/mandos/release : revision 237.2.169

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

srand(), strtof(), abort() */

46

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

47

strtof(), abort() */

48

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

49

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

50

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

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

86

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

85

87

86

88

#ifdef __linux__

87

89

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

125

127

static const char mandos_protocol_version[] = "1";

126

128

const char *argp_program_version = "mandos-client " VERSION;

127

129

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

128

static const char sys_class_net[] = "/sys/class/net";

129

char *connect_to = NULL;

130

131

/* Used for passing in values through the Avahi callback functions */

132

typedef struct {

554

gnutls_session_t session;

555

int pf; /* Protocol family */

556

557

errno = 0;

558

557

559

if(quit_now){

560

errno = EINTR;

558

561

return -1;

559

562

}

560

563

567

570

break;

568

571

default:

569

572

fprintf(stderr, "Bad address family: %d\n", af);

573

errno = EINVAL;

570

574

return -1;

571

575

}

572

576

582

586

583

587

tcp_sd = socket(pf, SOCK_STREAM, 0);

584

588

if(tcp_sd < 0){

589

int e = errno;

585

590

perror("socket");

591

errno = e;

586

592

goto mandos_end;

587

593

}

588

594

589

595

if(quit_now){

596

errno = EINTR;

590

597

goto mandos_end;

591

598

}

592

599

606

ret = inet_pton(af, ip, &to.in.sin_addr);

600

607

}

601

608

if(ret < 0 ){

609

int e = errno;

602

610

perror("inet_pton");

611

errno = e;

603

612

goto mandos_end;

604

613

}

605

614

if(ret == 0){

615

int e = errno;

606

616

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

617

errno = e;

607

618

goto mandos_end;

608

619

}

609

620

if(af == AF_INET6){

617

628

if(if_index == AVAHI_IF_UNSPEC){

618

629

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

619

630

" without a network interface\n");

631

errno = EINVAL;

620

632

goto mandos_end;

621

633

}

622

634

/* Set the network interface number as scope */

629

641

}

630

642

631

643

if(quit_now){

644

errno = EINTR;

632

645

goto mandos_end;

633

646

}

634

647

665

678

}

666

679

667

680

if(quit_now){

681

errno = EINTR;

668

682

goto mandos_end;

669

683

}

670

684

674

688

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

675

689

}

676

690

if(ret < 0){

691

int e = errno;

677

692

perror("connect");

693

errno = e;

678

694

goto mandos_end;

679

695

}

680

696

681

697

if(quit_now){

698

errno = EINTR;

682

699

goto mandos_end;

683

700

}

684

701

689

706

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

690

707

out_size - written));

691

708

if(ret == -1){

709

int e = errno;

692

710

perror("write");

711

errno = e;

693

712

goto mandos_end;

694

713

}

695

714

written += (size_t)ret;

705

724

}

706

725

707

726

if(quit_now){

727

errno = EINTR;

708

728

goto mandos_end;

709

729

}

710

730

}

714

734

}

715

735

716

736

if(quit_now){

737

errno = EINTR;

717

738

goto mandos_end;

718

739

}

719

740

720

741

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

721

742

722

743

if(quit_now){

744

errno = EINTR;

723

745

goto mandos_end;

724

746

}

725

747

726

748

do {

727

749

ret = gnutls_handshake(session);

728

750

if(quit_now){

751

errno = EINTR;

729

752

goto mandos_end;

730

753

}

731

754

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

735

758

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

736

759

gnutls_perror(ret);

737

760

}

761

errno = EPROTO;

738

762

goto mandos_end;

739

763

}

740

764

748

772

while(true){

749

773

750

774

if(quit_now){

775

errno = EINTR;

751

776

goto mandos_end;

752

777

}

753

778

754

779

buffer_capacity = incbuffer(&buffer, buffer_length,

755

780

buffer_capacity);

756

781

if(buffer_capacity == 0){

782

int e = errno;

757

783

perror("incbuffer");

784

errno = e;

758

785

goto mandos_end;

759

786

}

760

787

761

788

if(quit_now){

789

errno = EINTR;

762

790

goto mandos_end;

763

791

}

764

792

777

805

ret = gnutls_handshake(session);

778

806

779

807

if(quit_now){

808

errno = EINTR;

780

809

goto mandos_end;

781

810

}

782

811

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

783

812

if(ret < 0){

784

813

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

785

814

gnutls_perror(ret);

815

errno = EPROTO;

786

816

goto mandos_end;

787

817

}

788

818

break;

790

820

fprintf(stderr, "Unknown error while reading data from"

791

821

" encrypted session with Mandos server\n");

792

822

gnutls_bye(session, GNUTLS_SHUT_RDWR);

823

errno = EIO;

793

824

goto mandos_end;

794

825

}

795

826

} else {

802

833

}

803

834

804

835

if(quit_now){

836

errno = EINTR;

805

837

goto mandos_end;

806

838

}

807

839

808

840

do {

809

841

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

810

842

if(quit_now){

843

errno = EINTR;

811

844

goto mandos_end;

812

845

}

813

846

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

822

855

written = 0;

823

856

while(written < (size_t) decrypted_buffer_size){

824

857

if(quit_now){

858

errno = EINTR;

825

859

goto mandos_end;

826

860

}

827

861

829

863

(size_t)decrypted_buffer_size - written,

830

864

stdout);

831

865

if(ret == 0 and ferror(stdout)){

866

int e = errno;

832

867

if(debug){

833

868

fprintf(stderr, "Error writing encrypted data: %s\n",

834

869

strerror(errno));

835

870

}

871

errno = e;

836

872

goto mandos_end;

837

873

}

838

874

written += (size_t)ret;

844

880

/* Shutdown procedure */

845

881

846

882

mandos_end:

847

free(decrypted_buffer);

848

free(buffer);

849

if(tcp_sd >= 0){

850

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

851

}

852

if(ret == -1){

853

perror("close");

854

}

855

gnutls_deinit(session);

856

if(quit_now){

857

retval = -1;

883

{

884

int e = errno;

885

free(decrypted_buffer);

886

free(buffer);

887

if(tcp_sd >= 0){

888

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

889

}

890

if(ret == -1){

891

if(e == 0){

892

e = errno;

893

}

894

perror("close");

895

}

896

gnutls_deinit(session);

897

if(quit_now){

898

e = EINTR;

899

retval = -1;

900

}

901

errno = e;

858

902

}

859

903

return retval;

860

904

}

976

1020

errno = old_errno;

977

1021

}

978

1022

979

/*

980

* This function determines if a directory entry in /sys/class/net

981

* corresponds to an acceptable network device.

982

* (This function is passed to scandir(3) as a filter function.)

983

*/

984

int good_interface(const struct dirent *if_entry){

985

ssize_t ssret;

986

char *flagname = NULL;

987

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

988

if_entry->d_name);

989

if(ret < 0){

990

perror("asprintf");

991

return 0;

992

}

993

if(if_entry->d_name[0] == '.'){

994

return 0;

995

}

996

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

997

if(flags_fd == -1){

998

perror("open");

999

return 0;

1000

}

1001

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1002

/* read line from flags_fd */

1003

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1004

char *flagstring = malloc((size_t)to_read);

1005

if(flagstring == NULL){

1006

perror("malloc");

1007

close(flags_fd);

1008

return 0;

1009

}

1010

while(to_read > 0){

1011

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1012

(size_t)to_read));

1013

if(ssret == -1){

1014

perror("read");

1015

free(flagstring);

1016

close(flags_fd);

1017

return 0;

1018

}

1019

to_read -= ssret;

1020

if(ssret == 0){

1021

break;

1022

}

1023

}

1024

close(flags_fd);

1025

intmax_t tmpmax;

1026

char *tmp;

1027

errno = 0;

1028

tmpmax = strtoimax(flagstring, &tmp, 0);

1029

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

1030

and not (isspace(*tmp)))

1031

or tmpmax != (ifreq_flags)tmpmax){

1032

free(flagstring);

1033

return 0;

1034

}

1035

free(flagstring);

1036

ifreq_flags flags = (ifreq_flags)tmpmax;

1037

/* Reject the loopback device */

1038

if(flags & IFF_LOOPBACK){

1039

return 0;

1040

}

1041

/* Accept point-to-point devices only if connect_to is specified */

1042

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1043

return 1;

1044

}

1045

/* Otherwise, reject non-broadcast-capable devices */

1046

if(not (flags & IFF_BROADCAST)){

1047

return 0;

1048

}

1049

/* Accept this device */

1050

return 1;

1051

}

1052

1053

1023

int main(int argc, char *argv[]){

1054

1024

AvahiSServiceBrowser *sb = NULL;

1055

1025

int error;

1057

1027

intmax_t tmpmax;

1058

1028

char *tmp;

1059

1029

int exitcode = EXIT_SUCCESS;

1060

const char *interface = "";

1030

const char *interface = "eth0";

1061

1031

struct ifreq network;

1062

1032

int sd = -1;

1063

1033

bool take_down_interface = false;

1064

1034

uid_t uid;

1065

1035

gid_t gid;

1036

char *connect_to = NULL;

1066

1037

char tempdir[] = "/tmp/mandosXXXXXX";

1067

1038

bool tempdir_created = false;

1068

1039

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1131

1102

.arg = "SECONDS",

1132

1103

.doc = "Maximum delay to wait for interface startup",

1133

1104

.group = 2 },

1105

/*

1106

* These reproduce what we would get without ARGP_NO_HELP

1107

*/

1108

{ .name = "help", .key = '?',

1109

.doc = "Give this help list", .group = -1 },

1110

{ .name = "usage", .key = -3,

1111

.doc = "Give a short usage message", .group = -1 },

1112

{ .name = "version", .key = 'V',

1113

.doc = "Print program version", .group = -1 },

1134

1114

{ .name = NULL }

1135

1115

};

1136

1116

1137

1117

error_t parse_opt(int key, char *arg,

1138

1118

struct argp_state *state){

1119

errno = 0;

1139

1120

switch(key){

1140

1121

case 128: /* --debug */

1141

1122

debug = true;

1157

1138

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

1158

1139

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

1159

1140

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

1160

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

1161

exit(EXIT_FAILURE);

1141

argp_error(state, "Bad number of DH bits");

1162

1142

}

1163

1143

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

1164

1144

break;

1169

1149

errno = 0;

1170

1150

delay = strtof(arg, &tmp);

1171

1151

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

1172

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

1173

exit(EXIT_FAILURE);

1152

argp_error(state, "Bad delay");

1174

1153

}

1175

1154

break;

1176

case ARGP_KEY_ARG:

1177

argp_usage(state);

1178

case ARGP_KEY_END:

1155

/*

1156

* These reproduce what we would get without ARGP_NO_HELP

1157

*/

1158

case '?': /* --help */

1159

argp_state_help(state, state->out_stream,

1160

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1161

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1162

case -3: /* --usage */

1163

argp_state_help(state, state->out_stream,

1164

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1165

case 'V': /* --version */

1166

fprintf(state->out_stream, "%s\n", argp_program_version);

1167

exit(argp_err_exit_status);

1179

1168

break;

1180

1169

default:

1181

1170

return ARGP_ERR_UNKNOWN;

1182

1171

}

1183

return 0;

1172

return errno;

1184

1173

}

1185

1174

1186

1175

struct argp argp = { .options = options, .parser = parse_opt,

1187

1176

.args_doc = "",

1188

1177

.doc = "Mandos client -- Get and decrypt"

1189

1178

" passwords from a Mandos server" };

1190

ret = argp_parse(&argp, argc, argv, 0, 0, NULL);

1191

if(ret == ARGP_ERR_UNKNOWN){

1192

fprintf(stderr, "Unknown error while parsing arguments\n");

1193

exitcode = EXIT_FAILURE;

1179

ret = argp_parse(&argp, argc, argv,

1180

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1181

switch(ret){

1182

case 0:

1183

break;

1184

case ENOMEM:

1185

default:

1186

errno = ret;

1187

perror("argp_parse");

1188

exitcode = EX_OSERR;

1189

goto end;

1190

case EINVAL:

1191

exitcode = EX_USAGE;

1194

1192

goto end;

1195

1193

}

1196

1194

}

1198

1196

if(not debug){

1199

1197

avahi_set_log_function(empty_log);

1200

1198

}

1201

1202

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

1203

struct dirent **direntries;

1204

ret = scandir(sys_class_net, &direntries, good_interface,

1205

alphasort);

1206

if(ret >= 1){

1207

/* Pick the first good interface */

1208

interface = strdup(direntries[0]->d_name);

1209

if(interface == NULL){

1210

perror("malloc");

1211

free(direntries);

1212

exitcode = EXIT_FAILURE;

1213

goto end;

1214

}

1215

free(direntries);

1216

} else {

1217

free(direntries);

1218

fprintf(stderr, "Could not find a network interface\n");

1219

exitcode = EXIT_FAILURE;

1220

goto end;

1221

}

1222

}

1223

1199

1224

1200

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1225

1201

from the signal handler */

1228

1204

mc.simple_poll = avahi_simple_poll_new();

1229

1205

if(mc.simple_poll == NULL){

1230

1206

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1231

exitcode = EXIT_FAILURE;

1207

exitcode = EX_UNAVAILABLE;

1232

1208

goto end;

1233

1209

}

1234

1210

1236

1212

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1237

1213

if(ret == -1){

1238

1214

perror("sigaddset");

1239

exitcode = EXIT_FAILURE;

1215

exitcode = EX_OSERR;

1240

1216

goto end;

1241

1217

}

1242

1218

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1243

1219

if(ret == -1){

1244

1220

perror("sigaddset");

1245

exitcode = EXIT_FAILURE;

1221

exitcode = EX_OSERR;

1246

1222

goto end;

1247

1223

}

1248

1224

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1249

1225

if(ret == -1){

1250

1226

perror("sigaddset");

1251

exitcode = EXIT_FAILURE;

1227

exitcode = EX_OSERR;

1252

1228

goto end;

1253

1229

}

1254

1230

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

1258

1234

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

1259

1235

if(ret == -1){

1260

1236

perror("sigaction");

1261

return EXIT_FAILURE;

1237

return EX_OSERR;

1262

1238

}

1263

1239

if(old_sigterm_action.sa_handler != SIG_IGN){

1264

1240

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

1265

1241

if(ret == -1){

1266

1242

perror("sigaction");

1267

exitcode = EXIT_FAILURE;

1243

exitcode = EX_OSERR;

1268

1244

goto end;

1269

1245

}

1270

1246

}

1271

1247

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

1272

1248

if(ret == -1){

1273

1249

perror("sigaction");

1274

return EXIT_FAILURE;

1250

return EX_OSERR;

1275

1251

}

1276

1252

if(old_sigterm_action.sa_handler != SIG_IGN){

1277

1253

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

1278

1254

if(ret == -1){

1279

1255

perror("sigaction");

1280

exitcode = EXIT_FAILURE;

1256

exitcode = EX_OSERR;

1281

1257

goto end;

1282

1258

}

1283

1259

}

1284

1260

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

1285

1261

if(ret == -1){

1286

1262

perror("sigaction");

1287

return EXIT_FAILURE;

1263

return EX_OSERR;

1288

1264

}

1289

1265

if(old_sigterm_action.sa_handler != SIG_IGN){

1290

1266

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

1291

1267

if(ret == -1){

1292

1268

perror("sigaction");

1293

exitcode = EXIT_FAILURE;

1269

exitcode = EX_OSERR;

1294

1270

goto end;

1295

1271

}

1296

1272

}

1297

1273

1298

1274

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

1299

if(strcmp(interface, "none") != 0){

1275

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

1300

1276

if_index = (AvahiIfIndex) if_nametoindex(interface);

1301

1277

if(if_index == 0){

1302

1278

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

1303

exitcode = EXIT_FAILURE;

1279

exitcode = EX_UNAVAILABLE;

1304

1280

goto end;

1305

1281

}

1306

1282

1317

1293

1318

1294

#ifdef __linux__

1319

1295

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1320

messages to mess up the prompt */

1296

messages about the network interface to mess up the prompt */

1321

1297

ret = klogctl(8, NULL, 5);

1322

1298

bool restore_loglevel = true;

1323

1299

if(ret == -1){

1329

1305

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1330

1306

if(sd < 0){

1331

1307

perror("socket");

1332

exitcode = EXIT_FAILURE;

1308

exitcode = EX_OSERR;

1333

1309

#ifdef __linux__

1334

1310

if(restore_loglevel){

1335

1311

ret = klogctl(7, NULL, 0);

1358

1334

}

1359

1335

}

1360

1336

#endif /* __linux__ */

1361

exitcode = EXIT_FAILURE;

1337

exitcode = EX_OSERR;

1362

1338

/* Lower privileges */

1363

1339

errno = 0;

1364

1340

ret = seteuid(uid);

1374

1350

if(ret == -1){

1375

1351

take_down_interface = false;

1376

1352

perror("ioctl SIOCSIFFLAGS");

1377

exitcode = EXIT_FAILURE;

1353

exitcode = EX_OSERR;

1378

1354

#ifdef __linux__

1379

1355

if(restore_loglevel){

1380

1356

ret = klogctl(7, NULL, 0);

1446

1422

ret = init_gnutls_global(pubkey, seckey);

1447

1423

if(ret == -1){

1448

1424

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

1449

exitcode = EXIT_FAILURE;

1425

exitcode = EX_UNAVAILABLE;

1450

1426

goto end;

1451

1427

} else {

1452

1428

gnutls_initialized = true;

1469

1445

1470

1446

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

1471

1447

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

1472

exitcode = EXIT_FAILURE;

1448

exitcode = EX_UNAVAILABLE;

1473

1449

goto end;

1474

1450

} else {

1475

1451

gpgme_initialized = true;

1485

1461

char *address = strrchr(connect_to, ':');

1486

1462

if(address == NULL){

1487

1463

fprintf(stderr, "No colon in address\n");

1488

exitcode = EXIT_FAILURE;

1464

exitcode = EX_USAGE;

1489

1465

goto end;

1490

1466

}

1491

1467

1499

1475

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

1500

1476

or tmpmax != (uint16_t)tmpmax){

1501

1477

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

1502

exitcode = EXIT_FAILURE;

1478

exitcode = EX_USAGE;

1503

1479

goto end;

1504

1480

}

1505

1481

1524

1500

1525

1501

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

1526

1502

if(ret < 0){

1527

exitcode = EXIT_FAILURE;

1503

switch(errno){

1504

case ENETUNREACH:

1505

case EHOSTDOWN:

1506

case EHOSTUNREACH:

1507

exitcode = EX_NOHOST;

1508

break;

1509

case EINVAL:

1510

exitcode = EX_USAGE;

1511

break;

1512

case EIO:

1513

exitcode = EX_IOERR;

1514

break;

1515

case EPROTO:

1516

exitcode = EX_PROTOCOL;

1517

break;

1518

default:

1519

exitcode = EX_OSERR;

1520

break;

1521

}

1528

1522

} else {

1529

1523

exitcode = EXIT_SUCCESS;

1530

1524

}

1557

1551

if(mc.server == NULL){

1558

1552

fprintf(stderr, "Failed to create Avahi server: %s\n",

1559

1553

avahi_strerror(error));

1560

exitcode = EXIT_FAILURE;

1554

exitcode = EX_UNAVAILABLE;

1561

1555

goto end;

1562

1556

}

1563

1557

1572

1566

if(sb == NULL){

1573

1567

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

1574

1568

avahi_strerror(avahi_server_errno(mc.server)));

1575

exitcode = EXIT_FAILURE;

1569

exitcode = EX_UNAVAILABLE;

1576

1570

goto end;

1577

1571

}

1578

1572

1627

1621

if(ret == -1){

1628

1622

perror("ioctl SIOCGIFFLAGS");

1629

1623

} else if(network.ifr_flags & IFF_UP) {

1630

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

1624

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

1631

1625

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

1632

1626

if(ret == -1){

1633

1627

perror("ioctl SIOCSIFFLAGS");