/mandos/trunk : revision 24.1.143

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

46

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

44

srand() */

45

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

47

srand(), strtof(), abort() */

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,

50

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() */

59

60

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

60

61

*/

61

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

62

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

63

strtoimax() */

62

64

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

63

65

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

64

66

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

65

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,

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

69

73

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

70

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

71

setgid() */

74

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

75

setgid(), pause() */

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__

79

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"

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,

135

151

* "buffer_length" is how much is already used.

136

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

175

* 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){

181

197

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

182

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);

288

303

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",

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

}

315

while(recipient != NULL){

316

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

317

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");

334

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

char *decrypted_buffer;

547

char *decrypted_buffer = NULL;

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

int retval = 0;

523

char interface[IF_NAMESIZE];

551

int retval = -1;

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

goto mandos_end;

540

585

}

541

586

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);

587

if(quit_now){

588

goto mandos_end;

548

589

}

549

590

550

591

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);

592

if(af == AF_INET6){

593

to.in6.sin6_family = (sa_family_t)af;

594

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

595

} else { /* IPv4 */

596

to.in.sin_family = (sa_family_t)af;

597

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

598

}

555

599

if(ret < 0 ){

556

600

perror("inet_pton");

557

return -1;

601

goto mandos_end;

558

602

}

559

603

if(ret == 0){

560

604

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

561

return -1;

605

goto mandos_end;

562

606

}

563

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

607

if(af == AF_INET6){

608

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

609

-Wconversion and

610

-Wunreachable-code */

611

612

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

613

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

614

-Wunreachable-code*/

615

if(if_index == AVAHI_IF_UNSPEC){

616

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

617

" without a network interface\n");

618

goto mandos_end;

619

}

620

/* Set the network interface number as scope */

621

to.in6.sin6_scope_id = (uint32_t)if_index;

622

}

623

} else {

624

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

564

625

-Wconversion and

565

626

-Wunreachable-code */

627

}

566

628

567

to.in6.sin6_scope_id = (uint32_t)if_index;

629

if(quit_now){

630

goto mandos_end;

631

}

568

632

569

633

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){

634

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

635

char interface[IF_NAMESIZE];

636

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

637

perror("if_indextoname");

638

} else {

639

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

640

ip, interface, port);

641

}

642

} else {

643

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

644

port);

645

}

646

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

647

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

648

const char *pcret;

649

if(af == AF_INET6){

650

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

651

sizeof(addrstr));

652

} else {

653

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

654

sizeof(addrstr));

655

}

656

if(pcret == NULL){

575

657

perror("inet_ntop");

576

658

} else {

577

659

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

580

662

}

581

663

}

582

664

583

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

665

if(quit_now){

666

goto mandos_end;

667

}

668

669

if(af == AF_INET6){

670

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

671

} else {

672

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

673

}

584

674

if(ret < 0){

585

675

perror("connect");

586

return -1;

676

goto mandos_end;

677

}

678

679

if(quit_now){

680

goto mandos_end;

587

681

}

588

682

589

683

const char *out = mandos_protocol_version;

594

688

out_size - written));

595

689

if(ret == -1){

596

690

perror("write");

597

retval = -1;

598

691

goto mandos_end;

599

692

}

600

693

written += (size_t)ret;

608

701

break;

609

702

}

610

703

}

704

705

if(quit_now){

706

goto mandos_end;

707

}

611

708

}

612

709

613

710

if(debug){

614

711

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

615

712

}

616

713

714

if(quit_now){

715

goto mandos_end;

716

}

717

617

718

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

618

719

619

do{

720

if(quit_now){

721

goto mandos_end;

722

}

723

724

do {

620

725

ret = gnutls_handshake(session);

726

if(quit_now){

727

goto mandos_end;

728

}

621

729

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

622

730

623

731

if(ret != GNUTLS_E_SUCCESS){

625

733

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

626

734

gnutls_perror(ret);

627

735

}

628

retval = -1;

629

736

goto mandos_end;

630

737

}

631

738

632

739

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

633

740

634

741

if(debug){

635

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

742

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

636

743

ip);

637

744

}

638

745

639

746

while(true){

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

747

748

if(quit_now){

749

goto mandos_end;

750

}

751

752

buffer_capacity = incbuffer(&buffer, buffer_length,

641

753

buffer_capacity);

642

754

if(buffer_capacity == 0){

643

perror("adjustbuffer");

644

retval = -1;

755

perror("incbuffer");

756

goto mandos_end;

757

}

758

759

if(quit_now){

645

760

goto mandos_end;

646

761

}

647

762

656

771

case GNUTLS_E_AGAIN:

657

772

break;

658

773

case GNUTLS_E_REHANDSHAKE:

659

do{

774

do {

660

775

ret = gnutls_handshake(session);

776

777

if(quit_now){

778

goto mandos_end;

779

}

661

780

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

662

781

if(ret < 0){

663

782

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

664

783

gnutls_perror(ret);

665

retval = -1;

666

784

goto mandos_end;

667

785

}

668

786

break;

669

787

default:

670

788

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

671

789

" encrypted session with Mandos server\n");

672

retval = -1;

673

790

gnutls_bye(session, GNUTLS_SHUT_RDWR);

674

791

goto mandos_end;

675

792

}

682

799

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

683

800

}

684

801

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

802

if(quit_now){

803

goto mandos_end;

804

}

805

806

do {

807

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

808

if(quit_now){

809

goto mandos_end;

810

}

811

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

686

812

687

813

if(buffer_length > 0){

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

814

ssize_t decrypted_buffer_size;

815

decrypted_buffer_size = pgp_packet_decrypt(buffer,

689

816

buffer_length,

690

817

&decrypted_buffer);

691

818

if(decrypted_buffer_size >= 0){

819

692

820

written = 0;

693

821

while(written < (size_t) decrypted_buffer_size){

822

if(quit_now){

823

goto mandos_end;

824

}

825

694

826

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

695

827

(size_t)decrypted_buffer_size - written,

696

828

stdout);

699

831

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

700

832

strerror(errno));

701

833

}

702

retval = -1;

703

break;

834

goto mandos_end;

704

835

}

705

836

written += (size_t)ret;

706

837

}

707

free(decrypted_buffer);

708

} else {

709

retval = -1;

838

retval = 0;

710

839

}

711

} else {

712

retval = -1;

713

840

}

714

841

715

842

/* Shutdown procedure */

716

843

717

844

mandos_end:

845

free(decrypted_buffer);

718

846

free(buffer);

719

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

847

if(tcp_sd >= 0){

848

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

849

}

720

850

if(ret == -1){

721

851

perror("close");

722

852

}

723

853

gnutls_deinit(session);

854

if(quit_now){

855

retval = -1;

856

}

724

857

return retval;

725

858

}

726

859

727

860

static void resolve_callback(AvahiSServiceResolver *r,

728

861

AvahiIfIndex interface,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

862

AvahiProtocol proto,

730

863

AvahiResolverEvent event,

731

864

const char *name,

732

865

const char *type,

737

870

AVAHI_GCC_UNUSED AvahiStringList *txt,

738

871

AVAHI_GCC_UNUSED AvahiLookupResultFlags

739

872

flags,

740

void* userdata){

741

mandos_context *mc = userdata;

873

AVAHI_GCC_UNUSED void* userdata){

742

874

assert(r);

743

875

744

876

/* Called whenever a service has been resolved successfully or

745

877

timed out */

746

878

879

if(quit_now){

880

return;

881

}

882

747

883

switch(event){

748

884

default:

749

885

case AVAHI_RESOLVER_FAILURE:

750

886

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

751

887

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

752

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

888

avahi_strerror(avahi_server_errno(mc.server)));

753

889

break;

754

890

755

891

case AVAHI_RESOLVER_FOUND:

761

897

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

762

898

ip, (intmax_t)interface, port);

763

899

}

764

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

900

int ret = start_mandos_communication(ip, port, interface,

901

avahi_proto_to_af(proto));

765

902

if(ret == 0){

766

avahi_simple_poll_quit(mc->simple_poll);

903

avahi_simple_poll_quit(mc.simple_poll);

767

904

}

768

905

}

769

906

}

779

916

const char *domain,

780

917

AVAHI_GCC_UNUSED AvahiLookupResultFlags

781

918

flags,

782

void* userdata){

783

mandos_context *mc = userdata;

919

AVAHI_GCC_UNUSED void* userdata){

784

920

assert(b);

785

921

786

922

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

787

923

is removed from the LAN */

788

924

925

if(quit_now){

926

return;

927

}

928

789

929

switch(event){

790

930

default:

791

931

case AVAHI_BROWSER_FAILURE:

792

932

793

933

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

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

934

avahi_strerror(avahi_server_errno(mc.server)));

935

avahi_simple_poll_quit(mc.simple_poll);

796

936

return;

797

937

798

938

case AVAHI_BROWSER_NEW:

801

941

the callback function is called the Avahi server will free the

802

942

resolver for us. */

803

943

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

944

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

945

name, type, domain, protocol, 0,

946

resolve_callback, NULL) == NULL)

808

947

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

809

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

948

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

810

949

break;

811

950

812

951

case AVAHI_BROWSER_REMOVE:

821

960

}

822

961

}

823

962

963

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

964

static void handle_sigterm(int sig){

965

if(quit_now){

966

return;

967

}

968

quit_now = 1;

969

signal_received = sig;

970

int old_errno = errno;

971

if(mc.simple_poll != NULL){

972

avahi_simple_poll_quit(mc.simple_poll);

973

}

974

errno = old_errno;

975

}

976

824

977

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

825

978

AvahiSServiceBrowser *sb = NULL;

826

979

int error;

827

980

int ret;

828

981

intmax_t tmpmax;

829

int numchars;

982

char *tmp;

830

983

int exitcode = EXIT_SUCCESS;

831

984

const char *interface = "eth0";

832

985

struct ifreq network;

833

int sd;

986

int sd = -1;

987

bool take_down_interface = false;

834

988

uid_t uid;

835

989

gid_t gid;

836

990

char *connect_to = NULL;

840

994

const char *seckey = PATHDIR "/" SECKEY;

841

995

const char *pubkey = PATHDIR "/" PUBKEY;

842

996

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

846

997

bool gnutls_initialized = false;

847

998

bool gpgme_initialized = false;

848

double delay = 2.5;

999

float delay = 2.5f;

1000

1001

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1002

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1003

1004

uid = getuid();

1005

gid = getgid();

1006

1007

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

1008

errno = 0;

1009

ret = setgid(gid);

1010

if(ret == -1){

1011

perror("setgid");

1012

}

1013

1014

/* Lower user privileges (temporarily) */

1015

errno = 0;

1016

ret = seteuid(uid);

1017

if(ret == -1){

1018

perror("seteuid");

1019

}

1020

1021

if(quit_now){

1022

goto end;

1023

}

849

1024

850

1025

{

851

1026

struct argp_option options[] = {

857

1032

.group = 1 },

858

1033

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

859

1034

.arg = "NAME",

860

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

861

" servers",

1035

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

1036

" Mandos servers",

862

1037

.group = 1 },

863

1038

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

864

1039

.arg = "FILE",

903

1078

pubkey = arg;

904

1079

break;

905

1080

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'){

1081

errno = 0;

1082

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

1083

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

1084

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

909

1085

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

910

1086

exit(EXIT_FAILURE);

911

1087

}

915

1091

mc.priority = arg;

916

1092

break;

917

1093

case 131: /* --delay */

918

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

919

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

1094

errno = 0;

1095

delay = strtof(arg, &tmp);

1096

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

920

1097

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

921

1098

exit(EXIT_FAILURE);

922

1099

}

943

1120

}

944

1121

}

945

1122

1123

if(not debug){

1124

avahi_set_log_function(empty_log);

1125

}

1126

1127

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

1128

from the signal handler */

1129

/* Initialize the pseudo-RNG for Avahi */

1130

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

1131

mc.simple_poll = avahi_simple_poll_new();

1132

if(mc.simple_poll == NULL){

1133

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

1134

exitcode = EXIT_FAILURE;

1135

goto end;

1136

}

1137

1138

sigemptyset(&sigterm_action.sa_mask);

1139

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

1140

if(ret == -1){

1141

perror("sigaddset");

1142

exitcode = EXIT_FAILURE;

1143

goto end;

1144

}

1145

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

1146

if(ret == -1){

1147

perror("sigaddset");

1148

exitcode = EXIT_FAILURE;

1149

goto end;

1150

}

1151

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

1152

if(ret == -1){

1153

perror("sigaddset");

1154

exitcode = EXIT_FAILURE;

1155

goto end;

1156

}

1157

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

1158

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

1159

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

1160

*/

1161

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

1162

if(ret == -1){

1163

perror("sigaction");

1164

return EXIT_FAILURE;

1165

}

1166

if(old_sigterm_action.sa_handler != SIG_IGN){

1167

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

1168

if(ret == -1){

1169

perror("sigaction");

1170

exitcode = EXIT_FAILURE;

1171

goto end;

1172

}

1173

}

1174

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

1175

if(ret == -1){

1176

perror("sigaction");

1177

return EXIT_FAILURE;

1178

}

1179

if(old_sigterm_action.sa_handler != SIG_IGN){

1180

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

1181

if(ret == -1){

1182

perror("sigaction");

1183

exitcode = EXIT_FAILURE;

1184

goto end;

1185

}

1186

}

1187

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

1188

if(ret == -1){

1189

perror("sigaction");

1190

return EXIT_FAILURE;

1191

}

1192

if(old_sigterm_action.sa_handler != SIG_IGN){

1193

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

1194

if(ret == -1){

1195

perror("sigaction");

1196

exitcode = EXIT_FAILURE;

1197

goto end;

1198

}

1199

}

1200

946

1201

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

947

{

1202

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

1203

if_index = (AvahiIfIndex) if_nametoindex(interface);

1204

if(if_index == 0){

1205

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

1206

exitcode = EXIT_FAILURE;

1207

goto end;

1208

}

1209

1210

if(quit_now){

1211

goto end;

1212

}

1213

1214

/* Re-raise priviliges */

1215

errno = 0;

1216

ret = seteuid(0);

1217

if(ret == -1){

1218

perror("seteuid");

1219

}

1220

948

1221

#ifdef __linux__

949

1222

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

950

1223

messages to mess up the prompt */

951

1224

ret = klogctl(8, NULL, 5);

1225

bool restore_loglevel = true;

952

1226

if(ret == -1){

1227

restore_loglevel = false;

953

1228

perror("klogctl");

954

1229

}

955

#endif

1230

#endif /* __linux__ */

956

1231

957

1232

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

958

1233

if(sd < 0){

959

1234

perror("socket");

960

1235

exitcode = EXIT_FAILURE;

961

1236

#ifdef __linux__

962

ret = klogctl(7, NULL, 0);

1237

if(restore_loglevel){

1238

ret = klogctl(7, NULL, 0);

1239

if(ret == -1){

1240

perror("klogctl");

1241

}

1242

}

1243

#endif /* __linux__ */

1244

/* Lower privileges */

1245

errno = 0;

1246

ret = seteuid(uid);

963

1247

if(ret == -1){

964

perror("klogctl");

1248

perror("seteuid");

965

1249

}

966

#endif

967

1250

goto end;

968

1251

}

969

1252

strcpy(network.ifr_name, interface);

971

1254

if(ret == -1){

972

1255

perror("ioctl SIOCGIFFLAGS");

973

1256

#ifdef __linux__

974

ret = klogctl(7, NULL, 0);

1257

if(restore_loglevel){

1258

ret = klogctl(7, NULL, 0);

1259

if(ret == -1){

1260

perror("klogctl");

1261

}

1262

}

1263

#endif /* __linux__ */

1264

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

975

1268

if(ret == -1){

976

perror("klogctl");

1269

perror("seteuid");

977

1270

}

978

#endif

979

exitcode = EXIT_FAILURE;

980

1271

goto end;

981

1272

}

982

1273

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

983

1274

network.ifr_flags |= IFF_UP;

1275

take_down_interface = true;

984

1276

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

985

1277

if(ret == -1){

1278

take_down_interface = false;

986

1279

perror("ioctl SIOCSIFFLAGS");

987

1280

exitcode = EXIT_FAILURE;

988

1281

#ifdef __linux__

989

ret = klogctl(7, NULL, 0);

1282

if(restore_loglevel){

1283

ret = klogctl(7, NULL, 0);

1284

if(ret == -1){

1285

perror("klogctl");

1286

}

1287

}

1288

#endif /* __linux__ */

1289

/* Lower privileges */

1290

errno = 0;

1291

ret = seteuid(uid);

990

1292

if(ret == -1){

991

perror("klogctl");

1293

perror("seteuid");

992

1294

}

993

#endif

994

1295

goto end;

995

1296

}

996

1297

}

1008

1309

perror("nanosleep");

1009

1310

}

1010

1311

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1312

if(not take_down_interface){

1313

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

1314

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

1315

if(ret == -1){

1316

perror("close");

1317

}

1014

1318

}

1015

1319

#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);

1320

if(restore_loglevel){

1321

/* Restores kernel loglevel to default */

1322

ret = klogctl(7, NULL, 0);

1323

if(ret == -1){

1324

perror("klogctl");

1325

}

1326

}

1327

#endif /* __linux__ */

1328

/* Lower privileges */

1329

errno = 0;

1330

if(take_down_interface){

1331

/* Lower privileges */

1332

ret = seteuid(uid);

1333

if(ret == -1){

1334

perror("seteuid");

1335

}

1336

} else {

1337

/* Lower privileges permanently */

1338

ret = setuid(uid);

1339

if(ret == -1){

1340

perror("setuid");

1341

}

1342

}

1343

}

1344

1345

if(quit_now){

1346

goto end;

1347

}

1348

1349

ret = init_gnutls_global(pubkey, seckey);

1038

1350

if(ret == -1){

1039

1351

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

1040

1352

exitcode = EXIT_FAILURE;

1043

1355

gnutls_initialized = true;

1044

1356

}

1045

1357

1358

if(quit_now){

1359

goto end;

1360

}

1361

1362

tempdir_created = true;

1046

1363

if(mkdtemp(tempdir) == NULL){

1364

tempdir_created = false;

1047

1365

perror("mkdtemp");

1048

1366

goto end;

1049

1367

}

1050

tempdir_created = true;

1051

1052

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

1368

1369

if(quit_now){

1370

goto end;

1371

}

1372

1373

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

1053

1374

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

1054

1375

exitcode = EXIT_FAILURE;

1055

1376

goto end;

1057

1378

gpgme_initialized = true;

1058

1379

}

1059

1380

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;

1381

if(quit_now){

1064

1382

goto end;

1065

1383

}

1066

1384

1073

1391

exitcode = EXIT_FAILURE;

1074

1392

goto end;

1075

1393

}

1394

1395

if(quit_now){

1396

goto end;

1397

}

1398

1076

1399

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'){

1400

errno = 0;

1401

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

1402

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

1403

or tmpmax != (uint16_t)tmpmax){

1080

1404

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

1081

1405

exitcode = EXIT_FAILURE;

1082

1406

goto end;

1083

1407

}

1408

1409

if(quit_now){

1410

goto end;

1411

}

1412

1084

1413

port = (uint16_t)tmpmax;

1085

1414

*address = '\0';

1086

1415

address = connect_to;

1087

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

1416

/* Colon in address indicates IPv6 */

1417

int af;

1418

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

1419

af = AF_INET6;

1420

} else {

1421

af = AF_INET;

1422

}

1423

1424

if(quit_now){

1425

goto end;

1426

}

1427

1428

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

1088

1429

if(ret < 0){

1089

1430

exitcode = EXIT_FAILURE;

1090

1431

} else {

1093

1434

goto end;

1094

1435

}

1095

1436

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;

1437

if(quit_now){

1108

1438

goto end;

1109

1439

}

1110

1440

1134

1464

goto end;

1135

1465

}

1136

1466

1467

if(quit_now){

1468

goto end;

1469

}

1470

1137

1471

/* Create the Avahi service browser */

1138

1472

sb = avahi_s_service_browser_new(mc.server, if_index,

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1473

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1474

NULL, 0, browse_callback, NULL);

1141

1475

if(sb == NULL){

1142

1476

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

1143

1477

avahi_strerror(avahi_server_errno(mc.server)));

1145

1479

goto end;

1146

1480

}

1147

1481

1482

if(quit_now){

1483

goto end;

1484

}

1485

1148

1486

/* Run the main loop */

1149

1487

1150

1488

if(debug){

1179

1517

gpgme_release(mc.ctx);

1180

1518

}

1181

1519

1520

/* Take down the network interface */

1521

if(take_down_interface){

1522

/* Re-raise priviliges */

1523

errno = 0;

1524

ret = seteuid(0);

1525

if(ret == -1){

1526

perror("seteuid");

1527

}

1528

if(geteuid() == 0){

1529

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

1530

if(ret == -1){

1531

perror("ioctl SIOCGIFFLAGS");

1532

} else if(network.ifr_flags & IFF_UP) {

1533

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

1534

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

1535

if(ret == -1){

1536

perror("ioctl SIOCSIFFLAGS");

1537

}

1538

}

1539

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

1540

if(ret == -1){

1541

perror("close");

1542

}

1543

/* Lower privileges permanently */

1544

errno = 0;

1545

ret = setuid(uid);

1546

if(ret == -1){

1547

perror("setuid");

1548

}

1549

}

1550

}

1551

1182

1552

/* Removes the temp directory used by GPGME */

1183

1553

if(tempdir_created){

1184

1554

DIR *d;

1223

1593

}

1224

1594

}

1225

1595

1596

if(quit_now){

1597

sigemptyset(&old_sigterm_action.sa_mask);

1598

old_sigterm_action.sa_handler = SIG_DFL;

1599

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1600

&old_sigterm_action,

1601

NULL));

1602

if(ret == -1){

1603

perror("sigaction");

1604

}

1605

do {

1606

ret = raise(signal_received);

1607

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

1608

if(ret != 0){

1609

perror("raise");

1610

abort();

1611

}

1612

TEMP_FAILURE_RETRY(pause());

1613

}

1614

1226

1615

return exitcode;

1227

1616

}