/mandos/trunk : revision 24.1.141

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,

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;

531

char *decrypted_buffer;

548

532

size_t buffer_length = 0;

549

533

size_t buffer_capacity = 0;

550

534

size_t written;

551

int retval = -1;

535

int retval = 0;

552

536

gnutls_session_t session;

553

537

int pf; /* Protocol family */

554

538

581

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

582

566

if(tcp_sd < 0){

583

567

perror("socket");

568

retval = -1;

584

569

goto mandos_end;

585

570

}

586

571

598

583

}

599

584

if(ret < 0 ){

600

585

perror("inet_pton");

586

retval = -1;

601

587

goto mandos_end;

602

588

}

603

589

if(ret == 0){

604

590

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

591

retval = -1;

605

592

goto mandos_end;

606

593

}

607

594

if(af == AF_INET6){

615

602

if(if_index == AVAHI_IF_UNSPEC){

616

603

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

617

604

" without a network interface\n");

605

retval = -1;

618

606

goto mandos_end;

619

607

}

620

608

/* Set the network interface number as scope */

673

661

}

674

662

if(ret < 0){

675

663

perror("connect");

664

retval = -1;

676

665

goto mandos_end;

677

666

}

678

667

688

677

out_size - written));

689

678

if(ret == -1){

690

679

perror("write");

680

retval = -1;

691

681

goto mandos_end;

692

682

}

693

683

written += (size_t)ret;

733

723

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

734

724

gnutls_perror(ret);

735

725

}

726

retval = -1;

736

727

goto mandos_end;

737

728

}

738

729

753

744

buffer_capacity);

754

745

if(buffer_capacity == 0){

755

746

perror("incbuffer");

747

retval = -1;

756

748

goto mandos_end;

757

749

}

758

750

781

773

if(ret < 0){

782

774

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

783

775

gnutls_perror(ret);

776

retval = -1;

784

777

goto mandos_end;

785

778

}

786

779

break;

787

780

default:

788

781

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

789

782

" encrypted session with Mandos server\n");

783

retval = -1;

790

784

gnutls_bye(session, GNUTLS_SHUT_RDWR);

791

785

goto mandos_end;

792

786

}

803

797

goto mandos_end;

804

798

}

805

799

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);

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

802

if(quit_now){

803

goto mandos_end;

804

}

812

805

813

806

if(buffer_length > 0){

814

807

ssize_t decrypted_buffer_size;

831

824

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

832

825

strerror(errno));

833

826

}

834

goto mandos_end;

827

retval = -1;

828

break;

835

829

}

836

830

written += (size_t)ret;

837

831

}

838

retval = 0;

832

free(decrypted_buffer);

833

} else {

834

retval = -1;

839

835

}

836

} else {

837

retval = -1;

840

838

}

841

839

842

840

/* Shutdown procedure */

843

841

844

842

mandos_end:

845

free(decrypted_buffer);

846

843

free(buffer);

847

844

if(tcp_sd >= 0){

848

845

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

998

995

bool gpgme_initialized = false;

999

996

float delay = 2.5f;

1000

997

1001

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

998

struct sigaction old_sigterm_action;

1002

999

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1003

1000

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

1001

{

1026

1002

struct argp_option options[] = {

1027

1003

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

1211

1187

goto end;

1212

1188

}

1213

1189

1214

/* Re-raise priviliges */

1215

errno = 0;

1216

ret = seteuid(0);

1217

if(ret == -1){

1218

perror("seteuid");

1219

}

1220

1221

1190

#ifdef __linux__

1222

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1223

1192

messages to mess up the prompt */

1241

1210

}

1242

1211

}

1243

1212

#endif /* __linux__ */

1244

/* Lower privileges */

1245

errno = 0;

1246

ret = seteuid(uid);

1247

if(ret == -1){

1248

perror("seteuid");

1249

}

1250

1213

goto end;

1251

1214

}

1252

1215

strcpy(network.ifr_name, interface);

1262

1225

}

1263

1226

#endif /* __linux__ */

1264

1227

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

1268

if(ret == -1){

1269

perror("seteuid");

1270

}

1271

1228

goto end;

1272

1229

}

1273

1230

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

1286

1243

}

1287

1244

}

1288

1245

#endif /* __linux__ */

1289

/* Lower privileges */

1290

errno = 0;

1291

ret = seteuid(uid);

1292

if(ret == -1){

1293

perror("seteuid");

1294

}

1295

1246

goto end;

1296

1247

}

1297

1248

}

1325

1276

}

1326

1277

}

1327

1278

#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

}

1279

}

1280

1281

if(quit_now){

1282

goto end;

1283

}

1284

1285

uid = getuid();

1286

gid = getgid();

1287

1288

errno = 0;

1289

setgid(gid);

1290

if(ret == -1){

1291

perror("setgid");

1292

}

1293

1294

ret = setuid(uid);

1295

if(ret == -1){

1296

perror("setuid");

1343

1297

}

1344

1298

1345

1299

if(quit_now){

1519

1473

1520

1474

/* Take down the network interface */

1521

1475

if(take_down_interface){

1522

/* Re-raise priviliges */

1523

errno = 0;

1524

ret = seteuid(0);

1476

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

1525

1477

if(ret == -1){

1526

perror("seteuid");

1478

perror("ioctl SIOCGIFFLAGS");

1479

} else if(network.ifr_flags & IFF_UP) {

1480

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

1481

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

1482

if(ret == -1){

1483

perror("ioctl SIOCSIFFLAGS");

1484

}

1527

1485

}

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

}

1486

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

1487

if(ret == -1){

1488

perror("close");

1549

1489

}

1550

1490

}

1551

1491

1596

1536

if(quit_now){

1597

1537

sigemptyset(&old_sigterm_action.sa_mask);

1598

1538

old_sigterm_action.sa_handler = SIG_DFL;

1599

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1600

&old_sigterm_action,

1601

NULL));

1539

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

1602

1540

if(ret == -1){

1603

1541

perror("sigaction");

1604

1542

}

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());

1543

raise(signal_received);

1613

1544

}

1614

1545

1615

1546

return exitcode;