/mandos/trunk : revision 1221

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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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*

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* This file is part of Mandos.

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*

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

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

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

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* (at your option) any later version.

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*

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

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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

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* General Public License for more details.

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*

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

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* along with this program. If not, see

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

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

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29

*

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

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31

*/

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47

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

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

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#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() */

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

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

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

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64

*/

63

65

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

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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,

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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

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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

if(clock_settime(CLOCK_REALTIME, &keystat.st_mtim) != 0){

400

perror_plus("clock_settime");

401

}

402

ret = lower_privileges();

403

if(ret != 0){

404

errno = ret;

405

perror_plus("Failed to lower privileges");

406

}

407

} while(false);

408

284

409

rc = gpgme_data_new_from_fd(&pgp_data, fd);

285

410

if(rc != GPG_ERR_NO_ERROR){

286

411

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

294

419

gpgme_strsource(rc), gpgme_strerror(rc));

295

420

return false;

296

421

}

422

{

423

gpgme_import_result_t import_result

424

= gpgme_op_import_result(mc->ctx);

425

if((import_result->imported < 1

426

or import_result->not_imported > 0)

427

and import_result->unchanged == 0){

428

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

429

fprintf_plus(stderr,

430

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

431

import_result->considered);

432

fprintf_plus(stderr,

433

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

434

import_result->no_user_id);

435

fprintf_plus(stderr,

436

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

437

import_result->imported);

438

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

439

import_result->imported_rsa);

440

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

441

import_result->unchanged);

442

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

443

import_result->new_user_ids);

444

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

445

import_result->new_sub_keys);

446

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

447

import_result->new_signatures);

448

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

449

import_result->new_revocations);

450

fprintf_plus(stderr,

451

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

452

import_result->secret_read);

453

fprintf_plus(stderr,

454

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

455

import_result->secret_imported);

456

fprintf_plus(stderr,

457

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

458

import_result->secret_unchanged);

459

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

460

import_result->not_imported);

461

for(gpgme_import_status_t import_status

462

= import_result->imports;

463

import_status != NULL;

464

import_status = import_status->next){

465

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

466

import_status->fpr);

467

if(import_status->result != GPG_ERR_NO_ERROR){

468

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

469

gpgme_strsource(import_status->result),

470

gpgme_strerror(import_status->result));

471

}

472

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

473

fprintf_plus(stderr,

474

import_status->status & GPGME_IMPORT_NEW

475

? "The key was new.\n"

476

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

477

fprintf_plus(stderr,

478

import_status->status & GPGME_IMPORT_UID

479

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

480

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

481

fprintf_plus(stderr,

482

import_status->status & GPGME_IMPORT_SIG

483

? "The key contained new signatures.\n"

484

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

485

fprintf_plus(stderr,

486

import_status->status & GPGME_IMPORT_SUBKEY

487

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

488

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

489

fprintf_plus(stderr,

490

import_status->status & GPGME_IMPORT_SECRET

491

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

492

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

493

}

494

return false;

495

}

496

}

297

497

298

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

498

ret = close(fd);

299

499

if(ret == -1){

300

500

perror_plus("close");

301

501

}

340

540

/* Create new GPGME "context" */

341

541

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

342

542

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));

543

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

544

gpgme_strsource(rc), gpgme_strerror(rc));

346

545

return false;

347

546

}

348

547

384

583

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

385

584

rc = gpgme_data_new(&dh_plain);

386

585

if(rc != GPG_ERR_NO_ERROR){

387

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

388

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

586

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

389

587

gpgme_strsource(rc), gpgme_strerror(rc));

390

588

gpgme_data_release(dh_crypto);

391

589

return -1;

404

602

if(result == NULL){

405

603

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

406

604

} 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);

605

if(result->unsupported_algorithm != NULL) {

606

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

607

result->unsupported_algorithm);

608

}

609

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

610

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

411

611

if(result->file_name != NULL){

412

612

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

413

613

}

414

gpgme_recipient_t recipient;

415

recipient = result->recipients;

416

while(recipient != NULL){

614

615

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

616

r = r->next){

417

617

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);

618

gpgme_pubkey_algo_name(r->pubkey_algo));

619

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

421

620

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

422

recipient->status == GPG_ERR_NO_SECKEY

423

? "No" : "Yes");

424

recipient = recipient->next;

621

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

425

622

}

426

623

}

427

624

}

483

680

return plaintext_length;

484

681

}

485

682

683

__attribute__((warn_unused_result, const))

684

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

685

if(str == NULL)

686

return "(unknown)";

687

return str;

688

}

689

486

690

__attribute__((warn_unused_result))

487

691

static const char *safer_gnutls_strerror(int value){

488

692

const char *ret = gnutls_strerror(value);

489

if(ret == NULL)

490

ret = "(unknown)";

491

return ret;

693

return safe_string(ret);

492

694

}

493

695

494

696

/* GnuTLS log function callback */

498

700

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

499

701

}

500

702

501

__attribute__((nonnull, warn_unused_result))

703

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

502

704

static int init_gnutls_global(const char *pubkeyfilename,

503

705

const char *seckeyfilename,

706

const char *dhparamsfilename,

504

707

mandos_context *mc){

505

708

int ret;

506

709

508

711

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

509

712

}

510

713

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

714

if(debug){

519

715

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

520

716

* - GnuTLS manual

528

724

if(ret != GNUTLS_E_SUCCESS){

529

725

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

530

726

safer_gnutls_strerror(ret));

531

gnutls_global_deinit();

532

727

return -1;

533

728

}

534

729

535

730

if(debug){

536

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

537

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

731

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

732

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

538

733

pubkeyfilename,

539

734

seckeyfilename);

540

735

}

541

736

737

#if GNUTLS_VERSION_NUMBER >= 0x030606

738

ret = gnutls_certificate_set_rawpk_key_file

739

(mc->cred, pubkeyfilename, seckeyfilename,

740

GNUTLS_X509_FMT_PEM, /* format */

741

NULL, /* pass */

742

/* key_usage */

743

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

744

NULL, /* names */

745

0, /* names_length */

746

/* privkey_flags */

747

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

748

0); /* pkcs11_flags */

749

#elif GNUTLS_VERSION_NUMBER < 0x030600

542

750

ret = gnutls_certificate_set_openpgp_key_file

543

751

(mc->cred, pubkeyfilename, seckeyfilename,

544

752

GNUTLS_OPENPGP_FMT_BASE64);

753

#else

754

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

755

#endif

545

756

if(ret != GNUTLS_E_SUCCESS){

546

757

fprintf_plus(stderr,

547

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

758

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

548

759

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

549

760

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

550

761

safer_gnutls_strerror(ret));

559

770

safer_gnutls_strerror(ret));

560

771

goto globalfail;

561

772

}

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);

773

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

774

if(dhparamsfilename != NULL){

775

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

776

do {

777

int dhpfile = open(dhparamsfilename, O_RDONLY);

778

if(dhpfile == -1){

779

perror_plus("open");

780

dhparamsfilename = NULL;

781

break;

782

}

783

size_t params_capacity = 0;

784

while(true){

785

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

786

(size_t)params.size,

787

(size_t)params_capacity);

788

if(params_capacity == 0){

789

perror_plus("incbuffer");

790

free(params.data);

791

params.data = NULL;

792

dhparamsfilename = NULL;

793

break;

794

}

795

ssize_t bytes_read = read(dhpfile,

796

params.data + params.size,

797

BUFFER_SIZE);

798

/* EOF */

799

if(bytes_read == 0){

800

break;

801

}

802

/* check bytes_read for failure */

803

if(bytes_read < 0){

804

perror_plus("read");

805

free(params.data);

806

params.data = NULL;

807

dhparamsfilename = NULL;

808

break;

809

}

810

params.size += (unsigned int)bytes_read;

811

}

812

ret = close(dhpfile);

813

if(ret == -1){

814

perror_plus("close");

815

}

816

if(params.data == NULL){

817

dhparamsfilename = NULL;

818

}

819

if(dhparamsfilename == NULL){

820

break;

821

}

822

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

823

GNUTLS_X509_FMT_PEM);

824

if(ret != GNUTLS_E_SUCCESS){

825

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

826

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

827

safer_gnutls_strerror(ret));

828

dhparamsfilename = NULL;

829

}

830

free(params.data);

831

} while(false);

832

}

833

if(dhparamsfilename == NULL){

834

if(mc->dh_bits == 0){

835

#if GNUTLS_VERSION_NUMBER < 0x030600

836

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

837

/* Try to read the private key file */

838

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

839

do {

840

int secfile = open(seckeyfilename, O_RDONLY);

841

if(secfile == -1){

842

perror_plus("open");

843

break;

844

}

845

size_t buffer_capacity = 0;

846

while(true){

847

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

848

(size_t)buffer.size,

849

(size_t)buffer_capacity);

850

if(buffer_capacity == 0){

851

perror_plus("incbuffer");

852

free(buffer.data);

853

buffer.data = NULL;

854

break;

855

}

856

ssize_t bytes_read = read(secfile,

857

buffer.data + buffer.size,

858

BUFFER_SIZE);

859

/* EOF */

860

if(bytes_read == 0){

861

break;

862

}

863

/* check bytes_read for failure */

864

if(bytes_read < 0){

865

perror_plus("read");

866

free(buffer.data);

867

buffer.data = NULL;

868

break;

869

}

870

buffer.size += (unsigned int)bytes_read;

871

}

872

close(secfile);

873

} while(false);

874

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

875

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

876

if(buffer.data != NULL){

877

{

878

gnutls_openpgp_privkey_t privkey = NULL;

879

ret = gnutls_openpgp_privkey_init(&privkey);

880

if(ret != GNUTLS_E_SUCCESS){

881

fprintf_plus(stderr, "Error initializing OpenPGP key"

882

" structure: %s",

883

safer_gnutls_strerror(ret));

884

free(buffer.data);

885

buffer.data = NULL;

886

} else {

887

ret = gnutls_openpgp_privkey_import

888

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

889

if(ret != GNUTLS_E_SUCCESS){

890

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

891

safer_gnutls_strerror(ret));

892

privkey = NULL;

893

}

894

free(buffer.data);

895

buffer.data = NULL;

896

if(privkey != NULL){

897

/* Use private key to suggest an appropriate

898

sec_param */

899

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

900

gnutls_openpgp_privkey_deinit(privkey);

901

if(debug){

902

fprintf_plus(stderr, "This OpenPGP key implies using"

903

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

904

safe_string(gnutls_sec_param_get_name

905

(sec_param)));

906

}

907

}

908

}

909

}

910

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

911

/* Err on the side of caution */

912

sec_param = GNUTLS_SEC_PARAM_ULTRA;

913

if(debug){

914

fprintf_plus(stderr, "Falling back to security parameter"

915

" \"%s\"\n",

916

safe_string(gnutls_sec_param_get_name

917

(sec_param)));

918

}

919

}

920

}

921

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

922

if(uret != 0){

923

mc->dh_bits = uret;

924

if(debug){

925

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

926

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

927

safe_string(gnutls_sec_param_get_name

928

(sec_param)),

929

mc->dh_bits);

930

}

931

} else {

932

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

933

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

934

safe_string(gnutls_sec_param_get_name

935

(sec_param)),

936

safer_gnutls_strerror(ret));

937

goto globalfail;

938

}

939

#endif

940

} else { /* dh_bits != 0 */

941

if(debug){

942

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

943

mc->dh_bits);

944

}

945

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

946

if(ret != GNUTLS_E_SUCCESS){

947

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

948

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

949

safer_gnutls_strerror(ret));

950

goto globalfail;

951

}

952

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

953

}

954

}

570

955

571

956

return 0;

572

957

573

958

globalfail:

574

959

575

960

gnutls_certificate_free_credentials(mc->cred);

576

gnutls_global_deinit();

577

961

gnutls_dh_params_deinit(mc->dh_params);

578

962

return -1;

579

963

}

584

968

int ret;

585

969

/* GnuTLS session creation */

586

970

do {

587

ret = gnutls_init(session, GNUTLS_SERVER);

971

ret = gnutls_init(session, (GNUTLS_SERVER

972

#if GNUTLS_VERSION_NUMBER >= 0x030506

973

| GNUTLS_NO_TICKETS

974

#endif

975

#if GNUTLS_VERSION_NUMBER >= 0x030606

976

| GNUTLS_ENABLE_RAWPK

977

#endif

978

));

588

979

if(quit_now){

589

980

return -1;

590

981

}

631

1022

/* ignore client certificate if any. */

632

1023

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

633

1024

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

635

636

1025

return 0;

637

1026

}

638

1027

640

1029

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

641

1030

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

642

1031

1032

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

1033

__attribute__((nonnull, warn_unused_result))

1034

static bool add_delete_local_route(const bool add,

1035

const char *address,

1036

AvahiIfIndex if_index){

1037

int ret;

1038

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

1039

char add_arg[] = "add";

1040

char delete_arg[] = "delete";

1041

char debug_flag[] = "--debug";

1042

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1043

if(pluginhelperdir == NULL){

1044

if(debug){

1045

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1046

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

1047

}

1048

return false;

1049

}

1050

1051

char interface[IF_NAMESIZE];

1052

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

1053

perror_plus("if_indextoname");

1054

return false;

1055

}

1056

1057

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

1058

if(devnull == -1){

1059

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

1060

return false;

1061

}

1062

pid_t pid = fork();

1063

if(pid == 0){

1064

/* Child */

1065

/* Raise privileges */

1066

errno = raise_privileges_permanently();

1067

if(errno != 0){

1068

perror_plus("Failed to raise privileges");

1069

/* _exit(EX_NOPERM); */

1070

} else {

1071

/* Set group */

1072

errno = 0;

1073

ret = setgid(0);

1074

if(ret == -1){

1075

perror_plus("setgid");

1076

close(devnull);

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

close(devnull);

1085

_exit(EX_NOPERM);

1086

}

1087

}

1088

ret = dup2(devnull, STDIN_FILENO);

1089

if(ret == -1){

1090

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

1091

close(devnull);

1092

_exit(EX_OSERR);

1093

}

1094

ret = close(devnull);

1095

if(ret == -1){

1096

perror_plus("close");

1097

}

1098

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1099

if(ret == -1){

1100

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

1101

_exit(EX_OSERR);

1102

}

1103

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

1104

O_RDONLY

1105

| O_DIRECTORY

1106

| O_PATH

1107

| O_CLOEXEC));

1108

if(helperdir_fd == -1){

1109

perror_plus("open");

1110

_exit(EX_UNAVAILABLE);

1111

}

1112

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

1113

helper, O_RDONLY));

1114

if(helper_fd == -1){

1115

perror_plus("openat");

1116

close(helperdir_fd);

1117

_exit(EX_UNAVAILABLE);

1118

}

1119

close(helperdir_fd);

1120

#ifdef __GNUC__

1121

#pragma GCC diagnostic push

1122

#pragma GCC diagnostic ignored "-Wcast-qual"

1123

#endif

1124

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

1125

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

1126

interface, debug ? debug_flag : NULL, NULL },

1127

environ) == -1){

1128

#ifdef __GNUC__

1129

#pragma GCC diagnostic pop

1130

#endif

1131

perror_plus("fexecve");

1132

_exit(EXIT_FAILURE);

1133

}

1134

}

1135

if(pid == -1){

1136

perror_plus("fork");

1137

close(devnull);

1138

return false;

1139

}

1140

ret = close(devnull);

1141

if(ret == -1){

1142

perror_plus("close");

1143

}

1144

int status;

1145

pid_t pret = -1;

1146

errno = 0;

1147

do {

1148

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

1149

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

1150

int errno_raising = 0;

1151

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

1152

errno_raising = errno;

1153

perror_plus("Failed to raise privileges in order to"

1154

" kill helper program");

1155

}

1156

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

1157

perror_plus("kill");

1158

}

1159

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

1160

perror_plus("Failed to lower privileges after killing"

1161

" helper program");

1162

}

1163

return false;

1164

}

1165

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

1166

if(pret == -1){

1167

perror_plus("waitpid");

1168

return false;

1169

}

1170

if(WIFEXITED(status)){

1171

if(WEXITSTATUS(status) != 0){

1172

fprintf_plus(stderr, "Error: iprouteadddel exited"

1173

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

1174

return false;

1175

}

1176

return true;

1177

}

1178

if(WIFSIGNALED(status)){

1179

fprintf_plus(stderr, "Error: iprouteadddel died by"

1180

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

1181

return false;

1182

}

1183

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

1184

return false;

1185

}

1186

1187

__attribute__((nonnull, warn_unused_result))

1188

static bool add_local_route(const char *address,

1189

AvahiIfIndex if_index){

1190

if(debug){

1191

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

1192

}

1193

return add_delete_local_route(true, address, if_index);

1194

}

1195

1196

__attribute__((nonnull, warn_unused_result))

1197

static bool delete_local_route(const char *address,

1198

AvahiIfIndex if_index){

1199

if(debug){

1200

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

1201

}

1202

return add_delete_local_route(false, address, if_index);

1203

}

1204

643

1205

/* Called when a Mandos server is found */

644

1206

__attribute__((nonnull, warn_unused_result))

645

1207

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

656

1218

int retval = -1;

657

1219

gnutls_session_t session;

658

1220

int pf; /* Protocol family */

1221

bool route_added = false;

659

1222

660

1223

errno = 0;

661

1224

683

1246

bool match = false;

684

1247

{

685

1248

char *interface = NULL;

686

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

687

interface))){

1249

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

1250

mc->interfaces_size,

1251

interface))){

688

1252

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

689

1253

match = true;

690

1254

break;

719

1283

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

720

1284

}

721

1285

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

1286

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

723

1287

if(tcp_sd < 0){

724

1288

int e = errno;

725

1289

perror_plus("socket");

732

1296

goto mandos_end;

733

1297

}

734

1298

735

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

736

1299

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);

1300

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

1301

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

1302

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

739

1303

} 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);

1304

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

1305

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

1306

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

742

1307

}

743

1308

if(ret < 0 ){

744

1309

int e = errno;

814

1379

goto mandos_end;

815

1380

}

816

1381

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;

1382

while(true){

1383

if(af == AF_INET6){

1384

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

1385

sizeof(struct sockaddr_in6));

1386

} else {

1387

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

1388

sizeof(struct sockaddr_in));

1389

}

1390

if(ret < 0){

1391

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

1392

and if_index != AVAHI_IF_UNSPEC

1393

and connect_to == NULL

1394

and not route_added and

1395

((af == AF_INET6 and not

1396

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1397

&to)->sin6_addr)))

1398

or (af == AF_INET and

1399

/* Not a a IPv4LL address */

1400

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

1401

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

1402

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

1403

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

1404

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

1405

connect to a Mandos server announced by Avahi on a server

1406

host with a global address. Work around this by retrying

1407

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

1408

1409

Avahi bug reference:

1410

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

1411

https://bugs.debian.org/587961

1412

*/

1413

if(debug){

1414

fprintf_plus(stderr, "Mandos server unreachable, trying"

1415

" direct route\n");

1416

}

1417

int e = errno;

1418

route_added = add_local_route(ip, if_index);

1419

if(route_added){

1420

continue;

1421

}

1422

errno = e;

1423

}

1424

if(errno != ECONNREFUSED or debug){

1425

int e = errno;

1426

perror_plus("connect");

1427

errno = e;

1428

}

1429

goto mandos_end;

1430

}

1431

1432

if(quit_now){

1433

errno = EINTR;

1434

goto mandos_end;

1435

}

1436

break;

836

1437

}

837

1438

838

1439

const char *out = mandos_protocol_version;

992

1593

&decrypted_buffer, mc);

993

1594

if(decrypted_buffer_size >= 0){

994

1595

1596

clearerr(stdout);

995

1597

written = 0;

996

1598

while(written < (size_t) decrypted_buffer_size){

997

1599

if(quit_now){

1013

1615

}

1014

1616

written += (size_t)ret;

1015

1617

}

1618

ret = fflush(stdout);

1619

if(ret != 0){

1620

int e = errno;

1621

if(debug){

1622

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

1623

strerror(errno));

1624

}

1625

errno = e;

1626

goto mandos_end;

1627

}

1016

1628

retval = 0;

1017

1629

}

1018

1630

}

1021

1633

1022

1634

mandos_end:

1023

1635

{

1636

if(route_added){

1637

if(not delete_local_route(ip, if_index)){

1638

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

1639

" interface %d", ip, if_index);

1640

}

1641

}

1024

1642

int e = errno;

1025

1643

free(decrypted_buffer);

1026

1644

free(buffer);

1027

1645

if(tcp_sd >= 0){

1028

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

1646

ret = close(tcp_sd);

1029

1647

}

1030

1648

if(ret == -1){

1031

1649

if(e == 0){

1043

1661

return retval;

1044

1662

}

1045

1663

1046

__attribute__((nonnull))

1047

1664

static void resolve_callback(AvahiSServiceResolver *r,

1048

1665

AvahiIfIndex interface,

1049

1666

AvahiProtocol proto,

1066

1683

timed out */

1067

1684

1068

1685

if(quit_now){

1686

avahi_s_service_resolver_free(r);

1069

1687

return;

1070

1688

}

1071

1689

1185

1803

__attribute__((nonnull, warn_unused_result))

1186

1804

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

1187

1805

int ret;

1188

error_t ret_errno;

1806

int old_errno;

1189

1807

1190

1808

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

1191

1809

if(s < 0){

1192

ret_errno = errno;

1810

old_errno = errno;

1193

1811

perror_plus("socket");

1194

errno = ret_errno;

1812

errno = old_errno;

1195

1813

return false;

1196

1814

}

1197

strcpy(ifr->ifr_name, ifname);

1815

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

1816

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

1198

1817

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1199

1818

if(ret == -1){

1200

1819

if(debug){

1201

ret_errno = errno;

1820

old_errno = errno;

1202

1821

perror_plus("ioctl SIOCGIFFLAGS");

1203

errno = ret_errno;

1822

errno = old_errno;

1823

}

1824

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

1825

old_errno = errno;

1826

perror_plus("close");

1827

errno = old_errno;

1204

1828

}

1205

1829

return false;

1206

1830

}

1831

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

1832

old_errno = errno;

1833

perror_plus("close");

1834

errno = old_errno;

1835

}

1207

1836

return true;

1208

1837

}

1209

1838

1451

2080

}

1452

2081

}

1453

2082

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

2083

__attribute__((nonnull))

1511

2084

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

1512

2085

const float delay){

1513

struct dirent **direntries;

2086

struct dirent **direntries = NULL;

1514

2087

if(hookdir_fd == -1){

1515

hookdir_fd = open(hookdir, O_RDONLY);

2088

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2089

| O_CLOEXEC);

1516

2090

if(hookdir_fd == -1){

1517

2091

if(errno == ENOENT){

1518

2092

if(debug){

1525

2099

return;

1526

2100

}

1527

2101

}

1528

#ifdef __GLIBC__

1529

#if __GLIBC_PREREQ(2, 15)

2102

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

2103

if(devnull == -1){

2104

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

2105

return;

2106

}

1530

2107

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

1531

2108

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

2109

if(numhooks == -1){

1541

2110

perror_plus("scandir");

2111

close(devnull);

1542

2112

return;

1543

2113

}

1544

2114

struct dirent *direntry;

1545

2115

int ret;

1546

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

1547

2116

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

1548

2117

direntry = direntries[i];

1549

2118

if(debug){

1554

2123

if(hook_pid == 0){

1555

2124

/* Child */

1556

2125

/* Raise privileges */

1557

if(raise_privileges_permanently() != 0){

2126

errno = raise_privileges_permanently();

2127

if(errno != 0){

1558

2128

perror_plus("Failed to raise privileges");

1559

2129

_exit(EX_NOPERM);

1560

2130

}

1572

2142

perror_plus("setgroups");

1573

2143

_exit(EX_NOPERM);

1574

2144

}

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

2145

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

1591

2146

if(ret == -1){

1592

2147

perror_plus("setenv");

1627

2182

_exit(EX_OSERR);

1628

2183

}

1629

2184

}

1630

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

2185

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

2186

direntry->d_name,

2187

O_RDONLY));

1631

2188

if(hook_fd == -1){

1632

2189

perror_plus("openat");

1633

2190

_exit(EXIT_FAILURE);

1634

2191

}

1635

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

2192

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

1636

2193

perror_plus("close");

1637

2194

_exit(EXIT_FAILURE);

1638

2195

}

2196

ret = dup2(devnull, STDIN_FILENO);

2197

if(ret == -1){

2198

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

2199

_exit(EX_OSERR);

2200

}

2201

ret = close(devnull);

2202

if(ret == -1){

2203

perror_plus("close");

2204

_exit(EX_OSERR);

2205

}

2206

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2207

if(ret == -1){

2208

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

2209

_exit(EX_OSERR);

2210

}

1639

2211

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

1640

2212

environ) == -1){

1641

2213

perror_plus("fexecve");

1642

2214

_exit(EXIT_FAILURE);

1643

2215

}

1644

2216

} else {

2217

if(hook_pid == -1){

2218

perror_plus("fork");

2219

free(direntry);

2220

continue;

2221

}

1645

2222

int status;

1646

2223

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

1647

2224

perror_plus("waitpid");

2225

free(direntry);

1648

2226

continue;

1649

2227

}

1650

2228

if(WIFEXITED(status)){

1652

2230

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

1653

2231

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

1654

2232

WEXITSTATUS(status));

2233

free(direntry);

1655

2234

continue;

1656

2235

}

1657

2236

} else if(WIFSIGNALED(status)){

1658

2237

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

1659

2238

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

1660

2239

WTERMSIG(status));

2240

free(direntry);

1661

2241

continue;

1662

2242

} else {

1663

2243

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

1664

2244

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

2245

free(direntry);

1665

2246

continue;

1666

2247

}

1667

2248

}

1669

2250

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

1670

2251

direntry->d_name);

1671

2252

}

2253

free(direntry);

1672

2254

}

1673

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

2255

free(direntries);

2256

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

1674

2257

perror_plus("close");

1675

2258

} else {

1676

2259

hookdir_fd = -1;

1679

2262

}

1680

2263

1681

2264

__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;

2265

int bring_up_interface(const char *const interface,

2266

const float delay){

2267

int old_errno = errno;

1685

2268

int ret;

1686

2269

struct ifreq network;

1687

2270

unsigned int if_index = if_nametoindex(interface);

1697

2280

}

1698

2281

1699

2282

if(not interface_is_up(interface)){

1700

error_t ret_errno = 0, ioctl_errno = 0;

2283

int ret_errno = 0;

2284

int ioctl_errno = 0;

1701

2285

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

1702

2286

ret_errno = errno;

1703

2287

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

1716

2300

}

1717

2301

1718

2302

if(quit_now){

1719

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

2303

ret = close(sd);

1720

2304

if(ret == -1){

1721

2305

perror_plus("close");

1722

2306

}

1732

2316

/* Raise privileges */

1733

2317

ret_errno = raise_privileges();

1734

2318

if(ret_errno != 0){

2319

errno = ret_errno;

1735

2320

perror_plus("Failed to raise privileges");

1736

2321

}

1737

2322

1771

2356

}

1772

2357

1773

2358

/* Close the socket */

1774

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

2359

ret = close(sd);

1775

2360

if(ret == -1){

1776

2361

perror_plus("close");

1777

2362

}

1789

2374

1790

2375

/* Sleep checking until interface is running.

1791

2376

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

1792

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

2377

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

1793

2378

if(interface_is_running(interface)){

1794

2379

break;

1795

2380

}

1805

2390

}

1806

2391

1807

2392

__attribute__((nonnull, warn_unused_result))

1808

error_t take_down_interface(const char *const interface){

1809

error_t old_errno = errno;

2393

int take_down_interface(const char *const interface){

2394

int old_errno = errno;

1810

2395

struct ifreq network;

1811

2396

unsigned int if_index = if_nametoindex(interface);

1812

2397

if(if_index == 0){

1815

2400

return ENXIO;

1816

2401

}

1817

2402

if(interface_is_up(interface)){

1818

error_t ret_errno = 0, ioctl_errno = 0;

2403

int ret_errno = 0;

2404

int ioctl_errno = 0;

1819

2405

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

1820

2406

ret_errno = errno;

1821

2407

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

1841

2427

/* Raise privileges */

1842

2428

ret_errno = raise_privileges();

1843

2429

if(ret_errno != 0){

2430

errno = ret_errno;

1844

2431

perror_plus("Failed to raise privileges");

1845

2432

}

1846

2433

1858

2445

}

1859

2446

1860

2447

/* Close the socket */

1861

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

2448

int ret = close(sd);

1862

2449

if(ret == -1){

1863

2450

perror_plus("close");

1864

2451

}

1879

2466

}

1880

2467

1881

2468

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 };

2469

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

2470

#if GNUTLS_VERSION_NUMBER >= 0x030606

2471

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

2472

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

2473

":%PROFILE_ULTRA",

2474

#elif GNUTLS_VERSION_NUMBER < 0x030600

2475

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

2476

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

2477

#else

2478

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

2479

#endif

2480

.current_server = NULL, .interfaces = NULL,

2481

.interfaces_size = 0 };

1886

2482

AvahiSServiceBrowser *sb = NULL;

1887

2483

error_t ret_errno;

1888

2484

int ret;

1897

2493

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1898

2494

const char *seckey = PATHDIR "/" SECKEY;

1899

2495

const char *pubkey = PATHDIR "/" PUBKEY;

2496

#if GNUTLS_VERSION_NUMBER >= 0x030606

2497

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2498

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2499

#endif

2500

const char *dh_params_file = NULL;

1900

2501

char *interfaces_hooks = NULL;

1901

2502

1902

2503

bool gnutls_initialized = false;

1949

2550

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

1950

2551

.arg = "FILE",

1951

2552

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

1952

.group = 2 },

2553

.group = 1 },

2554

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

2555

.arg = "FILE",

2556

#if GNUTLS_VERSION_NUMBER >= 0x030606

2557

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

2558

#else

2559

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

2560

#endif

2561

.group = 1 },

2562

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

2563

.arg = "FILE",

2564

#if GNUTLS_VERSION_NUMBER >= 0x030606

2565

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

2566

#else

2567

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

2568

#endif

2569

.group = 1 },

1953

2570

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

1954

2571

.arg = "BITS",

1955

2572

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

1956

2573

" Diffie-Hellman key exchange",

1957

2574

.group = 2 },

2575

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

2576

.arg = "FILE",

2577

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

2578

" for the Diffie-Hellman key exchange",

2579

.group = 2 },

1958

2580

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

1959

2581

.arg = "STRING",

1960

2582

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

2006

2628

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

2007

2629

pubkey = arg;

2008

2630

break;

2631

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

2632

#if GNUTLS_VERSION_NUMBER >= 0x030606

2633

tls_privkey = arg;

2634

#endif

2635

break;

2636

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

2637

#if GNUTLS_VERSION_NUMBER >= 0x030606

2638

tls_pubkey = arg;

2639

#endif

2640

break;

2009

2641

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

2010

2642

errno = 0;

2011

2643

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

2015

2647

}

2016

2648

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

2017

2649

break;

2650

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

2651

dh_params_file = arg;

2652

break;

2018

2653

case 130: /* --priority */

2019

2654

mc.priority = arg;

2020

2655

break;

2043

2678

argp_state_help(state, state->out_stream,

2044

2679

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

2045

2680

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2681

__builtin_unreachable();

2046

2682

case -3: /* --usage */

2047

2683

argp_state_help(state, state->out_stream,

2048

2684

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2685

__builtin_unreachable();

2049

2686

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

2050

2687

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

2051

2688

exit(argp_err_exit_status);

2060

2697

.args_doc = "",

2061

2698

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

2062

2699

" passwords from a Mandos server" };

2063

ret = argp_parse(&argp, argc, argv,

2064

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2065

switch(ret){

2700

ret_errno = argp_parse(&argp, argc, argv,

2701

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2702

switch(ret_errno){

2066

2703

case 0:

2067

2704

break;

2068

2705

case ENOMEM:

2069

2706

default:

2070

errno = ret;

2707

errno = ret_errno;

2071

2708

perror_plus("argp_parse");

2072

2709

exitcode = EX_OSERR;

2073

2710

goto end;

2076

2713

goto end;

2077

2714

}

2078

2715

}

2079

2716

2080

2717

{

2081

2718

/* Work around Debian bug #633582:

2082

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

2719

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

2083

2720

2084

2721

/* Re-raise privileges */

2085

ret_errno = raise_privileges();

2086

if(ret_errno != 0){

2087

errno = ret_errno;

2722

ret = raise_privileges();

2723

if(ret != 0){

2724

errno = ret;

2088

2725

perror_plus("Failed to raise privileges");

2089

2726

} else {

2090

2727

struct stat st;

2106

2743

}

2107

2744

}

2108

2745

}

2109

TEMP_FAILURE_RETRY(close(seckey_fd));

2746

close(seckey_fd);

2110

2747

}

2111

2748

}

2112

2749

2113

2750

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

2114

2751

int pubkey_fd = open(pubkey, O_RDONLY);

2115

2752

if(pubkey_fd == -1){

2127

2764

}

2128

2765

}

2129

2766

}

2130

TEMP_FAILURE_RETRY(close(pubkey_fd));

2131

}

2132

}

2133

2767

close(pubkey_fd);

2768

}

2769

}

2770

2771

if(dh_params_file != NULL

2772

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

2773

int dhparams_fd = open(dh_params_file, O_RDONLY);

2774

if(dhparams_fd == -1){

2775

perror_plus("open");

2776

} else {

2777

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

2778

if(ret == -1){

2779

perror_plus("fstat");

2780

} else {

2781

if(S_ISREG(st.st_mode)

2782

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

2783

ret = fchown(dhparams_fd, uid, gid);

2784

if(ret == -1){

2785

perror_plus("fchown");

2786

}

2787

}

2788

}

2789

close(dhparams_fd);

2790

}

2791

}

2792

2134

2793

/* Lower privileges */

2135

ret_errno = lower_privileges();

2136

if(ret_errno != 0){

2137

errno = ret_errno;

2794

ret = lower_privileges();

2795

if(ret != 0){

2796

errno = ret;

2138

2797

perror_plus("Failed to lower privileges");

2139

2798

}

2140

2799

}

2265

2924

if(ret_errno != 0){

2266

2925

errno = ret_errno;

2267

2926

perror_plus("argz_add");

2927

free(direntries[i]);

2268

2928

continue;

2269

2929

}

2270

2930

if(debug){

2271

2931

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

2272

2932

direntries[i]->d_name);

2273

2933

}

2934

free(direntries[i]);

2274

2935

}

2275

2936

free(direntries);

2276

2937

} else {

2277

free(direntries);

2938

if(ret == 0){

2939

free(direntries);

2940

}

2278

2941

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

2279

2942

exitcode = EXIT_FAILURE;

2280

2943

goto end;

2306

2969

errno = bring_up_interface(interface, delay);

2307

2970

if(not interface_was_up){

2308

2971

if(errno != 0){

2309

perror_plus("Failed to bring up interface");

2972

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

2973

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

2310

2974

} else {

2311

2975

errno = argz_add(&interfaces_to_take_down,

2312

2976

&interfaces_to_take_down_size,

2335

2999

goto end;

2336

3000

}

2337

3001

2338

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

3002

#if GNUTLS_VERSION_NUMBER >= 0x030606

3003

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

3004

#elif GNUTLS_VERSION_NUMBER < 0x030600

3005

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

3006

#else

3007

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

3008

#endif

2339

3009

if(ret == -1){

2340

3010

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

2341

3011

exitcode = EX_UNAVAILABLE;

2463

3133

2464

3134

/* Allocate a new server */

2465

3135

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2466

&config, NULL, NULL, &ret_errno);

3136

&config, NULL, NULL, &ret);

2467

3137

2468

3138

/* Free the Avahi configuration data */

2469

3139

avahi_server_config_free(&config);

2472

3142

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

2473

3143

if(mc.server == NULL){

2474

3144

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

2475

avahi_strerror(ret_errno));

3145

avahi_strerror(ret));

2476

3146

exitcode = EX_UNAVAILABLE;

2477

3147

goto end;

2478

3148

}

2513

3183

end:

2514

3184

2515

3185

if(debug){

2516

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

3186

if(signal_received){

3187

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

3188

argv[0], signal_received,

3189

strsignal(signal_received));

3190

} else {

3191

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

3192

}

2517

3193

}

2518

3194

2519

3195

/* Cleanup things */

2530

3206

2531

3207

if(gnutls_initialized){

2532

3208

gnutls_certificate_free_credentials(mc.cred);

2533

gnutls_global_deinit();

2534

3209

gnutls_dh_params_deinit(mc.dh_params);

2535

3210

}

2536

3211

2544

3219

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

2545

3220

while(mc.current_server != NULL){

2546

3221

server *next = mc.current_server->next;

3222

#ifdef __GNUC__

3223

#pragma GCC diagnostic push

3224

#pragma GCC diagnostic ignored "-Wcast-qual"

3225

#endif

3226

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

3227

#ifdef __GNUC__

3228

#pragma GCC diagnostic pop

3229

#endif

2547

3230

free(mc.current_server);

2548

3231

mc.current_server = next;

2549

3232

}

2551

3234

2552

3235

/* Re-raise privileges */

2553

3236

{

2554

ret_errno = raise_privileges();

2555

if(ret_errno != 0){

3237

ret = raise_privileges();

3238

if(ret != 0){

3239

errno = ret;

2556

3240

perror_plus("Failed to raise privileges");

2557

3241

} else {

2558

3242

2563

3247

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

2564

3248

{

2565

3249

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;

3250

while((interface = argz_next(interfaces_to_take_down,

3251

interfaces_to_take_down_size,

3252

interface))){

3253

ret = take_down_interface(interface);

3254

if(ret != 0){

3255

errno = ret;

2572

3256

perror_plus("Failed to take down interface");

2573

3257

}

2574

3258

}

2579

3263

}

2580

3264

}

2581

3265

2582

ret_errno = lower_privileges_permanently();

2583

if(ret_errno != 0){

3266

ret = lower_privileges_permanently();

3267

if(ret != 0){

3268

errno = ret;

2584

3269

perror_plus("Failed to lower privileges permanently");

2585

3270

}

2586

3271

}

2588

3273

free(interfaces_to_take_down);

2589

3274

free(interfaces_hooks);

2590

3275

3276

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

3277

uintmax_t level){

3278

struct dirent **direntries = NULL;

3279

int dret;

3280

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

3281

O_RDONLY

3282

| O_NOFOLLOW

3283

| O_DIRECTORY

3284

| O_PATH));

3285

if(dir_fd == -1){

3286

perror_plus("open");

3287

return;

3288

}

3289

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

3290

notdotentries, alphasort);

3291

if(numentries >= 0){

3292

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

3293

if(debug){

3294

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

3295

dirname, direntries[i]->d_name);

3296

}

3297

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

3298

if(dret == -1){

3299

if(errno == EISDIR){

3300

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

3301

AT_REMOVEDIR);

3302

}

3303

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

3304

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

3305

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

3306

/* Recurse only in this special case */

3307

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

3308

dret = 0;

3309

}

3310

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

3311

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

3312

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

3313

}

3314

}

3315

free(direntries[i]);

3316

}

3317

3318

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

3319

free(direntries);

3320

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3321

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

3322

perror_plus("rmdir");

3323

}

3324

} else {

3325

perror_plus("scandirat");

3326

}

3327

close(dir_fd);

3328

}

3329

2591

3330

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

2592

3331

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

}

3332

clean_dir_at(-1, tempdir, 0);

2633

3333

}

2634

3334

2635

3335

if(quit_now){