/mandos/release : revision 237.7.35

9

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

10

*

11

* Everything else is

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13

12

13

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*

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 */

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45

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

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

44

srand() */

45

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

46

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

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strtof(), abort() */

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

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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,

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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,

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struct in6_addr, inet_pton(),

57

connect() */

58

inet_pton(), connect() */

58

59

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

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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(),

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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

75

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(),

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sigaction(), SIGTERM, sig_atomic_t,

85

raise() */

86

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

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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",

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.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

int add_server(const char *ip, uint16_t port,

191

AvahiIfIndex if_index,

192

int af){

193

int ret;

194

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

195

if(new_server == NULL){

196

perror_plus("malloc");

197

return -1;

198

}

199

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

200

.port = port,

201

.if_index = if_index,

202

.af = af };

203

if(new_server->ip == NULL){

204

perror_plus("strdup");

205

return -1;

206

}

207

/* unique case of first server */

208

if (mc.current_server == NULL){

209

new_server->next = new_server;

210

new_server->prev = new_server;

211

mc.current_server = new_server;

212

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

213

} else {

214

new_server->next = mc.current_server;

215

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

216

new_server->prev->next = new_server;

217

mc.current_server->prev = new_server;

218

}

219

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

220

if(ret == -1){

221

perror_plus("clock_gettime");

222

return -1;

223

}

224

return 0;

225

}

226

149

227

/*

150

228

* Initialize GPGME.

151

229

*/

152

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

230

static bool init_gpgme(const char *seckey,

153

231

const char *pubkey, const char *tempdir){

154

int ret;

155

232

gpgme_error_t rc;

156

233

gpgme_engine_info_t engine_info;

157

234

160

237

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

161

238

*/

162

239

bool import_key(const char *filename){

240

int ret;

163

241

int fd;

164

242

gpgme_data_t pgp_data;

165

243

166

244

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

167

245

if(fd == -1){

168

perror("open");

246

perror_plus("open");

169

247

return false;

170

248

}

171

249

176

254

return false;

177

255

}

178

256

179

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

257

rc = gpgme_op_import(mc.ctx, pgp_data);

180

258

if(rc != GPG_ERR_NO_ERROR){

181

259

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

182

260

gpgme_strsource(rc), gpgme_strerror(rc));

185

263

186

264

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

187

265

if(ret == -1){

188

perror("close");

266

perror_plus("close");

189

267

}

190

268

gpgme_data_release(pgp_data);

191

269

return true;

192

270

}

193

271

194

272

if(debug){

195

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

273

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

196

274

}

197

275

198

276

/* Init GPGME */

225

303

}

226

304

227

305

/* Create new GPGME "context" */

228

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

306

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

229

307

if(rc != GPG_ERR_NO_ERROR){

230

308

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

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309

gpgme_strsource(rc), gpgme_strerror(rc));

236

314

return false;

237

315

}

238

316

239

return true;

317

return true;

240

318

}

241

319

242

320

/*

243

321

* Decrypt OpenPGP data.

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322

* Returns -1 on error

245

323

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

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const char *cryptotext,

324

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

325

size_t crypto_size,

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326

char **plaintext){

250

327

gpgme_data_t dh_crypto, dh_plain;

277

354

278

355

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

279

356

data buffer */

280

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

357

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

281

358

if(rc != GPG_ERR_NO_ERROR){

282

359

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

283

360

gpgme_strsource(rc), gpgme_strerror(rc));

284

361

plaintext_length = -1;

285

362

if(debug){

286

363

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

364

result = gpgme_op_decrypt_result(mc.ctx);

288

365

if(result == NULL){

289

366

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

290

367

} else {

297

374

}

298

375

gpgme_recipient_t recipient;

299

376

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

}

377

while(recipient != NULL){

378

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

379

gpgme_pubkey_algo_name(recipient->pubkey_algo));

380

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

381

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

382

recipient->status == GPG_ERR_NO_SECKEY

383

? "No" : "Yes");

384

recipient = recipient->next;

310

385

}

311

386

}

312

387

}

319

394

320

395

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

321

396

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

322

perror("gpgme_data_seek");

397

perror_plus("gpgme_data_seek");

323

398

plaintext_length = -1;

324

399

goto decrypt_end;

325

400

}

326

401

327

402

*plaintext = NULL;

328

403

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

404

plaintext_capacity = incbuffer(plaintext,

330

405

(size_t)plaintext_length,

331

406

plaintext_capacity);

332

407

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

408

perror_plus("incbuffer");

334

409

plaintext_length = -1;

335

410

goto decrypt_end;

336

411

}

343

418

break;

344

419

}

345

420

if(ret < 0){

346

perror("gpgme_data_read");

421

perror_plus("gpgme_data_read");

347

422

plaintext_length = -1;

348

423

goto decrypt_end;

349

424

}

382

457

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

383

458

}

384

459

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

460

static int init_gnutls_global(const char *pubkeyfilename,

387

461

const char *seckeyfilename){

388

462

int ret;

389

463

407

481

}

408

482

409

483

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

484

ret = gnutls_certificate_allocate_credentials(&mc.cred);

411

485

if(ret != GNUTLS_E_SUCCESS){

412

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

413

* from

414

* -Wunreachable-code

415

*/

486

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

416

487

safer_gnutls_strerror(ret));

417

488

gnutls_global_deinit();

418

489

return -1;

425

496

}

426

497

427

498

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

499

(mc.cred, pubkeyfilename, seckeyfilename,

429

500

GNUTLS_OPENPGP_FMT_BASE64);

430

501

if(ret != GNUTLS_E_SUCCESS){

431

502

fprintf(stderr,

437

508

}

438

509

439

510

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

511

ret = gnutls_dh_params_init(&mc.dh_params);

441

512

if(ret != GNUTLS_E_SUCCESS){

442

513

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

443

514

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

444

515

goto globalfail;

445

516

}

446

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

517

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

447

518

if(ret != GNUTLS_E_SUCCESS){

448

519

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

449

520

safer_gnutls_strerror(ret));

450

521

goto globalfail;

451

522

}

452

523

453

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

524

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

525

455

526

return 0;

456

527

457

528

globalfail:

458

529

459

gnutls_certificate_free_credentials(mc->cred);

530

gnutls_certificate_free_credentials(mc.cred);

460

531

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

532

gnutls_dh_params_deinit(mc.dh_params);

462

533

return -1;

463

534

}

464

535

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

536

static int init_gnutls_session(gnutls_session_t *session){

467

537

int ret;

468

538

/* GnuTLS session creation */

469

ret = gnutls_init(session, GNUTLS_SERVER);

539

do {

540

ret = gnutls_init(session, GNUTLS_SERVER);

541

if(quit_now){

542

return -1;

543

}

544

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

470

545

if(ret != GNUTLS_E_SUCCESS){

471

546

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

472

547

safer_gnutls_strerror(ret));

474

549

475

550

{

476

551

const char *err;

477

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

552

do {

553

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

554

if(quit_now){

555

gnutls_deinit(*session);

556

return -1;

557

}

558

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

478

559

if(ret != GNUTLS_E_SUCCESS){

479

560

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

480

561

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

484

565

}

485

566

}

486

567

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

568

do {

569

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

570

mc.cred);

571

if(quit_now){

572

gnutls_deinit(*session);

573

return -1;

574

}

575

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

489

576

if(ret != GNUTLS_E_SUCCESS){

490

577

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

491

578

safer_gnutls_strerror(ret));

494

581

}

495

582

496

583

/* ignore client certificate if any. */

497

gnutls_certificate_server_set_request(*session,

498

GNUTLS_CERT_IGNORE);

584

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

499

585

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

586

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

587

502

588

return 0;

503

589

}

509

595

/* Called when a Mandos server is found */

510

596

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

511

597

AvahiIfIndex if_index,

512

mandos_context *mc){

513

int ret, tcp_sd;

598

int af){

599

int ret, tcp_sd = -1;

514

600

ssize_t sret;

515

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

601

union {

602

struct sockaddr_in in;

603

struct sockaddr_in6 in6;

604

} to;

516

605

char *buffer = NULL;

517

char *decrypted_buffer;

606

char *decrypted_buffer = NULL;

518

607

size_t buffer_length = 0;

519

608

size_t buffer_capacity = 0;

520

ssize_t decrypted_buffer_size;

521

609

size_t written;

522

int retval = 0;

523

char interface[IF_NAMESIZE];

610

int retval = -1;

524

611

gnutls_session_t session;

525

526

ret = init_gnutls_session(mc, &session);

612

int pf; /* Protocol family */

613

614

errno = 0;

615

616

if(quit_now){

617

errno = EINTR;

618

return -1;

619

}

620

621

switch(af){

622

case AF_INET6:

623

pf = PF_INET6;

624

break;

625

case AF_INET:

626

pf = PF_INET;

627

break;

628

default:

629

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

630

errno = EINVAL;

631

return -1;

632

}

633

634

ret = init_gnutls_session(&session);

527

635

if(ret != 0){

528

636

return -1;

529

637

}

530

638

531

639

if(debug){

532

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

640

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

533

641

"\n", ip, port);

534

642

}

535

643

536

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

644

tcp_sd = socket(pf, SOCK_STREAM, 0);

537

645

if(tcp_sd < 0){

538

perror("socket");

539

return -1;

646

int e = errno;

647

perror_plus("socket");

648

errno = e;

649

goto mandos_end;

540

650

}

541

651

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);

652

if(quit_now){

653

errno = EINTR;

654

goto mandos_end;

548

655

}

549

656

550

657

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);

658

if(af == AF_INET6){

659

to.in6.sin6_family = (sa_family_t)af;

660

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

661

} else { /* IPv4 */

662

to.in.sin_family = (sa_family_t)af;

663

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

664

}

555

665

if(ret < 0 ){

556

perror("inet_pton");

557

return -1;

666

int e = errno;

667

perror_plus("inet_pton");

668

errno = e;

669

goto mandos_end;

558

670

}

559

671

if(ret == 0){

672

int e = errno;

560

673

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

561

return -1;

674

errno = e;

675

goto mandos_end;

562

676

}

563

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

677

if(af == AF_INET6){

678

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

679

-Wconversion and

680

-Wunreachable-code */

681

682

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

683

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

684

-Wunreachable-code*/

685

if(if_index == AVAHI_IF_UNSPEC){

686

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

687

" without a network interface\n");

688

errno = EINVAL;

689

goto mandos_end;

690

}

691

/* Set the network interface number as scope */

692

to.in6.sin6_scope_id = (uint32_t)if_index;

693

}

694

} else {

695

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

564

696

-Wconversion and

565

697

-Wunreachable-code */

698

}

566

699

567

to.in6.sin6_scope_id = (uint32_t)if_index;

700

if(quit_now){

701

errno = EINTR;

702

goto mandos_end;

703

}

568

704

569

705

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");

706

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

707

char interface[IF_NAMESIZE];

708

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

709

perror_plus("if_indextoname");

710

} else {

711

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

712

ip, interface, port);

713

}

714

} else {

715

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

716

port);

717

}

718

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

719

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

720

const char *pcret;

721

if(af == AF_INET6){

722

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

723

sizeof(addrstr));

724

} else {

725

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

726

sizeof(addrstr));

727

}

728

if(pcret == NULL){

729

perror_plus("inet_ntop");

576

730

} else {

577

731

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

578

732

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

580

734

}

581

735

}

582

736

583

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

737

if(quit_now){

738

errno = EINTR;

739

goto mandos_end;

740

}

741

742

if(af == AF_INET6){

743

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

744

} else {

745

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

746

}

584

747

if(ret < 0){

585

perror("connect");

586

return -1;

748

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

749

int e = errno;

750

perror_plus("connect");

751

errno = e;

752

}

753

goto mandos_end;

754

}

755

756

if(quit_now){

757

errno = EINTR;

758

goto mandos_end;

587

759

}

588

760

589

761

const char *out = mandos_protocol_version;

593

765

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

594

766

out_size - written));

595

767

if(ret == -1){

596

perror("write");

597

retval = -1;

768

int e = errno;

769

perror_plus("write");

770

errno = e;

598

771

goto mandos_end;

599

772

}

600

773

written += (size_t)ret;

608

781

break;

609

782

}

610

783

}

784

785

if(quit_now){

786

errno = EINTR;

787

goto mandos_end;

788

}

611

789

}

612

790

613

791

if(debug){

614

792

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

615

793

}

616

794

795

if(quit_now){

796

errno = EINTR;

797

goto mandos_end;

798

}

799

800

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

617

801

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

618

802

619

do{

803

if(quit_now){

804

errno = EINTR;

805

goto mandos_end;

806

}

807

808

do {

620

809

ret = gnutls_handshake(session);

810

if(quit_now){

811

errno = EINTR;

812

goto mandos_end;

813

}

621

814

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

622

815

623

816

if(ret != GNUTLS_E_SUCCESS){

625

818

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

626

819

gnutls_perror(ret);

627

820

}

628

retval = -1;

821

errno = EPROTO;

629

822

goto mandos_end;

630

823

}

631

824

632

825

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

633

826

634

827

if(debug){

635

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

828

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

636

829

ip);

637

830

}

638

831

639

832

while(true){

640

buffer_capacity = adjustbuffer(&buffer, buffer_length,

833

834

if(quit_now){

835

errno = EINTR;

836

goto mandos_end;

837

}

838

839

buffer_capacity = incbuffer(&buffer, buffer_length,

641

840

buffer_capacity);

642

841

if(buffer_capacity == 0){

643

perror("adjustbuffer");

644

retval = -1;

842

int e = errno;

843

perror_plus("incbuffer");

844

errno = e;

845

goto mandos_end;

846

}

847

848

if(quit_now){

849

errno = EINTR;

645

850

goto mandos_end;

646

851

}

647

852

656

861

case GNUTLS_E_AGAIN:

657

862

break;

658

863

case GNUTLS_E_REHANDSHAKE:

659

do{

864

do {

660

865

ret = gnutls_handshake(session);

866

867

if(quit_now){

868

errno = EINTR;

869

goto mandos_end;

870

}

661

871

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

662

872

if(ret < 0){

663

873

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

664

874

gnutls_perror(ret);

665

retval = -1;

875

errno = EPROTO;

666

876

goto mandos_end;

667

877

}

668

878

break;

669

879

default:

670

880

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

671

881

" encrypted session with Mandos server\n");

672

retval = -1;

673

882

gnutls_bye(session, GNUTLS_SHUT_RDWR);

883

errno = EIO;

674

884

goto mandos_end;

675

885

}

676

886

} else {

682

892

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

683

893

}

684

894

685

gnutls_bye(session, GNUTLS_SHUT_RDWR);

895

if(quit_now){

896

errno = EINTR;

897

goto mandos_end;

898

}

899

900

do {

901

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

902

if(quit_now){

903

errno = EINTR;

904

goto mandos_end;

905

}

906

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

686

907

687

908

if(buffer_length > 0){

688

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

909

ssize_t decrypted_buffer_size;

910

decrypted_buffer_size = pgp_packet_decrypt(buffer,

689

911

buffer_length,

690

912

&decrypted_buffer);

691

913

if(decrypted_buffer_size >= 0){

914

692

915

written = 0;

693

916

while(written < (size_t) decrypted_buffer_size){

917

if(quit_now){

918

errno = EINTR;

919

goto mandos_end;

920

}

921

694

922

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

695

923

(size_t)decrypted_buffer_size - written,

696

924

stdout);

697

925

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

926

int e = errno;

698

927

if(debug){

699

928

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

700

929

strerror(errno));

701

930

}

702

retval = -1;

703

break;

931

errno = e;

932

goto mandos_end;

704

933

}

705

934

written += (size_t)ret;

706

935

}

707

free(decrypted_buffer);

708

} else {

709

retval = -1;

936

retval = 0;

710

937

}

711

} else {

712

retval = -1;

713

938

}

714

939

715

940

/* Shutdown procedure */

716

941

717

942

mandos_end:

718

free(buffer);

719

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

720

if(ret == -1){

721

perror("close");

943

{

944

int e = errno;

945

free(decrypted_buffer);

946

free(buffer);

947

if(tcp_sd >= 0){

948

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

949

}

950

if(ret == -1){

951

if(e == 0){

952

e = errno;

953

}

954

perror_plus("close");

955

}

956

gnutls_deinit(session);

957

errno = e;

958

if(quit_now){

959

errno = EINTR;

960

retval = -1;

961

}

722

962

}

723

gnutls_deinit(session);

724

963

return retval;

725

964

}

726

965

727

966

static void resolve_callback(AvahiSServiceResolver *r,

728

967

AvahiIfIndex interface,

729

AVAHI_GCC_UNUSED AvahiProtocol protocol,

968

AvahiProtocol proto,

730

969

AvahiResolverEvent event,

731

970

const char *name,

732

971

const char *type,

737

976

AVAHI_GCC_UNUSED AvahiStringList *txt,

738

977

AVAHI_GCC_UNUSED AvahiLookupResultFlags

739

978

flags,

740

void* userdata){

741

mandos_context *mc = userdata;

979

AVAHI_GCC_UNUSED void* userdata){

742

980

assert(r);

743

981

744

982

/* Called whenever a service has been resolved successfully or

745

983

timed out */

746

984

985

if(quit_now){

986

return;

987

}

988

747

989

switch(event){

748

990

default:

749

991

case AVAHI_RESOLVER_FAILURE:

750

992

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

751

993

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

752

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

994

avahi_strerror(avahi_server_errno(mc.server)));

753

995

break;

754

996

755

997

case AVAHI_RESOLVER_FOUND:

761

1003

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

762

1004

ip, (intmax_t)interface, port);

763

1005

}

764

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

1006

int ret = start_mandos_communication(ip, port, interface,

1007

avahi_proto_to_af(proto));

765

1008

if(ret == 0){

766

avahi_simple_poll_quit(mc->simple_poll);

1009

avahi_simple_poll_quit(mc.simple_poll);

1010

} else {

1011

ret = add_server(ip, port, interface,

1012

avahi_proto_to_af(proto));

767

1013

}

768

1014

}

769

1015

}

779

1025

const char *domain,

780

1026

AVAHI_GCC_UNUSED AvahiLookupResultFlags

781

1027

flags,

782

void* userdata){

783

mandos_context *mc = userdata;

1028

AVAHI_GCC_UNUSED void* userdata){

784

1029

assert(b);

785

1030

786

1031

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

787

1032

is removed from the LAN */

788

1033

1034

if(quit_now){

1035

return;

1036

}

1037

789

1038

switch(event){

790

1039

default:

791

1040

case AVAHI_BROWSER_FAILURE:

792

1041

793

1042

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

794

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

795

avahi_simple_poll_quit(mc->simple_poll);

1043

avahi_strerror(avahi_server_errno(mc.server)));

1044

avahi_simple_poll_quit(mc.simple_poll);

796

1045

return;

797

1046

798

1047

case AVAHI_BROWSER_NEW:

801

1050

the callback function is called the Avahi server will free the

802

1051

resolver for us. */

803

1052

804

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

805

protocol, name, type, domain,

806

AVAHI_PROTO_INET6, 0,

807

resolve_callback, mc)))

1053

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

1054

name, type, domain, protocol, 0,

1055

resolve_callback, NULL) == NULL)

808

1056

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

809

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

1057

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

810

1058

break;

811

1059

812

1060

case AVAHI_BROWSER_REMOVE:

821

1069

}

822

1070

}

823

1071

1072

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

1073

static void handle_sigterm(int sig){

1074

if(quit_now){

1075

return;

1076

}

1077

quit_now = 1;

1078

signal_received = sig;

1079

int old_errno = errno;

1080

/* set main loop to exit */

1081

if(mc.simple_poll != NULL){

1082

avahi_simple_poll_quit(mc.simple_poll);

1083

}

1084

errno = old_errno;

1085

}

1086

1087

/*

1088

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

1089

* corresponds to an acceptable network device.

1090

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

1091

*/

1092

int good_interface(const struct dirent *if_entry){

1093

ssize_t ssret;

1094

char *flagname = NULL;

1095

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

1096

return 0;

1097

}

1098

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

1099

if_entry->d_name);

1100

if(ret < 0){

1101

perror_plus("asprintf");

1102

return 0;

1103

}

1104

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

1105

if(flags_fd == -1){

1106

perror_plus("open");

1107

free(flagname);

1108

return 0;

1109

}

1110

free(flagname);

1111

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

1112

/* read line from flags_fd */

1113

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

1114

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

1115

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

1116

if(flagstring == NULL){

1117

perror_plus("malloc");

1118

close(flags_fd);

1119

return 0;

1120

}

1121

while(to_read > 0){

1122

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

1123

(size_t)to_read));

1124

if(ssret == -1){

1125

perror_plus("read");

1126

free(flagstring);

1127

close(flags_fd);

1128

return 0;

1129

}

1130

to_read -= ssret;

1131

if(ssret == 0){

1132

break;

1133

}

1134

}

1135

close(flags_fd);

1136

intmax_t tmpmax;

1137

char *tmp;

1138

errno = 0;

1139

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

1140

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

1141

and not (isspace(*tmp)))

1142

or tmpmax != (ifreq_flags)tmpmax){

1143

if(debug){

1144

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

1145

flagstring, if_entry->d_name);

1146

}

1147

free(flagstring);

1148

return 0;

1149

}

1150

free(flagstring);

1151

ifreq_flags flags = (ifreq_flags)tmpmax;

1152

/* Reject the loopback device */

1153

if(flags & IFF_LOOPBACK){

1154

if(debug){

1155

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

1156

if_entry->d_name);

1157

}

1158

return 0;

1159

}

1160

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

1161

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

1162

if(debug){

1163

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

1164

if_entry->d_name);

1165

}

1166

return 1;

1167

}

1168

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

1169

if(not (flags & IFF_BROADCAST)){

1170

if(debug){

1171

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

1172

if_entry->d_name);

1173

}

1174

return 0;

1175

}

1176

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

1177

if(flags & IFF_NOARP){

1178

if(debug){

1179

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

1180

if_entry->d_name);

1181

}

1182

return 0;

1183

}

1184

/* Accept this device */

1185

if(debug){

1186

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

1187

if_entry->d_name);

1188

}

1189

return 1;

1190

}

1191

1192

int notdotentries(const struct dirent *direntry){

1193

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

1194

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

1195

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

1196

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

1197

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

1198

return 0;

1199

}

1200

return 1;

1201

}

1202

1203

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1204

int ret;

1205

struct timespec now;

1206

struct timespec waited_time;

1207

intmax_t block_time;

1208

1209

while(true){

1210

if(mc.current_server == NULL){

1211

if (debug){

1212

fprintf(stderr,

1213

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

1214

}

1215

ret = avahi_simple_poll_iterate(s, -1);

1216

} else {

1217

if (debug){

1218

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

1219

" or wait\n");

1220

}

1221

/* the current time */

1222

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1223

if(ret == -1){

1224

perror_plus("clock_gettime");

1225

return -1;

1226

}

1227

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

1228

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

1229

waited_time.tv_sec = (now.tv_sec

1230

- mc.current_server->last_seen.tv_sec);

1231

waited_time.tv_nsec = (now.tv_nsec

1232

- mc.current_server->last_seen.tv_nsec);

1233

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

1234

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

1235

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

1236

block_time = ((retry_interval

1237

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

1238

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

1239

1240

if (debug){

1241

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

1242

}

1243

1244

if(block_time <= 0){

1245

ret = start_mandos_communication(mc.current_server->ip,

1246

mc.current_server->port,

1247

mc.current_server->if_index,

1248

mc.current_server->af);

1249

if(ret == 0){

1250

avahi_simple_poll_quit(mc.simple_poll);

1251

return 0;

1252

}

1253

ret = clock_gettime(CLOCK_MONOTONIC,

1254

&mc.current_server->last_seen);

1255

if(ret == -1){

1256

perror_plus("clock_gettime");

1257

return -1;

1258

}

1259

mc.current_server = mc.current_server->next;

1260

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

1261

servers, but don't block */

1262

}

1263

1264

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

1265

}

1266

if(ret != 0){

1267

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

1268

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

1269

}

1270

}

1271

}

1272

}

1273

824

1274

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

825

1275

AvahiSServiceBrowser *sb = NULL;

826

1276

int error;

827

1277

int ret;

828

1278

intmax_t tmpmax;

829

int numchars;

1279

char *tmp;

830

1280

int exitcode = EXIT_SUCCESS;

831

const char *interface = "eth0";

1281

const char *interface = "";

832

1282

struct ifreq network;

833

int sd;

1283

int sd = -1;

1284

bool take_down_interface = false;

834

1285

uid_t uid;

835

1286

gid_t gid;

836

char *connect_to = NULL;

837

1287

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

838

1288

bool tempdir_created = false;

839

1289

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

840

1290

const char *seckey = PATHDIR "/" SECKEY;

841

1291

const char *pubkey = PATHDIR "/" PUBKEY;

842

1292

843

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

844

.dh_bits = 1024, .priority = "SECURE256"

845

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

846

1293

bool gnutls_initialized = false;

847

1294

bool gpgme_initialized = false;

848

double delay = 2.5;

1295

float delay = 2.5f;

1296

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

1297

retrying the same server again */

1298

1299

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1300

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1301

1302

uid = getuid();

1303

gid = getgid();

1304

1305

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

1306

errno = 0;

1307

ret = setgid(gid);

1308

if(ret == -1){

1309

perror_plus("setgid");

1310

}

1311

1312

/* Lower user privileges (temporarily) */

1313

errno = 0;

1314

ret = seteuid(uid);

1315

if(ret == -1){

1316

perror_plus("seteuid");

1317

}

1318

1319

if(quit_now){

1320

goto end;

1321

}

849

1322

850

1323

{

851

1324

struct argp_option options[] = {

857

1330

.group = 1 },

858

1331

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

859

1332

.arg = "NAME",

860

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

861

" servers",

1333

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

1334

" Mandos servers",

862

1335

.group = 1 },

863

1336

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

864

1337

.arg = "FILE",

881

1354

.arg = "SECONDS",

882

1355

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

883

1356

.group = 2 },

1357

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

1358

.arg = "SECONDS",

1359

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

1360

.group = 2 },

1361

/*

1362

* These reproduce what we would get without ARGP_NO_HELP

1363

*/

1364

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

1365

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

1366

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

1367

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

1368

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

1369

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

884

1370

{ .name = NULL }

885

1371

};

886

1372

887

1373

error_t parse_opt(int key, char *arg,

888

1374

struct argp_state *state){

1375

errno = 0;

889

1376

switch(key){

890

1377

case 128: /* --debug */

891

1378

debug = true;

903

1390

pubkey = arg;

904

1391

break;

905

1392

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);

1393

errno = 0;

1394

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

1395

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

1396

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

1397

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

911

1398

}

912

1399

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

913

1400

break;

915

1402

mc.priority = arg;

916

1403

break;

917

1404

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);

1405

errno = 0;

1406

delay = strtof(arg, &tmp);

1407

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

1408

argp_error(state, "Bad delay");

1409

}

1410

case 132: /* --retry */

1411

errno = 0;

1412

retry_interval = strtod(arg, &tmp);

1413

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

1414

or (retry_interval * 1000) > INT_MAX){

1415

argp_error(state, "Bad retry interval");

922

1416

}

923

1417

break;

924

case ARGP_KEY_ARG:

925

argp_usage(state);

926

case ARGP_KEY_END:

1418

/*

1419

* These reproduce what we would get without ARGP_NO_HELP

1420

*/

1421

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

1422

argp_state_help(state, state->out_stream,

1423

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1424

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1425

case -3: /* --usage */

1426

argp_state_help(state, state->out_stream,

1427

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1428

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

1429

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

1430

exit(argp_err_exit_status);

927

1431

break;

928

1432

default:

929

1433

return ARGP_ERR_UNKNOWN;

930

1434

}

931

return 0;

1435

return errno;

932

1436

}

933

1437

934

1438

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

935

1439

.args_doc = "",

936

1440

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

937

1441

" 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");

1442

ret = argp_parse(&argp, argc, argv,

1443

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1444

switch(ret){

1445

case 0:

1446

break;

1447

case ENOMEM:

1448

default:

1449

errno = ret;

1450

perror_plus("argp_parse");

1451

exitcode = EX_OSERR;

1452

goto end;

1453

case EINVAL:

1454

exitcode = EX_USAGE;

1455

goto end;

1456

}

1457

}

1458

1459

{

1460

/* Work around Debian bug #633582:

1461

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

1462

struct stat st;

1463

1464

/* Re-raise priviliges */

1465

errno = 0;

1466

ret = seteuid(0);

1467

if(ret == -1){

1468

perror_plus("seteuid");

1469

}

1470

1471

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

1472

if(seckey_fd == -1){

1473

perror_plus("open");

1474

} else {

1475

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

1476

if(ret == -1){

1477

perror_plus("fstat");

1478

} else {

1479

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

1480

ret = fchown(seckey_fd, uid, gid);

1481

if(ret == -1){

1482

perror_plus("fchown");

1483

}

1484

}

1485

}

1486

TEMP_FAILURE_RETRY(close(seckey_fd));

1487

}

1488

1489

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

1490

if(pubkey_fd == -1){

1491

perror_plus("open");

1492

} else {

1493

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

1494

if(ret == -1){

1495

perror_plus("fstat");

1496

} else {

1497

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

1498

ret = fchown(pubkey_fd, uid, gid);

1499

if(ret == -1){

1500

perror_plus("fchown");

1501

}

1502

}

1503

}

1504

TEMP_FAILURE_RETRY(close(pubkey_fd));

1505

}

1506

1507

/* Lower privileges */

1508

errno = 0;

1509

ret = seteuid(uid);

1510

if(ret == -1){

1511

perror_plus("seteuid");

1512

}

1513

}

1514

1515

if(not debug){

1516

avahi_set_log_function(empty_log);

1517

}

1518

1519

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

1520

struct dirent **direntries;

1521

ret = scandir(sys_class_net, &direntries, good_interface,

1522

alphasort);

1523

if(ret >= 1){

1524

/* Pick the first good interface */

1525

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

1526

if(debug){

1527

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

1528

}

1529

if(interface == NULL){

1530

perror_plus("malloc");

1531

free(direntries);

1532

exitcode = EXIT_FAILURE;

1533

goto end;

1534

}

1535

free(direntries);

1536

} else {

1537

free(direntries);

1538

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

941

1539

exitcode = EXIT_FAILURE;

942

1540

goto end;

943

1541

}

944

1542

}

945

1543

1544

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

1545

from the signal handler */

1546

/* Initialize the pseudo-RNG for Avahi */

1547

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

1548

mc.simple_poll = avahi_simple_poll_new();

1549

if(mc.simple_poll == NULL){

1550

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

1551

exitcode = EX_UNAVAILABLE;

1552

goto end;

1553

}

1554

1555

sigemptyset(&sigterm_action.sa_mask);

1556

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

1557

if(ret == -1){

1558

perror_plus("sigaddset");

1559

exitcode = EX_OSERR;

1560

goto end;

1561

}

1562

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

1563

if(ret == -1){

1564

perror_plus("sigaddset");

1565

exitcode = EX_OSERR;

1566

goto end;

1567

}

1568

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

1569

if(ret == -1){

1570

perror_plus("sigaddset");

1571

exitcode = EX_OSERR;

1572

goto end;

1573

}

1574

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

1575

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

1576

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

1577

*/

1578

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

1579

if(ret == -1){

1580

perror_plus("sigaction");

1581

return EX_OSERR;

1582

}

1583

if(old_sigterm_action.sa_handler != SIG_IGN){

1584

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

1585

if(ret == -1){

1586

perror_plus("sigaction");

1587

exitcode = EX_OSERR;

1588

goto end;

1589

}

1590

}

1591

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

1592

if(ret == -1){

1593

perror_plus("sigaction");

1594

return EX_OSERR;

1595

}

1596

if(old_sigterm_action.sa_handler != SIG_IGN){

1597

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

1598

if(ret == -1){

1599

perror_plus("sigaction");

1600

exitcode = EX_OSERR;

1601

goto end;

1602

}

1603

}

1604

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

1605

if(ret == -1){

1606

perror_plus("sigaction");

1607

return EX_OSERR;

1608

}

1609

if(old_sigterm_action.sa_handler != SIG_IGN){

1610

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

1611

if(ret == -1){

1612

perror_plus("sigaction");

1613

exitcode = EX_OSERR;

1614

goto end;

1615

}

1616

}

1617

946

1618

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

947

{

1619

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

1620

if_index = (AvahiIfIndex) if_nametoindex(interface);

1621

if(if_index == 0){

1622

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

1623

exitcode = EX_UNAVAILABLE;

1624

goto end;

1625

}

1626

1627

if(quit_now){

1628

goto end;

1629

}

1630

1631

/* Re-raise priviliges */

1632

errno = 0;

1633

ret = seteuid(0);

1634

if(ret == -1){

1635

perror_plus("seteuid");

1636

}

1637

948

1638

#ifdef __linux__

949

1639

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

950

messages to mess up the prompt */

1640

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

951

1641

ret = klogctl(8, NULL, 5);

1642

bool restore_loglevel = true;

952

1643

if(ret == -1){

953

perror("klogctl");

1644

restore_loglevel = false;

1645

perror_plus("klogctl");

954

1646

}

955

#endif

1647

#endif /* __linux__ */

956

1648

957

1649

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

958

1650

if(sd < 0){

959

perror("socket");

960

exitcode = EXIT_FAILURE;

1651

perror_plus("socket");

1652

exitcode = EX_OSERR;

961

1653

#ifdef __linux__

962

ret = klogctl(7, NULL, 0);

1654

if(restore_loglevel){

1655

ret = klogctl(7, NULL, 0);

1656

if(ret == -1){

1657

perror_plus("klogctl");

1658

}

1659

}

1660

#endif /* __linux__ */

1661

/* Lower privileges */

1662

errno = 0;

1663

ret = seteuid(uid);

963

1664

if(ret == -1){

964

perror("klogctl");

1665

perror_plus("seteuid");

965

1666

}

966

#endif

967

1667

goto end;

968

1668

}

969

1669

strcpy(network.ifr_name, interface);

970

1670

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

971

1671

if(ret == -1){

972

perror("ioctl SIOCGIFFLAGS");

1672

perror_plus("ioctl SIOCGIFFLAGS");

973

1673

#ifdef __linux__

974

ret = klogctl(7, NULL, 0);

1674

if(restore_loglevel){

1675

ret = klogctl(7, NULL, 0);

1676

if(ret == -1){

1677

perror_plus("klogctl");

1678

}

1679

}

1680

#endif /* __linux__ */

1681

exitcode = EX_OSERR;

1682

/* Lower privileges */

1683

errno = 0;

1684

ret = seteuid(uid);

975

1685

if(ret == -1){

976

perror("klogctl");

1686

perror_plus("seteuid");

977

1687

}

978

#endif

979

exitcode = EXIT_FAILURE;

980

1688

goto end;

981

1689

}

982

1690

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

983

1691

network.ifr_flags |= IFF_UP;

1692

take_down_interface = true;

984

1693

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

985

1694

if(ret == -1){

986

perror("ioctl SIOCSIFFLAGS");

987

exitcode = EXIT_FAILURE;

1695

take_down_interface = false;

1696

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1697

exitcode = EX_OSERR;

988

1698

#ifdef __linux__

989

ret = klogctl(7, NULL, 0);

1699

if(restore_loglevel){

1700

ret = klogctl(7, NULL, 0);

1701

if(ret == -1){

1702

perror_plus("klogctl");

1703

}

1704

}

1705

#endif /* __linux__ */

1706

/* Lower privileges */

1707

errno = 0;

1708

ret = seteuid(uid);

990

1709

if(ret == -1){

991

perror("klogctl");

1710

perror_plus("seteuid");

992

1711

}

993

#endif

994

1712

goto end;

995

1713

}

996

1714

}

997

/* sleep checking until interface is running */

1715

/* Sleep checking until interface is running.

1716

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

998

1717

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

999

1718

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

1000

1719

if(ret == -1){

1001

perror("ioctl SIOCGIFFLAGS");

1720

perror_plus("ioctl SIOCGIFFLAGS");

1002

1721

} else if(network.ifr_flags & IFF_RUNNING){

1003

1722

break;

1004

1723

}

1005

1724

struct timespec sleeptime = { .tv_nsec = 250000000 };

1006

1725

ret = nanosleep(&sleeptime, NULL);

1007

1726

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

1008

perror("nanosleep");

1727

perror_plus("nanosleep");

1009

1728

}

1010

1729

}

1011

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

1012

if(ret == -1){

1013

perror("close");

1730

if(not take_down_interface){

1731

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

1732

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

1733

if(ret == -1){

1734

perror_plus("close");

1735

}

1014

1736

}

1015

1737

#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);

1738

if(restore_loglevel){

1739

/* Restores kernel loglevel to default */

1740

ret = klogctl(7, NULL, 0);

1741

if(ret == -1){

1742

perror_plus("klogctl");

1743

}

1744

}

1745

#endif /* __linux__ */

1746

/* Lower privileges */

1747

errno = 0;

1748

if(take_down_interface){

1749

/* Lower privileges */

1750

ret = seteuid(uid);

1751

if(ret == -1){

1752

perror_plus("seteuid");

1753

}

1754

} else {

1755

/* Lower privileges permanently */

1756

ret = setuid(uid);

1757

if(ret == -1){

1758

perror_plus("setuid");

1759

}

1760

}

1761

}

1762

1763

if(quit_now){

1764

goto end;

1765

}

1766

1767

ret = init_gnutls_global(pubkey, seckey);

1038

1768

if(ret == -1){

1039

1769

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

1040

exitcode = EXIT_FAILURE;

1770

exitcode = EX_UNAVAILABLE;

1041

1771

goto end;

1042

1772

} else {

1043

1773

gnutls_initialized = true;

1044

1774

}

1045

1775

1776

if(quit_now){

1777

goto end;

1778

}

1779

1046

1780

if(mkdtemp(tempdir) == NULL){

1047

perror("mkdtemp");

1781

perror_plus("mkdtemp");

1048

1782

goto end;

1049

1783

}

1050

1784

tempdir_created = true;

1051

1785

1052

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

1786

if(quit_now){

1787

goto end;

1788

}

1789

1790

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

1053

1791

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

1054

exitcode = EXIT_FAILURE;

1792

exitcode = EX_UNAVAILABLE;

1055

1793

goto end;

1056

1794

} else {

1057

1795

gpgme_initialized = true;

1058

1796

}

1059

1797

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;

1798

if(quit_now){

1064

1799

goto end;

1065

1800

}

1066

1801

1070

1805

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

1071

1806

if(address == NULL){

1072

1807

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

1073

exitcode = EXIT_FAILURE;

1074

goto end;

1075

}

1808

exitcode = EX_USAGE;

1809

goto end;

1810

}

1811

1812

if(quit_now){

1813

goto end;

1814

}

1815

1076

1816

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'){

1817

errno = 0;

1818

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

1819

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

1820

or tmpmax != (uint16_t)tmpmax){

1080

1821

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

1081

exitcode = EXIT_FAILURE;

1082

goto end;

1083

}

1822

exitcode = EX_USAGE;

1823

goto end;

1824

}

1825

1826

if(quit_now){

1827

goto end;

1828

}

1829

1084

1830

port = (uint16_t)tmpmax;

1085

1831

*address = '\0';

1086

1832

address = connect_to;

1087

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

1088

if(ret < 0){

1089

exitcode = EXIT_FAILURE;

1833

/* Colon in address indicates IPv6 */

1834

int af;

1835

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

1836

af = AF_INET6;

1090

1837

} else {

1838

af = AF_INET;

1839

}

1840

1841

if(quit_now){

1842

goto end;

1843

}

1844

1845

while(not quit_now){

1846

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

1847

if(quit_now or ret == 0){

1848

break;

1849

}

1850

sleep((int)retry_interval or 1);

1851

};

1852

1853

if (not quit_now){

1091

1854

exitcode = EXIT_SUCCESS;

1092

1855

}

1856

1093

1857

goto end;

1094

1858

}

1095

1859

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;

1860

if(quit_now){

1108

1861

goto end;

1109

1862

}

1110

1863

1130

1883

if(mc.server == NULL){

1131

1884

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

1132

1885

avahi_strerror(error));

1133

exitcode = EXIT_FAILURE;

1886

exitcode = EX_UNAVAILABLE;

1887

goto end;

1888

}

1889

1890

if(quit_now){

1134

1891

goto end;

1135

1892

}

1136

1893

1137

1894

/* Create the Avahi service browser */

1138

1895

sb = avahi_s_service_browser_new(mc.server, if_index,

1139

AVAHI_PROTO_INET6, "_mandos._tcp",

1140

NULL, 0, browse_callback, &mc);

1896

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1897

NULL, 0, browse_callback, NULL);

1141

1898

if(sb == NULL){

1142

1899

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

1143

1900

avahi_strerror(avahi_server_errno(mc.server)));

1144

exitcode = EXIT_FAILURE;

1901

exitcode = EX_UNAVAILABLE;

1902

goto end;

1903

}

1904

1905

if(quit_now){

1145

1906

goto end;

1146

1907

}

1147

1908

1150

1911

if(debug){

1151

1912

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

1152

1913

}

1153

1154

avahi_simple_poll_loop(mc.simple_poll);

1914

1915

ret = avahi_loop_with_timeout(mc.simple_poll,

1916

(int)(retry_interval * 1000));

1917

if(debug){

1918

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

1919

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

1920

}

1155

1921

1156

1922

end:

1157

1923

1178

1944

if(gpgme_initialized){

1179

1945

gpgme_release(mc.ctx);

1180

1946

}

1181

1182

/* Removes the temp directory used by GPGME */

1947

1948

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

1949

has seen */

1950

if(mc.current_server != NULL){

1951

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

1952

while(mc.current_server != NULL){

1953

server *next = mc.current_server->next;

1954

free(mc.current_server);

1955

mc.current_server = next;

1956

}

1957

}

1958

1959

/* Take down the network interface */

1960

if(take_down_interface){

1961

/* Re-raise priviliges */

1962

errno = 0;

1963

ret = seteuid(0);

1964

if(ret == -1){

1965

perror_plus("seteuid");

1966

}

1967

if(geteuid() == 0){

1968

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

1969

if(ret == -1){

1970

perror_plus("ioctl SIOCGIFFLAGS");

1971

} else if(network.ifr_flags & IFF_UP) {

1972

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

1973

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

1974

if(ret == -1){

1975

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1976

}

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("close");

1981

}

1982

/* Lower privileges permanently */

1983

errno = 0;

1984

ret = setuid(uid);

1985

if(ret == -1){

1986

perror_plus("setuid");

1987

}

1988

}

1989

}

1990

1991

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

1183

1992

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

}

1993

struct dirent **direntries = NULL;

1994

struct dirent *direntry = NULL;

1995

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

1996

if (ret > 0){

1997

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

1998

direntry = direntries[i];

1204

1999

char *fullname = NULL;

1205

2000

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

1206

2001

direntry->d_name);

1207

2002

if(ret < 0){

1208

perror("asprintf");

2003

perror_plus("asprintf");

1209

2004

continue;

1210

2005

}

1211

2006

ret = remove(fullname);

1215

2010

}

1216

2011

free(fullname);

1217

2012

}

1218

closedir(d);

2013

}

2014

2015

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

2016

specify */

2017

free(direntries);

2018

if (ret == -1){

2019

perror_plus("scandir");

1219

2020

}

1220

2021

ret = rmdir(tempdir);

1221

2022

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

1222

perror("rmdir");

1223

}

2023

perror_plus("rmdir");

2024

}

2025

}

2026

2027

if(quit_now){

2028

sigemptyset(&old_sigterm_action.sa_mask);

2029

old_sigterm_action.sa_handler = SIG_DFL;

2030

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

2031

&old_sigterm_action,

2032

NULL));

2033

if(ret == -1){

2034

perror_plus("sigaction");

2035

}

2036

do {

2037

ret = raise(signal_received);

2038

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

2039

if(ret != 0){

2040

perror_plus("raise");

2041

abort();

2042

}

2043

TEMP_FAILURE_RETRY(pause());

1224

2044

}

1225

2045

1226

2046

return exitcode;