/mandos/trunk : revision 24.1.142

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() */

47

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

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(), setuid(),

75

setgid() */

74

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

75

setgid(), pause() */

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

145

148

/*

146

149

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

147

150

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

474

477

static int init_gnutls_session(gnutls_session_t *session){

475

478

int ret;

476

479

/* GnuTLS session creation */

477

ret = gnutls_init(session, GNUTLS_SERVER);

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);

478

486

if(ret != GNUTLS_E_SUCCESS){

479

487

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

480

488

safer_gnutls_strerror(ret));

482

490

483

491

{

484

492

const char *err;

485

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

486

500

if(ret != GNUTLS_E_SUCCESS){

487

501

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

488

502

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

492

506

}

493

507

}

494

508

495

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

496

mc.cred);

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);

497

517

if(ret != GNUTLS_E_SUCCESS){

498

518

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

499

519

safer_gnutls_strerror(ret));

502

522

}

503

523

504

524

/* ignore client certificate if any. */

505

gnutls_certificate_server_set_request(*session,

506

GNUTLS_CERT_IGNORE);

525

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

507

526

508

527

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

509

528

514

533

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

515

534

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

516

535

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

536

/* Called when a Mandos server is found */

521

537

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

522

538

AvahiIfIndex if_index,

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544

struct sockaddr_in6 in6;

529

545

} to;

530

546

char *buffer = NULL;

531

char *decrypted_buffer;

547

char *decrypted_buffer = NULL;

532

548

size_t buffer_length = 0;

533

549

size_t buffer_capacity = 0;

534

550

size_t written;

535

int retval = 0;

551

int retval = -1;

536

552

gnutls_session_t session;

537

553

int pf; /* Protocol family */

538

554

565

581

tcp_sd = socket(pf, SOCK_STREAM, 0);

566

582

if(tcp_sd < 0){

567

583

perror("socket");

568

retval = -1;

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584

goto mandos_end;

570

585

}

571

586

583

598

}

584

599

if(ret < 0 ){

585

600

perror("inet_pton");

586

retval = -1;

587

601

goto mandos_end;

588

602

}

589

603

if(ret == 0){

590

604

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

591

retval = -1;

592

605

goto mandos_end;

593

606

}

594

607

if(af == AF_INET6){

602

615

if(if_index == AVAHI_IF_UNSPEC){

603

616

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

604

617

" without a network interface\n");

605

retval = -1;

606

618

goto mandos_end;

607

619

}

608

620

/* Set the network interface number as scope */

661

673

}

662

674

if(ret < 0){

663

675

perror("connect");

664

retval = -1;

665

676

goto mandos_end;

666

677

}

667

678

677

688

out_size - written));

678

689

if(ret == -1){

679

690

perror("write");

680

retval = -1;

681

691

goto mandos_end;

682

692

}

683

693

written += (size_t)ret;

723

733

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

724

734

gnutls_perror(ret);

725

735

}

726

retval = -1;

727

736

goto mandos_end;

728

737

}

729

738

744

753

buffer_capacity);

745

754

if(buffer_capacity == 0){

746

755

perror("incbuffer");

747

retval = -1;

748

756

goto mandos_end;

749

757

}

750

758

773

781

if(ret < 0){

774

782

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

775

783

gnutls_perror(ret);

776

retval = -1;

777

784

goto mandos_end;

778

785

}

779

786

break;

780

787

default:

781

788

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

782

789

" encrypted session with Mandos server\n");

783

retval = -1;

784

790

gnutls_bye(session, GNUTLS_SHUT_RDWR);

785

791

goto mandos_end;

786

792

}

797

803

goto mandos_end;

798

804

}

799

805

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

802

if(quit_now){

803

goto mandos_end;

804

}

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);

805

812

806

813

if(buffer_length > 0){

807

814

ssize_t decrypted_buffer_size;

824

831

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

825

832

strerror(errno));

826

833

}

827

retval = -1;

828

break;

834

goto mandos_end;

829

835

}

830

836

written += (size_t)ret;

831

837

}

832

free(decrypted_buffer);

833

} else {

834

retval = -1;

838

retval = 0;

835

839

}

836

} else {

837

retval = -1;

838

840

}

839

841

840

842

/* Shutdown procedure */

841

843

842

844

mandos_end:

845

free(decrypted_buffer);

843

846

free(buffer);

844

847

if(tcp_sd >= 0){

845

848

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

995

998

bool gpgme_initialized = false;

996

999

float delay = 2.5f;

997

1000

998

struct sigaction old_sigterm_action;

1001

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

999

1002

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1000

1003

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

1001

1025

{

1002

1026

struct argp_option options[] = {

1003

1027

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

1187

1211

goto end;

1188

1212

}

1189

1213

1214

/* Re-raise priviliges */

1215

errno = 0;

1216

ret = seteuid(0);

1217

if(ret == -1){

1218

perror("seteuid");

1219

}

1220

1190

1221

#ifdef __linux__

1191

1222

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1192

1223

messages to mess up the prompt */

1210

1241

}

1211

1242

}

1212

1243

#endif /* __linux__ */

1244

/* Lower privileges */

1245

errno = 0;

1246

ret = seteuid(uid);

1247

if(ret == -1){

1248

perror("seteuid");

1249

}

1213

1250

goto end;

1214

1251

}

1215

1252

strcpy(network.ifr_name, interface);

1225

1262

}

1226

1263

#endif /* __linux__ */

1227

1264

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

1268

if(ret == -1){

1269

perror("seteuid");

1270

}

1228

1271

goto end;

1229

1272

}

1230

1273

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

1243

1286

}

1244

1287

}

1245

1288

#endif /* __linux__ */

1289

/* Lower privileges */

1290

errno = 0;

1291

ret = seteuid(uid);

1292

if(ret == -1){

1293

perror("seteuid");

1294

}

1246

1295

goto end;

1247

1296

}

1248

1297

}

1276

1325

}

1277

1326

}

1278

1327

#endif /* __linux__ */

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");

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

}

1297

1343

}

1298

1344

1299

1345

if(quit_now){

1473

1519

1474

1520

/* Take down the network interface */

1475

1521

if(take_down_interface){

1476

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

1522

/* Re-raise priviliges */

1523

errno = 0;

1524

ret = seteuid(0);

1477

1525

if(ret == -1){

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

}

1526

perror("seteuid");

1485

1527

}

1486

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

1487

if(ret == -1){

1488

perror("close");

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

}

1489

1549

}

1490

1550

}

1491

1551

1536

1596

if(quit_now){

1537

1597

sigemptyset(&old_sigterm_action.sa_mask);

1538

1598

old_sigterm_action.sa_handler = SIG_DFL;

1539

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

1599

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1600

&old_sigterm_action,

1601

NULL));

1540

1602

if(ret == -1){

1541

1603

perror("sigaction");

1542

1604

}

1543

raise(signal_received);

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());

1544

1613

}

1545

1614

1546

1615

return exitcode;