/mandos/release : revision 237.2.59

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

132

/*

146

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

147

* 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,

148

135

* "buffer_length" is how much is already used.

149

136

*/

150

size_t incbuffer(char **buffer, size_t buffer_length,

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

151

138

size_t buffer_capacity){

152

139

if(buffer_length + BUFFER_SIZE > buffer_capacity){

153

140

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

162

149

/*

163

150

* Initialize GPGME.

164

151

*/

165

static bool init_gpgme(const char *seckey,

152

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

166

153

const char *pubkey, const char *tempdir){

154

int ret;

167

155

gpgme_error_t rc;

168

156

gpgme_engine_info_t engine_info;

169

157

172

160

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

173

161

*/

174

162

bool import_key(const char *filename){

175

int ret;

176

163

int fd;

177

164

gpgme_data_t pgp_data;

178

165

189

176

return false;

190

177

}

191

178

192

rc = gpgme_op_import(mc.ctx, pgp_data);

179

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

193

180

if(rc != GPG_ERR_NO_ERROR){

194

181

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

195

182

gpgme_strsource(rc), gpgme_strerror(rc));

205

192

}

206

193

207

194

if(debug){

208

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

195

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

209

196

}

210

197

211

198

/* Init GPGME */

238

225

}

239

226

240

227

/* Create new GPGME "context" */

241

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

228

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

242

229

if(rc != GPG_ERR_NO_ERROR){

243

230

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

244

231

gpgme_strsource(rc), gpgme_strerror(rc));

249

236

return false;

250

237

}

251

238

252

return true;

239

return true;

253

240

}

254

241

255

242

/*

256

243

* Decrypt OpenPGP data.

257

244

* Returns -1 on error

258

245

*/

259

static ssize_t pgp_packet_decrypt(const char *cryptotext,

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

260

248

size_t crypto_size,

261

249

char **plaintext){

262

250

gpgme_data_t dh_crypto, dh_plain;

289

277

290

278

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

291

279

data buffer */

292

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

280

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

293

281

if(rc != GPG_ERR_NO_ERROR){

294

282

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

295

283

gpgme_strsource(rc), gpgme_strerror(rc));

296

284

plaintext_length = -1;

297

285

if(debug){

298

286

gpgme_decrypt_result_t result;

299

result = gpgme_op_decrypt_result(mc.ctx);

287

result = gpgme_op_decrypt_result(mc->ctx);

300

288

if(result == NULL){

301

289

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

302

290

} else {

309

297

}

310

298

gpgme_recipient_t recipient;

311

299

recipient = result->recipients;

312

while(recipient != NULL){

313

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

314

gpgme_pubkey_algo_name(recipient->pubkey_algo));

315

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

316

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

317

recipient->status == GPG_ERR_NO_SECKEY

318

? "No" : "Yes");

319

recipient = recipient->next;

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

}

320

310

}

321

311

}

322

312

}

336

326

337

327

*plaintext = NULL;

338

328

while(true){

339

plaintext_capacity = incbuffer(plaintext,

329

plaintext_capacity = adjustbuffer(plaintext,

340

330

(size_t)plaintext_length,

341

331

plaintext_capacity);

342

332

if(plaintext_capacity == 0){

343

perror("incbuffer");

333

perror("adjustbuffer");

344

334

plaintext_length = -1;

345

335

goto decrypt_end;

346

336

}

392

382

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

393

383

}

394

384

395

static int init_gnutls_global(const char *pubkeyfilename,

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

396

387

const char *seckeyfilename){

397

388

int ret;

398

389

416

407

}

417

408

418

409

/* OpenPGP credentials */

419

gnutls_certificate_allocate_credentials(&mc.cred);

410

gnutls_certificate_allocate_credentials(&mc->cred);

420

411

if(ret != GNUTLS_E_SUCCESS){

421

412

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

422

from

423

-Wunreachable-code

424

*/

413

* from

414

* -Wunreachable-code

415

*/

425

416

safer_gnutls_strerror(ret));

426

417

gnutls_global_deinit();

427

418

return -1;

434

425

}

435

426

436

427

ret = gnutls_certificate_set_openpgp_key_file

437

(mc.cred, pubkeyfilename, seckeyfilename,

428

(mc->cred, pubkeyfilename, seckeyfilename,

438

429

GNUTLS_OPENPGP_FMT_BASE64);

439

430

if(ret != GNUTLS_E_SUCCESS){

440

431

fprintf(stderr,

446

437

}

447

438

448

439

/* GnuTLS server initialization */

449

ret = gnutls_dh_params_init(&mc.dh_params);

440

ret = gnutls_dh_params_init(&mc->dh_params);

450

441

if(ret != GNUTLS_E_SUCCESS){

451

442

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

452

443

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

453

444

goto globalfail;

454

445

}

455

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

446

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

456

447

if(ret != GNUTLS_E_SUCCESS){

457

448

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

458

449

safer_gnutls_strerror(ret));

459

450

goto globalfail;

460

451

}

461

452

462

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

453

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

463

454

464

455

return 0;

465

456

466

457

globalfail:

467

458

468

gnutls_certificate_free_credentials(mc.cred);

459

gnutls_certificate_free_credentials(mc->cred);

469

460

gnutls_global_deinit();

470

gnutls_dh_params_deinit(mc.dh_params);

461

gnutls_dh_params_deinit(mc->dh_params);

471

462

return -1;

472

463

}

473

464

474

static int init_gnutls_session(gnutls_session_t *session){

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

475

467

int ret;

476

468

/* GnuTLS session creation */

477

469

ret = gnutls_init(session, GNUTLS_SERVER);

482

474

483

475

{

484

476

const char *err;

485

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

477

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

486

478

if(ret != GNUTLS_E_SUCCESS){

487

479

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

488

480

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

493

485

}

494

486

495

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

496

mc.cred);

488

mc->cred);

497

489

if(ret != GNUTLS_E_SUCCESS){

498

490

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

499

491

safer_gnutls_strerror(ret));

505

497

gnutls_certificate_server_set_request(*session,

506

498

GNUTLS_CERT_IGNORE);

507

499

508

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

509

501

510

502

return 0;

511

503

}

514

506

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

515

507

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

516

508

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

509

/* Called when a Mandos server is found */

521

510

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

522

511

AvahiIfIndex if_index,

523

int af){

524

int ret, tcp_sd = -1;

512

mandos_context *mc){

513

int ret, tcp_sd;

525

514

ssize_t sret;

526

union {

527

struct sockaddr_in in;

528

struct sockaddr_in6 in6;

529

} to;

515

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

530

516

char *buffer = NULL;

531

517

char *decrypted_buffer;

532

518

size_t buffer_length = 0;

533

519

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

534

521

size_t written;

535

522

int retval = 0;

523

char interface[IF_NAMESIZE];

536

524

gnutls_session_t session;

537

int pf; /* Protocol family */

538

539

if(quit_now){

540

return -1;

541

}

542

543

switch(af){

544

case AF_INET6:

545

pf = PF_INET6;

546

break;

547

case AF_INET:

548

pf = PF_INET;

549

break;

550

default:

551

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

552

return -1;

553

}

554

555

ret = init_gnutls_session(&session);

525

526

ret = init_gnutls_session(mc, &session);

556

527

if(ret != 0){

557

528

return -1;

558

529

}

559

530

560

531

if(debug){

561

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

532

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

562

533

"\n", ip, port);

563

534

}

564

535

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

566

537

if(tcp_sd < 0){

567

538

perror("socket");

568

retval = -1;

569

goto mandos_end;

539

return -1;

570

540

}

571

541

572

if(quit_now){

573

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);

574

548

}

575

549

576

550

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

577

if(af == AF_INET6){

578

to.in6.sin6_family = (sa_family_t)af;

579

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

580

} else { /* IPv4 */

581

to.in.sin_family = (sa_family_t)af;

582

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

583

}

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);

584

555

if(ret < 0 ){

585

556

perror("inet_pton");

586

retval = -1;

587

goto mandos_end;

557

return -1;

588

558

}

589

559

if(ret == 0){

590

560

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

591

retval = -1;

592

goto mandos_end;

561

return -1;

593

562

}

594

if(af == AF_INET6){

595

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

596

-Wconversion and

597

-Wunreachable-code */

598

599

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

600

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

601

-Wunreachable-code*/

602

if(if_index == AVAHI_IF_UNSPEC){

603

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

604

" without a network interface\n");

605

retval = -1;

606

goto mandos_end;

607

}

608

/* Set the network interface number as scope */

609

to.in6.sin6_scope_id = (uint32_t)if_index;

610

}

611

} else {

612

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

563

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

613

564

-Wconversion and

614

565

-Wunreachable-code */

615

}

616

566

617

if(quit_now){

618

goto mandos_end;

619

}

567

to.in6.sin6_scope_id = (uint32_t)if_index;

620

568

621

569

if(debug){

622

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

623

char interface[IF_NAMESIZE];

624

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

625

perror("if_indextoname");

626

} else {

627

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

628

ip, interface, port);

629

}

630

} else {

631

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

632

port);

633

}

634

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

635

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

636

const char *pcret;

637

if(af == AF_INET6){

638

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

639

sizeof(addrstr));

640

} else {

641

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

642

sizeof(addrstr));

643

}

644

if(pcret == NULL){

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){

645

575

perror("inet_ntop");

646

576

} else {

647

577

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

650

580

}

651

581

}

652

582

653

if(quit_now){

654

goto mandos_end;

655

}

656

657

if(af == AF_INET6){

658

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

659

} else {

660

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

661

}

583

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

662

584

if(ret < 0){

663

585

perror("connect");

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

586

return -1;

670

587

}

671

588

672

589

const char *out = mandos_protocol_version;

691

608

break;

692

609

}

693

610

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

698

611

}

699

612

700

613

if(debug){

701

614

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

702

615

}

703

616

704

if(quit_now){

705

goto mandos_end;

706

}

707

708

617

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

709

618

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

619

do{

715

620

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

719

621

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

720

622

721

623

if(ret != GNUTLS_E_SUCCESS){

730

632

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

731

633

732

634

if(debug){

733

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

635

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

734

636

ip);

735

637

}

736

638

737

639

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

743

buffer_capacity = incbuffer(&buffer, buffer_length,

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

744

641

buffer_capacity);

745

642

if(buffer_capacity == 0){

746

perror("incbuffer");

643

perror("adjustbuffer");

747

644

retval = -1;

748

645

goto mandos_end;

749

646

}

750

647

751

if(quit_now){

752

goto mandos_end;

753

}

754

755

648

sret = gnutls_record_recv(session, buffer+buffer_length,

756

649

BUFFER_SIZE);

757

650

if(sret == 0){

763

656

case GNUTLS_E_AGAIN:

764

657

break;

765

658

case GNUTLS_E_REHANDSHAKE:

766

do {

659

do{

767

660

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

772

661

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

773

662

if(ret < 0){

774

663

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

793

682

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

794

683

}

795

684

796

if(quit_now){

797

goto mandos_end;

798

}

799

800

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

686

802

if(quit_now){

803

goto mandos_end;

804

}

805

806

687

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

809

689

buffer_length,

810

690

&decrypted_buffer);

811

691

if(decrypted_buffer_size >= 0){

812

813

692

written = 0;

814

693

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

819

694

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

820

695

(size_t)decrypted_buffer_size - written,

821

696

stdout);

841

716

842

717

mandos_end:

843

718

free(buffer);

844

if(tcp_sd >= 0){

845

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

846

}

719

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

847

720

if(ret == -1){

848

721

perror("close");

849

722

}

850

723

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

854

724

return retval;

855

725

}

856

726

857

727

static void resolve_callback(AvahiSServiceResolver *r,

858

728

AvahiIfIndex interface,

859

AvahiProtocol proto,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

860

730

AvahiResolverEvent event,

861

731

const char *name,

862

732

const char *type,

867

737

AVAHI_GCC_UNUSED AvahiStringList *txt,

868

738

AVAHI_GCC_UNUSED AvahiLookupResultFlags

869

739

flags,

870

AVAHI_GCC_UNUSED void* userdata){

740

void* userdata){

741

mandos_context *mc = userdata;

871

742

assert(r);

872

743

873

744

/* Called whenever a service has been resolved successfully or

874

745

timed out */

875

746

876

if(quit_now){

877

return;

878

}

879

880

747

switch(event){

881

748

default:

882

749

case AVAHI_RESOLVER_FAILURE:

883

750

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

884

751

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

885

avahi_strerror(avahi_server_errno(mc.server)));

752

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

886

753

break;

887

754

888

755

case AVAHI_RESOLVER_FOUND:

894

761

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

895

762

ip, (intmax_t)interface, port);

896

763

}

897

int ret = start_mandos_communication(ip, port, interface,

898

avahi_proto_to_af(proto));

764

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

899

765

if(ret == 0){

900

avahi_simple_poll_quit(mc.simple_poll);

766

avahi_simple_poll_quit(mc->simple_poll);

901

767

}

902

768

}

903

769

}

913

779

const char *domain,

914

780

AVAHI_GCC_UNUSED AvahiLookupResultFlags

915

781

flags,

916

AVAHI_GCC_UNUSED void* userdata){

782

void* userdata){

783

mandos_context *mc = userdata;

917

784

assert(b);

918

785

919

786

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

920

787

is removed from the LAN */

921

788

922

if(quit_now){

923

return;

924

}

925

926

789

switch(event){

927

790

default:

928

791

case AVAHI_BROWSER_FAILURE:

929

792

930

793

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

931

avahi_strerror(avahi_server_errno(mc.server)));

932

avahi_simple_poll_quit(mc.simple_poll);

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

933

796

return;

934

797

935

798

case AVAHI_BROWSER_NEW:

938

801

the callback function is called the Avahi server will free the

939

802

resolver for us. */

940

803

941

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

942

name, type, domain, protocol, 0,

943

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)))

944

808

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

945

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

809

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

946

810

break;

947

811

948

812

case AVAHI_BROWSER_REMOVE:

957

821

}

958

822

}

959

823

960

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

961

static void handle_sigterm(int sig){

962

if(quit_now){

963

return;

964

}

965

quit_now = 1;

966

signal_received = sig;

967

int old_errno = errno;

968

if(mc.simple_poll != NULL){

969

avahi_simple_poll_quit(mc.simple_poll);

970

}

971

errno = old_errno;

972

}

973

974

824

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

975

825

AvahiSServiceBrowser *sb = NULL;

976

826

int error;

977

827

int ret;

978

828

intmax_t tmpmax;

979

char *tmp;

829

int numchars;

980

830

int exitcode = EXIT_SUCCESS;

981

831

const char *interface = "eth0";

982

832

struct ifreq network;

983

int sd = -1;

984

bool take_down_interface = false;

833

int sd;

985

834

uid_t uid;

986

835

gid_t gid;

987

836

char *connect_to = NULL;

991

840

const char *seckey = PATHDIR "/" SECKEY;

992

841

const char *pubkey = PATHDIR "/" PUBKEY;

993

842

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

994

846

bool gnutls_initialized = false;

995

847

bool gpgme_initialized = false;

996

float delay = 2.5f;

997

998

struct sigaction old_sigterm_action;

999

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

848

double delay = 2.5;

1000

849

1001

850

{

1002

851

struct argp_option options[] = {

1008

857

.group = 1 },

1009

858

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

1010

859

.arg = "NAME",

1011

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

1012

" Mandos servers",

860

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

861

" servers",

1013

862

.group = 1 },

1014

863

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

1015

864

.arg = "FILE",

1054

903

pubkey = arg;

1055

904

break;

1056

905

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

1057

errno = 0;

1058

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

1059

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

1060

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

906

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

907

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

908

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

1061

909

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

1062

910

exit(EXIT_FAILURE);

1063

911

}

1067

915

mc.priority = arg;

1068

916

break;

1069

917

case 131: /* --delay */

1070

errno = 0;

1071

delay = strtof(arg, &tmp);

1072

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'){

1073

920

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

1074

921

exit(EXIT_FAILURE);

1075

922

}

1096

943

}

1097

944

}

1098

945

1099

if(not debug){

1100

avahi_set_log_function(empty_log);

1101

}

1102

1103

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

1104

from the signal handler */

1105

/* Initialize the pseudo-RNG for Avahi */

1106

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

1107

mc.simple_poll = avahi_simple_poll_new();

1108

if(mc.simple_poll == NULL){

1109

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

1110

exitcode = EXIT_FAILURE;

1111

goto end;

1112

}

1113

1114

sigemptyset(&sigterm_action.sa_mask);

1115

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

1116

if(ret == -1){

1117

perror("sigaddset");

1118

exitcode = EXIT_FAILURE;

1119

goto end;

1120

}

1121

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

1122

if(ret == -1){

1123

perror("sigaddset");

1124

exitcode = EXIT_FAILURE;

1125

goto end;

1126

}

1127

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

1128

if(ret == -1){

1129

perror("sigaddset");

1130

exitcode = EXIT_FAILURE;

1131

goto end;

1132

}

1133

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

1134

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

1135

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

1136

*/

1137

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

1138

if(ret == -1){

1139

perror("sigaction");

1140

return EXIT_FAILURE;

1141

}

1142

if(old_sigterm_action.sa_handler != SIG_IGN){

1143

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

1144

if(ret == -1){

1145

perror("sigaction");

1146

exitcode = EXIT_FAILURE;

1147

goto end;

1148

}

1149

}

1150

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

1151

if(ret == -1){

1152

perror("sigaction");

1153

return EXIT_FAILURE;

1154

}

1155

if(old_sigterm_action.sa_handler != SIG_IGN){

1156

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

1157

if(ret == -1){

1158

perror("sigaction");

1159

exitcode = EXIT_FAILURE;

1160

goto end;

1161

}

1162

}

1163

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

1164

if(ret == -1){

1165

perror("sigaction");

1166

return EXIT_FAILURE;

1167

}

1168

if(old_sigterm_action.sa_handler != SIG_IGN){

1169

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

1170

if(ret == -1){

1171

perror("sigaction");

1172

exitcode = EXIT_FAILURE;

1173

goto end;

1174

}

1175

}

1176

1177

946

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

1178

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

1179

if_index = (AvahiIfIndex) if_nametoindex(interface);

1180

if(if_index == 0){

1181

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

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

1186

if(quit_now){

1187

goto end;

1188

}

1189

947

{

1190

948

#ifdef __linux__

1191

949

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1192

950

messages to mess up the prompt */

1193

951

ret = klogctl(8, NULL, 5);

1194

bool restore_loglevel = true;

1195

952

if(ret == -1){

1196

restore_loglevel = false;

1197

953

perror("klogctl");

1198

954

}

1199

#endif /* __linux__ */

955

#endif

1200

956

1201

957

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1202

958

if(sd < 0){

1203

959

perror("socket");

1204

960

exitcode = EXIT_FAILURE;

1205

961

#ifdef __linux__

1206

if(restore_loglevel){

1207

ret = klogctl(7, NULL, 0);

1208

if(ret == -1){

1209

perror("klogctl");

1210

}

962

ret = klogctl(7, NULL, 0);

963

if(ret == -1){

964

perror("klogctl");

1211

965

}

1212

#endif /* __linux__ */

966

#endif

1213

967

goto end;

1214

968

}

1215

969

strcpy(network.ifr_name, interface);

1217

971

if(ret == -1){

1218

972

perror("ioctl SIOCGIFFLAGS");

1219

973

#ifdef __linux__

1220

if(restore_loglevel){

1221

ret = klogctl(7, NULL, 0);

1222

if(ret == -1){

1223

perror("klogctl");

1224

}

974

ret = klogctl(7, NULL, 0);

975

if(ret == -1){

976

perror("klogctl");

1225

977

}

1226

#endif /* __linux__ */

978

#endif

1227

979

exitcode = EXIT_FAILURE;

1228

980

goto end;

1229

981

}

1230

982

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

1231

983

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1233

984

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

1234

985

if(ret == -1){

1235

take_down_interface = false;

1236

986

perror("ioctl SIOCSIFFLAGS");

1237

987

exitcode = EXIT_FAILURE;

1238

988

#ifdef __linux__

1239

if(restore_loglevel){

1240

ret = klogctl(7, NULL, 0);

1241

if(ret == -1){

1242

perror("klogctl");

1243

}

989

ret = klogctl(7, NULL, 0);

990

if(ret == -1){

991

perror("klogctl");

1244

992

}

1245

#endif /* __linux__ */

993

#endif

1246

994

goto end;

1247

995

}

1248

996

}

1260

1008

perror("nanosleep");

1261

1009

}

1262

1010

}

1263

if(not take_down_interface){

1264

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

1265

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

1266

if(ret == -1){

1267

perror("close");

1268

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1269

1014

}

1270

1015

#ifdef __linux__

1271

if(restore_loglevel){

1272

/* Restores kernel loglevel to default */

1273

ret = klogctl(7, NULL, 0);

1274

if(ret == -1){

1275

perror("klogctl");

1276

}

1016

/* Restores kernel loglevel to default */

1017

ret = klogctl(7, NULL, 0);

1018

if(ret == -1){

1019

perror("klogctl");

1277

1020

}

1278

#endif /* __linux__ */

1279

}

1280

1281

if(quit_now){

1282

goto end;

1021

#endif

1283

1022

}

1284

1023

1285

1024

uid = getuid();

1286

1025

gid = getgid();

1287

1026

1288

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

1289

errno = 0;

1290

ret = setgid(gid);

1027

setgid(gid);

1291

1028

if(ret == -1){

1292

1029

perror("setgid");

1293

1030

}

1294

1031

1295

/* Drop user privileges */

1296

errno = 0;

1297

/* Will we need privileges later? */

1298

if(take_down_interface){

1299

/* Drop user privileges temporarily */

1300

ret = seteuid(uid);

1301

if(ret == -1){

1302

perror("seteuid");

1303

}

1304

} else {

1305

/* Drop user privileges permanently */

1306

ret = setuid(uid);

1307

if(ret == -1){

1308

perror("setuid");

1309

}

1310

}

1311

1312

if(quit_now){

1313

goto end;

1314

}

1315

1316

ret = init_gnutls_global(pubkey, seckey);

1032

ret = setuid(uid);

1033

if(ret == -1){

1034

perror("setuid");

1035

}

1036

1037

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

1317

1038

if(ret == -1){

1318

1039

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

1319

1040

exitcode = EXIT_FAILURE;

1322

1043

gnutls_initialized = true;

1323

1044

}

1324

1045

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1330

1046

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1332

1047

perror("mkdtemp");

1333

1048

goto end;

1334

1049

}

1335

1336

if(quit_now){

1337

goto end;

1338

}

1339

1340

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

1050

tempdir_created = true;

1051

1052

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

1341

1053

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

1342

1054

exitcode = EXIT_FAILURE;

1343

1055

goto end;

1345

1057

gpgme_initialized = true;

1346

1058

}

1347

1059

1348

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;

1349

1064

goto end;

1350

1065

}

1351

1066

1358

1073

exitcode = EXIT_FAILURE;

1359

1074

goto end;

1360

1075

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1366

1076

uint16_t port;

1367

errno = 0;

1368

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

1369

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

1370

or tmpmax != (uint16_t)tmpmax){

1077

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

1078

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

1079

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

1371

1080

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

1372

1081

exitcode = EXIT_FAILURE;

1373

1082

goto end;

1374

1083

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1380

1084

port = (uint16_t)tmpmax;

1381

1085

*address = '\0';

1382

1086

address = connect_to;

1383

/* Colon in address indicates IPv6 */

1384

int af;

1385

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

1386

af = AF_INET6;

1387

} else {

1388

af = AF_INET;

1389

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1395

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

1087

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

1396

1088

if(ret < 0){

1397

1089

exitcode = EXIT_FAILURE;

1398

1090

} else {

1401

1093

goto end;

1402

1094

}

1403

1095

1404

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;

1405

1108

goto end;

1406

1109

}

1407

1110

1431

1134

goto end;

1432

1135

}

1433

1136

1434

if(quit_now){

1435

goto end;

1436

}

1437

1438

1137

/* Create the Avahi service browser */

1439

1138

sb = avahi_s_service_browser_new(mc.server, if_index,

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1441

NULL, 0, browse_callback, NULL);

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1442

1141

if(sb == NULL){

1443

1142

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

1444

1143

avahi_strerror(avahi_server_errno(mc.server)));

1446

1145

goto end;

1447

1146

}

1448

1147

1449

if(quit_now){

1450

goto end;

1451

}

1452

1453

1148

/* Run the main loop */

1454

1149

1455

1150

if(debug){

1484

1179

gpgme_release(mc.ctx);

1485

1180

}

1486

1181

1487

/* Take down the network interface */

1488

if(take_down_interface){

1489

/* Re-raise priviliges */

1490

errno = 0;

1491

ret = seteuid(0);

1492

if(ret == -1){

1493

perror("seteuid");

1494

}

1495

if(geteuid() == 0){

1496

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

1497

if(ret == -1){

1498

perror("ioctl SIOCGIFFLAGS");

1499

} else if(network.ifr_flags & IFF_UP) {

1500

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

1501

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

1502

if(ret == -1){

1503

perror("ioctl SIOCSIFFLAGS");

1504

}

1505

}

1506

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

1507

if(ret == -1){

1508

perror("close");

1509

}

1510

/* Lower privileges, permanently this time */

1511

errno = 0;

1512

ret = setuid(uid);

1513

if(ret == -1){

1514

perror("setuid");

1515

}

1516

}

1517

}

1518

1519

1182

/* Removes the temp directory used by GPGME */

1520

1183

if(tempdir_created){

1521

1184

DIR *d;

1560

1223

}

1561

1224

}

1562

1225

1563

if(quit_now){

1564

sigemptyset(&old_sigterm_action.sa_mask);

1565

old_sigterm_action.sa_handler = SIG_DFL;

1566

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

1567

if(ret == -1){

1568

perror("sigaction");

1569

}

1570

raise(signal_received);

1571

}

1572

1573

1226

return exitcode;

1574

1227

}