/mandos/release : revision 115

32

#define _LARGEFILE_SOURCE

33

#define _FILE_OFFSET_BITS 64

34

35

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */

35

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

36

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 */

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() */

44

58

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

45

SIOCSIFFLAGS */

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 */

46

71

72

/* Avahi */

73

/* All Avahi types, constants and functions

74

Avahi*, avahi_*,

75

AVAHI_* */

47

76

#include <avahi-core/core.h>

48

77

#include <avahi-core/lookup.h>

49

78

#include <avahi-core/log.h>

51

80

#include <avahi-common/malloc.h>

52

81

#include <avahi-common/error.h>

53

82

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 */

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 */

60

91

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() */

71

92

/* GPGME */

72

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

73

#include <gpgme.h>

93

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

94

functions:

95

gpgme_*

96

GPGME_PROTOCOL_OpenPGP,

97

GPG_ERR_NO_* */

74

98

75

99

#define BUFFER_SIZE 256

76

100

77

101

bool debug = false;

78

102

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

79

const char *argp_program_version = "mandosclient 0.9";

103

static const char mandos_protocol_version[] = "1";

104

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

80

105

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

81

static const char mandos_protocol_version[] = "1";

82

106

83

107

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

84

108

typedef struct {

90

114

const char *priority;

91

115

} mandos_context;

92

116

93

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

117

/*

118

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

94

119

* "buffer_capacity" is how much is currently allocated,

95

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

120

* "buffer_length" is how much is already used.

121

*/

96

122

size_t adjustbuffer(char **buffer, size_t buffer_length,

97

123

size_t buffer_capacity){

98

124

if (buffer_length + BUFFER_SIZE > buffer_capacity){

188

214

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

189

215

gpgme_strsource(rc), gpgme_strerror(rc));

190

216

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

}

191

245

goto decrypt_end;

192

246

}

193

247

195

249

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

196

250

}

197

251

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

227

252

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

228

253

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

229

254

perror("pgpme_data_seek");

276

301

}

277

302

278

303

static const char * safer_gnutls_strerror (int value) {

279

const char *ret = gnutls_strerror (value);

304

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

280

305

if (ret == NULL)

281

306

ret = "(unknown)";

282

307

return ret;

289

314

}

290

315

291

316

static int init_gnutls_global(mandos_context *mc,

292

const char *pubkeyfile,

293

const char *seckeyfile){

317

const char *pubkeyfilename,

318

const char *seckeyfilename){

294

319

int ret;

295

320

296

321

if(debug){

297

322

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

298

323

}

299

300

if ((ret = gnutls_global_init ())

301

!= GNUTLS_E_SUCCESS) {

324

325

ret = gnutls_global_init();

326

if (ret != GNUTLS_E_SUCCESS) {

302

327

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

303

328

safer_gnutls_strerror(ret));

304

329

return -1;

313

338

}

314

339

315

340

/* OpenPGP credentials */

316

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

317

!= GNUTLS_E_SUCCESS) {

318

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

341

gnutls_certificate_allocate_credentials(&mc->cred);

342

if (ret != GNUTLS_E_SUCCESS){

343

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

344

warning */

319

345

safer_gnutls_strerror(ret));

346

gnutls_global_deinit ();

320

347

return -1;

321

348

}

322

349

323

350

if(debug){

324

351

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

325

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

326

seckeyfile);

352

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

353

seckeyfilename);

327

354

}

328

355

329

356

ret = gnutls_certificate_set_openpgp_key_file

330

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

357

(mc->cred, pubkeyfilename, seckeyfilename,

358

GNUTLS_OPENPGP_FMT_BASE64);

331

359

if (ret != GNUTLS_E_SUCCESS) {

332

360

fprintf(stderr,

333

361

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

334

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

362

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

335

363

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

336

364

safer_gnutls_strerror(ret));

337

return -1;

365

goto globalfail;

338

366

}

339

367

340

368

/* GnuTLS server initialization */

342

370

if (ret != GNUTLS_E_SUCCESS) {

343

371

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

344

372

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

345

return -1;

373

goto globalfail;

346

374

}

347

375

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

348

376

if (ret != GNUTLS_E_SUCCESS) {

349

377

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

350

378

safer_gnutls_strerror(ret));

351

return -1;

379

goto globalfail;

352

380

}

353

381

354

382

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

355

383

356

384

return 0;

385

386

globalfail:

387

388

gnutls_certificate_free_credentials(mc->cred);

389

gnutls_global_deinit();

390

return -1;

391

357

392

}

358

393

359

394

static int init_gnutls_session(mandos_context *mc,

373

408

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

374

409

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

375

410

safer_gnutls_strerror(ret));

411

gnutls_deinit (*session);

376

412

return -1;

377

413

}

378

414

}

382

418

if (ret != GNUTLS_E_SUCCESS) {

383

419

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

384

420

safer_gnutls_strerror(ret));

421

gnutls_deinit (*session);

385

422

return -1;

386

423

}

387

424

420

457

}

421

458

422

459

if(debug){

423

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

424

ip, port);

460

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

461

"\n", ip, port);

425

462

}

426

463

427

464

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

438

475

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

439

476

}

440

477

441

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

478

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

442

479

to.in6.sin6_family = AF_INET6;

443

480

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

444

481

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

451

488

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

452

489

return -1;

453

490

}

454

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

491

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

455

492

456

493

to.in6.sin6_scope_id = (uint32_t)if_index;

457

494

458

495

if(debug){

459

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

496

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

497

port);

460

498

char addrstr[INET6_ADDRSTRLEN] = "";

461

499

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

462

500

sizeof(addrstr)) == NULL){

503

541

}

504

542

505

543

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

506

507

ret = gnutls_handshake (session);

544

545

do{

546

ret = gnutls_handshake (session);

547

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

508

548

509

549

if (ret != GNUTLS_E_SUCCESS){

510

550

if(debug){

542

582

case GNUTLS_E_AGAIN:

543

583

break;

544

584

case GNUTLS_E_REHANDSHAKE:

545

ret = gnutls_handshake (session);

585

do{

586

ret = gnutls_handshake (session);

587

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

546

588

if (ret < 0){

547

589

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

548

590

gnutls_perror (ret);

593

635

} else {

594

636

retval = -1;

595

637

}

638

} else {

639

retval = -1;

596

640

}

597

641

598

642

/* Shutdown procedure */

601

645

free(buffer);

602

646

close(tcp_sd);

603

647

gnutls_deinit (session);

604

gnutls_certificate_free_credentials (mc->cred);

605

gnutls_global_deinit ();

606

648

return retval;

607

649

}

608

650

621

663

flags,

622

664

void* userdata) {

623

665

mandos_context *mc = userdata;

624

assert(r); /* Spurious warning */

666

assert(r);

625

667

626

668

/* Called whenever a service has been resolved successfully or

627

669

timed out */

639

681

char ip[AVAHI_ADDRESS_STR_MAX];

640

682

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

641

683

if(debug){

642

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

643

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

684

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

685

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

686

interface, port);

644

687

}

645

688

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

646

689

if (ret == 0){

647

exit(EXIT_SUCCESS);

690

avahi_simple_poll_quit(mc->simple_poll);

648

691

}

649

692

}

650

693

}

662

705

flags,

663

706

void* userdata) {

664

707

mandos_context *mc = userdata;

665

assert(b); /* Spurious warning */

708

assert(b);

666

709

667

710

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

668

711

is removed from the LAN */

704

747

705

748

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

706

749

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

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){

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){

712

754

return NULL;

713

755

}

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';

722

756

return tmp;

723

757

}

724

758

735

769

gid_t gid;

736

770

char *connect_to = NULL;

737

771

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

738

const char *pubkeyfile = "pubkey.txt";

739

const char *seckeyfile = "seckey.txt";

772

char *pubkeyfilename = NULL;

773

char *seckeyfilename = NULL;

774

const char *pubkeyname = "pubkey.txt";

775

const char *seckeyname = "seckey.txt";

740

776

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

741

777

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

778

bool gnutls_initalized = false;

742

779

743

780

{

744

781

struct argp_option options[] = {

793

830

keydir = arg;

794

831

break;

795

832

case 's':

796

seckeyfile = arg;

833

seckeyname = arg;

797

834

break;

798

835

case 'p':

799

pubkeyfile = arg;

836

pubkeyname = arg;

800

837

break;

801

838

case 129:

802

839

errno = 0;

811

848

break;

812

849

case ARGP_KEY_ARG:

813

850

argp_usage (state);

851

case ARGP_KEY_END:

814

852

break;

815

case ARGP_KEY_END:

816

break;

817

853

default:

818

854

return ARGP_ERR_UNKNOWN;

819

855

}

824

860

.args_doc = "",

825

861

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

826

862

" passwords from mandos server" };

827

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

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

}

828

869

}

829

870

830

pubkeyfile = combinepath(keydir, pubkeyfile);

831

if (pubkeyfile == NULL){

871

pubkeyfilename = combinepath(keydir, pubkeyname);

872

if (pubkeyfilename == NULL){

832

873

perror("combinepath");

833

874

exitcode = EXIT_FAILURE;

834

875

goto end;

835

876

}

836

877

837

seckeyfile = combinepath(keydir, seckeyfile);

838

if (seckeyfile == NULL){

878

seckeyfilename = combinepath(keydir, seckeyname);

879

if (seckeyfilename == NULL){

839

880

perror("combinepath");

881

exitcode = EXIT_FAILURE;

840

882

goto end;

841

883

}

842

884

843

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

885

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

844

886

if (ret == -1){

845

fprintf(stderr, "init_gnutls_global\n");

887

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

888

exitcode = EXIT_FAILURE;

846

889

goto end;

847

}

848

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

849

921

uid = getuid();

850

922

gid = getgid();

851

923

852

924

ret = setuid(uid);

853

925

if (ret == -1){

854

926

perror("setuid");

892

964

goto end;

893

965

}

894

966

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

922

967

if (not debug){

923

968

avahi_set_log_function(empty_log);

924

969

}

996

1041

997

1042

if (mc.simple_poll != NULL)

998

1043

avahi_simple_poll_free(mc.simple_poll);

999

free(pubkeyfile);

1000

free(seckeyfile);

1044

free(pubkeyfilename);

1045

free(seckeyfilename);

1046

1047

if (gnutls_initalized){

1048

gnutls_certificate_free_credentials(mc.cred);

1049

gnutls_global_deinit ();

1050

}

1001

1051

1002

1052

return exitcode;

1003

1053

}