/mandos/trunk : revision 371

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() */

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

145

148

/*

146

149

* Make additional room in "buffer" for at least BUFFER_SIZE more

147

150

* bytes. "buffer_capacity" is how much is currently allocated,

164

167

*/

165

168

static bool init_gpgme(const char *seckey,

166

169

const char *pubkey, const char *tempdir){

167

int ret;

168

170

gpgme_error_t rc;

169

171

gpgme_engine_info_t engine_info;

170

172

173

175

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

174

176

*/

175

177

bool import_key(const char *filename){

178

int ret;

176

179

int fd;

177

180

gpgme_data_t pgp_data;

178

181

249

252

return false;

250

253

}

251

254

252

return true;

255

return true;

253

256

}

254

257

255

258

/*

309

312

}

310

313

gpgme_recipient_t recipient;

311

314

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

}

315

while(recipient != NULL){

316

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

317

gpgme_pubkey_algo_name(recipient->pubkey_algo));

318

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

319

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

320

recipient->status == GPG_ERR_NO_SECKEY

321

? "No" : "Yes");

322

recipient = recipient->next;

322

323

}

323

324

}

324

325

}

476

477

static int init_gnutls_session(gnutls_session_t *session){

477

478

int ret;

478

479

/* GnuTLS session creation */

479

ret = gnutls_init(session, GNUTLS_SERVER);

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);

480

486

if(ret != GNUTLS_E_SUCCESS){

481

487

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

482

488

safer_gnutls_strerror(ret));

484

490

485

491

{

486

492

const char *err;

487

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

488

500

if(ret != GNUTLS_E_SUCCESS){

489

501

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

490

502

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

494

506

}

495

507

}

496

508

497

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

498

mc.cred);

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);

499

517

if(ret != GNUTLS_E_SUCCESS){

500

518

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

501

519

safer_gnutls_strerror(ret));

504

522

}

505

523

506

524

/* ignore client certificate if any. */

507

gnutls_certificate_server_set_request(*session,

508

GNUTLS_CERT_IGNORE);

525

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

509

526

510

527

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

511

528

520

537

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

521

538

AvahiIfIndex if_index,

522

539

int af){

523

int ret, tcp_sd;

540

int ret, tcp_sd = -1;

524

541

ssize_t sret;

525

542

union {

526

543

struct sockaddr_in in;

530

547

char *decrypted_buffer;

531

548

size_t buffer_length = 0;

532

549

size_t buffer_capacity = 0;

533

ssize_t decrypted_buffer_size;

534

550

size_t written;

535

551

int retval = 0;

536

552

gnutls_session_t session;

537

553

int pf; /* Protocol family */

538

554

555

if(quit_now){

556

return -1;

557

}

558

539

559

switch(af){

540

560

case AF_INET6:

541

561

pf = PF_INET6;

561

581

tcp_sd = socket(pf, SOCK_STREAM, 0);

562

582

if(tcp_sd < 0){

563

583

perror("socket");

564

return -1;

584

retval = -1;

585

goto mandos_end;

586

}

587

588

if(quit_now){

589

retval = -1;

590

goto mandos_end;

565

591

}

566

592

567

593

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

568

594

if(af == AF_INET6){

569

to.in6.sin6_family = (uint16_t)af;

595

to.in6.sin6_family = (sa_family_t)af;

570

596

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

571

597

} else { /* IPv4 */

572

598

to.in.sin_family = (sa_family_t)af;

574

600

}

575

601

if(ret < 0 ){

576

602

perror("inet_pton");

577

return -1;

603

retval = -1;

604

goto mandos_end;

578

605

}

579

606

if(ret == 0){

580

607

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

581

return -1;

608

retval = -1;

609

goto mandos_end;

582

610

}

583

611

if(af == AF_INET6){

584

612

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

591

619

if(if_index == AVAHI_IF_UNSPEC){

592

620

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

593

621

" without a network interface\n");

594

return -1;

622

retval = -1;

623

goto mandos_end;

595

624

}

596

625

/* Set the network interface number as scope */

597

626

to.in6.sin6_scope_id = (uint32_t)if_index;

602

631

-Wunreachable-code */

603

632

}

604

633

634

if(quit_now){

635

retval = -1;

636

goto mandos_end;

637

}

638

605

639

if(debug){

606

640

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

607

641

char interface[IF_NAMESIZE];

634

668

}

635

669

}

636

670

671

if(quit_now){

672

retval = -1;

673

goto mandos_end;

674

}

675

637

676

if(af == AF_INET6){

638

677

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

639

678

} else {

641

680

}

642

681

if(ret < 0){

643

682

perror("connect");

644

return -1;

683

retval = -1;

684

goto mandos_end;

685

}

686

687

if(quit_now){

688

retval = -1;

689

goto mandos_end;

645

690

}

646

691

647

692

const char *out = mandos_protocol_version;

666

711

break;

667

712

}

668

713

}

714

715

if(quit_now){

716

retval = -1;

717

goto mandos_end;

718

}

669

719

}

670

720

671

721

if(debug){

672

722

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

673

723

}

674

724

725

if(quit_now){

726

retval = -1;

727

goto mandos_end;

728

}

729

675

730

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

676

731

677

do{

732

if(quit_now){

733

retval = -1;

734

goto mandos_end;

735

}

736

737

do {

678

738

ret = gnutls_handshake(session);

739

if(quit_now){

740

retval = -1;

741

goto mandos_end;

742

}

679

743

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

680

744

681

745

if(ret != GNUTLS_E_SUCCESS){

695

759

}

696

760

697

761

while(true){

762

763

if(quit_now){

764

retval = -1;

765

goto mandos_end;

766

}

767

698

768

buffer_capacity = incbuffer(&buffer, buffer_length,

699

769

buffer_capacity);

700

770

if(buffer_capacity == 0){

703

773

goto mandos_end;

704

774

}

705

775

776

if(quit_now){

777

retval = -1;

778

goto mandos_end;

779

}

780

706

781

sret = gnutls_record_recv(session, buffer+buffer_length,

707

782

BUFFER_SIZE);

708

783

if(sret == 0){

714

789

case GNUTLS_E_AGAIN:

715

790

break;

716

791

case GNUTLS_E_REHANDSHAKE:

717

do{

792

do {

718

793

ret = gnutls_handshake(session);

794

795

if(quit_now){

796

retval = -1;

797

goto mandos_end;

798

}

719

799

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

720

800

if(ret < 0){

721

801

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

740

820

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

741

821

}

742

822

743

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

if(quit_now){

824

retval = -1;

825

goto mandos_end;

826

}

827

828

do {

829

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

830

if(quit_now){

831

retval = -1;

832

goto mandos_end;

833

}

834

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

744

835

745

836

if(buffer_length > 0){

837

ssize_t decrypted_buffer_size;

746

838

decrypted_buffer_size = pgp_packet_decrypt(buffer,

747

839

buffer_length,

748

840

&decrypted_buffer);

749

841

if(decrypted_buffer_size >= 0){

842

750

843

written = 0;

751

844

while(written < (size_t) decrypted_buffer_size){

845

if(quit_now){

846

retval = -1;

847

goto mandos_end;

848

}

849

752

850

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

753

851

(size_t)decrypted_buffer_size - written,

754

852

stdout);

774

872

775

873

mandos_end:

776

874

free(buffer);

777

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

875

if(tcp_sd >= 0){

876

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

877

}

778

878

if(ret == -1){

779

879

perror("close");

780

880

}

781

881

gnutls_deinit(session);

882

if(quit_now){

883

retval = -1;

884

}

782

885

return retval;

783

886

}

784

887

801

904

/* Called whenever a service has been resolved successfully or

802

905

timed out */

803

906

907

if(quit_now){

908

return;

909

}

910

804

911

switch(event){

805

912

default:

806

913

case AVAHI_RESOLVER_FAILURE:

843

950

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

844

951

is removed from the LAN */

845

952

953

if(quit_now){

954

return;

955

}

956

846

957

switch(event){

847

958

default:

848

959

case AVAHI_BROWSER_FAILURE:

877

988

}

878

989

}

879

990

880

sig_atomic_t quit_now = 0;

881

882

991

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

883

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

992

static void handle_sigterm(int sig){

884

993

if(quit_now){

885

994

return;

886

995

}

887

996

quit_now = 1;

997

signal_received = sig;

888

998

int old_errno = errno;

889

999

if(mc.simple_poll != NULL){

890

1000

avahi_simple_poll_quit(mc.simple_poll);

901

1011

int exitcode = EXIT_SUCCESS;

902

1012

const char *interface = "eth0";

903

1013

struct ifreq network;

904

int sd;

1014

int sd = -1;

1015

bool take_down_interface = false;

905

1016

uid_t uid;

906

1017

gid_t gid;

907

1018

char *connect_to = NULL;

915

1026

bool gpgme_initialized = false;

916

1027

float delay = 2.5f;

917

1028

918

struct sigaction old_sigterm_action;

1029

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

919

1030

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

920

1031

1032

uid = getuid();

1033

gid = getgid();

1034

1035

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

1036

errno = 0;

1037

ret = setgid(gid);

1038

if(ret == -1){

1039

perror("setgid");

1040

}

1041

1042

/* Lower user privileges (temporarily) */

1043

errno = 0;

1044

ret = seteuid(uid);

1045

if(ret == -1){

1046

perror("seteuid");

1047

}

1048

1049

if(quit_now){

1050

goto end;

1051

}

1052

921

1053

{

922

1054

struct argp_option options[] = {

923

1055

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

1050

1182

exitcode = EXIT_FAILURE;

1051

1183

goto end;

1052

1184

}

1053

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

1054

if(ret == -1){

1055

perror("sigaction");

1056

exitcode = EXIT_FAILURE;

1057

goto end;

1058

}

1185

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

1186

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

1187

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

1188

*/

1189

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

1196

if(ret == -1){

1197

perror("sigaction");

1198

exitcode = EXIT_FAILURE;

1199

goto end;

1200

}

1201

}

1202

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

1203

if(ret == -1){

1204

perror("sigaction");

1205

return EXIT_FAILURE;

1206

}

1207

if(old_sigterm_action.sa_handler != SIG_IGN){

1208

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

1209

if(ret == -1){

1210

perror("sigaction");

1211

exitcode = EXIT_FAILURE;

1212

goto end;

1213

}

1214

}

1215

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

1216

if(ret == -1){

1217

perror("sigaction");

1218

return EXIT_FAILURE;

1219

}

1220

if(old_sigterm_action.sa_handler != SIG_IGN){

1221

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

1222

if(ret == -1){

1223

perror("sigaction");

1224

exitcode = EXIT_FAILURE;

1225

goto end;

1226

}

1227

}

1059

1228

1060

1229

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

1061

1230

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

1231

if_index = (AvahiIfIndex) if_nametoindex(interface);

1232

if(if_index == 0){

1233

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

1234

exitcode = EXIT_FAILURE;

1235

goto end;

1236

}

1237

1238

if(quit_now){

1239

goto end;

1240

}

1241

1242

/* Re-raise priviliges */

1243

errno = 0;

1244

ret = seteuid(0);

1245

if(ret == -1){

1246

perror("seteuid");

1247

}

1248

1062

1249

#ifdef __linux__

1063

1250

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1064

1251

messages to mess up the prompt */

1082

1269

}

1083

1270

}

1084

1271

#endif /* __linux__ */

1272

/* Lower privileges */

1273

errno = 0;

1274

ret = seteuid(uid);

1275

if(ret == -1){

1276

perror("seteuid");

1277

}

1085

1278

goto end;

1086

1279

}

1087

1280

strcpy(network.ifr_name, interface);

1097

1290

}

1098

1291

#endif /* __linux__ */

1099

1292

exitcode = EXIT_FAILURE;

1293

/* Lower privileges */

1294

errno = 0;

1295

ret = seteuid(uid);

1296

if(ret == -1){

1297

perror("seteuid");

1298

}

1100

1299

goto end;

1101

1300

}

1102

1301

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

1103

1302

network.ifr_flags |= IFF_UP;

1303

take_down_interface = true;

1104

1304

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

1105

1305

if(ret == -1){

1306

take_down_interface = false;

1106

1307

perror("ioctl SIOCSIFFLAGS");

1107

1308

exitcode = EXIT_FAILURE;

1108

1309

#ifdef __linux__

1113

1314

}

1114

1315

}

1115

1316

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1116

1323

goto end;

1117

1324

}

1118

1325

}

1130

1337

perror("nanosleep");

1131

1338

}

1132

1339

}

1133

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

1134

if(ret == -1){

1135

perror("close");

1340

if(not take_down_interface){

1341

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

1342

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

1343

if(ret == -1){

1344

perror("close");

1345

}

1136

1346

}

1137

1347

#ifdef __linux__

1138

1348

if(restore_loglevel){

1143

1353

}

1144

1354

}

1145

1355

#endif /* __linux__ */

1146

}

1147

1148

uid = getuid();

1149

gid = getgid();

1150

1151

errno = 0;

1152

setgid(gid);

1153

if(ret == -1){

1154

perror("setgid");

1155

}

1156

1157

ret = setuid(uid);

1158

if(ret == -1){

1159

perror("setuid");

1356

/* Lower privileges */

1357

errno = 0;

1358

if(take_down_interface){

1359

/* Lower privileges */

1360

ret = seteuid(uid);

1361

if(ret == -1){

1362

perror("seteuid");

1363

}

1364

} else {

1365

/* Lower privileges permanently */

1366

ret = setuid(uid);

1367

if(ret == -1){

1368

perror("setuid");

1369

}

1370

}

1371

}

1372

1373

if(quit_now){

1374

goto end;

1160

1375

}

1161

1376

1162

1377

ret = init_gnutls_global(pubkey, seckey);

1168

1383

gnutls_initialized = true;

1169

1384

}

1170

1385

1386

if(quit_now){

1387

goto end;

1388

}

1389

1390

tempdir_created = true;

1171

1391

if(mkdtemp(tempdir) == NULL){

1392

tempdir_created = false;

1172

1393

perror("mkdtemp");

1173

1394

goto end;

1174

1395

}

1175

tempdir_created = true;

1396

1397

if(quit_now){

1398

goto end;

1399

}

1176

1400

1177

1401

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

1178

1402

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

1182

1406

gpgme_initialized = true;

1183

1407

}

1184

1408

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

}

1409

if(quit_now){

1410

goto end;

1192

1411

}

1193

1412

1194

1413

if(connect_to != NULL){

1200

1419

exitcode = EXIT_FAILURE;

1201

1420

goto end;

1202

1421

}

1422

1423

if(quit_now){

1424

goto end;

1425

}

1426

1203

1427

uint16_t port;

1204

1428

errno = 0;

1205

1429

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

1209

1433

exitcode = EXIT_FAILURE;

1210

1434

goto end;

1211

1435

}

1436

1437

if(quit_now){

1438

goto end;

1439

}

1440

1212

1441

port = (uint16_t)tmpmax;

1213

1442

*address = '\0';

1214

1443

address = connect_to;

1219

1448

} else {

1220

1449

af = AF_INET;

1221

1450

}

1451

1452

if(quit_now){

1453

goto end;

1454

}

1455

1222

1456

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

1223

1457

if(ret < 0){

1224

1458

exitcode = EXIT_FAILURE;

1227

1461

}

1228

1462

goto end;

1229

1463

}

1230

1464

1465

if(quit_now){

1466

goto end;

1467

}

1468

1231

1469

{

1232

1470

AvahiServerConfig config;

1233

1471

/* Do not publish any local Zeroconf records */

1254

1492

goto end;

1255

1493

}

1256

1494

1495

if(quit_now){

1496

goto end;

1497

}

1498

1257

1499

/* Create the Avahi service browser */

1258

1500

sb = avahi_s_service_browser_new(mc.server, if_index,

1259

1501

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1265

1507

goto end;

1266

1508

}

1267

1509

1510

if(quit_now){

1511

goto end;

1512

}

1513

1268

1514

/* Run the main loop */

1269

1515

1270

1516

if(debug){

1299

1545

gpgme_release(mc.ctx);

1300

1546

}

1301

1547

1548

/* Take down the network interface */

1549

if(take_down_interface){

1550

/* Re-raise priviliges */

1551

errno = 0;

1552

ret = seteuid(0);

1553

if(ret == -1){

1554

perror("seteuid");

1555

}

1556

if(geteuid() == 0){

1557

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

1558

if(ret == -1){

1559

perror("ioctl SIOCGIFFLAGS");

1560

} else if(network.ifr_flags & IFF_UP) {

1561

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

1562

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

1563

if(ret == -1){

1564

perror("ioctl SIOCSIFFLAGS");

1565

}

1566

}

1567

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

1568

if(ret == -1){

1569

perror("close");

1570

}

1571

/* Lower privileges permanently */

1572

errno = 0;

1573

ret = setuid(uid);

1574

if(ret == -1){

1575

perror("setuid");

1576

}

1577

}

1578

}

1579

1302

1580

/* Removes the temp directory used by GPGME */

1303

1581

if(tempdir_created){

1304

1582

DIR *d;

1343

1621

}

1344

1622

}

1345

1623

1624

if(quit_now){

1625

sigemptyset(&old_sigterm_action.sa_mask);

1626

old_sigterm_action.sa_handler = SIG_DFL;

1627

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

1628

if(ret == -1){

1629

perror("sigaction");

1630

}

1631

raise(signal_received);

1632

}

1633

1346

1634

return exitcode;

1347

1635

}