/mandos/trunk : revision 318

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

73

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

74

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

74

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

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, sig_atomic_t,

84

raise() */

83

sigaction(), SIGTERM, sigaction,

84

sig_atomic_t */

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;

167

168

gpgme_error_t rc;

168

169

gpgme_engine_info_t engine_info;

169

170

172

173

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

173

174

*/

174

175

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

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;

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

}

320

322

}

321

323

}

322

324

}

474

476

static int init_gnutls_session(gnutls_session_t *session){

475

477

int ret;

476

478

/* GnuTLS session creation */

477

do {

478

ret = gnutls_init(session, GNUTLS_SERVER);

479

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

479

ret = gnutls_init(session, GNUTLS_SERVER);

480

if(ret != GNUTLS_E_SUCCESS){

481

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

482

safer_gnutls_strerror(ret));

484

485

{

486

const char *err;

487

do {

488

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

489

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

487

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

490

488

if(ret != GNUTLS_E_SUCCESS){

491

489

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

492

490

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

496

494

}

497

495

}

498

496

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

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

498

mc.cred);

503

499

if(ret != GNUTLS_E_SUCCESS){

504

500

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

505

501

safer_gnutls_strerror(ret));

508

504

}

509

505

510

506

/* ignore client certificate if any. */

511

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

507

gnutls_certificate_server_set_request(*session,

508

GNUTLS_CERT_IGNORE);

512

509

513

510

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

514

511

519

516

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

520

517

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

521

518

522

sig_atomic_t quit_now = 0;

523

int signal_received = 0;

524

525

519

/* Called when a Mandos server is found */

526

520

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

527

521

AvahiIfIndex if_index,

528

522

int af){

529

int ret, tcp_sd = -1;

523

int ret, tcp_sd;

530

524

ssize_t sret;

531

525

union {

532

526

struct sockaddr_in in;

536

530

char *decrypted_buffer;

537

531

size_t buffer_length = 0;

538

532

size_t buffer_capacity = 0;

533

ssize_t decrypted_buffer_size;

539

534

size_t written;

540

535

int retval = 0;

541

536

gnutls_session_t session;

542

537

int pf; /* Protocol family */

543

538

544

if(quit_now){

545

return -1;

546

}

547

548

539

switch(af){

549

540

case AF_INET6:

550

541

pf = PF_INET6;

570

561

tcp_sd = socket(pf, SOCK_STREAM, 0);

571

562

if(tcp_sd < 0){

572

563

perror("socket");

573

retval = -1;

574

goto mandos_end;

575

}

576

577

if(quit_now){

578

goto mandos_end;

564

return -1;

579

565

}

580

566

581

567

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

582

568

if(af == AF_INET6){

583

to.in6.sin6_family = (sa_family_t)af;

569

to.in6.sin6_family = (uint16_t)af;

584

570

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

585

571

} else { /* IPv4 */

586

572

to.in.sin_family = (sa_family_t)af;

588

574

}

589

575

if(ret < 0 ){

590

576

perror("inet_pton");

591

retval = -1;

592

goto mandos_end;

577

return -1;

593

578

}

594

579

if(ret == 0){

595

580

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

596

retval = -1;

597

goto mandos_end;

581

return -1;

598

582

}

599

583

if(af == AF_INET6){

600

584

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

607

591

if(if_index == AVAHI_IF_UNSPEC){

608

592

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

609

593

" without a network interface\n");

610

retval = -1;

611

goto mandos_end;

594

return -1;

612

595

}

613

596

/* Set the network interface number as scope */

614

597

to.in6.sin6_scope_id = (uint32_t)if_index;

619

602

-Wunreachable-code */

620

603

}

621

604

622

if(quit_now){

623

goto mandos_end;

624

}

625

626

605

if(debug){

627

606

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

628

607

char interface[IF_NAMESIZE];

655

634

}

656

635

}

657

636

658

if(quit_now){

659

goto mandos_end;

660

}

661

662

637

if(af == AF_INET6){

663

638

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

664

639

} else {

666

641

}

667

642

if(ret < 0){

668

643

perror("connect");

669

retval = -1;

670

goto mandos_end;

671

}

672

673

if(quit_now){

674

goto mandos_end;

644

return -1;

675

645

}

676

646

677

647

const char *out = mandos_protocol_version;

696

666

break;

697

667

}

698

668

}

699

700

if(quit_now){

701

goto mandos_end;

702

}

703

669

}

704

670

705

671

if(debug){

706

672

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

707

673

}

708

674

709

if(quit_now){

710

goto mandos_end;

711

}

712

713

675

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

714

676

715

if(quit_now){

716

goto mandos_end;

717

}

718

719

do {

677

do{

720

678

ret = gnutls_handshake(session);

721

if(quit_now){

722

goto mandos_end;

723

}

724

679

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

725

680

726

681

if(ret != GNUTLS_E_SUCCESS){

740

695

}

741

696

742

697

while(true){

743

744

if(quit_now){

745

goto mandos_end;

746

}

747

748

698

buffer_capacity = incbuffer(&buffer, buffer_length,

749

699

buffer_capacity);

750

700

if(buffer_capacity == 0){

753

703

goto mandos_end;

754

704

}

755

705

756

if(quit_now){

757

goto mandos_end;

758

}

759

760

706

sret = gnutls_record_recv(session, buffer+buffer_length,

761

707

BUFFER_SIZE);

762

708

if(sret == 0){

768

714

case GNUTLS_E_AGAIN:

769

715

break;

770

716

case GNUTLS_E_REHANDSHAKE:

771

do {

717

do{

772

718

ret = gnutls_handshake(session);

773

774

if(quit_now){

775

goto mandos_end;

776

}

777

719

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

778

720

if(ret < 0){

779

721

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

798

740

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

799

741

}

800

742

801

if(quit_now){

802

goto mandos_end;

803

}

804

805

743

gnutls_bye(session, GNUTLS_SHUT_RDWR);

806

744

807

if(quit_now){

808

goto mandos_end;

809

}

810

811

745

if(buffer_length > 0){

812

ssize_t decrypted_buffer_size;

813

746

decrypted_buffer_size = pgp_packet_decrypt(buffer,

814

747

buffer_length,

815

748

&decrypted_buffer);

816

749

if(decrypted_buffer_size >= 0){

817

818

750

written = 0;

819

751

while(written < (size_t) decrypted_buffer_size){

820

if(quit_now){

821

goto mandos_end;

822

}

823

824

752

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

825

753

(size_t)decrypted_buffer_size - written,

826

754

stdout);

846

774

847

775

mandos_end:

848

776

free(buffer);

849

if(tcp_sd >= 0){

850

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

851

}

777

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

852

778

if(ret == -1){

853

779

perror("close");

854

780

}

855

781

gnutls_deinit(session);

856

if(quit_now){

857

retval = -1;

858

}

859

782

return retval;

860

783

}

861

784

878

801

/* Called whenever a service has been resolved successfully or

879

802

timed out */

880

803

881

if(quit_now){

882

return;

883

}

884

885

804

switch(event){

886

805

default:

887

806

case AVAHI_RESOLVER_FAILURE:

924

843

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

925

844

is removed from the LAN */

926

845

927

if(quit_now){

928

return;

929

}

930

931

846

switch(event){

932

847

default:

933

848

case AVAHI_BROWSER_FAILURE:

962

877

}

963

878

}

964

879

880

sig_atomic_t quit_now = 0;

881

965

882

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

966

static void handle_sigterm(int sig){

883

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

967

884

if(quit_now){

968

885

return;

969

886

}

970

887

quit_now = 1;

971

signal_received = sig;

972

888

int old_errno = errno;

973

889

if(mc.simple_poll != NULL){

974

890

avahi_simple_poll_quit(mc.simple_poll);

985

901

int exitcode = EXIT_SUCCESS;

986

902

const char *interface = "eth0";

987

903

struct ifreq network;

988

int sd = -1;

989

bool take_down_interface = false;

904

int sd;

990

905

uid_t uid;

991

906

gid_t gid;

992

907

char *connect_to = NULL;

1000

915

bool gpgme_initialized = false;

1001

916

float delay = 2.5f;

1002

917

1003

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

918

struct sigaction old_sigterm_action;

1004

919

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1005

920

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

1027

921

{

1028

922

struct argp_option options[] = {

1029

923

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

1156

1050

exitcode = EXIT_FAILURE;

1157

1051

goto end;

1158

1052

}

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

}

1053

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

1054

if(ret == -1){

1055

perror("sigaction");

1056

exitcode = EXIT_FAILURE;

1057

goto end;

1058

}

1202

1059

1203

1060

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

1204

1061

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

1223

1062

#ifdef __linux__

1224

1063

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1225

1064

messages to mess up the prompt */

1243

1082

}

1244

1083

}

1245

1084

#endif /* __linux__ */

1246

/* Lower privileges */

1247

errno = 0;

1248

ret = seteuid(uid);

1249

if(ret == -1){

1250

perror("seteuid");

1251

}

1252

1085

goto end;

1253

1086

}

1254

1087

strcpy(network.ifr_name, interface);

1264

1097

}

1265

1098

#endif /* __linux__ */

1266

1099

exitcode = EXIT_FAILURE;

1267

/* Lower privileges */

1268

errno = 0;

1269

ret = seteuid(uid);

1270

if(ret == -1){

1271

perror("seteuid");

1272

}

1273

1100

goto end;

1274

1101

}

1275

1102

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

1276

1103

network.ifr_flags |= IFF_UP;

1277

take_down_interface = true;

1278

1104

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

1279

1105

if(ret == -1){

1280

take_down_interface = false;

1281

1106

perror("ioctl SIOCSIFFLAGS");

1282

1107

exitcode = EXIT_FAILURE;

1283

1108

#ifdef __linux__

1288

1113

}

1289

1114

}

1290

1115

#endif /* __linux__ */

1291

/* Lower privileges */

1292

errno = 0;

1293

ret = seteuid(uid);

1294

if(ret == -1){

1295

perror("seteuid");

1296

}

1297

1116

goto end;

1298

1117

}

1299

1118

}

1311

1130

perror("nanosleep");

1312

1131

}

1313

1132

}

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

}

1133

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

1134

if(ret == -1){

1135

perror("close");

1320

1136

}

1321

1137

#ifdef __linux__

1322

1138

if(restore_loglevel){

1327

1143

}

1328

1144

}

1329

1145

#endif /* __linux__ */

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;

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");

1349

1160

}

1350

1161

1351

1162

ret = init_gnutls_global(pubkey, seckey);

1357

1168

gnutls_initialized = true;

1358

1169

}

1359

1170

1360

if(quit_now){

1361

goto end;

1362

}

1363

1364

tempdir_created = true;

1365

1171

if(mkdtemp(tempdir) == NULL){

1366

tempdir_created = false;

1367

1172

perror("mkdtemp");

1368

1173

goto end;

1369

1174

}

1370

1371

if(quit_now){

1372

goto end;

1373

}

1175

tempdir_created = true;

1374

1176

1375

1177

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

1376

1178

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

1380

1182

gpgme_initialized = true;

1381

1183

}

1382

1184

1383

if(quit_now){

1384

goto end;

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

}

1385

1192

}

1386

1193

1387

1194

if(connect_to != NULL){

1393

1200

exitcode = EXIT_FAILURE;

1394

1201

goto end;

1395

1202

}

1396

1397

if(quit_now){

1398

goto end;

1399

}

1400

1401

1203

uint16_t port;

1402

1204

errno = 0;

1403

1205

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

1407

1209

exitcode = EXIT_FAILURE;

1408

1210

goto end;

1409

1211

}

1410

1411

if(quit_now){

1412

goto end;

1413

}

1414

1415

1212

port = (uint16_t)tmpmax;

1416

1213

*address = '\0';

1417

1214

address = connect_to;

1422

1219

} else {

1423

1220

af = AF_INET;

1424

1221

}

1425

1426

if(quit_now){

1427

goto end;

1428

}

1429

1430

1222

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

1431

1223

if(ret < 0){

1432

1224

exitcode = EXIT_FAILURE;

1435

1227

}

1436

1228

goto end;

1437

1229

}

1438

1439

if(quit_now){

1440

goto end;

1441

}

1442

1230

1443

1231

{

1444

1232

AvahiServerConfig config;

1445

1233

/* Do not publish any local Zeroconf records */

1466

1254

goto end;

1467

1255

}

1468

1256

1469

if(quit_now){

1470

goto end;

1471

}

1472

1473

1257

/* Create the Avahi service browser */

1474

1258

sb = avahi_s_service_browser_new(mc.server, if_index,

1475

1259

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1481

1265

goto end;

1482

1266

}

1483

1267

1484

if(quit_now){

1485

goto end;

1486

}

1487

1488

1268

/* Run the main loop */

1489

1269

1490

1270

if(debug){

1519

1299

gpgme_release(mc.ctx);

1520

1300

}

1521

1301

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

1554

1302

/* Removes the temp directory used by GPGME */

1555

1303

if(tempdir_created){

1556

1304

DIR *d;

1595

1343

}

1596

1344

}

1597

1345

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

1608

1346

return exitcode;

1609

1347

}