/mandos/release : revision 237.7.166

9

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

10

*

11

* Everything else is

12

13

14

*

15

* This file is part of Mandos.

16

*

17

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

18

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

19

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

20

* (at your option) any later version.

21

*

22

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

12

13

14

*

15

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

16

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

17

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

18

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

19

*

20

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

23

21

* WITHOUT ANY WARRANTY; without even the implied warranty of

24

22

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

25

23

* General Public License for more details.

26

24

*

27

25

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

28

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

26

* along with this program. If not, see

27

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

29

28

*

30

29

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

31

30

*/

33

32

/* Needed by GPGME, specifically gpgme_data_seek() */

34

33

#ifndef _LARGEFILE_SOURCE

35

34

#define _LARGEFILE_SOURCE

36

#endif /* not _LARGEFILE_SOURCE */

35

#endif

37

36

#ifndef _FILE_OFFSET_BITS

38

37

#define _FILE_OFFSET_BITS 64

39

#endif /* not _FILE_OFFSET_BITS */

38

#endif

40

39

41

40

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

42

41

43

42

#include <stdio.h> /* fprintf(), stderr, fwrite(),

44

stdout, ferror() */

43

stdout, ferror(), remove() */

45

44

#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

46

45

#include <stddef.h> /* NULL, size_t, ssize_t */

47

46

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

48

47

strtof(), abort() */

49

48

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

50

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

51

asprintf(), strncpy(), strsignal()

52

*/

49

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

50

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

53

51

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

54

52

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

55

53

sockaddr_in6, PF_INET6,

57

55

opendir(), DIR */

58

56

#include <sys/stat.h> /* open(), S_ISREG */

59

57

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

60

inet_pton(), connect(),

61

getnameinfo() */

62

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

58

inet_pton(), connect() */

59

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

63

60

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

64

61

*/

65

62

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

66

63

strtoimax() */

67

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

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

64

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

72

65

program_invocation_short_name */

73

66

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

74

67

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

79

72

*/

80

73

#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

81

74

getuid(), getgid(), seteuid(),

82

setgid(), pause(), _exit(),

83

unlinkat() */

84

#include <arpa/inet.h> /* inet_pton(), htons() */

75

setgid(), pause(), _exit() */

76

#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */

85

77

#include <iso646.h> /* not, or, and */

86

78

#include <argp.h> /* struct argp_option, error_t, struct

87

79

argp_state, struct argp,

99

91

argz_delete(), argz_append(),

100

92

argz_stringify(), argz_add(),

101

93

argz_count() */

102

#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

103

EAI_SYSTEM, gai_strerror() */

104

94

105

95

#ifdef __linux__

106

96

#include <sys/klog.h> /* klogctl() */

123

113

gnutls_*

124

114

init_gnutls_session(),

125

115

GNUTLS_* */

126

#if GNUTLS_VERSION_NUMBER < 0x030600

127

116

#include <gnutls/openpgp.h>

128

117

/* gnutls_certificate_set_openpgp_key_file(),

129

118

GNUTLS_OPENPGP_FMT_BASE64 */

130

#elif GNUTLS_VERSION_NUMBER >= 0x030606

131

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

132

GNUTLS_PKCS_PLAIN,

133

GNUTLS_PKCS_NULL_PASSWORD */

134

#endif

135

119

136

120

/* GPGME */

137

121

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

145

129

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

146

130

#define SECKEY "seckey.txt"

147

131

#define PUBKEY "pubkey.txt"

148

#define TLS_PRIVKEY "tls-privkey.pem"

149

#define TLS_PUBKEY "tls-pubkey.pem"

150

132

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

151

133

152

134

bool debug = false;

156

138

static const char sys_class_net[] = "/sys/class/net";

157

139

char *connect_to = NULL;

158

140

const char *hookdir = HOOKDIR;

159

int hookdir_fd = -1;

160

141

uid_t uid = 65534;

161

142

gid_t gid = 65534;

162

143

199

180

perror(print_text);

200

181

}

201

182

202

__attribute__((format (gnu_printf, 2, 3), nonnull))

183

__attribute__((format (gnu_printf, 2, 3)))

203

184

int fprintf_plus(FILE *stream, const char *format, ...){

204

185

va_list ap;

205

186

va_start (ap, format);

206

187

207

188

TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

208

189

program_invocation_short_name));

209

return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

190

return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

210

191

}

211

192

212

193

/*

214

195

* bytes. "buffer_capacity" is how much is currently allocated,

215

196

* "buffer_length" is how much is already used.

216

197

*/

217

__attribute__((nonnull, warn_unused_result))

218

198

size_t incbuffer(char **buffer, size_t buffer_length,

219

199

size_t buffer_capacity){

220

200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

221

char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

222

if(new_buf == NULL){

223

int old_errno = errno;

224

free(*buffer);

225

errno = old_errno;

226

*buffer = NULL;

201

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

202

if(buffer == NULL){

227

203

return 0;

228

204

}

229

*buffer = new_buf;

230

205

buffer_capacity += BUFFER_SIZE;

231

206

}

232

207

return buffer_capacity;

233

208

}

234

209

235

210

/* Add server to set of servers to retry periodically */

236

__attribute__((nonnull, warn_unused_result))

237

211

bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

238

212

int af, server **current_server){

239

213

int ret;

248

222

.af = af };

249

223

if(new_server->ip == NULL){

250

224

perror_plus("strdup");

251

free(new_server);

252

return false;

253

}

254

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

255

if(ret == -1){

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);

266

225

return false;

267

226

}

268

227

/* Special case of first server */

270

229

new_server->next = new_server;

271

230

new_server->prev = new_server;

272

231

*current_server = new_server;

232

/* Place the new server last in the list */

273

233

} else {

274

/* Place the new server last in the list */

275

234

new_server->next = *current_server;

276

235

new_server->prev = (*current_server)->prev;

277

236

new_server->prev->next = new_server;

278

237

(*current_server)->prev = new_server;

279

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

280

244

return true;

281

245

}

282

246

283

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

284

__attribute__((warn_unused_result))

285

int raise_privileges(void){

286

int old_errno = errno;

287

int ret = 0;

288

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

289

ret = errno;

290

}

291

errno = old_errno;

292

return ret;

293

}

294

295

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

296

__attribute__((warn_unused_result))

297

int raise_privileges_permanently(void){

298

int old_errno = errno;

299

int ret = raise_privileges();

300

if(ret != 0){

301

errno = old_errno;

302

return ret;

303

}

304

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

305

ret = errno;

306

}

307

errno = old_errno;

308

return ret;

309

}

310

311

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

312

__attribute__((warn_unused_result))

313

int lower_privileges(void){

314

int old_errno = errno;

315

int ret = 0;

316

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

317

ret = errno;

318

}

319

errno = old_errno;

320

return ret;

321

}

322

323

/* Lower privileges permanently */

324

__attribute__((warn_unused_result))

325

int lower_privileges_permanently(void){

326

int old_errno = errno;

327

int ret = 0;

328

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

329

ret = errno;

330

}

331

errno = old_errno;

332

return ret;

333

}

334

335

247

/*

336

248

* Initialize GPGME.

337

249

*/

338

__attribute__((nonnull, warn_unused_result))

339

static bool init_gpgme(const char * const seckey,

340

const char * const pubkey,

341

const char * const tempdir,

342

mandos_context *mc){

250

static bool init_gpgme(const char *seckey, const char *pubkey,

251

const char *tempdir, mandos_context *mc){

343

252

gpgme_error_t rc;

344

253

gpgme_engine_info_t engine_info;

345

254

346

255

/*

347

256

* Helper function to insert pub and seckey to the engine keyring.

348

257

*/

349

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

350

259

int ret;

351

260

int fd;

352

261

gpgme_data_t pgp_data;

357

266

return false;

358

267

}

359

268

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

409

269

rc = gpgme_data_new_from_fd(&pgp_data, fd);

410

270

if(rc != GPG_ERR_NO_ERROR){

411

271

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

419

279

gpgme_strsource(rc), gpgme_strerror(rc));

420

280

return false;

421

281

}

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

}

497

282

498

ret = close(fd);

283

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

499

284

if(ret == -1){

500

285

perror_plus("close");

501

286

}

540

325

/* Create new GPGME "context" */

541

326

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

542

327

if(rc != GPG_ERR_NO_ERROR){

543

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

544

gpgme_strsource(rc), gpgme_strerror(rc));

328

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

329

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

330

gpgme_strerror(rc));

545

331

return false;

546

332

}

547

333

556

342

* Decrypt OpenPGP data.

557

343

* Returns -1 on error

558

344

*/

559

__attribute__((nonnull, warn_unused_result))

560

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

561

346

size_t crypto_size,

562

347

char **plaintext,

583

368

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

584

369

rc = gpgme_data_new(&dh_plain);

585

370

if(rc != GPG_ERR_NO_ERROR){

586

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

371

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

372

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

587

373

gpgme_strsource(rc), gpgme_strerror(rc));

588

374

gpgme_data_release(dh_crypto);

589

375

return -1;

602

388

if(result == NULL){

603

389

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

604

390

} else {

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");

391

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

392

result->unsupported_algorithm);

393

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

394

result->wrong_key_usage);

611

395

if(result->file_name != NULL){

612

396

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

613

397

}

614

615

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

616

r = r->next){

398

gpgme_recipient_t recipient;

399

recipient = result->recipients;

400

while(recipient != NULL){

617

401

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

618

gpgme_pubkey_algo_name(r->pubkey_algo));

619

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

402

gpgme_pubkey_algo_name

403

(recipient->pubkey_algo));

404

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

620

405

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

621

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

406

recipient->status == GPG_ERR_NO_SECKEY

407

? "No" : "Yes");

408

recipient = recipient->next;

622

409

}

623

410

}

624

411

}

680

467

return plaintext_length;

681

468

}

682

469

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

690

__attribute__((warn_unused_result))

691

static const char *safer_gnutls_strerror(int value){

470

static const char * safer_gnutls_strerror(int value){

692

471

const char *ret = gnutls_strerror(value);

693

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

694

475

}

695

476

696

477

/* GnuTLS log function callback */

697

__attribute__((nonnull))

698

478

static void debuggnutls(__attribute__((unused)) int level,

699

479

const char* string){

700

480

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

701

481

}

702

482

703

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

704

483

static int init_gnutls_global(const char *pubkeyfilename,

705

484

const char *seckeyfilename,

706

const char *dhparamsfilename,

707

485

mandos_context *mc){

708

486

int ret;

709

487

711

489

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

712

490

}

713

491

492

ret = gnutls_global_init();

493

if(ret != GNUTLS_E_SUCCESS){

494

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

495

safer_gnutls_strerror(ret));

496

return -1;

497

}

498

714

499

if(debug){

715

500

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

716

501

* - GnuTLS manual

724

509

if(ret != GNUTLS_E_SUCCESS){

725

510

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

726

511

safer_gnutls_strerror(ret));

512

gnutls_global_deinit();

727

513

return -1;

728

514

}

729

515

730

516

if(debug){

731

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

732

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

517

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

518

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

733

519

pubkeyfilename,

734

520

seckeyfilename);

735

521

}

736

522

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

750

523

ret = gnutls_certificate_set_openpgp_key_file

751

524

(mc->cred, pubkeyfilename, seckeyfilename,

752

525

GNUTLS_OPENPGP_FMT_BASE64);

753

#else

754

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

755

#endif

756

526

if(ret != GNUTLS_E_SUCCESS){

757

527

fprintf_plus(stderr,

758

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

528

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

759

529

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

760

530

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

761

531

safer_gnutls_strerror(ret));

770

540

safer_gnutls_strerror(ret));

771

541

goto globalfail;

772

542

}

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

}

543

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

544

if(ret != GNUTLS_E_SUCCESS){

545

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

546

safer_gnutls_strerror(ret));

547

goto globalfail;

548

}

549

550

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

955

551

956

552

return 0;

957

553

958

554

globalfail:

959

555

960

556

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_global_deinit();

961

558

gnutls_dh_params_deinit(mc->dh_params);

962

559

return -1;

963

560

}

964

561

965

__attribute__((nonnull, warn_unused_result))

966

562

static int init_gnutls_session(gnutls_session_t *session,

967

563

mandos_context *mc){

968

564

int ret;

969

565

/* GnuTLS session creation */

970

566

do {

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

));

567

ret = gnutls_init(session, GNUTLS_SERVER);

979

568

if(quit_now){

980

569

return -1;

981

570

}

1022

611

/* ignore client certificate if any. */

1023

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

1024

613

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

1025

616

return 0;

1026

617

}

1027

618

1029

620

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

1030

621

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

1031

622

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

1205

623

/* Called when a Mandos server is found */

1206

__attribute__((nonnull, warn_unused_result))

1207

624

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

1208

625

AvahiIfIndex if_index,

1209

626

int af, mandos_context *mc){

1210

627

int ret, tcp_sd = -1;

1211

628

ssize_t sret;

1212

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1213

633

char *buffer = NULL;

1214

634

char *decrypted_buffer = NULL;

1215

635

size_t buffer_length = 0;

1218

638

int retval = -1;

1219

639

gnutls_session_t session;

1220

640

int pf; /* Protocol family */

1221

bool route_added = false;

1222

641

1223

642

errno = 0;

1224

643

1246

665

bool match = false;

1247

666

{

1248

667

char *interface = NULL;

1249

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

1250

mc->interfaces_size,

1251

interface))){

668

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

669

interface))){

1252

670

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

1253

671

match = true;

1254

672

break;

1283

701

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

1284

702

}

1285

703

1286

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

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1287

705

if(tcp_sd < 0){

1288

706

int e = errno;

1289

707

perror_plus("socket");

1296

714

goto mandos_end;

1297

715

}

1298

716

717

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

1299

718

if(af == AF_INET6){

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);

719

to.in6.sin6_family = (sa_family_t)af;

720

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1303

721

} else { /* IPv4 */

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);

722

to.in.sin_family = (sa_family_t)af;

723

ret = inet_pton(af, ip, &to.in.sin_addr);

1307

724

}

1308

725

if(ret < 0 ){

1309

726

int e = errno;

1318

735

goto mandos_end;

1319

736

}

1320

737

if(af == AF_INET6){

1321

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1322

if(IN6_IS_ADDR_LINKLOCAL

1323

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

741

-Wunreachable-code*/

1324

742

if(if_index == AVAHI_IF_UNSPEC){

1325

743

fprintf_plus(stderr, "An IPv6 link-local address is"

1326

744

" incomplete without a network interface\n");

1328

746

goto mandos_end;

1329

747

}

1330

748

/* Set the network interface number as scope */

1331

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1332

750

}

1333

751

} else {

1334

((struct sockaddr_in *)&to)->sin_port = htons(port);

752

to.in.sin_port = htons(port); /* Spurious warnings from

753

-Wconversion and

754

-Wunreachable-code */

1335

755

}

1336

756

1337

757

if(quit_now){

1354

774

}

1355

775

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1356

776

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1357

if(af == AF_INET6){

1358

ret = getnameinfo((struct sockaddr *)&to,

1359

sizeof(struct sockaddr_in6),

1360

addrstr, sizeof(addrstr), NULL, 0,

1361

NI_NUMERICHOST);

1362

} else {

1363

ret = getnameinfo((struct sockaddr *)&to,

1364

sizeof(struct sockaddr_in),

1365

addrstr, sizeof(addrstr), NULL, 0,

1366

NI_NUMERICHOST);

1367

}

1368

if(ret == EAI_SYSTEM){

1369

perror_plus("getnameinfo");

1370

} else if(ret != 0) {

1371

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1372

} else if(strcmp(addrstr, ip) != 0){

1373

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1374

}

1375

}

1376

1377

if(quit_now){

1378

errno = EINTR;

1379

goto mandos_end;

1380

}

1381

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;

777

const char *pcret;

778

if(af == AF_INET6){

779

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

780

sizeof(addrstr));

781

} else {

782

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

if(strcmp(addrstr, ip) != 0){

789

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

ret = connect(tcp_sd, &to.in6, sizeof(to));

801

} else {

802

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1437

816

}

1438

817

1439

818

const char *out = mandos_protocol_version;

1593

972

&decrypted_buffer, mc);

1594

973

if(decrypted_buffer_size >= 0){

1595

974

1596

clearerr(stdout);

1597

975

written = 0;

1598

976

while(written < (size_t) decrypted_buffer_size){

1599

977

if(quit_now){

1615

993

}

1616

994

written += (size_t)ret;

1617

995

}

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

}

1628

996

retval = 0;

1629

997

}

1630

998

}

1633

1001

1634

1002

mandos_end:

1635

1003

{

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

}

1642

1004

int e = errno;

1643

1005

free(decrypted_buffer);

1644

1006

free(buffer);

1645

1007

if(tcp_sd >= 0){

1646

ret = close(tcp_sd);

1008

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

1647

1009

}

1648

1010

if(ret == -1){

1649

1011

if(e == 0){

1674

1036

AVAHI_GCC_UNUSED AvahiStringList *txt,

1675

1037

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1676

1038

flags,

1677

void *mc){

1039

void* mc){

1678

1040

if(r == NULL){

1679

1041

return;

1680

1042

}

1683

1045

timed out */

1684

1046

1685

1047

if(quit_now){

1686

avahi_s_service_resolver_free(r);

1687

1048

return;

1688

1049

}

1689

1050

1734

1095

const char *domain,

1735

1096

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1736

1097

flags,

1737

void *mc){

1098

void* mc){

1738

1099

if(b == NULL){

1739

1100

return;

1740

1101

}

1800

1161

errno = old_errno;

1801

1162

}

1802

1163

1803

__attribute__((nonnull, warn_unused_result))

1804

1164

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

1805

1165

int ret;

1806

int old_errno;

1166

error_t ret_errno;

1807

1167

1808

1168

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

1809

1169

if(s < 0){

1810

old_errno = errno;

1170

ret_errno = errno;

1811

1171

perror_plus("socket");

1812

errno = old_errno;

1172

errno = ret_errno;

1813

1173

return false;

1814

1174

}

1815

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

1816

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

1175

strcpy(ifr->ifr_name, ifname);

1817

1176

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1818

1177

if(ret == -1){

1819

1178

if(debug){

1820

old_errno = errno;

1179

ret_errno = errno;

1821

1180

perror_plus("ioctl SIOCGIFFLAGS");

1822

errno = old_errno;

1823

}

1824

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

1825

old_errno = errno;

1826

perror_plus("close");

1827

errno = old_errno;

1181

errno = ret_errno;

1828

1182

}

1829

1183

return false;

1830

1184

}

1831

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

1832

old_errno = errno;

1833

perror_plus("close");

1834

errno = old_errno;

1835

}

1836

1185

return true;

1837

1186

}

1838

1187

1839

__attribute__((nonnull, warn_unused_result))

1840

1188

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

1841

1189

1842

1190

/* Reject the loopback device */

1884

1232

* corresponds to an acceptable network device.

1885

1233

* (This function is passed to scandir(3) as a filter function.)

1886

1234

*/

1887

__attribute__((nonnull, warn_unused_result))

1888

1235

int good_interface(const struct dirent *if_entry){

1889

1236

if(if_entry->d_name[0] == '.'){

1890

1237

return 0;

1908

1255

/*

1909

1256

* This function determines if a network interface is up.

1910

1257

*/

1911

__attribute__((nonnull, warn_unused_result))

1912

1258

bool interface_is_up(const char *interface){

1913

1259

struct ifreq ifr;

1914

1260

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

1925

1271

/*

1926

1272

* This function determines if a network interface is running

1927

1273

*/

1928

__attribute__((nonnull, warn_unused_result))

1929

1274

bool interface_is_running(const char *interface){

1930

1275

struct ifreq ifr;

1931

1276

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

1939

1284

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1940

1285

}

1941

1286

1942

__attribute__((nonnull, pure, warn_unused_result))

1943

1287

int notdotentries(const struct dirent *direntry){

1944

1288

/* Skip "." and ".." */

1945

1289

if(direntry->d_name[0] == '.'

1952

1296

}

1953

1297

1954

1298

/* Is this directory entry a runnable program? */

1955

__attribute__((nonnull, warn_unused_result))

1956

1299

int runnable_hook(const struct dirent *direntry){

1957

1300

int ret;

1958

1301

size_t sret;

1966

1309

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

1967

1310

"abcdefghijklmnopqrstuvwxyz"

1968

1311

"0123456789"

1969

"_.-");

1312

"_-");

1970

1313

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

1971

1314

/* Contains non-allowed characters */

1972

1315

if(debug){

1976

1319

return 0;

1977

1320

}

1978

1321

1979

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

1322

char *fullname = NULL;

1323

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1980

1330

if(ret == -1){

1981

1331

if(debug){

1982

1332

perror_plus("Could not stat hook");

2006

1356

return 1;

2007

1357

}

2008

1358

2009

__attribute__((nonnull, warn_unused_result))

2010

1359

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

2011

1360

mandos_context *mc){

2012

1361

int ret;

2016

1365

2017

1366

while(true){

2018

1367

if(mc->current_server == NULL){

2019

if(debug){

1368

if (debug){

2020

1369

fprintf_plus(stderr, "Wait until first server is found."

2021

1370

" No timeout!\n");

2022

1371

}

2023

1372

ret = avahi_simple_poll_iterate(s, -1);

2024

1373

} else {

2025

if(debug){

1374

if (debug){

2026

1375

fprintf_plus(stderr, "Check current_server if we should run"

2027

1376

" it, or wait\n");

2028

1377

}

2045

1394

- ((intmax_t)waited_time.tv_sec * 1000))

2046

1395

- ((intmax_t)waited_time.tv_nsec / 1000000));

2047

1396

2048

if(debug){

1397

if (debug){

2049

1398

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

2050

1399

block_time);

2051

1400

}

2073

1422

ret = avahi_simple_poll_iterate(s, (int)block_time);

2074

1423

}

2075

1424

if(ret != 0){

2076

if(ret > 0 or errno != EINTR){

1425

if (ret > 0 or errno != EINTR){

2077

1426

return (ret != 1) ? ret : 0;

2078

1427

}

2079

1428

}

2080

1429

}

2081

1430

}

2082

1431

2083

__attribute__((nonnull))

2084

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

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

2085

1485

const float delay){

2086

struct dirent **direntries = NULL;

2087

if(hookdir_fd == -1){

2088

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2089

| O_CLOEXEC);

2090

if(hookdir_fd == -1){

2091

if(errno == ENOENT){

2092

if(debug){

2093

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

2094

" found\n", hookdir);

2095

}

2096

} else {

2097

perror_plus("open");

2098

}

2099

return;

2100

}

2101

}

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

}

2107

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

2108

runnable_hook, alphasort);

1486

struct dirent **direntries;

1487

struct dirent *direntry;

1488

int ret;

1489

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

1490

alphasort);

2109

1491

if(numhooks == -1){

2110

perror_plus("scandir");

2111

close(devnull);

2112

return;

2113

}

2114

struct dirent *direntry;

2115

int ret;

2116

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

2117

direntry = direntries[i];

2118

if(debug){

2119

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

2120

direntry->d_name);

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

2121

1499

}

2122

pid_t hook_pid = fork();

2123

if(hook_pid == 0){

2124

/* Child */

2125

/* Raise privileges */

2126

errno = raise_privileges_permanently();

2127

if(errno != 0){

2128

perror_plus("Failed to raise privileges");

2129

_exit(EX_NOPERM);

2130

}

2131

/* Set group */

2132

errno = 0;

2133

ret = setgid(0);

2134

if(ret == -1){

2135

perror_plus("setgid");

2136

_exit(EX_NOPERM);

2137

}

2138

/* Reset supplementary groups */

2139

errno = 0;

2140

ret = setgroups(0, NULL);

2141

if(ret == -1){

2142

perror_plus("setgroups");

2143

_exit(EX_NOPERM);

2144

}

2145

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

2146

if(ret == -1){

2147

perror_plus("setenv");

2148

_exit(EX_OSERR);

2149

}

2150

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

2151

if(ret == -1){

2152

perror_plus("setenv");

2153

_exit(EX_OSERR);

2154

}

2155

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

2156

if(ret == -1){

2157

perror_plus("setenv");

2158

_exit(EX_OSERR);

2159

}

2160

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

2161

if(ret == -1){

2162

perror_plus("setenv");

2163

_exit(EX_OSERR);

2164

}

2165

char *delaystring;

2166

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

2167

if(ret == -1){

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1506

if(ret < 0){

2168

1507

perror_plus("asprintf");

2169

_exit(EX_OSERR);

2170

}

2171

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

2172

if(ret == -1){

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

2173

1566

free(delaystring);

2174

perror_plus("setenv");

2175

_exit(EX_OSERR);

2176

}

2177

free(delaystring);

2178

if(connect_to != NULL){

2179

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

2180

if(ret == -1){

2181

perror_plus("setenv");

2182

_exit(EX_OSERR);

2183

}

2184

}

2185

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

2186

direntry->d_name,

2187

O_RDONLY));

2188

if(hook_fd == -1){

2189

perror_plus("openat");

2190

_exit(EXIT_FAILURE);

2191

}

2192

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

2193

perror_plus("close");

2194

_exit(EXIT_FAILURE);

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

}

2211

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

2212

environ) == -1){

2213

perror_plus("fexecve");

2214

_exit(EXIT_FAILURE);

2215

}

2216

} else {

2217

if(hook_pid == -1){

2218

perror_plus("fork");

2219

free(direntry);

2220

continue;

2221

}

2222

int status;

2223

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

2224

perror_plus("waitpid");

2225

free(direntry);

2226

continue;

2227

}

2228

if(WIFEXITED(status)){

2229

if(WEXITSTATUS(status) != 0){

2230

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

2231

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

2232

WEXITSTATUS(status));

2233

free(direntry);

2234

continue;

2235

}

2236

} else if(WIFSIGNALED(status)){

2237

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

2238

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

2239

WTERMSIG(status));

2240

free(direntry);

2241

continue;

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

2242

1578

} else {

2243

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

2244

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

2245

free(direntry);

2246

continue;

2247

}

2248

}

2249

if(debug){

2250

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

2251

direntry->d_name);

2252

}

2253

free(direntry);

2254

}

2255

free(direntries);

2256

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

2257

perror_plus("close");

2258

} else {

2259

hookdir_fd = -1;

2260

}

2261

close(devnull);

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2262

1615

}

2263

1616

2264

__attribute__((nonnull, warn_unused_result))

2265

int bring_up_interface(const char *const interface,

2266

const float delay){

2267

int old_errno = errno;

2268

int ret;

1617

error_t bring_up_interface(const char *const interface,

1618

const float delay){

1619

int sd = -1;

1620

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2269

1623

struct ifreq network;

2270

1624

unsigned int if_index = if_nametoindex(interface);

2271

1625

if(if_index == 0){

2280

1634

}

2281

1635

2282

1636

if(not interface_is_up(interface)){

2283

int ret_errno = 0;

2284

int ioctl_errno = 0;

2285

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

1637

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

2286

1638

ret_errno = errno;

2287

1639

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

2288

1640

"\"%s\"\n", interface);

2289

errno = old_errno;

2290

1641

return ret_errno;

2291

1642

}

2292

network.ifr_flags |= IFF_UP; /* set flag */

1643

network.ifr_flags |= IFF_UP;

2293

1644

2294

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

2295

if(sd == -1){

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2296

1647

ret_errno = errno;

2297

1648

perror_plus("socket");

2298

1649

errno = old_errno;

2299

1650

return ret_errno;

2300

1651

}

2301

1652

2302

1653

if(quit_now){

2303

ret = close(sd);

2304

if(ret == -1){

2305

perror_plus("close");

2306

}

1654

close(sd);

2307

1655

errno = old_errno;

2308

1656

return EINTR;

2309

1657

}

2313

1661

interface);

2314

1662

}

2315

1663

2316

/* Raise privileges */

2317

ret_errno = raise_privileges();

2318

if(ret_errno != 0){

2319

errno = ret_errno;

2320

perror_plus("Failed to raise privileges");

2321

}

1664

/* Raise priviliges */

1665

raise_privileges();

2322

1666

2323

1667

#ifdef __linux__

2324

int ret_linux;

2325

bool restore_loglevel = false;

2326

if(ret_errno == 0){

2327

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2328

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

2329

ret_linux = klogctl(8, NULL, 5);

2330

if(ret_linux == -1){

2331

perror_plus("klogctl");

2332

} else {

2333

restore_loglevel = true;

2334

}

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

int ret_linux = klogctl(8, NULL, 5);

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2335

1675

}

2336

1676

#endif /* __linux__ */

2337

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

2338

ioctl_errno = errno;

1677

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

1678

ret_errno = errno;

2339

1679

#ifdef __linux__

2340

1680

if(restore_loglevel){

2341

1681

ret_linux = klogctl(7, NULL, 0);

2345

1685

}

2346

1686

#endif /* __linux__ */

2347

1687

2348

/* If raise_privileges() succeeded above */

2349

if(ret_errno == 0){

2350

/* Lower privileges */

2351

ret_errno = lower_privileges();

2352

if(ret_errno != 0){

2353

errno = ret_errno;

2354

perror_plus("Failed to lower privileges");

2355

}

2356

}

1688

/* Lower privileges */

1689

lower_privileges();

2357

1690

2358

1691

/* Close the socket */

2359

ret = close(sd);

1692

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

2360

1693

if(ret == -1){

2361

1694

perror_plus("close");

2362

1695

}

2363

1696

2364

1697

if(ret_setflags == -1){

2365

errno = ioctl_errno;

1698

errno = ret_errno;

2366

1699

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2367

1700

errno = old_errno;

2368

return ioctl_errno;

1701

return ret_errno;

2369

1702

}

2370

1703

} else if(debug){

2371

1704

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

2374

1707

2375

1708

/* Sleep checking until interface is running.

2376

1709

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

2377

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

1710

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

2378

1711

if(interface_is_running(interface)){

2379

1712

break;

2380

1713

}

2389

1722

return 0;

2390

1723

}

2391

1724

2392

__attribute__((nonnull, warn_unused_result))

2393

int take_down_interface(const char *const interface){

2394

int old_errno = errno;

1725

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

2395

1730

struct ifreq network;

2396

1731

unsigned int if_index = if_nametoindex(interface);

2397

1732

if(if_index == 0){

2400

1735

return ENXIO;

2401

1736

}

2402

1737

if(interface_is_up(interface)){

2403

int ret_errno = 0;

2404

int ioctl_errno = 0;

2405

1738

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

2406

1739

ret_errno = errno;

2407

1740

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

2408

1741

"\"%s\"\n", interface);

2409

errno = old_errno;

2410

1742

return ret_errno;

2411

1743

}

2412

1744

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2413

1745

2414

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

2415

if(sd == -1){

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2416

1748

ret_errno = errno;

2417

1749

perror_plus("socket");

2418

1750

errno = old_errno;

2424

1756

interface);

2425

1757

}

2426

1758

2427

/* Raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

2432

}

2433

2434

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

2435

ioctl_errno = errno;

2436

2437

/* If raise_privileges() succeeded above */

2438

if(ret_errno == 0){

2439

/* Lower privileges */

2440

ret_errno = lower_privileges();

2441

if(ret_errno != 0){

2442

errno = ret_errno;

2443

perror_plus("Failed to lower privileges");

2444

}

2445

}

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

2446

1767

2447

1768

/* Close the socket */

2448

int ret = close(sd);

1769

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

2449

1770

if(ret == -1){

2450

1771

perror_plus("close");

2451

1772

}

2452

1773

2453

1774

if(ret_setflags == -1){

2454

errno = ioctl_errno;

1775

errno = ret_errno;

2455

1776

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2456

1777

errno = old_errno;

2457

return ioctl_errno;

1778

return ret_errno;

2458

1779

}

2459

1780

} else if(debug){

2460

1781

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

2466

1787

}

2467

1788

2468

1789

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

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 };

1790

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

1791

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

1792

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

1793

.interfaces = NULL, .interfaces_size = 0 };

2482

1794

AvahiSServiceBrowser *sb = NULL;

2483

1795

error_t ret_errno;

2484

1796

int ret;

2487

1799

int exitcode = EXIT_SUCCESS;

2488

1800

char *interfaces_to_take_down = NULL;

2489

1801

size_t interfaces_to_take_down_size = 0;

2490

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2491

char old_tempdir[] = "/tmp/mandosXXXXXX";

2492

char *tempdir = NULL;

1802

char tempdir[] = "/tmp/mandosXXXXXX";

1803

bool tempdir_created = false;

2493

1804

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2494

1805

const char *seckey = PATHDIR "/" SECKEY;

2495

1806

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;

2501

1807

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

2502

1809

2503

1810

bool gnutls_initialized = false;

2504

1811

bool gpgme_initialized = false;

2550

1857

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

2551

1858

.arg = "FILE",

2552

1859

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

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 },

1860

.group = 2 },

2570

1861

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

2571

1862

.arg = "BITS",

2572

1863

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

2573

1864

" Diffie-Hellman key exchange",

2574

1865

.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 },

2580

1866

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

2581

1867

.arg = "STRING",

2582

1868

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

2628

1914

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

2629

1915

pubkey = arg;

2630

1916

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;

2641

1917

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

2642

1918

errno = 0;

2643

1919

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

2647

1923

}

2648

1924

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

2649

1925

break;

2650

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

2651

dh_params_file = arg;

2652

break;

2653

1926

case 130: /* --priority */

2654

1927

mc.priority = arg;

2655

1928

break;

2678

1951

argp_state_help(state, state->out_stream,

2679

1952

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

2680

1953

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2681

__builtin_unreachable();

2682

1954

case -3: /* --usage */

2683

1955

argp_state_help(state, state->out_stream,

2684

1956

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2685

__builtin_unreachable();

2686

1957

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

2687

1958

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

2688

1959

exit(argp_err_exit_status);

2697

1968

.args_doc = "",

2698

1969

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

2699

1970

" passwords from a Mandos server" };

2700

ret_errno = argp_parse(&argp, argc, argv,

2701

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2702

switch(ret_errno){

1971

ret = argp_parse(&argp, argc, argv,

1972

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1973

switch(ret){

2703

1974

case 0:

2704

1975

break;

2705

1976

case ENOMEM:

2706

1977

default:

2707

errno = ret_errno;

1978

errno = ret;

2708

1979

perror_plus("argp_parse");

2709

1980

exitcode = EX_OSERR;

2710

1981

goto end;

2713

1984

goto end;

2714

1985

}

2715

1986

}

2716

1987

2717

1988

{

2718

1989

/* Work around Debian bug #633582:

2719

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

1990

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

2720

1991

2721

/* Re-raise privileges */

2722

ret = raise_privileges();

2723

if(ret != 0){

2724

errno = ret;

2725

perror_plus("Failed to raise privileges");

2726

} else {

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2727

1994

struct stat st;

2728

1995

2729

1996

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

2743

2010

}

2744

2011

}

2745

2012

}

2746

close(seckey_fd);

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2747

2014

}

2748

2015

}

2749

2016

2750

2017

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

2751

2018

int pubkey_fd = open(pubkey, O_RDONLY);

2752

2019

if(pubkey_fd == -1){

2764

2031

}

2765

2032

}

2766

2033

}

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

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

}

2036

}

2037

2793

2038

/* Lower privileges */

2794

ret = lower_privileges();

2795

if(ret != 0){

2796

errno = ret;

2797

perror_plus("Failed to lower privileges");

2798

}

2039

lower_privileges();

2799

2040

}

2800

2041

}

2801

2042

2825

2066

goto end;

2826

2067

}

2827

2068

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2828

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2829

}

2830

run_network_hooks("start", interfaces_hooks != NULL ?

2831

interfaces_hooks : "", delay);

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2832

2077

}

2833

2078

2834

2079

if(not debug){

2912

2157

2913

2158

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

2914

2159

if(mc.interfaces == NULL){

2915

struct dirent **direntries = NULL;

2160

struct dirent **direntries;

2916

2161

/* Look for any good interfaces */

2917

2162

ret = scandir(sys_class_net, &direntries, good_interface,

2918

2163

alphasort);

2922

2167

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2923

2168

direntries[i]->d_name);

2924

2169

if(ret_errno != 0){

2925

errno = ret_errno;

2926

2170

perror_plus("argz_add");

2927

free(direntries[i]);

2928

2171

continue;

2929

2172

}

2930

2173

if(debug){

2931

2174

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

2932

2175

direntries[i]->d_name);

2933

2176

}

2934

free(direntries[i]);

2935

2177

}

2936

2178

free(direntries);

2937

2179

} else {

2938

if(ret == 0){

2939

free(direntries);

2940

}

2180

free(direntries);

2941

2181

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

2942

2182

exitcode = EXIT_FAILURE;

2943

2183

goto end;

2966

2206

break;

2967

2207

}

2968

2208

bool interface_was_up = interface_is_up(interface);

2969

errno = bring_up_interface(interface, delay);

2209

ret = bring_up_interface(interface, delay);

2970

2210

if(not interface_was_up){

2971

if(errno != 0){

2972

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

2973

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

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2974

2214

} else {

2975

errno = argz_add(&interfaces_to_take_down,

2976

&interfaces_to_take_down_size,

2977

interface);

2978

if(errno != 0){

2979

perror_plus("argz_add");

2980

}

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2981

2218

}

2982

2219

}

2983

2220

}

2999

2236

goto end;

3000

2237

}

3001

2238

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

2239

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

3009

2240

if(ret == -1){

3010

2241

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

3011

2242

exitcode = EX_UNAVAILABLE;

3018

2249

goto end;

3019

2250

}

3020

2251

3021

/* Try /run/tmp before /tmp */

3022

tempdir = mkdtemp(run_tempdir);

3023

if(tempdir == NULL and errno == ENOENT){

3024

if(debug){

3025

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

3026

run_tempdir, old_tempdir);

3027

}

3028

tempdir = mkdtemp(old_tempdir);

3029

}

3030

if(tempdir == NULL){

2252

if(mkdtemp(tempdir) == NULL){

3031

2253

perror_plus("mkdtemp");

3032

2254

goto end;

3033

2255

}

2256

tempdir_created = true;

3034

2257

3035

2258

if(quit_now){

3036

2259

goto end;

3108

2331

fprintf_plus(stderr, "Retrying in %d seconds\n",

3109

2332

(int)retry_interval);

3110

2333

}

3111

sleep((unsigned int)retry_interval);

2334

sleep((int)retry_interval);

3112

2335

}

3113

2336

3114

if(not quit_now){

2337

if (not quit_now){

3115

2338

exitcode = EXIT_SUCCESS;

3116

2339

}

3117

2340

3133

2356

3134

2357

/* Allocate a new server */

3135

2358

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3136

&config, NULL, NULL, &ret);

2359

&config, NULL, NULL, &ret_errno);

3137

2360

3138

2361

/* Free the Avahi configuration data */

3139

2362

avahi_server_config_free(&config);

3142

2365

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

3143

2366

if(mc.server == NULL){

3144

2367

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

3145

avahi_strerror(ret));

2368

avahi_strerror(ret_errno));

3146

2369

exitcode = EX_UNAVAILABLE;

3147

2370

goto end;

3148

2371

}

3172

2395

if(debug){

3173

2396

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

3174

2397

}

3175

2398

3176

2399

ret = avahi_loop_with_timeout(simple_poll,

3177

2400

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

3178

2401

if(debug){

3183

2406

end:

3184

2407

3185

2408

if(debug){

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

}

2409

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

3193

2410

}

3194

2411

3195

2412

/* Cleanup things */

3206

2423

3207

2424

if(gnutls_initialized){

3208

2425

gnutls_certificate_free_credentials(mc.cred);

2426

gnutls_global_deinit();

3209

2427

gnutls_dh_params_deinit(mc.dh_params);

3210

2428

}

3211

2429

3219

2437

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

3220

2438

while(mc.current_server != NULL){

3221

2439

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

3230

2440

free(mc.current_server);

3231

2441

mc.current_server = next;

3232

2442

}

3233

2443

}

3234

2444

3235

/* Re-raise privileges */

2445

/* Re-raise priviliges */

3236

2446

{

3237

ret = raise_privileges();

3238

if(ret != 0){

3239

errno = ret;

3240

perror_plus("Failed to raise privileges");

3241

} else {

3242

3243

/* Run network hooks */

3244

run_network_hooks("stop", interfaces_hooks != NULL ?

3245

interfaces_hooks : "", delay);

3246

3247

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

3248

{

3249

char *interface = NULL;

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;

3256

perror_plus("Failed to take down interface");

3257

}

3258

}

3259

if(debug and (interfaces_to_take_down == NULL)){

3260

fprintf_plus(stderr, "No interfaces needed to be taken"

3261

" down\n");

3262

}

3263

}

3264

}

3265

3266

ret = lower_privileges_permanently();

3267

if(ret != 0){

3268

errno = ret;

3269

perror_plus("Failed to lower privileges permanently");

3270

}

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

if(debug and (interfaces_to_take_down == NULL)){

2466

fprintf_plus(stderr, "No interfaces needed to be taken"

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

3271

2472

}

3272

2473

3273

2474

free(interfaces_to_take_down);

3274

2475

free(interfaces_hooks);

3275

2476

3276

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

3277

uintmax_t level){

2477

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

2478

if(tempdir_created){

3278

2479

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){

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

3292

2484

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

3330

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

3331

if(tempdir != NULL){

3332

clean_dir_at(-1, tempdir, 0);

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

ret = asprintf(&fullname, "%s/%s", tempdir,

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2496

strerror(errno));

2497

}

2498

free(fullname);

2499

}

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

2510

}

3333

2511

}

3334

2512

3335

2513

if(quit_now){