/mandos/trunk : revision 371

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

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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() */

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41

38

42

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

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stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

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45

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

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46

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

44

srand() */

45

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

47

srand(), strtof() */

48

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

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49

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

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50

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

48

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

51

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

49

52

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

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53

sockaddr_in6, PF_INET6,

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SOCK_STREAM, INET6_ADDRSTRLEN,

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uid_t, gid_t, open(), opendir(),

53

DIR */

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SOCK_STREAM, uid_t, gid_t, open(),

55

opendir(), DIR */

54

56

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

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57

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

56

struct in6_addr, inet_pton(),

57

connect() */

58

inet_pton(), connect() */

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

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60

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

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61

*/

61

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

62

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

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strtoimax() */

62

64

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

63

65

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

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66

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

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67

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

66

68

SIOCSIFFLAGS, if_indextoname(),

67

69

if_nametoindex(), IF_NAMESIZE */

68

#include <netinet/in.h>

70

#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,

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INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

69

73

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

70

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

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

71

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setgid() */

72

76

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

73

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

77

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

74

78

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

75

79

argp_state, struct argp,

76

80

argp_parse(), ARGP_KEY_ARG,

77

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

78

86

#ifdef __linux__

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87

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

80

#endif

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#endif /* __linux__ */

81

89

82

90

/* Avahi */

83

91

/* All Avahi types, constants and functions

129

137

gpgme_ctx_t ctx;

130

138

} mandos_context;

131

139

140

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

141

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

142

.dh_bits = 1024, .priority = "SECURE256"

143

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

144

145

sig_atomic_t quit_now = 0;

146

int signal_received = 0;

147

132

148

/*

133

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

134

* "buffer_capacity" is how much is currently allocated,

149

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

150

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

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151

* "buffer_length" is how much is already used.

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152

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

153

size_t incbuffer(char **buffer, size_t buffer_length,

138

154

size_t buffer_capacity){

139

155

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

156

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

149

165

/*

150

166

* Initialize GPGME.

151

167

*/

152

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

168

static bool init_gpgme(const char *seckey,

153

169

const char *pubkey, const char *tempdir){

154

int ret;

155

170

gpgme_error_t rc;

156

171

gpgme_engine_info_t engine_info;

157

172

160

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

161

176

*/

162

177

bool import_key(const char *filename){

178

int ret;

163

179

int fd;

164

180

gpgme_data_t pgp_data;

165

181

176

192

return false;

177

193

}

178

194

179

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

195

rc = gpgme_op_import(mc.ctx, pgp_data);

180

196

if(rc != GPG_ERR_NO_ERROR){

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197

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

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198

gpgme_strsource(rc), gpgme_strerror(rc));

192

208

}

193

209

194

210

if(debug){

195

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

211

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

196

212

}

197

213

198

214

/* Init GPGME */

225

241

}

226

242

227

243

/* Create new GPGME "context" */

228

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

244

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

229

245

if(rc != GPG_ERR_NO_ERROR){

230

246

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

231

247

gpgme_strsource(rc), gpgme_strerror(rc));

236

252

return false;

237

253

}

238

254

239

return true;

255

return true;

240

256

}

241

257

242

258

/*

243

259

* Decrypt OpenPGP data.

244

260

* Returns -1 on error

245

261

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

262

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

263

size_t crypto_size,

249

264

char **plaintext){

250

265

gpgme_data_t dh_crypto, dh_plain;

277

292

278

293

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

279

294

data buffer */

280

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

295

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

281

296

if(rc != GPG_ERR_NO_ERROR){

282

297

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

283

298

gpgme_strsource(rc), gpgme_strerror(rc));

284

299

plaintext_length = -1;

285

300

if(debug){

286

301

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

302

result = gpgme_op_decrypt_result(mc.ctx);

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if(result == NULL){

289

304

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

290

305

} else {

297

312

}

298

313

gpgme_recipient_t recipient;

299

314

recipient = result->recipients;

300

if(recipient){

301

while(recipient != NULL){

302

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

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gpgme_pubkey_algo_name(recipient->pubkey_algo));

304

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

305

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

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recipient->status == GPG_ERR_NO_SECKEY

307

? "No" : "Yes");

308

recipient = recipient->next;

309

}

315

while(recipient != NULL){

316

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

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gpgme_pubkey_algo_name(recipient->pubkey_algo));

318

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

319

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

320

recipient->status == GPG_ERR_NO_SECKEY

321

? "No" : "Yes");

322

recipient = recipient->next;

310

323

}

311

324

}

312

325

}

326

339

327

340

*plaintext = NULL;

328

341

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

342

plaintext_capacity = incbuffer(plaintext,

330

343

(size_t)plaintext_length,

331

344

plaintext_capacity);

332

345

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

346

perror("incbuffer");

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347

plaintext_length = -1;

335

348

goto decrypt_end;

336

349

}

382

395

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

383

396

}

384

397

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

398

static int init_gnutls_global(const char *pubkeyfilename,

387

399

const char *seckeyfilename){

388

400

int ret;

389

401

407

419

}

408

420

409

421

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

422

gnutls_certificate_allocate_credentials(&mc.cred);

411

423

if(ret != GNUTLS_E_SUCCESS){

412

424

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

413

* from

414

* -Wunreachable-code

415

*/

425

from

426

-Wunreachable-code

427

*/

416

428

safer_gnutls_strerror(ret));

417

429

gnutls_global_deinit();

418

430

return -1;

425

437

}

426

438

427

439

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

440

(mc.cred, pubkeyfilename, seckeyfilename,

429

441

GNUTLS_OPENPGP_FMT_BASE64);

430

442

if(ret != GNUTLS_E_SUCCESS){

431

443

fprintf(stderr,

437

449

}

438

450

439

451

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

452

ret = gnutls_dh_params_init(&mc.dh_params);

441

453

if(ret != GNUTLS_E_SUCCESS){

442

454

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

443

455

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

444

456

goto globalfail;

445

457

}

446

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

458

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

447

459

if(ret != GNUTLS_E_SUCCESS){

448

460

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

449

461

safer_gnutls_strerror(ret));

450

462

goto globalfail;

451

463

}

452

464

453

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

465

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

466

455

467

return 0;

456

468

457

469

globalfail:

458

470

459

gnutls_certificate_free_credentials(mc->cred);

471

gnutls_certificate_free_credentials(mc.cred);

460

472

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

473

gnutls_dh_params_deinit(mc.dh_params);

462

474

return -1;

463

475

}

464

476

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

477

static int init_gnutls_session(gnutls_session_t *session){

467

478

int ret;

468

479

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

480

do {

481

ret = gnutls_init(session, GNUTLS_SERVER);

482

if(quit_now){

483

return -1;

484

}

485

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

470

486

if(ret != GNUTLS_E_SUCCESS){

471

487

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

472

488

safer_gnutls_strerror(ret));

474

490

475

491

{

476

492

const char *err;

477

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

493

do {

494

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

495

if(quit_now){

496

gnutls_deinit(*session);

497

return -1;

498

}

499

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

478

500

if(ret != GNUTLS_E_SUCCESS){

479

501

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

480

502

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

484

506

}

485

507

}

486

508

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

509

do {

510

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

511

mc.cred);

512

if(quit_now){

513

gnutls_deinit(*session);

514

return -1;

515

}

516

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

489

517

if(ret != GNUTLS_E_SUCCESS){

490

518

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

491

519

safer_gnutls_strerror(ret));

494

522

}

495

523

496

524

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

525

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

526

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

527

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

528

502

529

return 0;

503

530

}

509

536

/* Called when a Mandos server is found */

510

537

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

511

538

AvahiIfIndex if_index,

512

mandos_context *mc){

513

int ret, tcp_sd;

539

int af){

540

int ret, tcp_sd = -1;

514

541

ssize_t sret;

515

union { struct sockaddr in; struct sockaddr_in6 in6; } to;

542

union {

543

struct sockaddr_in in;

544

struct sockaddr_in6 in6;

545

} to;

516

546

char *buffer = NULL;

517

547

char *decrypted_buffer;

518

548

size_t buffer_length = 0;

519

549

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

521

550

size_t written;

522

551

int retval = 0;

523

char interface[IF_NAMESIZE];

524

552

gnutls_session_t session;

525

526

ret = init_gnutls_session(mc, &session);

553

int pf; /* Protocol family */

554

555

if(quit_now){

556

return -1;

557

}

558

559

switch(af){

560

case AF_INET6:

561

pf = PF_INET6;

562

break;

563

case AF_INET:

564

pf = PF_INET;

565

break;

566

default:

567

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

568

return -1;

569

}

570

571

ret = init_gnutls_session(&session);

527

572

if(ret != 0){

528

573

return -1;

529

574

}

530

575

531

576

if(debug){

532

fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16

577

fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16

533

578

"\n", ip, port);

534

579

}

535

580

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

581

tcp_sd = socket(pf, SOCK_STREAM, 0);

537

582

if(tcp_sd < 0){

538

583

perror("socket");

539

return -1;

584

retval = -1;

585

goto mandos_end;

540

586

}

541

587

542

if(debug){

543

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

544

perror("if_indextoname");

545

return -1;

546

}

547

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

588

if(quit_now){

589

retval = -1;

590

goto mandos_end;

548

591

}

549

592

550

593

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

551

to.in6.sin6_family = AF_INET6;

552

/* It would be nice to have a way to detect if we were passed an

553

IPv4 address here. Now we assume an IPv6 address. */

554

ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);

594

if(af == AF_INET6){

595

to.in6.sin6_family = (sa_family_t)af;

596

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

597

} else { /* IPv4 */

598

to.in.sin_family = (sa_family_t)af;

599

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

600

}

555

601

if(ret < 0 ){

556

602

perror("inet_pton");

557

return -1;

603

retval = -1;

604

goto mandos_end;

558

605

}

559

606

if(ret == 0){

560

607

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

561

return -1;

608

retval = -1;

609

goto mandos_end;

562

610

}

563

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

611

if(af == AF_INET6){

612

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

613

-Wconversion and

614

-Wunreachable-code */

615

616

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

617

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

618

-Wunreachable-code*/

619

if(if_index == AVAHI_IF_UNSPEC){

620

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

621

" without a network interface\n");

622

retval = -1;

623

goto mandos_end;

624

}

625

/* Set the network interface number as scope */

626

to.in6.sin6_scope_id = (uint32_t)if_index;

627

}

628

} else {

629

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

564

630

-Wconversion and

565

631

-Wunreachable-code */

632

}

566

633

567

to.in6.sin6_scope_id = (uint32_t)if_index;

634

if(quit_now){

635

retval = -1;

636

goto mandos_end;

637

}

568

638

569

639

if(debug){

570

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

571

port);

572

char addrstr[INET6_ADDRSTRLEN] = "";

573

if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,

574

sizeof(addrstr)) == NULL){

640

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

641

char interface[IF_NAMESIZE];

642

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

643

perror("if_indextoname");

644

} else {

645

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

646

ip, interface, port);

647

}

648

} else {

649

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

650

port);

651

}

652

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

653

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

654

const char *pcret;

655

if(af == AF_INET6){

656

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

657

sizeof(addrstr));

658

} else {

659

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

660

sizeof(addrstr));

661

}

662

if(pcret == NULL){

575

663

perror("inet_ntop");

576

664

} else {

577

665

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

580

668

}

581

669

}

582

670

583

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

671

if(quit_now){

672

retval = -1;

673

goto mandos_end;

674

}

675

676

if(af == AF_INET6){

677

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

678

} else {

679

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

680

}

584

681

if(ret < 0){

585

682

perror("connect");

586

return -1;

683

retval = -1;

684

goto mandos_end;

685

}

686

687

if(quit_now){

688

retval = -1;

689

goto mandos_end;

587

690

}

588

691

589

692

const char *out = mandos_protocol_version;

608

711

break;

609

712

}

610

713

}

714

715

if(quit_now){

716

retval = -1;

717

goto mandos_end;

718

}

611

719

}

612

720

613

721

if(debug){

614

722

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

615

723

}

616

724

725

if(quit_now){

726

retval = -1;

727

goto mandos_end;

728

}

729

617

730

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

618

731

619

do{

732

if(quit_now){

733

retval = -1;

734

goto mandos_end;

735

}

736

737

do {

620

738

ret = gnutls_handshake(session);

739

if(quit_now){

740

retval = -1;

741

goto mandos_end;

742

}

621

743

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

622

744

623

745

if(ret != GNUTLS_E_SUCCESS){

632

754

/* Read OpenPGP packet that contains the wanted password */

633

755

634

756

if(debug){

635

fprintf(stderr, "Retrieving pgp encrypted password from %s\n",

757

fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",

636

758

ip);

637

759

}

638

760

639

761

while(true){

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

762

763

if(quit_now){

764

retval = -1;

765

goto mandos_end;

766

}

767

768

buffer_capacity = incbuffer(&buffer, buffer_length,

641

769

buffer_capacity);

642

770

if(buffer_capacity == 0){

643

perror("adjustbuffer");

771

perror("incbuffer");

772

retval = -1;

773

goto mandos_end;

774

}

775

776

if(quit_now){

644

777

retval = -1;

645

778

goto mandos_end;

646

779

}

656

789

case GNUTLS_E_AGAIN:

657

790

break;

658

791

case GNUTLS_E_REHANDSHAKE:

659

do{

792

do {

660

793

ret = gnutls_handshake(session);

794

795

if(quit_now){

796

retval = -1;

797

goto mandos_end;

798

}

661

799

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

662

800

if(ret < 0){

663

801

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

682

820

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

683

821

}

684

822

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

if(quit_now){

824

retval = -1;

825

goto mandos_end;

826

}

827

828

do {

829

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

830

if(quit_now){

831

retval = -1;

832

goto mandos_end;

833

}

834

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

686

835

687

836

if(buffer_length > 0){

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

837

ssize_t decrypted_buffer_size;

838

decrypted_buffer_size = pgp_packet_decrypt(buffer,

689

839

buffer_length,

690

840

&decrypted_buffer);

691

841

if(decrypted_buffer_size >= 0){

842

692

843

written = 0;

693

844

while(written < (size_t) decrypted_buffer_size){

845

if(quit_now){

846

retval = -1;

847

goto mandos_end;

848

}

849

694

850

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

695

851

(size_t)decrypted_buffer_size - written,

696

852

stdout);

716

872

717

873

mandos_end:

718

874

free(buffer);

719

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

875

if(tcp_sd >= 0){

876

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

877

}

720

878

if(ret == -1){

721

879

perror("close");

722

880

}

723

881

gnutls_deinit(session);

882

if(quit_now){

883

retval = -1;

884

}

724

885

return retval;

725

886

}

726

887

727

888

static void resolve_callback(AvahiSServiceResolver *r,

728

889

AvahiIfIndex interface,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

890

AvahiProtocol proto,

730

891

AvahiResolverEvent event,

731

892

const char *name,

732

893

const char *type,

737

898

AVAHI_GCC_UNUSED AvahiStringList *txt,

738

899

AVAHI_GCC_UNUSED AvahiLookupResultFlags

739

900

flags,

740

void* userdata){

741

mandos_context *mc = userdata;

901

AVAHI_GCC_UNUSED void* userdata){

742

902

assert(r);

743

903

744

904

/* Called whenever a service has been resolved successfully or

745

905

timed out */

746

906

907

if(quit_now){

908

return;

909

}

910

747

911

switch(event){

748

912

default:

749

913

case AVAHI_RESOLVER_FAILURE:

750

914

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

751

915

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

752

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

916

avahi_strerror(avahi_server_errno(mc.server)));

753

917

break;

754

918

755

919

case AVAHI_RESOLVER_FOUND:

761

925

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

762

926

ip, (intmax_t)interface, port);

763

927

}

764

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

928

int ret = start_mandos_communication(ip, port, interface,

929

avahi_proto_to_af(proto));

765

930

if(ret == 0){

766

avahi_simple_poll_quit(mc->simple_poll);

931

avahi_simple_poll_quit(mc.simple_poll);

767

932

}

768

933

}

769

934

}

779

944

const char *domain,

780

945

AVAHI_GCC_UNUSED AvahiLookupResultFlags

781

946

flags,

782

void* userdata){

783

mandos_context *mc = userdata;

947

AVAHI_GCC_UNUSED void* userdata){

784

948

assert(b);

785

949

786

950

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

787

951

is removed from the LAN */

788

952

953

if(quit_now){

954

return;

955

}

956

789

957

switch(event){

790

958

default:

791

959

case AVAHI_BROWSER_FAILURE:

792

960

793

961

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

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

962

avahi_strerror(avahi_server_errno(mc.server)));

963

avahi_simple_poll_quit(mc.simple_poll);

796

964

return;

797

965

798

966

case AVAHI_BROWSER_NEW:

801

969

the callback function is called the Avahi server will free the

802

970

resolver for us. */

803

971

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

972

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

973

name, type, domain, protocol, 0,

974

resolve_callback, NULL) == NULL)

808

975

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

809

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

976

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

810

977

break;

811

978

812

979

case AVAHI_BROWSER_REMOVE:

821

988

}

822

989

}

823

990

991

/* stop main loop after sigterm has been called */

992

static void handle_sigterm(int sig){

993

if(quit_now){

994

return;

995

}

996

quit_now = 1;

997

signal_received = sig;

998

int old_errno = errno;

999

if(mc.simple_poll != NULL){

1000

avahi_simple_poll_quit(mc.simple_poll);

1001

}

1002

errno = old_errno;

1003

}

1004

824

1005

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

825

1006

AvahiSServiceBrowser *sb = NULL;

826

1007

int error;

827

1008

int ret;

828

1009

intmax_t tmpmax;

829

int numchars;

1010

char *tmp;

830

1011

int exitcode = EXIT_SUCCESS;

831

1012

const char *interface = "eth0";

832

1013

struct ifreq network;

833

int sd;

1014

int sd = -1;

1015

bool take_down_interface = false;

834

1016

uid_t uid;

835

1017

gid_t gid;

836

1018

char *connect_to = NULL;

840

1022

const char *seckey = PATHDIR "/" SECKEY;

841

1023

const char *pubkey = PATHDIR "/" PUBKEY;

842

1024

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

846

1025

bool gnutls_initialized = false;

847

1026

bool gpgme_initialized = false;

848

double delay = 2.5;

1027

float delay = 2.5f;

1028

1029

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1030

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1031

1032

uid = getuid();

1033

gid = getgid();

1034

1035

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

1036

errno = 0;

1037

ret = setgid(gid);

1038

if(ret == -1){

1039

perror("setgid");

1040

}

1041

1042

/* Lower user privileges (temporarily) */

1043

errno = 0;

1044

ret = seteuid(uid);

1045

if(ret == -1){

1046

perror("seteuid");

1047

}

1048

1049

if(quit_now){

1050

goto end;

1051

}

849

1052

850

1053

{

851

1054

struct argp_option options[] = {

857

1060

.group = 1 },

858

1061

{ .name = "interface", .key = 'i',

859

1062

.arg = "NAME",

860

.doc = "Interface that will be used to search for Mandos"

861

" servers",

1063

.doc = "Network interface that will be used to search for"

1064

" Mandos servers",

862

1065

.group = 1 },

863

1066

{ .name = "seckey", .key = 's',

864

1067

.arg = "FILE",

903

1106

pubkey = arg;

904

1107

break;

905

1108

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

906

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

907

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

908

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

1109

errno = 0;

1110

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

1111

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

1112

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

909

1113

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

910

1114

exit(EXIT_FAILURE);

911

1115

}

915

1119

mc.priority = arg;

916

1120

break;

917

1121

case 131: /* --delay */

918

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

919

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

1122

errno = 0;

1123

delay = strtof(arg, &tmp);

1124

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

920

1125

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

921

1126

exit(EXIT_FAILURE);

922

1127

}

943

1148

}

944

1149

}

945

1150

1151

if(not debug){

1152

avahi_set_log_function(empty_log);

1153

}

1154

1155

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

1156

from the signal handler */

1157

/* Initialize the pseudo-RNG for Avahi */

1158

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

1159

mc.simple_poll = avahi_simple_poll_new();

1160

if(mc.simple_poll == NULL){

1161

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

1162

exitcode = EXIT_FAILURE;

1163

goto end;

1164

}

1165

1166

sigemptyset(&sigterm_action.sa_mask);

1167

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

1168

if(ret == -1){

1169

perror("sigaddset");

1170

exitcode = EXIT_FAILURE;

1171

goto end;

1172

}

1173

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

1174

if(ret == -1){

1175

perror("sigaddset");

1176

exitcode = EXIT_FAILURE;

1177

goto end;

1178

}

1179

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

1180

if(ret == -1){

1181

perror("sigaddset");

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

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

1186

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

1187

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

1188

*/

1189

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

1190

if(ret == -1){

1191

perror("sigaction");

1192

return EXIT_FAILURE;

1193

}

1194

if(old_sigterm_action.sa_handler != SIG_IGN){

1195

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

1196

if(ret == -1){

1197

perror("sigaction");

1198

exitcode = EXIT_FAILURE;

1199

goto end;

1200

}

1201

}

1202

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

1203

if(ret == -1){

1204

perror("sigaction");

1205

return EXIT_FAILURE;

1206

}

1207

if(old_sigterm_action.sa_handler != SIG_IGN){

1208

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

1209

if(ret == -1){

1210

perror("sigaction");

1211

exitcode = EXIT_FAILURE;

1212

goto end;

1213

}

1214

}

1215

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

1216

if(ret == -1){

1217

perror("sigaction");

1218

return EXIT_FAILURE;

1219

}

1220

if(old_sigterm_action.sa_handler != SIG_IGN){

1221

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

1222

if(ret == -1){

1223

perror("sigaction");

1224

exitcode = EXIT_FAILURE;

1225

goto end;

1226

}

1227

}

1228

946

1229

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

947

{

1230

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

1231

if_index = (AvahiIfIndex) if_nametoindex(interface);

1232

if(if_index == 0){

1233

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

1234

exitcode = EXIT_FAILURE;

1235

goto end;

1236

}

1237

1238

if(quit_now){

1239

goto end;

1240

}

1241

1242

/* Re-raise priviliges */

1243

errno = 0;

1244

ret = seteuid(0);

1245

if(ret == -1){

1246

perror("seteuid");

1247

}

1248

948

1249

#ifdef __linux__

949

1250

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

950

1251

messages to mess up the prompt */

951

1252

ret = klogctl(8, NULL, 5);

1253

bool restore_loglevel = true;

952

1254

if(ret == -1){

1255

restore_loglevel = false;

953

1256

perror("klogctl");

954

1257

}

955

#endif

1258

#endif /* __linux__ */

956

1259

957

1260

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

958

1261

if(sd < 0){

959

1262

perror("socket");

960

1263

exitcode = EXIT_FAILURE;

961

1264

#ifdef __linux__

962

ret = klogctl(7, NULL, 0);

1265

if(restore_loglevel){

1266

ret = klogctl(7, NULL, 0);

1267

if(ret == -1){

1268

perror("klogctl");

1269

}

1270

}

1271

#endif /* __linux__ */

1272

/* Lower privileges */

1273

errno = 0;

1274

ret = seteuid(uid);

963

1275

if(ret == -1){

964

perror("klogctl");

1276

perror("seteuid");

965

1277

}

966

#endif

967

1278

goto end;

968

1279

}

969

1280

strcpy(network.ifr_name, interface);

971

1282

if(ret == -1){

972

1283

perror("ioctl SIOCGIFFLAGS");

973

1284

#ifdef __linux__

974

ret = klogctl(7, NULL, 0);

1285

if(restore_loglevel){

1286

ret = klogctl(7, NULL, 0);

1287

if(ret == -1){

1288

perror("klogctl");

1289

}

1290

}

1291

#endif /* __linux__ */

1292

exitcode = EXIT_FAILURE;

1293

/* Lower privileges */

1294

errno = 0;

1295

ret = seteuid(uid);

975

1296

if(ret == -1){

976

perror("klogctl");

1297

perror("seteuid");

977

1298

}

978

#endif

979

exitcode = EXIT_FAILURE;

980

1299

goto end;

981

1300

}

982

1301

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

983

1302

network.ifr_flags |= IFF_UP;

1303

take_down_interface = true;

984

1304

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

985

1305

if(ret == -1){

1306

take_down_interface = false;

986

1307

perror("ioctl SIOCSIFFLAGS");

987

1308

exitcode = EXIT_FAILURE;

988

1309

#ifdef __linux__

989

ret = klogctl(7, NULL, 0);

1310

if(restore_loglevel){

1311

ret = klogctl(7, NULL, 0);

1312

if(ret == -1){

1313

perror("klogctl");

1314

}

1315

}

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

990

1320

if(ret == -1){

991

perror("klogctl");

1321

perror("seteuid");

992

1322

}

993

#endif

994

1323

goto end;

995

1324

}

996

1325

}

1008

1337

perror("nanosleep");

1009

1338

}

1010

1339

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1340

if(not take_down_interface){

1341

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

1342

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

1343

if(ret == -1){

1344

perror("close");

1345

}

1014

1346

}

1015

1347

#ifdef __linux__

1016

/* Restores kernel loglevel to default */

1017

ret = klogctl(7, NULL, 0);

1018

if(ret == -1){

1019

perror("klogctl");

1020

}

1021

#endif

1022

}

1023

1024

uid = getuid();

1025

gid = getgid();

1026

1027

setgid(gid);

1028

if(ret == -1){

1029

perror("setgid");

1030

}

1031

1032

ret = setuid(uid);

1033

if(ret == -1){

1034

perror("setuid");

1035

}

1036

1037

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

1348

if(restore_loglevel){

1349

/* Restores kernel loglevel to default */

1350

ret = klogctl(7, NULL, 0);

1351

if(ret == -1){

1352

perror("klogctl");

1353

}

1354

}

1355

#endif /* __linux__ */

1356

/* Lower privileges */

1357

errno = 0;

1358

if(take_down_interface){

1359

/* Lower privileges */

1360

ret = seteuid(uid);

1361

if(ret == -1){

1362

perror("seteuid");

1363

}

1364

} else {

1365

/* Lower privileges permanently */

1366

ret = setuid(uid);

1367

if(ret == -1){

1368

perror("setuid");

1369

}

1370

}

1371

}

1372

1373

if(quit_now){

1374

goto end;

1375

}

1376

1377

ret = init_gnutls_global(pubkey, seckey);

1038

1378

if(ret == -1){

1039

1379

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

1040

1380

exitcode = EXIT_FAILURE;

1043

1383

gnutls_initialized = true;

1044

1384

}

1045

1385

1386

if(quit_now){

1387

goto end;

1388

}

1389

1390

tempdir_created = true;

1046

1391

if(mkdtemp(tempdir) == NULL){

1392

tempdir_created = false;

1047

1393

perror("mkdtemp");

1048

1394

goto end;

1049

1395

}

1050

tempdir_created = true;

1051

1052

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

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1401

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

1053

1402

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

1054

1403

exitcode = EXIT_FAILURE;

1055

1404

goto end;

1057

1406

gpgme_initialized = true;

1058

1407

}

1059

1408

1060

if_index = (AvahiIfIndex) if_nametoindex(interface);

1061

if(if_index == 0){

1062

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

1063

exitcode = EXIT_FAILURE;

1409

if(quit_now){

1064

1410

goto end;

1065

1411

}

1066

1412

1073

1419

exitcode = EXIT_FAILURE;

1074

1420

goto end;

1075

1421

}

1422

1423

if(quit_now){

1424

goto end;

1425

}

1426

1076

1427

uint16_t port;

1077

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

1078

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

1079

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

1428

errno = 0;

1429

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

1430

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

1431

or tmpmax != (uint16_t)tmpmax){

1080

1432

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

1081

1433

exitcode = EXIT_FAILURE;

1082

1434

goto end;

1083

1435

}

1436

1437

if(quit_now){

1438

goto end;

1439

}

1440

1084

1441

port = (uint16_t)tmpmax;

1085

1442

*address = '\0';

1086

1443

address = connect_to;

1087

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

1444

/* Colon in address indicates IPv6 */

1445

int af;

1446

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

1447

af = AF_INET6;

1448

} else {

1449

af = AF_INET;

1450

}

1451

1452

if(quit_now){

1453

goto end;

1454

}

1455

1456

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

1088

1457

if(ret < 0){

1089

1458

exitcode = EXIT_FAILURE;

1090

1459

} else {

1093

1462

goto end;

1094

1463

}

1095

1464

1096

if(not debug){

1097

avahi_set_log_function(empty_log);

1098

}

1099

1100

/* Initialize the pseudo-RNG for Avahi */

1101

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

1102

1103

/* Allocate main Avahi loop object */

1104

mc.simple_poll = avahi_simple_poll_new();

1105

if(mc.simple_poll == NULL){

1106

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

1107

exitcode = EXIT_FAILURE;

1465

if(quit_now){

1108

1466

goto end;

1109

1467

}

1110

1468

1134

1492

goto end;

1135

1493

}

1136

1494

1495

if(quit_now){

1496

goto end;

1497

}

1498

1137

1499

/* Create the Avahi service browser */

1138

1500

sb = avahi_s_service_browser_new(mc.server, if_index,

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1501

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1502

NULL, 0, browse_callback, NULL);

1141

1503

if(sb == NULL){

1142

1504

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

1143

1505

avahi_strerror(avahi_server_errno(mc.server)));

1145

1507

goto end;

1146

1508

}

1147

1509

1510

if(quit_now){

1511

goto end;

1512

}

1513

1148

1514

/* Run the main loop */

1149

1515

1150

1516

if(debug){

1179

1545

gpgme_release(mc.ctx);

1180

1546

}

1181

1547

1548

/* Take down the network interface */

1549

if(take_down_interface){

1550

/* Re-raise priviliges */

1551

errno = 0;

1552

ret = seteuid(0);

1553

if(ret == -1){

1554

perror("seteuid");

1555

}

1556

if(geteuid() == 0){

1557

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

1558

if(ret == -1){

1559

perror("ioctl SIOCGIFFLAGS");

1560

} else if(network.ifr_flags & IFF_UP) {

1561

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

1562

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

1563

if(ret == -1){

1564

perror("ioctl SIOCSIFFLAGS");

1565

}

1566

}

1567

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

1568

if(ret == -1){

1569

perror("close");

1570

}

1571

/* Lower privileges permanently */

1572

errno = 0;

1573

ret = setuid(uid);

1574

if(ret == -1){

1575

perror("setuid");

1576

}

1577

}

1578

}

1579

1182

1580

/* Removes the temp directory used by GPGME */

1183

1581

if(tempdir_created){

1184

1582

DIR *d;

1223

1621

}

1224

1622

}

1225

1623

1624

if(quit_now){

1625

sigemptyset(&old_sigterm_action.sa_mask);

1626

old_sigterm_action.sa_handler = SIG_DFL;

1627

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

1628

if(ret == -1){

1629

perror("sigaction");

1630

}

1631

raise(signal_received);

1632

}

1633

1226

1634

return exitcode;

1227

1635

}