/mandos/trunk : revision 68

34

35

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */

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(), stdout,

38

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(), memcpy(), 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 */

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 */

83

/* GnuTLS */

84

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

85

gnutls_*

86

init_gnutls_session(),

87

GNUTLS_* */

88

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

89

GNUTLS_OPENPGP_FMT_BASE64 */

68

90

69

91

/* GPGME */

70

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

71

#include <gpgme.h>

72

73

/* getopt_long */

74

#include <getopt.h>

92

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

93

gpgme_*

94

GPGME_PROTOCOL_OpenPGP,

95

GPG_ERR_NO_* */

75

96

76

97

#define BUFFER_SIZE 256

77

98

99

bool debug = false;

78

100

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

79

static const char *pubkeyfile = "pubkey.txt";

80

static const char *seckeyfile = "seckey.txt";

81

82

bool debug = false;

83

84

const char mandos_protocol_version[] = "1";

85

86

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

101

static const char mandos_protocol_version[] = "1";

102

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

103

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

104

105

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

87

106

typedef struct {

88

107

AvahiSimplePoll *simple_poll;

89

108

AvahiServer *server;

90

109

gnutls_certificate_credentials_t cred;

91

110

unsigned int dh_bits;

111

gnutls_dh_params_t dh_params;

92

112

const char *priority;

93

113

} mandos_context;

94

114

115

/*

116

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

117

* "buffer_capacity" is how much is currently allocated,

118

* "buffer_length" is how much is already used.

119

*/

95

120

size_t adjustbuffer(char **buffer, size_t buffer_length,

96

121

size_t buffer_capacity){

97

122

if (buffer_length + BUFFER_SIZE > buffer_capacity){

202

227

} else {

203

228

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

204

229

result->unsupported_algorithm);

205

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

230

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

206

231

result->wrong_key_usage);

207

232

if(result->file_name != NULL){

208

233

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

232

257

233

258

*plaintext = NULL;

234

259

while(true){

235

plaintext_capacity = adjustbuffer(plaintext, (size_t)plaintext_length,

260

plaintext_capacity = adjustbuffer(plaintext,

261

(size_t)plaintext_length,

236

262

plaintext_capacity);

237

263

if (plaintext_capacity == 0){

238

264

perror("adjustbuffer");

286

312

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

287

313

}

288

314

289

static int initgnutls(mandos_context *mc, gnutls_session_t *session,

290

gnutls_dh_params_t *dh_params){

315

static int init_gnutls_global(mandos_context *mc,

316

const char *pubkeyfile,

317

const char *seckeyfile){

291

318

int ret;

292

319

293

320

if(debug){

294

321

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

295

322

}

296

297

if ((ret = gnutls_global_init ())

298

!= GNUTLS_E_SUCCESS) {

323

324

ret = gnutls_global_init();

325

if (ret != GNUTLS_E_SUCCESS) {

299

326

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

300

327

safer_gnutls_strerror(ret));

301

328

return -1;

310

337

}

311

338

312

339

/* OpenPGP credentials */

313

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

314

!= GNUTLS_E_SUCCESS) {

340

gnutls_certificate_allocate_credentials(&mc->cred);

341

if (ret != GNUTLS_E_SUCCESS){

315

342

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

316

343

safer_gnutls_strerror(ret));

344

gnutls_global_deinit ();

317

345

return -1;

318

346

}

319

347

331

359

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

332

360

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

333

361

safer_gnutls_strerror(ret));

334

return -1;

362

goto globalfail;

335

363

}

336

364

337

365

/* GnuTLS server initialization */

338

ret = gnutls_dh_params_init(dh_params);

366

ret = gnutls_dh_params_init(&mc->dh_params);

339

367

if (ret != GNUTLS_E_SUCCESS) {

340

368

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

341

369

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

342

return -1;

370

goto globalfail;

343

371

}

344

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

372

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

345

373

if (ret != GNUTLS_E_SUCCESS) {

346

374

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

347

375

safer_gnutls_strerror(ret));

348

return -1;

376

goto globalfail;

349

377

}

350

378

351

gnutls_certificate_set_dh_params(mc->cred, *dh_params);

352

379

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

380

381

return 0;

382

383

globalfail:

384

385

gnutls_certificate_free_credentials(mc->cred);

386

gnutls_global_deinit();

387

return -1;

388

389

}

390

391

static int init_gnutls_session(mandos_context *mc,

392

gnutls_session_t *session){

393

int ret;

353

394

/* GnuTLS session creation */

354

395

ret = gnutls_init(session, GNUTLS_SERVER);

355

396

if (ret != GNUTLS_E_SUCCESS){

364

405

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

365

406

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

366

407

safer_gnutls_strerror(ret));

408

gnutls_deinit (*session);

367

409

return -1;

368

410

}

369

411

}

373

415

if (ret != GNUTLS_E_SUCCESS) {

374

416

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

375

417

safer_gnutls_strerror(ret));

418

gnutls_deinit (*session);

376

419

return -1;

377

420

}

378

421

394

437

AvahiIfIndex if_index,

395

438

mandos_context *mc){

396

439

int ret, tcp_sd;

397

struct sockaddr_in6 to;

440

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

398

441

char *buffer = NULL;

399

442

char *decrypted_buffer;

400

443

size_t buffer_length = 0;

404

447

int retval = 0;

405

448

char interface[IF_NAMESIZE];

406

449

gnutls_session_t session;

407

gnutls_dh_params_t dh_params;

408

450

409

ret = initgnutls (mc, &session, &dh_params);

451

ret = init_gnutls_session (mc, &session);

410

452

if (ret != 0){

411

453

return -1;

412

454

}

413

455

414

456

if(debug){

415

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

416

ip, port);

457

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

458

"\n", ip, port);

417

459

}

418

460

419

461

tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);

431

473

}

432

474

433

475

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

434

to.sin6_family = AF_INET6;

476

to.in6.sin6_family = AF_INET6;

435

477

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

436

478

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

437

ret = inet_pton(AF_INET6, ip, &to.sin6_addr);

479

ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);

438

480

if (ret < 0 ){

439

481

perror("inet_pton");

440

482

return -1;

443

485

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

444

486

return -1;

445

487

}

446

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

488

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

447

489

448

to.sin6_scope_id = (uint32_t)if_index;

490

to.in6.sin6_scope_id = (uint32_t)if_index;

449

491

450

492

if(debug){

451

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

493

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

494

port);

452

495

char addrstr[INET6_ADDRSTRLEN] = "";

453

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

496

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

454

497

sizeof(addrstr)) == NULL){

455

498

perror("inet_ntop");

456

499

} else {

460

503

}

461

504

}

462

505

463

ret = connect(tcp_sd, (struct sockaddr *) &to, sizeof(to));

506

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

464

507

if (ret < 0){

465

508

perror("connect");

466

509

return -1;

495

538

}

496

539

497

540

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

498

499

ret = gnutls_handshake (session);

541

542

do{

543

ret = gnutls_handshake (session);

544

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

500

545

501

546

if (ret != GNUTLS_E_SUCCESS){

502

547

if(debug){

515

560

}

516

561

517

562

while(true){

518

buffer_capacity = adjustbuffer(&buffer, buffer_length, buffer_capacity);

563

buffer_capacity = adjustbuffer(&buffer, buffer_length,

564

buffer_capacity);

519

565

if (buffer_capacity == 0){

520

566

perror("adjustbuffer");

521

567

retval = -1;

533

579

case GNUTLS_E_AGAIN:

534

580

break;

535

581

case GNUTLS_E_REHANDSHAKE:

536

ret = gnutls_handshake (session);

582

do{

583

ret = gnutls_handshake (session);

584

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

537

585

if (ret < 0){

538

586

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

539

587

gnutls_perror (ret);

592

640

free(buffer);

593

641

close(tcp_sd);

594

642

gnutls_deinit (session);

595

gnutls_certificate_free_credentials (mc->cred);

596

gnutls_global_deinit ();

597

643

return retval;

598

644

}

599

645

630

676

char ip[AVAHI_ADDRESS_STR_MAX];

631

677

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

632

678

if(debug){

633

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

634

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

679

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

680

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

681

interface, port);

635

682

}

636

683

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

637

684

if (ret == 0){

722

769

const char *interface = "eth0";

723

770

struct ifreq network;

724

771

int sd;

772

uid_t uid;

773

gid_t gid;

725

774

char *connect_to = NULL;

726

775

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

776

const char *pubkeyfile = "pubkey.txt";

777

const char *seckeyfile = "seckey.txt";

727

778

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

728

779

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

780

bool gnutls_initalized = false;

729

781

730

782

{

731

/* Temporary int to get the address of for getopt_long */

732

int debug_int = debug ? 1 : 0;

733

while (true){

734

struct option long_options[] = {

735

{"debug", no_argument, &debug_int, 1},

736

{"connect", required_argument, NULL, 'c'},

737

{"interface", required_argument, NULL, 'i'},

738

{"keydir", required_argument, NULL, 'd'},

739

{"seckey", required_argument, NULL, 's'},

740

{"pubkey", required_argument, NULL, 'p'},

741

{"dh-bits", required_argument, NULL, 'D'},

742

{"priority", required_argument, NULL, 'P'},

743

{0, 0, 0, 0} };

744

745

int option_index = 0;

746

ret = getopt_long (argc, argv, "i:", long_options,

747

&option_index);

748

749

if (ret == -1){

783

struct argp_option options[] = {

784

{ .name = "debug", .key = 128,

785

.doc = "Debug mode", .group = 3 },

786

{ .name = "connect", .key = 'c',

787

.arg = "IP",

788

.doc = "Connect directly to a sepcified mandos server",

789

.group = 1 },

790

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

791

.arg = "INTERFACE",

792

.doc = "Interface that Avahi will conntect through",

793

.group = 1 },

794

{ .name = "keydir", .key = 'd',

795

.arg = "KEYDIR",

796

.doc = "Directory where the openpgp keyring is",

797

.group = 1 },

798

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

799

.arg = "SECKEY",

800

.doc = "Secret openpgp key for gnutls authentication",

801

.group = 1 },

802

{ .name = "pubkey", .key = 'p',

803

.arg = "PUBKEY",

804

.doc = "Public openpgp key for gnutls authentication",

805

.group = 2 },

806

{ .name = "dh-bits", .key = 129,

807

.arg = "BITS",

808

.doc = "dh-bits to use in gnutls communication",

809

.group = 2 },

810

{ .name = "priority", .key = 130,

811

.arg = "PRIORITY",

812

.doc = "GNUTLS priority", .group = 1 },

813

{ .name = NULL }

814

};

815

816

817

error_t parse_opt (int key, char *arg,

818

struct argp_state *state) {

819

/* Get the INPUT argument from `argp_parse', which we know is

820

a pointer to our plugin list pointer. */

821

switch (key) {

822

case 128:

823

debug = true;

750

824

break;

751

}

752

753

switch(ret){

754

case 0:

825

case 'c':

826

connect_to = arg;

755

827

break;

756

828

case 'i':

757

interface = optarg;

758

break;

759

case 'c':

760

connect_to = optarg;

829

interface = arg;

761

830

break;

762

831

case 'd':

763

keydir = optarg;

832

keydir = arg;

833

break;

834

case 's':

835

seckeyfile = arg;

764

836

break;

765

837

case 'p':

766

pubkeyfile = optarg;

767

break;

768

case 's':

769

seckeyfile = optarg;

770

break;

771

case 'D':

838

pubkeyfile = arg;

839

break;

840

case 129:

772

841

errno = 0;

773

mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);

842

mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);

774

843

if (errno){

775

844

perror("strtol");

776

845

exit(EXIT_FAILURE);

777

846

}

778

847

break;

779

case 'P':

780

mc.priority = optarg;

781

break;

782

case '?':

848

case 130:

849

mc.priority = arg;

850

break;

851

case ARGP_KEY_ARG:

852

argp_usage (state);

853

break;

854

case ARGP_KEY_END:

855

break;

783

856

default:

784

/* getopt_long() has already printed a message about the

785

unrcognized option, so just exit. */

786

exit(EXIT_FAILURE);

857

return ARGP_ERR_UNKNOWN;

787

858

}

788

}

789

/* Set the global debug flag from the temporary int */

790

debug = debug_int ? true : false;

859

return 0;

860

}

861

862

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

863

.args_doc = "",

864

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

865

" passwords from mandos server" };

866

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

867

if (ret == ARGP_ERR_UNKNOWN){

868

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

869

exitcode = EXIT_FAILURE;

870

goto end;

871

}

791

872

}

792

873

793

874

pubkeyfile = combinepath(keydir, pubkeyfile);

794

875

if (pubkeyfile == NULL){

795

876

perror("combinepath");

800

881

seckeyfile = combinepath(keydir, seckeyfile);

801

882

if (seckeyfile == NULL){

802

883

perror("combinepath");

803

goto end;

884

exitcode = EXIT_FAILURE;

885

goto end;

886

}

887

888

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

889

if (ret == -1){

890

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

891

exitcode = EXIT_FAILURE;

892

goto end;

893

} else {

894

gnutls_initalized = true;

895

}

896

897

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

898

{

899

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

900

if(sd < 0) {

901

perror("socket");

902

exitcode = EXIT_FAILURE;

903

goto end;

904

}

905

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

906

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

907

if(ret == -1){

908

perror("ioctl SIOCGIFFLAGS");

909

exitcode = EXIT_FAILURE;

910

goto end;

911

}

912

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

913

network.ifr_flags |= IFF_UP;

914

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

915

if(ret == -1){

916

perror("ioctl SIOCSIFFLAGS");

917

exitcode = EXIT_FAILURE;

918

goto end;

919

}

920

}

921

close(sd);

922

}

923

924

uid = getuid();

925

gid = getgid();

926

927

ret = setuid(uid);

928

if (ret == -1){

929

perror("setuid");

930

}

931

932

setgid(gid);

933

if (ret == -1){

934

perror("setgid");

804

935

}

805

936

806

937

if_index = (AvahiIfIndex) if_nametoindex(interface);

815

946

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

816

947

if(address == NULL){

817

948

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

818

exit(EXIT_FAILURE);

949

exitcode = EXIT_FAILURE;

950

goto end;

819

951

}

820

952

errno = 0;

821

953

uint16_t port = (uint16_t) strtol(address+1, NULL, 10);

822

954

if(errno){

823

955

perror("Bad port number");

824

exit(EXIT_FAILURE);

956

exitcode = EXIT_FAILURE;

957

goto end;

825

958

}

826

959

*address = '\0';

827

960

address = connect_to;

828

961

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

829

962

if(ret < 0){

830

exit(EXIT_FAILURE);

963

exitcode = EXIT_FAILURE;

831

964

} else {

832

exit(EXIT_SUCCESS);

833

}

834

}

835

836

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

837

{

838

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

839

if(sd < 0) {

840

perror("socket");

841

exitcode = EXIT_FAILURE;

842

goto end;

843

}

844

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

845

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

846

if(ret == -1){

847

perror("ioctl SIOCGIFFLAGS");

848

exitcode = EXIT_FAILURE;

849

goto end;

850

}

851

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

852

network.ifr_flags |= IFF_UP;

853

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

854

if(ret == -1){

855

perror("ioctl SIOCSIFFLAGS");

856

exitcode = EXIT_FAILURE;

857

goto end;

858

}

859

}

860

close(sd);

965

exitcode = EXIT_SUCCESS;

966

}

967

goto end;

861

968

}

862

969

863

970

if (not debug){

939

1046

avahi_simple_poll_free(mc.simple_poll);

940

1047

free(pubkeyfile);

941

1048

free(seckeyfile);

1049

1050

if (gnutls_initalized){

1051

gnutls_certificate_free_credentials(mc.cred);

1052

gnutls_global_deinit ();

1053

}

942

1054

943

1055

return exitcode;

944

1056

}