = 0;

1141

do {

1142

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

1143

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

1144

int errno_raising = 0;

1145

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

1146

errno_raising = errno;

1147

perror_plus("Failed to raise privileges in order to"

1148

" kill helper program");

1149

}

1150

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

1151

perror_plus("kill");

1152

}

1153

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

1154

perror_plus("Failed to lower privileges after killing"

1155

" helper program");

1156

}

1157

return false;

1158

}

1159

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

1160

if(pret == -1){

1161

perror_plus("waitpid");

1162

return false;

1163

}

1164

if(WIFEXITED(status)){

1165

if(WEXITSTATUS(status) != 0){

1166

fprintf_plus(stderr, "Error: iprouteadddel exited"

1167

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

1168

return false;

1169

}

1170

return true;

1171

}

1172

if(WIFSIGNALED(status)){

1173

fprintf_plus(stderr, "Error: iprouteadddel died by"

1174

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

1175

return false;

1176

}

1177

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

1178

return false;

1179

}

1180

1181

__attribute__((nonnull, warn_unused_result))

1182

static bool add_local_route(const char *address,

1183

AvahiIfIndex if_index){

1184

if(debug){

1185

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

1186

}

1187

return add_delete_local_route(true, address, if_index);

1188

}

1189

1190

__attribute__((nonnull, warn_unused_result))

1191

static bool delete_local_route(const char *address,

1192

AvahiIfIndex if_index){

1193

if(debug){

1194

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

1195

}

1196

return add_delete_local_route(false, address, if_index);

1197

}

1198

1199

643

/* Called when a Mandos server is found */

1200

644

__attribute__((nonnull, warn_unused_result))

1201

645

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

1212

656

int retval = -1;

1213

657

gnutls_session_t session;

1214

658

int pf; /* Protocol family */

1215

bool route_added = false;

1216

659

1217

660

errno = 0;

1218

661

1240

683

bool match = false;

1241

684

{

1242

685

char *interface = NULL;

1243

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

1244

mc->interfaces_size,

1245

interface))){

686

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

687

interface))){

1246

688

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

1247

689

match = true;

1248

690

break;

1277

719

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

1278

720

}

1279

721

1280

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

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

1281

723

if(tcp_sd < 0){

1282

724

int e = errno;

1283

725

perror_plus("socket");

1290

732

goto mandos_end;

1291

733

}

1292

734

735

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

1293

736

if(af == AF_INET6){

1294

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

1295

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

1296

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

737

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

738

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

1297

739

} else { /* IPv4 */

1298

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

1299

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

1300

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

740

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

741

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

1301

742

}

1302

743

if(ret < 0 ){

1303

744

int e = errno;

1373

814

goto mandos_end;

1374

815

}

1375

816

1376

while(true){

1377

if(af == AF_INET6){

1378

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

1379

sizeof(struct sockaddr_in6));

1380

} else {

1381

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

1382

sizeof(struct sockaddr_in));

1383

}

1384

if(ret < 0){

1385

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

1386

and if_index != AVAHI_IF_UNSPEC

1387

and connect_to == NULL

1388

and not route_added and

1389

((af == AF_INET6 and not

1390

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1391

&to)->sin6_addr)))

1392

or (af == AF_INET and

1393

/* Not a a IPv4LL address */

1394

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

1395

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

1396

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

1397

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

1398

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

1399

connect to a Mandos server announced by Avahi on a server

1400

host with a global address. Work around this by retrying

1401

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

1402

1403

Avahi bug reference:

1404

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

1405

https://bugs.debian.org/587961

1406

*/

1407

if(debug){

1408

fprintf_plus(stderr, "Mandos server unreachable, trying"

1409

" direct route\n");

1410

}

1411

int e = errno;

1412

route_added = add_local_route(ip, if_index);

1413

if(route_added){

1414

continue;

1415

}

1416

errno = e;

1417

}

1418

if(errno != ECONNREFUSED or debug){

1419

int e = errno;

1420

perror_plus("connect");

1421

errno = e;

1422

}

1423

goto mandos_end;

1424

}

1425

1426

if(quit_now){

1427

errno = EINTR;

1428

goto mandos_end;

1429

}

1430

break;

817

if(af == AF_INET6){

818

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

819

sizeof(struct sockaddr_in6));

820

} else {

821

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

822

sizeof(struct sockaddr_in));

823

}

824

if(ret < 0){

825

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

826

int e = errno;

827

perror_plus("connect");

828

errno = e;

829

}

830

goto mandos_end;

831

}

832

833

if(quit_now){

834

errno = EINTR;

835

goto mandos_end;

1431

836

}

1432

837

1433

838

const char *out = mandos_protocol_version;

1587

992

&decrypted_buffer, mc);

1588

993

if(decrypted_buffer_size >= 0){

1589

994

1590

clearerr(stdout);

1591

995

written = 0;

1592

996

while(written < (size_t) decrypted_buffer_size){

1593

997

if(quit_now){

1609

1013

}

1610

1014

written += (size_t)ret;

1611

1015

}

1612

ret = fflush(stdout);

1613

if(ret != 0){

1614

int e = errno;

1615

if(debug){

1616

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

1617

strerror(errno));

1618

}

1619

errno = e;

1620

goto mandos_end;

1621

}

1622

1016

retval = 0;

1623

1017

}

1624

1018

}

1627

1021

1628

1022

mandos_end:

1629

1023

{

1630

if(route_added){

1631

if(not delete_local_route(ip, if_index)){

1632

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

1633

" interface %d", ip, if_index);

1634

}

1635

}

1636

1024

int e = errno;

1637

1025

free(decrypted_buffer);

1638

1026

free(buffer);

1639

1027

if(tcp_sd >= 0){

1640

ret = close(tcp_sd);

1028

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

1641

1029

}

1642

1030

if(ret == -1){

1643

1031

if(e == 0){

1655

1043

return retval;

1656

1044

}

1657

1045

1046

__attribute__((nonnull))

1658

1047

static void resolve_callback(AvahiSServiceResolver *r,

1659

1048

AvahiIfIndex interface,

1660

1049

AvahiProtocol proto,

1677

1066

timed out */

1678

1067

1679

1068

if(quit_now){

1680

avahi_s_service_resolver_free(r);

1681

1069

return;

1682

1070

}

1683

1071

1797

1185

__attribute__((nonnull, warn_unused_result))

1798

1186

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

1799

1187

int ret;

1800

int old_errno;

1188

error_t ret_errno;

1801

1189

1802

1190

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

1803

1191

if(s < 0){

1804

old_errno = errno;

1192

ret_errno = errno;

1805

1193

perror_plus("socket");

1806

errno = old_errno;

1194

errno = ret_errno;

1807

1195

return false;

1808

1196

}

1809

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

1810

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

1197

strcpy(ifr->ifr_name, ifname);

1811

1198

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1812

1199

if(ret == -1){

1813

1200

if(debug){

1814

old_errno = errno;

1201

ret_errno = errno;

1815

1202

perror_plus("ioctl SIOCGIFFLAGS");

1816

errno = old_errno;

1817

}

1818

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

1819

old_errno = errno;

1820

perror_plus("close");

1821

errno = old_errno;

1203

errno = ret_errno;

1822

1204

}

1823

1205

return false;

1824

1206

}

1825

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

1826

old_errno = errno;

1827

perror_plus("close");

1828

errno = old_errno;

1829

}

1830

1207

return true;

1831

1208

}

1832

1209

2074

1451

}

2075

1452

}

2076

1453

1454

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

1455

__attribute__((warn_unused_result))

1456

error_t raise_privileges(void){

1457

error_t old_errno = errno;

1458

error_t ret_errno = 0;

1459

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

1460

ret_errno = errno;

1461

perror_plus("seteuid");

1462

}

1463

errno = old_errno;

1464

return ret_errno;

1465

}

1466

1467

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

1468

__attribute__((warn_unused_result))

1469

error_t raise_privileges_permanently(void){

1470

error_t old_errno = errno;

1471

error_t ret_errno = raise_privileges();

1472

if(ret_errno != 0){

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

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

1477

ret_errno = errno;

1478

perror_plus("seteuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1485

__attribute__((warn_unused_result))

1486

error_t lower_privileges(void){

1487

error_t old_errno = errno;

1488

error_t ret_errno = 0;

1489

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

1490

ret_errno = errno;

1491

perror_plus("seteuid");

1492

}

1493

errno = old_errno;

1494

return ret_errno;

1495

}

1496

1497

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1499

error_t lower_privileges_permanently(void){

1500

error_t old_errno = errno;

1501

error_t ret_errno = 0;

1502

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

1503

ret_errno = errno;

1504

perror_plus("setuid");

1505

}

1506

errno = old_errno;

1507

return ret_errno;

1508

}

1509

1510

#ifndef O_CLOEXEC

1511

/*

1512

* Based on the example in the GNU LibC manual chapter 13.13 "File

1513

* Descriptor Flags".

1514

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

1515

*/

1516

__attribute__((warn_unused_result))

1517

static int set_cloexec_flag(int fd){

1518

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

1519

/* If reading the flags failed, return error indication now. */

1520

if(ret < 0){

1521

return ret;

1522

}

1523

/* Store modified flag word in the descriptor. */

1524

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

1525

ret | FD_CLOEXEC));

1526

}

1527

#endif /* not O_CLOEXEC */

1528

2077

1529

__attribute__((nonnull))

2078

1530

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

2079

1531

const float delay){

2080

struct dirent **direntries = NULL;

1532

struct dirent **direntries;

2081

1533

if(hookdir_fd == -1){

2082

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2083

| O_CLOEXEC);

1534

hookdir_fd = open(hookdir, O_RDONLY |

1535

#ifdef O_CLOEXEC

1536

O_CLOEXEC

1537

#else /* not O_CLOEXEC */

1538

0

1539

#endif /* not O_CLOEXEC */

1540

);

2084

1541

if(hookdir_fd == -1){

2085

1542

if(errno == ENOENT){

2086

1543

if(debug){

2092

1549

}

2093

1550

return;

2094

1551

}

2095

}

2096

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

2097

if(devnull == -1){

2098

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

2099

return;

2100

}

1552

#ifndef O_CLOEXEC

1553

if(set_cloexec_flag(hookdir_fd) < 0){

1554

perror_plus("set_cloexec_flag");

1555

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

1556

perror_plus("close");

1557

} else {

1558

hookdir_fd = -1;

1559

}

1560

return;

1561

}

1562

#endif /* not O_CLOEXEC */

1563

}

1564

#ifdef __GLIBC__

1565

#if __GLIBC_PREREQ(2, 15)

2101

1566

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

2102

1567

runnable_hook, alphasort);

1568

#else /* not __GLIBC_PREREQ(2, 15) */

1569

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

1570

alphasort);

1571

#endif /* not __GLIBC_PREREQ(2, 15) */

1572

#else /* not __GLIBC__ */

1573

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

1574

alphasort);

1575

#endif /* not __GLIBC__ */

2103

1576

if(numhooks == -1){

2104

1577

perror_plus("scandir");

2105

close(devnull);

2106

1578

return;

2107

1579

}

2108

1580

struct dirent *direntry;

2109

1581

int ret;

1582

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

2110

1583

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

2111

1584

direntry = direntries[i];

2112

1585

if(debug){

2117

1590

if(hook_pid == 0){

2118

1591

/* Child */

2119

1592

/* Raise privileges */

2120

errno = raise_privileges_permanently();

2121

if(errno != 0){

1593

if(raise_privileges_permanently() != 0){

2122

1594

perror_plus("Failed to raise privileges");

2123

1595

_exit(EX_NOPERM);

2124

1596

}

2136

1608

perror_plus("setgroups");

2137

1609

_exit(EX_NOPERM);

2138

1610

}

1611

ret = dup2(devnull, STDIN_FILENO);

1612

if(ret == -1){

1613

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

1614

_exit(EX_OSERR);

1615

}

1616

ret = close(devnull);

1617

if(ret == -1){

1618

perror_plus("close");

1619

_exit(EX_OSERR);

1620

}

1621

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1622

if(ret == -1){

1623

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

1624

_exit(EX_OSERR);

1625

}

2139

1626

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

2140

1627

if(ret == -1){

2141

1628

perror_plus("setenv");

2176

1663

_exit(EX_OSERR);

2177

1664

}

2178

1665

}

2179

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

2180

direntry->d_name,

2181

O_RDONLY));

2182

if(hook_fd == -1){

2183

perror_plus("openat");

2184

_exit(EXIT_FAILURE);

2185

}

2186

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

2187

perror_plus("close");

2188

_exit(EXIT_FAILURE);

2189

}

2190

ret = dup2(devnull, STDIN_FILENO);

2191

if(ret == -1){

2192

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

2193

_exit(EX_OSERR);

2194

}

2195

ret = close(devnull);

2196

if(ret == -1){

2197

perror_plus("close");

2198

_exit(EX_OSERR);

2199

}

2200

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2201

if(ret == -1){

2202

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

2203

_exit(EX_OSERR);

2204

}

2205

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

2206

environ) == -1){

1666

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

1667

{ direntry->d_name, NULL }, environ) == -1){

2207

1668

perror_plus("fexecve");

2208

1669

_exit(EXIT_FAILURE);

2209

1670

}

2210

1671

} else {

2211

if(hook_pid == -1){

2212

perror_plus("fork");

2213

free(direntry);

2214

continue;

2215

}

2216

1672

int status;

2217

1673

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

2218

1674

perror_plus("waitpid");

2219

free(direntry);

2220

1675

continue;

2221

1676

}

2222

1677

if(WIFEXITED(status)){

2224

1679

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

2225

1680

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

2226

1681

WEXITSTATUS(status));

2227

free(direntry);

2228

1682

continue;

2229

1683

}

2230

1684

} else if(WIFSIGNALED(status)){

2231

1685

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

2232

1686

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

2233

1687

WTERMSIG(status));

2234

free(direntry);

2235

1688

continue;

2236

1689

} else {

2237

1690

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

2238

1691

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

2239

free(direntry);

2240

1692

continue;

2241

1693

}

2242

1694

}

2244

1696

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

2245

1697

direntry->d_name);

2246

1698

}

2247

free(direntry);

2248

1699

}

2249

free(direntries);

2250

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

1700

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

2251

1701

perror_plus("close");

2252

1702

} else {

2253

1703

hookdir_fd = -1;

2256

1706

}

2257

1707

2258

1708

__attribute__((nonnull, warn_unused_result))

2259

int bring_up_interface(const char *const interface,

2260

const float delay){

2261

int old_errno = errno;

1709

error_t bring_up_interface(const char *const interface,

1710

const float delay){

1711

error_t old_errno = errno;

2262

1712

int ret;

2263

1713

struct ifreq network;

2264

1714

unsigned int if_index = if_nametoindex(interface);

2274

1724

}

2275

1725

2276

1726

if(not interface_is_up(interface)){

2277

int ret_errno = 0;

2278

int ioctl_errno = 0;

1727

error_t ret_errno = 0, ioctl_errno = 0;

2279

1728

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

2280

1729

ret_errno = errno;

2281

1730

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

2294

1743

}

2295

1744

2296

1745

if(quit_now){

2297

ret = close(sd);

1746

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

2298

1747

if(ret == -1){

2299

1748

perror_plus("close");

2300

1749

}

2310

1759

/* Raise privileges */

2311

1760

ret_errno = raise_privileges();

2312

1761

if(ret_errno != 0){

2313

errno = ret_errno;

2314

1762

perror_plus("Failed to raise privileges");

2315

1763

}

2316

1764

2350

1798

}

2351

1799

2352

1800

/* Close the socket */

2353

ret = close(sd);

1801

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

2354

1802

if(ret == -1){

2355

1803

perror_plus("close");

2356

1804

}

2368

1816

2369

1817

/* Sleep checking until interface is running.

2370

1818

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

2371

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

1819

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

2372

1820

if(interface_is_running(interface)){

2373

1821

break;

2374

1822

}

2384

1832

}

2385

1833

2386

1834

__attribute__((nonnull, warn_unused_result))

2387

int take_down_interface(const char *const interface){

2388

int old_errno = errno;

1835

error_t take_down_interface(const char *const interface){

1836

error_t old_errno = errno;

2389

1837

struct ifreq network;

2390

1838

unsigned int if_index = if_nametoindex(interface);

2391

1839

if(if_index == 0){

2394

1842

return ENXIO;

2395

1843

}

2396

1844

if(interface_is_up(interface)){

2397

int ret_errno = 0;

2398

int ioctl_errno = 0;

1845

error_t ret_errno = 0, ioctl_errno = 0;

2399

1846

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

2400

1847

ret_errno = errno;

2401

1848

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

2421

1868

/* Raise privileges */

2422

1869

ret_errno = raise_privileges();

2423

1870

if(ret_errno != 0){

2424

errno = ret_errno;

2425

1871

perror_plus("Failed to raise privileges");

2426

1872

}

2427

1873

2439

1885

}

2440

1886

2441

1887

/* Close the socket */

2442

int ret = close(sd);

1888

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

2443

1889

if(ret == -1){

2444

1890

perror_plus("close");

2445

1891

}

2460

1906

}

2461

1907

2462

1908

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

2463

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

2464

#if GNUTLS_VERSION_NUMBER >= 0x030606

2465

.priority = "SECURE128:!CTYPE-X.509"

2466

":+CTYPE-RAWPK:!RSA:!VERS-ALL:+VERS-TLS1.3"

2467

":%PROFILE_ULTRA",

2468

#elif GNUTLS_VERSION_NUMBER < 0x030600

2469

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

2470

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

2471

#else

2472

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

2473

#endif

2474

.current_server = NULL, .interfaces = NULL,

2475

.interfaces_size = 0 };

1909

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

1910

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

1911

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

1912

.interfaces = NULL, .interfaces_size = 0 };

2476

1913

AvahiSServiceBrowser *sb = NULL;

2477

1914

error_t ret_errno;

2478

1915

int ret;

2487

1924

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2488

1925

const char *seckey = PATHDIR "/" SECKEY;

2489

1926

const char *pubkey = PATHDIR "/" PUBKEY;

2490

#if GNUTLS_VERSION_NUMBER >= 0x030606

2491

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2492

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2493

#endif

2494

const char *dh_params_file = NULL;

2495

1927

char *interfaces_hooks = NULL;

2496

1928

2497

1929

bool gnutls_initialized = false;

2544

1976

{ .name = "pubkey", .key = 'p',

2545

1977

.arg = "FILE",

2546

1978

.doc = "OpenPGP public key file base name",

2547

.group = 1 },

2548

{ .name = "tls-privkey", .key = 't',

2549

.arg = "FILE",

2550

#if GNUTLS_VERSION_NUMBER >= 0x030606

2551

.doc = "TLS private key file base name",

2552

#else

2553

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2554

#endif

2555

.group = 1 },

2556

{ .name = "tls-pubkey", .key = 'T',

2557

.arg = "FILE",

2558

#if GNUTLS_VERSION_NUMBER >= 0x030606

2559

.doc = "TLS public key file base name",

2560

#else

2561

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2562

#endif

2563

.group = 1 },

1979

.group = 2 },

2564

1980

{ .name = "dh-bits", .key = 129,

2565

1981

.arg = "BITS",

2566

1982

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

2567

1983

" Diffie-Hellman key exchange",

2568

1984

.group = 2 },

2569

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

2570

.arg = "FILE",

2571

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

2572

" for the Diffie-Hellman key exchange",

2573

.group = 2 },

2574

1985

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

2575

1986

.arg = "STRING",

2576

1987

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

2622

2033

case 'p': /* --pubkey */

2623

2034

pubkey = arg;

2624

2035

break;

2625

case 't': /* --tls-privkey */

2626

#if GNUTLS_VERSION_NUMBER >= 0x030606

2627

tls_privkey = arg;

2628

#endif

2629

break;

2630

case 'T': /* --tls-pubkey */

2631

#if GNUTLS_VERSION_NUMBER >= 0x030606

2632

tls_pubkey = arg;

2633

#endif

2634

break;

2635

2036

case 129: /* --dh-bits */

2636

2037

errno = 0;

2637

2038

tmpmax = strtoimax(arg, &tmp, 10);

2641

2042

}

2642

2043

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

2643

2044

break;

2644

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

2645

dh_params_file = arg;

2646

break;

2647

2045

case 130: /* --priority */

2648

2046

mc.priority = arg;

2649

2047

break;

2689

2087

.args_doc = "",

2690

2088

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

2691

2089

" passwords from a Mandos server" };

2692

ret_errno = argp_parse(&argp, argc, argv,

2693

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2694

switch(ret_errno){

2090

ret = argp_parse(&argp, argc, argv,

2091

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2092

switch(ret){

2695

2093

case 0:

2696

2094

break;

2697

2095

case ENOMEM:

2698

2096

default:

2699

errno = ret_errno;

2097

errno = ret;

2700

2098

perror_plus("argp_parse");

2701

2099

exitcode = EX_OSERR;

2702

2100

goto end;

2705

2103

goto end;

2706

2104

}

2707

2105

}

2708

2106

2709

2107

{

2710

2108

/* Work around Debian bug #633582:

2711

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

2109

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

2712

2110

2713

2111

/* Re-raise privileges */

2714

ret = raise_privileges();

2715

if(ret != 0){

2716

errno = ret;

2112

ret_errno = raise_privileges();

2113

if(ret_errno != 0){

2114

errno = ret_errno;

2717

2115

perror_plus("Failed to raise privileges");

2718

2116

} else {

2719

2117

struct stat st;

2735

2133

}

2736

2134

}

2737

2135

}

2738

close(seckey_fd);

2136

TEMP_FAILURE_RETRY(close(seckey_fd));

2739

2137

}

2740

2138

}

2741

2139

2742

2140

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

2743

2141

int pubkey_fd = open(pubkey, O_RDONLY);

2744

2142

if(pubkey_fd == -1){

2756

2154

}

2757

2155

}

2758

2156

}

2759

close(pubkey_fd);

2760

}

2761

}

2762

2763

if(dh_params_file != NULL

2764

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

2765

int dhparams_fd = open(dh_params_file, O_RDONLY);

2766

if(dhparams_fd == -1){

2767

perror_plus("open");

2768

} else {

2769

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

2770

if(ret == -1){

2771

perror_plus("fstat");

2772

} else {

2773

if(S_ISREG(st.st_mode)

2774

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

2775

ret = fchown(dhparams_fd, uid, gid);

2776

if(ret == -1){

2777

perror_plus("fchown");

2778

}

2779

}

2780

}

2781

close(dhparams_fd);

2782

}

2783

}

2784

2157

TEMP_FAILURE_RETRY(close(pubkey_fd));

2158

}

2159

}

2160

2785

2161

/* Lower privileges */

2786

ret = lower_privileges();

2787

if(ret != 0){

2788

errno = ret;

2162

ret_errno = lower_privileges();

2163

if(ret_errno != 0){

2164

errno = ret_errno;

2789

2165

perror_plus("Failed to lower privileges");

2790

2166

}

2791

2167

}

2904

2280

2905

2281

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

2906

2282

if(mc.interfaces == NULL){

2907

struct dirent **direntries = NULL;

2283

struct dirent **direntries;

2908

2284

/* Look for any good interfaces */

2909

2285

ret = scandir(sys_class_net, &direntries, good_interface,

2910

2286

alphasort);

2916

2292

if(ret_errno != 0){

2917

2293

errno = ret_errno;

2918

2294

perror_plus("argz_add");

2919

free(direntries[i]);

2920

2295

continue;

2921

2296

}

2922

2297

if(debug){

2923

2298

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

2924

2299

direntries[i]->d_name);

2925

2300

}

2926

free(direntries[i]);

2927

2301

}

2928

2302

free(direntries);

2929

2303

} else {

2930

if(ret == 0){

2931

free(direntries);

2932

}

2304

free(direntries);

2933

2305

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

2934

2306

exitcode = EXIT_FAILURE;

2935

2307

goto end;

2961

2333

errno = bring_up_interface(interface, delay);

2962

2334

if(not interface_was_up){

2963

2335

if(errno != 0){

2964

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

2965

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

2336

perror_plus("Failed to bring up interface");

2966

2337

} else {

2967

2338

errno = argz_add(&interfaces_to_take_down,

2968

2339

&interfaces_to_take_down_size,

2991

2362

goto end;

2992

2363

}

2993

2364

2994

#if GNUTLS_VERSION_NUMBER >= 0x030606

2995

ret = init_gnutls_global(tls_pubkey, tls_privkey, dh_params_file, &mc);

2996

#elif GNUTLS_VERSION_NUMBER < 0x030600

2997

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

2998

#else

2999

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

3000

#endif

2365

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

3001

2366

if(ret == -1){

3002

2367

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

3003

2368

exitcode = EX_UNAVAILABLE;

3125

2490

3126

2491

/* Allocate a new server */

3127

2492

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3128

&config, NULL, NULL, &ret);

2493

&config, NULL, NULL, &ret_errno);

3129

2494

3130

2495

/* Free the Avahi configuration data */

3131

2496

avahi_server_config_free(&config);

3134

2499

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

3135

2500

if(mc.server == NULL){

3136

2501

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

3137

avahi_strerror(ret));

2502

avahi_strerror(ret_errno));

3138

2503

exitcode = EX_UNAVAILABLE;

3139

2504

goto end;

3140

2505

}

3175

2540

end:

3176

2541

3177

2542

if(debug){

3178

if(signal_received){

3179

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

3180

argv[0], signal_received,

3181

strsignal(signal_received));

3182

} else {

3183

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

3184

}

2543

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

3185

2544

}

3186

2545

3187

2546

/* Cleanup things */

3198

2557

3199

2558

if(gnutls_initialized){

3200

2559

gnutls_certificate_free_credentials(mc.cred);

2560

gnutls_global_deinit();

3201

2561

gnutls_dh_params_deinit(mc.dh_params);

3202

2562

}

3203

2563

3211

2571

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

3212

2572

while(mc.current_server != NULL){

3213

2573

server *next = mc.current_server->next;

3214

#ifdef __GNUC__

3215

#pragma GCC diagnostic push

3216

#pragma GCC diagnostic ignored "-Wcast-qual"

3217

#endif

3218

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

3219

#ifdef __GNUC__

3220

#pragma GCC diagnostic pop

3221

#endif

3222

2574

free(mc.current_server);

3223

2575

mc.current_server = next;

3224

2576

}

3226

2578

3227

2579

/* Re-raise privileges */

3228

2580

{

3229

ret = raise_privileges();

3230

if(ret != 0){

3231

errno = ret;

2581

ret_errno = raise_privileges();

2582

if(ret_errno != 0){

3232

2583

perror_plus("Failed to raise privileges");

3233

2584

} else {

3234

2585

3239

2590

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

3240

2591

{

3241

2592

char *interface = NULL;

3242

while((interface = argz_next(interfaces_to_take_down,

3243

interfaces_to_take_down_size,

3244

interface))){

3245

ret = take_down_interface(interface);

3246

if(ret != 0){

3247

errno = ret;

2593

while((interface=argz_next(interfaces_to_take_down,

2594

interfaces_to_take_down_size,

2595

interface))){

2596

ret_errno = take_down_interface(interface);

2597

if(ret_errno != 0){

2598

errno = ret_errno;

3248

2599

perror_plus("Failed to take down interface");

3249

2600

}

3250

2601

}

3255

2606

}

3256

2607

}

3257

2608

3258

ret = lower_privileges_permanently();

3259

if(ret != 0){

3260

errno = ret;

2609

ret_errno = lower_privileges_permanently();

2610

if(ret_errno != 0){

3261

2611

perror_plus("Failed to lower privileges permanently");

3262

2612

}

3263

2613

}

3265

2615

free(interfaces_to_take_down);

3266

2616

free(interfaces_hooks);

3267

2617

3268

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

3269

uintmax_t level){

3270

struct dirent **direntries = NULL;

3271

int dret;

3272

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

3273

O_RDONLY

3274

| O_NOFOLLOW

3275

| O_DIRECTORY

3276

| O_PATH));

3277

if(dir_fd == -1){

3278

perror_plus("open");

3279

return;

3280

}

3281

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

3282

notdotentries, alphasort);

3283

if(numentries >= 0){

3284

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

3285

if(debug){

3286

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

3287

dirname, direntries[i]->d_name);

3288

}

3289

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

3290

if(dret == -1){

3291

if(errno == EISDIR){

3292

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

3293

AT_REMOVEDIR);

3294

}

3295

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

3296

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

3297

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

3298

/* Recurse only in this special case */

3299

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

3300

dret = 0;

3301

}

3302

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

3303

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

3304

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

3305

}

3306

}

3307

free(direntries[i]);

3308

}

3309

3310

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

3311

free(direntries);

3312

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3313

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

3314

perror_plus("rmdir");

3315

}

3316

} else {

3317

perror_plus("scandirat");

3318

}

3319

close(dir_fd);

3320

}

3321

3322

2618

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

3323

2619

if(tempdir != NULL){

3324

clean_dir_at(-1, tempdir, 0);

2620

struct dirent **direntries = NULL;

2621

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY));

2622

if(tempdir_fd == -1){

2623

perror_plus("open");

2624

} else {

2625

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

2626

alphasort);

2627

if(numentries > 0){

2628

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

2629

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2630

if(ret == -1){

2631

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2632

" \"%s\", 0): %s\n", tempdir,

2633

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

2634

}

2635

}

2636

2637

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

2638

free(direntries);

2639

if(numentries == -1){

2640

perror_plus("scandir");

2641

}

2642

ret = rmdir(tempdir);

2643

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

2644

perror_plus("rmdir");

2645

}

2646

}

2647

TEMP_FAILURE_RETRY(close(tempdir_fd));

2648

}

3325

2649

}

3326

2650

3327

2651

if(quit_now){