/mandos/trunk : revision 24.1.16

32

#define _LARGEFILE_SOURCE

33

#define _FILE_OFFSET_BITS 64

34

35

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

35

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */

36

37

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

38

stdout, ferror() */

39

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

40

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

41

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

42

srand() */

43

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

44

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

45

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

46

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

47

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

48

sockaddr_in6, PF_INET6,

49

SOCK_STREAM, INET6_ADDRSTRLEN,

50

uid_t, gid_t */

51

#include <inttypes.h> /* PRIu16 */

52

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

53

struct in6_addr, inet_pton(),

54

connect() */

55

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

56

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

57

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

37

#include <stdio.h>

38

#include <assert.h>

39

#include <stdlib.h>

40

#include <time.h>

41

#include <net/if.h> /* if_nametoindex */

42

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

43

SIOCSIFFLAGS */

58

44

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

59

SIOCSIFFLAGS, if_indextoname(),

60

if_nametoindex(), IF_NAMESIZE */

61

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

62

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

63

setgid() */

64

#include <netinet/in.h>

65

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

66

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

67

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

68

argp_state, struct argp,

69

argp_parse(), ARGP_KEY_ARG,

70

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

45

SIOCSIFFLAGS */

71

46

72

/* Avahi */

73

/* All Avahi types, constants and functions

74

Avahi*, avahi_*,

75

AVAHI_* */

76

47

#include <avahi-core/core.h>

77

48

#include <avahi-core/lookup.h>

78

49

#include <avahi-core/log.h>

80

51

#include <avahi-common/malloc.h>

81

52

#include <avahi-common/error.h>

82

53

83

/* GnuTLS */

84

#include <gnutls/gnutls.h> /* All GnuTLS types, constants and

85

functions:

86

gnutls_*

87

init_gnutls_session(),

88

GNUTLS_* */

89

#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),

90

GNUTLS_OPENPGP_FMT_BASE64 */

54

/* Mandos client part */

55

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

56

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

57

struct in6_addr, inet_pton() */

58

#include <gnutls/gnutls.h> /* All GnuTLS stuff */

59

#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */

91

60

61

#include <unistd.h> /* close() */

62

#include <netinet/in.h>

63

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

64

#include <string.h> /* memset */

65

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

66

#include <iso646.h> /* not */

67

#include <net/if.h> /* IF_NAMESIZE */

68

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

69

struct argp_state, struct argp,

70

argp_parse() */

92

71

/* GPGME */

93

#include <gpgme.h> /* All GPGME types, constants and

94

functions:

95

gpgme_*

96

GPGME_PROTOCOL_OpenPGP,

97

GPG_ERR_NO_* */

72

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

73

#include <gpgme.h>

98

74

99

75

#define BUFFER_SIZE 256

100

76

101

77

bool debug = false;

102

78

static const char *keydir = "/conf/conf.d/mandos";

79

const char *argp_program_version = "mandosclient 0.9";

80

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

103

81

static const char mandos_protocol_version[] = "1";

104

const char *argp_program_version = "password-request 1.0";

105

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

106

82

107

83

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

108

84

typedef struct {

114

90

const char *priority;

115

91

} mandos_context;

116

92

117

/*

118

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

93

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

119

94

* "buffer_capacity" is how much is currently allocated,

120

* "buffer_length" is how much is already used.

121

*/

95

* "buffer_length" is how much is already used. */

122

96

size_t adjustbuffer(char **buffer, size_t buffer_length,

123

97

size_t buffer_capacity){

124

98

if (buffer_length + BUFFER_SIZE > buffer_capacity){

214

188

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

215

189

gpgme_strsource(rc), gpgme_strerror(rc));

216

190

plaintext_length = -1;

217

if (debug){

218

gpgme_decrypt_result_t result;

219

result = gpgme_op_decrypt_result(ctx);

220

if (result == NULL){

221

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

222

} else {

223

fprintf(stderr, "Unsupported algorithm: %s\n",

224

result->unsupported_algorithm);

225

fprintf(stderr, "Wrong key usage: %u\n",

226

result->wrong_key_usage);

227

if(result->file_name != NULL){

228

fprintf(stderr, "File name: %s\n", result->file_name);

229

}

230

gpgme_recipient_t recipient;

231

recipient = result->recipients;

232

if(recipient){

233

while(recipient != NULL){

234

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

235

gpgme_pubkey_algo_name(recipient->pubkey_algo));

236

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

237

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

238

recipient->status == GPG_ERR_NO_SECKEY

239

? "No" : "Yes");

240

recipient = recipient->next;

241

}

242

}

243

}

244

}

245

191

goto decrypt_end;

246

192

}

247

193

249

195

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

250

196

}

251

197

198

if (debug){

199

gpgme_decrypt_result_t result;

200

result = gpgme_op_decrypt_result(ctx);

201

if (result == NULL){

202

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

203

} else {

204

fprintf(stderr, "Unsupported algorithm: %s\n",

205

result->unsupported_algorithm);

206

fprintf(stderr, "Wrong key usage: %d\n",

207

result->wrong_key_usage);

208

if(result->file_name != NULL){

209

fprintf(stderr, "File name: %s\n", result->file_name);

210

}

211

gpgme_recipient_t recipient;

212

recipient = result->recipients;

213

if(recipient){

214

while(recipient != NULL){

215

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

216

gpgme_pubkey_algo_name(recipient->pubkey_algo));

217

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

218

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

219

recipient->status == GPG_ERR_NO_SECKEY

220

? "No" : "Yes");

221

recipient = recipient->next;

222

}

223

}

224

}

225

}

226

252

227

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

253

228

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

254

229

perror("pgpme_data_seek");

301

276

}

302

277

303

278

static const char * safer_gnutls_strerror (int value) {

304

const char *ret = gnutls_strerror (value); /* Spurious warning */

279

const char *ret = gnutls_strerror (value);

305

280

if (ret == NULL)

306

281

ret = "(unknown)";

307

282

return ret;

314

289

}

315

290

316

291

static int init_gnutls_global(mandos_context *mc,

317

const char *pubkeyfilename,

318

const char *seckeyfilename){

292

const char *pubkeyfile,

293

const char *seckeyfile){

319

294

int ret;

320

295

321

296

if(debug){

322

297

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

323

298

}

324

325

ret = gnutls_global_init();

326

if (ret != GNUTLS_E_SUCCESS) {

299

300

if ((ret = gnutls_global_init ())

301

!= GNUTLS_E_SUCCESS) {

327

302

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

328

303

safer_gnutls_strerror(ret));

329

304

return -1;

338

313

}

339

314

340

315

/* OpenPGP credentials */

341

gnutls_certificate_allocate_credentials(&mc->cred);

342

if (ret != GNUTLS_E_SUCCESS){

343

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

344

warning */

316

if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))

317

!= GNUTLS_E_SUCCESS) {

318

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

345

319

safer_gnutls_strerror(ret));

346

gnutls_global_deinit ();

347

320

return -1;

348

321

}

349

322

350

323

if(debug){

351

324

fprintf(stderr, "Attempting to use OpenPGP certificate %s"

352

" and keyfile %s as GnuTLS credentials\n", pubkeyfilename,

353

seckeyfilename);

325

" and keyfile %s as GnuTLS credentials\n", pubkeyfile,

326

seckeyfile);

354

327

}

355

328

356

329

ret = gnutls_certificate_set_openpgp_key_file

357

(mc->cred, pubkeyfilename, seckeyfilename,

358

GNUTLS_OPENPGP_FMT_BASE64);

330

(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);

359

331

if (ret != GNUTLS_E_SUCCESS) {

360

332

fprintf(stderr,

361

333

"Error[%d] while reading the OpenPGP key pair ('%s',"

362

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

334

" '%s')\n", ret, pubkeyfile, seckeyfile);

363

335

fprintf(stdout, "The GnuTLS error is: %s\n",

364

336

safer_gnutls_strerror(ret));

365

goto globalfail;

337

return -1;

366

338

}

367

339

368

340

/* GnuTLS server initialization */

370

342

if (ret != GNUTLS_E_SUCCESS) {

371

343

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

372

344

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

373

goto globalfail;

345

return -1;

374

346

}

375

347

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

376

348

if (ret != GNUTLS_E_SUCCESS) {

377

349

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

378

350

safer_gnutls_strerror(ret));

379

goto globalfail;

351

return -1;

380

352

}

381

353

382

354

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

383

355

384

356

return 0;

385

386

globalfail:

387

388

gnutls_certificate_free_credentials(mc->cred);

389

gnutls_global_deinit();

390

return -1;

391

392

357

}

393

358

394

359

static int init_gnutls_session(mandos_context *mc,

408

373

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

409

374

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

410

375

safer_gnutls_strerror(ret));

411

gnutls_deinit (*session);

412

376

return -1;

413

377

}

414

378

}

418

382

if (ret != GNUTLS_E_SUCCESS) {

419

383

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

420

384

safer_gnutls_strerror(ret));

421

gnutls_deinit (*session);

422

385

return -1;

423

386

}

424

387

457

420

}

458

421

459

422

if(debug){

460

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

461

"\n", ip, port);

423

fprintf(stderr, "Setting up a tcp connection to %s, port %d\n",

424

ip, port);

462

425

}

463

426

464

427

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

475

438

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

476

439

}

477

440

478

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

441

memset(&to,0,sizeof(to)); /* Spurious warning */

479

442

to.in6.sin6_family = AF_INET6;

480

443

/* It would be nice to have a way to detect if we were passed an

481

444

IPv4 address here. Now we assume an IPv6 address. */

488

451

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

489

452

return -1;

490

453

}

491

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

454

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

492

455

493

456

to.in6.sin6_scope_id = (uint32_t)if_index;

494

457

495

458

if(debug){

496

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

497

port);

459

fprintf(stderr, "Connection to: %s, port %d\n", ip, port);

498

460

char addrstr[INET6_ADDRSTRLEN] = "";

499

461

if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,

500

462

sizeof(addrstr)) == NULL){

541

503

}

542

504

543

505

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

544

545

do{

546

ret = gnutls_handshake (session);

547

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

506

507

ret = gnutls_handshake (session);

548

508

549

509

if (ret != GNUTLS_E_SUCCESS){

550

510

if(debug){

582

542

case GNUTLS_E_AGAIN:

583

543

break;

584

544

case GNUTLS_E_REHANDSHAKE:

585

do{

586

ret = gnutls_handshake (session);

587

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

545

ret = gnutls_handshake (session);

588

546

if (ret < 0){

589

547

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

590

548

gnutls_perror (ret);

635

593

} else {

636

594

retval = -1;

637

595

}

638

} else {

639

retval = -1;

640

596

}

641

597

642

598

/* Shutdown procedure */

645

601

free(buffer);

646

602

close(tcp_sd);

647

603

gnutls_deinit (session);

604

gnutls_certificate_free_credentials (mc->cred);

605

gnutls_global_deinit ();

648

606

return retval;

649

607

}

650

608

663

621

flags,

664

622

void* userdata) {

665

623

mandos_context *mc = userdata;

666

assert(r);

624

assert(r); /* Spurious warning */

667

625

668

626

/* Called whenever a service has been resolved successfully or

669

627

timed out */

681

639

char ip[AVAHI_ADDRESS_STR_MAX];

682

640

avahi_address_snprint(ip, sizeof(ip), address);

683

641

if(debug){

684

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"

685

PRIu16 ") on port %d\n", name, host_name, ip,

686

interface, port);

642

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %d) on"

643

" port %d\n", name, host_name, ip, interface, port);

687

644

}

688

645

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

689

646

if (ret == 0){

690

avahi_simple_poll_quit(mc->simple_poll);

647

exit(EXIT_SUCCESS);

691

648

}

692

649

}

693

650

}

705

662

flags,

706

663

void* userdata) {

707

664

mandos_context *mc = userdata;

708

assert(b);

665

assert(b); /* Spurious warning */

709

666

710

667

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

711

668

is removed from the LAN */

747

704

748

705

/* Combines file name and path and returns the malloced new

749

706

string. some sane checks could/should be added */

750

static char *combinepath(const char *first, const char *second){

751

char *tmp;

752

int ret = asprintf(&tmp, "%s/%s", first, second);

753

if(ret < 0){

707

static const char *combinepath(const char *first, const char *second){

708

size_t f_len = strlen(first);

709

size_t s_len = strlen(second);

710

char *tmp = malloc(f_len + s_len + 2);

711

if (tmp == NULL){

754

712

return NULL;

755

713

}

714

if(f_len > 0){

715

memcpy(tmp, first, f_len); /* Spurious warning */

716

}

717

tmp[f_len] = '/';

718

if(s_len > 0){

719

memcpy(tmp + f_len + 1, second, s_len); /* Spurious warning */

720

}

721

tmp[f_len + 1 + s_len] = '\0';

756

722

return tmp;

757

723

}

758

724

769

735

gid_t gid;

770

736

char *connect_to = NULL;

771

737

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

772

char *pubkeyfilename = NULL;

773

char *seckeyfilename = NULL;

774

const char *pubkeyname = "pubkey.txt";

775

const char *seckeyname = "seckey.txt";

738

const char *pubkeyfile = "pubkey.txt";

739

const char *seckeyfile = "seckey.txt";

776

740

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

777

741

.dh_bits = 1024, .priority = "SECURE256"};

778

bool gnutls_initalized = false;

779

742

780

743

{

781

744

struct argp_option options[] = {

830

793

keydir = arg;

831

794

break;

832

795

case 's':

833

seckeyname = arg;

796

seckeyfile = arg;

834

797

break;

835

798

case 'p':

836

pubkeyname = arg;

799

pubkeyfile = arg;

837

800

break;

838

801

case 129:

839

802

errno = 0;

848

811

break;

849

812

case ARGP_KEY_ARG:

850

813

argp_usage (state);

851

case ARGP_KEY_END:

852

814

break;

815

case ARGP_KEY_END:

816

break;

853

817

default:

854

818

return ARGP_ERR_UNKNOWN;

855

819

}

860

824

.args_doc = "",

861

825

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

862

826

" passwords from mandos server" };

863

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

864

if (ret == ARGP_ERR_UNKNOWN){

865

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

866

exitcode = EXIT_FAILURE;

867

goto end;

868

}

827

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

869

828

}

870

829

871

pubkeyfilename = combinepath(keydir, pubkeyname);

872

if (pubkeyfilename == NULL){

830

pubkeyfile = combinepath(keydir, pubkeyfile);

831

if (pubkeyfile == NULL){

873

832

perror("combinepath");

874

833

exitcode = EXIT_FAILURE;

875

834

goto end;

876

835

}

877

836

878

seckeyfilename = combinepath(keydir, seckeyname);

879

if (seckeyfilename == NULL){

837

seckeyfile = combinepath(keydir, seckeyfile);

838

if (seckeyfile == NULL){

880

839

perror("combinepath");

881

exitcode = EXIT_FAILURE;

882

840

goto end;

883

841

}

884

842

885

ret = init_gnutls_global(&mc, pubkeyfilename, seckeyfilename);

843

ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);

886

844

if (ret == -1){

887

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

888

exitcode = EXIT_FAILURE;

845

fprintf(stderr, "init_gnutls_global\n");

889

846

goto end;

890

} else {

891

gnutls_initalized = true;

892

}

893

894

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

895

{

896

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

897

if(sd < 0) {

898

perror("socket");

899

exitcode = EXIT_FAILURE;

900

goto end;

901

}

902

strcpy(network.ifr_name, interface);

903

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

904

if(ret == -1){

905

perror("ioctl SIOCGIFFLAGS");

906

exitcode = EXIT_FAILURE;

907

goto end;

908

}

909

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

910

network.ifr_flags |= IFF_UP;

911

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

912

if(ret == -1){

913

perror("ioctl SIOCSIFFLAGS");

914

exitcode = EXIT_FAILURE;

915

goto end;

916

}

917

}

918

close(sd);

919

}

920

847

}

848

921

849

uid = getuid();

922

850

gid = getgid();

923

851

924

852

ret = setuid(uid);

925

853

if (ret == -1){

926

854

perror("setuid");

964

892

goto end;

965

893

}

966

894

895

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

896

{

897

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

898

if(sd < 0) {

899

perror("socket");

900

exitcode = EXIT_FAILURE;

901

goto end;

902

}

903

strcpy(network.ifr_name, interface); /* Spurious warning */

904

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

905

if(ret == -1){

906

perror("ioctl SIOCGIFFLAGS");

907

exitcode = EXIT_FAILURE;

908

goto end;

909

}

910

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

911

network.ifr_flags |= IFF_UP;

912

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

913

if(ret == -1){

914

perror("ioctl SIOCSIFFLAGS");

915

exitcode = EXIT_FAILURE;

916

goto end;

917

}

918

}

919

close(sd);

920

}

921

967

922

if (not debug){

968

923

avahi_set_log_function(empty_log);

969

924

}

1041

996

1042

997

if (mc.simple_poll != NULL)

1043

998

avahi_simple_poll_free(mc.simple_poll);

1044

free(pubkeyfilename);

1045

free(seckeyfilename);

1046

1047

if (gnutls_initalized){

1048

gnutls_certificate_free_credentials(mc.cred);

1049

gnutls_global_deinit ();

1050

}

999

free(pubkeyfile);

1000

free(seckeyfile);

1051

1001

1052

1002

return exitcode;

1053

1003

}