/mandos/trunk : revision 370

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

}

472

474

static int init_gnutls_session(gnutls_session_t *session){

473

475

int ret;

474

476

/* GnuTLS session creation */

475

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);

476

480

if(ret != GNUTLS_E_SUCCESS){

477

481

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

478

482

safer_gnutls_strerror(ret));

480

484

481

485

{

482

486

const char *err;

483

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);

484

490

if(ret != GNUTLS_E_SUCCESS){

485

491

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

486

492

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

490

496

}

491

497

}

492

498

493

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

494

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);

495

503

if(ret != GNUTLS_E_SUCCESS){

496

504

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

497

505

safer_gnutls_strerror(ret));

500

508

}

501

509

502

510

/* ignore client certificate if any. */

503

gnutls_certificate_server_set_request(*session,

504

GNUTLS_CERT_IGNORE);

511

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

505

512

506

513

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

507

514

512

519

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

513

520

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

514

521

522

sig_atomic_t quit_now = 0;

523

int signal_received = 0;

524

515

525

/* Called when a Mandos server is found */

516

526

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

517

527

AvahiIfIndex if_index,

518

528

int af){

519

int ret, tcp_sd;

529

int ret, tcp_sd = -1;

520

530

ssize_t sret;

521

531

union {

522

532

struct sockaddr_in in;

526

536

char *decrypted_buffer;

527

537

size_t buffer_length = 0;

528

538

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

530

539

size_t written;

531

540

int retval = 0;

532

541

gnutls_session_t session;

533

542

int pf; /* Protocol family */

534

543

544

if(quit_now){

545

return -1;

546

}

547

535

548

switch(af){

536

549

case AF_INET6:

537

550

pf = PF_INET6;

557

570

tcp_sd = socket(pf, SOCK_STREAM, 0);

558

571

if(tcp_sd < 0){

559

572

perror("socket");

560

return -1;

573

retval = -1;

574

goto mandos_end;

575

}

576

577

if(quit_now){

578

goto mandos_end;

561

579

}

562

580

563

581

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

564

582

if(af == AF_INET6){

565

to.in6.sin6_family = (uint16_t)af;

583

to.in6.sin6_family = (sa_family_t)af;

566

584

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

567

585

} else { /* IPv4 */

568

586

to.in.sin_family = (sa_family_t)af;

570

588

}

571

589

if(ret < 0 ){

572

590

perror("inet_pton");

573

return -1;

591

retval = -1;

592

goto mandos_end;

574

593

}

575

594

if(ret == 0){

576

595

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

577

return -1;

596

retval = -1;

597

goto mandos_end;

578

598

}

579

599

if(af == AF_INET6){

580

600

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

587

607

if(if_index == AVAHI_IF_UNSPEC){

588

608

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

589

609

" without a network interface\n");

590

return -1;

610

retval = -1;

611

goto mandos_end;

591

612

}

592

613

/* Set the network interface number as scope */

593

614

to.in6.sin6_scope_id = (uint32_t)if_index;

598

619

-Wunreachable-code */

599

620

}

600

621

622

if(quit_now){

623

goto mandos_end;

624

}

625

601

626

if(debug){

602

627

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

603

628

char interface[IF_NAMESIZE];

630

655

}

631

656

}

632

657

658

if(quit_now){

659

goto mandos_end;

660

}

661

633

662

if(af == AF_INET6){

634

663

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

635

664

} else {

637

666

}

638

667

if(ret < 0){

639

668

perror("connect");

640

return -1;

669

retval = -1;

670

goto mandos_end;

671

}

672

673

if(quit_now){

674

goto mandos_end;

641

675

}

642

676

643

677

const char *out = mandos_protocol_version;

662

696

break;

663

697

}

664

698

}

699

700

if(quit_now){

701

goto mandos_end;

702

}

665

703

}

666

704

667

705

if(debug){

668

706

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

669

707

}

670

708

709

if(quit_now){

710

goto mandos_end;

711

}

712

671

713

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

672

714

673

do{

715

if(quit_now){

716

goto mandos_end;

717

}

718

719

do {

674

720

ret = gnutls_handshake(session);

721

if(quit_now){

722

goto mandos_end;

723

}

675

724

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

676

725

677

726

if(ret != GNUTLS_E_SUCCESS){

691

740

}

692

741

693

742

while(true){

743

744

if(quit_now){

745

goto mandos_end;

746

}

747

694

748

buffer_capacity = incbuffer(&buffer, buffer_length,

695

749

buffer_capacity);

696

750

if(buffer_capacity == 0){

699

753

goto mandos_end;

700

754

}

701

755

756

if(quit_now){

757

goto mandos_end;

758

}

759

702

760

sret = gnutls_record_recv(session, buffer+buffer_length,

703

761

BUFFER_SIZE);

704

762

if(sret == 0){

710

768

case GNUTLS_E_AGAIN:

711

769

break;

712

770

case GNUTLS_E_REHANDSHAKE:

713

do{

771

do {

714

772

ret = gnutls_handshake(session);

773

774

if(quit_now){

775

goto mandos_end;

776

}

715

777

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

716

778

if(ret < 0){

717

779

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

736

798

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

737

799

}

738

800

801

if(quit_now){

802

goto mandos_end;

803

}

804

739

805

gnutls_bye(session, GNUTLS_SHUT_RDWR);

740

806

807

if(quit_now){

808

goto mandos_end;

809

}

810

741

811

if(buffer_length > 0){

812

ssize_t decrypted_buffer_size;

742

813

decrypted_buffer_size = pgp_packet_decrypt(buffer,

743

814

buffer_length,

744

815

&decrypted_buffer);

745

816

if(decrypted_buffer_size >= 0){

817

746

818

written = 0;

747

819

while(written < (size_t) decrypted_buffer_size){

820

if(quit_now){

821

goto mandos_end;

822

}

823

748

824

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

749

825

(size_t)decrypted_buffer_size - written,

750

826

stdout);

770

846

771

847

mandos_end:

772

848

free(buffer);

773

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

849

if(tcp_sd >= 0){

850

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

851

}

774

852

if(ret == -1){

775

853

perror("close");

776

854

}

777

855

gnutls_deinit(session);

856

if(quit_now){

857

retval = -1;

858

}

778

859

return retval;

779

860

}

780

861

797

878

/* Called whenever a service has been resolved successfully or

798

879

timed out */

799

880

881

if(quit_now){

882

return;

883

}

884

800

885

switch(event){

801

886

default:

802

887

case AVAHI_RESOLVER_FAILURE:

839

924

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

840

925

is removed from the LAN */

841

926

927

if(quit_now){

928

return;

929

}

930

842

931

switch(event){

843

932

default:

844

933

case AVAHI_BROWSER_FAILURE:

873

962

}

874

963

}

875

964

876

sig_atomic_t quit_now = 0;

877

878

965

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

879

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

966

static void handle_sigterm(int sig){

880

967

if(quit_now){

881

968

return;

882

969

}

883

970

quit_now = 1;

971

signal_received = sig;

884

972

int old_errno = errno;

885

973

if(mc.simple_poll != NULL){

886

974

avahi_simple_poll_quit(mc.simple_poll);

897

985

int exitcode = EXIT_SUCCESS;

898

986

const char *interface = "eth0";

899

987

struct ifreq network;

900

int sd;

988

int sd = -1;

989

bool take_down_interface = false;

901

990

uid_t uid;

902

991

gid_t gid;

903

992

char *connect_to = NULL;

911

1000

bool gpgme_initialized = false;

912

1001

float delay = 2.5f;

913

1002

914

struct sigaction old_sigterm_action;

1003

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

915

1004

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

916

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

917

1027

{

918

1028

struct argp_option options[] = {

919

1029

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

1046

1156

exitcode = EXIT_FAILURE;

1047

1157

goto end;

1048

1158

}

1049

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

1050

if(ret == -1){

1051

perror("sigaction");

1052

exitcode = EXIT_FAILURE;

1053

goto end;

1054

}

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

}

1055

1202

1056

1203

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

1057

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

1058

1223

#ifdef __linux__

1059

1224

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1060

1225

messages to mess up the prompt */

1078

1243

}

1079

1244

}

1080

1245

#endif /* __linux__ */

1246

/* Lower privileges */

1247

errno = 0;

1248

ret = seteuid(uid);

1249

if(ret == -1){

1250

perror("seteuid");

1251

}

1081

1252

goto end;

1082

1253

}

1083

1254

strcpy(network.ifr_name, interface);

1093

1264

}

1094

1265

#endif /* __linux__ */

1095

1266

exitcode = EXIT_FAILURE;

1267

/* Lower privileges */

1268

errno = 0;

1269

ret = seteuid(uid);

1270

if(ret == -1){

1271

perror("seteuid");

1272

}

1096

1273

goto end;

1097

1274

}

1098

1275

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

1099

1276

network.ifr_flags |= IFF_UP;

1277

take_down_interface = true;

1100

1278

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

1101

1279

if(ret == -1){

1280

take_down_interface = false;

1102

1281

perror("ioctl SIOCSIFFLAGS");

1103

1282

exitcode = EXIT_FAILURE;

1104

1283

#ifdef __linux__

1109

1288

}

1110

1289

}

1111

1290

#endif /* __linux__ */

1291

/* Lower privileges */

1292

errno = 0;

1293

ret = seteuid(uid);

1294

if(ret == -1){

1295

perror("seteuid");

1296

}

1112

1297

goto end;

1113

1298

}

1114

1299

}

1126

1311

perror("nanosleep");

1127

1312

}

1128

1313

}

1129

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

1130

if(ret == -1){

1131

perror("close");

1314

if(not take_down_interface){

1315

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

1316

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

1317

if(ret == -1){

1318

perror("close");

1319

}

1132

1320

}

1133

1321

#ifdef __linux__

1134

1322

if(restore_loglevel){

1139

1327

}

1140

1328

}

1141

1329

#endif /* __linux__ */

1142

}

1143

1144

uid = getuid();

1145

gid = getgid();

1146

1147

errno = 0;

1148

setgid(gid);

1149

if(ret == -1){

1150

perror("setgid");

1151

}

1152

1153

ret = setuid(uid);

1154

if(ret == -1){

1155

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;

1156

1349

}

1157

1350

1158

1351

ret = init_gnutls_global(pubkey, seckey);

1164

1357

gnutls_initialized = true;

1165

1358

}

1166

1359

1360

if(quit_now){

1361

goto end;

1362

}

1363

1364

tempdir_created = true;

1167

1365

if(mkdtemp(tempdir) == NULL){

1366

tempdir_created = false;

1168

1367

perror("mkdtemp");

1169

1368

goto end;

1170

1369

}

1171

tempdir_created = true;

1370

1371

if(quit_now){

1372

goto end;

1373

}

1172

1374

1173

1375

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

1174

1376

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

1178

1380

gpgme_initialized = true;

1179

1381

}

1180

1382

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

}

1383

if(quit_now){

1384

goto end;

1188

1385

}

1189

1386

1190

1387

if(connect_to != NULL){

1196

1393

exitcode = EXIT_FAILURE;

1197

1394

goto end;

1198

1395

}

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1199

1401

uint16_t port;

1200

1402

errno = 0;

1201

1403

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

1205

1407

exitcode = EXIT_FAILURE;

1206

1408

goto end;

1207

1409

}

1410

1411

if(quit_now){

1412

goto end;

1413

}

1414

1208

1415

port = (uint16_t)tmpmax;

1209

1416

*address = '\0';

1210

1417

address = connect_to;

1215

1422

} else {

1216

1423

af = AF_INET;

1217

1424

}

1425

1426

if(quit_now){

1427

goto end;

1428

}

1429

1218

1430

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

1219

1431

if(ret < 0){

1220

1432

exitcode = EXIT_FAILURE;

1223

1435

}

1224

1436

goto end;

1225

1437

}

1226

1438

1439

if(quit_now){

1440

goto end;

1441

}

1442

1227

1443

{

1228

1444

AvahiServerConfig config;

1229

1445

/* Do not publish any local Zeroconf records */

1250

1466

goto end;

1251

1467

}

1252

1468

1469

if(quit_now){

1470

goto end;

1471

}

1472

1253

1473

/* Create the Avahi service browser */

1254

1474

sb = avahi_s_service_browser_new(mc.server, if_index,

1255

1475

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1261

1481

goto end;

1262

1482

}

1263

1483

1484

if(quit_now){

1485

goto end;

1486

}

1487

1264

1488

/* Run the main loop */

1265

1489

1266

1490

if(debug){

1295

1519

gpgme_release(mc.ctx);

1296

1520

}

1297

1521

1522

/* Take down the network interface */

1523

if(take_down_interface){

1524

/* Re-raise priviliges */

1525

errno = 0;

1526

ret = seteuid(0);

1527

if(ret == -1){

1528

perror("seteuid");

1529

}

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

}

1551

}

1552

}

1553

1298

1554

/* Removes the temp directory used by GPGME */

1299

1555

if(tempdir_created){

1300

1556

DIR *d;

1339

1595

}

1340

1596

}

1341

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

1342

1608

return exitcode;

1343

1609

}