/mandos/trunk : revision 302

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

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

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

47

strtof(), abort() */

48

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

43

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

44

srand() */

45

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

49

46

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

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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,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

51

SOCK_STREAM, INET6_ADDRSTRLEN,

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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,

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inet_pton(), connect() */

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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

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

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,

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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(),

75

setgid(), pause() */

76

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

77

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

70

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

71

setgid() */

72

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

73

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

78

74

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

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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

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

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

87

88

78

#ifdef __linux__

89

79

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

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#endif /* __linux__ */

80

#endif

91

81

92

82

/* Avahi */

93

83

/* All Avahi types, constants and functions

127

117

static const char mandos_protocol_version[] = "1";

128

118

const char *argp_program_version = "mandos-client " VERSION;

129

119

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

130

static const char sys_class_net[] = "/sys/class/net";

131

char *connect_to = NULL;

132

120

133

121

/* Used for passing in values through the Avahi callback functions */

134

122

typedef struct {

141

129

gpgme_ctx_t ctx;

142

130

} mandos_context;

143

131

144

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

145

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

146

.dh_bits = 1024, .priority = "SECURE256"

147

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

148

149

sig_atomic_t quit_now = 0;

150

int signal_received = 0;

151

152

132

/*

153

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

154

* 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,

155

135

* "buffer_length" is how much is already used.

156

136

*/

157

size_t incbuffer(char **buffer, size_t buffer_length,

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

158

138

size_t buffer_capacity){

159

139

if(buffer_length + BUFFER_SIZE > buffer_capacity){

160

140

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

169

149

/*

170

150

* Initialize GPGME.

171

151

*/

172

static bool init_gpgme(const char *seckey,

152

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

173

153

const char *pubkey, const char *tempdir){

154

int ret;

174

155

gpgme_error_t rc;

175

156

gpgme_engine_info_t engine_info;

176

157

179

160

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

180

161

*/

181

162

bool import_key(const char *filename){

182

int ret;

183

163

int fd;

184

164

gpgme_data_t pgp_data;

185

165

196

176

return false;

197

177

}

198

178

199

rc = gpgme_op_import(mc.ctx, pgp_data);

179

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

200

180

if(rc != GPG_ERR_NO_ERROR){

201

181

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

202

182

gpgme_strsource(rc), gpgme_strerror(rc));

212

192

}

213

193

214

194

if(debug){

215

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

195

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

216

196

}

217

197

218

198

/* Init GPGME */

245

225

}

246

226

247

227

/* Create new GPGME "context" */

248

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

228

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

249

229

if(rc != GPG_ERR_NO_ERROR){

250

230

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

251

231

gpgme_strsource(rc), gpgme_strerror(rc));

256

236

return false;

257

237

}

258

238

259

return true;

239

return true;

260

240

}

261

241

262

242

/*

263

243

* Decrypt OpenPGP data.

264

244

* Returns -1 on error

265

245

*/

266

static ssize_t pgp_packet_decrypt(const char *cryptotext,

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

267

248

size_t crypto_size,

268

249

char **plaintext){

269

250

gpgme_data_t dh_crypto, dh_plain;

296

277

297

278

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

298

279

data buffer */

299

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

280

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

300

281

if(rc != GPG_ERR_NO_ERROR){

301

282

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

302

283

gpgme_strsource(rc), gpgme_strerror(rc));

303

284

plaintext_length = -1;

304

285

if(debug){

305

286

gpgme_decrypt_result_t result;

306

result = gpgme_op_decrypt_result(mc.ctx);

287

result = gpgme_op_decrypt_result(mc->ctx);

307

288

if(result == NULL){

308

289

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

309

290

} else {

316

297

}

317

298

gpgme_recipient_t recipient;

318

299

recipient = result->recipients;

319

while(recipient != NULL){

320

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

321

gpgme_pubkey_algo_name(recipient->pubkey_algo));

322

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

323

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

324

recipient->status == GPG_ERR_NO_SECKEY

325

? "No" : "Yes");

326

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

}

327

310

}

328

311

}

329

312

}

343

326

344

327

*plaintext = NULL;

345

328

while(true){

346

plaintext_capacity = incbuffer(plaintext,

329

plaintext_capacity = adjustbuffer(plaintext,

347

330

(size_t)plaintext_length,

348

331

plaintext_capacity);

349

332

if(plaintext_capacity == 0){

350

perror("incbuffer");

333

perror("adjustbuffer");

351

334

plaintext_length = -1;

352

335

goto decrypt_end;

353

336

}

399

382

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

400

383

}

401

384

402

static int init_gnutls_global(const char *pubkeyfilename,

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

403

387

const char *seckeyfilename){

404

388

int ret;

405

389

423

407

}

424

408

425

409

/* OpenPGP credentials */

426

ret = gnutls_certificate_allocate_credentials(&mc.cred);

410

gnutls_certificate_allocate_credentials(&mc->cred);

427

411

if(ret != GNUTLS_E_SUCCESS){

428

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

412

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

413

* from

414

* -Wunreachable-code

415

*/

429

416

safer_gnutls_strerror(ret));

430

417

gnutls_global_deinit();

431

418

return -1;

438

425

}

439

426

440

427

ret = gnutls_certificate_set_openpgp_key_file

441

(mc.cred, pubkeyfilename, seckeyfilename,

428

(mc->cred, pubkeyfilename, seckeyfilename,

442

429

GNUTLS_OPENPGP_FMT_BASE64);

443

430

if(ret != GNUTLS_E_SUCCESS){

444

431

fprintf(stderr,

450

437

}

451

438

452

439

/* GnuTLS server initialization */

453

ret = gnutls_dh_params_init(&mc.dh_params);

440

ret = gnutls_dh_params_init(&mc->dh_params);

454

441

if(ret != GNUTLS_E_SUCCESS){

455

442

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

456

443

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

457

444

goto globalfail;

458

445

}

459

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

446

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

460

447

if(ret != GNUTLS_E_SUCCESS){

461

448

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

462

449

safer_gnutls_strerror(ret));

463

450

goto globalfail;

464

451

}

465

452

466

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

453

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

467

454

468

455

return 0;

469

456

470

457

globalfail:

471

458

472

gnutls_certificate_free_credentials(mc.cred);

459

gnutls_certificate_free_credentials(mc->cred);

473

460

gnutls_global_deinit();

474

gnutls_dh_params_deinit(mc.dh_params);

461

gnutls_dh_params_deinit(mc->dh_params);

475

462

return -1;

476

463

}

477

464

478

static int init_gnutls_session(gnutls_session_t *session){

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

479

467

int ret;

480

468

/* GnuTLS session creation */

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);

469

ret = gnutls_init(session, GNUTLS_SERVER);

487

470

if(ret != GNUTLS_E_SUCCESS){

488

471

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

489

472

safer_gnutls_strerror(ret));

491

474

492

475

{

493

476

const char *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);

477

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

501

478

if(ret != GNUTLS_E_SUCCESS){

502

479

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

503

480

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

507

484

}

508

485

}

509

486

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);

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

518

489

if(ret != GNUTLS_E_SUCCESS){

519

490

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

520

491

safer_gnutls_strerror(ret));

523

494

}

524

495

525

496

/* ignore client certificate if any. */

526

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

527

499

528

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

529

501

530

502

return 0;

531

503

}

537

509

/* Called when a Mandos server is found */

538

510

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

539

511

AvahiIfIndex if_index,

540

int af){

541

int ret, tcp_sd = -1;

512

mandos_context *mc){

513

int ret, tcp_sd;

542

514

ssize_t sret;

543

union {

544

struct sockaddr_in in;

545

struct sockaddr_in6 in6;

546

} to;

515

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

547

516

char *buffer = NULL;

548

char *decrypted_buffer = NULL;

517

char *decrypted_buffer;

549

518

size_t buffer_length = 0;

550

519

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

551

521

size_t written;

552

int retval = -1;

522

int retval = 0;

523

char interface[IF_NAMESIZE];

553

524

gnutls_session_t session;

554

int pf; /* Protocol family */

555

556

errno = 0;

557

558

if(quit_now){

559

errno = EINTR;

560

return -1;

561

}

562

563

switch(af){

564

case AF_INET6:

565

pf = PF_INET6;

566

break;

567

case AF_INET:

568

pf = PF_INET;

569

break;

570

default:

571

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

572

errno = EINVAL;

573

return -1;

574

}

575

576

ret = init_gnutls_session(&session);

525

526

ret = init_gnutls_session(mc, &session);

577

527

if(ret != 0){

578

528

return -1;

579

529

}

580

530

581

531

if(debug){

582

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

532

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

583

533

"\n", ip, port);

584

534

}

585

535

586

tcp_sd = socket(pf, SOCK_STREAM, 0);

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

587

537

if(tcp_sd < 0){

588

int e = errno;

589

538

perror("socket");

590

errno = e;

591

goto mandos_end;

539

return -1;

592

540

}

593

541

594

if(quit_now){

595

errno = EINTR;

596

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);

597

548

}

598

549

599

550

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

600

if(af == AF_INET6){

601

to.in6.sin6_family = (sa_family_t)af;

602

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

603

} else { /* IPv4 */

604

to.in.sin_family = (sa_family_t)af;

605

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

606

}

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);

607

555

if(ret < 0 ){

608

int e = errno;

609

556

perror("inet_pton");

610

errno = e;

611

goto mandos_end;

557

return -1;

612

558

}

613

559

if(ret == 0){

614

int e = errno;

615

560

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

616

errno = e;

617

goto mandos_end;

561

return -1;

618

562

}

619

if(af == AF_INET6){

620

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

621

-Wconversion and

622

-Wunreachable-code */

623

624

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

625

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

626

-Wunreachable-code*/

627

if(if_index == AVAHI_IF_UNSPEC){

628

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

629

" without a network interface\n");

630

errno = EINVAL;

631

goto mandos_end;

632

}

633

/* Set the network interface number as scope */

634

to.in6.sin6_scope_id = (uint32_t)if_index;

635

}

636

} else {

637

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

563

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

638

564

-Wconversion and

639

565

-Wunreachable-code */

640

}

641

566

642

if(quit_now){

643

errno = EINTR;

644

goto mandos_end;

645

}

567

to.in6.sin6_scope_id = (uint32_t)if_index;

646

568

647

569

if(debug){

648

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

649

char interface[IF_NAMESIZE];

650

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

651

perror("if_indextoname");

652

} else {

653

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

654

ip, interface, port);

655

}

656

} else {

657

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

658

port);

659

}

660

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

661

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

662

const char *pcret;

663

if(af == AF_INET6){

664

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

665

sizeof(addrstr));

666

} else {

667

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

668

sizeof(addrstr));

669

}

670

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){

671

575

perror("inet_ntop");

672

576

} else {

673

577

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

676

580

}

677

581

}

678

582

679

if(quit_now){

680

errno = EINTR;

681

goto mandos_end;

682

}

683

684

if(af == AF_INET6){

685

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

686

} else {

687

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

688

}

583

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

689

584

if(ret < 0){

690

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

691

int e = errno;

692

perror("connect");

693

errno = e;

694

}

695

goto mandos_end;

696

}

697

698

if(quit_now){

699

errno = EINTR;

700

goto mandos_end;

585

perror("connect");

586

return -1;

701

587

}

702

588

703

589

const char *out = mandos_protocol_version;

707

593

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

708

594

out_size - written));

709

595

if(ret == -1){

710

int e = errno;

711

596

perror("write");

712

errno = e;

597

retval = -1;

713

598

goto mandos_end;

714

599

}

715

600

written += (size_t)ret;

723

608

break;

724

609

}

725

610

}

726

727

if(quit_now){

728

errno = EINTR;

729

goto mandos_end;

730

}

731

611

}

732

612

733

613

if(debug){

734

614

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

735

615

}

736

616

737

if(quit_now){

738

errno = EINTR;

739

goto mandos_end;

740

}

741

742

617

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

743

618

744

if(quit_now){

745

errno = EINTR;

746

goto mandos_end;

747

}

748

749

do {

619

do{

750

620

ret = gnutls_handshake(session);

751

if(quit_now){

752

errno = EINTR;

753

goto mandos_end;

754

}

755

621

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

756

622

757

623

if(ret != GNUTLS_E_SUCCESS){

759

625

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

760

626

gnutls_perror(ret);

761

627

}

762

errno = EPROTO;

628

retval = -1;

763

629

goto mandos_end;

764

630

}

765

631

766

632

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

767

633

768

634

if(debug){

769

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

635

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

770

636

ip);

771

637

}

772

638

773

639

while(true){

774

775

if(quit_now){

776

errno = EINTR;

777

goto mandos_end;

778

}

779

780

buffer_capacity = incbuffer(&buffer, buffer_length,

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

781

641

buffer_capacity);

782

642

if(buffer_capacity == 0){

783

int e = errno;

784

perror("incbuffer");

785

errno = e;

786

goto mandos_end;

787

}

788

789

if(quit_now){

790

errno = EINTR;

643

perror("adjustbuffer");

644

retval = -1;

791

645

goto mandos_end;

792

646

}

793

647

802

656

case GNUTLS_E_AGAIN:

803

657

break;

804

658

case GNUTLS_E_REHANDSHAKE:

805

do {

659

do{

806

660

ret = gnutls_handshake(session);

807

808

if(quit_now){

809

errno = EINTR;

810

goto mandos_end;

811

}

812

661

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

813

662

if(ret < 0){

814

663

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

815

664

gnutls_perror(ret);

816

errno = EPROTO;

665

retval = -1;

817

666

goto mandos_end;

818

667

}

819

668

break;

820

669

default:

821

670

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

822

671

" encrypted session with Mandos server\n");

672

retval = -1;

823

673

gnutls_bye(session, GNUTLS_SHUT_RDWR);

824

errno = EIO;

825

674

goto mandos_end;

826

675

}

827

676

} else {

833

682

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

834

683

}

835

684

836

if(quit_now){

837

errno = EINTR;

838

goto mandos_end;

839

}

840

841

do {

842

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

846

}

847

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

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

848

686

849

687

if(buffer_length > 0){

850

ssize_t decrypted_buffer_size;

851

decrypted_buffer_size = pgp_packet_decrypt(buffer,

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

852

689

buffer_length,

853

690

&decrypted_buffer);

854

691

if(decrypted_buffer_size >= 0){

855

856

692

written = 0;

857

693

while(written < (size_t) decrypted_buffer_size){

858

if(quit_now){

859

errno = EINTR;

860

goto mandos_end;

861

}

862

863

694

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

864

695

(size_t)decrypted_buffer_size - written,

865

696

stdout);

866

697

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

867

int e = errno;

868

698

if(debug){

869

699

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

870

700

strerror(errno));

871

701

}

872

errno = e;

873

goto mandos_end;

702

retval = -1;

703

break;

874

704

}

875

705

written += (size_t)ret;

876

706

}

877

retval = 0;

707

free(decrypted_buffer);

708

} else {

709

retval = -1;

878

710

}

711

} else {

712

retval = -1;

879

713

}

880

714

881

715

/* Shutdown procedure */

882

716

883

717

mandos_end:

884

{

885

int e = errno;

886

free(decrypted_buffer);

887

free(buffer);

888

if(tcp_sd >= 0){

889

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

890

}

891

if(ret == -1){

892

if(e == 0){

893

e = errno;

894

}

895

perror("close");

896

}

897

gnutls_deinit(session);

898

if(quit_now){

899

e = EINTR;

900

retval = -1;

901

}

902

errno = e;

718

free(buffer);

719

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

720

if(ret == -1){

721

perror("close");

903

722

}

723

gnutls_deinit(session);

904

724

return retval;

905

725

}

906

726

907

727

static void resolve_callback(AvahiSServiceResolver *r,

908

728

AvahiIfIndex interface,

909

AvahiProtocol proto,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

910

730

AvahiResolverEvent event,

911

731

const char *name,

912

732

const char *type,

917

737

AVAHI_GCC_UNUSED AvahiStringList *txt,

918

738

AVAHI_GCC_UNUSED AvahiLookupResultFlags

919

739

flags,

920

AVAHI_GCC_UNUSED void* userdata){

740

void* userdata){

741

mandos_context *mc = userdata;

921

742

assert(r);

922

743

923

744

/* Called whenever a service has been resolved successfully or

924

745

timed out */

925

746

926

if(quit_now){

927

return;

928

}

929

930

747

switch(event){

931

748

default:

932

749

case AVAHI_RESOLVER_FAILURE:

933

750

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

934

751

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

935

avahi_strerror(avahi_server_errno(mc.server)));

752

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

936

753

break;

937

754

938

755

case AVAHI_RESOLVER_FOUND:

944

761

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

945

762

ip, (intmax_t)interface, port);

946

763

}

947

int ret = start_mandos_communication(ip, port, interface,

948

avahi_proto_to_af(proto));

764

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

949

765

if(ret == 0){

950

avahi_simple_poll_quit(mc.simple_poll);

766

avahi_simple_poll_quit(mc->simple_poll);

951

767

}

952

768

}

953

769

}

963

779

const char *domain,

964

780

AVAHI_GCC_UNUSED AvahiLookupResultFlags

965

781

flags,

966

AVAHI_GCC_UNUSED void* userdata){

782

void* userdata){

783

mandos_context *mc = userdata;

967

784

assert(b);

968

785

969

786

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

970

787

is removed from the LAN */

971

788

972

if(quit_now){

973

return;

974

}

975

976

789

switch(event){

977

790

default:

978

791

case AVAHI_BROWSER_FAILURE:

979

792

980

793

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

981

avahi_strerror(avahi_server_errno(mc.server)));

982

avahi_simple_poll_quit(mc.simple_poll);

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

983

796

return;

984

797

985

798

case AVAHI_BROWSER_NEW:

988

801

the callback function is called the Avahi server will free the

989

802

resolver for us. */

990

803

991

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

992

name, type, domain, protocol, 0,

993

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)))

994

808

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

995

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

809

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

996

810

break;

997

811

998

812

case AVAHI_BROWSER_REMOVE:

1007

821

}

1008

822

}

1009

823

1010

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

1011

static void handle_sigterm(int sig){

1012

if(quit_now){

1013

return;

1014

}

1015

quit_now = 1;

1016

signal_received = sig;

1017

int old_errno = errno;

1018

if(mc.simple_poll != NULL){

1019

avahi_simple_poll_quit(mc.simple_poll);

1020

}

1021

errno = old_errno;

1022

}

1023

1024

/*

1025

* This function determines if a directory entry in /sys/class/net

1026

* corresponds to an acceptable network device.

1027

* (This function is passed to scandir(3) as a filter function.)

1028

*/

1029

int good_interface(const struct dirent *if_entry){

1030

ssize_t ssret;

1031

char *flagname = NULL;

1032

if(if_entry->d_name[0] == '.'){

1033

return 0;

1034

}

1035

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1036

if_entry->d_name);

1037

if(ret < 0){

1038

perror("asprintf");

1039

return 0;

1040

}

1041

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1042

if(flags_fd == -1){

1043

perror("open");

1044

free(flagname);

1045

return 0;

1046

}

1047

free(flagname);

1048

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1049

/* read line from flags_fd */

1050

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1051

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1052

flagstring[(size_t)to_read] = '\0';

1053

if(flagstring == NULL){

1054

perror("malloc");

1055

close(flags_fd);

1056

return 0;

1057

}

1058

while(to_read > 0){

1059

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1060

(size_t)to_read));

1061

if(ssret == -1){

1062

perror("read");

1063

free(flagstring);

1064

close(flags_fd);

1065

return 0;

1066

}

1067

to_read -= ssret;

1068

if(ssret == 0){

1069

break;

1070

}

1071

}

1072

close(flags_fd);

1073

intmax_t tmpmax;

1074

char *tmp;

1075

errno = 0;

1076

tmpmax = strtoimax(flagstring, &tmp, 0);

1077

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

1078

and not (isspace(*tmp)))

1079

or tmpmax != (ifreq_flags)tmpmax){

1080

if(debug){

1081

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1082

flagstring, if_entry->d_name);

1083

}

1084

free(flagstring);

1085

return 0;

1086

}

1087

free(flagstring);

1088

ifreq_flags flags = (ifreq_flags)tmpmax;

1089

/* Reject the loopback device */

1090

if(flags & IFF_LOOPBACK){

1091

if(debug){

1092

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1093

if_entry->d_name);

1094

}

1095

return 0;

1096

}

1097

/* Accept point-to-point devices only if connect_to is specified */

1098

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1099

if(debug){

1100

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1101

if_entry->d_name);

1102

}

1103

return 1;

1104

}

1105

/* Otherwise, reject non-broadcast-capable devices */

1106

if(not (flags & IFF_BROADCAST)){

1107

if(debug){

1108

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1109

if_entry->d_name);

1110

}

1111

return 0;

1112

}

1113

/* Reject non-ARP interfaces (including dummy interfaces) */

1114

if(flags & IFF_NOARP){

1115

if(debug){

1116

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1117

if_entry->d_name);

1118

}

1119

return 0;

1120

}

1121

/* Accept this device */

1122

if(debug){

1123

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1124

if_entry->d_name);

1125

}

1126

return 1;

1127

}

1128

1129

824

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

1130

825

AvahiSServiceBrowser *sb = NULL;

1131

826

int error;

1132

827

int ret;

1133

828

intmax_t tmpmax;

1134

char *tmp;

829

int numchars;

1135

830

int exitcode = EXIT_SUCCESS;

1136

const char *interface = "";

831

const char *interface = "eth0";

1137

832

struct ifreq network;

1138

int sd = -1;

1139

bool take_down_interface = false;

833

int sd;

1140

834

uid_t uid;

1141

835

gid_t gid;

836

char *connect_to = NULL;

1142

837

char tempdir[] = "/tmp/mandosXXXXXX";

1143

838

bool tempdir_created = false;

1144

839

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1145

840

const char *seckey = PATHDIR "/" SECKEY;

1146

841

const char *pubkey = PATHDIR "/" PUBKEY;

1147

842

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

1148

846

bool gnutls_initialized = false;

1149

847

bool gpgme_initialized = false;

1150

float delay = 2.5f;

1151

1152

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1153

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1154

1155

uid = getuid();

1156

gid = getgid();

1157

1158

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

1159

errno = 0;

1160

ret = setgid(gid);

1161

if(ret == -1){

1162

perror("setgid");

1163

}

1164

1165

/* Lower user privileges (temporarily) */

1166

errno = 0;

1167

ret = seteuid(uid);

1168

if(ret == -1){

1169

perror("seteuid");

1170

}

1171

1172

if(quit_now){

1173

goto end;

1174

}

848

double delay = 2.5;

1175

849

1176

850

{

1177

851

struct argp_option options[] = {

1183

857

.group = 1 },

1184

858

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

1185

859

.arg = "NAME",

1186

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

1187

" Mandos servers",

860

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

861

" servers",

1188

862

.group = 1 },

1189

863

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

1190

864

.arg = "FILE",

1207

881

.arg = "SECONDS",

1208

882

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

1209

883

.group = 2 },

1210

/*

1211

* These reproduce what we would get without ARGP_NO_HELP

1212

*/

1213

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

1214

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

1215

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

1216

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

1217

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

1218

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

1219

884

{ .name = NULL }

1220

885

};

1221

886

1222

887

error_t parse_opt(int key, char *arg,

1223

888

struct argp_state *state){

1224

errno = 0;

1225

889

switch(key){

1226

890

case 128: /* --debug */

1227

891

debug = true;

1239

903

pubkey = arg;

1240

904

break;

1241

905

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

1242

errno = 0;

1243

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

1244

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

1245

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

1246

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

906

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

907

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

908

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

909

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

910

exit(EXIT_FAILURE);

1247

911

}

1248

912

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

1249

913

break;

1251

915

mc.priority = arg;

1252

916

break;

1253

917

case 131: /* --delay */

1254

errno = 0;

1255

delay = strtof(arg, &tmp);

1256

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

1257

argp_error(state, "Bad delay");

918

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

919

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

920

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

921

exit(EXIT_FAILURE);

1258

922

}

1259

923

break;

1260

/*

1261

* These reproduce what we would get without ARGP_NO_HELP

1262

*/

1263

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

1264

argp_state_help(state, state->out_stream,

1265

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1266

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1267

case -3: /* --usage */

1268

argp_state_help(state, state->out_stream,

1269

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1270

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

1271

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

1272

exit(argp_err_exit_status);

924

case ARGP_KEY_ARG:

925

argp_usage(state);

926

case ARGP_KEY_END:

1273

927

break;

1274

928

default:

1275

929

return ARGP_ERR_UNKNOWN;

1276

930

}

1277

return errno;

931

return 0;

1278

932

}

1279

933

1280

934

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

1281

935

.args_doc = "",

1282

936

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

1283

937

" passwords from a Mandos server" };

1284

ret = argp_parse(&argp, argc, argv,

1285

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1286

switch(ret){

1287

case 0:

1288

break;

1289

case ENOMEM:

1290

default:

1291

errno = ret;

1292

perror("argp_parse");

1293

exitcode = EX_OSERR;

1294

goto end;

1295

case EINVAL:

1296

exitcode = EX_USAGE;

1297

goto end;

1298

}

1299

}

1300

1301

if(not debug){

1302

avahi_set_log_function(empty_log);

1303

}

1304

1305

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

1306

struct dirent **direntries;

1307

ret = scandir(sys_class_net, &direntries, good_interface,

1308

alphasort);

1309

if(ret >= 1){

1310

/* Pick the first good interface */

1311

interface = strdup(direntries[0]->d_name);

1312

if(debug){

1313

fprintf(stderr, "Using interface \"%s\"\n", interface);

1314

}

1315

if(interface == NULL){

1316

perror("malloc");

1317

free(direntries);

1318

exitcode = EXIT_FAILURE;

1319

goto end;

1320

}

1321

free(direntries);

1322

} else {

1323

free(direntries);

1324

fprintf(stderr, "Could not find a network interface\n");

938

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

939

if(ret == ARGP_ERR_UNKNOWN){

940

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

1325

941

exitcode = EXIT_FAILURE;

1326

942

goto end;

1327

943

}

1328

944

}

1329

945

1330

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

1331

from the signal handler */

1332

/* Initialize the pseudo-RNG for Avahi */

1333

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

1334

mc.simple_poll = avahi_simple_poll_new();

1335

if(mc.simple_poll == NULL){

1336

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

1337

exitcode = EX_UNAVAILABLE;

1338

goto end;

1339

}

1340

1341

sigemptyset(&sigterm_action.sa_mask);

1342

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

1343

if(ret == -1){

1344

perror("sigaddset");

1345

exitcode = EX_OSERR;

1346

goto end;

1347

}

1348

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

1349

if(ret == -1){

1350

perror("sigaddset");

1351

exitcode = EX_OSERR;

1352

goto end;

1353

}

1354

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

1355

if(ret == -1){

1356

perror("sigaddset");

1357

exitcode = EX_OSERR;

1358

goto end;

1359

}

1360

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

1361

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

1362

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

1363

*/

1364

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

1365

if(ret == -1){

1366

perror("sigaction");

1367

return EX_OSERR;

1368

}

1369

if(old_sigterm_action.sa_handler != SIG_IGN){

1370

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

1371

if(ret == -1){

1372

perror("sigaction");

1373

exitcode = EX_OSERR;

1374

goto end;

1375

}

1376

}

1377

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

1378

if(ret == -1){

1379

perror("sigaction");

1380

return EX_OSERR;

1381

}

1382

if(old_sigterm_action.sa_handler != SIG_IGN){

1383

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

1384

if(ret == -1){

1385

perror("sigaction");

1386

exitcode = EX_OSERR;

1387

goto end;

1388

}

1389

}

1390

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

1391

if(ret == -1){

1392

perror("sigaction");

1393

return EX_OSERR;

1394

}

1395

if(old_sigterm_action.sa_handler != SIG_IGN){

1396

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

1397

if(ret == -1){

1398

perror("sigaction");

1399

exitcode = EX_OSERR;

1400

goto end;

1401

}

1402

}

1403

1404

946

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

1405

if(strcmp(interface, "none") != 0){

1406

if_index = (AvahiIfIndex) if_nametoindex(interface);

1407

if(if_index == 0){

1408

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

1409

exitcode = EX_UNAVAILABLE;

1410

goto end;

1411

}

1412

1413

if(quit_now){

1414

goto end;

1415

}

1416

1417

/* Re-raise priviliges */

1418

errno = 0;

1419

ret = seteuid(0);

1420

if(ret == -1){

1421

perror("seteuid");

1422

}

1423

947

{

1424

948

#ifdef __linux__

1425

949

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1426

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

950

messages to mess up the prompt */

1427

951

ret = klogctl(8, NULL, 5);

1428

bool restore_loglevel = true;

1429

952

if(ret == -1){

1430

restore_loglevel = false;

1431

953

perror("klogctl");

1432

954

}

1433

#endif /* __linux__ */

955

#endif

1434

956

1435

957

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1436

958

if(sd < 0){

1437

959

perror("socket");

1438

exitcode = EX_OSERR;

960

exitcode = EXIT_FAILURE;

1439

961

#ifdef __linux__

1440

if(restore_loglevel){

1441

ret = klogctl(7, NULL, 0);

1442

if(ret == -1){

1443

perror("klogctl");

1444

}

1445

}

1446

#endif /* __linux__ */

1447

/* Lower privileges */

1448

errno = 0;

1449

ret = seteuid(uid);

962

ret = klogctl(7, NULL, 0);

1450

963

if(ret == -1){

1451

perror("seteuid");

964

perror("klogctl");

1452

965

}

966

#endif

1453

967

goto end;

1454

968

}

1455

969

strcpy(network.ifr_name, interface);

1457

971

if(ret == -1){

1458

972

perror("ioctl SIOCGIFFLAGS");

1459

973

#ifdef __linux__

1460

if(restore_loglevel){

1461

ret = klogctl(7, NULL, 0);

1462

if(ret == -1){

1463

perror("klogctl");

1464

}

1465

}

1466

#endif /* __linux__ */

1467

exitcode = EX_OSERR;

1468

/* Lower privileges */

1469

errno = 0;

1470

ret = seteuid(uid);

974

ret = klogctl(7, NULL, 0);

1471

975

if(ret == -1){

1472

perror("seteuid");

976

perror("klogctl");

1473

977

}

978

#endif

979

exitcode = EXIT_FAILURE;

1474

980

goto end;

1475

981

}

1476

982

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

1477

983

network.ifr_flags |= IFF_UP;

1478

take_down_interface = true;

1479

984

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

1480

985

if(ret == -1){

1481

take_down_interface = false;

1482

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1483

exitcode = EX_OSERR;

986

perror("ioctl SIOCSIFFLAGS");

987

exitcode = EXIT_FAILURE;

1484

988

#ifdef __linux__

1485

if(restore_loglevel){

1486

ret = klogctl(7, NULL, 0);

1487

if(ret == -1){

1488

perror("klogctl");

1489

}

1490

}

1491

#endif /* __linux__ */

1492

/* Lower privileges */

1493

errno = 0;

1494

ret = seteuid(uid);

989

ret = klogctl(7, NULL, 0);

1495

990

if(ret == -1){

1496

perror("seteuid");

991

perror("klogctl");

1497

992

}

993

#endif

1498

994

goto end;

1499

995

}

1500

996

}

1512

1008

perror("nanosleep");

1513

1009

}

1514

1010

}

1515

if(not take_down_interface){

1516

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

1517

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

1518

if(ret == -1){

1519

perror("close");

1520

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1521

1014

}

1522

1015

#ifdef __linux__

1523

if(restore_loglevel){

1524

/* Restores kernel loglevel to default */

1525

ret = klogctl(7, NULL, 0);

1526

if(ret == -1){

1527

perror("klogctl");

1528

}

1529

}

1530

#endif /* __linux__ */

1531

/* Lower privileges */

1532

errno = 0;

1533

if(take_down_interface){

1534

/* Lower privileges */

1535

ret = seteuid(uid);

1536

if(ret == -1){

1537

perror("seteuid");

1538

}

1539

} else {

1540

/* Lower privileges permanently */

1541

ret = setuid(uid);

1542

if(ret == -1){

1543

perror("setuid");

1544

}

1545

}

1546

}

1547

1548

if(quit_now){

1549

goto end;

1550

}

1551

1552

ret = init_gnutls_global(pubkey, seckey);

1016

/* Restores kernel loglevel to default */

1017

ret = klogctl(7, NULL, 0);

1018

if(ret == -1){

1019

perror("klogctl");

1020

}

1021

#endif

1022

}

1023

1024

uid = getuid();

1025

gid = getgid();

1026

1027

setgid(gid);

1028

if(ret == -1){

1029

perror("setgid");

1030

}

1031

1032

ret = setuid(uid);

1033

if(ret == -1){

1034

perror("setuid");

1035

}

1036

1037

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

1553

1038

if(ret == -1){

1554

1039

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

1555

exitcode = EX_UNAVAILABLE;

1040

exitcode = EXIT_FAILURE;

1556

1041

goto end;

1557

1042

} else {

1558

1043

gnutls_initialized = true;

1559

1044

}

1560

1045

1561

if(quit_now){

1562

goto end;

1563

}

1564

1565

tempdir_created = true;

1566

1046

if(mkdtemp(tempdir) == NULL){

1567

tempdir_created = false;

1568

1047

perror("mkdtemp");

1569

1048

goto end;

1570

1049

}

1571

1572

if(quit_now){

1573

goto end;

1574

}

1575

1576

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

1050

tempdir_created = true;

1051

1052

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

1577

1053

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

1578

exitcode = EX_UNAVAILABLE;

1054

exitcode = EXIT_FAILURE;

1579

1055

goto end;

1580

1056

} else {

1581

1057

gpgme_initialized = true;

1582

1058

}

1583

1059

1584

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;

1585

1064

goto end;

1586

1065

}

1587

1066

1591

1070

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

1592

1071

if(address == NULL){

1593

1072

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

1594

exitcode = EX_USAGE;

1595

goto end;

1596

}

1597

1598

if(quit_now){

1599

goto end;

1600

}

1601

1073

exitcode = EXIT_FAILURE;

1074

goto end;

1075

}

1602

1076

uint16_t port;

1603

errno = 0;

1604

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

1605

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

1606

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'){

1607

1080

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

1608

exitcode = EX_USAGE;

1609

goto end;

1610

}

1611

1612

if(quit_now){

1613

goto end;

1614

}

1615

1081

exitcode = EXIT_FAILURE;

1082

goto end;

1083

}

1616

1084

port = (uint16_t)tmpmax;

1617

1085

*address = '\0';

1618

1086

address = connect_to;

1619

/* Colon in address indicates IPv6 */

1620

int af;

1621

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

1622

af = AF_INET6;

1087

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

1088

if(ret < 0){

1089

exitcode = EXIT_FAILURE;

1623

1090

} else {

1624

af = AF_INET;

1625

}

1626

1627

if(quit_now){

1628

goto end;

1629

}

1630

1631

while(not quit_now){

1632

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

1633

if(quit_now or ret == 0){

1634

break;

1635

}

1636

sleep(15);

1637

};

1638

1639

if (not quit_now){

1640

1091

exitcode = EXIT_SUCCESS;

1641

1092

}

1642

1643

1093

goto end;

1644

1094

}

1645

1095

1646

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;

1647

1108

goto end;

1648

1109

}

1649

1110

1669

1130

if(mc.server == NULL){

1670

1131

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

1671

1132

avahi_strerror(error));

1672

exitcode = EX_UNAVAILABLE;

1673

goto end;

1674

}

1675

1676

if(quit_now){

1133

exitcode = EXIT_FAILURE;

1677

1134

goto end;

1678

1135

}

1679

1136

1680

1137

/* Create the Avahi service browser */

1681

1138

sb = avahi_s_service_browser_new(mc.server, if_index,

1682

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1683

NULL, 0, browse_callback, NULL);

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1684

1141

if(sb == NULL){

1685

1142

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

1686

1143

avahi_strerror(avahi_server_errno(mc.server)));

1687

exitcode = EX_UNAVAILABLE;

1688

goto end;

1689

}

1690

1691

if(quit_now){

1144

exitcode = EXIT_FAILURE;

1692

1145

goto end;

1693

1146

}

1694

1147

1726

1179

gpgme_release(mc.ctx);

1727

1180

}

1728

1181

1729

/* Take down the network interface */

1730

if(take_down_interface){

1731

/* Re-raise priviliges */

1732

errno = 0;

1733

ret = seteuid(0);

1734

if(ret == -1){

1735

perror("seteuid");

1736

}

1737

if(geteuid() == 0){

1738

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

1739

if(ret == -1){

1740

perror("ioctl SIOCGIFFLAGS");

1741

} else if(network.ifr_flags & IFF_UP) {

1742

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

1743

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

1744

if(ret == -1){

1745

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1746

}

1747

}

1748

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

1749

if(ret == -1){

1750

perror("close");

1751

}

1752

/* Lower privileges permanently */

1753

errno = 0;

1754

ret = setuid(uid);

1755

if(ret == -1){

1756

perror("setuid");

1757

}

1758

}

1759

}

1760

1761

1182

/* Removes the temp directory used by GPGME */

1762

1183

if(tempdir_created){

1763

1184

DIR *d;

1802

1223

}

1803

1224

}

1804

1225

1805

if(quit_now){

1806

sigemptyset(&old_sigterm_action.sa_mask);

1807

old_sigterm_action.sa_handler = SIG_DFL;

1808

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1809

&old_sigterm_action,

1810

NULL));

1811

if(ret == -1){

1812

perror("sigaction");

1813

}

1814

do {

1815

ret = raise(signal_received);

1816

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

1817

if(ret != 0){

1818

perror("raise");

1819

abort();

1820

}

1821

TEMP_FAILURE_RETRY(pause());

1822

}

1823

1824

1226

return exitcode;

1825

1227

}