/mandos/release : revision 237.2.158

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() */

47

srand(), 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 */

86

78

87

#ifdef __linux__

79

88

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

80

#endif

89

#endif /* __linux__ */

81

90

82

91

/* Avahi */

83

92

/* All Avahi types, constants and functions

129

138

gpgme_ctx_t ctx;

130

139

} mandos_context;

131

140

141

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

142

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

143

.dh_bits = 1024, .priority = "SECURE256"

144

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

145

146

sig_atomic_t quit_now = 0;

147

int signal_received = 0;

148

132

149

/*

133

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

134

* "buffer_capacity" is how much is currently allocated,

150

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

151

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

135

152

* "buffer_length" is how much is already used.

136

153

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

154

size_t incbuffer(char **buffer, size_t buffer_length,

138

155

size_t buffer_capacity){

139

156

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

157

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

149

166

/*

150

167

* Initialize GPGME.

151

168

*/

152

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

169

static bool init_gpgme(const char *seckey,

153

170

const char *pubkey, const char *tempdir){

154

int ret;

155

171

gpgme_error_t rc;

156

172

gpgme_engine_info_t engine_info;

157

173

160

176

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

161

177

*/

162

178

bool import_key(const char *filename){

179

int ret;

163

180

int fd;

164

181

gpgme_data_t pgp_data;

165

182

176

193

return false;

177

194

}

178

195

179

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

196

rc = gpgme_op_import(mc.ctx, pgp_data);

180

197

if(rc != GPG_ERR_NO_ERROR){

181

198

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

182

199

gpgme_strsource(rc), gpgme_strerror(rc));

192

209

}

193

210

194

211

if(debug){

195

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

212

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

196

213

}

197

214

198

215

/* Init GPGME */

225

242

}

226

243

227

244

/* Create new GPGME "context" */

228

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

245

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

229

246

if(rc != GPG_ERR_NO_ERROR){

230

247

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

231

248

gpgme_strsource(rc), gpgme_strerror(rc));

236

253

return false;

237

254

}

238

255

239

return true;

256

return true;

240

257

}

241

258

242

259

/*

243

260

* Decrypt OpenPGP data.

244

261

* Returns -1 on error

245

262

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

263

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

264

size_t crypto_size,

249

265

char **plaintext){

250

266

gpgme_data_t dh_crypto, dh_plain;

277

293

278

294

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

279

295

data buffer */

280

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

296

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

281

297

if(rc != GPG_ERR_NO_ERROR){

282

298

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

283

299

gpgme_strsource(rc), gpgme_strerror(rc));

284

300

plaintext_length = -1;

285

301

if(debug){

286

302

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

303

result = gpgme_op_decrypt_result(mc.ctx);

288

304

if(result == NULL){

289

305

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

290

306

} else {

297

313

}

298

314

gpgme_recipient_t recipient;

299

315

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

}

316

while(recipient != NULL){

317

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

318

gpgme_pubkey_algo_name(recipient->pubkey_algo));

319

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

320

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

321

recipient->status == GPG_ERR_NO_SECKEY

322

? "No" : "Yes");

323

recipient = recipient->next;

310

324

}

311

325

}

312

326

}

326

340

327

341

*plaintext = NULL;

328

342

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

343

plaintext_capacity = incbuffer(plaintext,

330

344

(size_t)plaintext_length,

331

345

plaintext_capacity);

332

346

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

347

perror("incbuffer");

334

348

plaintext_length = -1;

335

349

goto decrypt_end;

336

350

}

382

396

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

383

397

}

384

398

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

399

static int init_gnutls_global(const char *pubkeyfilename,

387

400

const char *seckeyfilename){

388

401

int ret;

389

402

407

420

}

408

421

409

422

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

423

gnutls_certificate_allocate_credentials(&mc.cred);

411

424

if(ret != GNUTLS_E_SUCCESS){

412

425

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

413

426

from

425

438

}

426

439

427

440

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

441

(mc.cred, pubkeyfilename, seckeyfilename,

429

442

GNUTLS_OPENPGP_FMT_BASE64);

430

443

if(ret != GNUTLS_E_SUCCESS){

431

444

fprintf(stderr,

437

450

}

438

451

439

452

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

453

ret = gnutls_dh_params_init(&mc.dh_params);

441

454

if(ret != GNUTLS_E_SUCCESS){

442

455

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

443

456

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

444

457

goto globalfail;

445

458

}

446

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

459

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

447

460

if(ret != GNUTLS_E_SUCCESS){

448

461

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

449

462

safer_gnutls_strerror(ret));

450

463

goto globalfail;

451

464

}

452

465

453

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

466

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

467

455

468

return 0;

456

469

457

470

globalfail:

458

471

459

gnutls_certificate_free_credentials(mc->cred);

472

gnutls_certificate_free_credentials(mc.cred);

460

473

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

474

gnutls_dh_params_deinit(mc.dh_params);

462

475

return -1;

463

476

}

464

477

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

478

static int init_gnutls_session(gnutls_session_t *session){

467

479

int ret;

468

480

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

481

do {

482

ret = gnutls_init(session, GNUTLS_SERVER);

483

if(quit_now){

484

return -1;

485

}

486

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

470

487

if(ret != GNUTLS_E_SUCCESS){

471

488

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

472

489

safer_gnutls_strerror(ret));

474

491

475

492

{

476

493

const char *err;

477

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

494

do {

495

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

496

if(quit_now){

497

gnutls_deinit(*session);

498

return -1;

499

}

500

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

478

501

if(ret != GNUTLS_E_SUCCESS){

479

502

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

480

503

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

484

507

}

485

508

}

486

509

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

510

do {

511

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

512

mc.cred);

513

if(quit_now){

514

gnutls_deinit(*session);

515

return -1;

516

}

517

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

489

518

if(ret != GNUTLS_E_SUCCESS){

490

519

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

491

520

safer_gnutls_strerror(ret));

494

523

}

495

524

496

525

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

526

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

527

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

528

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

529

502

530

return 0;

503

531

}

509

537

/* Called when a Mandos server is found */

510

538

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

511

539

AvahiIfIndex if_index,

512

mandos_context *mc, int af){

513

int ret, tcp_sd;

540

int af){

541

int ret, tcp_sd = -1;

514

542

ssize_t sret;

515

543

union {

516

544

struct sockaddr_in in;

517

545

struct sockaddr_in6 in6;

518

546

} to;

519

547

char *buffer = NULL;

520

char *decrypted_buffer;

548

char *decrypted_buffer = NULL;

521

549

size_t buffer_length = 0;

522

550

size_t buffer_capacity = 0;

523

ssize_t decrypted_buffer_size;

524

551

size_t written;

525

int retval = 0;

552

int retval = -1;

526

553

gnutls_session_t session;

527

554

int pf; /* Protocol family */

528

555

556

if(quit_now){

557

return -1;

558

}

559

529

560

switch(af){

530

561

case AF_INET6:

531

562

pf = PF_INET6;

538

569

return -1;

539

570

}

540

571

541

ret = init_gnutls_session(mc, &session);

572

ret = init_gnutls_session(&session);

542

573

if(ret != 0){

543

574

return -1;

544

575

}

551

582

tcp_sd = socket(pf, SOCK_STREAM, 0);

552

583

if(tcp_sd < 0){

553

584

perror("socket");

554

return -1;

585

goto mandos_end;

586

}

587

588

if(quit_now){

589

goto mandos_end;

555

590

}

556

591

557

592

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

558

593

if(af == AF_INET6){

559

to.in6.sin6_family = (uint16_t)af;

594

to.in6.sin6_family = (sa_family_t)af;

560

595

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

561

596

} else { /* IPv4 */

562

597

to.in.sin_family = (sa_family_t)af;

564

599

}

565

600

if(ret < 0 ){

566

601

perror("inet_pton");

567

return -1;

602

goto mandos_end;

568

603

}

569

604

if(ret == 0){

570

605

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

571

return -1;

606

goto mandos_end;

572

607

}

573

608

if(af == AF_INET6){

574

609

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

581

616

if(if_index == AVAHI_IF_UNSPEC){

582

617

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

583

618

" without a network interface\n");

584

return -1;

619

goto mandos_end;

585

620

}

586

621

/* Set the network interface number as scope */

587

622

to.in6.sin6_scope_id = (uint32_t)if_index;

592

627

-Wunreachable-code */

593

628

}

594

629

630

if(quit_now){

631

goto mandos_end;

632

}

633

595

634

if(debug){

596

635

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

597

636

char interface[IF_NAMESIZE];

624

663

}

625

664

}

626

665

666

if(quit_now){

667

goto mandos_end;

668

}

669

627

670

if(af == AF_INET6){

628

671

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

629

672

} else {

631

674

}

632

675

if(ret < 0){

633

676

perror("connect");

634

return -1;

677

goto mandos_end;

678

}

679

680

if(quit_now){

681

goto mandos_end;

635

682

}

636

683

637

684

const char *out = mandos_protocol_version;

642

689

out_size - written));

643

690

if(ret == -1){

644

691

perror("write");

645

retval = -1;

646

692

goto mandos_end;

647

693

}

648

694

written += (size_t)ret;

656

702

break;

657

703

}

658

704

}

705

706

if(quit_now){

707

goto mandos_end;

708

}

659

709

}

660

710

661

711

if(debug){

662

712

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

663

713

}

664

714

715

if(quit_now){

716

goto mandos_end;

717

}

718

665

719

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

666

720

667

do{

721

if(quit_now){

722

goto mandos_end;

723

}

724

725

do {

668

726

ret = gnutls_handshake(session);

727

if(quit_now){

728

goto mandos_end;

729

}

669

730

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

670

731

671

732

if(ret != GNUTLS_E_SUCCESS){

673

734

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

674

735

gnutls_perror(ret);

675

736

}

676

retval = -1;

677

737

goto mandos_end;

678

738

}

679

739

685

745

}

686

746

687

747

while(true){

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

748

749

if(quit_now){

750

goto mandos_end;

751

}

752

753

buffer_capacity = incbuffer(&buffer, buffer_length,

689

754

buffer_capacity);

690

755

if(buffer_capacity == 0){

691

perror("adjustbuffer");

692

retval = -1;

756

perror("incbuffer");

757

goto mandos_end;

758

}

759

760

if(quit_now){

693

761

goto mandos_end;

694

762

}

695

763

704

772

case GNUTLS_E_AGAIN:

705

773

break;

706

774

case GNUTLS_E_REHANDSHAKE:

707

do{

775

do {

708

776

ret = gnutls_handshake(session);

777

778

if(quit_now){

779

goto mandos_end;

780

}

709

781

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

710

782

if(ret < 0){

711

783

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

712

784

gnutls_perror(ret);

713

retval = -1;

714

785

goto mandos_end;

715

786

}

716

787

break;

717

788

default:

718

789

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

719

790

" encrypted session with Mandos server\n");

720

retval = -1;

721

791

gnutls_bye(session, GNUTLS_SHUT_RDWR);

722

792

goto mandos_end;

723

793

}

730

800

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

731

801

}

732

802

733

gnutls_bye(session, GNUTLS_SHUT_RDWR);

803

if(quit_now){

804

goto mandos_end;

805

}

806

807

do {

808

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

809

if(quit_now){

810

goto mandos_end;

811

}

812

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

734

813

735

814

if(buffer_length > 0){

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

815

ssize_t decrypted_buffer_size;

816

decrypted_buffer_size = pgp_packet_decrypt(buffer,

737

817

buffer_length,

738

818

&decrypted_buffer);

739

819

if(decrypted_buffer_size >= 0){

820

740

821

written = 0;

741

822

while(written < (size_t) decrypted_buffer_size){

823

if(quit_now){

824

goto mandos_end;

825

}

826

742

827

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

743

828

(size_t)decrypted_buffer_size - written,

744

829

stdout);

747

832

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

748

833

strerror(errno));

749

834

}

750

retval = -1;

751

break;

835

goto mandos_end;

752

836

}

753

837

written += (size_t)ret;

754

838

}

755

free(decrypted_buffer);

756

} else {

757

retval = -1;

839

retval = 0;

758

840

}

759

} else {

760

retval = -1;

761

841

}

762

842

763

843

/* Shutdown procedure */

764

844

765

845

mandos_end:

846

free(decrypted_buffer);

766

847

free(buffer);

767

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

848

if(tcp_sd >= 0){

849

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

850

}

768

851

if(ret == -1){

769

852

perror("close");

770

853

}

771

854

gnutls_deinit(session);

855

if(quit_now){

856

retval = -1;

857

}

772

858

return retval;

773

859

}

774

860

785

871

AVAHI_GCC_UNUSED AvahiStringList *txt,

786

872

AVAHI_GCC_UNUSED AvahiLookupResultFlags

787

873

flags,

788

void* userdata){

789

mandos_context *mc = userdata;

874

AVAHI_GCC_UNUSED void* userdata){

790

875

assert(r);

791

876

792

877

/* Called whenever a service has been resolved successfully or

793

878

timed out */

794

879

880

if(quit_now){

881

return;

882

}

883

795

884

switch(event){

796

885

default:

797

886

case AVAHI_RESOLVER_FAILURE:

798

887

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

799

888

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

800

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

889

avahi_strerror(avahi_server_errno(mc.server)));

801

890

break;

802

891

803

892

case AVAHI_RESOLVER_FOUND:

809

898

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

810

899

ip, (intmax_t)interface, port);

811

900

}

812

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

901

int ret = start_mandos_communication(ip, port, interface,

813

902

avahi_proto_to_af(proto));

814

903

if(ret == 0){

815

avahi_simple_poll_quit(mc->simple_poll);

904

avahi_simple_poll_quit(mc.simple_poll);

816

905

}

817

906

}

818

907

}

828

917

const char *domain,

829

918

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

919

flags,

831

void* userdata){

832

mandos_context *mc = userdata;

920

AVAHI_GCC_UNUSED void* userdata){

833

921

assert(b);

834

922

835

923

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

836

924

is removed from the LAN */

837

925

926

if(quit_now){

927

return;

928

}

929

838

930

switch(event){

839

931

default:

840

932

case AVAHI_BROWSER_FAILURE:

841

933

842

934

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

843

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

844

avahi_simple_poll_quit(mc->simple_poll);

935

avahi_strerror(avahi_server_errno(mc.server)));

936

avahi_simple_poll_quit(mc.simple_poll);

845

937

return;

846

938

847

939

case AVAHI_BROWSER_NEW:

850

942

the callback function is called the Avahi server will free the

851

943

resolver for us. */

852

944

853

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

854

protocol, name, type, domain,

855

AVAHI_PROTO_INET6, 0,

856

resolve_callback, mc)))

945

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

946

name, type, domain, protocol, 0,

947

resolve_callback, NULL) == NULL)

857

948

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

858

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

949

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

859

950

break;

860

951

861

952

case AVAHI_BROWSER_REMOVE:

870

961

}

871

962

}

872

963

964

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

965

static void handle_sigterm(int sig){

966

if(quit_now){

967

return;

968

}

969

quit_now = 1;

970

signal_received = sig;

971

int old_errno = errno;

972

if(mc.simple_poll != NULL){

973

avahi_simple_poll_quit(mc.simple_poll);

974

}

975

errno = old_errno;

976

}

977

873

978

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

874

979

AvahiSServiceBrowser *sb = NULL;

875

980

int error;

876

981

int ret;

877

982

intmax_t tmpmax;

878

int numchars;

983

char *tmp;

879

984

int exitcode = EXIT_SUCCESS;

880

985

const char *interface = "eth0";

881

986

struct ifreq network;

882

int sd;

987

int sd = -1;

988

bool take_down_interface = false;

883

989

uid_t uid;

884

990

gid_t gid;

885

991

char *connect_to = NULL;

889

995

const char *seckey = PATHDIR "/" SECKEY;

890

996

const char *pubkey = PATHDIR "/" PUBKEY;

891

997

892

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

893

.dh_bits = 1024, .priority = "SECURE256"

894

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

895

998

bool gnutls_initialized = false;

896

999

bool gpgme_initialized = false;

897

double delay = 2.5;

1000

float delay = 2.5f;

1001

1002

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1003

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1004

1005

uid = getuid();

1006

gid = getgid();

1007

1008

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

1009

errno = 0;

1010

ret = setgid(gid);

1011

if(ret == -1){

1012

perror("setgid");

1013

}

1014

1015

/* Lower user privileges (temporarily) */

1016

errno = 0;

1017

ret = seteuid(uid);

1018

if(ret == -1){

1019

perror("seteuid");

1020

}

1021

1022

if(quit_now){

1023

goto end;

1024

}

898

1025

899

1026

{

900

1027

struct argp_option options[] = {

930

1057

.arg = "SECONDS",

931

1058

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

932

1059

.group = 2 },

1060

/*

1061

* These reproduce what we would get without ARGP_NO_HELP

1062

*/

1063

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

1064

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

1065

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

1066

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

1067

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

1068

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

933

1069

{ .name = NULL }

934

1070

};

935

1071

936

1072

error_t parse_opt(int key, char *arg,

937

1073

struct argp_state *state){

1074

errno = 0;

938

1075

switch(key){

939

1076

case 128: /* --debug */

940

1077

debug = true;

952

1089

pubkey = arg;

953

1090

break;

954

1091

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);

1092

errno = 0;

1093

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

1094

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

1095

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

1096

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

960

1097

}

961

1098

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

962

1099

break;

964

1101

mc.priority = arg;

965

1102

break;

966

1103

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);

1104

errno = 0;

1105

delay = strtof(arg, &tmp);

1106

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

1107

argp_error(state, "Bad delay");

971

1108

}

972

1109

break;

973

case ARGP_KEY_ARG:

974

argp_usage(state);

975

case ARGP_KEY_END:

1110

/*

1111

* These reproduce what we would get without ARGP_NO_HELP

1112

*/

1113

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

1114

argp_state_help(state, state->out_stream,

1115

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1116

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1117

case -3: /* --usage */

1118

argp_state_help(state, state->out_stream,

1119

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1120

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

1121

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

1122

exit(argp_err_exit_status);

976

1123

break;

977

1124

default:

978

1125

return ARGP_ERR_UNKNOWN;

979

1126

}

980

return 0;

1127

return errno;

981

1128

}

982

1129

983

1130

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

984

1131

.args_doc = "",

985

1132

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

986

1133

" 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");

1134

ret = argp_parse(&argp, argc, argv,

1135

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1136

switch(ret){

1137

case 0:

1138

break;

1139

case ENOMEM:

1140

default:

1141

errno = ret;

1142

perror("argp_parse");

1143

exitcode = EX_OSERR;

1144

goto end;

1145

case EINVAL:

1146

exitcode = EX_USAGE;

1147

goto end;

1148

}

1149

}

1150

1151

if(not debug){

1152

avahi_set_log_function(empty_log);

1153

}

1154

1155

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

1156

from the signal handler */

1157

/* Initialize the pseudo-RNG for Avahi */

1158

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

1159

mc.simple_poll = avahi_simple_poll_new();

1160

if(mc.simple_poll == NULL){

1161

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

1162

exitcode = EXIT_FAILURE;

1163

goto end;

1164

}

1165

1166

sigemptyset(&sigterm_action.sa_mask);

1167

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

1168

if(ret == -1){

1169

perror("sigaddset");

1170

exitcode = EXIT_FAILURE;

1171

goto end;

1172

}

1173

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

1174

if(ret == -1){

1175

perror("sigaddset");

1176

exitcode = EXIT_FAILURE;

1177

goto end;

1178

}

1179

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

1180

if(ret == -1){

1181

perror("sigaddset");

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

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

1186

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

1187

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

1188

*/

1189

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

1190

if(ret == -1){

1191

perror("sigaction");

1192

return EXIT_FAILURE;

1193

}

1194

if(old_sigterm_action.sa_handler != SIG_IGN){

1195

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

1196

if(ret == -1){

1197

perror("sigaction");

1198

exitcode = EXIT_FAILURE;

1199

goto end;

1200

}

1201

}

1202

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

1203

if(ret == -1){

1204

perror("sigaction");

1205

return EXIT_FAILURE;

1206

}

1207

if(old_sigterm_action.sa_handler != SIG_IGN){

1208

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

1209

if(ret == -1){

1210

perror("sigaction");

1211

exitcode = EXIT_FAILURE;

1212

goto end;

1213

}

1214

}

1215

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

1216

if(ret == -1){

1217

perror("sigaction");

1218

return EXIT_FAILURE;

1219

}

1220

if(old_sigterm_action.sa_handler != SIG_IGN){

1221

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

1222

if(ret == -1){

1223

perror("sigaction");

990

1224

exitcode = EXIT_FAILURE;

991

1225

goto end;

992

1226

}

994

1228

995

1229

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

996

1230

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

1231

if_index = (AvahiIfIndex) if_nametoindex(interface);

1232

if(if_index == 0){

1233

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

1234

exitcode = EXIT_FAILURE;

1235

goto end;

1236

}

1237

1238

if(quit_now){

1239

goto end;

1240

}

1241

1242

/* Re-raise priviliges */

1243

errno = 0;

1244

ret = seteuid(0);

1245

if(ret == -1){

1246

perror("seteuid");

1247

}

1248

997

1249

#ifdef __linux__

998

1250

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

999

messages to mess up the prompt */

1251

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

1000

1252

ret = klogctl(8, NULL, 5);

1001

1253

bool restore_loglevel = true;

1002

1254

if(ret == -1){

1003

1255

restore_loglevel = false;

1004

1256

perror("klogctl");

1005

1257

}

1006

#endif

1258

#endif /* __linux__ */

1007

1259

1008

1260

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1009

1261

if(sd < 0){

1016

1268

perror("klogctl");

1017

1269

}

1018

1270

}

1019

#endif

1271

#endif /* __linux__ */

1272

/* Lower privileges */

1273

errno = 0;

1274

ret = seteuid(uid);

1275

if(ret == -1){

1276

perror("seteuid");

1277

}

1020

1278

goto end;

1021

1279

}

1022

1280

strcpy(network.ifr_name, interface);

1030

1288

perror("klogctl");

1031

1289

}

1032

1290

}

1033

#endif

1291

#endif /* __linux__ */

1034

1292

exitcode = EXIT_FAILURE;

1293

/* Lower privileges */

1294

errno = 0;

1295

ret = seteuid(uid);

1296

if(ret == -1){

1297

perror("seteuid");

1298

}

1035

1299

goto end;

1036

1300

}

1037

1301

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

1038

1302

network.ifr_flags |= IFF_UP;

1303

take_down_interface = true;

1039

1304

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

1040

1305

if(ret == -1){

1306

take_down_interface = false;

1041

1307

perror("ioctl SIOCSIFFLAGS");

1042

1308

exitcode = EXIT_FAILURE;

1043

1309

#ifdef __linux__

1047

1313

perror("klogctl");

1048

1314

}

1049

1315

}

1050

#endif

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1051

1323

goto end;

1052

1324

}

1053

1325

}

1065

1337

perror("nanosleep");

1066

1338

}

1067

1339

}

1068

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

1069

if(ret == -1){

1070

perror("close");

1340

if(not take_down_interface){

1341

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

1342

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

1343

if(ret == -1){

1344

perror("close");

1345

}

1071

1346

}

1072

1347

#ifdef __linux__

1073

1348

if(restore_loglevel){

1077

1352

perror("klogctl");

1078

1353

}

1079

1354

}

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);

1355

#endif /* __linux__ */

1356

/* Lower privileges */

1357

errno = 0;

1358

if(take_down_interface){

1359

/* Lower privileges */

1360

ret = seteuid(uid);

1361

if(ret == -1){

1362

perror("seteuid");

1363

}

1364

} else {

1365

/* Lower privileges permanently */

1366

ret = setuid(uid);

1367

if(ret == -1){

1368

perror("setuid");

1369

}

1370

}

1371

}

1372

1373

if(quit_now){

1374

goto end;

1375

}

1376

1377

ret = init_gnutls_global(pubkey, seckey);

1098

1378

if(ret == -1){

1099

1379

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

1100

1380

exitcode = EXIT_FAILURE;

1103

1383

gnutls_initialized = true;

1104

1384

}

1105

1385

1386

if(quit_now){

1387

goto end;

1388

}

1389

1390

tempdir_created = true;

1106

1391

if(mkdtemp(tempdir) == NULL){

1392

tempdir_created = false;

1107

1393

perror("mkdtemp");

1108

1394

goto end;

1109

1395

}

1110

tempdir_created = true;

1111

1112

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

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1401

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

1113

1402

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

1114

1403

exitcode = EXIT_FAILURE;

1115

1404

goto end;

1117

1406

gpgme_initialized = true;

1118

1407

}

1119

1408

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

}

1409

if(quit_now){

1410

goto end;

1127

1411

}

1128

1412

1129

1413

if(connect_to != NULL){

1135

1419

exitcode = EXIT_FAILURE;

1136

1420

goto end;

1137

1421

}

1422

1423

if(quit_now){

1424

goto end;

1425

}

1426

1138

1427

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'){

1428

errno = 0;

1429

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

1430

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

1431

or tmpmax != (uint16_t)tmpmax){

1142

1432

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

1143

1433

exitcode = EXIT_FAILURE;

1144

1434

goto end;

1145

1435

}

1436

1437

if(quit_now){

1438

goto end;

1439

}

1440

1146

1441

port = (uint16_t)tmpmax;

1147

1442

*address = '\0';

1148

1443

address = connect_to;

1153

1448

} else {

1154

1449

af = AF_INET;

1155

1450

}

1156

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

1157

af);

1451

1452

if(quit_now){

1453

goto end;

1454

}

1455

1456

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

1158

1457

if(ret < 0){

1159

1458

exitcode = EXIT_FAILURE;

1160

1459

} else {

1163

1462

goto end;

1164

1463

}

1165

1464

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;

1465

if(quit_now){

1178

1466

goto end;

1179

1467

}

1180

1468

1204

1492

goto end;

1205

1493

}

1206

1494

1495

if(quit_now){

1496

goto end;

1497

}

1498

1207

1499

/* Create the Avahi service browser */

1208

1500

sb = avahi_s_service_browser_new(mc.server, if_index,

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1210

NULL, 0, browse_callback, &mc);

1501

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1502

NULL, 0, browse_callback, NULL);

1211

1503

if(sb == NULL){

1212

1504

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

1213

1505

avahi_strerror(avahi_server_errno(mc.server)));

1215

1507

goto end;

1216

1508

}

1217

1509

1510

if(quit_now){

1511

goto end;

1512

}

1513

1218

1514

/* Run the main loop */

1219

1515

1220

1516

if(debug){

1249

1545

gpgme_release(mc.ctx);

1250

1546

}

1251

1547

1548

/* Take down the network interface */

1549

if(take_down_interface){

1550

/* Re-raise priviliges */

1551

errno = 0;

1552

ret = seteuid(0);

1553

if(ret == -1){

1554

perror("seteuid");

1555

}

1556

if(geteuid() == 0){

1557

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

1558

if(ret == -1){

1559

perror("ioctl SIOCGIFFLAGS");

1560

} else if(network.ifr_flags & IFF_UP) {

1561

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

1562

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

1563

if(ret == -1){

1564

perror("ioctl SIOCSIFFLAGS");

1565

}

1566

}

1567

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

1568

if(ret == -1){

1569

perror("close");

1570

}

1571

/* Lower privileges permanently */

1572

errno = 0;

1573

ret = setuid(uid);

1574

if(ret == -1){

1575

perror("setuid");

1576

}

1577

}

1578

}

1579

1252

1580

/* Removes the temp directory used by GPGME */

1253

1581

if(tempdir_created){

1254

1582

DIR *d;

1293

1621

}

1294

1622

}

1295

1623

1624

if(quit_now){

1625

sigemptyset(&old_sigterm_action.sa_mask);

1626

old_sigterm_action.sa_handler = SIG_DFL;

1627

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1628

&old_sigterm_action,

1629

NULL));

1630

if(ret == -1){

1631

perror("sigaction");

1632

}

1633

do {

1634

ret = raise(signal_received);

1635

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

1636

if(ret != 0){

1637

perror("raise");

1638

abort();

1639

}

1640

TEMP_FAILURE_RETRY(pause());

1641

}

1642

1296

1643

return exitcode;

1297

1644

}