/mandos/trunk : revision 360

44

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

45

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

46

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

47

srand(), strtof(), abort() */

47

srand(), strtof() */

48

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

49

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

50

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

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

73

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

74

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

75

setgid(), pause() */

74

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

75

setgid() */

76

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

77

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

78

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

142

.dh_bits = 1024, .priority = "SECURE256"

143

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

144

145

sig_atomic_t quit_now = 0;

146

int signal_received = 0;

147

148

145

/*

149

146

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

150

147

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

167

164

*/

168

165

static bool init_gpgme(const char *seckey,

169

166

const char *pubkey, const char *tempdir){

167

int ret;

170

168

gpgme_error_t rc;

171

169

gpgme_engine_info_t engine_info;

172

170

175

173

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

176

174

*/

177

175

bool import_key(const char *filename){

178

int ret;

179

176

int fd;

180

177

gpgme_data_t pgp_data;

181

178

477

474

static int init_gnutls_session(gnutls_session_t *session){

478

475

int ret;

479

476

/* GnuTLS session creation */

480

do {

481

ret = gnutls_init(session, GNUTLS_SERVER);

482

if(quit_now){

483

return -1;

484

}

485

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

477

ret = gnutls_init(session, GNUTLS_SERVER);

486

478

if(ret != GNUTLS_E_SUCCESS){

487

479

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

488

480

safer_gnutls_strerror(ret));

490

482

491

483

{

492

484

const char *err;

493

do {

494

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

495

if(quit_now){

496

gnutls_deinit(*session);

497

return -1;

498

}

499

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

485

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

500

486

if(ret != GNUTLS_E_SUCCESS){

501

487

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

502

488

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

506

492

}

507

493

}

508

494

509

do {

510

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

511

mc.cred);

512

if(quit_now){

513

gnutls_deinit(*session);

514

return -1;

515

}

516

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

495

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

496

mc.cred);

517

497

if(ret != GNUTLS_E_SUCCESS){

518

498

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

519

499

safer_gnutls_strerror(ret));

522

502

}

523

503

524

504

/* ignore client certificate if any. */

525

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

505

gnutls_certificate_server_set_request(*session,

506

GNUTLS_CERT_IGNORE);

526

507

527

508

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

528

509

533

514

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

534

515

__attribute__((unused)) const char *txt){}

535

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

536

520

/* Called when a Mandos server is found */

537

521

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

538

522

AvahiIfIndex if_index,

544

528

struct sockaddr_in6 in6;

545

529

} to;

546

530

char *buffer = NULL;

547

char *decrypted_buffer = NULL;

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char *decrypted_buffer;

548

532

size_t buffer_length = 0;

549

533

size_t buffer_capacity = 0;

534

ssize_t decrypted_buffer_size;

550

535

size_t written;

551

int retval = -1;

536

int retval = 0;

552

537

gnutls_session_t session;

553

538

int pf; /* Protocol family */

554

539

581

566

tcp_sd = socket(pf, SOCK_STREAM, 0);

582

567

if(tcp_sd < 0){

583

568

perror("socket");

569

retval = -1;

584

570

goto mandos_end;

585

571

}

586

572

598

584

}

599

585

if(ret < 0 ){

600

586

perror("inet_pton");

587

retval = -1;

601

588

goto mandos_end;

602

589

}

603

590

if(ret == 0){

604

591

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

592

retval = -1;

605

593

goto mandos_end;

606

594

}

607

595

if(af == AF_INET6){

615

603

if(if_index == AVAHI_IF_UNSPEC){

616

604

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

617

605

" without a network interface\n");

606

retval = -1;

618

607

goto mandos_end;

619

608

}

620

609

/* Set the network interface number as scope */

673

662

}

674

663

if(ret < 0){

675

664

perror("connect");

665

retval = -1;

676

666

goto mandos_end;

677

667

}

678

668

688

678

out_size - written));

689

679

if(ret == -1){

690

680

perror("write");

681

retval = -1;

691

682

goto mandos_end;

692

683

}

693

684

written += (size_t)ret;

721

712

goto mandos_end;

722

713

}

723

714

724

do {

715

do{

725

716

ret = gnutls_handshake(session);

726

717

if(quit_now){

727

718

goto mandos_end;

733

724

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

734

725

gnutls_perror(ret);

735

726

}

727

retval = -1;

736

728

goto mandos_end;

737

729

}

738

730

753

745

buffer_capacity);

754

746

if(buffer_capacity == 0){

755

747

perror("incbuffer");

748

retval = -1;

756

749

goto mandos_end;

757

750

}

758

751

771

764

case GNUTLS_E_AGAIN:

772

765

break;

773

766

case GNUTLS_E_REHANDSHAKE:

774

do {

767

do{

775

768

ret = gnutls_handshake(session);

776

769

777

770

if(quit_now){

781

774

if(ret < 0){

782

775

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

783

776

gnutls_perror(ret);

777

retval = -1;

784

778

goto mandos_end;

785

779

}

786

780

break;

787

781

default:

788

782

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

789

783

" encrypted session with Mandos server\n");

784

retval = -1;

790

785

gnutls_bye(session, GNUTLS_SHUT_RDWR);

791

786

goto mandos_end;

792

787

}

803

798

goto mandos_end;

804

799

}

805

800

806

do {

807

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

808

if(quit_now){

809

goto mandos_end;

810

}

811

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

801

gnutls_bye(session, GNUTLS_SHUT_RDWR);

802

803

if(quit_now){

804

goto mandos_end;

805

}

812

806

813

807

if(buffer_length > 0){

814

ssize_t decrypted_buffer_size;

815

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

816

809

buffer_length,

817

810

&decrypted_buffer);

818

811

if(decrypted_buffer_size >= 0){

819

820

812

written = 0;

821

813

while(written < (size_t) decrypted_buffer_size){

822

814

if(quit_now){

831

823

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

832

824

strerror(errno));

833

825

}

834

goto mandos_end;

826

retval = -1;

827

break;

835

828

}

836

829

written += (size_t)ret;

837

830

}

838

retval = 0;

831

free(decrypted_buffer);

832

} else {

833

retval = -1;

839

834

}

835

} else {

836

retval = -1;

840

837

}

841

838

842

839

/* Shutdown procedure */

843

840

844

841

mandos_end:

845

free(decrypted_buffer);

846

842

free(buffer);

847

843

if(tcp_sd >= 0){

848

844

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

998

994

bool gpgme_initialized = false;

999

995

float delay = 2.5f;

1000

996

1001

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

997

struct sigaction old_sigterm_action;

1002

998

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1003

999

1004

uid = getuid();

1005

gid = getgid();

1006

1007

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

1008

errno = 0;

1009

ret = setgid(gid);

1010

if(ret == -1){

1011

perror("setgid");

1012

}

1013

1014

/* Lower user privileges (temporarily) */

1015

errno = 0;

1016

ret = seteuid(uid);

1017

if(ret == -1){

1018

perror("seteuid");

1019

}

1020

1021

if(quit_now){

1022

goto end;

1023

}

1024

1025

1000

{

1026

1001

struct argp_option options[] = {

1027

1002

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

1211

1186

goto end;

1212

1187

}

1213

1188

1214

/* Re-raise priviliges */

1215

errno = 0;

1216

ret = seteuid(0);

1217

if(ret == -1){

1218

perror("seteuid");

1219

}

1220

1221

1189

#ifdef __linux__

1222

1190

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1223

1191

messages to mess up the prompt */

1241

1209

}

1242

1210

}

1243

1211

#endif /* __linux__ */

1244

/* Lower privileges */

1245

errno = 0;

1246

ret = seteuid(uid);

1247

if(ret == -1){

1248

perror("seteuid");

1249

}

1250

1212

goto end;

1251

1213

}

1252

1214

strcpy(network.ifr_name, interface);

1262

1224

}

1263

1225

#endif /* __linux__ */

1264

1226

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

1268

if(ret == -1){

1269

perror("seteuid");

1270

}

1271

1227

goto end;

1272

1228

}

1273

1229

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

1286

1242

}

1287

1243

}

1288

1244

#endif /* __linux__ */

1289

/* Lower privileges */

1290

errno = 0;

1291

ret = seteuid(uid);

1292

if(ret == -1){

1293

perror("seteuid");

1294

}

1295

1245

goto end;

1296

1246

}

1297

1247

}

1325

1275

}

1326

1276

}

1327

1277

#endif /* __linux__ */

1328

/* Lower privileges */

1329

errno = 0;

1330

if(take_down_interface){

1331

/* Lower privileges */

1332

ret = seteuid(uid);

1333

if(ret == -1){

1334

perror("seteuid");

1335

}

1336

} else {

1337

/* Lower privileges permanently */

1338

ret = setuid(uid);

1339

if(ret == -1){

1340

perror("setuid");

1341

}

1342

}

1278

}

1279

1280

if(quit_now){

1281

goto end;

1282

}

1283

1284

uid = getuid();

1285

gid = getgid();

1286

1287

errno = 0;

1288

setgid(gid);

1289

if(ret == -1){

1290

perror("setgid");

1291

}

1292

1293

ret = setuid(uid);

1294

if(ret == -1){

1295

perror("setuid");

1343

1296

}

1344

1297

1345

1298

if(quit_now){

1519

1472

1520

1473

/* Take down the network interface */

1521

1474

if(take_down_interface){

1522

/* Re-raise priviliges */

1523

errno = 0;

1524

ret = seteuid(0);

1475

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

1525

1476

if(ret == -1){

1526

perror("seteuid");

1477

perror("ioctl SIOCGIFFLAGS");

1478

} else if(network.ifr_flags & IFF_UP) {

1479

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

1480

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

1481

if(ret == -1){

1482

perror("ioctl SIOCSIFFLAGS");

1483

}

1527

1484

}

1528

if(geteuid() == 0){

1529

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

1530

if(ret == -1){

1531

perror("ioctl SIOCGIFFLAGS");

1532

} else if(network.ifr_flags & IFF_UP) {

1533

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

1534

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

1535

if(ret == -1){

1536

perror("ioctl SIOCSIFFLAGS");

1537

}

1538

}

1539

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

1540

if(ret == -1){

1541

perror("close");

1542

}

1543

/* Lower privileges permanently */

1544

errno = 0;

1545

ret = setuid(uid);

1546

if(ret == -1){

1547

perror("setuid");

1548

}

1485

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

1486

if(ret == -1){

1487

perror("close");

1549

1488

}

1550

1489

}

1551

1490

1596

1535

if(quit_now){

1597

1536

sigemptyset(&old_sigterm_action.sa_mask);

1598

1537

old_sigterm_action.sa_handler = SIG_DFL;

1599

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1600

&old_sigterm_action,

1601

NULL));

1538

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

1602

1539

if(ret == -1){

1603

1540

perror("sigaction");

1604

1541

}

1605

do {

1606

ret = raise(signal_received);

1607

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

1608

if(ret != 0){

1609

perror("raise");

1610

abort();

1611

}

1612

TEMP_FAILURE_RETRY(pause());

1542

raise(signal_received);

1613

1543

}

1614

1544

1615

1545

return exitcode;