/mandos/release : revision 237.7.39

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

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() */

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41

38

42

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

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

42

45

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

43

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

44

srand() */

45

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

46

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

47

strtof(), abort() */

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

46

49

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

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50

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

48

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

51

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

49

52

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

50

53

sockaddr_in6, PF_INET6,

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SOCK_STREAM, INET6_ADDRSTRLEN,

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

53

DIR */

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SOCK_STREAM, uid_t, gid_t, open(),

55

opendir(), DIR */

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56

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

55

57

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

56

struct in6_addr, inet_pton(),

57

connect() */

58

inet_pton(), connect() */

58

59

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

59

60

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

60

61

*/

61

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

62

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

63

strtoimax() */

62

64

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

63

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

64

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

65

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

66

program_invocation_short_name */

67

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

65

68

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

66

69

SIOCSIFFLAGS, if_indextoname(),

67

70

if_nametoindex(), IF_NAMESIZE */

68

#include <netinet/in.h>

71

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

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INET_ADDRSTRLEN, INET6_ADDRSTRLEN

73

*/

69

74

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

70

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

71

setgid() */

72

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

73

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

75

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

76

setgid(), pause() */

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

78

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

74

79

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

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80

argp_state, struct argp,

76

81

argp_parse(), ARGP_KEY_ARG,

77

82

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

83

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

84

sigaction(), SIGTERM, sig_atomic_t,

85

raise() */

86

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

87

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

88

78

89

#ifdef __linux__

79

90

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

80

#endif

91

#endif /* __linux__ */

81

92

82

93

/* Avahi */

83

94

/* All Avahi types, constants and functions

117

128

static const char mandos_protocol_version[] = "1";

118

129

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

119

130

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

131

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

132

char *connect_to = NULL;

133

134

/* Doubly linked list that need to be circularly linked when used */

135

typedef struct server{

136

const char *ip;

137

uint16_t port;

138

AvahiIfIndex if_index;

139

int af;

140

struct timespec last_seen;

141

struct server *next;

142

struct server *prev;

143

} server;

120

144

121

145

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

122

146

typedef struct {

127

151

gnutls_dh_params_t dh_params;

128

152

const char *priority;

129

153

gpgme_ctx_t ctx;

154

server *current_server;

130

155

} mandos_context;

131

156

157

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

158

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

159

.dh_bits = 1024, .priority = "SECURE256"

160

":!CTYPE-X.509:+CTYPE-OPENPGP",

161

.current_server = NULL };

162

163

sig_atomic_t quit_now = 0;

164

int signal_received = 0;

165

166

/* Function to use when printing errors */

167

void perror_plus(const char *print_text){

168

fprintf(stderr, "Mandos plugin %s: ",

169

program_invocation_short_name);

170

perror(print_text);

171

}

172

132

173

/*

133

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

134

* "buffer_capacity" is how much is currently allocated,

174

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

175

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

135

176

* "buffer_length" is how much is already used.

136

177

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

178

size_t incbuffer(char **buffer, size_t buffer_length,

138

179

size_t buffer_capacity){

139

180

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

181

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

146

187

return buffer_capacity;

147

188

}

148

189

190

/* Add server to set of servers to retry periodically */

191

int add_server(const char *ip, uint16_t port,

192

AvahiIfIndex if_index,

193

int af){

194

int ret;

195

server *new_server = malloc(sizeof(server));

196

if(new_server == NULL){

197

perror_plus("malloc");

198

return -1;

199

}

200

*new_server = (server){ .ip = strdup(ip),

201

.port = port,

202

.if_index = if_index,

203

.af = af };

204

if(new_server->ip == NULL){

205

perror_plus("strdup");

206

return -1;

207

}

208

/* Special case of first server */

209

if (mc.current_server == NULL){

210

new_server->next = new_server;

211

new_server->prev = new_server;

212

mc.current_server = new_server;

213

/* Place the new server last in the list */

214

} else {

215

new_server->next = mc.current_server;

216

new_server->prev = mc.current_server->prev;

217

new_server->prev->next = new_server;

218

mc.current_server->prev = new_server;

219

}

220

ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

221

if(ret == -1){

222

perror_plus("clock_gettime");

223

return -1;

224

}

225

return 0;

226

}

227

149

228

/*

150

229

* Initialize GPGME.

151

230

*/

152

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

231

static bool init_gpgme(const char *seckey,

153

232

const char *pubkey, const char *tempdir){

154

int ret;

155

233

gpgme_error_t rc;

156

234

gpgme_engine_info_t engine_info;

157

235

160

238

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

161

239

*/

162

240

bool import_key(const char *filename){

241

int ret;

163

242

int fd;

164

243

gpgme_data_t pgp_data;

165

244

166

245

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

167

246

if(fd == -1){

168

perror("open");

247

perror_plus("open");

169

248

return false;

170

249

}

171

250

176

255

return false;

177

256

}

178

257

179

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

258

rc = gpgme_op_import(mc.ctx, pgp_data);

180

259

if(rc != GPG_ERR_NO_ERROR){

181

260

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

182

261

gpgme_strsource(rc), gpgme_strerror(rc));

185

264

186

265

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

187

266

if(ret == -1){

188

perror("close");

267

perror_plus("close");

189

268

}

190

269

gpgme_data_release(pgp_data);

191

270

return true;

192

271

}

193

272

194

273

if(debug){

195

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

274

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

196

275

}

197

276

198

277

/* Init GPGME */

225

304

}

226

305

227

306

/* Create new GPGME "context" */

228

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

307

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

229

308

if(rc != GPG_ERR_NO_ERROR){

230

309

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

231

310

gpgme_strsource(rc), gpgme_strerror(rc));

236

315

return false;

237

316

}

238

317

239

return true;

318

return true;

240

319

}

241

320

242

321

/*

243

322

* Decrypt OpenPGP data.

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323

* Returns -1 on error

245

324

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

325

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

326

size_t crypto_size,

249

327

char **plaintext){

250

328

gpgme_data_t dh_crypto, dh_plain;

277

355

278

356

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

279

357

data buffer */

280

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

358

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

281

359

if(rc != GPG_ERR_NO_ERROR){

282

360

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

283

361

gpgme_strsource(rc), gpgme_strerror(rc));

284

362

plaintext_length = -1;

285

363

if(debug){

286

364

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

365

result = gpgme_op_decrypt_result(mc.ctx);

288

366

if(result == NULL){

289

367

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

290

368

} else {

297

375

}

298

376

gpgme_recipient_t recipient;

299

377

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

}

378

while(recipient != NULL){

379

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

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

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

382

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

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

385

recipient = recipient->next;

310

386

}

311

387

}

312

388

}

319

395

320

396

/* Seek back to the beginning of the GPGME plaintext data buffer */

321

397

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

322

perror("gpgme_data_seek");

398

perror_plus("gpgme_data_seek");

323

399

plaintext_length = -1;

324

400

goto decrypt_end;

325

401

}

326

402

327

403

*plaintext = NULL;

328

404

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

405

plaintext_capacity = incbuffer(plaintext,

330

406

(size_t)plaintext_length,

331

407

plaintext_capacity);

332

408

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

409

perror_plus("incbuffer");

334

410

plaintext_length = -1;

335

411

goto decrypt_end;

336

412

}

343

419

break;

344

420

}

345

421

if(ret < 0){

346

perror("gpgme_data_read");

422

perror_plus("gpgme_data_read");

347

423

plaintext_length = -1;

348

424

goto decrypt_end;

349

425

}

382

458

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

383

459

}

384

460

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

461

static int init_gnutls_global(const char *pubkeyfilename,

387

462

const char *seckeyfilename){

388

463

int ret;

389

464

407

482

}

408

483

409

484

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

411

486

if(ret != GNUTLS_E_SUCCESS){

412

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

413

* from

414

* -Wunreachable-code

415

*/

487

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

416

488

safer_gnutls_strerror(ret));

417

489

gnutls_global_deinit();

418

490

return -1;

425

497

}

426

498

427

499

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

500

(mc.cred, pubkeyfilename, seckeyfilename,

429

501

GNUTLS_OPENPGP_FMT_BASE64);

430

502

if(ret != GNUTLS_E_SUCCESS){

431

503

fprintf(stderr,

437

509

}

438

510

439

511

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

512

ret = gnutls_dh_params_init(&mc.dh_params);

441

513

if(ret != GNUTLS_E_SUCCESS){

442

514

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

443

515

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

444

516

goto globalfail;

445

517

}

446

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

518

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

447

519

if(ret != GNUTLS_E_SUCCESS){

448

520

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

449

521

safer_gnutls_strerror(ret));

450

522

goto globalfail;

451

523

}

452

524

453

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

525

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

526

455

527

return 0;

456

528

457

529

globalfail:

458

530

459

gnutls_certificate_free_credentials(mc->cred);

531

gnutls_certificate_free_credentials(mc.cred);

460

532

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

533

gnutls_dh_params_deinit(mc.dh_params);

462

534

return -1;

463

535

}

464

536

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

537

static int init_gnutls_session(gnutls_session_t *session){

467

538

int ret;

468

539

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

540

do {

541

ret = gnutls_init(session, GNUTLS_SERVER);

542

if(quit_now){

543

return -1;

544

}

545

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

470

546

if(ret != GNUTLS_E_SUCCESS){

471

547

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

472

548

safer_gnutls_strerror(ret));

474

550

475

551

{

476

552

const char *err;

477

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

553

do {

554

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

555

if(quit_now){

556

gnutls_deinit(*session);

557

return -1;

558

}

559

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

478

560

if(ret != GNUTLS_E_SUCCESS){

479

561

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

480

562

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

484

566

}

485

567

}

486

568

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

569

do {

570

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

571

mc.cred);

572

if(quit_now){

573

gnutls_deinit(*session);

574

return -1;

575

}

576

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

489

577

if(ret != GNUTLS_E_SUCCESS){

490

578

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

491

579

safer_gnutls_strerror(ret));

494

582

}

495

583

496

584

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

585

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

586

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

588

502

589

return 0;

503

590

}

509

596

/* Called when a Mandos server is found */

510

597

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

511

598

AvahiIfIndex if_index,

512

mandos_context *mc){

513

int ret, tcp_sd;

599

int af){

600

int ret, tcp_sd = -1;

514

601

ssize_t sret;

515

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

602

union {

603

struct sockaddr_in in;

604

struct sockaddr_in6 in6;

605

} to;

516

606

char *buffer = NULL;

517

char *decrypted_buffer;

607

char *decrypted_buffer = NULL;

518

608

size_t buffer_length = 0;

519

609

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

521

610

size_t written;

522

int retval = 0;

523

char interface[IF_NAMESIZE];

611

int retval = -1;

524

612

gnutls_session_t session;

525

526

ret = init_gnutls_session(mc, &session);

613

int pf; /* Protocol family */

614

615

errno = 0;

616

617

if(quit_now){

618

errno = EINTR;

619

return -1;

620

}

621

622

switch(af){

623

case AF_INET6:

624

pf = PF_INET6;

625

break;

626

case AF_INET:

627

pf = PF_INET;

628

break;

629

default:

630

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

631

errno = EINVAL;

632

return -1;

633

}

634

635

ret = init_gnutls_session(&session);

527

636

if(ret != 0){

528

637

return -1;

529

638

}

530

639

531

640

if(debug){

532

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

641

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

533

642

"\n", ip, port);

534

643

}

535

644

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

537

646

if(tcp_sd < 0){

538

perror("socket");

539

return -1;

647

int e = errno;

648

perror_plus("socket");

649

errno = e;

650

goto mandos_end;

540

651

}

541

652

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);

653

if(quit_now){

654

errno = EINTR;

655

goto mandos_end;

548

656

}

549

657

550

658

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

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);

659

if(af == AF_INET6){

660

to.in6.sin6_family = (sa_family_t)af;

661

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

662

} else { /* IPv4 */

663

to.in.sin_family = (sa_family_t)af;

664

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

665

}

555

666

if(ret < 0 ){

556

perror("inet_pton");

557

return -1;

667

int e = errno;

668

perror_plus("inet_pton");

669

errno = e;

670

goto mandos_end;

558

671

}

559

672

if(ret == 0){

673

int e = errno;

560

674

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

561

return -1;

675

errno = e;

676

goto mandos_end;

562

677

}

563

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

678

if(af == AF_INET6){

679

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

680

-Wconversion and

681

-Wunreachable-code */

682

683

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

684

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

685

-Wunreachable-code*/

686

if(if_index == AVAHI_IF_UNSPEC){

687

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

688

" without a network interface\n");

689

errno = EINVAL;

690

goto mandos_end;

691

}

692

/* Set the network interface number as scope */

693

to.in6.sin6_scope_id = (uint32_t)if_index;

694

}

695

} else {

696

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

564

697

-Wconversion and

565

698

-Wunreachable-code */

699

}

566

700

567

to.in6.sin6_scope_id = (uint32_t)if_index;

701

if(quit_now){

702

errno = EINTR;

703

goto mandos_end;

704

}

568

705

569

706

if(debug){

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){

575

perror("inet_ntop");

707

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

708

char interface[IF_NAMESIZE];

709

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

710

perror_plus("if_indextoname");

711

} else {

712

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

713

ip, interface, port);

714

}

715

} else {

716

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

717

port);

718

}

719

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

720

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

721

const char *pcret;

722

if(af == AF_INET6){

723

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

724

sizeof(addrstr));

725

} else {

726

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

727

sizeof(addrstr));

728

}

729

if(pcret == NULL){

730

perror_plus("inet_ntop");

576

731

} else {

577

732

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

578

733

fprintf(stderr, "Canonical address form: %s\n", addrstr);

580

735

}

581

736

}

582

737

583

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

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

743

if(af == AF_INET6){

744

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

745

} else {

746

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

747

}

584

748

if(ret < 0){

585

perror("connect");

586

return -1;

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

587

760

}

588

761

589

762

const char *out = mandos_protocol_version;

593

766

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

594

767

out_size - written));

595

768

if(ret == -1){

596

perror("write");

597

retval = -1;

769

int e = errno;

770

perror_plus("write");

771

errno = e;

598

772

goto mandos_end;

599

773

}

600

774

written += (size_t)ret;

608

782

break;

609

783

}

610

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

789

}

611

790

}

612

791

613

792

if(debug){

614

793

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

615

794

}

616

795

796

if(quit_now){

797

errno = EINTR;

798

goto mandos_end;

799

}

800

801

/* Spurious warning from -Wint-to-pointer-cast */

617

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

618

803

619

do{

804

if(quit_now){

805

errno = EINTR;

806

goto mandos_end;

807

}

808

809

do {

620

810

ret = gnutls_handshake(session);

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

621

815

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

622

816

623

817

if(ret != GNUTLS_E_SUCCESS){

625

819

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

626

820

gnutls_perror(ret);

627

821

}

628

retval = -1;

822

errno = EPROTO;

629

823

goto mandos_end;

630

824

}

631

825

632

826

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

633

827

634

828

if(debug){

635

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

829

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

636

830

ip);

637

831

}

638

832

639

833

while(true){

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

834

835

if(quit_now){

836

errno = EINTR;

837

goto mandos_end;

838

}

839

840

buffer_capacity = incbuffer(&buffer, buffer_length,

641

841

buffer_capacity);

642

842

if(buffer_capacity == 0){

643

perror("adjustbuffer");

644

retval = -1;

843

int e = errno;

844

perror_plus("incbuffer");

845

errno = e;

846

goto mandos_end;

847

}

848

849

if(quit_now){

850

errno = EINTR;

645

851

goto mandos_end;

646

852

}

647

853

656

862

case GNUTLS_E_AGAIN:

657

863

break;

658

864

case GNUTLS_E_REHANDSHAKE:

659

do{

865

do {

660

866

ret = gnutls_handshake(session);

867

868

if(quit_now){

869

errno = EINTR;

870

goto mandos_end;

871

}

661

872

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

662

873

if(ret < 0){

663

874

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

664

875

gnutls_perror(ret);

665

retval = -1;

876

errno = EPROTO;

666

877

goto mandos_end;

667

878

}

668

879

break;

669

880

default:

670

881

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

671

882

" encrypted session with Mandos server\n");

672

retval = -1;

673

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

884

errno = EIO;

674

885

goto mandos_end;

675

886

}

676

887

} else {

682

893

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

683

894

}

684

895

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

896

if(quit_now){

897

errno = EINTR;

898

goto mandos_end;

899

}

900

901

do {

902

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

903

if(quit_now){

904

errno = EINTR;

905

goto mandos_end;

906

}

907

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

686

908

687

909

if(buffer_length > 0){

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

910

ssize_t decrypted_buffer_size;

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

689

912

buffer_length,

690

913

&decrypted_buffer);

691

914

if(decrypted_buffer_size >= 0){

915

692

916

written = 0;

693

917

while(written < (size_t) decrypted_buffer_size){

918

if(quit_now){

919

errno = EINTR;

920

goto mandos_end;

921

}

922

694

923

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

695

924

(size_t)decrypted_buffer_size - written,

696

925

stdout);

697

926

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

927

int e = errno;

698

928

if(debug){

699

929

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

700

930

strerror(errno));

701

931

}

702

retval = -1;

703

break;

932

errno = e;

933

goto mandos_end;

704

934

}

705

935

written += (size_t)ret;

706

936

}

707

free(decrypted_buffer);

708

} else {

709

retval = -1;

937

retval = 0;

710

938

}

711

} else {

712

retval = -1;

713

939

}

714

940

715

941

/* Shutdown procedure */

716

942

717

943

mandos_end:

718

free(buffer);

719

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

720

if(ret == -1){

721

perror("close");

944

{

945

int e = errno;

946

free(decrypted_buffer);

947

free(buffer);

948

if(tcp_sd >= 0){

949

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

950

}

951

if(ret == -1){

952

if(e == 0){

953

e = errno;

954

}

955

perror_plus("close");

956

}

957

gnutls_deinit(session);

958

errno = e;

959

if(quit_now){

960

errno = EINTR;

961

retval = -1;

962

}

722

963

}

723

gnutls_deinit(session);

724

964

return retval;

725

965

}

726

966

727

967

static void resolve_callback(AvahiSServiceResolver *r,

728

968

AvahiIfIndex interface,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

969

AvahiProtocol proto,

730

970

AvahiResolverEvent event,

731

971

const char *name,

732

972

const char *type,

737

977

AVAHI_GCC_UNUSED AvahiStringList *txt,

738

978

AVAHI_GCC_UNUSED AvahiLookupResultFlags

739

979

flags,

740

void* userdata){

741

mandos_context *mc = userdata;

980

AVAHI_GCC_UNUSED void* userdata){

742

981

assert(r);

743

982

744

983

/* Called whenever a service has been resolved successfully or

745

984

timed out */

746

985

986

if(quit_now){

987

return;

988

}

989

747

990

switch(event){

748

991

default:

749

992

case AVAHI_RESOLVER_FAILURE:

750

993

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

751

994

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

752

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

995

avahi_strerror(avahi_server_errno(mc.server)));

753

996

break;

754

997

755

998

case AVAHI_RESOLVER_FOUND:

761

1004

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

762

1005

ip, (intmax_t)interface, port);

763

1006

}

764

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

1007

int ret = start_mandos_communication(ip, port, interface,

1008

avahi_proto_to_af(proto));

765

1009

if(ret == 0){

766

avahi_simple_poll_quit(mc->simple_poll);

1010

avahi_simple_poll_quit(mc.simple_poll);

1011

} else {

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

767

1014

}

768

1015

}

769

1016

}

779

1026

const char *domain,

780

1027

AVAHI_GCC_UNUSED AvahiLookupResultFlags

781

1028

flags,

782

void* userdata){

783

mandos_context *mc = userdata;

1029

AVAHI_GCC_UNUSED void* userdata){

784

1030

assert(b);

785

1031

786

1032

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

787

1033

is removed from the LAN */

788

1034

1035

if(quit_now){

1036

return;

1037

}

1038

789

1039

switch(event){

790

1040

default:

791

1041

case AVAHI_BROWSER_FAILURE:

792

1042

793

1043

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

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

1044

avahi_strerror(avahi_server_errno(mc.server)));

1045

avahi_simple_poll_quit(mc.simple_poll);

796

1046

return;

797

1047

798

1048

case AVAHI_BROWSER_NEW:

801

1051

the callback function is called the Avahi server will free the

802

1052

resolver for us. */

803

1053

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

1054

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

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

808

1057

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

809

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

1058

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

810

1059

break;

811

1060

812

1061

case AVAHI_BROWSER_REMOVE:

821

1070

}

822

1071

}

823

1072

1073

/* Signal handler that stops main loop after SIGTERM */

1074

static void handle_sigterm(int sig){

1075

if(quit_now){

1076

return;

1077

}

1078

quit_now = 1;

1079

signal_received = sig;

1080

int old_errno = errno;

1081

/* set main loop to exit */

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1084

}

1085

errno = old_errno;

1086

}

1087

1088

/*

1089

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

1090

* corresponds to an acceptable network device.

1091

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

1092

*/

1093

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

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

1097

return 0;

1098

}

1099

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

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

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

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

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

1113

/* read line from flags_fd */

1114

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

1115

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

1116

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

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

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

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

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

1141

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

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1144

if(debug){

1145

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

1146

flagstring, if_entry->d_name);

1147

}

1148

free(flagstring);

1149

return 0;

1150

}

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1153

/* Reject the loopback device */

1154

if(flags & IFF_LOOPBACK){

1155

if(debug){

1156

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

1157

if_entry->d_name);

1158

}

1159

return 0;

1160

}

1161

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

1162

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

1163

if(debug){

1164

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

1165

if_entry->d_name);

1166

}

1167

return 1;

1168

}

1169

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

1170

if(not (flags & IFF_BROADCAST)){

1171

if(debug){

1172

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

1173

if_entry->d_name);

1174

}

1175

return 0;

1176

}

1177

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

1178

if(flags & IFF_NOARP){

1179

if(debug){

1180

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

1181

if_entry->d_name);

1182

}

1183

return 0;

1184

}

1185

/* Accept this device */

1186

if(debug){

1187

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

1188

if_entry->d_name);

1189

}

1190

return 1;

1191

}

1192

1193

int notdotentries(const struct dirent *direntry){

1194

/* Skip "." and ".." */

1195

if(direntry->d_name[0] == '.'

1196

and (direntry->d_name[1] == '\0'

1197

or (direntry->d_name[1] == '.'

1198

and direntry->d_name[2] == '\0'))){

1199

return 0;

1200

}

1201

return 1;

1202

}

1203

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1205

int ret;

1206

struct timespec now;

1207

struct timespec waited_time;

1208

intmax_t block_time;

1209

1210

while(true){

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1215

}

1216

ret = avahi_simple_poll_iterate(s, -1);

1217

} else {

1218

if (debug){

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1221

}

1222

/* the current time */

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1224

if(ret == -1){

1225

perror_plus("clock_gettime");

1226

return -1;

1227

}

1228

/* Calculating in ms how long time between now and server

1229

who we visted longest time ago. Now - last seen. */

1230

waited_time.tv_sec = (now.tv_sec

1231

- mc.current_server->last_seen.tv_sec);

1232

waited_time.tv_nsec = (now.tv_nsec

1233

- mc.current_server->last_seen.tv_nsec);

1234

/* total time is 10s/10,000ms.

1235

Converting to s from ms by dividing by 1,000,

1236

and ns to ms by dividing by 1,000,000. */

1237

block_time = ((retry_interval

1238

- ((intmax_t)waited_time.tv_sec * 1000))

1239

- ((intmax_t)waited_time.tv_nsec / 1000000));

1240

1241

if (debug){

1242

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1243

}

1244

1245

if(block_time <= 0){

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

1250

if(ret == 0){

1251

avahi_simple_poll_quit(mc.simple_poll);

1252

return 0;

1253

}

1254

ret = clock_gettime(CLOCK_MONOTONIC,

1255

&mc.current_server->last_seen);

1256

if(ret == -1){

1257

perror_plus("clock_gettime");

1258

return -1;

1259

}

1260

mc.current_server = mc.current_server->next;

1261

block_time = 0; /* Call avahi to find new Mandos

1262

servers, but don't block */

1263

}

1264

1265

ret = avahi_simple_poll_iterate(s, (int)block_time);

1266

}

1267

if(ret != 0){

1268

if (ret > 0 or errno != EINTR) {

1269

return (ret != 1) ? ret : 0;

1270

}

1271

}

1272

}

1273

}

1274

824

1275

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

825

1276

AvahiSServiceBrowser *sb = NULL;

826

1277

int error;

827

1278

int ret;

828

1279

intmax_t tmpmax;

829

int numchars;

1280

char *tmp;

830

1281

int exitcode = EXIT_SUCCESS;

831

const char *interface = "eth0";

1282

const char *interface = "";

832

1283

struct ifreq network;

833

int sd;

1284

int sd = -1;

1285

bool take_down_interface = false;

834

1286

uid_t uid;

835

1287

gid_t gid;

836

char *connect_to = NULL;

837

1288

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

838

1289

bool tempdir_created = false;

839

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

840

1291

const char *seckey = PATHDIR "/" SECKEY;

841

1292

const char *pubkey = PATHDIR "/" PUBKEY;

842

1293

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

846

1294

bool gnutls_initialized = false;

847

1295

bool gpgme_initialized = false;

848

double delay = 2.5;

1296

float delay = 2.5f;

1297

double retry_interval = 10; /* 10s between trying a server and

1298

retrying the same server again */

1299

1300

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1301

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1302

1303

uid = getuid();

1304

gid = getgid();

1305

1306

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

1307

errno = 0;

1308

ret = setgid(gid);

1309

if(ret == -1){

1310

perror_plus("setgid");

1311

}

1312

1313

/* Lower user privileges (temporarily) */

1314

errno = 0;

1315

ret = seteuid(uid);

1316

if(ret == -1){

1317

perror_plus("seteuid");

1318

}

1319

1320

if(quit_now){

1321

goto end;

1322

}

849

1323

850

1324

{

851

1325

struct argp_option options[] = {

857

1331

.group = 1 },

858

1332

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

859

1333

.arg = "NAME",

860

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

861

" servers",

1334

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

1335

" Mandos servers",

862

1336

.group = 1 },

863

1337

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

864

1338

.arg = "FILE",

881

1355

.arg = "SECONDS",

882

1356

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

883

1357

.group = 2 },

1358

{ .name = "retry", .key = 132,

1359

.arg = "SECONDS",

1360

.doc = "Retry interval used when denied by the mandos server",

1361

.group = 2 },

1362

/*

1363

* These reproduce what we would get without ARGP_NO_HELP

1364

*/

1365

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

1366

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

1367

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

1368

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

1369

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

1370

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

884

1371

{ .name = NULL }

885

1372

};

886

1373

887

1374

error_t parse_opt(int key, char *arg,

888

1375

struct argp_state *state){

1376

errno = 0;

889

1377

switch(key){

890

1378

case 128: /* --debug */

891

1379

debug = true;

903

1391

pubkey = arg;

904

1392

break;

905

1393

case 129: /* --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);

1394

errno = 0;

1395

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

1396

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

1397

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

1398

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

911

1399

}

912

1400

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

913

1401

break;

915

1403

mc.priority = arg;

916

1404

break;

917

1405

case 131: /* --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);

1406

errno = 0;

1407

delay = strtof(arg, &tmp);

1408

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

1409

argp_error(state, "Bad delay");

1410

}

1411

case 132: /* --retry */

1412

errno = 0;

1413

retry_interval = strtod(arg, &tmp);

1414

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

1415

or (retry_interval * 1000) > INT_MAX

1416

or retry_interval < 0){

1417

argp_error(state, "Bad retry interval");

922

1418

}

923

1419

break;

924

case ARGP_KEY_ARG:

925

argp_usage(state);

926

case ARGP_KEY_END:

1420

/*

1421

* These reproduce what we would get without ARGP_NO_HELP

1422

*/

1423

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

1424

argp_state_help(state, state->out_stream,

1425

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1426

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1427

case -3: /* --usage */

1428

argp_state_help(state, state->out_stream,

1429

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1430

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

1431

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

1432

exit(argp_err_exit_status);

927

1433

break;

928

1434

default:

929

1435

return ARGP_ERR_UNKNOWN;

930

1436

}

931

return 0;

1437

return errno;

932

1438

}

933

1439

934

1440

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

935

1441

.args_doc = "",

936

1442

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

937

1443

" passwords from a Mandos server" };

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");

1444

ret = argp_parse(&argp, argc, argv,

1445

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1446

switch(ret){

1447

case 0:

1448

break;

1449

case ENOMEM:

1450

default:

1451

errno = ret;

1452

perror_plus("argp_parse");

1453

exitcode = EX_OSERR;

1454

goto end;

1455

case EINVAL:

1456

exitcode = EX_USAGE;

1457

goto end;

1458

}

1459

}

1460

1461

{

1462

/* Work around Debian bug #633582:

1463

<http://bugs.debian.org/633582> */

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

int seckey_fd = open(PATHDIR "/" SECKEY, O_RDONLY);

1474

if(seckey_fd == -1){

1475

perror_plus("open");

1476

} else {

1477

ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));

1478

if(ret == -1){

1479

perror_plus("fstat");

1480

} else {

1481

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1482

ret = fchown(seckey_fd, uid, gid);

1483

if(ret == -1){

1484

perror_plus("fchown");

1485

}

1486

}

1487

}

1488

TEMP_FAILURE_RETRY(close(seckey_fd));

1489

}

1490

1491

int pubkey_fd = open(PATHDIR "/" PUBKEY, O_RDONLY);

1492

if(pubkey_fd == -1){

1493

perror_plus("open");

1494

} else {

1495

ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));

1496

if(ret == -1){

1497

perror_plus("fstat");

1498

} else {

1499

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1500

ret = fchown(pubkey_fd, uid, gid);

1501

if(ret == -1){

1502

perror_plus("fchown");

1503

}

1504

}

1505

}

1506

TEMP_FAILURE_RETRY(close(pubkey_fd));

1507

}

1508

1509

/* Lower privileges */

1510

errno = 0;

1511

ret = seteuid(uid);

1512

if(ret == -1){

1513

perror_plus("seteuid");

1514

}

1515

}

1516

1517

if(not debug){

1518

avahi_set_log_function(empty_log);

1519

}

1520

1521

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

1522

struct dirent **direntries;

1523

ret = scandir(sys_class_net, &direntries, good_interface,

1524

alphasort);

1525

if(ret >= 1){

1526

/* Pick the first good interface */

1527

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

1528

if(debug){

1529

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

1530

}

1531

if(interface == NULL){

1532

perror_plus("malloc");

1533

free(direntries);

1534

exitcode = EXIT_FAILURE;

1535

goto end;

1536

}

1537

free(direntries);

1538

} else {

1539

free(direntries);

1540

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

941

1541

exitcode = EXIT_FAILURE;

942

1542

goto end;

943

1543

}

944

1544

}

945

1545

1546

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

1547

from the signal handler */

1548

/* Initialize the pseudo-RNG for Avahi */

1549

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

1550

mc.simple_poll = avahi_simple_poll_new();

1551

if(mc.simple_poll == NULL){

1552

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

1553

exitcode = EX_UNAVAILABLE;

1554

goto end;

1555

}

1556

1557

sigemptyset(&sigterm_action.sa_mask);

1558

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

1559

if(ret == -1){

1560

perror_plus("sigaddset");

1561

exitcode = EX_OSERR;

1562

goto end;

1563

}

1564

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

1565

if(ret == -1){

1566

perror_plus("sigaddset");

1567

exitcode = EX_OSERR;

1568

goto end;

1569

}

1570

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

1571

if(ret == -1){

1572

perror_plus("sigaddset");

1573

exitcode = EX_OSERR;

1574

goto end;

1575

}

1576

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

1577

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

1578

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

1579

*/

1580

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

1581

if(ret == -1){

1582

perror_plus("sigaction");

1583

return EX_OSERR;

1584

}

1585

if(old_sigterm_action.sa_handler != SIG_IGN){

1586

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

1587

if(ret == -1){

1588

perror_plus("sigaction");

1589

exitcode = EX_OSERR;

1590

goto end;

1591

}

1592

}

1593

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

1594

if(ret == -1){

1595

perror_plus("sigaction");

1596

return EX_OSERR;

1597

}

1598

if(old_sigterm_action.sa_handler != SIG_IGN){

1599

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

1600

if(ret == -1){

1601

perror_plus("sigaction");

1602

exitcode = EX_OSERR;

1603

goto end;

1604

}

1605

}

1606

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

1607

if(ret == -1){

1608

perror_plus("sigaction");

1609

return EX_OSERR;

1610

}

1611

if(old_sigterm_action.sa_handler != SIG_IGN){

1612

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

1613

if(ret == -1){

1614

perror_plus("sigaction");

1615

exitcode = EX_OSERR;

1616

goto end;

1617

}

1618

}

1619

946

1620

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

947

{

1621

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

1622

if_index = (AvahiIfIndex) if_nametoindex(interface);

1623

if(if_index == 0){

1624

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

1625

exitcode = EX_UNAVAILABLE;

1626

goto end;

1627

}

1628

1629

if(quit_now){

1630

goto end;

1631

}

1632

1633

/* Re-raise priviliges */

1634

errno = 0;

1635

ret = seteuid(0);

1636

if(ret == -1){

1637

perror_plus("seteuid");

1638

}

1639

948

1640

#ifdef __linux__

949

1641

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

950

messages to mess up the prompt */

1642

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

951

1643

ret = klogctl(8, NULL, 5);

1644

bool restore_loglevel = true;

952

1645

if(ret == -1){

953

perror("klogctl");

1646

restore_loglevel = false;

1647

perror_plus("klogctl");

954

1648

}

955

#endif

1649

#endif /* __linux__ */

956

1650

957

1651

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

958

1652

if(sd < 0){

959

perror("socket");

960

exitcode = EXIT_FAILURE;

1653

perror_plus("socket");

1654

exitcode = EX_OSERR;

961

1655

#ifdef __linux__

962

ret = klogctl(7, NULL, 0);

1656

if(restore_loglevel){

1657

ret = klogctl(7, NULL, 0);

1658

if(ret == -1){

1659

perror_plus("klogctl");

1660

}

1661

}

1662

#endif /* __linux__ */

1663

/* Lower privileges */

1664

errno = 0;

1665

ret = seteuid(uid);

963

1666

if(ret == -1){

964

perror("klogctl");

1667

perror_plus("seteuid");

965

1668

}

966

#endif

967

1669

goto end;

968

1670

}

969

1671

strcpy(network.ifr_name, interface);

970

1672

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

971

1673

if(ret == -1){

972

perror("ioctl SIOCGIFFLAGS");

1674

perror_plus("ioctl SIOCGIFFLAGS");

973

1675

#ifdef __linux__

974

ret = klogctl(7, NULL, 0);

1676

if(restore_loglevel){

1677

ret = klogctl(7, NULL, 0);

1678

if(ret == -1){

1679

perror_plus("klogctl");

1680

}

1681

}

1682

#endif /* __linux__ */

1683

exitcode = EX_OSERR;

1684

/* Lower privileges */

1685

errno = 0;

1686

ret = seteuid(uid);

975

1687

if(ret == -1){

976

perror("klogctl");

1688

perror_plus("seteuid");

977

1689

}

978

#endif

979

exitcode = EXIT_FAILURE;

980

1690

goto end;

981

1691

}

982

1692

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

983

1693

network.ifr_flags |= IFF_UP;

1694

take_down_interface = true;

984

1695

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

985

1696

if(ret == -1){

986

perror("ioctl SIOCSIFFLAGS");

987

exitcode = EXIT_FAILURE;

1697

take_down_interface = false;

1698

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1699

exitcode = EX_OSERR;

988

1700

#ifdef __linux__

989

ret = klogctl(7, NULL, 0);

1701

if(restore_loglevel){

1702

ret = klogctl(7, NULL, 0);

1703

if(ret == -1){

1704

perror_plus("klogctl");

1705

}

1706

}

1707

#endif /* __linux__ */

1708

/* Lower privileges */

1709

errno = 0;

1710

ret = seteuid(uid);

990

1711

if(ret == -1){

991

perror("klogctl");

1712

perror_plus("seteuid");

992

1713

}

993

#endif

994

1714

goto end;

995

1715

}

996

1716

}

997

/* sleep checking until interface is running */

1717

/* Sleep checking until interface is running.

1718

Check every 0.25s, up to total time of delay */

998

1719

for(int i=0; i < delay * 4; i++){

999

1720

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

1000

1721

if(ret == -1){

1001

perror("ioctl SIOCGIFFLAGS");

1722

perror_plus("ioctl SIOCGIFFLAGS");

1002

1723

} else if(network.ifr_flags & IFF_RUNNING){

1003

1724

break;

1004

1725

}

1005

1726

struct timespec sleeptime = { .tv_nsec = 250000000 };

1006

1727

ret = nanosleep(&sleeptime, NULL);

1007

1728

if(ret == -1 and errno != EINTR){

1008

perror("nanosleep");

1729

perror_plus("nanosleep");

1009

1730

}

1010

1731

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1732

if(not take_down_interface){

1733

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

1734

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

1735

if(ret == -1){

1736

perror_plus("close");

1737

}

1014

1738

}

1015

1739

#ifdef __linux__

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);

1740

if(restore_loglevel){

1741

/* Restores kernel loglevel to default */

1742

ret = klogctl(7, NULL, 0);

1743

if(ret == -1){

1744

perror_plus("klogctl");

1745

}

1746

}

1747

#endif /* __linux__ */

1748

/* Lower privileges */

1749

errno = 0;

1750

if(take_down_interface){

1751

/* Lower privileges */

1752

ret = seteuid(uid);

1753

if(ret == -1){

1754

perror_plus("seteuid");

1755

}

1756

} else {

1757

/* Lower privileges permanently */

1758

ret = setuid(uid);

1759

if(ret == -1){

1760

perror_plus("setuid");

1761

}

1762

}

1763

}

1764

1765

if(quit_now){

1766

goto end;

1767

}

1768

1769

ret = init_gnutls_global(pubkey, seckey);

1038

1770

if(ret == -1){

1039

1771

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

1040

exitcode = EXIT_FAILURE;

1772

exitcode = EX_UNAVAILABLE;

1041

1773

goto end;

1042

1774

} else {

1043

1775

gnutls_initialized = true;

1044

1776

}

1045

1777

1778

if(quit_now){

1779

goto end;

1780

}

1781

1046

1782

if(mkdtemp(tempdir) == NULL){

1047

perror("mkdtemp");

1783

perror_plus("mkdtemp");

1048

1784

goto end;

1049

1785

}

1050

1786

tempdir_created = true;

1051

1787

1052

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

1788

if(quit_now){

1789

goto end;

1790

}

1791

1792

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

1053

1793

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

1054

exitcode = EXIT_FAILURE;

1794

exitcode = EX_UNAVAILABLE;

1055

1795

goto end;

1056

1796

} else {

1057

1797

gpgme_initialized = true;

1058

1798

}

1059

1799

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;

1800

if(quit_now){

1064

1801

goto end;

1065

1802

}

1066

1803

1070

1807

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

1071

1808

if(address == NULL){

1072

1809

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

1073

exitcode = EXIT_FAILURE;

1074

goto end;

1075

}

1810

exitcode = EX_USAGE;

1811

goto end;

1812

}

1813

1814

if(quit_now){

1815

goto end;

1816

}

1817

1076

1818

uint16_t port;

1077

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

1078

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

1079

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

1819

errno = 0;

1820

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

1821

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

1822

or tmpmax != (uint16_t)tmpmax){

1080

1823

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

1081

exitcode = EXIT_FAILURE;

1082

goto end;

1083

}

1824

exitcode = EX_USAGE;

1825

goto end;

1826

}

1827

1828

if(quit_now){

1829

goto end;

1830

}

1831

1084

1832

port = (uint16_t)tmpmax;

1085

1833

*address = '\0';

1834

/* Colon in address indicates IPv6 */

1835

int af;

1836

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

1837

af = AF_INET6;

1838

/* Accept [] around IPv6 address - see RFC 5952 */

1839

if(connect_to[0] == '[' and address[-1] == ']')

1840

{

1841

connect_to++;

1842

address[-1] = '\0';

1843

}

1844

} else {

1845

af = AF_INET;

1846

}

1086

1847

address = connect_to;

1087

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

1088

if(ret < 0){

1089

exitcode = EXIT_FAILURE;

1090

} else {

1848

1849

if(quit_now){

1850

goto end;

1851

}

1852

1853

while(not quit_now){

1854

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

1855

if(quit_now or ret == 0){

1856

break;

1857

}

1858

if(debug){

1859

fprintf(stderr, "Retrying in %d seconds\n",

1860

(int)retry_interval);

1861

}

1862

sleep((int)retry_interval);

1863

};

1864

1865

if (not quit_now){

1091

1866

exitcode = EXIT_SUCCESS;

1092

1867

}

1868

1093

1869

goto end;

1094

1870

}

1095

1871

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;

1872

if(quit_now){

1108

1873

goto end;

1109

1874

}

1110

1875

1130

1895

if(mc.server == NULL){

1131

1896

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

1132

1897

avahi_strerror(error));

1133

exitcode = EXIT_FAILURE;

1898

exitcode = EX_UNAVAILABLE;

1899

goto end;

1900

}

1901

1902

if(quit_now){

1134

1903

goto end;

1135

1904

}

1136

1905

1137

1906

/* Create the Avahi service browser */

1138

1907

sb = avahi_s_service_browser_new(mc.server, if_index,

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1908

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1909

NULL, 0, browse_callback, NULL);

1141

1910

if(sb == NULL){

1142

1911

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

1143

1912

avahi_strerror(avahi_server_errno(mc.server)));

1144

exitcode = EXIT_FAILURE;

1913

exitcode = EX_UNAVAILABLE;

1914

goto end;

1915

}

1916

1917

if(quit_now){

1145

1918

goto end;

1146

1919

}

1147

1920

1150

1923

if(debug){

1151

1924

fprintf(stderr, "Starting Avahi loop search\n");

1152

1925

}

1153

1154

avahi_simple_poll_loop(mc.simple_poll);

1926

1927

ret = avahi_loop_with_timeout(mc.simple_poll,

1928

(int)(retry_interval * 1000));

1929

if(debug){

1930

fprintf(stderr, "avahi_loop_with_timeout exited %s\n",

1931

(ret == 0) ? "successfully" : "with error");

1932

}

1155

1933

1156

1934

end:

1157

1935

1178

1956

if(gpgme_initialized){

1179

1957

gpgme_release(mc.ctx);

1180

1958

}

1181

1182

/* Removes the temp directory used by GPGME */

1959

1960

/* Cleans up the circular linked list of Mandos servers the client

1961

has seen */

1962

if(mc.current_server != NULL){

1963

mc.current_server->prev->next = NULL;

1964

while(mc.current_server != NULL){

1965

server *next = mc.current_server->next;

1966

free(mc.current_server);

1967

mc.current_server = next;

1968

}

1969

}

1970

1971

/* Take down the network interface */

1972

if(take_down_interface){

1973

/* Re-raise priviliges */

1974

errno = 0;

1975

ret = seteuid(0);

1976

if(ret == -1){

1977

perror_plus("seteuid");

1978

}

1979

if(geteuid() == 0){

1980

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

1981

if(ret == -1){

1982

perror_plus("ioctl SIOCGIFFLAGS");

1983

} else if(network.ifr_flags & IFF_UP) {

1984

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

1985

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

1986

if(ret == -1){

1987

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1988

}

1989

}

1990

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

1991

if(ret == -1){

1992

perror_plus("close");

1993

}

1994

/* Lower privileges permanently */

1995

errno = 0;

1996

ret = setuid(uid);

1997

if(ret == -1){

1998

perror_plus("setuid");

1999

}

2000

}

2001

}

2002

2003

/* Removes the GPGME temp directory and all files inside */

1183

2004

if(tempdir_created){

1184

DIR *d;

1185

struct dirent *direntry;

1186

d = opendir(tempdir);

1187

if(d == NULL){

1188

if(errno != ENOENT){

1189

perror("opendir");

1190

}

1191

} else {

1192

while(true){

1193

direntry = readdir(d);

1194

if(direntry == NULL){

1195

break;

1196

}

1197

/* Skip "." and ".." */

1198

if(direntry->d_name[0] == '.'

1199

and (direntry->d_name[1] == '\0'

1200

or (direntry->d_name[1] == '.'

1201

and direntry->d_name[2] == '\0'))){

1202

continue;

1203

}

2005

struct dirent **direntries = NULL;

2006

struct dirent *direntry = NULL;

2007

ret = scandir(tempdir, &direntries, notdotentries, alphasort);

2008

if (ret > 0){

2009

for(int i = 0; i < ret; i++){

2010

direntry = direntries[i];

1204

2011

char *fullname = NULL;

1205

2012

ret = asprintf(&fullname, "%s/%s", tempdir,

1206

2013

direntry->d_name);

1207

2014

if(ret < 0){

1208

perror("asprintf");

2015

perror_plus("asprintf");

1209

2016

continue;

1210

2017

}

1211

2018

ret = remove(fullname);

1215

2022

}

1216

2023

free(fullname);

1217

2024

}

1218

closedir(d);

2025

}

2026

2027

/* need to be cleaned even if ret == 0 because man page doesn't

2028

specify */

2029

free(direntries);

2030

if (ret == -1){

2031

perror_plus("scandir");

1219

2032

}

1220

2033

ret = rmdir(tempdir);

1221

2034

if(ret == -1 and errno != ENOENT){

1222

perror("rmdir");

1223

}

2035

perror_plus("rmdir");

2036

}

2037

}

2038

2039

if(quit_now){

2040

sigemptyset(&old_sigterm_action.sa_mask);

2041

old_sigterm_action.sa_handler = SIG_DFL;

2042

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

2043

&old_sigterm_action,

2044

NULL));

2045

if(ret == -1){

2046

perror_plus("sigaction");

2047

}

2048

do {

2049

ret = raise(signal_received);

2050

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

2051

if(ret != 0){

2052

perror_plus("raise");

2053

abort();

2054

}

2055

TEMP_FAILURE_RETRY(pause());

1224

2056

}

1225

2057

1226

2058

return exitcode;