/mandos/trunk : revision 365

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

73

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

74

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

74

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

75

setgid() */

76

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

77

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

80

argp_parse(), ARGP_KEY_ARG,

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sigaction,

84

sig_atomic_t */

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

86

#ifdef __linux__

87

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

164

*/

165

static bool init_gpgme(const char *seckey,

166

const char *pubkey, const char *tempdir){

167

int ret;

168

167

gpgme_error_t rc;

169

168

gpgme_engine_info_t engine_info;

170

169

173

172

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

174

173

*/

175

174

bool import_key(const char *filename){

175

int ret;

176

int fd;

177

gpgme_data_t pgp_data;

178

249

return false;

250

}

251

252

return true;

252

return true;

253

}

254

255

/*

309

}

310

gpgme_recipient_t recipient;

311

recipient = result->recipients;

312

if(recipient){

313

while(recipient != NULL){

314

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

315

gpgme_pubkey_algo_name(recipient->pubkey_algo));

316

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

317

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

318

recipient->status == GPG_ERR_NO_SECKEY

319

? "No" : "Yes");

320

recipient = recipient->next;

321

}

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;

322

320

}

323

321

}

324

322

}

516

514

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

517

515

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

518

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

/* Called when a Mandos server is found */

520

521

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

521

522

AvahiIfIndex if_index,

522

523

int af){

523

int ret, tcp_sd;

524

int ret, tcp_sd = -1;

524

525

ssize_t sret;

525

526

union {

526

527

struct sockaddr_in in;

530

531

char *decrypted_buffer;

531

532

size_t buffer_length = 0;

532

533

size_t buffer_capacity = 0;

533

ssize_t decrypted_buffer_size;

534

size_t written;

535

int retval = 0;

536

gnutls_session_t session;

537

int pf; /* Protocol family */

538

539

if(quit_now){

540

return -1;

541

}

542

539

543

switch(af){

540

544

case AF_INET6:

541

545

pf = PF_INET6;

561

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

562

566

if(tcp_sd < 0){

563

567

perror("socket");

564

return -1;

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

565

574

}

566

575

567

576

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

574

583

}

575

584

if(ret < 0 ){

576

585

perror("inet_pton");

577

return -1;

586

retval = -1;

587

goto mandos_end;

578

588

}

579

589

if(ret == 0){

580

590

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

581

return -1;

591

retval = -1;

592

goto mandos_end;

582

593

}

583

594

if(af == AF_INET6){

584

595

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

591

602

if(if_index == AVAHI_IF_UNSPEC){

592

603

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

593

604

" without a network interface\n");

594

return -1;

605

retval = -1;

606

goto mandos_end;

595

607

}

596

608

/* Set the network interface number as scope */

597

609

to.in6.sin6_scope_id = (uint32_t)if_index;

602

614

-Wunreachable-code */

603

615

}

604

616

617

if(quit_now){

618

goto mandos_end;

619

}

620

605

621

if(debug){

606

622

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

607

623

char interface[IF_NAMESIZE];

634

650

}

635

651

}

636

652

653

if(quit_now){

654

goto mandos_end;

655

}

656

637

657

if(af == AF_INET6){

638

658

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

639

659

} else {

641

661

}

642

662

if(ret < 0){

643

663

perror("connect");

644

return -1;

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

645

670

}

646

671

647

672

const char *out = mandos_protocol_version;

666

691

break;

667

692

}

668

693

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

669

698

}

670

699

671

700

if(debug){

672

701

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

673

702

}

674

703

704

if(quit_now){

705

goto mandos_end;

706

}

707

675

708

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

676

709

677

do{

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

678

715

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

679

719

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

680

720

681

721

if(ret != GNUTLS_E_SUCCESS){

695

735

}

696

736

697

737

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

698

743

buffer_capacity = incbuffer(&buffer, buffer_length,

699

744

buffer_capacity);

700

745

if(buffer_capacity == 0){

703

748

goto mandos_end;

704

749

}

705

750

751

if(quit_now){

752

goto mandos_end;

753

}

754

706

755

sret = gnutls_record_recv(session, buffer+buffer_length,

707

756

BUFFER_SIZE);

708

757

if(sret == 0){

714

763

case GNUTLS_E_AGAIN:

715

764

break;

716

765

case GNUTLS_E_REHANDSHAKE:

717

do{

766

do {

718

767

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

719

772

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

720

773

if(ret < 0){

721

774

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

740

793

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

741

794

}

742

795

796

if(quit_now){

797

goto mandos_end;

798

}

799

743

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

744

801

802

if(quit_now){

803

goto mandos_end;

804

}

805

745

806

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

746

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

747

809

buffer_length,

748

810

&decrypted_buffer);

749

811

if(decrypted_buffer_size >= 0){

812

750

813

written = 0;

751

814

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

752

819

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

753

820

(size_t)decrypted_buffer_size - written,

754

821

stdout);

774

841

775

842

mandos_end:

776

843

free(buffer);

777

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

844

if(tcp_sd >= 0){

845

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

846

}

778

847

if(ret == -1){

779

848

perror("close");

780

849

}

781

850

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

782

854

return retval;

783

855

}

784

856

801

873

/* Called whenever a service has been resolved successfully or

802

874

timed out */

803

875

876

if(quit_now){

877

return;

878

}

879

804

880

switch(event){

805

881

default:

806

882

case AVAHI_RESOLVER_FAILURE:

843

919

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

844

920

is removed from the LAN */

845

921

922

if(quit_now){

923

return;

924

}

925

846

926

switch(event){

847

927

default:

848

928

case AVAHI_BROWSER_FAILURE:

877

957

}

878

958

}

879

959

880

sig_atomic_t quit_now = 0;

881

882

960

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

883

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

961

static void handle_sigterm(int sig){

884

962

if(quit_now){

885

963

return;

886

964

}

887

965

quit_now = 1;

966

signal_received = sig;

888

967

int old_errno = errno;

889

968

if(mc.simple_poll != NULL){

890

969

avahi_simple_poll_quit(mc.simple_poll);

901

980

int exitcode = EXIT_SUCCESS;

902

981

const char *interface = "eth0";

903

982

struct ifreq network;

904

int sd;

983

int sd = -1;

984

bool take_down_interface = false;

905

985

uid_t uid;

906

986

gid_t gid;

907

987

char *connect_to = NULL;

1050

1130

exitcode = EXIT_FAILURE;

1051

1131

goto end;

1052

1132

}

1053

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

1054

if(ret == -1){

1055

perror("sigaction");

1056

exitcode = EXIT_FAILURE;

1057

goto end;

1058

}

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

}

1059

1176

1060

1177

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

1061

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

1062

1190

#ifdef __linux__

1063

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1064

1192

messages to mess up the prompt */

1101

1229

}

1102

1230

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

1103

1231

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1104

1233

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

1105

1234

if(ret == -1){

1235

take_down_interface = false;

1106

1236

perror("ioctl SIOCSIFFLAGS");

1107

1237

exitcode = EXIT_FAILURE;

1108

1238

#ifdef __linux__

1130

1260

perror("nanosleep");

1131

1261

}

1132

1262

}

1133

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

1134

if(ret == -1){

1135

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

}

1136

1269

}

1137

1270

#ifdef __linux__

1138

1271

if(restore_loglevel){

1145

1278

#endif /* __linux__ */

1146

1279

}

1147

1280

1281

if(quit_now){

1282

goto end;

1283

}

1284

1148

1285

uid = getuid();

1149

1286

gid = getgid();

1150

1287

1288

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

1151

1289

errno = 0;

1152

setgid(gid);

1290

ret = setgid(gid);

1153

1291

if(ret == -1){

1154

1292

perror("setgid");

1155

1293

}

1156

1294

1157

ret = setuid(uid);

1158

if(ret == -1){

1159

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;

1160

1314

}

1161

1315

1162

1316

ret = init_gnutls_global(pubkey, seckey);

1168

1322

gnutls_initialized = true;

1169

1323

}

1170

1324

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1171

1330

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1172

1332

perror("mkdtemp");

1173

1333

goto end;

1174

1334

}

1175

tempdir_created = true;

1335

1336

if(quit_now){

1337

goto end;

1338

}

1176

1339

1177

1340

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

1178

1341

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

1182

1345

gpgme_initialized = true;

1183

1346

}

1184

1347

1185

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

1186

if_index = (AvahiIfIndex) if_nametoindex(interface);

1187

if(if_index == 0){

1188

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

1189

exitcode = EXIT_FAILURE;

1190

goto end;

1191

}

1348

if(quit_now){

1349

goto end;

1192

1350

}

1193

1351

1194

1352

if(connect_to != NULL){

1200

1358

exitcode = EXIT_FAILURE;

1201

1359

goto end;

1202

1360

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1203

1366

uint16_t port;

1204

1367

errno = 0;

1205

1368

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

1209

1372

exitcode = EXIT_FAILURE;

1210

1373

goto end;

1211

1374

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1212

1380

port = (uint16_t)tmpmax;

1213

1381

*address = '\0';

1214

1382

address = connect_to;

1219

1387

} else {

1220

1388

af = AF_INET;

1221

1389

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1222

1395

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

1223

1396

if(ret < 0){

1224

1397

exitcode = EXIT_FAILURE;

1227

1400

}

1228

1401

goto end;

1229

1402

}

1230

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1231

1408

{

1232

1409

AvahiServerConfig config;

1233

1410

/* Do not publish any local Zeroconf records */

1254

1431

goto end;

1255

1432

}

1256

1433

1434

if(quit_now){

1435

goto end;

1436

}

1437

1257

1438

/* Create the Avahi service browser */

1258

1439

sb = avahi_s_service_browser_new(mc.server, if_index,

1259

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1265

1446

goto end;

1266

1447

}

1267

1448

1449

if(quit_now){

1450

goto end;

1451

}

1452

1268

1453

/* Run the main loop */

1269

1454

1270

1455

if(debug){

1299

1484

gpgme_release(mc.ctx);

1300

1485

}

1301

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

1302

1519

/* Removes the temp directory used by GPGME */

1303

1520

if(tempdir_created){

1304

1521

DIR *d;

1343

1560

}

1344

1561

}

1345

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

1346

1573

return exitcode;

1347

1574

}