/mandos/trunk : revision 1108

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

10

*

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* Everything else is

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*

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

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

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

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

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*

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

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13

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*

15

* This file is part of Mandos.

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*

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

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

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

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* (at your option) any later version.

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*

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

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* WITHOUT ANY WARRANTY; without even the implied warranty of

22

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

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25

* General Public License for more details.

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26

*

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27

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

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* along with this program. If not, see

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

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

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29

*

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

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31

*/

46

47

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

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48

strtof(), abort() */

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

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

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

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

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asprintf(), strncpy(), strsignal()

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*/

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53

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

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54

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

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sockaddr_in6, PF_INET6,

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

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inet_pton(), connect(),

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61

getnameinfo() */

60

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

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

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63

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

62

64

*/

63

65

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

64

66

strtoimax() */

65

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

67

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

66

72

program_invocation_short_name */

67

73

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

68

74

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

117

123

gnutls_*

118

124

init_gnutls_session(),

119

125

GNUTLS_* */

126

#if GNUTLS_VERSION_NUMBER < 0x030600

120

127

#include <gnutls/openpgp.h>

121

128

/* gnutls_certificate_set_openpgp_key_file(),

122

129

GNUTLS_OPENPGP_FMT_BASE64 */

130

#elif GNUTLS_VERSION_NUMBER >= 0x030606

131

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

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GNUTLS_PKCS_PLAIN,

133

GNUTLS_PKCS_NULL_PASSWORD */

134

#endif

123

135

124

136

/* GPGME */

125

137

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

133

145

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

134

146

#define SECKEY "seckey.txt"

135

147

#define PUBKEY "pubkey.txt"

148

#define TLS_PRIVKEY "tls-privkey.pem"

149

#define TLS_PUBKEY "tls-pubkey.pem"

136

150

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

137

151

138

152

bool debug = false;

234

248

.af = af };

235

249

if(new_server->ip == NULL){

236

250

perror_plus("strdup");

251

free(new_server);

237

252

return false;

238

253

}

239

254

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

240

255

if(ret == -1){

241

256

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);

242

266

return false;

243

267

}

244

268

/* Special case of first server */

256

280

return true;

257

281

}

258

282

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

259

335

/*

260

336

* Initialize GPGME.

261

337

*/

281

357

return false;

282

358

}

283

359

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

284

410

rc = gpgme_data_new_from_fd(&pgp_data, fd);

285

411

if(rc != GPG_ERR_NO_ERROR){

286

412

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

294

420

gpgme_strsource(rc), gpgme_strerror(rc));

295

421

return false;

296

422

}

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

}

297

498

298

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

499

ret = close(fd);

299

500

if(ret == -1){

300

501

perror_plus("close");

301

502

}

340

541

/* Create new GPGME "context" */

341

542

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

342

543

if(rc != GPG_ERR_NO_ERROR){

343

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

344

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

345

gpgme_strerror(rc));

544

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

545

gpgme_strsource(rc), gpgme_strerror(rc));

346

546

return false;

347

547

}

348

548

384

584

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

385

585

rc = gpgme_data_new(&dh_plain);

386

586

if(rc != GPG_ERR_NO_ERROR){

387

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

388

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

587

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

389

588

gpgme_strsource(rc), gpgme_strerror(rc));

390

589

gpgme_data_release(dh_crypto);

391

590

return -1;

404

603

if(result == NULL){

405

604

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

406

605

} else {

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);

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");

411

612

if(result->file_name != NULL){

412

613

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

413

614

}

414

gpgme_recipient_t recipient;

415

recipient = result->recipients;

416

while(recipient != NULL){

615

616

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

617

r = r->next){

417

618

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

418

gpgme_pubkey_algo_name

419

(recipient->pubkey_algo));

420

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

619

gpgme_pubkey_algo_name(r->pubkey_algo));

620

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

421

621

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

422

recipient->status == GPG_ERR_NO_SECKEY

423

? "No" : "Yes");

424

recipient = recipient->next;

622

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

425

623

}

426

624

}

427

625

}

483

681

return plaintext_length;

484

682

}

485

683

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

486

691

__attribute__((warn_unused_result))

487

692

static const char *safer_gnutls_strerror(int value){

488

693

const char *ret = gnutls_strerror(value);

489

if(ret == NULL)

490

ret = "(unknown)";

491

return ret;

694

return safe_string(ret);

492

695

}

493

696

494

697

/* GnuTLS log function callback */

498

701

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

499

702

}

500

703

501

__attribute__((nonnull, warn_unused_result))

704

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

502

705

static int init_gnutls_global(const char *pubkeyfilename,

503

706

const char *seckeyfilename,

707

const char *dhparamsfilename,

504

708

mandos_context *mc){

505

709

int ret;

506

710

508

712

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

509

713

}

510

714

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

518

715

if(debug){

519

716

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

520

717

* - GnuTLS manual

528

725

if(ret != GNUTLS_E_SUCCESS){

529

726

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

530

727

safer_gnutls_strerror(ret));

531

gnutls_global_deinit();

532

728

return -1;

533

729

}

534

730

535

731

if(debug){

536

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

537

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

732

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

733

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

538

734

pubkeyfilename,

539

735

seckeyfilename);

540

736

}

541

737

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

542

751

ret = gnutls_certificate_set_openpgp_key_file

543

752

(mc->cred, pubkeyfilename, seckeyfilename,

544

753

GNUTLS_OPENPGP_FMT_BASE64);

754

#else

755

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

756

#endif

545

757

if(ret != GNUTLS_E_SUCCESS){

546

758

fprintf_plus(stderr,

547

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

759

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

548

760

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

549

761

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

550

762

safer_gnutls_strerror(ret));

559

771

safer_gnutls_strerror(ret));

560

772

goto globalfail;

561

773

}

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);

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

}

570

956

571

957

return 0;

572

958

573

959

globalfail:

574

960

575

961

gnutls_certificate_free_credentials(mc->cred);

576

gnutls_global_deinit();

577

962

gnutls_dh_params_deinit(mc->dh_params);

578

963

return -1;

579

964

}

584

969

int ret;

585

970

/* GnuTLS session creation */

586

971

do {

587

ret = gnutls_init(session, GNUTLS_SERVER);

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

));

588

980

if(quit_now){

589

981

return -1;

590

982

}

631

1023

/* ignore client certificate if any. */

632

1024

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

633

1025

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

635

636

1026

return 0;

637

1027

}

638

1028

640

1030

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

641

1031

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

642

1032

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

643

1199

/* Called when a Mandos server is found */

644

1200

__attribute__((nonnull, warn_unused_result))

645

1201

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

656

1212

int retval = -1;

657

1213

gnutls_session_t session;

658

1214

int pf; /* Protocol family */

1215

bool route_added = false;

659

1216

660

1217

errno = 0;

661

1218

683

1240

bool match = false;

684

1241

{

685

1242

char *interface = NULL;

686

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

687

interface))){

1243

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

1244

mc->interfaces_size,

1245

interface))){

688

1246

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

689

1247

match = true;

690

1248

break;

719

1277

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

720

1278

}

721

1279

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

1280

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

723

1281

if(tcp_sd < 0){

724

1282

int e = errno;

725

1283

perror_plus("socket");

732

1290

goto mandos_end;

733

1291

}

734

1292

735

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

736

1293

if(af == AF_INET6){

737

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

738

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

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);

739

1297

} else { /* IPv4 */

740

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

741

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

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);

742

1301

}

743

1302

if(ret < 0 ){

744

1303

int e = errno;

814

1373

goto mandos_end;

815

1374

}

816

1375

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;

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;

836

1431

}

837

1432

838

1433

const char *out = mandos_protocol_version;

992

1587

&decrypted_buffer, mc);

993

1588

if(decrypted_buffer_size >= 0){

994

1589

1590

clearerr(stdout);

995

1591

written = 0;

996

1592

while(written < (size_t) decrypted_buffer_size){

997

1593

if(quit_now){

1013

1609

}

1014

1610

written += (size_t)ret;

1015

1611

}

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

}

1016

1622

retval = 0;

1017

1623

}

1018

1624

}

1021

1627

1022

1628

mandos_end:

1023

1629

{

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

}

1024

1636

int e = errno;

1025

1637

free(decrypted_buffer);

1026

1638

free(buffer);

1027

1639

if(tcp_sd >= 0){

1028

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

1640

ret = close(tcp_sd);

1029

1641

}

1030

1642

if(ret == -1){

1031

1643

if(e == 0){

1043

1655

return retval;

1044

1656

}

1045

1657

1046

__attribute__((nonnull))

1047

1658

static void resolve_callback(AvahiSServiceResolver *r,

1048

1659

AvahiIfIndex interface,

1049

1660

AvahiProtocol proto,

1066

1677

timed out */

1067

1678

1068

1679

if(quit_now){

1680

avahi_s_service_resolver_free(r);

1069

1681

return;

1070

1682

}

1071

1683

1185

1797

__attribute__((nonnull, warn_unused_result))

1186

1798

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

1187

1799

int ret;

1188

error_t ret_errno;

1800

int old_errno;

1189

1801

1190

1802

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

1191

1803

if(s < 0){

1192

ret_errno = errno;

1804

old_errno = errno;

1193

1805

perror_plus("socket");

1194

errno = ret_errno;

1806

errno = old_errno;

1195

1807

return false;

1196

1808

}

1197

strcpy(ifr->ifr_name, ifname);

1809

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

1810

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

1198

1811

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1199

1812

if(ret == -1){

1200

1813

if(debug){

1201

ret_errno = errno;

1814

old_errno = errno;

1202

1815

perror_plus("ioctl SIOCGIFFLAGS");

1203

errno = ret_errno;

1816

errno = old_errno;

1817

}

1818

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

1819

old_errno = errno;

1820

perror_plus("close");

1821

errno = old_errno;

1204

1822

}

1205

1823

return false;

1206

1824

}

1825

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

1826

old_errno = errno;

1827

perror_plus("close");

1828

errno = old_errno;

1829

}

1207

1830

return true;

1208

1831

}

1209

1832

1451

2074

}

1452

2075

}

1453

2076

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

2077

__attribute__((nonnull))

1511

2078

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

1512

2079

const float delay){

1513

struct dirent **direntries;

2080

struct dirent **direntries = NULL;

1514

2081

if(hookdir_fd == -1){

1515

hookdir_fd = open(hookdir, O_RDONLY);

2082

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2083

| O_CLOEXEC);

1516

2084

if(hookdir_fd == -1){

1517

2085

if(errno == ENOENT){

1518

2086

if(debug){

1525

2093

return;

1526

2094

}

1527

2095

}

1528

#ifdef __GLIBC__

1529

#if __GLIBC_PREREQ(2, 15)

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

}

1530

2101

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

1531

2102

runnable_hook, alphasort);

1532

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

1533

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

1534

alphasort);

1535

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

1536

#else /* not __GLIBC__ */

1537

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

1538

alphasort);

1539

#endif /* not __GLIBC__ */

1540

2103

if(numhooks == -1){

1541

2104

perror_plus("scandir");

2105

close(devnull);

1542

2106

return;

1543

2107

}

1544

2108

struct dirent *direntry;

1545

2109

int ret;

1546

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

1547

2110

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

1548

2111

direntry = direntries[i];

1549

2112

if(debug){

1554

2117

if(hook_pid == 0){

1555

2118

/* Child */

1556

2119

/* Raise privileges */

1557

if(raise_privileges_permanently() != 0){

2120

errno = raise_privileges_permanently();

2121

if(errno != 0){

1558

2122

perror_plus("Failed to raise privileges");

1559

2123

_exit(EX_NOPERM);

1560

2124

}

1572

2136

perror_plus("setgroups");

1573

2137

_exit(EX_NOPERM);

1574

2138

}

1575

ret = dup2(devnull, STDIN_FILENO);

1576

if(ret == -1){

1577

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

1578

_exit(EX_OSERR);

1579

}

1580

ret = close(devnull);

1581

if(ret == -1){

1582

perror_plus("close");

1583

_exit(EX_OSERR);

1584

}

1585

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1586

if(ret == -1){

1587

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

1588

_exit(EX_OSERR);

1589

}

1590

2139

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

1591

2140

if(ret == -1){

1592

2141

perror_plus("setenv");

1627

2176

_exit(EX_OSERR);

1628

2177

}

1629

2178

}

1630

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

2179

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

2180

direntry->d_name,

2181

O_RDONLY));

1631

2182

if(hook_fd == -1){

1632

2183

perror_plus("openat");

1633

2184

_exit(EXIT_FAILURE);

1634

2185

}

1635

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

2186

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

1636

2187

perror_plus("close");

1637

2188

_exit(EXIT_FAILURE);

1638

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

}

1639

2205

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

1640

2206

environ) == -1){

1641

2207

perror_plus("fexecve");

1642

2208

_exit(EXIT_FAILURE);

1643

2209

}

1644

2210

} else {

2211

if(hook_pid == -1){

2212

perror_plus("fork");

2213

free(direntry);

2214

continue;

2215

}

1645

2216

int status;

1646

2217

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

1647

2218

perror_plus("waitpid");

2219

free(direntry);

1648

2220

continue;

1649

2221

}

1650

2222

if(WIFEXITED(status)){

1652

2224

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

1653

2225

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

1654

2226

WEXITSTATUS(status));

2227

free(direntry);

1655

2228

continue;

1656

2229

}

1657

2230

} else if(WIFSIGNALED(status)){

1658

2231

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

1659

2232

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

1660

2233

WTERMSIG(status));

2234

free(direntry);

1661

2235

continue;

1662

2236

} else {

1663

2237

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

1664

2238

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

2239

free(direntry);

1665

2240

continue;

1666

2241

}

1667

2242

}

1669

2244

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

1670

2245

direntry->d_name);

1671

2246

}

2247

free(direntry);

1672

2248

}

1673

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

2249

free(direntries);

2250

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

1674

2251

perror_plus("close");

1675

2252

} else {

1676

2253

hookdir_fd = -1;

1679

2256

}

1680

2257

1681

2258

__attribute__((nonnull, warn_unused_result))

1682

error_t bring_up_interface(const char *const interface,

1683

const float delay){

1684

error_t old_errno = errno;

2259

int bring_up_interface(const char *const interface,

2260

const float delay){

2261

int old_errno = errno;

1685

2262

int ret;

1686

2263

struct ifreq network;

1687

2264

unsigned int if_index = if_nametoindex(interface);

1697

2274

}

1698

2275

1699

2276

if(not interface_is_up(interface)){

1700

error_t ret_errno = 0, ioctl_errno = 0;

2277

int ret_errno = 0;

2278

int ioctl_errno = 0;

1701

2279

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

1702

2280

ret_errno = errno;

1703

2281

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

1716

2294

}

1717

2295

1718

2296

if(quit_now){

1719

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

2297

ret = close(sd);

1720

2298

if(ret == -1){

1721

2299

perror_plus("close");

1722

2300

}

1732

2310

/* Raise privileges */

1733

2311

ret_errno = raise_privileges();

1734

2312

if(ret_errno != 0){

2313

errno = ret_errno;

1735

2314

perror_plus("Failed to raise privileges");

1736

2315

}

1737

2316

1771

2350

}

1772

2351

1773

2352

/* Close the socket */

1774

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

2353

ret = close(sd);

1775

2354

if(ret == -1){

1776

2355

perror_plus("close");

1777

2356

}

1789

2368

1790

2369

/* Sleep checking until interface is running.

1791

2370

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

1792

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

2371

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

1793

2372

if(interface_is_running(interface)){

1794

2373

break;

1795

2374

}

1805

2384

}

1806

2385

1807

2386

__attribute__((nonnull, warn_unused_result))

1808

error_t take_down_interface(const char *const interface){

1809

error_t old_errno = errno;

2387

int take_down_interface(const char *const interface){

2388

int old_errno = errno;

1810

2389

struct ifreq network;

1811

2390

unsigned int if_index = if_nametoindex(interface);

1812

2391

if(if_index == 0){

1815

2394

return ENXIO;

1816

2395

}

1817

2396

if(interface_is_up(interface)){

1818

error_t ret_errno = 0, ioctl_errno = 0;

2397

int ret_errno = 0;

2398

int ioctl_errno = 0;

1819

2399

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

1820

2400

ret_errno = errno;

1821

2401

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

1841

2421

/* Raise privileges */

1842

2422

ret_errno = raise_privileges();

1843

2423

if(ret_errno != 0){

2424

errno = ret_errno;

1844

2425

perror_plus("Failed to raise privileges");

1845

2426

}

1846

2427

1858

2439

}

1859

2440

1860

2441

/* Close the socket */

1861

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

2442

int ret = close(sd);

1862

2443

if(ret == -1){

1863

2444

perror_plus("close");

1864

2445

}

1879

2460

}

1880

2461

1881

2462

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

1882

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

1883

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

1884

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

1885

.interfaces = NULL, .interfaces_size = 0 };

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 };

1886

2476

AvahiSServiceBrowser *sb = NULL;

1887

2477

error_t ret_errno;

1888

2478

int ret;

1897

2487

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1898

2488

const char *seckey = PATHDIR "/" SECKEY;

1899

2489

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;

1900

2495

char *interfaces_hooks = NULL;

1901

2496

1902

2497

bool gnutls_initialized = false;

1949

2544

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

1950

2545

.arg = "FILE",

1951

2546

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

1952

.group = 2 },

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 },

1953

2564

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

1954

2565

.arg = "BITS",

1955

2566

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

1956

2567

" Diffie-Hellman key exchange",

1957

2568

.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 },

1958

2574

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

1959

2575

.arg = "STRING",

1960

2576

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

2006

2622

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

2007

2623

pubkey = arg;

2008

2624

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;

2009

2635

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

2010

2636

errno = 0;

2011

2637

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

2015

2641

}

2016

2642

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

2017

2643

break;

2644

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

2645

dh_params_file = arg;

2646

break;

2018

2647

case 130: /* --priority */

2019

2648

mc.priority = arg;

2020

2649

break;

2043

2672

argp_state_help(state, state->out_stream,

2044

2673

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

2045

2674

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2675

__builtin_unreachable();

2046

2676

case -3: /* --usage */

2047

2677

argp_state_help(state, state->out_stream,

2048

2678

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2679

__builtin_unreachable();

2049

2680

case 'V': /* --version */

2050

2681

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

2051

2682

exit(argp_err_exit_status);

2060

2691

.args_doc = "",

2061

2692

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

2062

2693

" passwords from a Mandos server" };

2063

ret = argp_parse(&argp, argc, argv,

2064

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2065

switch(ret){

2694

ret_errno = argp_parse(&argp, argc, argv,

2695

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2696

switch(ret_errno){

2066

2697

case 0:

2067

2698

break;

2068

2699

case ENOMEM:

2069

2700

default:

2070

errno = ret;

2701

errno = ret_errno;

2071

2702

perror_plus("argp_parse");

2072

2703

exitcode = EX_OSERR;

2073

2704

goto end;

2076

2707

goto end;

2077

2708

}

2078

2709

}

2079

2710

2080

2711

{

2081

2712

/* Work around Debian bug #633582:

2082

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

2713

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

2083

2714

2084

2715

/* Re-raise privileges */

2085

ret_errno = raise_privileges();

2086

if(ret_errno != 0){

2087

errno = ret_errno;

2716

ret = raise_privileges();

2717

if(ret != 0){

2718

errno = ret;

2088

2719

perror_plus("Failed to raise privileges");

2089

2720

} else {

2090

2721

struct stat st;

2106

2737

}

2107

2738

}

2108

2739

}

2109

TEMP_FAILURE_RETRY(close(seckey_fd));

2740

close(seckey_fd);

2110

2741

}

2111

2742

}

2112

2743

2113

2744

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

2114

2745

int pubkey_fd = open(pubkey, O_RDONLY);

2115

2746

if(pubkey_fd == -1){

2127

2758

}

2128

2759

}

2129

2760

}

2130

TEMP_FAILURE_RETRY(close(pubkey_fd));

2131

}

2132

}

2133

2761

close(pubkey_fd);

2762

}

2763

}

2764

2765

if(dh_params_file != NULL

2766

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

2767

int dhparams_fd = open(dh_params_file, O_RDONLY);

2768

if(dhparams_fd == -1){

2769

perror_plus("open");

2770

} else {

2771

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

2772

if(ret == -1){

2773

perror_plus("fstat");

2774

} else {

2775

if(S_ISREG(st.st_mode)

2776

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

2777

ret = fchown(dhparams_fd, uid, gid);

2778

if(ret == -1){

2779

perror_plus("fchown");

2780

}

2781

}

2782

}

2783

close(dhparams_fd);

2784

}

2785

}

2786

2134

2787

/* Lower privileges */

2135

ret_errno = lower_privileges();

2136

if(ret_errno != 0){

2137

errno = ret_errno;

2788

ret = lower_privileges();

2789

if(ret != 0){

2790

errno = ret;

2138

2791

perror_plus("Failed to lower privileges");

2139

2792

}

2140

2793

}

2265

2918

if(ret_errno != 0){

2266

2919

errno = ret_errno;

2267

2920

perror_plus("argz_add");

2921

free(direntries[i]);

2268

2922

continue;

2269

2923

}

2270

2924

if(debug){

2271

2925

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

2272

2926

direntries[i]->d_name);

2273

2927

}

2928

free(direntries[i]);

2274

2929

}

2275

2930

free(direntries);

2276

2931

} else {

2277

free(direntries);

2932

if(ret == 0){

2933

free(direntries);

2934

}

2278

2935

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

2279

2936

exitcode = EXIT_FAILURE;

2280

2937

goto end;

2306

2963

errno = bring_up_interface(interface, delay);

2307

2964

if(not interface_was_up){

2308

2965

if(errno != 0){

2309

perror_plus("Failed to bring up interface");

2966

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

2967

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

2310

2968

} else {

2311

2969

errno = argz_add(&interfaces_to_take_down,

2312

2970

&interfaces_to_take_down_size,

2335

2993

goto end;

2336

2994

}

2337

2995

2338

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

2996

#if GNUTLS_VERSION_NUMBER >= 0x030606

2997

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

2998

#elif GNUTLS_VERSION_NUMBER < 0x030600

2999

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

3000

#else

3001

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

3002

#endif

2339

3003

if(ret == -1){

2340

3004

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

2341

3005

exitcode = EX_UNAVAILABLE;

2463

3127

2464

3128

/* Allocate a new server */

2465

3129

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2466

&config, NULL, NULL, &ret_errno);

3130

&config, NULL, NULL, &ret);

2467

3131

2468

3132

/* Free the Avahi configuration data */

2469

3133

avahi_server_config_free(&config);

2472

3136

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

2473

3137

if(mc.server == NULL){

2474

3138

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

2475

avahi_strerror(ret_errno));

3139

avahi_strerror(ret));

2476

3140

exitcode = EX_UNAVAILABLE;

2477

3141

goto end;

2478

3142

}

2513

3177

end:

2514

3178

2515

3179

if(debug){

2516

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

3180

if(signal_received){

3181

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

3182

argv[0], signal_received,

3183

strsignal(signal_received));

3184

} else {

3185

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

3186

}

2517

3187

}

2518

3188

2519

3189

/* Cleanup things */

2530

3200

2531

3201

if(gnutls_initialized){

2532

3202

gnutls_certificate_free_credentials(mc.cred);

2533

gnutls_global_deinit();

2534

3203

gnutls_dh_params_deinit(mc.dh_params);

2535

3204

}

2536

3205

2544

3213

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

2545

3214

while(mc.current_server != NULL){

2546

3215

server *next = mc.current_server->next;

3216

#ifdef __GNUC__

3217

#pragma GCC diagnostic push

3218

#pragma GCC diagnostic ignored "-Wcast-qual"

3219

#endif

3220

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

3221

#ifdef __GNUC__

3222

#pragma GCC diagnostic pop

3223

#endif

2547

3224

free(mc.current_server);

2548

3225

mc.current_server = next;

2549

3226

}

2551

3228

2552

3229

/* Re-raise privileges */

2553

3230

{

2554

ret_errno = raise_privileges();

2555

if(ret_errno != 0){

3231

ret = raise_privileges();

3232

if(ret != 0){

3233

errno = ret;

2556

3234

perror_plus("Failed to raise privileges");

2557

3235

} else {

2558

3236

2563

3241

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

2564

3242

{

2565

3243

char *interface = NULL;

2566

while((interface=argz_next(interfaces_to_take_down,

2567

interfaces_to_take_down_size,

2568

interface))){

2569

ret_errno = take_down_interface(interface);

2570

if(ret_errno != 0){

2571

errno = ret_errno;

3244

while((interface = argz_next(interfaces_to_take_down,

3245

interfaces_to_take_down_size,

3246

interface))){

3247

ret = take_down_interface(interface);

3248

if(ret != 0){

3249

errno = ret;

2572

3250

perror_plus("Failed to take down interface");

2573

3251

}

2574

3252

}

2579

3257

}

2580

3258

}

2581

3259

2582

ret_errno = lower_privileges_permanently();

2583

if(ret_errno != 0){

3260

ret = lower_privileges_permanently();

3261

if(ret != 0){

3262

errno = ret;

2584

3263

perror_plus("Failed to lower privileges permanently");

2585

3264

}

2586

3265

}

2588

3267

free(interfaces_to_take_down);

2589

3268

free(interfaces_hooks);

2590

3269

3270

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

3271

uintmax_t level){

3272

struct dirent **direntries = NULL;

3273

int dret;

3274

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

3275

O_RDONLY

3276

| O_NOFOLLOW

3277

| O_DIRECTORY

3278

| O_PATH));

3279

if(dir_fd == -1){

3280

perror_plus("open");

3281

return;

3282

}

3283

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

3284

notdotentries, alphasort);

3285

if(numentries >= 0){

3286

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

3287

if(debug){

3288

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

3289

dirname, direntries[i]->d_name);

3290

}

3291

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

3292

if(dret == -1){

3293

if(errno == EISDIR){

3294

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

3295

AT_REMOVEDIR);

3296

}

3297

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

3298

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

3299

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

3300

/* Recurse only in this special case */

3301

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

3302

dret = 0;

3303

}

3304

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

3305

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

3306

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

3307

}

3308

}

3309

free(direntries[i]);

3310

}

3311

3312

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

3313

free(direntries);

3314

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3315

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

3316

perror_plus("rmdir");

3317

}

3318

} else {

3319

perror_plus("scandirat");

3320

}

3321

close(dir_fd);

3322

}

3323

2591

3324

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

2592

3325

if(tempdir != NULL){

2593

struct dirent **direntries = NULL;

2594

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

2595

O_NOFOLLOW));

2596

if(tempdir_fd == -1){

2597

perror_plus("open");

2598

} else {

2599

#ifdef __GLIBC__

2600

#if __GLIBC_PREREQ(2, 15)

2601

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

2602

notdotentries, alphasort);

2603

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

2604

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

2605

alphasort);

2606

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

2607

#else /* not __GLIBC__ */

2608

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

2609

alphasort);

2610

#endif /* not __GLIBC__ */

2611

if(numentries > 0){

2612

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

2613

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

2614

if(ret == -1){

2615

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

2616

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

2617

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

2618

}

2619

}

2620

2621

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

2622

free(direntries);

2623

if(numentries == -1){

2624

perror_plus("scandir");

2625

}

2626

ret = rmdir(tempdir);

2627

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

2628

perror_plus("rmdir");

2629

}

2630

}

2631

TEMP_FAILURE_RETRY(close(tempdir_fd));

2632

}

3326

clean_dir_at(-1, tempdir, 0);

2633

3327

}

2634

3328

2635

3329

if(quit_now){