/mandos/trunk : revision 370

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

/*

474

static int init_gnutls_session(gnutls_session_t *session){

475

int ret;

476

/* GnuTLS session creation */

477

ret = gnutls_init(session, GNUTLS_SERVER);

477

do {

478

ret = gnutls_init(session, GNUTLS_SERVER);

479

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

478

480

if(ret != GNUTLS_E_SUCCESS){

479

481

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

480

482

safer_gnutls_strerror(ret));

482

484

483

485

{

484

486

const char *err;

485

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

487

do {

488

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

489

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

486

490

if(ret != GNUTLS_E_SUCCESS){

487

491

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

488

492

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

492

496

}

493

497

}

494

498

495

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

496

mc.cred);

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);

497

503

if(ret != GNUTLS_E_SUCCESS){

498

504

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

499

505

safer_gnutls_strerror(ret));

502

508

}

503

509

504

510

/* ignore client certificate if any. */

505

gnutls_certificate_server_set_request(*session,

506

GNUTLS_CERT_IGNORE);

511

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

507

512

508

513

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

509

514

519

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

515

520

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

516

521

522

sig_atomic_t quit_now = 0;

523

int signal_received = 0;

524

517

525

/* Called when a Mandos server is found */

518

526

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

519

527

AvahiIfIndex if_index,

520

528

int af){

521

int ret, tcp_sd;

529

int ret, tcp_sd = -1;

522

530

ssize_t sret;

523

531

union {

524

532

struct sockaddr_in in;

528

536

char *decrypted_buffer;

529

537

size_t buffer_length = 0;

530

538

size_t buffer_capacity = 0;

531

ssize_t decrypted_buffer_size;

532

539

size_t written;

533

540

int retval = 0;

534

541

gnutls_session_t session;

535

542

int pf; /* Protocol family */

536

543

544

if(quit_now){

545

return -1;

546

}

547

537

548

switch(af){

538

549

case AF_INET6:

539

550

pf = PF_INET6;

559

570

tcp_sd = socket(pf, SOCK_STREAM, 0);

560

571

if(tcp_sd < 0){

561

572

perror("socket");

562

return -1;

573

retval = -1;

574

goto mandos_end;

575

}

576

577

if(quit_now){

578

goto mandos_end;

563

579

}

564

580

565

581

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

572

588

}

573

589

if(ret < 0 ){

574

590

perror("inet_pton");

575

return -1;

591

retval = -1;

592

goto mandos_end;

576

593

}

577

594

if(ret == 0){

578

595

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

579

return -1;

596

retval = -1;

597

goto mandos_end;

580

598

}

581

599

if(af == AF_INET6){

582

600

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

589

607

if(if_index == AVAHI_IF_UNSPEC){

590

608

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

591

609

" without a network interface\n");

592

return -1;

610

retval = -1;

611

goto mandos_end;

593

612

}

594

613

/* Set the network interface number as scope */

595

614

to.in6.sin6_scope_id = (uint32_t)if_index;

600

619

-Wunreachable-code */

601

620

}

602

621

622

if(quit_now){

623

goto mandos_end;

624

}

625

603

626

if(debug){

604

627

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

605

628

char interface[IF_NAMESIZE];

632

655

}

633

656

}

634

657

658

if(quit_now){

659

goto mandos_end;

660

}

661

635

662

if(af == AF_INET6){

636

663

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

637

664

} else {

639

666

}

640

667

if(ret < 0){

641

668

perror("connect");

642

return -1;

669

retval = -1;

670

goto mandos_end;

671

}

672

673

if(quit_now){

674

goto mandos_end;

643

675

}

644

676

645

677

const char *out = mandos_protocol_version;

664

696

break;

665

697

}

666

698

}

699

700

if(quit_now){

701

goto mandos_end;

702

}

667

703

}

668

704

669

705

if(debug){

670

706

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

671

707

}

672

708

709

if(quit_now){

710

goto mandos_end;

711

}

712

673

713

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

674

714

675

do{

715

if(quit_now){

716

goto mandos_end;

717

}

718

719

do {

676

720

ret = gnutls_handshake(session);

721

if(quit_now){

722

goto mandos_end;

723

}

677

724

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

678

725

679

726

if(ret != GNUTLS_E_SUCCESS){

693

740

}

694

741

695

742

while(true){

743

744

if(quit_now){

745

goto mandos_end;

746

}

747

696

748

buffer_capacity = incbuffer(&buffer, buffer_length,

697

749

buffer_capacity);

698

750

if(buffer_capacity == 0){

701

753

goto mandos_end;

702

754

}

703

755

756

if(quit_now){

757

goto mandos_end;

758

}

759

704

760

sret = gnutls_record_recv(session, buffer+buffer_length,

705

761

BUFFER_SIZE);

706

762

if(sret == 0){

712

768

case GNUTLS_E_AGAIN:

713

769

break;

714

770

case GNUTLS_E_REHANDSHAKE:

715

do{

771

do {

716

772

ret = gnutls_handshake(session);

773

774

if(quit_now){

775

goto mandos_end;

776

}

717

777

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

718

778

if(ret < 0){

719

779

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

738

798

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

739

799

}

740

800

801

if(quit_now){

802

goto mandos_end;

803

}

804

741

805

gnutls_bye(session, GNUTLS_SHUT_RDWR);

742

806

807

if(quit_now){

808

goto mandos_end;

809

}

810

743

811

if(buffer_length > 0){

812

ssize_t decrypted_buffer_size;

744

813

decrypted_buffer_size = pgp_packet_decrypt(buffer,

745

814

buffer_length,

746

815

&decrypted_buffer);

747

816

if(decrypted_buffer_size >= 0){

817

748

818

written = 0;

749

819

while(written < (size_t) decrypted_buffer_size){

820

if(quit_now){

821

goto mandos_end;

822

}

823

750

824

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

751

825

(size_t)decrypted_buffer_size - written,

752

826

stdout);

772

846

773

847

mandos_end:

774

848

free(buffer);

775

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

849

if(tcp_sd >= 0){

850

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

851

}

776

852

if(ret == -1){

777

853

perror("close");

778

854

}

779

855

gnutls_deinit(session);

856

if(quit_now){

857

retval = -1;

858

}

780

859

return retval;

781

860

}

782

861

799

878

/* Called whenever a service has been resolved successfully or

800

879

timed out */

801

880

881

if(quit_now){

882

return;

883

}

884

802

885

switch(event){

803

886

default:

804

887

case AVAHI_RESOLVER_FAILURE:

841

924

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

842

925

is removed from the LAN */

843

926

927

if(quit_now){

928

return;

929

}

930

844

931

switch(event){

845

932

default:

846

933

case AVAHI_BROWSER_FAILURE:

875

962

}

876

963

}

877

964

878

sig_atomic_t quit_now = 0;

879

880

965

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

881

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

966

static void handle_sigterm(int sig){

882

967

if(quit_now){

883

968

return;

884

969

}

885

970

quit_now = 1;

971

signal_received = sig;

886

972

int old_errno = errno;

887

973

if(mc.simple_poll != NULL){

888

974

avahi_simple_poll_quit(mc.simple_poll);

900

986

const char *interface = "eth0";

901

987

struct ifreq network;

902

988

int sd = -1;

903

bool interface_taken_up = false;

989

bool take_down_interface = false;

904

990

uid_t uid;

905

991

gid_t gid;

906

992

char *connect_to = NULL;

914

1000

bool gpgme_initialized = false;

915

1001

float delay = 2.5f;

916

1002

917

struct sigaction old_sigterm_action;

1003

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

918

1004

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

919

1005

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

920

1027

{

921

1028

struct argp_option options[] = {

922

1029

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

1049

1156

exitcode = EXIT_FAILURE;

1050

1157

goto end;

1051

1158

}

1052

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

1053

if(ret == -1){

1054

perror("sigaction");

1055

exitcode = EXIT_FAILURE;

1056

goto end;

1057

}

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

}

1058

1202

1059

1203

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

1060

1204

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

1061

1223

#ifdef __linux__

1062

1224

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1063

1225

messages to mess up the prompt */

1081

1243

}

1082

1244

}

1083

1245

#endif /* __linux__ */

1246

/* Lower privileges */

1247

errno = 0;

1248

ret = seteuid(uid);

1249

if(ret == -1){

1250

perror("seteuid");

1251

}

1084

1252

goto end;

1085

1253

}

1086

1254

strcpy(network.ifr_name, interface);

1096

1264

}

1097

1265

#endif /* __linux__ */

1098

1266

exitcode = EXIT_FAILURE;

1267

/* Lower privileges */

1268

errno = 0;

1269

ret = seteuid(uid);

1270

if(ret == -1){

1271

perror("seteuid");

1272

}

1099

1273

goto end;

1100

1274

}

1101

1275

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

1102

1276

network.ifr_flags |= IFF_UP;

1277

take_down_interface = true;

1103

1278

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

1104

1279

if(ret == -1){

1280

take_down_interface = false;

1105

1281

perror("ioctl SIOCSIFFLAGS");

1106

1282

exitcode = EXIT_FAILURE;

1107

1283

#ifdef __linux__

1112

1288

}

1113

1289

}

1114

1290

#endif /* __linux__ */

1291

/* Lower privileges */

1292

errno = 0;

1293

ret = seteuid(uid);

1294

if(ret == -1){

1295

perror("seteuid");

1296

}

1115

1297

goto end;

1116

1298

}

1117

interface_taken_up = true;

1118

1299

}

1119

1300

/* sleep checking until interface is running */

1120

1301

for(int i=0; i < delay * 4; i++){

1130

1311

perror("nanosleep");

1131

1312

}

1132

1313

}

1133

if(not interface_taken_up){

1314

if(not take_down_interface){

1315

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

1134

1316

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

1135

1317

if(ret == -1){

1136

1318

perror("close");

1145

1327

}

1146

1328

}

1147

1329

#endif /* __linux__ */

1148

}

1149

1150

uid = getuid();

1151

gid = getgid();

1152

1153

errno = 0;

1154

setgid(gid);

1155

if(ret == -1){

1156

perror("setgid");

1157

}

1158

1159

ret = setuid(uid);

1160

if(ret == -1){

1161

perror("setuid");

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;

1162

1349

}

1163

1350

1164

1351

ret = init_gnutls_global(pubkey, seckey);

1170

1357

gnutls_initialized = true;

1171

1358

}

1172

1359

1360

if(quit_now){

1361

goto end;

1362

}

1363

1364

tempdir_created = true;

1173

1365

if(mkdtemp(tempdir) == NULL){

1366

tempdir_created = false;

1174

1367

perror("mkdtemp");

1175

1368

goto end;

1176

1369

}

1177

tempdir_created = true;

1370

1371

if(quit_now){

1372

goto end;

1373

}

1178

1374

1179

1375

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

1180

1376

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

1184

1380

gpgme_initialized = true;

1185

1381

}

1186

1382

1187

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

1188

if_index = (AvahiIfIndex) if_nametoindex(interface);

1189

if(if_index == 0){

1190

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

1191

exitcode = EXIT_FAILURE;

1192

goto end;

1193

}

1383

if(quit_now){

1384

goto end;

1194

1385

}

1195

1386

1196

1387

if(connect_to != NULL){

1202

1393

exitcode = EXIT_FAILURE;

1203

1394

goto end;

1204

1395

}

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1205

1401

uint16_t port;

1206

1402

errno = 0;

1207

1403

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

1211

1407

exitcode = EXIT_FAILURE;

1212

1408

goto end;

1213

1409

}

1410

1411

if(quit_now){

1412

goto end;

1413

}

1414

1214

1415

port = (uint16_t)tmpmax;

1215

1416

*address = '\0';

1216

1417

address = connect_to;

1221

1422

} else {

1222

1423

af = AF_INET;

1223

1424

}

1425

1426

if(quit_now){

1427

goto end;

1428

}

1429

1224

1430

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

1225

1431

if(ret < 0){

1226

1432

exitcode = EXIT_FAILURE;

1229

1435

}

1230

1436

goto end;

1231

1437

}

1232

1438

1439

if(quit_now){

1440

goto end;

1441

}

1442

1233

1443

{

1234

1444

AvahiServerConfig config;

1235

1445

/* Do not publish any local Zeroconf records */

1256

1466

goto end;

1257

1467

}

1258

1468

1469

if(quit_now){

1470

goto end;

1471

}

1472

1259

1473

/* Create the Avahi service browser */

1260

1474

sb = avahi_s_service_browser_new(mc.server, if_index,

1261

1475

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1267

1481

goto end;

1268

1482

}

1269

1483

1484

if(quit_now){

1485

goto end;

1486

}

1487

1270

1488

/* Run the main loop */

1271

1489

1272

1490

if(debug){

1302

1520

}

1303

1521

1304

1522

/* Take down the network interface */

1305

if(interface_taken_up){

1306

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

1523

if(take_down_interface){

1524

/* Re-raise priviliges */

1525

errno = 0;

1526

ret = seteuid(0);

1307

1527

if(ret == -1){

1308

perror("ioctl SIOCGIFFLAGS");

1309

} else if(network.ifr_flags & IFF_UP) {

1310

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

1311

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

1312

if(ret == -1){

1313

perror("ioctl SIOCSIFFLAGS");

1314

}

1528

perror("seteuid");

1315

1529

}

1316

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

1317

if(ret == -1){

1318

perror("close");

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

}

1319

1551

}

1320

1552

}

1321

1553

1363

1595

}

1364

1596

}

1365

1597

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

1366

1608

return exitcode;

1367

1609

}