/mandos/trunk : revision 365

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 */

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45

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

43

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 */

46

49

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

47

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,

51

SOCK_STREAM, INET6_ADDRSTRLEN,

52

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

53

DIR */

54

SOCK_STREAM, uid_t, gid_t, open(),

55

opendir(), DIR */

54

56

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

55

57

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

56

struct in6_addr, inet_pton(),

57

connect() */

58

inet_pton(), connect() */

58

59

#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,

63

strtoimax() */

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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,

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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

75

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

88

#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"

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

144

132

145

/*

133

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

134

* "buffer_capacity" is how much is currently allocated,

146

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

147

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

135

148

* "buffer_length" is how much is already used.

136

149

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

150

size_t incbuffer(char **buffer, size_t buffer_length,

138

151

size_t buffer_capacity){

139

152

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

153

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

149

162

/*

150

163

* Initialize GPGME.

151

164

*/

152

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

165

static bool init_gpgme(const char *seckey,

153

166

const char *pubkey, const char *tempdir){

154

int ret;

155

167

gpgme_error_t rc;

156

168

gpgme_engine_info_t engine_info;

157

169

160

172

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

161

173

*/

162

174

bool import_key(const char *filename){

175

int ret;

163

176

int fd;

164

177

gpgme_data_t pgp_data;

165

178

176

189

return false;

177

190

}

178

191

179

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

192

rc = gpgme_op_import(mc.ctx, pgp_data);

180

193

if(rc != GPG_ERR_NO_ERROR){

181

194

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

182

195

gpgme_strsource(rc), gpgme_strerror(rc));

192

205

}

193

206

194

207

if(debug){

195

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

208

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

196

209

}

197

210

198

211

/* Init GPGME */

225

238

}

226

239

227

240

/* Create new GPGME "context" */

228

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

241

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

229

242

if(rc != GPG_ERR_NO_ERROR){

230

243

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

231

244

gpgme_strsource(rc), gpgme_strerror(rc));

236

249

return false;

237

250

}

238

251

239

return true;

252

return true;

240

253

}

241

254

242

255

/*

243

256

* Decrypt OpenPGP data.

244

257

* Returns -1 on error

245

258

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

259

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

260

size_t crypto_size,

249

261

char **plaintext){

250

262

gpgme_data_t dh_crypto, dh_plain;

277

289

278

290

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

279

291

data buffer */

280

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

292

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

281

293

if(rc != GPG_ERR_NO_ERROR){

282

294

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

283

295

gpgme_strsource(rc), gpgme_strerror(rc));

284

296

plaintext_length = -1;

285

297

if(debug){

286

298

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

299

result = gpgme_op_decrypt_result(mc.ctx);

288

300

if(result == NULL){

289

301

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

290

302

} else {

297

309

}

298

310

gpgme_recipient_t recipient;

299

311

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

}

312

while(recipient != NULL){

313

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

314

gpgme_pubkey_algo_name(recipient->pubkey_algo));

315

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

316

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

317

recipient->status == GPG_ERR_NO_SECKEY

318

? "No" : "Yes");

319

recipient = recipient->next;

310

320

}

311

321

}

312

322

}

326

336

327

337

*plaintext = NULL;

328

338

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

339

plaintext_capacity = incbuffer(plaintext,

330

340

(size_t)plaintext_length,

331

341

plaintext_capacity);

332

342

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

343

perror("incbuffer");

334

344

plaintext_length = -1;

335

345

goto decrypt_end;

336

346

}

382

392

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

383

393

}

384

394

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

395

static int init_gnutls_global(const char *pubkeyfilename,

387

396

const char *seckeyfilename){

388

397

int ret;

389

398

407

416

}

408

417

409

418

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

419

gnutls_certificate_allocate_credentials(&mc.cred);

411

420

if(ret != GNUTLS_E_SUCCESS){

412

421

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

413

* from

414

* -Wunreachable-code

415

*/

422

from

423

-Wunreachable-code

424

*/

416

425

safer_gnutls_strerror(ret));

417

426

gnutls_global_deinit();

418

427

return -1;

425

434

}

426

435

427

436

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

437

(mc.cred, pubkeyfilename, seckeyfilename,

429

438

GNUTLS_OPENPGP_FMT_BASE64);

430

439

if(ret != GNUTLS_E_SUCCESS){

431

440

fprintf(stderr,

437

446

}

438

447

439

448

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

449

ret = gnutls_dh_params_init(&mc.dh_params);

441

450

if(ret != GNUTLS_E_SUCCESS){

442

451

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

443

452

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

444

453

goto globalfail;

445

454

}

446

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

455

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

447

456

if(ret != GNUTLS_E_SUCCESS){

448

457

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

449

458

safer_gnutls_strerror(ret));

450

459

goto globalfail;

451

460

}

452

461

453

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

462

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

463

455

464

return 0;

456

465

457

466

globalfail:

458

467

459

gnutls_certificate_free_credentials(mc->cred);

468

gnutls_certificate_free_credentials(mc.cred);

460

469

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

470

gnutls_dh_params_deinit(mc.dh_params);

462

471

return -1;

463

472

}

464

473

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

474

static int init_gnutls_session(gnutls_session_t *session){

467

475

int ret;

468

476

/* GnuTLS session creation */

469

477

ret = gnutls_init(session, GNUTLS_SERVER);

474

482

475

483

{

476

484

const char *err;

477

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

485

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

478

486

if(ret != GNUTLS_E_SUCCESS){

479

487

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

480

488

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

485

493

}

486

494

487

495

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

496

mc.cred);

489

497

if(ret != GNUTLS_E_SUCCESS){

490

498

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

491

499

safer_gnutls_strerror(ret));

497

505

gnutls_certificate_server_set_request(*session,

498

506

GNUTLS_CERT_IGNORE);

499

507

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

508

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

509

502

510

return 0;

503

511

}

506

514

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

507

515

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

508

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

509

520

/* Called when a Mandos server is found */

510

521

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

511

522

AvahiIfIndex if_index,

512

mandos_context *mc){

513

int ret, tcp_sd;

523

int af){

524

int ret, tcp_sd = -1;

514

525

ssize_t sret;

515

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

526

union {

527

struct sockaddr_in in;

528

struct sockaddr_in6 in6;

529

} to;

516

530

char *buffer = NULL;

517

531

char *decrypted_buffer;

518

532

size_t buffer_length = 0;

519

533

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

521

534

size_t written;

522

535

int retval = 0;

523

char interface[IF_NAMESIZE];

524

536

gnutls_session_t session;

525

526

ret = init_gnutls_session(mc, &session);

537

int pf; /* Protocol family */

538

539

if(quit_now){

540

return -1;

541

}

542

543

switch(af){

544

case AF_INET6:

545

pf = PF_INET6;

546

break;

547

case AF_INET:

548

pf = PF_INET;

549

break;

550

default:

551

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

552

return -1;

553

}

554

555

ret = init_gnutls_session(&session);

527

556

if(ret != 0){

528

557

return -1;

529

558

}

530

559

531

560

if(debug){

532

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

561

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

533

562

"\n", ip, port);

534

563

}

535

564

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

537

566

if(tcp_sd < 0){

538

567

perror("socket");

539

return -1;

568

retval = -1;

569

goto mandos_end;

540

570

}

541

571

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);

572

if(quit_now){

573

goto mandos_end;

548

574

}

549

575

550

576

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);

577

if(af == AF_INET6){

578

to.in6.sin6_family = (sa_family_t)af;

579

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

580

} else { /* IPv4 */

581

to.in.sin_family = (sa_family_t)af;

582

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

583

}

555

584

if(ret < 0 ){

556

585

perror("inet_pton");

557

return -1;

586

retval = -1;

587

goto mandos_end;

558

588

}

559

589

if(ret == 0){

560

590

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

561

return -1;

591

retval = -1;

592

goto mandos_end;

562

593

}

563

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

594

if(af == AF_INET6){

595

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

596

-Wconversion and

597

-Wunreachable-code */

598

599

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

600

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

601

-Wunreachable-code*/

602

if(if_index == AVAHI_IF_UNSPEC){

603

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

604

" without a network interface\n");

605

retval = -1;

606

goto mandos_end;

607

}

608

/* Set the network interface number as scope */

609

to.in6.sin6_scope_id = (uint32_t)if_index;

610

}

611

} else {

612

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

564

613

-Wconversion and

565

614

-Wunreachable-code */

615

}

566

616

567

to.in6.sin6_scope_id = (uint32_t)if_index;

617

if(quit_now){

618

goto mandos_end;

619

}

568

620

569

621

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){

622

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

623

char interface[IF_NAMESIZE];

624

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

625

perror("if_indextoname");

626

} else {

627

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

628

ip, interface, port);

629

}

630

} else {

631

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

632

port);

633

}

634

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

635

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

636

const char *pcret;

637

if(af == AF_INET6){

638

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

639

sizeof(addrstr));

640

} else {

641

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

642

sizeof(addrstr));

643

}

644

if(pcret == NULL){

575

645

perror("inet_ntop");

576

646

} else {

577

647

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

580

650

}

581

651

}

582

652

583

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

653

if(quit_now){

654

goto mandos_end;

655

}

656

657

if(af == AF_INET6){

658

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

659

} else {

660

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

661

}

584

662

if(ret < 0){

585

663

perror("connect");

586

return -1;

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

587

670

}

588

671

589

672

const char *out = mandos_protocol_version;

608

691

break;

609

692

}

610

693

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

611

698

}

612

699

613

700

if(debug){

614

701

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

615

702

}

616

703

704

if(quit_now){

705

goto mandos_end;

706

}

707

617

708

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

618

709

619

do{

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

620

715

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

621

719

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

622

720

623

721

if(ret != GNUTLS_E_SUCCESS){

632

730

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

633

731

634

732

if(debug){

635

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

733

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

636

734

ip);

637

735

}

638

736

639

737

while(true){

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

743

buffer_capacity = incbuffer(&buffer, buffer_length,

641

744

buffer_capacity);

642

745

if(buffer_capacity == 0){

643

perror("adjustbuffer");

746

perror("incbuffer");

644

747

retval = -1;

645

748

goto mandos_end;

646

749

}

647

750

751

if(quit_now){

752

goto mandos_end;

753

}

754

648

755

sret = gnutls_record_recv(session, buffer+buffer_length,

649

756

BUFFER_SIZE);

650

757

if(sret == 0){

656

763

case GNUTLS_E_AGAIN:

657

764

break;

658

765

case GNUTLS_E_REHANDSHAKE:

659

do{

766

do {

660

767

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

661

772

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

662

773

if(ret < 0){

663

774

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

682

793

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

683

794

}

684

795

796

if(quit_now){

797

goto mandos_end;

798

}

799

685

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

686

801

802

if(quit_now){

803

goto mandos_end;

804

}

805

687

806

if(buffer_length > 0){

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

807

ssize_t decrypted_buffer_size;

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

689

809

buffer_length,

690

810

&decrypted_buffer);

691

811

if(decrypted_buffer_size >= 0){

812

692

813

written = 0;

693

814

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

694

819

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

695

820

(size_t)decrypted_buffer_size - written,

696

821

stdout);

716

841

717

842

mandos_end:

718

843

free(buffer);

719

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

844

if(tcp_sd >= 0){

845

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

846

}

720

847

if(ret == -1){

721

848

perror("close");

722

849

}

723

850

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

724

854

return retval;

725

855

}

726

856

727

857

static void resolve_callback(AvahiSServiceResolver *r,

728

858

AvahiIfIndex interface,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

859

AvahiProtocol proto,

730

860

AvahiResolverEvent event,

731

861

const char *name,

732

862

const char *type,

737

867

AVAHI_GCC_UNUSED AvahiStringList *txt,

738

868

AVAHI_GCC_UNUSED AvahiLookupResultFlags

739

869

flags,

740

void* userdata){

741

mandos_context *mc = userdata;

870

AVAHI_GCC_UNUSED void* userdata){

742

871

assert(r);

743

872

744

873

/* Called whenever a service has been resolved successfully or

745

874

timed out */

746

875

876

if(quit_now){

877

return;

878

}

879

747

880

switch(event){

748

881

default:

749

882

case AVAHI_RESOLVER_FAILURE:

750

883

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

751

884

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

752

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

885

avahi_strerror(avahi_server_errno(mc.server)));

753

886

break;

754

887

755

888

case AVAHI_RESOLVER_FOUND:

761

894

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

762

895

ip, (intmax_t)interface, port);

763

896

}

764

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

897

int ret = start_mandos_communication(ip, port, interface,

898

avahi_proto_to_af(proto));

765

899

if(ret == 0){

766

avahi_simple_poll_quit(mc->simple_poll);

900

avahi_simple_poll_quit(mc.simple_poll);

767

901

}

768

902

}

769

903

}

779

913

const char *domain,

780

914

AVAHI_GCC_UNUSED AvahiLookupResultFlags

781

915

flags,

782

void* userdata){

783

mandos_context *mc = userdata;

916

AVAHI_GCC_UNUSED void* userdata){

784

917

assert(b);

785

918

786

919

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

787

920

is removed from the LAN */

788

921

922

if(quit_now){

923

return;

924

}

925

789

926

switch(event){

790

927

default:

791

928

case AVAHI_BROWSER_FAILURE:

792

929

793

930

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

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

931

avahi_strerror(avahi_server_errno(mc.server)));

932

avahi_simple_poll_quit(mc.simple_poll);

796

933

return;

797

934

798

935

case AVAHI_BROWSER_NEW:

801

938

the callback function is called the Avahi server will free the

802

939

resolver for us. */

803

940

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

941

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

942

name, type, domain, protocol, 0,

943

resolve_callback, NULL) == NULL)

808

944

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

809

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

945

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

810

946

break;

811

947

812

948

case AVAHI_BROWSER_REMOVE:

821

957

}

822

958

}

823

959

960

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

961

static void handle_sigterm(int sig){

962

if(quit_now){

963

return;

964

}

965

quit_now = 1;

966

signal_received = sig;

967

int old_errno = errno;

968

if(mc.simple_poll != NULL){

969

avahi_simple_poll_quit(mc.simple_poll);

970

}

971

errno = old_errno;

972

}

973

824

974

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

825

975

AvahiSServiceBrowser *sb = NULL;

826

976

int error;

827

977

int ret;

828

978

intmax_t tmpmax;

829

int numchars;

979

char *tmp;

830

980

int exitcode = EXIT_SUCCESS;

831

981

const char *interface = "eth0";

832

982

struct ifreq network;

833

int sd;

983

int sd = -1;

984

bool take_down_interface = false;

834

985

uid_t uid;

835

986

gid_t gid;

836

987

char *connect_to = NULL;

840

991

const char *seckey = PATHDIR "/" SECKEY;

841

992

const char *pubkey = PATHDIR "/" PUBKEY;

842

993

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

846

994

bool gnutls_initialized = false;

847

995

bool gpgme_initialized = false;

848

double delay = 2.5;

996

float delay = 2.5f;

997

998

struct sigaction old_sigterm_action;

999

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

849

1000

850

1001

{

851

1002

struct argp_option options[] = {

857

1008

.group = 1 },

858

1009

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

859

1010

.arg = "NAME",

860

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

861

" servers",

1011

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

1012

" Mandos servers",

862

1013

.group = 1 },

863

1014

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

864

1015

.arg = "FILE",

903

1054

pubkey = arg;

904

1055

break;

905

1056

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'){

1057

errno = 0;

1058

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

1059

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

1060

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

909

1061

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

910

1062

exit(EXIT_FAILURE);

911

1063

}

915

1067

mc.priority = arg;

916

1068

break;

917

1069

case 131: /* --delay */

918

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

919

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

1070

errno = 0;

1071

delay = strtof(arg, &tmp);

1072

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

920

1073

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

921

1074

exit(EXIT_FAILURE);

922

1075

}

943

1096

}

944

1097

}

945

1098

1099

if(not debug){

1100

avahi_set_log_function(empty_log);

1101

}

1102

1103

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

1104

from the signal handler */

1105

/* Initialize the pseudo-RNG for Avahi */

1106

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

1107

mc.simple_poll = avahi_simple_poll_new();

1108

if(mc.simple_poll == NULL){

1109

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

1110

exitcode = EXIT_FAILURE;

1111

goto end;

1112

}

1113

1114

sigemptyset(&sigterm_action.sa_mask);

1115

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

1116

if(ret == -1){

1117

perror("sigaddset");

1118

exitcode = EXIT_FAILURE;

1119

goto end;

1120

}

1121

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

1122

if(ret == -1){

1123

perror("sigaddset");

1124

exitcode = EXIT_FAILURE;

1125

goto end;

1126

}

1127

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

1128

if(ret == -1){

1129

perror("sigaddset");

1130

exitcode = EXIT_FAILURE;

1131

goto end;

1132

}

1133

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

1134

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

1135

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

1136

*/

1137

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

1138

if(ret == -1){

1139

perror("sigaction");

1140

return EXIT_FAILURE;

1141

}

1142

if(old_sigterm_action.sa_handler != SIG_IGN){

1143

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

1144

if(ret == -1){

1145

perror("sigaction");

1146

exitcode = EXIT_FAILURE;

1147

goto end;

1148

}

1149

}

1150

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

1151

if(ret == -1){

1152

perror("sigaction");

1153

return EXIT_FAILURE;

1154

}

1155

if(old_sigterm_action.sa_handler != SIG_IGN){

1156

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

1157

if(ret == -1){

1158

perror("sigaction");

1159

exitcode = EXIT_FAILURE;

1160

goto end;

1161

}

1162

}

1163

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

1164

if(ret == -1){

1165

perror("sigaction");

1166

return EXIT_FAILURE;

1167

}

1168

if(old_sigterm_action.sa_handler != SIG_IGN){

1169

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

1170

if(ret == -1){

1171

perror("sigaction");

1172

exitcode = EXIT_FAILURE;

1173

goto end;

1174

}

1175

}

1176

946

1177

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

947

{

1178

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

1179

if_index = (AvahiIfIndex) if_nametoindex(interface);

1180

if(if_index == 0){

1181

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

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

1186

if(quit_now){

1187

goto end;

1188

}

1189

948

1190

#ifdef __linux__

949

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

950

1192

messages to mess up the prompt */

951

1193

ret = klogctl(8, NULL, 5);

1194

bool restore_loglevel = true;

952

1195

if(ret == -1){

1196

restore_loglevel = false;

953

1197

perror("klogctl");

954

1198

}

955

#endif

1199

#endif /* __linux__ */

956

1200

957

1201

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

958

1202

if(sd < 0){

959

1203

perror("socket");

960

1204

exitcode = EXIT_FAILURE;

961

1205

#ifdef __linux__

962

ret = klogctl(7, NULL, 0);

963

if(ret == -1){

964

perror("klogctl");

1206

if(restore_loglevel){

1207

ret = klogctl(7, NULL, 0);

1208

if(ret == -1){

1209

perror("klogctl");

1210

}

965

1211

}

966

#endif

1212

#endif /* __linux__ */

967

1213

goto end;

968

1214

}

969

1215

strcpy(network.ifr_name, interface);

971

1217

if(ret == -1){

972

1218

perror("ioctl SIOCGIFFLAGS");

973

1219

#ifdef __linux__

974

ret = klogctl(7, NULL, 0);

975

if(ret == -1){

976

perror("klogctl");

1220

if(restore_loglevel){

1221

ret = klogctl(7, NULL, 0);

1222

if(ret == -1){

1223

perror("klogctl");

1224

}

977

1225

}

978

#endif

1226

#endif /* __linux__ */

979

1227

exitcode = EXIT_FAILURE;

980

1228

goto end;

981

1229

}

982

1230

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

983

1231

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

984

1233

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

985

1234

if(ret == -1){

1235

take_down_interface = false;

986

1236

perror("ioctl SIOCSIFFLAGS");

987

1237

exitcode = EXIT_FAILURE;

988

1238

#ifdef __linux__

989

ret = klogctl(7, NULL, 0);

990

if(ret == -1){

991

perror("klogctl");

1239

if(restore_loglevel){

1240

ret = klogctl(7, NULL, 0);

1241

if(ret == -1){

1242

perror("klogctl");

1243

}

992

1244

}

993

#endif

1245

#endif /* __linux__ */

994

1246

goto end;

995

1247

}

996

1248

}

1008

1260

perror("nanosleep");

1009

1261

}

1010

1262

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1263

if(not take_down_interface){

1264

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

1265

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

1266

if(ret == -1){

1267

perror("close");

1268

}

1014

1269

}

1015

1270

#ifdef __linux__

1016

/* Restores kernel loglevel to default */

1017

ret = klogctl(7, NULL, 0);

1018

if(ret == -1){

1019

perror("klogctl");

1271

if(restore_loglevel){

1272

/* Restores kernel loglevel to default */

1273

ret = klogctl(7, NULL, 0);

1274

if(ret == -1){

1275

perror("klogctl");

1276

}

1020

1277

}

1021

#endif

1278

#endif /* __linux__ */

1279

}

1280

1281

if(quit_now){

1282

goto end;

1022

1283

}

1023

1284

1024

1285

uid = getuid();

1025

1286

gid = getgid();

1026

1287

1027

setgid(gid);

1288

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

1289

errno = 0;

1290

ret = setgid(gid);

1028

1291

if(ret == -1){

1029

1292

perror("setgid");

1030

1293

}

1031

1294

1032

ret = setuid(uid);

1033

if(ret == -1){

1034

perror("setuid");

1035

}

1036

1037

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

1295

/* Drop user privileges */

1296

errno = 0;

1297

/* Will we need privileges later? */

1298

if(take_down_interface){

1299

/* Drop user privileges temporarily */

1300

ret = seteuid(uid);

1301

if(ret == -1){

1302

perror("seteuid");

1303

}

1304

} else {

1305

/* Drop user privileges permanently */

1306

ret = setuid(uid);

1307

if(ret == -1){

1308

perror("setuid");

1309

}

1310

}

1311

1312

if(quit_now){

1313

goto end;

1314

}

1315

1316

ret = init_gnutls_global(pubkey, seckey);

1038

1317

if(ret == -1){

1039

1318

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

1040

1319

exitcode = EXIT_FAILURE;

1043

1322

gnutls_initialized = true;

1044

1323

}

1045

1324

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1046

1330

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1047

1332

perror("mkdtemp");

1048

1333

goto end;

1049

1334

}

1050

tempdir_created = true;

1051

1052

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

1335

1336

if(quit_now){

1337

goto end;

1338

}

1339

1340

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

1053

1341

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

1054

1342

exitcode = EXIT_FAILURE;

1055

1343

goto end;

1057

1345

gpgme_initialized = true;

1058

1346

}

1059

1347

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;

1348

if(quit_now){

1064

1349

goto end;

1065

1350

}

1066

1351

1073

1358

exitcode = EXIT_FAILURE;

1074

1359

goto end;

1075

1360

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1076

1366

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'){

1367

errno = 0;

1368

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

1369

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

1370

or tmpmax != (uint16_t)tmpmax){

1080

1371

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

1081

1372

exitcode = EXIT_FAILURE;

1082

1373

goto end;

1083

1374

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1084

1380

port = (uint16_t)tmpmax;

1085

1381

*address = '\0';

1086

1382

address = connect_to;

1087

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

1383

/* Colon in address indicates IPv6 */

1384

int af;

1385

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

1386

af = AF_INET6;

1387

} else {

1388

af = AF_INET;

1389

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1395

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

1088

1396

if(ret < 0){

1089

1397

exitcode = EXIT_FAILURE;

1090

1398

} else {

1093

1401

goto end;

1094

1402

}

1095

1403

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;

1404

if(quit_now){

1108

1405

goto end;

1109

1406

}

1110

1407

1134

1431

goto end;

1135

1432

}

1136

1433

1434

if(quit_now){

1435

goto end;

1436

}

1437

1137

1438

/* Create the Avahi service browser */

1138

1439

sb = avahi_s_service_browser_new(mc.server, if_index,

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1441

NULL, 0, browse_callback, NULL);

1141

1442

if(sb == NULL){

1142

1443

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

1143

1444

avahi_strerror(avahi_server_errno(mc.server)));

1145

1446

goto end;

1146

1447

}

1147

1448

1449

if(quit_now){

1450

goto end;

1451

}

1452

1148

1453

/* Run the main loop */

1149

1454

1150

1455

if(debug){

1179

1484

gpgme_release(mc.ctx);

1180

1485

}

1181

1486

1487

/* Take down the network interface */

1488

if(take_down_interface){

1489

/* Re-raise priviliges */

1490

errno = 0;

1491

ret = seteuid(0);

1492

if(ret == -1){

1493

perror("seteuid");

1494

}

1495

if(geteuid() == 0){

1496

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

1497

if(ret == -1){

1498

perror("ioctl SIOCGIFFLAGS");

1499

} else if(network.ifr_flags & IFF_UP) {

1500

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

1501

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

1502

if(ret == -1){

1503

perror("ioctl SIOCSIFFLAGS");

1504

}

1505

}

1506

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

1507

if(ret == -1){

1508

perror("close");

1509

}

1510

/* Lower privileges, permanently this time */

1511

errno = 0;

1512

ret = setuid(uid);

1513

if(ret == -1){

1514

perror("setuid");

1515

}

1516

}

1517

}

1518

1182

1519

/* Removes the temp directory used by GPGME */

1183

1520

if(tempdir_created){

1184

1521

DIR *d;

1223

1560

}

1224

1561

}

1225

1562

1563

if(quit_now){

1564

sigemptyset(&old_sigterm_action.sa_mask);

1565

old_sigterm_action.sa_handler = SIG_DFL;

1566

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

1567

if(ret == -1){

1568

perror("sigaction");

1569

}

1570

raise(signal_received);

1571

}

1572

1226

1573

return exitcode;

1227

1574

}