/mandos/trunk : revision 355

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,

539

523

int af){

540

int ret, tcp_sd = -1;

524

int ret, tcp_sd;

541

525

ssize_t sret;

542

526

union {

543

527

struct sockaddr_in in;

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;

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

555

if(quit_now){

556

return -1;

557

}

558

559

540

switch(af){

560

541

case AF_INET6:

561

542

pf = PF_INET6;

581

562

tcp_sd = socket(pf, SOCK_STREAM, 0);

582

563

if(tcp_sd < 0){

583

564

perror("socket");

584

goto mandos_end;

585

}

586

587

if(quit_now){

588

goto mandos_end;

565

return -1;

589

566

}

590

567

591

568

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

598

575

}

599

576

if(ret < 0 ){

600

577

perror("inet_pton");

601

goto mandos_end;

578

return -1;

602

579

}

603

580

if(ret == 0){

604

581

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

605

goto mandos_end;

582

return -1;

606

583

}

607

584

if(af == AF_INET6){

608

585

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

615

592

if(if_index == AVAHI_IF_UNSPEC){

616

593

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

617

594

" without a network interface\n");

618

goto mandos_end;

595

return -1;

619

596

}

620

597

/* Set the network interface number as scope */

621

598

to.in6.sin6_scope_id = (uint32_t)if_index;

626

603

-Wunreachable-code */

627

604

}

628

605

629

if(quit_now){

630

goto mandos_end;

631

}

632

633

606

if(debug){

634

607

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

635

608

char interface[IF_NAMESIZE];

662

635

}

663

636

}

664

637

665

if(quit_now){

666

goto mandos_end;

667

}

668

669

638

if(af == AF_INET6){

670

639

ret = connect(tcp_sd, &to.in6, sizeof(to));

671

640

} else {

673

642

}

674

643

if(ret < 0){

675

644

perror("connect");

676

goto mandos_end;

677

}

678

679

if(quit_now){

680

goto mandos_end;

645

return -1;

681

646

}

682

647

683

648

const char *out = mandos_protocol_version;

688

653

out_size - written));

689

654

if(ret == -1){

690

655

perror("write");

656

retval = -1;

691

657

goto mandos_end;

692

658

}

693

659

written += (size_t)ret;

701

667

break;

702

668

}

703

669

}

704

705

if(quit_now){

706

goto mandos_end;

707

}

708

670

}

709

671

710

672

if(debug){

711

673

fprintf(stderr, "Establishing TLS session with %s\n", ip);

712

674

}

713

675

714

if(quit_now){

715

goto mandos_end;

716

}

717

718

676

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

719

677

720

if(quit_now){

721

goto mandos_end;

722

}

723

724

do {

678

do{

725

679

ret = gnutls_handshake(session);

726

if(quit_now){

727

goto mandos_end;

728

}

729

680

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

730

681

731

682

if(ret != GNUTLS_E_SUCCESS){

733

684

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

734

685

gnutls_perror(ret);

735

686

}

687

retval = -1;

736

688

goto mandos_end;

737

689

}

738

690

744

696

}

745

697

746

698

while(true){

747

748

if(quit_now){

749

goto mandos_end;

750

}

751

752

699

buffer_capacity = incbuffer(&buffer, buffer_length,

753

700

buffer_capacity);

754

701

if(buffer_capacity == 0){

755

702

perror("incbuffer");

756

goto mandos_end;

757

}

758

759

if(quit_now){

703

retval = -1;

760

704

goto mandos_end;

761

705

}

762

706

771

715

case GNUTLS_E_AGAIN:

772

716

break;

773

717

case GNUTLS_E_REHANDSHAKE:

774

do {

718

do{

775

719

ret = gnutls_handshake(session);

776

777

if(quit_now){

778

goto mandos_end;

779

}

780

720

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

781

721

if(ret < 0){

782

722

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

783

723

gnutls_perror(ret);

724

retval = -1;

784

725

goto mandos_end;

785

726

}

786

727

break;

787

728

default:

788

729

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

789

730

" encrypted session with Mandos server\n");

731

retval = -1;

790

732

gnutls_bye(session, GNUTLS_SHUT_RDWR);

791

733

goto mandos_end;

792

734

}

799

741

fprintf(stderr, "Closing TLS session\n");

800

742

}

801

743

802

if(quit_now){

803

goto mandos_end;

804

}

805

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);

744

gnutls_bye(session, GNUTLS_SHUT_RDWR);

812

745

813

746

if(buffer_length > 0){

814

ssize_t decrypted_buffer_size;

815

747

decrypted_buffer_size = pgp_packet_decrypt(buffer,

816

748

buffer_length,

817

749

&decrypted_buffer);

818

750

if(decrypted_buffer_size >= 0){

819

820

751

written = 0;

821

752

while(written < (size_t) decrypted_buffer_size){

822

if(quit_now){

823

goto mandos_end;

824

}

825

826

753

ret = (int)fwrite(decrypted_buffer + written, 1,

827

754

(size_t)decrypted_buffer_size - written,

828

755

stdout);

831

758

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

832

759

strerror(errno));

833

760

}

834

goto mandos_end;

761

retval = -1;

762

break;

835

763

}

836

764

written += (size_t)ret;

837

765

}

838

retval = 0;

766

free(decrypted_buffer);

767

} else {

768

retval = -1;

839

769

}

770

} else {

771

retval = -1;

840

772

}

841

773

842

774

/* Shutdown procedure */

843

775

844

776

mandos_end:

845

free(decrypted_buffer);

846

777

free(buffer);

847

if(tcp_sd >= 0){

848

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

849

}

778

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

850

779

if(ret == -1){

851

780

perror("close");

852

781

}

853

782

gnutls_deinit(session);

854

if(quit_now){

855

retval = -1;

856

}

857

783

return retval;

858

784

}

859

785

922

848

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

923

849

is removed from the LAN */

924

850

925

if(quit_now){

926

return;

927

}

928

929

851

switch(event){

930

852

default:

931

853

case AVAHI_BROWSER_FAILURE:

998

920

bool gpgme_initialized = false;

999

921

float delay = 2.5f;

1000

922

1001

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

923

struct sigaction old_sigterm_action;

1002

924

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1003

925

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

926

{

1026

927

struct argp_option options[] = {

1027

928

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

1154

1055

exitcode = EXIT_FAILURE;

1155

1056

goto end;

1156

1057

}

1157

/* Need to check if the handler is SIG_IGN before handling:

1158

| [[info:libc:Initial Signal Actions]] |

1159

| [[info:libc:Basic Signal Handling]] |

1160

*/

1161

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

1162

if(ret == -1){

1163

perror("sigaction");

1164

return EXIT_FAILURE;

1165

}

1166

if(old_sigterm_action.sa_handler != SIG_IGN){

1167

ret = sigaction(SIGINT, &sigterm_action, NULL);

1168

if(ret == -1){

1169

perror("sigaction");

1170

exitcode = EXIT_FAILURE;

1171

goto end;

1172

}

1173

}

1174

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

1175

if(ret == -1){

1176

perror("sigaction");

1177

return EXIT_FAILURE;

1178

}

1179

if(old_sigterm_action.sa_handler != SIG_IGN){

1180

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1181

if(ret == -1){

1182

perror("sigaction");

1183

exitcode = EXIT_FAILURE;

1184

goto end;

1185

}

1186

}

1187

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

1188

if(ret == -1){

1189

perror("sigaction");

1190

return EXIT_FAILURE;

1191

}

1192

if(old_sigterm_action.sa_handler != SIG_IGN){

1193

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1194

if(ret == -1){

1195

perror("sigaction");

1196

exitcode = EXIT_FAILURE;

1197

goto end;

1198

}

1058

ret = sigaction(SIGINT, &sigterm_action, &old_sigterm_action);

1059

if(ret == -1){

1060

perror("sigaction");

1061

exitcode = EXIT_FAILURE;

1062

goto end;

1063

}

1064

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1065

if(ret == -1){

1066

perror("sigaction");

1067

exitcode = EXIT_FAILURE;

1068

goto end;

1069

}

1070

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1071

if(ret == -1){

1072

perror("sigaction");

1073

exitcode = EXIT_FAILURE;

1074

goto end;

1199

1075

}

1200

1076

1201

1077

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

1211

1087

goto end;

1212

1088

}

1213

1089

1214

/* Re-raise priviliges */

1215

errno = 0;

1216

ret = seteuid(0);

1217

if(ret == -1){

1218

perror("seteuid");

1219

}

1220

1221

1090

#ifdef __linux__

1222

1091

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1223

1092

messages to mess up the prompt */

1241

1110

}

1242

1111

}

1243

1112

#endif /* __linux__ */

1244

/* Lower privileges */

1245

errno = 0;

1246

ret = seteuid(uid);

1247

if(ret == -1){

1248

perror("seteuid");

1249

}

1250

1113

goto end;

1251

1114

}

1252

1115

strcpy(network.ifr_name, interface);

1262

1125

}

1263

1126

#endif /* __linux__ */

1264

1127

exitcode = EXIT_FAILURE;

1265

/* Lower privileges */

1266

errno = 0;

1267

ret = seteuid(uid);

1268

if(ret == -1){

1269

perror("seteuid");

1270

}

1271

1128

goto end;

1272

1129

}

1273

1130

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

1286

1143

}

1287

1144

}

1288

1145

#endif /* __linux__ */

1289

/* Lower privileges */

1290

errno = 0;

1291

ret = seteuid(uid);

1292

if(ret == -1){

1293

perror("seteuid");

1294

}

1295

1146

goto end;

1296

1147

}

1297

1148

}

1325

1176

}

1326

1177

}

1327

1178

#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

}

1179

}

1180

1181

if(quit_now){

1182

goto end;

1183

}

1184

1185

uid = getuid();

1186

gid = getgid();

1187

1188

errno = 0;

1189

setgid(gid);

1190

if(ret == -1){

1191

perror("setgid");

1192

}

1193

1194

ret = setuid(uid);

1195

if(ret == -1){

1196

perror("setuid");

1343

1197

}

1344

1198

1345

1199

if(quit_now){

1519

1373

1520

1374

/* Take down the network interface */

1521

1375

if(take_down_interface){

1522

/* Re-raise priviliges */

1523

errno = 0;

1524

ret = seteuid(0);

1376

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

1525

1377

if(ret == -1){

1526

perror("seteuid");

1378

perror("ioctl SIOCGIFFLAGS");

1379

} else if(network.ifr_flags & IFF_UP) {

1380

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

1381

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

1382

if(ret == -1){

1383

perror("ioctl SIOCSIFFLAGS");

1384

}

1527

1385

}

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

}

1386

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

1387

if(ret == -1){

1388

perror("close");

1549

1389

}

1550

1390

}

1551

1391

1594

1434

}

1595

1435

1596

1436

if(quit_now){

1597

sigemptyset(&old_sigterm_action.sa_mask);

1598

old_sigterm_action.sa_handler = SIG_DFL;

1599

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1600

&old_sigterm_action,

1601

NULL));

1437

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

1602

1438

if(ret == -1){

1603

1439

perror("sigaction");

1604

1440

}

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());

1441

raise(signal_received);

1613

1442

}

1614

1443

1615

1444

return exitcode;