/mandos/release : revision 237.2.65

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

34

33

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

34

#define _FILE_OFFSET_BITS 64

38

#endif

39

35

40

36

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

41

37

42

38

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

43

stdout, ferror(), remove() */

39

stdout, ferror(), sscanf(),

40

remove() */

44

41

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

45

42

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

46

43

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

47

srand(), strtof() */

48

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

44

srand() */

45

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

49

46

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

50

47

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

51

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

48

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

52

49

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

53

50

sockaddr_in6, PF_INET6,

54

SOCK_STREAM, uid_t, gid_t, open(),

55

opendir(), DIR */

51

SOCK_STREAM, INET6_ADDRSTRLEN,

52

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

53

DIR */

56

54

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

57

55

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

58

inet_pton(), connect() */

56

struct in6_addr, inet_pton(),

57

connect() */

59

58

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

60

59

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

61

60

*/

62

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

63

strtoimax() */

61

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

64

62

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

65

63

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

66

64

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

67

65

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

68

66

SIOCSIFFLAGS, if_indextoname(),

69

67

if_nametoindex(), IF_NAMESIZE */

70

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

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

68

#include <netinet/in.h>

73

69

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

74

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

70

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

75

71

setgid() */

76

72

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

77

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

73

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

78

74

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

79

75

argp_state, struct argp,

80

76

argp_parse(), ARGP_KEY_ARG,

81

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

86

78

#ifdef __linux__

87

79

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

88

#endif /* __linux__ */

80

#endif

89

81

90

82

/* Avahi */

91

83

/* All Avahi types, constants and functions

137

129

gpgme_ctx_t ctx;

138

130

} mandos_context;

139

131

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

148

132

/*

149

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

150

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

133

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

134

* "buffer_capacity" is how much is currently allocated,

151

135

* "buffer_length" is how much is already used.

152

136

*/

153

size_t incbuffer(char **buffer, size_t buffer_length,

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

154

138

size_t buffer_capacity){

155

139

if(buffer_length + BUFFER_SIZE > buffer_capacity){

156

140

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

165

149

/*

166

150

* Initialize GPGME.

167

151

*/

168

static bool init_gpgme(const char *seckey,

152

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

169

153

const char *pubkey, const char *tempdir){

154

int ret;

170

155

gpgme_error_t rc;

171

156

gpgme_engine_info_t engine_info;

172

157

175

160

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

176

161

*/

177

162

bool import_key(const char *filename){

178

int ret;

179

163

int fd;

180

164

gpgme_data_t pgp_data;

181

165

192

176

return false;

193

177

}

194

178

195

rc = gpgme_op_import(mc.ctx, pgp_data);

179

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

196

180

if(rc != GPG_ERR_NO_ERROR){

197

181

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

198

182

gpgme_strsource(rc), gpgme_strerror(rc));

208

192

}

209

193

210

194

if(debug){

211

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

195

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

212

196

}

213

197

214

198

/* Init GPGME */

241

225

}

242

226

243

227

/* Create new GPGME "context" */

244

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

228

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

245

229

if(rc != GPG_ERR_NO_ERROR){

246

230

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

247

231

gpgme_strsource(rc), gpgme_strerror(rc));

252

236

return false;

253

237

}

254

238

255

return true;

239

return true;

256

240

}

257

241

258

242

/*

259

243

* Decrypt OpenPGP data.

260

244

* Returns -1 on error

261

245

*/

262

static ssize_t pgp_packet_decrypt(const char *cryptotext,

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

263

248

size_t crypto_size,

264

249

char **plaintext){

265

250

gpgme_data_t dh_crypto, dh_plain;

292

277

293

278

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

294

279

data buffer */

295

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

280

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

296

281

if(rc != GPG_ERR_NO_ERROR){

297

282

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

298

283

gpgme_strsource(rc), gpgme_strerror(rc));

299

284

plaintext_length = -1;

300

285

if(debug){

301

286

gpgme_decrypt_result_t result;

302

result = gpgme_op_decrypt_result(mc.ctx);

287

result = gpgme_op_decrypt_result(mc->ctx);

303

288

if(result == NULL){

304

289

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

305

290

} else {

312

297

}

313

298

gpgme_recipient_t recipient;

314

299

recipient = result->recipients;

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;

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

}

323

310

}

324

311

}

325

312

}

339

326

340

327

*plaintext = NULL;

341

328

while(true){

342

plaintext_capacity = incbuffer(plaintext,

329

plaintext_capacity = adjustbuffer(plaintext,

343

330

(size_t)plaintext_length,

344

331

plaintext_capacity);

345

332

if(plaintext_capacity == 0){

346

perror("incbuffer");

333

perror("adjustbuffer");

347

334

plaintext_length = -1;

348

335

goto decrypt_end;

349

336

}

395

382

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

396

383

}

397

384

398

static int init_gnutls_global(const char *pubkeyfilename,

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

399

387

const char *seckeyfilename){

400

388

int ret;

401

389

419

407

}

420

408

421

409

/* OpenPGP credentials */

422

gnutls_certificate_allocate_credentials(&mc.cred);

410

gnutls_certificate_allocate_credentials(&mc->cred);

423

411

if(ret != GNUTLS_E_SUCCESS){

424

412

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

425

from

426

-Wunreachable-code

427

*/

413

* from

414

* -Wunreachable-code

415

*/

428

416

safer_gnutls_strerror(ret));

429

417

gnutls_global_deinit();

430

418

return -1;

437

425

}

438

426

439

427

ret = gnutls_certificate_set_openpgp_key_file

440

(mc.cred, pubkeyfilename, seckeyfilename,

428

(mc->cred, pubkeyfilename, seckeyfilename,

441

429

GNUTLS_OPENPGP_FMT_BASE64);

442

430

if(ret != GNUTLS_E_SUCCESS){

443

431

fprintf(stderr,

449

437

}

450

438

451

439

/* GnuTLS server initialization */

452

ret = gnutls_dh_params_init(&mc.dh_params);

440

ret = gnutls_dh_params_init(&mc->dh_params);

453

441

if(ret != GNUTLS_E_SUCCESS){

454

442

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

455

443

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

456

444

goto globalfail;

457

445

}

458

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

446

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

459

447

if(ret != GNUTLS_E_SUCCESS){

460

448

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

461

449

safer_gnutls_strerror(ret));

462

450

goto globalfail;

463

451

}

464

452

465

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

453

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

466

454

467

455

return 0;

468

456

469

457

globalfail:

470

458

471

gnutls_certificate_free_credentials(mc.cred);

459

gnutls_certificate_free_credentials(mc->cred);

472

460

gnutls_global_deinit();

473

gnutls_dh_params_deinit(mc.dh_params);

461

gnutls_dh_params_deinit(mc->dh_params);

474

462

return -1;

475

463

}

476

464

477

static int init_gnutls_session(gnutls_session_t *session){

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

478

467

int ret;

479

468

/* GnuTLS session creation */

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);

469

ret = gnutls_init(session, GNUTLS_SERVER);

486

470

if(ret != GNUTLS_E_SUCCESS){

487

471

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

488

472

safer_gnutls_strerror(ret));

490

474

491

475

{

492

476

const char *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);

477

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

500

478

if(ret != GNUTLS_E_SUCCESS){

501

479

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

502

480

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

506

484

}

507

485

}

508

486

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);

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

517

489

if(ret != GNUTLS_E_SUCCESS){

518

490

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

519

491

safer_gnutls_strerror(ret));

522

494

}

523

495

524

496

/* ignore client certificate if any. */

525

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

526

499

527

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

528

501

529

502

return 0;

530

503

}

536

509

/* Called when a Mandos server is found */

537

510

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

538

511

AvahiIfIndex if_index,

539

int af){

540

int ret, tcp_sd = -1;

512

mandos_context *mc){

513

int ret, tcp_sd;

541

514

ssize_t sret;

542

union {

543

struct sockaddr_in in;

544

struct sockaddr_in6 in6;

545

} to;

515

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

546

516

char *buffer = NULL;

547

char *decrypted_buffer = NULL;

517

char *decrypted_buffer;

548

518

size_t buffer_length = 0;

549

519

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

550

521

size_t written;

551

int retval = -1;

522

int retval = 0;

523

char interface[IF_NAMESIZE];

552

524

gnutls_session_t 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);

525

526

ret = init_gnutls_session(mc, &session);

572

527

if(ret != 0){

573

528

return -1;

574

529

}

575

530

576

531

if(debug){

577

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

532

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

578

533

"\n", ip, port);

579

534

}

580

535

581

tcp_sd = socket(pf, SOCK_STREAM, 0);

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

582

537

if(tcp_sd < 0){

583

538

perror("socket");

584

goto mandos_end;

539

return -1;

585

540

}

586

541

587

if(quit_now){

588

goto mandos_end;

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);

589

548

}

590

549

591

550

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

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

}

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);

599

555

if(ret < 0 ){

600

556

perror("inet_pton");

601

goto mandos_end;

557

return -1;

602

558

}

603

559

if(ret == 0){

604

560

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

605

goto mandos_end;

561

return -1;

606

562

}

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

563

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

625

564

-Wconversion and

626

565

-Wunreachable-code */

627

}

628

566

629

if(quit_now){

630

goto mandos_end;

631

}

567

to.in6.sin6_scope_id = (uint32_t)if_index;

632

568

633

569

if(debug){

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){

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){

657

575

perror("inet_ntop");

658

576

} else {

659

577

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

662

580

}

663

581

}

664

582

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

}

583

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

674

584

if(ret < 0){

675

585

perror("connect");

676

goto mandos_end;

677

}

678

679

if(quit_now){

680

goto mandos_end;

586

return -1;

681

587

}

682

588

683

589

const char *out = mandos_protocol_version;

688

594

out_size - written));

689

595

if(ret == -1){

690

596

perror("write");

597

retval = -1;

691

598

goto mandos_end;

692

599

}

693

600

written += (size_t)ret;

701

608

break;

702

609

}

703

610

}

704

705

if(quit_now){

706

goto mandos_end;

707

}

708

611

}

709

612

710

613

if(debug){

711

614

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

712

615

}

713

616

714

if(quit_now){

715

goto mandos_end;

716

}

717

718

617

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

719

618

720

if(quit_now){

721

goto mandos_end;

722

}

723

724

do {

619

do{

725

620

ret = gnutls_handshake(session);

726

if(quit_now){

727

goto mandos_end;

728

}

729

621

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

730

622

731

623

if(ret != GNUTLS_E_SUCCESS){

733

625

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

734

626

gnutls_perror(ret);

735

627

}

628

retval = -1;

736

629

goto mandos_end;

737

630

}

738

631

739

632

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

740

633

741

634

if(debug){

742

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

635

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

743

636

ip);

744

637

}

745

638

746

639

while(true){

747

748

if(quit_now){

749

goto mandos_end;

750

}

751

752

buffer_capacity = incbuffer(&buffer, buffer_length,

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

753

641

buffer_capacity);

754

642

if(buffer_capacity == 0){

755

perror("incbuffer");

756

goto mandos_end;

757

}

758

759

if(quit_now){

643

perror("adjustbuffer");

644

retval = -1;

760

645

goto mandos_end;

761

646

}

762

647

771

656

case GNUTLS_E_AGAIN:

772

657

break;

773

658

case GNUTLS_E_REHANDSHAKE:

774

do {

659

do{

775

660

ret = gnutls_handshake(session);

776

777

if(quit_now){

778

goto mandos_end;

779

}

780

661

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

781

662

if(ret < 0){

782

663

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

783

664

gnutls_perror(ret);

665

retval = -1;

784

666

goto mandos_end;

785

667

}

786

668

break;

787

669

default:

788

670

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

789

671

" encrypted session with Mandos server\n");

672

retval = -1;

790

673

gnutls_bye(session, GNUTLS_SHUT_RDWR);

791

674

goto mandos_end;

792

675

}

799

682

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

800

683

}

801

684

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);

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

812

686

813

687

if(buffer_length > 0){

814

ssize_t decrypted_buffer_size;

815

decrypted_buffer_size = pgp_packet_decrypt(buffer,

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

816

689

buffer_length,

817

690

&decrypted_buffer);

818

691

if(decrypted_buffer_size >= 0){

819

820

692

written = 0;

821

693

while(written < (size_t) decrypted_buffer_size){

822

if(quit_now){

823

goto mandos_end;

824

}

825

826

694

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

827

695

(size_t)decrypted_buffer_size - written,

828

696

stdout);

831

699

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

832

700

strerror(errno));

833

701

}

834

goto mandos_end;

702

retval = -1;

703

break;

835

704

}

836

705

written += (size_t)ret;

837

706

}

838

retval = 0;

707

free(decrypted_buffer);

708

} else {

709

retval = -1;

839

710

}

711

} else {

712

retval = -1;

840

713

}

841

714

842

715

/* Shutdown procedure */

843

716

844

717

mandos_end:

845

free(decrypted_buffer);

846

718

free(buffer);

847

if(tcp_sd >= 0){

848

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

849

}

719

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

850

720

if(ret == -1){

851

721

perror("close");

852

722

}

853

723

gnutls_deinit(session);

854

if(quit_now){

855

retval = -1;

856

}

857

724

return retval;

858

725

}

859

726

860

727

static void resolve_callback(AvahiSServiceResolver *r,

861

728

AvahiIfIndex interface,

862

AvahiProtocol proto,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

863

730

AvahiResolverEvent event,

864

731

const char *name,

865

732

const char *type,

870

737

AVAHI_GCC_UNUSED AvahiStringList *txt,

871

738

AVAHI_GCC_UNUSED AvahiLookupResultFlags

872

739

flags,

873

AVAHI_GCC_UNUSED void* userdata){

740

void* userdata){

741

mandos_context *mc = userdata;

874

742

assert(r);

875

743

876

744

/* Called whenever a service has been resolved successfully or

877

745

timed out */

878

746

879

if(quit_now){

880

return;

881

}

882

883

747

switch(event){

884

748

default:

885

749

case AVAHI_RESOLVER_FAILURE:

886

750

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

887

751

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

888

avahi_strerror(avahi_server_errno(mc.server)));

752

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

889

753

break;

890

754

891

755

case AVAHI_RESOLVER_FOUND:

897

761

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

898

762

ip, (intmax_t)interface, port);

899

763

}

900

int ret = start_mandos_communication(ip, port, interface,

901

avahi_proto_to_af(proto));

764

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

902

765

if(ret == 0){

903

avahi_simple_poll_quit(mc.simple_poll);

766

avahi_simple_poll_quit(mc->simple_poll);

904

767

}

905

768

}

906

769

}

916

779

const char *domain,

917

780

AVAHI_GCC_UNUSED AvahiLookupResultFlags

918

781

flags,

919

AVAHI_GCC_UNUSED void* userdata){

782

void* userdata){

783

mandos_context *mc = userdata;

920

784

assert(b);

921

785

922

786

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

923

787

is removed from the LAN */

924

788

925

if(quit_now){

926

return;

927

}

928

929

789

switch(event){

930

790

default:

931

791

case AVAHI_BROWSER_FAILURE:

932

792

933

793

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

934

avahi_strerror(avahi_server_errno(mc.server)));

935

avahi_simple_poll_quit(mc.simple_poll);

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

936

796

return;

937

797

938

798

case AVAHI_BROWSER_NEW:

941

801

the callback function is called the Avahi server will free the

942

802

resolver for us. */

943

803

944

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

945

name, type, domain, protocol, 0,

946

resolve_callback, NULL) == NULL)

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

947

808

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

948

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

809

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

949

810

break;

950

811

951

812

case AVAHI_BROWSER_REMOVE:

960

821

}

961

822

}

962

823

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

977

824

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

978

825

AvahiSServiceBrowser *sb = NULL;

979

826

int error;

980

827

int ret;

981

828

intmax_t tmpmax;

982

char *tmp;

829

int numchars;

983

830

int exitcode = EXIT_SUCCESS;

984

831

const char *interface = "eth0";

985

832

struct ifreq network;

986

int sd = -1;

987

bool take_down_interface = false;

833

int sd;

988

834

uid_t uid;

989

835

gid_t gid;

990

836

char *connect_to = NULL;

994

840

const char *seckey = PATHDIR "/" SECKEY;

995

841

const char *pubkey = PATHDIR "/" PUBKEY;

996

842

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

997

846

bool gnutls_initialized = false;

998

847

bool gpgme_initialized = false;

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

}

848

double delay = 2.5;

1024

849

1025

850

{

1026

851

struct argp_option options[] = {

1032

857

.group = 1 },

1033

858

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

1034

859

.arg = "NAME",

1035

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

1036

" Mandos servers",

860

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

861

" servers",

1037

862

.group = 1 },

1038

863

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

1039

864

.arg = "FILE",

1078

903

pubkey = arg;

1079

904

break;

1080

905

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

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){

906

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

907

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

908

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

1085

909

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

1086

910

exit(EXIT_FAILURE);

1087

911

}

1091

915

mc.priority = arg;

1092

916

break;

1093

917

case 131: /* --delay */

1094

errno = 0;

1095

delay = strtof(arg, &tmp);

1096

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

918

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

919

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

1097

920

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

1098

921

exit(EXIT_FAILURE);

1099

922

}

1120

943

}

1121

944

}

1122

945

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

1201

946

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

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

947

{

1221

948

#ifdef __linux__

1222

949

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1223

950

messages to mess up the prompt */

1224

951

ret = klogctl(8, NULL, 5);

1225

bool restore_loglevel = true;

1226

952

if(ret == -1){

1227

restore_loglevel = false;

1228

953

perror("klogctl");

1229

954

}

1230

#endif /* __linux__ */

955

#endif

1231

956

1232

957

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1233

958

if(sd < 0){

1234

959

perror("socket");

1235

960

exitcode = EXIT_FAILURE;

1236

961

#ifdef __linux__

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);

962

ret = klogctl(7, NULL, 0);

1247

963

if(ret == -1){

1248

perror("seteuid");

964

perror("klogctl");

1249

965

}

966

#endif

1250

967

goto end;

1251

968

}

1252

969

strcpy(network.ifr_name, interface);

1254

971

if(ret == -1){

1255

972

perror("ioctl SIOCGIFFLAGS");

1256

973

#ifdef __linux__

1257

if(restore_loglevel){

1258

ret = klogctl(7, NULL, 0);

1259

if(ret == -1){

1260

perror("klogctl");

1261

}

974

ret = klogctl(7, NULL, 0);

975

if(ret == -1){

976

perror("klogctl");

1262

977

}

1263

#endif /* __linux__ */

978

#endif

1264

979

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

1268

if(ret == -1){

1269

perror("seteuid");

1270

}

1271

980

goto end;

1272

981

}

1273

982

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

1274

983

network.ifr_flags |= IFF_UP;

1275

take_down_interface = true;

1276

984

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

1277

985

if(ret == -1){

1278

take_down_interface = false;

1279

986

perror("ioctl SIOCSIFFLAGS");

1280

987

exitcode = EXIT_FAILURE;

1281

988

#ifdef __linux__

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);

989

ret = klogctl(7, NULL, 0);

1292

990

if(ret == -1){

1293

perror("seteuid");

991

perror("klogctl");

1294

992

}

993

#endif

1295

994

goto end;

1296

995

}

1297

996

}

1309

1008

perror("nanosleep");

1310

1009

}

1311

1010

}

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

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1318

1014

}

1319

1015

#ifdef __linux__

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);

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);

1350

1038

if(ret == -1){

1351

1039

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

1352

1040

exitcode = EXIT_FAILURE;

1355

1043

gnutls_initialized = true;

1356

1044

}

1357

1045

1358

if(quit_now){

1359

goto end;

1360

}

1361

1362

tempdir_created = true;

1363

1046

if(mkdtemp(tempdir) == NULL){

1364

tempdir_created = false;

1365

1047

perror("mkdtemp");

1366

1048

goto end;

1367

1049

}

1368

1369

if(quit_now){

1370

goto end;

1371

}

1372

1373

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

1050

tempdir_created = true;

1051

1052

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

1374

1053

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

1375

1054

exitcode = EXIT_FAILURE;

1376

1055

goto end;

1378

1057

gpgme_initialized = true;

1379

1058

}

1380

1059

1381

if(quit_now){

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;

1382

1064

goto end;

1383

1065

}

1384

1066

1391

1073

exitcode = EXIT_FAILURE;

1392

1074

goto end;

1393

1075

}

1394

1395

if(quit_now){

1396

goto end;

1397

}

1398

1399

1076

uint16_t port;

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){

1077

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

1078

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

1079

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

1404

1080

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

1405

1081

exitcode = EXIT_FAILURE;

1406

1082

goto end;

1407

1083

}

1408

1409

if(quit_now){

1410

goto end;

1411

}

1412

1413

1084

port = (uint16_t)tmpmax;

1414

1085

*address = '\0';

1415

1086

address = connect_to;

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);

1087

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

1429

1088

if(ret < 0){

1430

1089

exitcode = EXIT_FAILURE;

1431

1090

} else {

1434

1093

goto end;

1435

1094

}

1436

1095

1437

if(quit_now){

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;

1438

1108

goto end;

1439

1109

}

1440

1110

1464

1134

goto end;

1465

1135

}

1466

1136

1467

if(quit_now){

1468

goto end;

1469

}

1470

1471

1137

/* Create the Avahi service browser */

1472

1138

sb = avahi_s_service_browser_new(mc.server, if_index,

1473

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1474

NULL, 0, browse_callback, NULL);

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1475

1141

if(sb == NULL){

1476

1142

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

1477

1143

avahi_strerror(avahi_server_errno(mc.server)));

1479

1145

goto end;

1480

1146

}

1481

1147

1482

if(quit_now){

1483

goto end;

1484

}

1485

1486

1148

/* Run the main loop */

1487

1149

1488

1150

if(debug){

1517

1179

gpgme_release(mc.ctx);

1518

1180

}

1519

1181

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

1552

1182

/* Removes the temp directory used by GPGME */

1553

1183

if(tempdir_created){

1554

1184

DIR *d;

1593

1223

}

1594

1224

}

1595

1225

1596

if(quit_now){

1597

sigemptyset(&old_sigterm_action.sa_mask);

1598

old_sigterm_action.sa_handler = SIG_DFL;

1599

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

1600

if(ret == -1){

1601

perror("sigaction");

1602

}

1603

raise(signal_received);

1604

}

1605

1606

1226

return exitcode;

1607

1227

}