/mandos/release : revision 237.2.180

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

33

34

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

34

37

#define _FILE_OFFSET_BITS 64

38

#endif

35

39

36

40

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

37

41

38

42

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

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

42

45

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

43

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

44

srand() */

46

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

47

strtof(), abort() */

45

48

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

46

49

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

47

50

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

56

59

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

57

60

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

58

61

*/

59

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

62

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

63

strtoimax() */

60

64

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

61

65

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

62

66

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

67

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

68

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

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

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

86

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

87

78

88

#ifdef __linux__

79

89

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

80

#endif

90

#endif /* __linux__ */

81

91

82

92

/* Avahi */

83

93

/* All Avahi types, constants and functions

129

139

gpgme_ctx_t ctx;

130

140

} mandos_context;

131

141

142

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

143

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

144

.dh_bits = 1024, .priority = "SECURE256"

145

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

146

147

sig_atomic_t quit_now = 0;

148

int signal_received = 0;

149

132

150

/*

133

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

134

* "buffer_capacity" is how much is currently allocated,

151

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

152

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

135

153

* "buffer_length" is how much is already used.

136

154

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

155

size_t incbuffer(char **buffer, size_t buffer_length,

138

156

size_t buffer_capacity){

139

157

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

158

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

149

167

/*

150

168

* Initialize GPGME.

151

169

*/

152

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

170

static bool init_gpgme(const char *seckey,

153

171

const char *pubkey, const char *tempdir){

154

int ret;

155

172

gpgme_error_t rc;

156

173

gpgme_engine_info_t engine_info;

157

174

160

177

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

161

178

*/

162

179

bool import_key(const char *filename){

180

int ret;

163

181

int fd;

164

182

gpgme_data_t pgp_data;

165

183

176

194

return false;

177

195

}

178

196

179

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

197

rc = gpgme_op_import(mc.ctx, pgp_data);

180

198

if(rc != GPG_ERR_NO_ERROR){

181

199

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

182

200

gpgme_strsource(rc), gpgme_strerror(rc));

192

210

}

193

211

194

212

if(debug){

195

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

213

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

196

214

}

197

215

198

216

/* Init GPGME */

225

243

}

226

244

227

245

/* Create new GPGME "context" */

228

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

246

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

229

247

if(rc != GPG_ERR_NO_ERROR){

230

248

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

231

249

gpgme_strsource(rc), gpgme_strerror(rc));

236

254

return false;

237

255

}

238

256

239

return true;

257

return true;

240

258

}

241

259

242

260

/*

243

261

* Decrypt OpenPGP data.

244

262

* Returns -1 on error

245

263

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

264

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

265

size_t crypto_size,

249

266

char **plaintext){

250

267

gpgme_data_t dh_crypto, dh_plain;

277

294

278

295

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

279

296

data buffer */

280

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

297

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

281

298

if(rc != GPG_ERR_NO_ERROR){

282

299

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

283

300

gpgme_strsource(rc), gpgme_strerror(rc));

284

301

plaintext_length = -1;

285

302

if(debug){

286

303

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

304

result = gpgme_op_decrypt_result(mc.ctx);

288

305

if(result == NULL){

289

306

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

290

307

} else {

297

314

}

298

315

gpgme_recipient_t recipient;

299

316

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

}

317

while(recipient != NULL){

318

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

319

gpgme_pubkey_algo_name(recipient->pubkey_algo));

320

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

321

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

322

recipient->status == GPG_ERR_NO_SECKEY

323

? "No" : "Yes");

324

recipient = recipient->next;

310

325

}

311

326

}

312

327

}

326

341

327

342

*plaintext = NULL;

328

343

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

344

plaintext_capacity = incbuffer(plaintext,

330

345

(size_t)plaintext_length,

331

346

plaintext_capacity);

332

347

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

348

perror("incbuffer");

334

349

plaintext_length = -1;

335

350

goto decrypt_end;

336

351

}

382

397

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

383

398

}

384

399

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

400

static int init_gnutls_global(const char *pubkeyfilename,

387

401

const char *seckeyfilename){

388

402

int ret;

389

403

407

421

}

408

422

409

423

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

424

gnutls_certificate_allocate_credentials(&mc.cred);

411

425

if(ret != GNUTLS_E_SUCCESS){

412

426

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

413

427

from

425

439

}

426

440

427

441

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

442

(mc.cred, pubkeyfilename, seckeyfilename,

429

443

GNUTLS_OPENPGP_FMT_BASE64);

430

444

if(ret != GNUTLS_E_SUCCESS){

431

445

fprintf(stderr,

437

451

}

438

452

439

453

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

454

ret = gnutls_dh_params_init(&mc.dh_params);

441

455

if(ret != GNUTLS_E_SUCCESS){

442

456

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

443

457

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

444

458

goto globalfail;

445

459

}

446

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

460

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

447

461

if(ret != GNUTLS_E_SUCCESS){

448

462

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

449

463

safer_gnutls_strerror(ret));

450

464

goto globalfail;

451

465

}

452

466

453

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

467

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

468

455

469

return 0;

456

470

457

471

globalfail:

458

472

459

gnutls_certificate_free_credentials(mc->cred);

473

gnutls_certificate_free_credentials(mc.cred);

460

474

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

475

gnutls_dh_params_deinit(mc.dh_params);

462

476

return -1;

463

477

}

464

478

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

479

static int init_gnutls_session(gnutls_session_t *session){

467

480

int ret;

468

481

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

482

do {

483

ret = gnutls_init(session, GNUTLS_SERVER);

484

if(quit_now){

485

return -1;

486

}

487

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

470

488

if(ret != GNUTLS_E_SUCCESS){

471

489

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

472

490

safer_gnutls_strerror(ret));

474

492

475

493

{

476

494

const char *err;

477

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

495

do {

496

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

497

if(quit_now){

498

gnutls_deinit(*session);

499

return -1;

500

}

501

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

478

502

if(ret != GNUTLS_E_SUCCESS){

479

503

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

480

504

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

484

508

}

485

509

}

486

510

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

511

do {

512

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

513

mc.cred);

514

if(quit_now){

515

gnutls_deinit(*session);

516

return -1;

517

}

518

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

489

519

if(ret != GNUTLS_E_SUCCESS){

490

520

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

491

521

safer_gnutls_strerror(ret));

494

524

}

495

525

496

526

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

527

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

528

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

529

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

530

502

531

return 0;

503

532

}

509

538

/* Called when a Mandos server is found */

510

539

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

511

540

AvahiIfIndex if_index,

512

mandos_context *mc, int af){

513

int ret, tcp_sd;

541

int af){

542

int ret, tcp_sd = -1;

514

543

ssize_t sret;

515

544

union {

516

545

struct sockaddr_in in;

517

546

struct sockaddr_in6 in6;

518

547

} to;

519

548

char *buffer = NULL;

520

char *decrypted_buffer;

549

char *decrypted_buffer = NULL;

521

550

size_t buffer_length = 0;

522

551

size_t buffer_capacity = 0;

523

ssize_t decrypted_buffer_size;

524

552

size_t written;

525

int retval = 0;

553

int retval = -1;

526

554

gnutls_session_t session;

527

555

int pf; /* Protocol family */

528

556

557

errno = 0;

558

559

if(quit_now){

560

errno = EINTR;

561

return -1;

562

}

563

529

564

switch(af){

530

565

case AF_INET6:

531

566

pf = PF_INET6;

535

570

break;

536

571

default:

537

572

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

573

errno = EINVAL;

538

574

return -1;

539

575

}

540

576

541

ret = init_gnutls_session(mc, &session);

577

ret = init_gnutls_session(&session);

542

578

if(ret != 0){

543

579

return -1;

544

580

}

550

586

551

587

tcp_sd = socket(pf, SOCK_STREAM, 0);

552

588

if(tcp_sd < 0){

589

int e = errno;

553

590

perror("socket");

554

return -1;

591

errno = e;

592

goto mandos_end;

593

}

594

595

if(quit_now){

596

errno = EINTR;

597

goto mandos_end;

555

598

}

556

599

557

600

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

558

601

if(af == AF_INET6){

559

to.in6.sin6_family = (uint16_t)af;

602

to.in6.sin6_family = (sa_family_t)af;

560

603

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

561

604

} else { /* IPv4 */

562

605

to.in.sin_family = (sa_family_t)af;

563

606

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

564

607

}

565

608

if(ret < 0 ){

609

int e = errno;

566

610

perror("inet_pton");

567

return -1;

611

errno = e;

612

goto mandos_end;

568

613

}

569

614

if(ret == 0){

615

int e = errno;

570

616

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

571

return -1;

617

errno = e;

618

goto mandos_end;

572

619

}

573

620

if(af == AF_INET6){

574

621

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

581

628

if(if_index == AVAHI_IF_UNSPEC){

582

629

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

583

630

" without a network interface\n");

584

return -1;

631

errno = EINVAL;

632

goto mandos_end;

585

633

}

586

634

/* Set the network interface number as scope */

587

635

to.in6.sin6_scope_id = (uint32_t)if_index;

592

640

-Wunreachable-code */

593

641

}

594

642

643

if(quit_now){

644

errno = EINTR;

645

goto mandos_end;

646

}

647

595

648

if(debug){

596

649

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

597

650

char interface[IF_NAMESIZE];

624

677

}

625

678

}

626

679

680

if(quit_now){

681

errno = EINTR;

682

goto mandos_end;

683

}

684

627

685

if(af == AF_INET6){

628

686

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

629

687

} else {

630

688

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

631

689

}

632

690

if(ret < 0){

691

int e = errno;

633

692

perror("connect");

634

return -1;

693

errno = e;

694

goto mandos_end;

695

}

696

697

if(quit_now){

698

errno = EINTR;

699

goto mandos_end;

635

700

}

636

701

637

702

const char *out = mandos_protocol_version;

641

706

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

642

707

out_size - written));

643

708

if(ret == -1){

709

int e = errno;

644

710

perror("write");

645

retval = -1;

711

errno = e;

646

712

goto mandos_end;

647

713

}

648

714

written += (size_t)ret;

656

722

break;

657

723

}

658

724

}

725

726

if(quit_now){

727

errno = EINTR;

728

goto mandos_end;

729

}

659

730

}

660

731

661

732

if(debug){

662

733

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

663

734

}

664

735

736

if(quit_now){

737

errno = EINTR;

738

goto mandos_end;

739

}

740

665

741

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

666

742

667

do{

743

if(quit_now){

744

errno = EINTR;

745

goto mandos_end;

746

}

747

748

do {

668

749

ret = gnutls_handshake(session);

750

if(quit_now){

751

errno = EINTR;

752

goto mandos_end;

753

}

669

754

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

670

755

671

756

if(ret != GNUTLS_E_SUCCESS){

673

758

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

674

759

gnutls_perror(ret);

675

760

}

676

retval = -1;

761

errno = EPROTO;

677

762

goto mandos_end;

678

763

}

679

764

685

770

}

686

771

687

772

while(true){

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

773

774

if(quit_now){

775

errno = EINTR;

776

goto mandos_end;

777

}

778

779

buffer_capacity = incbuffer(&buffer, buffer_length,

689

780

buffer_capacity);

690

781

if(buffer_capacity == 0){

691

perror("adjustbuffer");

692

retval = -1;

782

int e = errno;

783

perror("incbuffer");

784

errno = e;

785

goto mandos_end;

786

}

787

788

if(quit_now){

789

errno = EINTR;

693

790

goto mandos_end;

694

791

}

695

792

704

801

case GNUTLS_E_AGAIN:

705

802

break;

706

803

case GNUTLS_E_REHANDSHAKE:

707

do{

804

do {

708

805

ret = gnutls_handshake(session);

806

807

if(quit_now){

808

errno = EINTR;

809

goto mandos_end;

810

}

709

811

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

710

812

if(ret < 0){

711

813

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

712

814

gnutls_perror(ret);

713

retval = -1;

815

errno = EPROTO;

714

816

goto mandos_end;

715

817

}

716

818

break;

717

819

default:

718

820

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

719

821

" encrypted session with Mandos server\n");

720

retval = -1;

721

822

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

errno = EIO;

722

824

goto mandos_end;

723

825

}

724

826

} else {

730

832

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

731

833

}

732

834

733

gnutls_bye(session, GNUTLS_SHUT_RDWR);

835

if(quit_now){

836

errno = EINTR;

837

goto mandos_end;

838

}

839

840

do {

841

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

842

if(quit_now){

843

errno = EINTR;

844

goto mandos_end;

845

}

846

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

734

847

735

848

if(buffer_length > 0){

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

849

ssize_t decrypted_buffer_size;

850

decrypted_buffer_size = pgp_packet_decrypt(buffer,

737

851

buffer_length,

738

852

&decrypted_buffer);

739

853

if(decrypted_buffer_size >= 0){

854

740

855

written = 0;

741

856

while(written < (size_t) decrypted_buffer_size){

857

if(quit_now){

858

errno = EINTR;

859

goto mandos_end;

860

}

861

742

862

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

743

863

(size_t)decrypted_buffer_size - written,

744

864

stdout);

745

865

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

866

int e = errno;

746

867

if(debug){

747

868

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

748

869

strerror(errno));

749

870

}

750

retval = -1;

751

break;

871

errno = e;

872

goto mandos_end;

752

873

}

753

874

written += (size_t)ret;

754

875

}

755

free(decrypted_buffer);

756

} else {

757

retval = -1;

876

retval = 0;

758

877

}

759

} else {

760

retval = -1;

761

878

}

762

879

763

880

/* Shutdown procedure */

764

881

765

882

mandos_end:

766

free(buffer);

767

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

768

if(ret == -1){

769

perror("close");

883

{

884

int e = errno;

885

free(decrypted_buffer);

886

free(buffer);

887

if(tcp_sd >= 0){

888

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

889

}

890

if(ret == -1){

891

if(e == 0){

892

e = errno;

893

}

894

perror("close");

895

}

896

gnutls_deinit(session);

897

if(quit_now){

898

e = EINTR;

899

retval = -1;

900

}

901

errno = e;

770

902

}

771

gnutls_deinit(session);

772

903

return retval;

773

904

}

774

905

785

916

AVAHI_GCC_UNUSED AvahiStringList *txt,

786

917

AVAHI_GCC_UNUSED AvahiLookupResultFlags

787

918

flags,

788

void* userdata){

789

mandos_context *mc = userdata;

919

AVAHI_GCC_UNUSED void* userdata){

790

920

assert(r);

791

921

792

922

/* Called whenever a service has been resolved successfully or

793

923

timed out */

794

924

925

if(quit_now){

926

return;

927

}

928

795

929

switch(event){

796

930

default:

797

931

case AVAHI_RESOLVER_FAILURE:

798

932

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

799

933

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

800

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

934

avahi_strerror(avahi_server_errno(mc.server)));

801

935

break;

802

936

803

937

case AVAHI_RESOLVER_FOUND:

809

943

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

810

944

ip, (intmax_t)interface, port);

811

945

}

812

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

946

int ret = start_mandos_communication(ip, port, interface,

813

947

avahi_proto_to_af(proto));

814

948

if(ret == 0){

815

avahi_simple_poll_quit(mc->simple_poll);

949

avahi_simple_poll_quit(mc.simple_poll);

816

950

}

817

951

}

818

952

}

828

962

const char *domain,

829

963

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

964

flags,

831

void* userdata){

832

mandos_context *mc = userdata;

965

AVAHI_GCC_UNUSED void* userdata){

833

966

assert(b);

834

967

835

968

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

836

969

is removed from the LAN */

837

970

971

if(quit_now){

972

return;

973

}

974

838

975

switch(event){

839

976

default:

840

977

case AVAHI_BROWSER_FAILURE:

841

978

842

979

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

843

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

844

avahi_simple_poll_quit(mc->simple_poll);

980

avahi_strerror(avahi_server_errno(mc.server)));

981

avahi_simple_poll_quit(mc.simple_poll);

845

982

return;

846

983

847

984

case AVAHI_BROWSER_NEW:

850

987

the callback function is called the Avahi server will free the

851

988

resolver for us. */

852

989

853

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

854

protocol, name, type, domain,

855

AVAHI_PROTO_INET6, 0,

856

resolve_callback, mc)))

990

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

991

name, type, domain, protocol, 0,

992

resolve_callback, NULL) == NULL)

857

993

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

858

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

994

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

859

995

break;

860

996

861

997

case AVAHI_BROWSER_REMOVE:

870

1006

}

871

1007

}

872

1008

1009

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

1010

static void handle_sigterm(int sig){

1011

if(quit_now){

1012

return;

1013

}

1014

quit_now = 1;

1015

signal_received = sig;

1016

int old_errno = errno;

1017

if(mc.simple_poll != NULL){

1018

avahi_simple_poll_quit(mc.simple_poll);

1019

}

1020

errno = old_errno;

1021

}

1022

873

1023

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

874

1024

AvahiSServiceBrowser *sb = NULL;

875

1025

int error;

876

1026

int ret;

877

1027

intmax_t tmpmax;

878

int numchars;

1028

char *tmp;

879

1029

int exitcode = EXIT_SUCCESS;

880

1030

const char *interface = "eth0";

881

1031

struct ifreq network;

882

int sd;

1032

int sd = -1;

1033

bool take_down_interface = false;

883

1034

uid_t uid;

884

1035

gid_t gid;

885

1036

char *connect_to = NULL;

889

1040

const char *seckey = PATHDIR "/" SECKEY;

890

1041

const char *pubkey = PATHDIR "/" PUBKEY;

891

1042

892

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

893

.dh_bits = 1024, .priority = "SECURE256"

894

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

895

1043

bool gnutls_initialized = false;

896

1044

bool gpgme_initialized = false;

897

double delay = 2.5;

1045

float delay = 2.5f;

1046

1047

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1048

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1049

1050

uid = getuid();

1051

gid = getgid();

1052

1053

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

1054

errno = 0;

1055

ret = setgid(gid);

1056

if(ret == -1){

1057

perror("setgid");

1058

}

1059

1060

/* Lower user privileges (temporarily) */

1061

errno = 0;

1062

ret = seteuid(uid);

1063

if(ret == -1){

1064

perror("seteuid");

1065

}

1066

1067

if(quit_now){

1068

goto end;

1069

}

898

1070

899

1071

{

900

1072

struct argp_option options[] = {

930

1102

.arg = "SECONDS",

931

1103

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

932

1104

.group = 2 },

1105

/*

1106

* These reproduce what we would get without ARGP_NO_HELP

1107

*/

1108

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

1109

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

1110

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

1111

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

1112

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

1113

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

933

1114

{ .name = NULL }

934

1115

};

935

1116

936

1117

error_t parse_opt(int key, char *arg,

937

1118

struct argp_state *state){

1119

errno = 0;

938

1120

switch(key){

939

1121

case 128: /* --debug */

940

1122

debug = true;

952

1134

pubkey = arg;

953

1135

break;

954

1136

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

955

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

956

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

957

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

958

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

959

exit(EXIT_FAILURE);

1137

errno = 0;

1138

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

1139

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

1140

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

1141

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

960

1142

}

961

1143

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

962

1144

break;

964

1146

mc.priority = arg;

965

1147

break;

966

1148

case 131: /* --delay */

967

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

968

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

969

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

970

exit(EXIT_FAILURE);

1149

errno = 0;

1150

delay = strtof(arg, &tmp);

1151

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

1152

argp_error(state, "Bad delay");

971

1153

}

972

1154

break;

973

case ARGP_KEY_ARG:

974

argp_usage(state);

975

case ARGP_KEY_END:

1155

/*

1156

* These reproduce what we would get without ARGP_NO_HELP

1157

*/

1158

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

1159

argp_state_help(state, state->out_stream,

1160

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1161

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1162

case -3: /* --usage */

1163

argp_state_help(state, state->out_stream,

1164

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1165

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

1166

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

1167

exit(argp_err_exit_status);

976

1168

break;

977

1169

default:

978

1170

return ARGP_ERR_UNKNOWN;

979

1171

}

980

return 0;

1172

return errno;

981

1173

}

982

1174

983

1175

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

984

1176

.args_doc = "",

985

1177

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

986

1178

" passwords from a Mandos server" };

987

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

988

if(ret == ARGP_ERR_UNKNOWN){

989

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

990

exitcode = EXIT_FAILURE;

1179

ret = argp_parse(&argp, argc, argv,

1180

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1181

switch(ret){

1182

case 0:

1183

break;

1184

case ENOMEM:

1185

default:

1186

errno = ret;

1187

perror("argp_parse");

1188

exitcode = EX_OSERR;

1189

goto end;

1190

case EINVAL:

1191

exitcode = EX_USAGE;

1192

goto end;

1193

}

1194

}

1195

1196

if(not debug){

1197

avahi_set_log_function(empty_log);

1198

}

1199

1200

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

1201

from the signal handler */

1202

/* Initialize the pseudo-RNG for Avahi */

1203

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

1204

mc.simple_poll = avahi_simple_poll_new();

1205

if(mc.simple_poll == NULL){

1206

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

1207

exitcode = EX_UNAVAILABLE;

1208

goto end;

1209

}

1210

1211

sigemptyset(&sigterm_action.sa_mask);

1212

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

1213

if(ret == -1){

1214

perror("sigaddset");

1215

exitcode = EX_OSERR;

1216

goto end;

1217

}

1218

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

1219

if(ret == -1){

1220

perror("sigaddset");

1221

exitcode = EX_OSERR;

1222

goto end;

1223

}

1224

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

1225

if(ret == -1){

1226

perror("sigaddset");

1227

exitcode = EX_OSERR;

1228

goto end;

1229

}

1230

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

1231

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

1232

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

1233

*/

1234

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

1235

if(ret == -1){

1236

perror("sigaction");

1237

return EX_OSERR;

1238

}

1239

if(old_sigterm_action.sa_handler != SIG_IGN){

1240

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

1241

if(ret == -1){

1242

perror("sigaction");

1243

exitcode = EX_OSERR;

1244

goto end;

1245

}

1246

}

1247

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

1248

if(ret == -1){

1249

perror("sigaction");

1250

return EX_OSERR;

1251

}

1252

if(old_sigterm_action.sa_handler != SIG_IGN){

1253

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

1254

if(ret == -1){

1255

perror("sigaction");

1256

exitcode = EX_OSERR;

1257

goto end;

1258

}

1259

}

1260

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

1261

if(ret == -1){

1262

perror("sigaction");

1263

return EX_OSERR;

1264

}

1265

if(old_sigterm_action.sa_handler != SIG_IGN){

1266

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

1267

if(ret == -1){

1268

perror("sigaction");

1269

exitcode = EX_OSERR;

991

1270

goto end;

992

1271

}

993

1272

}

994

1273

995

1274

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

996

1275

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

1276

if_index = (AvahiIfIndex) if_nametoindex(interface);

1277

if(if_index == 0){

1278

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

1279

exitcode = EX_UNAVAILABLE;

1280

goto end;

1281

}

1282

1283

if(quit_now){

1284

goto end;

1285

}

1286

1287

/* Re-raise priviliges */

1288

errno = 0;

1289

ret = seteuid(0);

1290

if(ret == -1){

1291

perror("seteuid");

1292

}

1293

997

1294

#ifdef __linux__

998

1295

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

999

messages to mess up the prompt */

1296

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

1000

1297

ret = klogctl(8, NULL, 5);

1001

1298

bool restore_loglevel = true;

1002

1299

if(ret == -1){

1003

1300

restore_loglevel = false;

1004

1301

perror("klogctl");

1005

1302

}

1006

#endif

1303

#endif /* __linux__ */

1007

1304

1008

1305

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1009

1306

if(sd < 0){

1010

1307

perror("socket");

1011

exitcode = EXIT_FAILURE;

1308

exitcode = EX_OSERR;

1012

1309

#ifdef __linux__

1013

1310

if(restore_loglevel){

1014

1311

ret = klogctl(7, NULL, 0);

1016

1313

perror("klogctl");

1017

1314

}

1018

1315

}

1019

#endif

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1020

1323

goto end;

1021

1324

}

1022

1325

strcpy(network.ifr_name, interface);

1030

1333

perror("klogctl");

1031

1334

}

1032

1335

}

1033

#endif

1034

exitcode = EXIT_FAILURE;

1336

#endif /* __linux__ */

1337

exitcode = EX_OSERR;

1338

/* Lower privileges */

1339

errno = 0;

1340

ret = seteuid(uid);

1341

if(ret == -1){

1342

perror("seteuid");

1343

}

1035

1344

goto end;

1036

1345

}

1037

1346

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

1038

1347

network.ifr_flags |= IFF_UP;

1348

take_down_interface = true;

1039

1349

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

1040

1350

if(ret == -1){

1351

take_down_interface = false;

1041

1352

perror("ioctl SIOCSIFFLAGS");

1042

exitcode = EXIT_FAILURE;

1353

exitcode = EX_OSERR;

1043

1354

#ifdef __linux__

1044

1355

if(restore_loglevel){

1045

1356

ret = klogctl(7, NULL, 0);

1047

1358

perror("klogctl");

1048

1359

}

1049

1360

}

1050

#endif

1361

#endif /* __linux__ */

1362

/* Lower privileges */

1363

errno = 0;

1364

ret = seteuid(uid);

1365

if(ret == -1){

1366

perror("seteuid");

1367

}

1051

1368

goto end;

1052

1369

}

1053

1370

}

1065

1382

perror("nanosleep");

1066

1383

}

1067

1384

}

1068

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

1069

if(ret == -1){

1070

perror("close");

1385

if(not take_down_interface){

1386

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

1387

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

1388

if(ret == -1){

1389

perror("close");

1390

}

1071

1391

}

1072

1392

#ifdef __linux__

1073

1393

if(restore_loglevel){

1077

1397

perror("klogctl");

1078

1398

}

1079

1399

}

1080

#endif

1081

}

1082

1083

uid = getuid();

1084

gid = getgid();

1085

1086

errno = 0;

1087

setgid(gid);

1088

if(ret == -1){

1089

perror("setgid");

1090

}

1091

1092

ret = setuid(uid);

1093

if(ret == -1){

1094

perror("setuid");

1095

}

1096

1097

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

1400

#endif /* __linux__ */

1401

/* Lower privileges */

1402

errno = 0;

1403

if(take_down_interface){

1404

/* Lower privileges */

1405

ret = seteuid(uid);

1406

if(ret == -1){

1407

perror("seteuid");

1408

}

1409

} else {

1410

/* Lower privileges permanently */

1411

ret = setuid(uid);

1412

if(ret == -1){

1413

perror("setuid");

1414

}

1415

}

1416

}

1417

1418

if(quit_now){

1419

goto end;

1420

}

1421

1422

ret = init_gnutls_global(pubkey, seckey);

1098

1423

if(ret == -1){

1099

1424

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

1100

exitcode = EXIT_FAILURE;

1425

exitcode = EX_UNAVAILABLE;

1101

1426

goto end;

1102

1427

} else {

1103

1428

gnutls_initialized = true;

1104

1429

}

1105

1430

1431

if(quit_now){

1432

goto end;

1433

}

1434

1435

tempdir_created = true;

1106

1436

if(mkdtemp(tempdir) == NULL){

1437

tempdir_created = false;

1107

1438

perror("mkdtemp");

1108

1439

goto end;

1109

1440

}

1110

tempdir_created = true;

1111

1112

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

1441

1442

if(quit_now){

1443

goto end;

1444

}

1445

1446

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

1113

1447

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

1114

exitcode = EXIT_FAILURE;

1448

exitcode = EX_UNAVAILABLE;

1115

1449

goto end;

1116

1450

} else {

1117

1451

gpgme_initialized = true;

1118

1452

}

1119

1453

1120

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

1121

if_index = (AvahiIfIndex) if_nametoindex(interface);

1122

if(if_index == 0){

1123

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

1124

exitcode = EXIT_FAILURE;

1125

goto end;

1126

}

1454

if(quit_now){

1455

goto end;

1127

1456

}

1128

1457

1129

1458

if(connect_to != NULL){

1132

1461

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

1133

1462

if(address == NULL){

1134

1463

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

1135

exitcode = EXIT_FAILURE;

1136

goto end;

1137

}

1464

exitcode = EX_USAGE;

1465

goto end;

1466

}

1467

1468

if(quit_now){

1469

goto end;

1470

}

1471

1138

1472

uint16_t port;

1139

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

1140

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

1141

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

1473

errno = 0;

1474

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

1475

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

1476

or tmpmax != (uint16_t)tmpmax){

1142

1477

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

1143

exitcode = EXIT_FAILURE;

1144

goto end;

1145

}

1478

exitcode = EX_USAGE;

1479

goto end;

1480

}

1481

1482

if(quit_now){

1483

goto end;

1484

}

1485

1146

1486

port = (uint16_t)tmpmax;

1147

1487

*address = '\0';

1148

1488

address = connect_to;

1153

1493

} else {

1154

1494

af = AF_INET;

1155

1495

}

1156

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

1157

af);

1496

1497

if(quit_now){

1498

goto end;

1499

}

1500

1501

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

1158

1502

if(ret < 0){

1159

exitcode = EXIT_FAILURE;

1503

switch(errno){

1504

case ENETUNREACH:

1505

case EHOSTDOWN:

1506

case EHOSTUNREACH:

1507

exitcode = EX_NOHOST;

1508

break;

1509

case EINVAL:

1510

exitcode = EX_USAGE;

1511

break;

1512

case EIO:

1513

exitcode = EX_IOERR;

1514

break;

1515

case EPROTO:

1516

exitcode = EX_PROTOCOL;

1517

break;

1518

default:

1519

exitcode = EX_OSERR;

1520

break;

1521

}

1160

1522

} else {

1161

1523

exitcode = EXIT_SUCCESS;

1162

1524

}

1163

1525

goto end;

1164

1526

}

1165

1527

1166

if(not debug){

1167

avahi_set_log_function(empty_log);

1168

}

1169

1170

/* Initialize the pseudo-RNG for Avahi */

1171

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

1172

1173

/* Allocate main Avahi loop object */

1174

mc.simple_poll = avahi_simple_poll_new();

1175

if(mc.simple_poll == NULL){

1176

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

1177

exitcode = EXIT_FAILURE;

1528

if(quit_now){

1178

1529

goto end;

1179

1530

}

1180

1531

1200

1551

if(mc.server == NULL){

1201

1552

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

1202

1553

avahi_strerror(error));

1203

exitcode = EXIT_FAILURE;

1554

exitcode = EX_UNAVAILABLE;

1555

goto end;

1556

}

1557

1558

if(quit_now){

1204

1559

goto end;

1205

1560

}

1206

1561

1207

1562

/* Create the Avahi service browser */

1208

1563

sb = avahi_s_service_browser_new(mc.server, if_index,

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1210

NULL, 0, browse_callback, &mc);

1564

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1565

NULL, 0, browse_callback, NULL);

1211

1566

if(sb == NULL){

1212

1567

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

1213

1568

avahi_strerror(avahi_server_errno(mc.server)));

1214

exitcode = EXIT_FAILURE;

1569

exitcode = EX_UNAVAILABLE;

1570

goto end;

1571

}

1572

1573

if(quit_now){

1215

1574

goto end;

1216

1575

}

1217

1576

1249

1608

gpgme_release(mc.ctx);

1250

1609

}

1251

1610

1611

/* Take down the network interface */

1612

if(take_down_interface){

1613

/* Re-raise priviliges */

1614

errno = 0;

1615

ret = seteuid(0);

1616

if(ret == -1){

1617

perror("seteuid");

1618

}

1619

if(geteuid() == 0){

1620

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

1621

if(ret == -1){

1622

perror("ioctl SIOCGIFFLAGS");

1623

} else if(network.ifr_flags & IFF_UP) {

1624

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

1625

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

1626

if(ret == -1){

1627

perror("ioctl SIOCSIFFLAGS");

1628

}

1629

}

1630

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

1631

if(ret == -1){

1632

perror("close");

1633

}

1634

/* Lower privileges permanently */

1635

errno = 0;

1636

ret = setuid(uid);

1637

if(ret == -1){

1638

perror("setuid");

1639

}

1640

}

1641

}

1642

1252

1643

/* Removes the temp directory used by GPGME */

1253

1644

if(tempdir_created){

1254

1645

DIR *d;

1293

1684

}

1294

1685

}

1295

1686

1687

if(quit_now){

1688

sigemptyset(&old_sigterm_action.sa_mask);

1689

old_sigterm_action.sa_handler = SIG_DFL;

1690

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1691

&old_sigterm_action,

1692

NULL));

1693

if(ret == -1){

1694

perror("sigaction");

1695

}

1696

do {

1697

ret = raise(signal_received);

1698

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

1699

if(ret != 0){

1700

perror("raise");

1701

abort();

1702

}

1703

TEMP_FAILURE_RETRY(pause());

1704

}

1705

1296

1706

return exitcode;

1297

1707

}