/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

}

514

512

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

515

513

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

516

514

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

515

/* Called when a Mandos server is found */

521

516

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

522

517

AvahiIfIndex if_index,

523

518

int af){

524

int ret, tcp_sd = -1;

519

int ret, tcp_sd;

525

520

ssize_t sret;

526

521

union {

527

522

struct sockaddr_in in;

531

526

char *decrypted_buffer;

532

527

size_t buffer_length = 0;

533

528

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

534

530

size_t written;

535

531

int retval = 0;

536

532

gnutls_session_t session;

537

533

int pf; /* Protocol family */

538

534

539

if(quit_now){

540

return -1;

541

}

542

543

535

switch(af){

544

536

case AF_INET6:

545

537

pf = PF_INET6;

565

557

tcp_sd = socket(pf, SOCK_STREAM, 0);

566

558

if(tcp_sd < 0){

567

559

perror("socket");

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

560

return -1;

574

561

}

575

562

576

563

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

577

564

if(af == AF_INET6){

578

to.in6.sin6_family = (sa_family_t)af;

565

to.in6.sin6_family = (uint16_t)af;

579

566

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

580

567

} else { /* IPv4 */

581

568

to.in.sin_family = (sa_family_t)af;

583

570

}

584

571

if(ret < 0 ){

585

572

perror("inet_pton");

586

retval = -1;

587

goto mandos_end;

573

return -1;

588

574

}

589

575

if(ret == 0){

590

576

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

591

retval = -1;

592

goto mandos_end;

577

return -1;

593

578

}

594

579

if(af == AF_INET6){

595

580

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

602

587

if(if_index == AVAHI_IF_UNSPEC){

603

588

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

604

589

" without a network interface\n");

605

retval = -1;

606

goto mandos_end;

590

return -1;

607

591

}

608

592

/* Set the network interface number as scope */

609

593

to.in6.sin6_scope_id = (uint32_t)if_index;

614

598

-Wunreachable-code */

615

599

}

616

600

617

if(quit_now){

618

goto mandos_end;

619

}

620

621

601

if(debug){

622

602

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

623

603

char interface[IF_NAMESIZE];

650

630

}

651

631

}

652

632

653

if(quit_now){

654

goto mandos_end;

655

}

656

657

633

if(af == AF_INET6){

658

634

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

659

635

} else {

661

637

}

662

638

if(ret < 0){

663

639

perror("connect");

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

640

return -1;

670

641

}

671

642

672

643

const char *out = mandos_protocol_version;

691

662

break;

692

663

}

693

664

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

698

665

}

699

666

700

667

if(debug){

701

668

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

702

669

}

703

670

704

if(quit_now){

705

goto mandos_end;

706

}

707

708

671

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

709

672

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

673

do{

715

674

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

719

675

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

720

676

721

677

if(ret != GNUTLS_E_SUCCESS){

735

691

}

736

692

737

693

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

743

694

buffer_capacity = incbuffer(&buffer, buffer_length,

744

695

buffer_capacity);

745

696

if(buffer_capacity == 0){

748

699

goto mandos_end;

749

700

}

750

701

751

if(quit_now){

752

goto mandos_end;

753

}

754

755

702

sret = gnutls_record_recv(session, buffer+buffer_length,

756

703

BUFFER_SIZE);

757

704

if(sret == 0){

763

710

case GNUTLS_E_AGAIN:

764

711

break;

765

712

case GNUTLS_E_REHANDSHAKE:

766

do {

713

do{

767

714

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

772

715

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

773

716

if(ret < 0){

774

717

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

793

736

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

794

737

}

795

738

796

if(quit_now){

797

goto mandos_end;

798

}

799

800

739

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

740

802

if(quit_now){

803

goto mandos_end;

804

}

805

806

741

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

808

742

decrypted_buffer_size = pgp_packet_decrypt(buffer,

809

743

buffer_length,

810

744

&decrypted_buffer);

811

745

if(decrypted_buffer_size >= 0){

812

813

746

written = 0;

814

747

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

819

748

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

820

749

(size_t)decrypted_buffer_size - written,

821

750

stdout);

841

770

842

771

mandos_end:

843

772

free(buffer);

844

if(tcp_sd >= 0){

845

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

846

}

773

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

847

774

if(ret == -1){

848

775

perror("close");

849

776

}

850

777

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

854

778

return retval;

855

779

}

856

780

873

797

/* Called whenever a service has been resolved successfully or

874

798

timed out */

875

799

876

if(quit_now){

877

return;

878

}

879

880

800

switch(event){

881

801

default:

882

802

case AVAHI_RESOLVER_FAILURE:

919

839

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

920

840

is removed from the LAN */

921

841

922

if(quit_now){

923

return;

924

}

925

926

842

switch(event){

927

843

default:

928

844

case AVAHI_BROWSER_FAILURE:

957

873

}

958

874

}

959

875

876

sig_atomic_t quit_now = 0;

877

960

878

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

961

static void handle_sigterm(int sig){

879

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

962

880

if(quit_now){

963

881

return;

964

882

}

965

883

quit_now = 1;

966

signal_received = sig;

967

884

int old_errno = errno;

968

885

if(mc.simple_poll != NULL){

969

886

avahi_simple_poll_quit(mc.simple_poll);

980

897

int exitcode = EXIT_SUCCESS;

981

898

const char *interface = "eth0";

982

899

struct ifreq network;

983

int sd = -1;

984

bool take_down_interface = false;

900

int sd;

985

901

uid_t uid;

986

902

gid_t gid;

987

903

char *connect_to = NULL;

1130

1046

exitcode = EXIT_FAILURE;

1131

1047

goto end;

1132

1048

}

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

}

1049

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

1050

if(ret == -1){

1051

perror("sigaction");

1052

exitcode = EXIT_FAILURE;

1053

goto end;

1054

}

1176

1055

1177

1056

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

1178

1057

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

1190

1058

#ifdef __linux__

1191

1059

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1192

1060

messages to mess up the prompt */

1229

1097

}

1230

1098

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

1231

1099

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1233

1100

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

1234

1101

if(ret == -1){

1235

take_down_interface = false;

1236

1102

perror("ioctl SIOCSIFFLAGS");

1237

1103

exitcode = EXIT_FAILURE;

1238

1104

#ifdef __linux__

1260

1126

perror("nanosleep");

1261

1127

}

1262

1128

}

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

}

1129

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

1130

if(ret == -1){

1131

perror("close");

1269

1132

}

1270

1133

#ifdef __linux__

1271

1134

if(restore_loglevel){

1278

1141

#endif /* __linux__ */

1279

1142

}

1280

1143

1281

if(quit_now){

1282

goto end;

1283

}

1284

1285

1144

uid = getuid();

1286

1145

gid = getgid();

1287

1146

1288

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

1289

1147

errno = 0;

1290

ret = setgid(gid);

1148

setgid(gid);

1291

1149

if(ret == -1){

1292

1150

perror("setgid");

1293

1151

}

1294

1152

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;

1153

ret = setuid(uid);

1154

if(ret == -1){

1155

perror("setuid");

1314

1156

}

1315

1157

1316

1158

ret = init_gnutls_global(pubkey, seckey);

1322

1164

gnutls_initialized = true;

1323

1165

}

1324

1166

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1330

1167

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1332

1168

perror("mkdtemp");

1333

1169

goto end;

1334

1170

}

1335

1336

if(quit_now){

1337

goto end;

1338

}

1171

tempdir_created = true;

1339

1172

1340

1173

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

1341

1174

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

1345

1178

gpgme_initialized = true;

1346

1179

}

1347

1180

1348

if(quit_now){

1349

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

}

1350

1188

}

1351

1189

1352

1190

if(connect_to != NULL){

1358

1196

exitcode = EXIT_FAILURE;

1359

1197

goto end;

1360

1198

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1366

1199

uint16_t port;

1367

1200

errno = 0;

1368

1201

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

1372

1205

exitcode = EXIT_FAILURE;

1373

1206

goto end;

1374

1207

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1380

1208

port = (uint16_t)tmpmax;

1381

1209

*address = '\0';

1382

1210

address = connect_to;

1387

1215

} else {

1388

1216

af = AF_INET;

1389

1217

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1395

1218

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

1396

1219

if(ret < 0){

1397

1220

exitcode = EXIT_FAILURE;

1400

1223

}

1401

1224

goto end;

1402

1225

}

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1226

1408

1227

{

1409

1228

AvahiServerConfig config;

1410

1229

/* Do not publish any local Zeroconf records */

1431

1250

goto end;

1432

1251

}

1433

1252

1434

if(quit_now){

1435

goto end;

1436

}

1437

1438

1253

/* Create the Avahi service browser */

1439

1254

sb = avahi_s_service_browser_new(mc.server, if_index,

1440

1255

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1446

1261

goto end;

1447

1262

}

1448

1263

1449

if(quit_now){

1450

goto end;

1451

}

1452

1453

1264

/* Run the main loop */

1454

1265

1455

1266

if(debug){

1484

1295

gpgme_release(mc.ctx);

1485

1296

}

1486

1297

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

1519

1298

/* Removes the temp directory used by GPGME */

1520

1299

if(tempdir_created){

1521

1300

DIR *d;

1560

1339

}

1561

1340

}

1562

1341

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

1573

1342

return exitcode;

1574

1343

}