/mandos/release : revision 237.12.2

9

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

10

*

11

* Everything else is

12

13

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

26

* along with this program. If not, see

27

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

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*

29

* Contact the authors at <mandos@fukt.bsnet.se>.

29

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

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

33

34

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

34

37

#define _FILE_OFFSET_BITS 64

38

#endif

35

39

36

40

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

37

41

38

42

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

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

42

45

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

43

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

44

srand() */

46

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

47

strtof(), abort() */

45

48

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

46

49

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

47

50

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

56

59

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

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60

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

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61

*/

59

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

62

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

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strtoimax() */

60

64

#include <assert.h> /* assert() */

61

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

62

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

65

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

66

program_invocation_short_name */

67

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

63

68

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

64

69

SIOCSIFFLAGS, if_indextoname(),

65

70

if_nametoindex(), IF_NAMESIZE */

67

72

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

68

73

*/

69

74

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

70

getuid(), getgid(), setuid(),

71

setgid() */

72

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

75

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

76

setgid(), pause() */

77

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

73

78

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

74

79

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

75

80

argp_state, struct argp,

76

81

argp_parse(), ARGP_KEY_ARG,

77

82

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

83

#include <signal.h> /* sigemptyset(), sigaddset(),

84

sigaction(), SIGTERM, sig_atomic_t,

85

raise() */

86

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

88

78

89

#ifdef __linux__

79

90

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

80

#endif

91

#endif /* __linux__ */

81

92

82

93

/* Avahi */

83

94

/* All Avahi types, constants and functions

116

127

bool debug = false;

117

128

static const char mandos_protocol_version[] = "1";

118

129

const char *argp_program_version = "mandos-client " VERSION;

119

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

130

const char *argp_program_bug_address = "<mandos@recompile.se>";

131

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

132

char *connect_to = NULL;

133

134

/* Doubly linked list that need to be circularly linked when used */

135

typedef struct server{

136

const char *ip;

137

uint16_t port;

138

AvahiIfIndex if_index;

139

int af;

140

struct timespec last_seen;

141

struct server *next;

142

struct server *prev;

143

} server;

120

144

121

145

/* Used for passing in values through the Avahi callback functions */

122

146

typedef struct {

127

151

gnutls_dh_params_t dh_params;

128

152

const char *priority;

129

153

gpgme_ctx_t ctx;

154

server *current_server;

130

155

} mandos_context;

131

156

157

/* global context so signal handler can reach it*/

158

mandos_context mc = { .simple_poll = NULL, .server = NULL,

159

.dh_bits = 1024, .priority = "SECURE256"

160

":!CTYPE-X.509:+CTYPE-OPENPGP",

161

.current_server = NULL };

162

163

sig_atomic_t quit_now = 0;

164

int signal_received = 0;

165

166

/* Function to use when printing errors */

167

void perror_plus(const char *print_text){

168

fprintf(stderr, "Mandos plugin %s: ",

169

program_invocation_short_name);

170

perror(print_text);

171

}

172

132

173

/*

133

* Make room in "buffer" for at least BUFFER_SIZE additional bytes.

134

* "buffer_capacity" is how much is currently allocated,

174

* Make additional room in "buffer" for at least BUFFER_SIZE more

175

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

135

176

* "buffer_length" is how much is already used.

136

177

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

178

size_t incbuffer(char **buffer, size_t buffer_length,

138

179

size_t buffer_capacity){

139

180

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

181

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

146

187

return buffer_capacity;

147

188

}

148

189

190

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

191

int add_server(const char *ip, uint16_t port,

192

AvahiIfIndex if_index,

193

int af){

194

int ret;

195

server *new_server = malloc(sizeof(server));

196

if(new_server == NULL){

197

perror_plus("malloc");

198

return -1;

199

}

200

*new_server = (server){ .ip = strdup(ip),

201

.port = port,

202

.if_index = if_index,

203

.af = af };

204

if(new_server->ip == NULL){

205

perror_plus("strdup");

206

return -1;

207

}

208

/* Special case of first server */

209

if (mc.current_server == NULL){

210

new_server->next = new_server;

211

new_server->prev = new_server;

212

mc.current_server = new_server;

213

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

214

} else {

215

new_server->next = mc.current_server;

216

new_server->prev = mc.current_server->prev;

217

new_server->prev->next = new_server;

218

mc.current_server->prev = new_server;

219

}

220

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

221

if(ret == -1){

222

perror_plus("clock_gettime");

223

return -1;

224

}

225

return 0;

226

}

227

149

228

/*

150

229

* Initialize GPGME.

151

230

*/

152

static bool init_gpgme(mandos_context *mc, const char *seckey,

231

static bool init_gpgme(const char *seckey,

153

232

const char *pubkey, const char *tempdir){

154

int ret;

155

233

gpgme_error_t rc;

156

234

gpgme_engine_info_t engine_info;

157

235

160

238

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

161

239

*/

162

240

bool import_key(const char *filename){

241

int ret;

163

242

int fd;

164

243

gpgme_data_t pgp_data;

165

244

166

245

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

167

246

if(fd == -1){

168

perror("open");

247

perror_plus("open");

169

248

return false;

170

249

}

171

250

176

255

return false;

177

256

}

178

257

179

rc = gpgme_op_import(mc->ctx, pgp_data);

258

rc = gpgme_op_import(mc.ctx, pgp_data);

180

259

if(rc != GPG_ERR_NO_ERROR){

181

260

fprintf(stderr, "bad gpgme_op_import: %s: %s\n",

182

261

gpgme_strsource(rc), gpgme_strerror(rc));

185

264

186

265

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

187

266

if(ret == -1){

188

perror("close");

267

perror_plus("close");

189

268

}

190

269

gpgme_data_release(pgp_data);

191

270

return true;

192

271

}

193

272

194

273

if(debug){

195

fprintf(stderr, "Initialize gpgme\n");

274

fprintf(stderr, "Initializing GPGME\n");

196

275

}

197

276

198

277

/* Init GPGME */

204

283

return false;

205

284

}

206

285

207

/* Set GPGME home directory for the OpenPGP engine only */

286

/* Set GPGME home directory for the OpenPGP engine only */

208

287

rc = gpgme_get_engine_info(&engine_info);

209

288

if(rc != GPG_ERR_NO_ERROR){

210

289

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

225

304

}

226

305

227

306

/* Create new GPGME "context" */

228

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

307

rc = gpgme_new(&(mc.ctx));

229

308

if(rc != GPG_ERR_NO_ERROR){

230

309

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

231

310

gpgme_strsource(rc), gpgme_strerror(rc));

236

315

return false;

237

316

}

238

317

239

return true;

318

return true;

240

319

}

241

320

242

321

/*

243

322

* Decrypt OpenPGP data.

244

323

* Returns -1 on error

245

324

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

325

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

326

size_t crypto_size,

249

327

char **plaintext){

250

328

gpgme_data_t dh_crypto, dh_plain;

277

355

278

356

/* Decrypt data from the cryptotext data buffer to the plaintext

279

357

data buffer */

280

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

358

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

281

359

if(rc != GPG_ERR_NO_ERROR){

282

360

fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",

283

361

gpgme_strsource(rc), gpgme_strerror(rc));

284

362

plaintext_length = -1;

285

363

if(debug){

286

364

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

365

result = gpgme_op_decrypt_result(mc.ctx);

288

366

if(result == NULL){

289

367

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

290

368

} else {

297

375

}

298

376

gpgme_recipient_t recipient;

299

377

recipient = result->recipients;

300

if(recipient){

301

while(recipient != NULL){

302

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

303

gpgme_pubkey_algo_name(recipient->pubkey_algo));

304

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

305

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

306

recipient->status == GPG_ERR_NO_SECKEY

307

? "No" : "Yes");

308

recipient = recipient->next;

309

}

378

while(recipient != NULL){

379

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

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

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

382

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

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

385

recipient = recipient->next;

310

386

}

311

387

}

312

388

}

319

395

320

396

/* Seek back to the beginning of the GPGME plaintext data buffer */

321

397

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

322

perror("gpgme_data_seek");

398

perror_plus("gpgme_data_seek");

323

399

plaintext_length = -1;

324

400

goto decrypt_end;

325

401

}

326

402

327

403

*plaintext = NULL;

328

404

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

405

plaintext_capacity = incbuffer(plaintext,

330

406

(size_t)plaintext_length,

331

407

plaintext_capacity);

332

408

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

409

perror_plus("incbuffer");

334

410

plaintext_length = -1;

335

411

goto decrypt_end;

336

412

}

343

419

break;

344

420

}

345

421

if(ret < 0){

346

perror("gpgme_data_read");

422

perror_plus("gpgme_data_read");

347

423

plaintext_length = -1;

348

424

goto decrypt_end;

349

425

}

382

458

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

383

459

}

384

460

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

461

static int init_gnutls_global(const char *pubkeyfilename,

387

462

const char *seckeyfilename){

388

463

int ret;

389

464

407

482

}

408

483

409

484

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

411

486

if(ret != GNUTLS_E_SUCCESS){

412

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

413

from

414

-Wunreachable-code

415

*/

487

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

416

488

safer_gnutls_strerror(ret));

417

489

gnutls_global_deinit();

418

490

return -1;

425

497

}

426

498

427

499

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

500

(mc.cred, pubkeyfilename, seckeyfilename,

429

501

GNUTLS_OPENPGP_FMT_BASE64);

430

502

if(ret != GNUTLS_E_SUCCESS){

431

503

fprintf(stderr,

437

509

}

438

510

439

511

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

512

ret = gnutls_dh_params_init(&mc.dh_params);

441

513

if(ret != GNUTLS_E_SUCCESS){

442

514

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

443

515

" %s\n", safer_gnutls_strerror(ret));

444

516

goto globalfail;

445

517

}

446

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

518

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

447

519

if(ret != GNUTLS_E_SUCCESS){

448

520

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

449

521

safer_gnutls_strerror(ret));

450

522

goto globalfail;

451

523

}

452

524

453

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

525

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

526

455

527

return 0;

456

528

457

529

globalfail:

458

530

459

gnutls_certificate_free_credentials(mc->cred);

531

gnutls_certificate_free_credentials(mc.cred);

460

532

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

533

gnutls_dh_params_deinit(mc.dh_params);

462

534

return -1;

463

535

}

464

536

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

537

static int init_gnutls_session(gnutls_session_t *session){

467

538

int ret;

468

539

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

540

do {

541

ret = gnutls_init(session, GNUTLS_SERVER);

542

if(quit_now){

543

return -1;

544

}

545

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

470

546

if(ret != GNUTLS_E_SUCCESS){

471

547

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

472

548

safer_gnutls_strerror(ret));

474

550

475

551

{

476

552

const char *err;

477

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

553

do {

554

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

555

if(quit_now){

556

gnutls_deinit(*session);

557

return -1;

558

}

559

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

478

560

if(ret != GNUTLS_E_SUCCESS){

479

561

fprintf(stderr, "Syntax error at: %s\n", err);

480

562

fprintf(stderr, "GnuTLS error: %s\n",

484

566

}

485

567

}

486

568

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

569

do {

570

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

571

mc.cred);

572

if(quit_now){

573

gnutls_deinit(*session);

574

return -1;

575

}

576

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

489

577

if(ret != GNUTLS_E_SUCCESS){

490

578

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

491

579

safer_gnutls_strerror(ret));

494

582

}

495

583

496

584

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

585

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

586

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

588

502

589

return 0;

503

590

}

509

596

/* Called when a Mandos server is found */

510

597

static int start_mandos_communication(const char *ip, uint16_t port,

511

598

AvahiIfIndex if_index,

512

mandos_context *mc, int af){

513

int ret, tcp_sd;

599

int af){

600

int ret, tcp_sd = -1;

514

601

ssize_t sret;

515

602

union {

516

603

struct sockaddr_in in;

517

604

struct sockaddr_in6 in6;

518

605

} to;

519

606

char *buffer = NULL;

520

char *decrypted_buffer;

607

char *decrypted_buffer = NULL;

521

608

size_t buffer_length = 0;

522

609

size_t buffer_capacity = 0;

523

ssize_t decrypted_buffer_size;

524

610

size_t written;

525

int retval = 0;

611

int retval = -1;

526

612

gnutls_session_t session;

527

613

int pf; /* Protocol family */

528

614

615

errno = 0;

616

617

if(quit_now){

618

errno = EINTR;

619

return -1;

620

}

621

529

622

switch(af){

530

623

case AF_INET6:

531

624

pf = PF_INET6;

535

628

break;

536

629

default:

537

630

fprintf(stderr, "Bad address family: %d\n", af);

631

errno = EINVAL;

538

632

return -1;

539

633

}

540

634

541

ret = init_gnutls_session(mc, &session);

635

ret = init_gnutls_session(&session);

542

636

if(ret != 0){

543

637

return -1;

544

638

}

550

644

551

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

552

646

if(tcp_sd < 0){

553

perror("socket");

554

return -1;

647

int e = errno;

648

perror_plus("socket");

649

errno = e;

650

goto mandos_end;

651

}

652

653

if(quit_now){

654

errno = EINTR;

655

goto mandos_end;

555

656

}

556

657

557

658

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

558

659

if(af == AF_INET6){

559

to.in6.sin6_family = (uint16_t)af;

660

to.in6.sin6_family = (sa_family_t)af;

560

661

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

561

662

} else { /* IPv4 */

562

663

to.in.sin_family = (sa_family_t)af;

563

664

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

564

665

}

565

666

if(ret < 0 ){

566

perror("inet_pton");

567

return -1;

667

int e = errno;

668

perror_plus("inet_pton");

669

errno = e;

670

goto mandos_end;

568

671

}

569

672

if(ret == 0){

673

int e = errno;

570

674

fprintf(stderr, "Bad address: %s\n", ip);

571

return -1;

675

errno = e;

676

goto mandos_end;

572

677

}

573

678

if(af == AF_INET6){

574

679

to.in6.sin6_port = htons(port); /* Spurious warnings from

581

686

if(if_index == AVAHI_IF_UNSPEC){

582

687

fprintf(stderr, "An IPv6 link-local address is incomplete"

583

688

" without a network interface\n");

584

return -1;

689

errno = EINVAL;

690

goto mandos_end;

585

691

}

586

692

/* Set the network interface number as scope */

587

693

to.in6.sin6_scope_id = (uint32_t)if_index;

592

698

-Wunreachable-code */

593

699

}

594

700

701

if(quit_now){

702

errno = EINTR;

703

goto mandos_end;

704

}

705

595

706

if(debug){

596

707

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

597

708

char interface[IF_NAMESIZE];

598

709

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

599

perror("if_indextoname");

710

perror_plus("if_indextoname");

600

711

} else {

601

712

fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",

602

713

ip, interface, port);

616

727

sizeof(addrstr));

617

728

}

618

729

if(pcret == NULL){

619

perror("inet_ntop");

730

perror_plus("inet_ntop");

620

731

} else {

621

732

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

622

733

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

624

735

}

625

736

}

626

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

627

743

if(af == AF_INET6){

628

744

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

629

745

} else {

630

746

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

631

747

}

632

748

if(ret < 0){

633

perror("connect");

634

return -1;

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

635

760

}

636

761

637

762

const char *out = mandos_protocol_version;

641

766

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

642

767

out_size - written));

643

768

if(ret == -1){

644

perror("write");

645

retval = -1;

769

int e = errno;

770

perror_plus("write");

771

errno = e;

646

772

goto mandos_end;

647

773

}

648

774

written += (size_t)ret;

656

782

break;

657

783

}

658

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

789

}

659

790

}

660

791

661

792

if(debug){

662

793

fprintf(stderr, "Establishing TLS session with %s\n", ip);

663

794

}

664

795

796

if(quit_now){

797

errno = EINTR;

798

goto mandos_end;

799

}

800

801

/* Spurious warning from -Wint-to-pointer-cast */

665

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

666

803

667

do{

804

if(quit_now){

805

errno = EINTR;

806

goto mandos_end;

807

}

808

809

do {

668

810

ret = gnutls_handshake(session);

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

669

815

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

670

816

671

817

if(ret != GNUTLS_E_SUCCESS){

673

819

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

674

820

gnutls_perror(ret);

675

821

}

676

retval = -1;

822

errno = EPROTO;

677

823

goto mandos_end;

678

824

}

679

825

685

831

}

686

832

687

833

while(true){

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

834

835

if(quit_now){

836

errno = EINTR;

837

goto mandos_end;

838

}

839

840

buffer_capacity = incbuffer(&buffer, buffer_length,

689

841

buffer_capacity);

690

842

if(buffer_capacity == 0){

691

perror("adjustbuffer");

692

retval = -1;

843

int e = errno;

844

perror_plus("incbuffer");

845

errno = e;

846

goto mandos_end;

847

}

848

849

if(quit_now){

850

errno = EINTR;

693

851

goto mandos_end;

694

852

}

695

853

704

862

case GNUTLS_E_AGAIN:

705

863

break;

706

864

case GNUTLS_E_REHANDSHAKE:

707

do{

865

do {

708

866

ret = gnutls_handshake(session);

867

868

if(quit_now){

869

errno = EINTR;

870

goto mandos_end;

871

}

709

872

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

710

873

if(ret < 0){

711

874

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

712

875

gnutls_perror(ret);

713

retval = -1;

876

errno = EPROTO;

714

877

goto mandos_end;

715

878

}

716

879

break;

717

880

default:

718

881

fprintf(stderr, "Unknown error while reading data from"

719

882

" encrypted session with Mandos server\n");

720

retval = -1;

721

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

884

errno = EIO;

722

885

goto mandos_end;

723

886

}

724

887

} else {

730

893

fprintf(stderr, "Closing TLS session\n");

731

894

}

732

895

733

gnutls_bye(session, GNUTLS_SHUT_RDWR);

896

if(quit_now){

897

errno = EINTR;

898

goto mandos_end;

899

}

900

901

do {

902

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

903

if(quit_now){

904

errno = EINTR;

905

goto mandos_end;

906

}

907

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

734

908

735

909

if(buffer_length > 0){

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

910

ssize_t decrypted_buffer_size;

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

737

912

buffer_length,

738

913

&decrypted_buffer);

739

914

if(decrypted_buffer_size >= 0){

915

740

916

written = 0;

741

917

while(written < (size_t) decrypted_buffer_size){

918

if(quit_now){

919

errno = EINTR;

920

goto mandos_end;

921

}

922

742

923

ret = (int)fwrite(decrypted_buffer + written, 1,

743

924

(size_t)decrypted_buffer_size - written,

744

925

stdout);

745

926

if(ret == 0 and ferror(stdout)){

927

int e = errno;

746

928

if(debug){

747

929

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

748

930

strerror(errno));

749

931

}

750

retval = -1;

751

break;

932

errno = e;

933

goto mandos_end;

752

934

}

753

935

written += (size_t)ret;

754

936

}

755

free(decrypted_buffer);

756

} else {

757

retval = -1;

937

retval = 0;

758

938

}

759

} else {

760

retval = -1;

761

939

}

762

940

763

941

/* Shutdown procedure */

764

942

765

943

mandos_end:

766

free(buffer);

767

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

768

if(ret == -1){

769

perror("close");

944

{

945

int e = errno;

946

free(decrypted_buffer);

947

free(buffer);

948

if(tcp_sd >= 0){

949

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

950

}

951

if(ret == -1){

952

if(e == 0){

953

e = errno;

954

}

955

perror_plus("close");

956

}

957

gnutls_deinit(session);

958

errno = e;

959

if(quit_now){

960

errno = EINTR;

961

retval = -1;

962

}

770

963

}

771

gnutls_deinit(session);

772

964

return retval;

773

965

}

774

966

785

977

AVAHI_GCC_UNUSED AvahiStringList *txt,

786

978

AVAHI_GCC_UNUSED AvahiLookupResultFlags

787

979

flags,

788

void* userdata){

789

mandos_context *mc = userdata;

980

AVAHI_GCC_UNUSED void* userdata){

790

981

assert(r);

791

982

792

983

/* Called whenever a service has been resolved successfully or

793

984

timed out */

794

985

986

if(quit_now){

987

return;

988

}

989

795

990

switch(event){

796

991

default:

797

992

case AVAHI_RESOLVER_FAILURE:

798

993

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

799

994

" of type '%s' in domain '%s': %s\n", name, type, domain,

800

avahi_strerror(avahi_server_errno(mc->server)));

995

avahi_strerror(avahi_server_errno(mc.server)));

801

996

break;

802

997

803

998

case AVAHI_RESOLVER_FOUND:

809

1004

PRIdMAX ") on port %" PRIu16 "\n", name, host_name,

810

1005

ip, (intmax_t)interface, port);

811

1006

}

812

int ret = start_mandos_communication(ip, port, interface, mc,

1007

int ret = start_mandos_communication(ip, port, interface,

813

1008

avahi_proto_to_af(proto));

814

1009

if(ret == 0){

815

avahi_simple_poll_quit(mc->simple_poll);

1010

avahi_simple_poll_quit(mc.simple_poll);

1011

} else {

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

816

1014

}

817

1015

}

818

1016

}

828

1026

const char *domain,

829

1027

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

1028

flags,

831

void* userdata){

832

mandos_context *mc = userdata;

1029

AVAHI_GCC_UNUSED void* userdata){

833

1030

assert(b);

834

1031

835

1032

/* Called whenever a new services becomes available on the LAN or

836

1033

is removed from the LAN */

837

1034

1035

if(quit_now){

1036

return;

1037

}

1038

838

1039

switch(event){

839

1040

default:

840

1041

case AVAHI_BROWSER_FAILURE:

841

1042

842

1043

fprintf(stderr, "(Avahi browser) %s\n",

843

avahi_strerror(avahi_server_errno(mc->server)));

844

avahi_simple_poll_quit(mc->simple_poll);

1044

avahi_strerror(avahi_server_errno(mc.server)));

1045

avahi_simple_poll_quit(mc.simple_poll);

845

1046

return;

846

1047

847

1048

case AVAHI_BROWSER_NEW:

850

1051

the callback function is called the Avahi server will free the

851

1052

resolver for us. */

852

1053

853

if(!(avahi_s_service_resolver_new(mc->server, interface,

854

protocol, name, type, domain,

855

AVAHI_PROTO_INET6, 0,

856

resolve_callback, mc)))

1054

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

857

1057

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

858

name, avahi_strerror(avahi_server_errno(mc->server)));

1058

name, avahi_strerror(avahi_server_errno(mc.server)));

859

1059

break;

860

1060

861

1061

case AVAHI_BROWSER_REMOVE:

870

1070

}

871

1071

}

872

1072

1073

/* Signal handler that stops main loop after SIGTERM */

1074

static void handle_sigterm(int sig){

1075

if(quit_now){

1076

return;

1077

}

1078

quit_now = 1;

1079

signal_received = sig;

1080

int old_errno = errno;

1081

/* set main loop to exit */

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1084

}

1085

errno = old_errno;

1086

}

1087

1088

/*

1089

* This function determines if a directory entry in /sys/class/net

1090

* corresponds to an acceptable network device.

1091

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

1092

*/

1093

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

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

1097

return 0;

1098

}

1099

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1113

/* read line from flags_fd */

1114

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1115

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1116

flagstring[(size_t)to_read] = '\0';

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

tmpmax = strtoimax(flagstring, &tmp, 0);

1141

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1144

if(debug){

1145

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1146

flagstring, if_entry->d_name);

1147

}

1148

free(flagstring);

1149

return 0;

1150

}

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1153

/* Reject the loopback device */

1154

if(flags & IFF_LOOPBACK){

1155

if(debug){

1156

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1157

if_entry->d_name);

1158

}

1159

return 0;

1160

}

1161

/* Accept point-to-point devices only if connect_to is specified */

1162

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1163

if(debug){

1164

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1165

if_entry->d_name);

1166

}

1167

return 1;

1168

}

1169

/* Otherwise, reject non-broadcast-capable devices */

1170

if(not (flags & IFF_BROADCAST)){

1171

if(debug){

1172

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1173

if_entry->d_name);

1174

}

1175

return 0;

1176

}

1177

/* Reject non-ARP interfaces (including dummy interfaces) */

1178

if(flags & IFF_NOARP){

1179

if(debug){

1180

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1181

if_entry->d_name);

1182

}

1183

return 0;

1184

}

1185

/* Accept this device */

1186

if(debug){

1187

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1188

if_entry->d_name);

1189

}

1190

return 1;

1191

}

1192

1193

int notdotentries(const struct dirent *direntry){

1194

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

1195

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

1196

and (direntry->d_name[1] == '\0'

1197

or (direntry->d_name[1] == '.'

1198

and direntry->d_name[2] == '\0'))){

1199

return 0;

1200

}

1201

return 1;

1202

}

1203

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1205

int ret;

1206

struct timespec now;

1207

struct timespec waited_time;

1208

intmax_t block_time;

1209

1210

while(true){

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1215

}

1216

ret = avahi_simple_poll_iterate(s, -1);

1217

} else {

1218

if (debug){

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1221

}

1222

/* the current time */

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1224

if(ret == -1){

1225

perror_plus("clock_gettime");

1226

return -1;

1227

}

1228

/* Calculating in ms how long time between now and server

1229

who we visted longest time ago. Now - last seen. */

1230

waited_time.tv_sec = (now.tv_sec

1231

- mc.current_server->last_seen.tv_sec);

1232

waited_time.tv_nsec = (now.tv_nsec

1233

- mc.current_server->last_seen.tv_nsec);

1234

/* total time is 10s/10,000ms.

1235

Converting to s from ms by dividing by 1,000,

1236

and ns to ms by dividing by 1,000,000. */

1237

block_time = ((retry_interval

1238

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

1239

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

1240

1241

if (debug){

1242

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1243

}

1244

1245

if(block_time <= 0){

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

1250

if(ret == 0){

1251

avahi_simple_poll_quit(mc.simple_poll);

1252

return 0;

1253

}

1254

ret = clock_gettime(CLOCK_MONOTONIC,

1255

&mc.current_server->last_seen);

1256

if(ret == -1){

1257

perror_plus("clock_gettime");

1258

return -1;

1259

}

1260

mc.current_server = mc.current_server->next;

1261

block_time = 0; /* Call avahi to find new Mandos

1262

servers, but don't block */

1263

}

1264

1265

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

1266

}

1267

if(ret != 0){

1268

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

1269

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

1270

}

1271

}

1272

}

1273

}

1274

873

1275

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

874

1276

AvahiSServiceBrowser *sb = NULL;

875

1277

int error;

876

1278

int ret;

877

1279

intmax_t tmpmax;

878

int numchars;

1280

char *tmp;

879

1281

int exitcode = EXIT_SUCCESS;

880

const char *interface = "eth0";

1282

const char *interface = "";

881

1283

struct ifreq network;

882

int sd;

1284

int sd = -1;

1285

bool take_down_interface = false;

883

1286

uid_t uid;

884

1287

gid_t gid;

885

char *connect_to = NULL;

886

1288

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

887

1289

bool tempdir_created = false;

888

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

889

1291

const char *seckey = PATHDIR "/" SECKEY;

890

1292

const char *pubkey = PATHDIR "/" PUBKEY;

891

1293

892

mandos_context mc = { .simple_poll = NULL, .server = NULL,

893

.dh_bits = 1024, .priority = "SECURE256"

894

":!CTYPE-X.509:+CTYPE-OPENPGP" };

895

1294

bool gnutls_initialized = false;

896

1295

bool gpgme_initialized = false;

897

double delay = 2.5;

1296

float delay = 2.5f;

1297

double retry_interval = 10; /* 10s between trying a server and

1298

retrying the same server again */

1299

1300

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1301

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1302

1303

uid = getuid();

1304

gid = getgid();

1305

1306

/* Lower any group privileges we might have, just to be safe */

1307

errno = 0;

1308

ret = setgid(gid);

1309

if(ret == -1){

1310

perror_plus("setgid");

1311

}

1312

1313

/* Lower user privileges (temporarily) */

1314

errno = 0;

1315

ret = seteuid(uid);

1316

if(ret == -1){

1317

perror_plus("seteuid");

1318

}

1319

1320

if(quit_now){

1321

goto end;

1322

}

898

1323

899

1324

{

900

1325

struct argp_option options[] = {

930

1355

.arg = "SECONDS",

931

1356

.doc = "Maximum delay to wait for interface startup",

932

1357

.group = 2 },

1358

{ .name = "retry", .key = 132,

1359

.arg = "SECONDS",

1360

.doc = "Retry interval used when denied by the mandos server",

1361

.group = 2 },

1362

/*

1363

* These reproduce what we would get without ARGP_NO_HELP

1364

*/

1365

{ .name = "help", .key = '?',

1366

.doc = "Give this help list", .group = -1 },

1367

{ .name = "usage", .key = -3,

1368

.doc = "Give a short usage message", .group = -1 },

1369

{ .name = "version", .key = 'V',

1370

.doc = "Print program version", .group = -1 },

933

1371

{ .name = NULL }

934

1372

};

935

1373

936

1374

error_t parse_opt(int key, char *arg,

937

1375

struct argp_state *state){

1376

errno = 0;

938

1377

switch(key){

939

1378

case 128: /* --debug */

940

1379

debug = true;

952

1391

pubkey = arg;

953

1392

break;

954

1393

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

955

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

956

if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax

957

or arg[numchars] != '\0'){

958

fprintf(stderr, "Bad number of DH bits\n");

959

exit(EXIT_FAILURE);

1394

errno = 0;

1395

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

1396

if(errno != 0 or tmp == arg or *tmp != '\0'

1397

or tmpmax != (typeof(mc.dh_bits))tmpmax){

1398

argp_error(state, "Bad number of DH bits");

960

1399

}

961

1400

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

962

1401

break;

964

1403

mc.priority = arg;

965

1404

break;

966

1405

case 131: /* --delay */

967

ret = sscanf(arg, "%lf%n", &delay, &numchars);

968

if(ret < 1 or arg[numchars] != '\0'){

969

fprintf(stderr, "Bad delay\n");

970

exit(EXIT_FAILURE);

1406

errno = 0;

1407

delay = strtof(arg, &tmp);

1408

if(errno != 0 or tmp == arg or *tmp != '\0'){

1409

argp_error(state, "Bad delay");

1410

}

1411

case 132: /* --retry */

1412

errno = 0;

1413

retry_interval = strtod(arg, &tmp);

1414

if(errno != 0 or tmp == arg or *tmp != '\0'

1415

or (retry_interval * 1000) > INT_MAX

1416

or retry_interval < 0){

1417

argp_error(state, "Bad retry interval");

971

1418

}

972

1419

break;

973

case ARGP_KEY_ARG:

974

argp_usage(state);

975

case ARGP_KEY_END:

1420

/*

1421

* These reproduce what we would get without ARGP_NO_HELP

1422

*/

1423

case '?': /* --help */

1424

argp_state_help(state, state->out_stream,

1425

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1426

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1427

case -3: /* --usage */

1428

argp_state_help(state, state->out_stream,

1429

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1430

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

1431

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

1432

exit(argp_err_exit_status);

976

1433

break;

977

1434

default:

978

1435

return ARGP_ERR_UNKNOWN;

979

1436

}

980

return 0;

1437

return errno;

981

1438

}

982

1439

983

1440

struct argp argp = { .options = options, .parser = parse_opt,

984

1441

.args_doc = "",

985

1442

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

986

1443

" passwords from a Mandos server" };

987

ret = argp_parse(&argp, argc, argv, 0, 0, NULL);

988

if(ret == ARGP_ERR_UNKNOWN){

989

fprintf(stderr, "Unknown error while parsing arguments\n");

1444

ret = argp_parse(&argp, argc, argv,

1445

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1446

switch(ret){

1447

case 0:

1448

break;

1449

case ENOMEM:

1450

default:

1451

errno = ret;

1452

perror_plus("argp_parse");

1453

exitcode = EX_OSERR;

1454

goto end;

1455

case EINVAL:

1456

exitcode = EX_USAGE;

1457

goto end;

1458

}

1459

}

1460

1461

{

1462

/* Work around Debian bug #633582:

1463

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

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

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

1474

int seckey_fd = open(seckey, O_RDONLY);

1475

if(seckey_fd == -1){

1476

perror_plus("open");

1477

} else {

1478

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

1479

if(ret == -1){

1480

perror_plus("fstat");

1481

} else {

1482

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1483

ret = fchown(seckey_fd, uid, gid);

1484

if(ret == -1){

1485

perror_plus("fchown");

1486

}

1487

}

1488

}

1489

TEMP_FAILURE_RETRY(close(seckey_fd));

1490

}

1491

}

1492

1493

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

1494

int pubkey_fd = open(pubkey, O_RDONLY);

1495

if(pubkey_fd == -1){

1496

perror_plus("open");

1497

} else {

1498

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

1499

if(ret == -1){

1500

perror_plus("fstat");

1501

} else {

1502

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1503

ret = fchown(pubkey_fd, uid, gid);

1504

if(ret == -1){

1505

perror_plus("fchown");

1506

}

1507

}

1508

}

1509

TEMP_FAILURE_RETRY(close(pubkey_fd));

1510

}

1511

}

1512

1513

/* Lower privileges */

1514

errno = 0;

1515

ret = seteuid(uid);

1516

if(ret == -1){

1517

perror_plus("seteuid");

1518

}

1519

}

1520

1521

if(not debug){

1522

avahi_set_log_function(empty_log);

1523

}

1524

1525

if(interface[0] == '\0'){

1526

struct dirent **direntries;

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1528

alphasort);

1529

if(ret >= 1){

1530

/* Pick the first good interface */

1531

interface = strdup(direntries[0]->d_name);

1532

if(debug){

1533

fprintf(stderr, "Using interface \"%s\"\n", interface);

1534

}

1535

if(interface == NULL){

1536

perror_plus("malloc");

1537

free(direntries);

1538

exitcode = EXIT_FAILURE;

1539

goto end;

1540

}

1541

free(direntries);

1542

} else {

1543

free(direntries);

1544

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

990

1545

exitcode = EXIT_FAILURE;

991

1546

goto end;

992

1547

}

993

1548

}

994

1549

1550

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1551

from the signal handler */

1552

/* Initialize the pseudo-RNG for Avahi */

1553

srand((unsigned int) time(NULL));

1554

mc.simple_poll = avahi_simple_poll_new();

1555

if(mc.simple_poll == NULL){

1556

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1557

exitcode = EX_UNAVAILABLE;

1558

goto end;

1559

}

1560

1561

sigemptyset(&sigterm_action.sa_mask);

1562

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1563

if(ret == -1){

1564

perror_plus("sigaddset");

1565

exitcode = EX_OSERR;

1566

goto end;

1567

}

1568

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1569

if(ret == -1){

1570

perror_plus("sigaddset");

1571

exitcode = EX_OSERR;

1572

goto end;

1573

}

1574

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1575

if(ret == -1){

1576

perror_plus("sigaddset");

1577

exitcode = EX_OSERR;

1578

goto end;

1579

}

1580

/* Need to check if the handler is SIG_IGN before handling:

1581

| [[info:libc:Initial Signal Actions]] |

1582

| [[info:libc:Basic Signal Handling]] |

1583

*/

1584

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1585

if(ret == -1){

1586

perror_plus("sigaction");

1587

return EX_OSERR;

1588

}

1589

if(old_sigterm_action.sa_handler != SIG_IGN){

1590

ret = sigaction(SIGINT, &sigterm_action, NULL);

1591

if(ret == -1){

1592

perror_plus("sigaction");

1593

exitcode = EX_OSERR;

1594

goto end;

1595

}

1596

}

1597

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1598

if(ret == -1){

1599

perror_plus("sigaction");

1600

return EX_OSERR;

1601

}

1602

if(old_sigterm_action.sa_handler != SIG_IGN){

1603

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1604

if(ret == -1){

1605

perror_plus("sigaction");

1606

exitcode = EX_OSERR;

1607

goto end;

1608

}

1609

}

1610

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1611

if(ret == -1){

1612

perror_plus("sigaction");

1613

return EX_OSERR;

1614

}

1615

if(old_sigterm_action.sa_handler != SIG_IGN){

1616

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1617

if(ret == -1){

1618

perror_plus("sigaction");

1619

exitcode = EX_OSERR;

1620

goto end;

1621

}

1622

}

1623

995

1624

/* If the interface is down, bring it up */

996

if(interface[0] != '\0'){

1625

if(strcmp(interface, "none") != 0){

1626

if_index = (AvahiIfIndex) if_nametoindex(interface);

1627

if(if_index == 0){

1628

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1629

exitcode = EX_UNAVAILABLE;

1630

goto end;

1631

}

1632

1633

if(quit_now){

1634

goto end;

1635

}

1636

1637

/* Re-raise priviliges */

1638

errno = 0;

1639

ret = seteuid(0);

1640

if(ret == -1){

1641

perror_plus("seteuid");

1642

}

1643

997

1644

#ifdef __linux__

998

1645

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

999

messages to mess up the prompt */

1646

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

1000

1647

ret = klogctl(8, NULL, 5);

1001

1648

bool restore_loglevel = true;

1002

1649

if(ret == -1){

1003

1650

restore_loglevel = false;

1004

perror("klogctl");

1651

perror_plus("klogctl");

1005

1652

}

1006

#endif

1653

#endif /* __linux__ */

1007

1654

1008

1655

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1009

1656

if(sd < 0){

1010

perror("socket");

1011

exitcode = EXIT_FAILURE;

1657

perror_plus("socket");

1658

exitcode = EX_OSERR;

1012

1659

#ifdef __linux__

1013

1660

if(restore_loglevel){

1014

1661

ret = klogctl(7, NULL, 0);

1015

1662

if(ret == -1){

1016

perror("klogctl");

1663

perror_plus("klogctl");

1017

1664

}

1018

1665

}

1019

#endif

1666

#endif /* __linux__ */

1667

/* Lower privileges */

1668

errno = 0;

1669

ret = seteuid(uid);

1670

if(ret == -1){

1671

perror_plus("seteuid");

1672

}

1020

1673

goto end;

1021

1674

}

1022

1675

strcpy(network.ifr_name, interface);

1023

1676

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1024

1677

if(ret == -1){

1025

perror("ioctl SIOCGIFFLAGS");

1678

perror_plus("ioctl SIOCGIFFLAGS");

1026

1679

#ifdef __linux__

1027

1680

if(restore_loglevel){

1028

1681

ret = klogctl(7, NULL, 0);

1029

1682

if(ret == -1){

1030

perror("klogctl");

1683

perror_plus("klogctl");

1031

1684

}

1032

1685

}

1033

#endif

1034

exitcode = EXIT_FAILURE;

1686

#endif /* __linux__ */

1687

exitcode = EX_OSERR;

1688

/* Lower privileges */

1689

errno = 0;

1690

ret = seteuid(uid);

1691

if(ret == -1){

1692

perror_plus("seteuid");

1693

}

1035

1694

goto end;

1036

1695

}

1037

1696

if((network.ifr_flags & IFF_UP) == 0){

1038

1697

network.ifr_flags |= IFF_UP;

1698

take_down_interface = true;

1039

1699

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

1040

1700

if(ret == -1){

1041

perror("ioctl SIOCSIFFLAGS");

1042

exitcode = EXIT_FAILURE;

1701

take_down_interface = false;

1702

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1703

exitcode = EX_OSERR;

1043

1704

#ifdef __linux__

1044

1705

if(restore_loglevel){

1045

1706

ret = klogctl(7, NULL, 0);

1046

1707

if(ret == -1){

1047

perror("klogctl");

1708

perror_plus("klogctl");

1048

1709

}

1049

1710

}

1050

#endif

1711

#endif /* __linux__ */

1712

/* Lower privileges */

1713

errno = 0;

1714

ret = seteuid(uid);

1715

if(ret == -1){

1716

perror_plus("seteuid");

1717

}

1051

1718

goto end;

1052

1719

}

1053

1720

}

1054

/* sleep checking until interface is running */

1721

/* Sleep checking until interface is running.

1722

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

1055

1723

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

1056

1724

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1057

1725

if(ret == -1){

1058

perror("ioctl SIOCGIFFLAGS");

1726

perror_plus("ioctl SIOCGIFFLAGS");

1059

1727

} else if(network.ifr_flags & IFF_RUNNING){

1060

1728

break;

1061

1729

}

1062

1730

struct timespec sleeptime = { .tv_nsec = 250000000 };

1063

1731

ret = nanosleep(&sleeptime, NULL);

1064

1732

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

1065

perror("nanosleep");

1733

perror_plus("nanosleep");

1066

1734

}

1067

1735

}

1068

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

1069

if(ret == -1){

1070

perror("close");

1736

if(not take_down_interface){

1737

/* We won't need the socket anymore */

1738

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

1739

if(ret == -1){

1740

perror_plus("close");

1741

}

1071

1742

}

1072

1743

#ifdef __linux__

1073

1744

if(restore_loglevel){

1074

1745

/* Restores kernel loglevel to default */

1075

1746

ret = klogctl(7, NULL, 0);

1076

1747

if(ret == -1){

1077

perror("klogctl");

1078

}

1079

}

1080

#endif

1081

}

1082

1083

uid = getuid();

1084

gid = getgid();

1085

1086

errno = 0;

1087

setgid(gid);

1088

if(ret == -1){

1089

perror("setgid");

1090

}

1091

1092

ret = setuid(uid);

1093

if(ret == -1){

1094

perror("setuid");

1095

}

1096

1097

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

1748

perror_plus("klogctl");

1749

}

1750

}

1751

#endif /* __linux__ */

1752

/* Lower privileges */

1753

errno = 0;

1754

if(take_down_interface){

1755

/* Lower privileges */

1756

ret = seteuid(uid);

1757

if(ret == -1){

1758

perror_plus("seteuid");

1759

}

1760

} else {

1761

/* Lower privileges permanently */

1762

ret = setuid(uid);

1763

if(ret == -1){

1764

perror_plus("setuid");

1765

}

1766

}

1767

}

1768

1769

if(quit_now){

1770

goto end;

1771

}

1772

1773

ret = init_gnutls_global(pubkey, seckey);

1098

1774

if(ret == -1){

1099

1775

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

1100

exitcode = EXIT_FAILURE;

1776

exitcode = EX_UNAVAILABLE;

1101

1777

goto end;

1102

1778

} else {

1103

1779

gnutls_initialized = true;

1104

1780

}

1105

1781

1782

if(quit_now){

1783

goto end;

1784

}

1785

1106

1786

if(mkdtemp(tempdir) == NULL){

1107

perror("mkdtemp");

1787

perror_plus("mkdtemp");

1108

1788

goto end;

1109

1789

}

1110

1790

tempdir_created = true;

1111

1791

1112

if(not init_gpgme(&mc, pubkey, seckey, tempdir)){

1792

if(quit_now){

1793

goto end;

1794

}

1795

1796

if(not init_gpgme(pubkey, seckey, tempdir)){

1113

1797

fprintf(stderr, "init_gpgme failed\n");

1114

exitcode = EXIT_FAILURE;

1798

exitcode = EX_UNAVAILABLE;

1115

1799

goto end;

1116

1800

} else {

1117

1801

gpgme_initialized = true;

1118

1802

}

1119

1803

1120

if(interface[0] != '\0'){

1121

if_index = (AvahiIfIndex) if_nametoindex(interface);

1122

if(if_index == 0){

1123

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1124

exitcode = EXIT_FAILURE;

1125

goto end;

1126

}

1804

if(quit_now){

1805

goto end;

1127

1806

}

1128

1807

1129

1808

if(connect_to != NULL){

1132

1811

char *address = strrchr(connect_to, ':');

1133

1812

if(address == NULL){

1134

1813

fprintf(stderr, "No colon in address\n");

1135

exitcode = EXIT_FAILURE;

1136

goto end;

1137

}

1814

exitcode = EX_USAGE;

1815

goto end;

1816

}

1817

1818

if(quit_now){

1819

goto end;

1820

}

1821

1138

1822

uint16_t port;

1139

ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);

1140

if(ret < 1 or tmpmax != (uint16_t)tmpmax

1141

or address[numchars+1] != '\0'){

1823

errno = 0;

1824

tmpmax = strtoimax(address+1, &tmp, 10);

1825

if(errno != 0 or tmp == address+1 or *tmp != '\0'

1826

or tmpmax != (uint16_t)tmpmax){

1142

1827

fprintf(stderr, "Bad port number\n");

1143

exitcode = EXIT_FAILURE;

1144

goto end;

1145

}

1828

exitcode = EX_USAGE;

1829

goto end;

1830

}

1831

1832

if(quit_now){

1833

goto end;

1834

}

1835

1146

1836

port = (uint16_t)tmpmax;

1147

1837

*address = '\0';

1148

address = connect_to;

1149

1838

/* Colon in address indicates IPv6 */

1150

1839

int af;

1151

if(strchr(address, ':') != NULL){

1840

if(strchr(connect_to, ':') != NULL){

1152

1841

af = AF_INET6;

1842

/* Accept [] around IPv6 address - see RFC 5952 */

1843

if(connect_to[0] == '[' and address[-1] == ']')

1844

{

1845

connect_to++;

1846

address[-1] = '\0';

1847

}

1153

1848

} else {

1154

1849

af = AF_INET;

1155

1850

}

1156

ret = start_mandos_communication(address, port, if_index, &mc,

1157

af);

1158

if(ret < 0){

1159

exitcode = EXIT_FAILURE;

1160

} else {

1851

address = connect_to;

1852

1853

if(quit_now){

1854

goto end;

1855

}

1856

1857

while(not quit_now){

1858

ret = start_mandos_communication(address, port, if_index, af);

1859

if(quit_now or ret == 0){

1860

break;

1861

}

1862

if(debug){

1863

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

1864

(int)retry_interval);

1865

}

1866

sleep((int)retry_interval);

1867

}

1868

1869

if (not quit_now){

1161

1870

exitcode = EXIT_SUCCESS;

1162

1871

}

1872

1163

1873

goto end;

1164

1874

}

1165

1875

1166

if(not debug){

1167

avahi_set_log_function(empty_log);

1168

}

1169

1170

/* Initialize the pseudo-RNG for Avahi */

1171

srand((unsigned int) time(NULL));

1172

1173

/* Allocate main Avahi loop object */

1174

mc.simple_poll = avahi_simple_poll_new();

1175

if(mc.simple_poll == NULL){

1176

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1177

exitcode = EXIT_FAILURE;

1876

if(quit_now){

1178

1877

goto end;

1179

1878

}

1180

1879

1200

1899

if(mc.server == NULL){

1201

1900

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

1202

1901

avahi_strerror(error));

1203

exitcode = EXIT_FAILURE;

1902

exitcode = EX_UNAVAILABLE;

1903

goto end;

1904

}

1905

1906

if(quit_now){

1204

1907

goto end;

1205

1908

}

1206

1909

1207

1910

/* Create the Avahi service browser */

1208

1911

sb = avahi_s_service_browser_new(mc.server, if_index,

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1210

NULL, 0, browse_callback, &mc);

1912

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1913

NULL, 0, browse_callback, NULL);

1211

1914

if(sb == NULL){

1212

1915

fprintf(stderr, "Failed to create service browser: %s\n",

1213

1916

avahi_strerror(avahi_server_errno(mc.server)));

1214

exitcode = EXIT_FAILURE;

1917

exitcode = EX_UNAVAILABLE;

1918

goto end;

1919

}

1920

1921

if(quit_now){

1215

1922

goto end;

1216

1923

}

1217

1924

1220

1927

if(debug){

1221

1928

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

1222

1929

}

1223

1224

avahi_simple_poll_loop(mc.simple_poll);

1930

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

1932

(int)(retry_interval * 1000));

1933

if(debug){

1934

fprintf(stderr, "avahi_loop_with_timeout exited %s\n",

1935

(ret == 0) ? "successfully" : "with error");

1936

}

1225

1937

1226

1938

end:

1227

1939

1248

1960

if(gpgme_initialized){

1249

1961

gpgme_release(mc.ctx);

1250

1962

}

1251

1252

/* Removes the temp directory used by GPGME */

1963

1964

/* Cleans up the circular linked list of Mandos servers the client

1965

has seen */

1966

if(mc.current_server != NULL){

1967

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

1968

while(mc.current_server != NULL){

1969

server *next = mc.current_server->next;

1970

free(mc.current_server);

1971

mc.current_server = next;

1972

}

1973

}

1974

1975

/* Take down the network interface */

1976

if(take_down_interface){

1977

/* Re-raise priviliges */

1978

errno = 0;

1979

ret = seteuid(0);

1980

if(ret == -1){

1981

perror_plus("seteuid");

1982

}

1983

if(geteuid() == 0){

1984

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1985

if(ret == -1){

1986

perror_plus("ioctl SIOCGIFFLAGS");

1987

} else if(network.ifr_flags & IFF_UP) {

1988

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

1989

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

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1992

}

1993

}

1994

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

1995

if(ret == -1){

1996

perror_plus("close");

1997

}

1998

/* Lower privileges permanently */

1999

errno = 0;

2000

ret = setuid(uid);

2001

if(ret == -1){

2002

perror_plus("setuid");

2003

}

2004

}

2005

}

2006

2007

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

1253

2008

if(tempdir_created){

1254

DIR *d;

1255

struct dirent *direntry;

1256

d = opendir(tempdir);

1257

if(d == NULL){

1258

if(errno != ENOENT){

1259

perror("opendir");

1260

}

1261

} else {

1262

while(true){

1263

direntry = readdir(d);

1264

if(direntry == NULL){

1265

break;

1266

}

1267

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

1268

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

1269

and (direntry->d_name[1] == '\0'

1270

or (direntry->d_name[1] == '.'

1271

and direntry->d_name[2] == '\0'))){

1272

continue;

1273

}

2009

struct dirent **direntries = NULL;

2010

struct dirent *direntry = NULL;

2011

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

2012

alphasort);

2013

if (numentries > 0){

2014

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

2015

direntry = direntries[i];

1274

2016

char *fullname = NULL;

1275

2017

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

1276

2018

direntry->d_name);

1277

2019

if(ret < 0){

1278

perror("asprintf");

2020

perror_plus("asprintf");

1279

2021

continue;

1280

2022

}

1281

2023

ret = remove(fullname);

1285

2027

}

1286

2028

free(fullname);

1287

2029

}

1288

closedir(d);

2030

}

2031

2032

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

2033

free(direntries);

2034

if (numentries == -1){

2035

perror_plus("scandir");

1289

2036

}

1290

2037

ret = rmdir(tempdir);

1291

2038

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

1292

perror("rmdir");

1293

}

2039

perror_plus("rmdir");

2040

}

2041

}

2042

2043

if(quit_now){

2044

sigemptyset(&old_sigterm_action.sa_mask);

2045

old_sigterm_action.sa_handler = SIG_DFL;

2046

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

2047

&old_sigterm_action,

2048

NULL));

2049

if(ret == -1){

2050

perror_plus("sigaction");

2051

}

2052

do {

2053

ret = raise(signal_received);

2054

} while(ret != 0 and errno == EINTR);

2055

if(ret != 0){

2056

perror_plus("raise");

2057

abort();

2058

}

2059

TEMP_FAILURE_RETRY(pause());

1294

2060

}

1295

2061

1296

2062

return exitcode;