/mandos/trunk : revision 717

9

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

10

*

11

* Everything else is

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13

14

*

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* 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

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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

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

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*

20

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

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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

*

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* 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

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

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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() */

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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;

280

266

return true;

281

267

}

282

268

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

269

/*

336

270

* Initialize GPGME.

337

271

*/

357

291

return false;

358

292

}

359

293

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

294

rc = gpgme_data_new_from_fd(&pgp_data, fd);

411

295

if(rc != GPG_ERR_NO_ERROR){

412

296

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

420

304

gpgme_strsource(rc), gpgme_strerror(rc));

421

305

return false;

422

306

}

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

307

499

ret = close(fd);

308

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

500

309

if(ret == -1){

501

310

perror_plus("close");

502

311

}

541

350

/* Create new GPGME "context" */

542

351

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

543

352

if(rc != GPG_ERR_NO_ERROR){

544

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

545

gpgme_strsource(rc), gpgme_strerror(rc));

353

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

354

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

355

gpgme_strerror(rc));

546

356

return false;

547

357

}

548

358

584

394

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

585

395

rc = gpgme_data_new(&dh_plain);

586

396

if(rc != GPG_ERR_NO_ERROR){

587

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

397

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

398

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

588

399

gpgme_strsource(rc), gpgme_strerror(rc));

589

400

gpgme_data_release(dh_crypto);

590

401

return -1;

603

414

if(result == NULL){

604

415

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

605

416

} 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");

417

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

418

result->unsupported_algorithm);

419

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

420

result->wrong_key_usage);

612

421

if(result->file_name != NULL){

613

422

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

614

423

}

615

616

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

617

r = r->next){

424

gpgme_recipient_t recipient;

425

recipient = result->recipients;

426

while(recipient != NULL){

618

427

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);

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

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

621

431

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

622

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

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "No" : "Yes");

434

recipient = recipient->next;

623

435

}

624

436

}

625

437

}

681

493

return plaintext_length;

682

494

}

683

495

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

496

__attribute__((warn_unused_result))

692

497

static const char *safer_gnutls_strerror(int value){

693

498

const char *ret = gnutls_strerror(value);

694

return safe_string(ret);

499

if(ret == NULL)

500

ret = "(unknown)";

501

return ret;

695

502

}

696

503

697

504

/* GnuTLS log function callback */

701

508

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

702

509

}

703

510

704

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

511

__attribute__((nonnull, warn_unused_result))

705

512

static int init_gnutls_global(const char *pubkeyfilename,

706

513

const char *seckeyfilename,

707

const char *dhparamsfilename,

708

514

mandos_context *mc){

709

515

int ret;

710

516

712

518

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

713

519

}

714

520

521

ret = gnutls_global_init();

522

if(ret != GNUTLS_E_SUCCESS){

523

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

524

safer_gnutls_strerror(ret));

525

return -1;

526

}

527

715

528

if(debug){

716

529

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

717

530

* - GnuTLS manual

725

538

if(ret != GNUTLS_E_SUCCESS){

726

539

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

727

540

safer_gnutls_strerror(ret));

541

gnutls_global_deinit();

728

542

return -1;

729

543

}

730

544

731

545

if(debug){

732

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

733

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

546

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

547

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

734

548

pubkeyfilename,

735

549

seckeyfilename);

736

550

}

737

551

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

552

ret = gnutls_certificate_set_openpgp_key_file

752

553

(mc->cred, pubkeyfilename, seckeyfilename,

753

554

GNUTLS_OPENPGP_FMT_BASE64);

754

#else

755

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

756

#endif

757

555

if(ret != GNUTLS_E_SUCCESS){

758

556

fprintf_plus(stderr,

759

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

557

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

760

558

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

761

559

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

762

560

safer_gnutls_strerror(ret));

771

569

safer_gnutls_strerror(ret));

772

570

goto globalfail;

773

571

}

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

}

572

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

573

if(ret != GNUTLS_E_SUCCESS){

574

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

575

safer_gnutls_strerror(ret));

576

goto globalfail;

577

}

578

579

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

956

580

957

581

return 0;

958

582

959

583

globalfail:

960

584

961

585

gnutls_certificate_free_credentials(mc->cred);

586

gnutls_global_deinit();

962

587

gnutls_dh_params_deinit(mc->dh_params);

963

588

return -1;

964

589

}

969

594

int ret;

970

595

/* GnuTLS session creation */

971

596

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

));

597

ret = gnutls_init(session, GNUTLS_SERVER);

980

598

if(quit_now){

981

599

return -1;

982

600

}

1023

641

/* ignore client certificate if any. */

1024

642

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

1025

643

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

645

1026

646

return 0;

1027

647

}

1028

648

1030

650

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

1031

651

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

1032

652

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

653

/* Called when a Mandos server is found */

1200

654

__attribute__((nonnull, warn_unused_result))

1201

655

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

1212

666

int retval = -1;

1213

667

gnutls_session_t session;

1214

668

int pf; /* Protocol family */

1215

bool route_added = false;

1216

669

1217

670

errno = 0;

1218

671

1240

693

bool match = false;

1241

694

{

1242

695

char *interface = NULL;

1243

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

1244

mc->interfaces_size,

1245

interface))){

696

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

697

interface))){

1246

698

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

1247

699

match = true;

1248

700

break;

1277

729

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

1278

730

}

1279

731

1280

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

732

tcp_sd = socket(pf, SOCK_STREAM, 0);

1281

733

if(tcp_sd < 0){

1282

734

int e = errno;

1283

735

perror_plus("socket");

1290

742

goto mandos_end;

1291

743

}

1292

744

745

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

1293

746

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);

747

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

748

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

1297

749

} 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);

750

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

751

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

1301

752

}

1302

753

if(ret < 0 ){

1303

754

int e = errno;

1373

824

goto mandos_end;

1374

825

}

1375

826

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;

827

if(af == AF_INET6){

828

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

829

sizeof(struct sockaddr_in6));

830

} else {

831

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

832

sizeof(struct sockaddr_in));

833

}

834

if(ret < 0){

835

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

836

int e = errno;

837

perror_plus("connect");

838

errno = e;

839

}

840

goto mandos_end;

841

}

842

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

1431

846

}

1432

847

1433

848

const char *out = mandos_protocol_version;

1587

1002

&decrypted_buffer, mc);

1588

1003

if(decrypted_buffer_size >= 0){

1589

1004

1590

clearerr(stdout);

1591

1005

written = 0;

1592

1006

while(written < (size_t) decrypted_buffer_size){

1593

1007

if(quit_now){

1609

1023

}

1610

1024

written += (size_t)ret;

1611

1025

}

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

1026

retval = 0;

1623

1027

}

1624

1028

}

1627

1031

1628

1032

mandos_end:

1629

1033

{

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

1034

int e = errno;

1637

1035

free(decrypted_buffer);

1638

1036

free(buffer);

1639

1037

if(tcp_sd >= 0){

1640

ret = close(tcp_sd);

1038

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

1641

1039

}

1642

1040

if(ret == -1){

1643

1041

if(e == 0){

1655

1053

return retval;

1656

1054

}

1657

1055

1056

__attribute__((nonnull))

1658

1057

static void resolve_callback(AvahiSServiceResolver *r,

1659

1058

AvahiIfIndex interface,

1660

1059

AvahiProtocol proto,

1797

1196

__attribute__((nonnull, warn_unused_result))

1798

1197

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

1799

1198

int ret;

1800

int old_errno;

1199

error_t ret_errno;

1801

1200

1802

1201

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

1803

1202

if(s < 0){

1804

old_errno = errno;

1203

ret_errno = errno;

1805

1204

perror_plus("socket");

1806

errno = old_errno;

1205

errno = ret_errno;

1807

1206

return false;

1808

1207

}

1809

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

1810

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

1208

strcpy(ifr->ifr_name, ifname);

1811

1209

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1812

1210

if(ret == -1){

1813

1211

if(debug){

1814

old_errno = errno;

1212

ret_errno = errno;

1815

1213

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;

1214

errno = ret_errno;

1822

1215

}

1823

1216

return false;

1824

1217

}

1825

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

1826

old_errno = errno;

1827

perror_plus("close");

1828

errno = old_errno;

1829

}

1830

1218

return true;

1831

1219

}

1832

1220

2074

1462

}

2075

1463

}

2076

1464

1465

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

1466

__attribute__((warn_unused_result))

1467

error_t raise_privileges(void){

1468

error_t old_errno = errno;

1469

error_t ret_errno = 0;

1470

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

1471

ret_errno = errno;

1472

}

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

1477

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

1478

__attribute__((warn_unused_result))

1479

error_t raise_privileges_permanently(void){

1480

error_t old_errno = errno;

1481

error_t ret_errno = raise_privileges();

1482

if(ret_errno != 0){

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

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

1487

ret_errno = errno;

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

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

1494

__attribute__((warn_unused_result))

1495

error_t lower_privileges(void){

1496

error_t old_errno = errno;

1497

error_t ret_errno = 0;

1498

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

1499

ret_errno = errno;

1500

}

1501

errno = old_errno;

1502

return ret_errno;

1503

}

1504

1505

/* Lower privileges permanently */

1506

__attribute__((warn_unused_result))

1507

error_t lower_privileges_permanently(void){

1508

error_t old_errno = errno;

1509

error_t ret_errno = 0;

1510

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

1511

ret_errno = errno;

1512

}

1513

errno = old_errno;

1514

return ret_errno;

1515

}

1516

2077

1517

__attribute__((nonnull))

2078

1518

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

2079

1519

const float delay){

2080

1520

struct dirent **direntries = NULL;

2081

1521

if(hookdir_fd == -1){

2082

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2083

| O_CLOEXEC);

1522

hookdir_fd = open(hookdir, O_RDONLY);

2084

1523

if(hookdir_fd == -1){

2085

1524

if(errno == ENOENT){

2086

1525

if(debug){

2093

1532

return;

2094

1533

}

2095

1534

}

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

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

2101

1537

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

2102

1538

runnable_hook, alphasort);

1539

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

1540

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

1541

alphasort);

1542

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

1543

#else /* not __GLIBC__ */

1544

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

1545

alphasort);

1546

#endif /* not __GLIBC__ */

2103

1547

if(numhooks == -1){

2104

1548

perror_plus("scandir");

2105

close(devnull);

2106

1549

return;

2107

1550

}

2108

1551

struct dirent *direntry;

2109

1552

int ret;

1553

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

2110

1554

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

2111

1555

direntry = direntries[i];

2112

1556

if(debug){

2136

1580

perror_plus("setgroups");

2137

1581

_exit(EX_NOPERM);

2138

1582

}

1583

ret = dup2(devnull, STDIN_FILENO);

1584

if(ret == -1){

1585

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

1586

_exit(EX_OSERR);

1587

}

1588

ret = close(devnull);

1589

if(ret == -1){

1590

perror_plus("close");

1591

_exit(EX_OSERR);

1592

}

1593

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1594

if(ret == -1){

1595

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

1596

_exit(EX_OSERR);

1597

}

2139

1598

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

2140

1599

if(ret == -1){

2141

1600

perror_plus("setenv");

2176

1635

_exit(EX_OSERR);

2177

1636

}

2178

1637

}

2179

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

2180

direntry->d_name,

2181

O_RDONLY));

1638

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

2182

1639

if(hook_fd == -1){

2183

1640

perror_plus("openat");

2184

1641

_exit(EXIT_FAILURE);

2185

1642

}

2186

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

1643

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

2187

1644

perror_plus("close");

2188

1645

_exit(EXIT_FAILURE);

2189

1646

}

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

1647

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

2206

1648

environ) == -1){

2207

1649

perror_plus("fexecve");

2208

1650

_exit(EXIT_FAILURE);

2209

1651

}

2210

1652

} else {

2211

if(hook_pid == -1){

2212

perror_plus("fork");

2213

free(direntry);

2214

continue;

2215

}

2216

1653

int status;

2217

1654

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

2218

1655

perror_plus("waitpid");

2247

1684

free(direntry);

2248

1685

}

2249

1686

free(direntries);

2250

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

1687

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

2251

1688

perror_plus("close");

2252

1689

} else {

2253

1690

hookdir_fd = -1;

2256

1693

}

2257

1694

2258

1695

__attribute__((nonnull, warn_unused_result))

2259

int bring_up_interface(const char *const interface,

2260

const float delay){

2261

int old_errno = errno;

1696

error_t bring_up_interface(const char *const interface,

1697

const float delay){

1698

error_t old_errno = errno;

2262

1699

int ret;

2263

1700

struct ifreq network;

2264

1701

unsigned int if_index = if_nametoindex(interface);

2274

1711

}

2275

1712

2276

1713

if(not interface_is_up(interface)){

2277

int ret_errno = 0;

2278

int ioctl_errno = 0;

1714

error_t ret_errno = 0, ioctl_errno = 0;

2279

1715

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

2280

1716

ret_errno = errno;

2281

1717

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

2294

1730

}

2295

1731

2296

1732

if(quit_now){

2297

ret = close(sd);

1733

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

2298

1734

if(ret == -1){

2299

1735

perror_plus("close");

2300

1736

}

2350

1786

}

2351

1787

2352

1788

/* Close the socket */

2353

ret = close(sd);

1789

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

2354

1790

if(ret == -1){

2355

1791

perror_plus("close");

2356

1792

}

2368

1804

2369

1805

/* Sleep checking until interface is running.

2370

1806

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

2371

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

1807

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

2372

1808

if(interface_is_running(interface)){

2373

1809

break;

2374

1810

}

2384

1820

}

2385

1821

2386

1822

__attribute__((nonnull, warn_unused_result))

2387

int take_down_interface(const char *const interface){

2388

int old_errno = errno;

1823

error_t take_down_interface(const char *const interface){

1824

error_t old_errno = errno;

2389

1825

struct ifreq network;

2390

1826

unsigned int if_index = if_nametoindex(interface);

2391

1827

if(if_index == 0){

2394

1830

return ENXIO;

2395

1831

}

2396

1832

if(interface_is_up(interface)){

2397

int ret_errno = 0;

2398

int ioctl_errno = 0;

1833

error_t ret_errno = 0, ioctl_errno = 0;

2399

1834

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

2400

1835

ret_errno = errno;

2401

1836

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

2439

1874

}

2440

1875

2441

1876

/* Close the socket */

2442

int ret = close(sd);

1877

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

2443

1878

if(ret == -1){

2444

1879

perror_plus("close");

2445

1880

}

2460

1895

}

2461

1896

2462

1897

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 };

1898

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

1899

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

1900

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

1901

.interfaces = NULL, .interfaces_size = 0 };

2476

1902

AvahiSServiceBrowser *sb = NULL;

2477

1903

error_t ret_errno;

2478

1904

int ret;

2487

1913

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2488

1914

const char *seckey = PATHDIR "/" SECKEY;

2489

1915

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

1916

char *interfaces_hooks = NULL;

2496

1917

2497

1918

bool gnutls_initialized = false;

2544

1965

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

2545

1966

.arg = "FILE",

2546

1967

.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 },

1968

.group = 2 },

2564

1969

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

2565

1970

.arg = "BITS",

2566

1971

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

2567

1972

" Diffie-Hellman key exchange",

2568

1973

.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

1974

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

2575

1975

.arg = "STRING",

2576

1976

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

2622

2022

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

2623

2023

pubkey = arg;

2624

2024

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

2025

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

2636

2026

errno = 0;

2637

2027

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

2641

2031

}

2642

2032

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

2643

2033

break;

2644

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

2645

dh_params_file = arg;

2646

break;

2647

2034

case 130: /* --priority */

2648

2035

mc.priority = arg;

2649

2036

break;

2689

2076

.args_doc = "",

2690

2077

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

2691

2078

" 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){

2079

ret = argp_parse(&argp, argc, argv,

2080

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2081

switch(ret){

2695

2082

case 0:

2696

2083

break;

2697

2084

case ENOMEM:

2698

2085

default:

2699

errno = ret_errno;

2086

errno = ret;

2700

2087

perror_plus("argp_parse");

2701

2088

exitcode = EX_OSERR;

2702

2089

goto end;

2705

2092

goto end;

2706

2093

}

2707

2094

}

2708

2095

2709

2096

{

2710

2097

/* Work around Debian bug #633582:

2711

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

2098

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

2712

2099

2713

2100

/* Re-raise privileges */

2714

ret = raise_privileges();

2715

if(ret != 0){

2716

errno = ret;

2101

ret_errno = raise_privileges();

2102

if(ret_errno != 0){

2103

errno = ret_errno;

2717

2104

perror_plus("Failed to raise privileges");

2718

2105

} else {

2719

2106

struct stat st;

2735

2122

}

2736

2123

}

2737

2124

}

2738

close(seckey_fd);

2125

TEMP_FAILURE_RETRY(close(seckey_fd));

2739

2126

}

2740

2127

}

2741

2128

2742

2129

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

2743

2130

int pubkey_fd = open(pubkey, O_RDONLY);

2744

2131

if(pubkey_fd == -1){

2756

2143

}

2757

2144

}

2758

2145

}

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

2146

TEMP_FAILURE_RETRY(close(pubkey_fd));

2147

}

2148

}

2149

2785

2150

/* Lower privileges */

2786

ret = lower_privileges();

2787

if(ret != 0){

2788

errno = ret;

2151

ret_errno = lower_privileges();

2152

if(ret_errno != 0){

2153

errno = ret_errno;

2789

2154

perror_plus("Failed to lower privileges");

2790

2155

}

2791

2156

}

2961

2326

errno = bring_up_interface(interface, delay);

2962

2327

if(not interface_was_up){

2963

2328

if(errno != 0){

2964

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

2965

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

2329

perror_plus("Failed to bring up interface");

2966

2330

} else {

2967

2331

errno = argz_add(&interfaces_to_take_down,

2968

2332

&interfaces_to_take_down_size,

2991

2355

goto end;

2992

2356

}

2993

2357

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

2358

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

3001

2359

if(ret == -1){

3002

2360

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

3003

2361

exitcode = EX_UNAVAILABLE;

3125

2483

3126

2484

/* Allocate a new server */

3127

2485

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3128

&config, NULL, NULL, &ret);

2486

&config, NULL, NULL, &ret_errno);

3129

2487

3130

2488

/* Free the Avahi configuration data */

3131

2489

avahi_server_config_free(&config);

3134

2492

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

3135

2493

if(mc.server == NULL){

3136

2494

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

3137

avahi_strerror(ret));

2495

avahi_strerror(ret_errno));

3138

2496

exitcode = EX_UNAVAILABLE;

3139

2497

goto end;

3140

2498

}

3175

2533

end:

3176

2534

3177

2535

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

}

2536

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

3185

2537

}

3186

2538

3187

2539

/* Cleanup things */

3198

2550

3199

2551

if(gnutls_initialized){

3200

2552

gnutls_certificate_free_credentials(mc.cred);

2553

gnutls_global_deinit();

3201

2554

gnutls_dh_params_deinit(mc.dh_params);

3202

2555

}

3203

2556

3226

2579

3227

2580

/* Re-raise privileges */

3228

2581

{

3229

ret = raise_privileges();

3230

if(ret != 0){

3231

errno = ret;

2582

ret_errno = raise_privileges();

2583

if(ret_errno != 0){

2584

errno = ret_errno;

3232

2585

perror_plus("Failed to raise privileges");

3233

2586

} else {

3234

2587

3239

2592

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

3240

2593

{

3241

2594

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;

2595

while((interface=argz_next(interfaces_to_take_down,

2596

interfaces_to_take_down_size,

2597

interface))){

2598

ret_errno = take_down_interface(interface);

2599

if(ret_errno != 0){

2600

errno = ret_errno;

3248

2601

perror_plus("Failed to take down interface");

3249

2602

}

3250

2603

}

3255

2608

}

3256

2609

}

3257

2610

3258

ret = lower_privileges_permanently();

3259

if(ret != 0){

3260

errno = ret;

2611

ret_errno = lower_privileges_permanently();

2612

if(ret_errno != 0){

2613

errno = ret_errno;

3261

2614

perror_plus("Failed to lower privileges permanently");

3262

2615

}

3263

2616

}

3265

2618

free(interfaces_to_take_down);

3266

2619

free(interfaces_hooks);

3267

2620

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

2621

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

3323

2622

if(tempdir != NULL){

3324

clean_dir_at(-1, tempdir, 0);

2623

struct dirent **direntries = NULL;

2624

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

2625

O_NOFOLLOW));

2626

if(tempdir_fd == -1){

2627

perror_plus("open");

2628

} else {

2629

#ifdef __GLIBC__

2630

#if __GLIBC_PREREQ(2, 15)

2631

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

2632

notdotentries, alphasort);

2633

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

2634

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

2635

alphasort);

2636

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

2637

#else /* not __GLIBC__ */

2638

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

2639

alphasort);

2640

#endif /* not __GLIBC__ */

2641

if(numentries >= 0){

2642

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

2643

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

2644

if(ret == -1){

2645

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

2646

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

2647

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

2648

}

2649

free(direntries[i]);

2650

}

2651

2652

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

2653

free(direntries);

2654

if(numentries == -1){

2655

perror_plus("scandir");

2656

}

2657

ret = rmdir(tempdir);

2658

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

2659

perror_plus("rmdir");

2660

}

2661

}

2662

TEMP_FAILURE_RETRY(close(tempdir_fd));

2663

}

3325

2664

}

3326

2665

3327

2666

if(quit_now){