/mandos/trunk : revision 366

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

33

34

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

34

37

#define _FILE_OFFSET_BITS 64

38

#endif

35

39

36

40

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

37

41

67

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

68

72

*/

69

73

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

70

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

74

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

71

75

setgid() */

72

76

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

73

77

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

76

80

argp_parse(), ARGP_KEY_ARG,

77

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

78

82

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

79

sigaction(), SIGTERM, sigaction,

80

sig_atomic_t */

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

81

85

82

86

#ifdef __linux__

83

87

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

160

164

*/

161

165

static bool init_gpgme(const char *seckey,

162

166

const char *pubkey, const char *tempdir){

163

int ret;

164

167

gpgme_error_t rc;

165

168

gpgme_engine_info_t engine_info;

166

169

172

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

170

173

*/

171

174

bool import_key(const char *filename){

175

int ret;

172

176

int fd;

173

177

gpgme_data_t pgp_data;

174

178

245

249

return false;

246

250

}

247

251

248

return true;

252

return true;

249

253

}

250

254

251

255

/*

305

309

}

306

310

gpgme_recipient_t recipient;

307

311

recipient = result->recipients;

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

}

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;

318

320

}

319

321

}

320

322

}

512

514

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

513

515

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

514

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

515

520

/* Called when a Mandos server is found */

516

521

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

517

522

AvahiIfIndex if_index,

518

523

int af){

519

int ret, tcp_sd;

524

int ret, tcp_sd = -1;

520

525

ssize_t sret;

521

526

union {

522

527

struct sockaddr_in in;

526

531

char *decrypted_buffer;

527

532

size_t buffer_length = 0;

528

533

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

530

534

size_t written;

531

535

int retval = 0;

532

536

gnutls_session_t session;

533

537

int pf; /* Protocol family */

534

538

539

if(quit_now){

540

return -1;

541

}

542

535

543

switch(af){

536

544

case AF_INET6:

537

545

pf = PF_INET6;

557

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

558

566

if(tcp_sd < 0){

559

567

perror("socket");

560

return -1;

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

561

574

}

562

575

563

576

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

564

577

if(af == AF_INET6){

565

to.in6.sin6_family = (uint16_t)af;

578

to.in6.sin6_family = (sa_family_t)af;

566

579

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

567

580

} else { /* IPv4 */

568

581

to.in.sin_family = (sa_family_t)af;

570

583

}

571

584

if(ret < 0 ){

572

585

perror("inet_pton");

573

return -1;

586

retval = -1;

587

goto mandos_end;

574

588

}

575

589

if(ret == 0){

576

590

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

577

return -1;

591

retval = -1;

592

goto mandos_end;

578

593

}

579

594

if(af == AF_INET6){

580

595

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

587

602

if(if_index == AVAHI_IF_UNSPEC){

588

603

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

589

604

" without a network interface\n");

590

return -1;

605

retval = -1;

606

goto mandos_end;

591

607

}

592

608

/* Set the network interface number as scope */

593

609

to.in6.sin6_scope_id = (uint32_t)if_index;

598

614

-Wunreachable-code */

599

615

}

600

616

617

if(quit_now){

618

goto mandos_end;

619

}

620

601

621

if(debug){

602

622

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

603

623

char interface[IF_NAMESIZE];

630

650

}

631

651

}

632

652

653

if(quit_now){

654

goto mandos_end;

655

}

656

633

657

if(af == AF_INET6){

634

658

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

635

659

} else {

637

661

}

638

662

if(ret < 0){

639

663

perror("connect");

640

return -1;

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

641

670

}

642

671

643

672

const char *out = mandos_protocol_version;

662

691

break;

663

692

}

664

693

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

665

698

}

666

699

667

700

if(debug){

668

701

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

669

702

}

670

703

704

if(quit_now){

705

goto mandos_end;

706

}

707

671

708

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

672

709

673

do{

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

674

715

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

675

719

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

676

720

677

721

if(ret != GNUTLS_E_SUCCESS){

691

735

}

692

736

693

737

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

694

743

buffer_capacity = incbuffer(&buffer, buffer_length,

695

744

buffer_capacity);

696

745

if(buffer_capacity == 0){

699

748

goto mandos_end;

700

749

}

701

750

751

if(quit_now){

752

goto mandos_end;

753

}

754

702

755

sret = gnutls_record_recv(session, buffer+buffer_length,

703

756

BUFFER_SIZE);

704

757

if(sret == 0){

710

763

case GNUTLS_E_AGAIN:

711

764

break;

712

765

case GNUTLS_E_REHANDSHAKE:

713

do{

766

do {

714

767

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

715

772

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

716

773

if(ret < 0){

717

774

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

736

793

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

737

794

}

738

795

796

if(quit_now){

797

goto mandos_end;

798

}

799

739

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

740

801

802

if(quit_now){

803

goto mandos_end;

804

}

805

741

806

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

742

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

743

809

buffer_length,

744

810

&decrypted_buffer);

745

811

if(decrypted_buffer_size >= 0){

812

746

813

written = 0;

747

814

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

748

819

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

749

820

(size_t)decrypted_buffer_size - written,

750

821

stdout);

770

841

771

842

mandos_end:

772

843

free(buffer);

773

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

844

if(tcp_sd >= 0){

845

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

846

}

774

847

if(ret == -1){

775

848

perror("close");

776

849

}

777

850

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

778

854

return retval;

779

855

}

780

856

797

873

/* Called whenever a service has been resolved successfully or

798

874

timed out */

799

875

876

if(quit_now){

877

return;

878

}

879

800

880

switch(event){

801

881

default:

802

882

case AVAHI_RESOLVER_FAILURE:

839

919

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

840

920

is removed from the LAN */

841

921

922

if(quit_now){

923

return;

924

}

925

842

926

switch(event){

843

927

default:

844

928

case AVAHI_BROWSER_FAILURE:

873

957

}

874

958

}

875

959

876

sig_atomic_t quit_now = 0;

877

878

960

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

879

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

961

static void handle_sigterm(int sig){

880

962

if(quit_now){

881

963

return;

882

964

}

883

965

quit_now = 1;

966

signal_received = sig;

884

967

int old_errno = errno;

885

968

if(mc.simple_poll != NULL){

886

969

avahi_simple_poll_quit(mc.simple_poll);

897

980

int exitcode = EXIT_SUCCESS;

898

981

const char *interface = "eth0";

899

982

struct ifreq network;

900

int sd;

983

int sd = -1;

984

bool take_down_interface = false;

901

985

uid_t uid;

902

986

gid_t gid;

903

987

char *connect_to = NULL;

1046

1130

exitcode = EXIT_FAILURE;

1047

1131

goto end;

1048

1132

}

1049

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

1050

if(ret == -1){

1051

perror("sigaction");

1052

exitcode = EXIT_FAILURE;

1053

goto end;

1054

}

1133

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

1134

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

1135

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

1136

*/

1137

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

1138

if(ret == -1){

1139

perror("sigaction");

1140

return EXIT_FAILURE;

1141

}

1142

if(old_sigterm_action.sa_handler != SIG_IGN){

1143

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

1144

if(ret == -1){

1145

perror("sigaction");

1146

exitcode = EXIT_FAILURE;

1147

goto end;

1148

}

1149

}

1150

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

1151

if(ret == -1){

1152

perror("sigaction");

1153

return EXIT_FAILURE;

1154

}

1155

if(old_sigterm_action.sa_handler != SIG_IGN){

1156

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

1157

if(ret == -1){

1158

perror("sigaction");

1159

exitcode = EXIT_FAILURE;

1160

goto end;

1161

}

1162

}

1163

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

1170

if(ret == -1){

1171

perror("sigaction");

1172

exitcode = EXIT_FAILURE;

1173

goto end;

1174

}

1175

}

1055

1176

1056

1177

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

1057

1178

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

1179

if_index = (AvahiIfIndex) if_nametoindex(interface);

1180

if(if_index == 0){

1181

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

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

1186

if(quit_now){

1187

goto end;

1188

}

1189

1058

1190

#ifdef __linux__

1059

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1060

1192

messages to mess up the prompt */

1097

1229

}

1098

1230

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

1099

1231

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1100

1233

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

1101

1234

if(ret == -1){

1235

take_down_interface = false;

1102

1236

perror("ioctl SIOCSIFFLAGS");

1103

1237

exitcode = EXIT_FAILURE;

1104

1238

#ifdef __linux__

1126

1260

perror("nanosleep");

1127

1261

}

1128

1262

}

1129

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

1130

if(ret == -1){

1131

perror("close");

1263

if(not take_down_interface){

1264

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

1265

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

1266

if(ret == -1){

1267

perror("close");

1268

}

1132

1269

}

1133

1270

#ifdef __linux__

1134

1271

if(restore_loglevel){

1141

1278

#endif /* __linux__ */

1142

1279

}

1143

1280

1281

if(quit_now){

1282

goto end;

1283

}

1284

1144

1285

uid = getuid();

1145

1286

gid = getgid();

1146

1287

1288

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

1147

1289

errno = 0;

1148

setgid(gid);

1290

ret = setgid(gid);

1149

1291

if(ret == -1){

1150

1292

perror("setgid");

1151

1293

}

1152

1294

1153

ret = setuid(uid);

1154

if(ret == -1){

1155

perror("setuid");

1295

/* Drop user privileges */

1296

errno = 0;

1297

/* Will we need privileges later? */

1298

if(take_down_interface){

1299

/* Drop user privileges temporarily */

1300

ret = seteuid(uid);

1301

if(ret == -1){

1302

perror("seteuid");

1303

}

1304

} else {

1305

/* Drop user privileges permanently */

1306

ret = setuid(uid);

1307

if(ret == -1){

1308

perror("setuid");

1309

}

1310

}

1311

1312

if(quit_now){

1313

goto end;

1156

1314

}

1157

1315

1158

1316

ret = init_gnutls_global(pubkey, seckey);

1164

1322

gnutls_initialized = true;

1165

1323

}

1166

1324

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1167

1330

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1168

1332

perror("mkdtemp");

1169

1333

goto end;

1170

1334

}

1171

tempdir_created = true;

1335

1336

if(quit_now){

1337

goto end;

1338

}

1172

1339

1173

1340

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

1174

1341

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

1178

1345

gpgme_initialized = true;

1179

1346

}

1180

1347

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

}

1348

if(quit_now){

1349

goto end;

1188

1350

}

1189

1351

1190

1352

if(connect_to != NULL){

1196

1358

exitcode = EXIT_FAILURE;

1197

1359

goto end;

1198

1360

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1199

1366

uint16_t port;

1200

1367

errno = 0;

1201

1368

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

1205

1372

exitcode = EXIT_FAILURE;

1206

1373

goto end;

1207

1374

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1208

1380

port = (uint16_t)tmpmax;

1209

1381

*address = '\0';

1210

1382

address = connect_to;

1215

1387

} else {

1216

1388

af = AF_INET;

1217

1389

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1218

1395

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

1219

1396

if(ret < 0){

1220

1397

exitcode = EXIT_FAILURE;

1223

1400

}

1224

1401

goto end;

1225

1402

}

1226

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1227

1408

{

1228

1409

AvahiServerConfig config;

1229

1410

/* Do not publish any local Zeroconf records */

1250

1431

goto end;

1251

1432

}

1252

1433

1434

if(quit_now){

1435

goto end;

1436

}

1437

1253

1438

/* Create the Avahi service browser */

1254

1439

sb = avahi_s_service_browser_new(mc.server, if_index,

1255

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1261

1446

goto end;

1262

1447

}

1263

1448

1449

if(quit_now){

1450

goto end;

1451

}

1452

1264

1453

/* Run the main loop */

1265

1454

1266

1455

if(debug){

1295

1484

gpgme_release(mc.ctx);

1296

1485

}

1297

1486

1487

/* Take down the network interface */

1488

if(take_down_interface){

1489

/* Re-raise priviliges */

1490

errno = 0;

1491

ret = seteuid(0);

1492

if(ret == -1){

1493

perror("seteuid");

1494

}

1495

if(geteuid() == 0){

1496

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

1497

if(ret == -1){

1498

perror("ioctl SIOCGIFFLAGS");

1499

} else if(network.ifr_flags & IFF_UP) {

1500

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

1501

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

1502

if(ret == -1){

1503

perror("ioctl SIOCSIFFLAGS");

1504

}

1505

}

1506

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

1507

if(ret == -1){

1508

perror("close");

1509

}

1510

/* Lower privileges, permanently this time */

1511

errno = 0;

1512

ret = setuid(uid);

1513

if(ret == -1){

1514

perror("setuid");

1515

}

1516

}

1517

}

1518

1298

1519

/* Removes the temp directory used by GPGME */

1299

1520

if(tempdir_created){

1300

1521

DIR *d;

1339

1560

}

1340

1561

}

1341

1562

1563

if(quit_now){

1564

sigemptyset(&old_sigterm_action.sa_mask);

1565

old_sigterm_action.sa_handler = SIG_DFL;

1566

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

1567

if(ret == -1){

1568

perror("sigaction");

1569

}

1570

raise(signal_received);

1571

}

1572

1342

1573

return exitcode;

1343

1574

}