/mandos/trunk : revision 367

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() */

47

srand(), strtof() */

48

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

49

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

50

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

72

*/

73

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

74

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

75

setgid(), pause() */

75

setgid() */

76

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

77

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

78

#include <argp.h> /* struct argp_option, error_t, struct

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

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

86

85

87

86

#ifdef __linux__

88

87

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

143

142

.dh_bits = 1024, .priority = "SECURE256"

144

143

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

145

144

146

sig_atomic_t quit_now = 0;

147

int signal_received = 0;

148

149

145

/*

150

146

* Make additional room in "buffer" for at least BUFFER_SIZE more

151

147

* bytes. "buffer_capacity" is how much is currently allocated,

478

474

static int init_gnutls_session(gnutls_session_t *session){

479

475

int ret;

480

476

/* GnuTLS session creation */

481

do {

482

ret = gnutls_init(session, GNUTLS_SERVER);

483

if(quit_now){

484

return -1;

485

}

486

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

477

ret = gnutls_init(session, GNUTLS_SERVER);

487

478

if(ret != GNUTLS_E_SUCCESS){

488

479

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

489

480

safer_gnutls_strerror(ret));

491

482

492

483

{

493

484

const char *err;

494

do {

495

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

496

if(quit_now){

497

gnutls_deinit(*session);

498

return -1;

499

}

500

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

485

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

501

486

if(ret != GNUTLS_E_SUCCESS){

502

487

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

503

488

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

507

492

}

508

493

}

509

494

510

do {

511

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

512

mc.cred);

513

if(quit_now){

514

gnutls_deinit(*session);

515

return -1;

516

}

517

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

495

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

496

mc.cred);

518

497

if(ret != GNUTLS_E_SUCCESS){

519

498

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

520

499

safer_gnutls_strerror(ret));

523

502

}

524

503

525

504

/* ignore client certificate if any. */

526

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

505

gnutls_certificate_server_set_request(*session,

506

GNUTLS_CERT_IGNORE);

527

507

528

508

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

529

509

534

514

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

535

515

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

536

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

537

520

/* Called when a Mandos server is found */

538

521

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

539

522

AvahiIfIndex if_index,

545

528

struct sockaddr_in6 in6;

546

529

} to;

547

530

char *buffer = NULL;

548

char *decrypted_buffer = NULL;

531

char *decrypted_buffer;

549

532

size_t buffer_length = 0;

550

533

size_t buffer_capacity = 0;

551

534

size_t written;

552

int retval = -1;

535

int retval = 0;

553

536

gnutls_session_t session;

554

537

int pf; /* Protocol family */

555

538

582

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

583

566

if(tcp_sd < 0){

584

567

perror("socket");

568

retval = -1;

585

569

goto mandos_end;

586

570

}

587

571

599

583

}

600

584

if(ret < 0 ){

601

585

perror("inet_pton");

586

retval = -1;

602

587

goto mandos_end;

603

588

}

604

589

if(ret == 0){

605

590

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

591

retval = -1;

606

592

goto mandos_end;

607

593

}

608

594

if(af == AF_INET6){

616

602

if(if_index == AVAHI_IF_UNSPEC){

617

603

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

618

604

" without a network interface\n");

605

retval = -1;

619

606

goto mandos_end;

620

607

}

621

608

/* Set the network interface number as scope */

674

661

}

675

662

if(ret < 0){

676

663

perror("connect");

664

retval = -1;

677

665

goto mandos_end;

678

666

}

679

667

689

677

out_size - written));

690

678

if(ret == -1){

691

679

perror("write");

680

retval = -1;

692

681

goto mandos_end;

693

682

}

694

683

written += (size_t)ret;

734

723

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

735

724

gnutls_perror(ret);

736

725

}

726

retval = -1;

737

727

goto mandos_end;

738

728

}

739

729

754

744

buffer_capacity);

755

745

if(buffer_capacity == 0){

756

746

perror("incbuffer");

747

retval = -1;

757

748

goto mandos_end;

758

749

}

759

750

782

773

if(ret < 0){

783

774

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

784

775

gnutls_perror(ret);

776

retval = -1;

785

777

goto mandos_end;

786

778

}

787

779

break;

788

780

default:

789

781

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

790

782

" encrypted session with Mandos server\n");

783

retval = -1;

791

784

gnutls_bye(session, GNUTLS_SHUT_RDWR);

792

785

goto mandos_end;

793

786

}

804

797

goto mandos_end;

805

798

}

806

799

807

do {

808

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

809

if(quit_now){

810

goto mandos_end;

811

}

812

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

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

802

if(quit_now){

803

goto mandos_end;

804

}

813

805

814

806

if(buffer_length > 0){

815

807

ssize_t decrypted_buffer_size;

832

824

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

833

825

strerror(errno));

834

826

}

835

goto mandos_end;

827

retval = -1;

828

break;

836

829

}

837

830

written += (size_t)ret;

838

831

}

839

retval = 0;

832

free(decrypted_buffer);

833

} else {

834

retval = -1;

840

835

}

836

} else {

837

retval = -1;

841

838

}

842

839

843

840

/* Shutdown procedure */

844

841

845

842

mandos_end:

846

free(decrypted_buffer);

847

843

free(buffer);

848

844

if(tcp_sd >= 0){

849

845

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

999

995

bool gpgme_initialized = false;

1000

996

float delay = 2.5f;

1001

997

1002

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

998

struct sigaction old_sigterm_action;

1003

999

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1004

1000

1005

uid = getuid();

1006

gid = getgid();

1007

1008

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

1009

errno = 0;

1010

ret = setgid(gid);

1011

if(ret == -1){

1012

perror("setgid");

1013

}

1014

1015

/* Lower user privileges (temporarily) */

1016

errno = 0;

1017

ret = seteuid(uid);

1018

if(ret == -1){

1019

perror("seteuid");

1020

}

1021

1022

if(quit_now){

1023

goto end;

1024

}

1025

1026

1001

{

1027

1002

struct argp_option options[] = {

1028

1003

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

1057

1032

.arg = "SECONDS",

1058

1033

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

1059

1034

.group = 2 },

1060

/*

1061

* These reproduce what we would get without ARGP_NO_HELP

1062

*/

1063

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

1064

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

1065

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

1066

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

1067

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

1068

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

1069

1035

{ .name = NULL }

1070

1036

};

1071

1037

1072

1038

error_t parse_opt(int key, char *arg,

1073

1039

struct argp_state *state){

1074

errno = 0;

1075

1040

switch(key){

1076

1041

case 128: /* --debug */

1077

1042

debug = true;

1093

1058

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

1094

1059

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

1095

1060

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

1096

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

1061

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

1062

exit(EXIT_FAILURE);

1097

1063

}

1098

1064

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

1099

1065

break;

1104

1070

errno = 0;

1105

1071

delay = strtof(arg, &tmp);

1106

1072

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

1107

argp_error(state, "Bad delay");

1073

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

1074

exit(EXIT_FAILURE);

1108

1075

}

1109

1076

break;

1110

/*

1111

* These reproduce what we would get without ARGP_NO_HELP

1112

*/

1113

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

1114

argp_state_help(state, state->out_stream,

1115

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1116

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1117

case -3: /* --usage */

1118

argp_state_help(state, state->out_stream,

1119

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1120

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

1121

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

1122

exit(argp_err_exit_status);

1077

case ARGP_KEY_ARG:

1078

argp_usage(state);

1079

case ARGP_KEY_END:

1123

1080

break;

1124

1081

default:

1125

1082

return ARGP_ERR_UNKNOWN;

1126

1083

}

1127

return errno;

1084

return 0;

1128

1085

}

1129

1086

1130

1087

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

1131

1088

.args_doc = "",

1132

1089

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

1133

1090

" passwords from a Mandos server" };

1134

ret = argp_parse(&argp, argc, argv,

1135

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1136

switch(ret){

1137

case 0:

1138

break;

1139

case ENOMEM:

1140

default:

1141

errno = ret;

1142

perror("argp_parse");

1143

exitcode = EX_OSERR;

1144

goto end;

1145

case EINVAL:

1146

exitcode = EX_USAGE;

1091

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

1092

if(ret == ARGP_ERR_UNKNOWN){

1093

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

1094

exitcode = EXIT_FAILURE;

1147

1095

goto end;

1148

1096

}

1149

1097

}

1239

1187

goto end;

1240

1188

}

1241

1189

1242

/* Re-raise priviliges */

1243

errno = 0;

1244

ret = seteuid(0);

1245

if(ret == -1){

1246

perror("seteuid");

1247

}

1248

1249

1190

#ifdef __linux__

1250

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1251

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

1192

messages to mess up the prompt */

1252

1193

ret = klogctl(8, NULL, 5);

1253

1194

bool restore_loglevel = true;

1254

1195

if(ret == -1){

1269

1210

}

1270

1211

}

1271

1212

#endif /* __linux__ */

1272

/* Lower privileges */

1273

errno = 0;

1274

ret = seteuid(uid);

1275

if(ret == -1){

1276

perror("seteuid");

1277

}

1278

1213

goto end;

1279

1214

}

1280

1215

strcpy(network.ifr_name, interface);

1290

1225

}

1291

1226

#endif /* __linux__ */

1292

1227

exitcode = EXIT_FAILURE;

1293

/* Lower privileges */

1294

errno = 0;

1295

ret = seteuid(uid);

1296

if(ret == -1){

1297

perror("seteuid");

1298

}

1299

1228

goto end;

1300

1229

}

1301

1230

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

1314

1243

}

1315

1244

}

1316

1245

#endif /* __linux__ */

1317

/* Lower privileges */

1318

errno = 0;

1319

ret = seteuid(uid);

1320

if(ret == -1){

1321

perror("seteuid");

1322

}

1323

1246

goto end;

1324

1247

}

1325

1248

}

1353

1276

}

1354

1277

}

1355

1278

#endif /* __linux__ */

1356

/* Lower privileges */

1357

errno = 0;

1358

if(take_down_interface){

1359

/* Lower privileges */

1360

ret = seteuid(uid);

1361

if(ret == -1){

1362

perror("seteuid");

1363

}

1364

} else {

1365

/* Lower privileges permanently */

1366

ret = setuid(uid);

1367

if(ret == -1){

1368

perror("setuid");

1369

}

1279

}

1280

1281

if(quit_now){

1282

goto end;

1283

}

1284

1285

uid = getuid();

1286

gid = getgid();

1287

1288

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

1289

errno = 0;

1290

ret = setgid(gid);

1291

if(ret == -1){

1292

perror("setgid");

1293

}

1294

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");

1370

1309

}

1371

1310

}

1372

1311

1558

1497

if(ret == -1){

1559

1498

perror("ioctl SIOCGIFFLAGS");

1560

1499

} else if(network.ifr_flags & IFF_UP) {

1561

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

1500

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

1562

1501

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

1563

1502

if(ret == -1){

1564

1503

perror("ioctl SIOCSIFFLAGS");

1568

1507

if(ret == -1){

1569

1508

perror("close");

1570

1509

}

1571

/* Lower privileges permanently */

1510

/* Lower privileges, permanently this time */

1572

1511

errno = 0;

1573

1512

ret = setuid(uid);

1574

1513

if(ret == -1){

1624

1563

if(quit_now){

1625

1564

sigemptyset(&old_sigterm_action.sa_mask);

1626

1565

old_sigterm_action.sa_handler = SIG_DFL;

1627

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1628

&old_sigterm_action,

1629

NULL));

1566

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

1630

1567

if(ret == -1){

1631

1568

perror("sigaction");

1632

1569

}

1633

do {

1634

ret = raise(signal_received);

1635

} while(ret != 0 and errno == EINTR);

1636

if(ret != 0){

1637

perror("raise");

1638

abort();

1639

}

1640

TEMP_FAILURE_RETRY(pause());

1570

raise(signal_received);

1641

1571

}

1642

1572

1643

1573

return exitcode;