/mandos/trunk : revision 310

30

*/

31

32

/* Needed by GPGME, specifically gpgme_data_seek() */

33

#ifndef _LARGEFILE_SOURCE

34

33

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

34

#define _FILE_OFFSET_BITS 64

38

#endif

39

35

40

36

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

37

42

38

#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror(), remove() */

39

stdout, ferror(), sscanf(),

40

remove() */

44

41

#include <stdint.h> /* uint16_t, uint32_t */

45

42

#include <stddef.h> /* NULL, size_t, ssize_t */

46

43

#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,

47

srand(), strtof() */

44

srand() */

48

45

#include <stdbool.h> /* bool, false, true */

49

46

#include <string.h> /* memset(), strcmp(), strlen(),

50

47

strerror(), asprintf(), strcpy() */

59

56

#include <fcntl.h> /* open() */

60

57

#include <dirent.h> /* opendir(), struct dirent, readdir()

61

58

*/

62

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

63

strtoimax() */

59

#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */

64

60

#include <assert.h> /* assert() */

65

61

#include <errno.h> /* perror(), errno */

66

62

#include <time.h> /* nanosleep(), time() */

71

67

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

68

*/

73

69

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

74

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

70

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

75

71

setgid() */

76

72

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

77

73

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

80

76

argp_parse(), ARGP_KEY_ARG,

81

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

78

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

79

sigaction(), SIGTERM, sigaction,

80

sig_atomic_t */

85

81

86

82

#ifdef __linux__

87

83

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

164

160

*/

165

161

static bool init_gpgme(const char *seckey,

166

162

const char *pubkey, const char *tempdir){

163

int ret;

167

164

gpgme_error_t rc;

168

165

gpgme_engine_info_t engine_info;

169

166

172

169

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

173

170

*/

174

171

bool import_key(const char *filename){

175

int ret;

176

172

int fd;

177

173

gpgme_data_t pgp_data;

178

174

249

245

return false;

250

246

}

251

247

252

return true;

248

return true;

253

249

}

254

250

255

251

/*

309

305

}

310

306

gpgme_recipient_t recipient;

311

307

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;

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

}

320

318

}

321

319

}

322

320

}

514

512

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

515

513

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

516

514

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

515

/* Called when a Mandos server is found */

521

516

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

522

517

AvahiIfIndex if_index,

523

518

int af){

524

int ret, tcp_sd = -1;

519

int ret, tcp_sd;

525

520

ssize_t sret;

526

521

union {

527

522

struct sockaddr_in in;

531

526

char *decrypted_buffer;

532

527

size_t buffer_length = 0;

533

528

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

534

530

size_t written;

535

531

int retval = 0;

536

532

gnutls_session_t session;

537

533

int pf; /* Protocol family */

538

534

539

if(quit_now){

540

return -1;

541

}

542

543

535

switch(af){

544

536

case AF_INET6:

545

537

pf = PF_INET6;

565

557

tcp_sd = socket(pf, SOCK_STREAM, 0);

566

558

if(tcp_sd < 0){

567

559

perror("socket");

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

560

return -1;

574

561

}

575

562

576

563

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

577

564

if(af == AF_INET6){

578

to.in6.sin6_family = (sa_family_t)af;

565

to.in6.sin6_family = (uint16_t)af;

579

566

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

580

567

} else { /* IPv4 */

581

568

to.in.sin_family = (sa_family_t)af;

583

570

}

584

571

if(ret < 0 ){

585

572

perror("inet_pton");

586

retval = -1;

587

goto mandos_end;

573

return -1;

588

574

}

589

575

if(ret == 0){

590

576

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

591

retval = -1;

592

goto mandos_end;

577

return -1;

593

578

}

594

579

if(af == AF_INET6){

595

580

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

602

587

if(if_index == AVAHI_IF_UNSPEC){

603

588

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

604

589

" without a network interface\n");

605

retval = -1;

606

goto mandos_end;

590

return -1;

607

591

}

608

592

/* Set the network interface number as scope */

609

593

to.in6.sin6_scope_id = (uint32_t)if_index;

614

598

-Wunreachable-code */

615

599

}

616

600

617

if(quit_now){

618

goto mandos_end;

619

}

620

621

601

if(debug){

622

602

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

623

603

char interface[IF_NAMESIZE];

650

630

}

651

631

}

652

632

653

if(quit_now){

654

goto mandos_end;

655

}

656

657

633

if(af == AF_INET6){

658

634

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

659

635

} else {

661

637

}

662

638

if(ret < 0){

663

639

perror("connect");

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

640

return -1;

670

641

}

671

642

672

643

const char *out = mandos_protocol_version;

691

662

break;

692

663

}

693

664

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

698

665

}

699

666

700

667

if(debug){

701

668

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

702

669

}

703

670

704

if(quit_now){

705

goto mandos_end;

706

}

707

708

671

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

709

672

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

673

do{

715

674

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

719

675

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

720

676

721

677

if(ret != GNUTLS_E_SUCCESS){

735

691

}

736

692

737

693

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

743

694

buffer_capacity = incbuffer(&buffer, buffer_length,

744

695

buffer_capacity);

745

696

if(buffer_capacity == 0){

748

699

goto mandos_end;

749

700

}

750

701

751

if(quit_now){

752

goto mandos_end;

753

}

754

755

702

sret = gnutls_record_recv(session, buffer+buffer_length,

756

703

BUFFER_SIZE);

757

704

if(sret == 0){

763

710

case GNUTLS_E_AGAIN:

764

711

break;

765

712

case GNUTLS_E_REHANDSHAKE:

766

do {

713

do{

767

714

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

772

715

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

773

716

if(ret < 0){

774

717

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

793

736

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

794

737

}

795

738

796

if(quit_now){

797

goto mandos_end;

798

}

799

800

739

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

740

802

if(quit_now){

803

goto mandos_end;

804

}

805

806

741

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

808

742

decrypted_buffer_size = pgp_packet_decrypt(buffer,

809

743

buffer_length,

810

744

&decrypted_buffer);

811

745

if(decrypted_buffer_size >= 0){

812

813

746

written = 0;

814

747

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

819

748

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

820

749

(size_t)decrypted_buffer_size - written,

821

750

stdout);

841

770

842

771

mandos_end:

843

772

free(buffer);

844

if(tcp_sd >= 0){

845

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

846

}

773

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

847

774

if(ret == -1){

848

775

perror("close");

849

776

}

850

777

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

854

778

return retval;

855

779

}

856

780

873

797

/* Called whenever a service has been resolved successfully or

874

798

timed out */

875

799

876

if(quit_now){

877

return;

878

}

879

880

800

switch(event){

881

801

default:

882

802

case AVAHI_RESOLVER_FAILURE:

919

839

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

920

840

is removed from the LAN */

921

841

922

if(quit_now){

923

return;

924

}

925

926

842

switch(event){

927

843

default:

928

844

case AVAHI_BROWSER_FAILURE:

938

854

the callback function is called the Avahi server will free the

939

855

resolver for us. */

940

856

941

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

942

name, type, domain, protocol, 0,

943

resolve_callback, NULL) == NULL)

857

if(!(avahi_s_service_resolver_new(mc.server, interface,

858

protocol, name, type, domain,

859

AVAHI_PROTO_INET6, 0,

860

resolve_callback, NULL)))

944

861

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

945

862

name, avahi_strerror(avahi_server_errno(mc.server)));

946

863

break;

957

874

}

958

875

}

959

876

877

sig_atomic_t quit_now = 0;

878

960

879

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

961

static void handle_sigterm(int sig){

880

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

962

881

if(quit_now){

963

882

return;

964

883

}

965

884

quit_now = 1;

966

signal_received = sig;

967

885

int old_errno = errno;

968

886

if(mc.simple_poll != NULL){

969

887

avahi_simple_poll_quit(mc.simple_poll);

976

894

int error;

977

895

int ret;

978

896

intmax_t tmpmax;

979

char *tmp;

897

int numchars;

980

898

int exitcode = EXIT_SUCCESS;

981

899

const char *interface = "eth0";

982

900

struct ifreq network;

983

int sd = -1;

984

bool take_down_interface = false;

901

int sd;

985

902

uid_t uid;

986

903

gid_t gid;

987

904

char *connect_to = NULL;

991

908

const char *seckey = PATHDIR "/" SECKEY;

992

909

const char *pubkey = PATHDIR "/" PUBKEY;

993

910

911

/* Initialize Mandos context */

912

mc = (mandos_context){ .simple_poll = NULL, .server = NULL,

913

.dh_bits = 1024, .priority = "SECURE256"

914

":!CTYPE-X.509:+CTYPE-OPENPGP" };

994

915

bool gnutls_initialized = false;

995

916

bool gpgme_initialized = false;

996

float delay = 2.5f;

997

917

double delay = 2.5;

918

998

919

struct sigaction old_sigterm_action;

999

920

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1000

921

1054

975

pubkey = arg;

1055

976

break;

1056

977

case 129: /* --dh-bits */

1057

errno = 0;

1058

tmpmax = strtoimax(arg, &tmp, 10);

1059

if(errno != 0 or tmp == arg or *tmp != '\0'

1060

or tmpmax != (typeof(mc.dh_bits))tmpmax){

978

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

979

if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax

980

or arg[numchars] != '\0'){

1061

981

fprintf(stderr, "Bad number of DH bits\n");

1062

982

exit(EXIT_FAILURE);

1063

983

}

1067

987

mc.priority = arg;

1068

988

break;

1069

989

case 131: /* --delay */

1070

errno = 0;

1071

delay = strtof(arg, &tmp);

1072

if(errno != 0 or tmp == arg or *tmp != '\0'){

990

ret = sscanf(arg, "%lf%n", &delay, &numchars);

991

if(ret < 1 or arg[numchars] != '\0'){

1073

992

fprintf(stderr, "Bad delay\n");

1074

993

exit(EXIT_FAILURE);

1075

994

}

1130

1049

exitcode = EXIT_FAILURE;

1131

1050

goto end;

1132

1051

}

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

}

1052

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

1053

if(ret == -1){

1054

perror("sigaction");

1055

exitcode = EXIT_FAILURE;

1056

goto end;

1057

}

1176

1058

1177

1059

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

1178

1060

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

1190

1061

#ifdef __linux__

1191

1062

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1192

1063

messages to mess up the prompt */

1229

1100

}

1230

1101

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

1231

1102

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1233

1103

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

1234

1104

if(ret == -1){

1235

take_down_interface = false;

1236

1105

perror("ioctl SIOCSIFFLAGS");

1237

1106

exitcode = EXIT_FAILURE;

1238

1107

#ifdef __linux__

1260

1129

perror("nanosleep");

1261

1130

}

1262

1131

}

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

}

1132

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

1133

if(ret == -1){

1134

perror("close");

1269

1135

}

1270

1136

#ifdef __linux__

1271

1137

if(restore_loglevel){

1278

1144

#endif /* __linux__ */

1279

1145

}

1280

1146

1281

if(quit_now){

1282

goto end;

1283

}

1284

1285

1147

uid = getuid();

1286

1148

gid = getgid();

1287

1149

1288

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

1289

1150

errno = 0;

1290

ret = setgid(gid);

1151

setgid(gid);

1291

1152

if(ret == -1){

1292

1153

perror("setgid");

1293

1154

}

1294

1155

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;

1156

ret = setuid(uid);

1157

if(ret == -1){

1158

perror("setuid");

1314

1159

}

1315

1160

1316

1161

ret = init_gnutls_global(pubkey, seckey);

1322

1167

gnutls_initialized = true;

1323

1168

}

1324

1169

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1330

1170

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1332

1171

perror("mkdtemp");

1333

1172

goto end;

1334

1173

}

1335

1336

if(quit_now){

1337

goto end;

1338

}

1174

tempdir_created = true;

1339

1175

1340

1176

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

1341

1177

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

1345

1181

gpgme_initialized = true;

1346

1182

}

1347

1183

1348

if(quit_now){

1349

goto end;

1184

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

1185

if_index = (AvahiIfIndex) if_nametoindex(interface);

1186

if(if_index == 0){

1187

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

1188

exitcode = EXIT_FAILURE;

1189

goto end;

1190

}

1350

1191

}

1351

1192

1352

1193

if(connect_to != NULL){

1358

1199

exitcode = EXIT_FAILURE;

1359

1200

goto end;

1360

1201

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1366

1202

uint16_t port;

1367

errno = 0;

1368

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

1369

if(errno != 0 or tmp == address+1 or *tmp != '\0'

1370

or tmpmax != (uint16_t)tmpmax){

1203

ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);

1204

if(ret < 1 or tmpmax != (uint16_t)tmpmax

1205

or address[numchars+1] != '\0'){

1371

1206

fprintf(stderr, "Bad port number\n");

1372

1207

exitcode = EXIT_FAILURE;

1373

1208

goto end;

1374

1209

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1380

1210

port = (uint16_t)tmpmax;

1381

1211

*address = '\0';

1382

1212

address = connect_to;

1387

1217

} else {

1388

1218

af = AF_INET;

1389

1219

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1395

1220

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

1396

1221

if(ret < 0){

1397

1222

exitcode = EXIT_FAILURE;

1400

1225

}

1401

1226

goto end;

1402

1227

}

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1228

1408

1229

{

1409

1230

AvahiServerConfig config;

1410

1231

/* Do not publish any local Zeroconf records */

1431

1252

goto end;

1432

1253

}

1433

1254

1434

if(quit_now){

1435

goto end;

1436

}

1437

1438

1255

/* Create the Avahi service browser */

1439

1256

sb = avahi_s_service_browser_new(mc.server, if_index,

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1257

AVAHI_PROTO_INET6, "_mandos._tcp",

1441

1258

NULL, 0, browse_callback, NULL);

1442

1259

if(sb == NULL){

1443

1260

fprintf(stderr, "Failed to create service browser: %s\n",

1446

1263

goto end;

1447

1264

}

1448

1265

1449

if(quit_now){

1450

goto end;

1451

}

1452

1453

1266

/* Run the main loop */

1454

1267

1455

1268

if(debug){

1484

1297

gpgme_release(mc.ctx);

1485

1298

}

1486

1299

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

1519

1300

/* Removes the temp directory used by GPGME */

1520

1301

if(tempdir_created){

1521

1302

DIR *d;

1560

1341

}

1561

1342

}

1562

1343

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

1573

1344

return exitcode;

1574

1345

}