/mandos/trunk : revision 316

30

*/

31

32

/* Needed by GPGME, specifically gpgme_data_seek() */

33

#ifndef _LARGEFILE_SOURCE

34

33

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

34

#define _FILE_OFFSET_BITS 64

38

#endif

39

35

40

36

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

37

71

67

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

68

*/

73

69

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

74

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

70

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

75

71

setgid() */

76

72

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

77

73

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

80

76

argp_parse(), ARGP_KEY_ARG,

81

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

78

#include <signal.h> /* sigemptyset(), sigaddset(),

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

79

sigaction(), SIGTERM, sigaction,

80

sig_atomic_t */

85

81

86

82

#ifdef __linux__

87

83

#include <sys/klog.h> /* klogctl() */

164

160

*/

165

161

static bool init_gpgme(const char *seckey,

166

162

const char *pubkey, const char *tempdir){

163

int ret;

167

164

gpgme_error_t rc;

168

165

gpgme_engine_info_t engine_info;

169

166

172

169

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

173

170

*/

174

171

bool import_key(const char *filename){

175

int ret;

176

172

int fd;

177

173

gpgme_data_t pgp_data;

178

174

249

245

return false;

250

246

}

251

247

252

return true;

248

return true;

253

249

}

254

250

255

251

/*

309

305

}

310

306

gpgme_recipient_t recipient;

311

307

recipient = result->recipients;

312

while(recipient != NULL){

313

fprintf(stderr, "Public key algorithm: %s\n",

314

gpgme_pubkey_algo_name(recipient->pubkey_algo));

315

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

316

fprintf(stderr, "Secret key available: %s\n",

317

recipient->status == GPG_ERR_NO_SECKEY

318

? "No" : "Yes");

319

recipient = recipient->next;

308

if(recipient){

309

while(recipient != NULL){

310

fprintf(stderr, "Public key algorithm: %s\n",

311

gpgme_pubkey_algo_name(recipient->pubkey_algo));

312

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

313

fprintf(stderr, "Secret key available: %s\n",

314

recipient->status == GPG_ERR_NO_SECKEY

315

? "No" : "Yes");

316

recipient = recipient->next;

317

}

320

318

}

321

319

}

322

320

}

474

472

static int init_gnutls_session(gnutls_session_t *session){

475

473

int ret;

476

474

/* GnuTLS session creation */

477

do {

478

ret = gnutls_init(session, GNUTLS_SERVER);

479

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

475

ret = gnutls_init(session, GNUTLS_SERVER);

480

476

if(ret != GNUTLS_E_SUCCESS){

481

477

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

482

478

safer_gnutls_strerror(ret));

484

480

485

481

{

486

482

const char *err;

487

do {

488

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

489

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

483

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

490

484

if(ret != GNUTLS_E_SUCCESS){

491

485

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

492

486

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

496

490

}

497

491

}

498

492

499

do {

500

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

501

mc.cred);

502

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

493

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

494

mc.cred);

503

495

if(ret != GNUTLS_E_SUCCESS){

504

496

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

505

497

safer_gnutls_strerror(ret));

508

500

}

509

501

510

502

/* ignore client certificate if any. */

511

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

503

gnutls_certificate_server_set_request(*session,

504

GNUTLS_CERT_IGNORE);

512

505

513

506

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

514

507

519

512

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

520

513

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

521

514

522

sig_atomic_t quit_now = 0;

523

int signal_received = 0;

524

525

515

/* Called when a Mandos server is found */

526

516

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

527

517

AvahiIfIndex if_index,

528

518

int af){

529

int ret, tcp_sd = -1;

519

int ret, tcp_sd;

530

520

ssize_t sret;

531

521

union {

532

522

struct sockaddr_in in;

536

526

char *decrypted_buffer;

537

527

size_t buffer_length = 0;

538

528

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

539

530

size_t written;

540

531

int retval = 0;

541

532

gnutls_session_t session;

542

533

int pf; /* Protocol family */

543

534

544

if(quit_now){

545

return -1;

546

}

547

548

535

switch(af){

549

536

case AF_INET6:

550

537

pf = PF_INET6;

570

557

tcp_sd = socket(pf, SOCK_STREAM, 0);

571

558

if(tcp_sd < 0){

572

559

perror("socket");

573

retval = -1;

574

goto mandos_end;

575

}

576

577

if(quit_now){

578

goto mandos_end;

560

return -1;

579

561

}

580

562

581

563

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

582

564

if(af == AF_INET6){

583

to.in6.sin6_family = (sa_family_t)af;

565

to.in6.sin6_family = (uint16_t)af;

584

566

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

585

567

} else { /* IPv4 */

586

568

to.in.sin_family = (sa_family_t)af;

588

570

}

589

571

if(ret < 0 ){

590

572

perror("inet_pton");

591

retval = -1;

592

goto mandos_end;

573

return -1;

593

574

}

594

575

if(ret == 0){

595

576

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

596

retval = -1;

597

goto mandos_end;

577

return -1;

598

578

}

599

579

if(af == AF_INET6){

600

580

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

607

587

if(if_index == AVAHI_IF_UNSPEC){

608

588

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

609

589

" without a network interface\n");

610

retval = -1;

611

goto mandos_end;

590

return -1;

612

591

}

613

592

/* Set the network interface number as scope */

614

593

to.in6.sin6_scope_id = (uint32_t)if_index;

619

598

-Wunreachable-code */

620

599

}

621

600

622

if(quit_now){

623

goto mandos_end;

624

}

625

626

601

if(debug){

627

602

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

628

603

char interface[IF_NAMESIZE];

655

630

}

656

631

}

657

632

658

if(quit_now){

659

goto mandos_end;

660

}

661

662

633

if(af == AF_INET6){

663

634

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

664

635

} else {

666

637

}

667

638

if(ret < 0){

668

639

perror("connect");

669

retval = -1;

670

goto mandos_end;

671

}

672

673

if(quit_now){

674

goto mandos_end;

640

return -1;

675

641

}

676

642

677

643

const char *out = mandos_protocol_version;

696

662

break;

697

663

}

698

664

}

699

700

if(quit_now){

701

goto mandos_end;

702

}

703

665

}

704

666

705

667

if(debug){

706

668

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

707

669

}

708

670

709

if(quit_now){

710

goto mandos_end;

711

}

712

713

671

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

714

672

715

if(quit_now){

716

goto mandos_end;

717

}

718

719

do {

673

do{

720

674

ret = gnutls_handshake(session);

721

if(quit_now){

722

goto mandos_end;

723

}

724

675

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

725

676

726

677

if(ret != GNUTLS_E_SUCCESS){

740

691

}

741

692

742

693

while(true){

743

744

if(quit_now){

745

goto mandos_end;

746

}

747

748

694

buffer_capacity = incbuffer(&buffer, buffer_length,

749

695

buffer_capacity);

750

696

if(buffer_capacity == 0){

753

699

goto mandos_end;

754

700

}

755

701

756

if(quit_now){

757

goto mandos_end;

758

}

759

760

702

sret = gnutls_record_recv(session, buffer+buffer_length,

761

703

BUFFER_SIZE);

762

704

if(sret == 0){

768

710

case GNUTLS_E_AGAIN:

769

711

break;

770

712

case GNUTLS_E_REHANDSHAKE:

771

do {

713

do{

772

714

ret = gnutls_handshake(session);

773

774

if(quit_now){

775

goto mandos_end;

776

}

777

715

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

778

716

if(ret < 0){

779

717

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

798

736

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

799

737

}

800

738

801

if(quit_now){

802

goto mandos_end;

803

}

804

805

739

gnutls_bye(session, GNUTLS_SHUT_RDWR);

806

740

807

if(quit_now){

808

goto mandos_end;

809

}

810

811

741

if(buffer_length > 0){

812

ssize_t decrypted_buffer_size;

813

742

decrypted_buffer_size = pgp_packet_decrypt(buffer,

814

743

buffer_length,

815

744

&decrypted_buffer);

816

745

if(decrypted_buffer_size >= 0){

817

818

746

written = 0;

819

747

while(written < (size_t) decrypted_buffer_size){

820

if(quit_now){

821

goto mandos_end;

822

}

823

824

748

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

825

749

(size_t)decrypted_buffer_size - written,

826

750

stdout);

846

770

847

771

mandos_end:

848

772

free(buffer);

849

if(tcp_sd >= 0){

850

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

851

}

773

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

852

774

if(ret == -1){

853

775

perror("close");

854

776

}

855

777

gnutls_deinit(session);

856

if(quit_now){

857

retval = -1;

858

}

859

778

return retval;

860

779

}

861

780

878

797

/* Called whenever a service has been resolved successfully or

879

798

timed out */

880

799

881

if(quit_now){

882

return;

883

}

884

885

800

switch(event){

886

801

default:

887

802

case AVAHI_RESOLVER_FAILURE:

924

839

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

925

840

is removed from the LAN */

926

841

927

if(quit_now){

928

return;

929

}

930

931

842

switch(event){

932

843

default:

933

844

case AVAHI_BROWSER_FAILURE:

962

873

}

963

874

}

964

875

876

sig_atomic_t quit_now = 0;

877

965

878

/* stop main loop after sigterm has been called */

966

static void handle_sigterm(int sig){

879

static void handle_sigterm(__attribute__((unused)) int sig){

967

880

if(quit_now){

968

881

return;

969

882

}

970

883

quit_now = 1;

971

signal_received = sig;

972

884

int old_errno = errno;

973

885

if(mc.simple_poll != NULL){

974

886

avahi_simple_poll_quit(mc.simple_poll);

985

897

int exitcode = EXIT_SUCCESS;

986

898

const char *interface = "eth0";

987

899

struct ifreq network;

988

int sd = -1;

989

bool take_down_interface = false;

900

int sd;

990

901

uid_t uid;

991

902

gid_t gid;

992

903

char *connect_to = NULL;

1003

914

struct sigaction old_sigterm_action;

1004

915

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1005

916

1006

uid = getuid();

1007

gid = getgid();

1008

1009

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

1010

errno = 0;

1011

ret = setgid(gid);

1012

if(ret == -1){

1013

perror("setgid");

1014

}

1015

1016

/* Lower user privileges (temporarily) */

1017

errno = 0;

1018

ret = seteuid(uid);

1019

if(ret == -1){

1020

perror("seteuid");

1021

}

1022

1023

if(quit_now){

1024

goto end;

1025

}

1026

1027

917

{

1028

918

struct argp_option options[] = {

1029

919

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

1156

1046

exitcode = EXIT_FAILURE;

1157

1047

goto end;

1158

1048

}

1159

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

1160

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

1161

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

1162

*/

1163

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

1164

if(ret == -1){

1165

perror("sigaction");

1166

return EXIT_FAILURE;

1167

}

1168

if(old_sigterm_action.sa_handler != SIG_IGN){

1169

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

1170

if(ret == -1){

1171

perror("sigaction");

1172

exitcode = EXIT_FAILURE;

1173

goto end;

1174

}

1175

}

1176

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

1177

if(ret == -1){

1178

perror("sigaction");

1179

return EXIT_FAILURE;

1180

}

1181

if(old_sigterm_action.sa_handler != SIG_IGN){

1182

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

1183

if(ret == -1){

1184

perror("sigaction");

1185

exitcode = EXIT_FAILURE;

1186

goto end;

1187

}

1188

}

1189

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

1190

if(ret == -1){

1191

perror("sigaction");

1192

return EXIT_FAILURE;

1193

}

1194

if(old_sigterm_action.sa_handler != SIG_IGN){

1195

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

1196

if(ret == -1){

1197

perror("sigaction");

1198

exitcode = EXIT_FAILURE;

1199

goto end;

1200

}

1201

}

1049

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

1050

if(ret == -1){

1051

perror("sigaction");

1052

exitcode = EXIT_FAILURE;

1053

goto end;

1054

}

1202

1055

1203

1056

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

1204

1057

if(interface[0] != '\0'){

1205

if_index = (AvahiIfIndex) if_nametoindex(interface);

1206

if(if_index == 0){

1207

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1208

exitcode = EXIT_FAILURE;

1209

goto end;

1210

}

1211

1212

if(quit_now){

1213

goto end;

1214

}

1215

1216

/* Re-raise priviliges */

1217

errno = 0;

1218

ret = seteuid(0);

1219

if(ret == -1){

1220

perror("seteuid");

1221

}

1222

1223

1058

#ifdef __linux__

1224

1059

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1225

1060

messages to mess up the prompt */

1243

1078

}

1244

1079

}

1245

1080

#endif /* __linux__ */

1246

/* Lower privileges */

1247

errno = 0;

1248

ret = seteuid(uid);

1249

if(ret == -1){

1250

perror("seteuid");

1251

}

1252

1081

goto end;

1253

1082

}

1254

1083

strcpy(network.ifr_name, interface);

1264

1093

}

1265

1094

#endif /* __linux__ */

1266

1095

exitcode = EXIT_FAILURE;

1267

/* Lower privileges */

1268

errno = 0;

1269

ret = seteuid(uid);

1270

if(ret == -1){

1271

perror("seteuid");

1272

}

1273

1096

goto end;

1274

1097

}

1275

1098

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

1276

1099

network.ifr_flags |= IFF_UP;

1277

take_down_interface = true;

1278

1100

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

1279

1101

if(ret == -1){

1280

take_down_interface = false;

1281

1102

perror("ioctl SIOCSIFFLAGS");

1282

1103

exitcode = EXIT_FAILURE;

1283

1104

#ifdef __linux__

1288

1109

}

1289

1110

}

1290

1111

#endif /* __linux__ */

1291

/* Lower privileges */

1292

errno = 0;

1293

ret = seteuid(uid);

1294

if(ret == -1){

1295

perror("seteuid");

1296

}

1297

1112

goto end;

1298

1113

}

1299

1114

}

1311

1126

perror("nanosleep");

1312

1127

}

1313

1128

}

1314

if(not take_down_interface){

1315

/* We won't need the socket anymore */

1316

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

1317

if(ret == -1){

1318

perror("close");

1319

}

1129

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

1130

if(ret == -1){

1131

perror("close");

1320

1132

}

1321

1133

#ifdef __linux__

1322

1134

if(restore_loglevel){

1327

1139

}

1328

1140

}

1329

1141

#endif /* __linux__ */

1330

/* Lower privileges */

1331

errno = 0;

1332

if(take_down_interface){

1333

/* Lower privileges */

1334

ret = seteuid(uid);

1335

if(ret == -1){

1336

perror("seteuid");

1337

}

1338

} else {

1339

/* Lower privileges permanently */

1340

ret = setuid(uid);

1341

if(ret == -1){

1342

perror("setuid");

1343

}

1344

}

1345

}

1346

1347

if(quit_now){

1348

goto end;

1142

}

1143

1144

uid = getuid();

1145

gid = getgid();

1146

1147

errno = 0;

1148

setgid(gid);

1149

if(ret == -1){

1150

perror("setgid");

1151

}

1152

1153

ret = setuid(uid);

1154

if(ret == -1){

1155

perror("setuid");

1349

1156

}

1350

1157

1351

1158

ret = init_gnutls_global(pubkey, seckey);

1357

1164

gnutls_initialized = true;

1358

1165

}

1359

1166

1360

if(quit_now){

1361

goto end;

1362

}

1363

1364

tempdir_created = true;

1365

1167

if(mkdtemp(tempdir) == NULL){

1366

tempdir_created = false;

1367

1168

perror("mkdtemp");

1368

1169

goto end;

1369

1170

}

1370

1371

if(quit_now){

1372

goto end;

1373

}

1171

tempdir_created = true;

1374

1172

1375

1173

if(not init_gpgme(pubkey, seckey, tempdir)){

1376

1174

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

1380

1178

gpgme_initialized = true;

1381

1179

}

1382

1180

1383

if(quit_now){

1384

goto end;

1181

if(interface[0] != '\0'){

1182

if_index = (AvahiIfIndex) if_nametoindex(interface);

1183

if(if_index == 0){

1184

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1185

exitcode = EXIT_FAILURE;

1186

goto end;

1187

}

1385

1188

}

1386

1189

1387

1190

if(connect_to != NULL){

1393

1196

exitcode = EXIT_FAILURE;

1394

1197

goto end;

1395

1198

}

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1401

1199

uint16_t port;

1402

1200

errno = 0;

1403

1201

tmpmax = strtoimax(address+1, &tmp, 10);

1407

1205

exitcode = EXIT_FAILURE;

1408

1206

goto end;

1409

1207

}

1410

1411

if(quit_now){

1412

goto end;

1413

}

1414

1415

1208

port = (uint16_t)tmpmax;

1416

1209

*address = '\0';

1417

1210

address = connect_to;

1422

1215

} else {

1423

1216

af = AF_INET;

1424

1217

}

1425

1426

if(quit_now){

1427

goto end;

1428

}

1429

1430

1218

ret = start_mandos_communication(address, port, if_index, af);

1431

1219

if(ret < 0){

1432

1220

exitcode = EXIT_FAILURE;

1435

1223

}

1436

1224

goto end;

1437

1225

}

1438

1439

if(quit_now){

1440

goto end;

1441

}

1442

1226

1443

1227

{

1444

1228

AvahiServerConfig config;

1445

1229

/* Do not publish any local Zeroconf records */

1466

1250

goto end;

1467

1251

}

1468

1252

1469

if(quit_now){

1470

goto end;

1471

}

1472

1473

1253

/* Create the Avahi service browser */

1474

1254

sb = avahi_s_service_browser_new(mc.server, if_index,

1475

1255

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1481

1261

goto end;

1482

1262

}

1483

1263

1484

if(quit_now){

1485

goto end;

1486

}

1487

1488

1264

/* Run the main loop */

1489

1265

1490

1266

if(debug){

1519

1295

gpgme_release(mc.ctx);

1520

1296

}

1521

1297

1522

/* Take down the network interface */

1523

if(take_down_interface){

1524

/* Re-raise priviliges */

1525

errno = 0;

1526

ret = seteuid(0);

1527

if(ret == -1){

1528

perror("seteuid");

1529

}

1530

if(geteuid() == 0){

1531

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

1532

if(ret == -1){

1533

perror("ioctl SIOCGIFFLAGS");

1534

} else if(network.ifr_flags & IFF_UP) {

1535

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

1536

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

1537

if(ret == -1){

1538

perror("ioctl SIOCSIFFLAGS");

1539

}

1540

}

1541

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

1542

if(ret == -1){

1543

perror("close");

1544

}

1545

/* Lower privileges permanently */

1546

errno = 0;

1547

ret = setuid(uid);

1548

if(ret == -1){

1549

perror("setuid");

1550

}

1551

}

1552

}

1553

1554

1298

/* Removes the temp directory used by GPGME */

1555

1299

if(tempdir_created){

1556

1300

DIR *d;

1595

1339

}

1596

1340

}

1597

1341

1598

if(quit_now){

1599

sigemptyset(&old_sigterm_action.sa_mask);

1600

old_sigterm_action.sa_handler = SIG_DFL;

1601

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

1602

if(ret == -1){

1603

perror("sigaction");

1604

}

1605

raise(signal_received);

1606

}

1607

1608

1342

return exitcode;

1609

1343

}