/mandos/trunk : revision 348

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

38

42

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

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

42

45

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

43

46

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

44

srand() */

47

srand(), strtof() */

45

48

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

46

49

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

47

50

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

56

59

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

57

60

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

58

61

*/

59

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

62

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

63

strtoimax() */

60

64

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

61

65

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

62

66

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

75

79

argp_state, struct argp,

76

80

argp_parse(), ARGP_KEY_ARG,

77

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sigaction,

84

sig_atomic_t */

85

78

86

#ifdef __linux__

79

87

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

80

#endif

88

#endif /* __linux__ */

81

89

82

90

/* Avahi */

83

91

/* All Avahi types, constants and functions

129

137

gpgme_ctx_t ctx;

130

138

} mandos_context;

131

139

140

/* global context so signal handler can reach it*/

141

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

142

.dh_bits = 1024, .priority = "SECURE256"

143

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

144

132

145

/*

133

* Make room in "buffer" for at least BUFFER_SIZE additional bytes.

134

* "buffer_capacity" is how much is currently allocated,

146

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

147

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

135

148

* "buffer_length" is how much is already used.

136

149

*/

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

150

size_t incbuffer(char **buffer, size_t buffer_length,

138

151

size_t buffer_capacity){

139

152

if(buffer_length + BUFFER_SIZE > buffer_capacity){

140

153

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

149

162

/*

150

163

* Initialize GPGME.

151

164

*/

152

static bool init_gpgme(mandos_context *mc, const char *seckey,

165

static bool init_gpgme(const char *seckey,

153

166

const char *pubkey, const char *tempdir){

154

167

int ret;

155

168

gpgme_error_t rc;

176

189

return false;

177

190

}

178

191

179

rc = gpgme_op_import(mc->ctx, pgp_data);

192

rc = gpgme_op_import(mc.ctx, pgp_data);

180

193

if(rc != GPG_ERR_NO_ERROR){

181

194

fprintf(stderr, "bad gpgme_op_import: %s: %s\n",

182

195

gpgme_strsource(rc), gpgme_strerror(rc));

192

205

}

193

206

194

207

if(debug){

195

fprintf(stderr, "Initialize gpgme\n");

208

fprintf(stderr, "Initializing GPGME\n");

196

209

}

197

210

198

211

/* Init GPGME */

225

238

}

226

239

227

240

/* Create new GPGME "context" */

228

rc = gpgme_new(&(mc->ctx));

241

rc = gpgme_new(&(mc.ctx));

229

242

if(rc != GPG_ERR_NO_ERROR){

230

243

fprintf(stderr, "bad gpgme_new: %s: %s\n",

231

244

gpgme_strsource(rc), gpgme_strerror(rc));

243

256

* Decrypt OpenPGP data.

244

257

* Returns -1 on error

245

258

*/

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

259

static ssize_t pgp_packet_decrypt(const char *cryptotext,

248

260

size_t crypto_size,

249

261

char **plaintext){

250

262

gpgme_data_t dh_crypto, dh_plain;

277

289

278

290

/* Decrypt data from the cryptotext data buffer to the plaintext

279

291

data buffer */

280

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

292

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

281

293

if(rc != GPG_ERR_NO_ERROR){

282

294

fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",

283

295

gpgme_strsource(rc), gpgme_strerror(rc));

284

296

plaintext_length = -1;

285

297

if(debug){

286

298

gpgme_decrypt_result_t result;

287

result = gpgme_op_decrypt_result(mc->ctx);

299

result = gpgme_op_decrypt_result(mc.ctx);

288

300

if(result == NULL){

289

301

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

290

302

} else {

326

338

327

339

*plaintext = NULL;

328

340

while(true){

329

plaintext_capacity = adjustbuffer(plaintext,

341

plaintext_capacity = incbuffer(plaintext,

330

342

(size_t)plaintext_length,

331

343

plaintext_capacity);

332

344

if(plaintext_capacity == 0){

333

perror("adjustbuffer");

345

perror("incbuffer");

334

346

plaintext_length = -1;

335

347

goto decrypt_end;

336

348

}

382

394

fprintf(stderr, "GnuTLS: %s", string);

383

395

}

384

396

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

397

static int init_gnutls_global(const char *pubkeyfilename,

387

398

const char *seckeyfilename){

388

399

int ret;

389

400

407

418

}

408

419

409

420

/* OpenPGP credentials */

410

gnutls_certificate_allocate_credentials(&mc->cred);

421

gnutls_certificate_allocate_credentials(&mc.cred);

411

422

if(ret != GNUTLS_E_SUCCESS){

412

423

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

413

424

from

425

436

}

426

437

427

438

ret = gnutls_certificate_set_openpgp_key_file

428

(mc->cred, pubkeyfilename, seckeyfilename,

439

(mc.cred, pubkeyfilename, seckeyfilename,

429

440

GNUTLS_OPENPGP_FMT_BASE64);

430

441

if(ret != GNUTLS_E_SUCCESS){

431

442

fprintf(stderr,

437

448

}

438

449

439

450

/* GnuTLS server initialization */

440

ret = gnutls_dh_params_init(&mc->dh_params);

451

ret = gnutls_dh_params_init(&mc.dh_params);

441

452

if(ret != GNUTLS_E_SUCCESS){

442

453

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

443

454

" %s\n", safer_gnutls_strerror(ret));

444

455

goto globalfail;

445

456

}

446

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

457

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

447

458

if(ret != GNUTLS_E_SUCCESS){

448

459

fprintf(stderr, "Error in GnuTLS prime generation: %s\n",

449

460

safer_gnutls_strerror(ret));

450

461

goto globalfail;

451

462

}

452

463

453

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

464

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

454

465

455

466

return 0;

456

467

457

468

globalfail:

458

469

459

gnutls_certificate_free_credentials(mc->cred);

470

gnutls_certificate_free_credentials(mc.cred);

460

471

gnutls_global_deinit();

461

gnutls_dh_params_deinit(mc->dh_params);

472

gnutls_dh_params_deinit(mc.dh_params);

462

473

return -1;

463

474

}

464

475

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

476

static int init_gnutls_session(gnutls_session_t *session){

467

477

int ret;

468

478

/* GnuTLS session creation */

469

479

ret = gnutls_init(session, GNUTLS_SERVER);

474

484

475

485

{

476

486

const char *err;

477

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

487

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

478

488

if(ret != GNUTLS_E_SUCCESS){

479

489

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

480

490

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

485

495

}

486

496

487

497

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

488

mc->cred);

498

mc.cred);

489

499

if(ret != GNUTLS_E_SUCCESS){

490

500

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

491

501

safer_gnutls_strerror(ret));

497

507

gnutls_certificate_server_set_request(*session,

498

508

GNUTLS_CERT_IGNORE);

499

509

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

510

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

501

511

502

512

return 0;

503

513

}

509

519

/* Called when a Mandos server is found */

510

520

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

511

521

AvahiIfIndex if_index,

512

mandos_context *mc, int af){

522

int af){

513

523

int ret, tcp_sd;

514

524

ssize_t sret;

515

525

union {

538

548

return -1;

539

549

}

540

550

541

ret = init_gnutls_session(mc, &session);

551

ret = init_gnutls_session(&session);

542

552

if(ret != 0){

543

553

return -1;

544

554

}

556

566

557

567

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

558

568

if(af == AF_INET6){

559

to.in6.sin6_family = (uint16_t)af;

569

to.in6.sin6_family = (sa_family_t)af;

560

570

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

561

571

} else { /* IPv4 */

562

572

to.in.sin_family = (sa_family_t)af;

685

695

}

686

696

687

697

while(true){

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

698

buffer_capacity = incbuffer(&buffer, buffer_length,

689

699

buffer_capacity);

690

700

if(buffer_capacity == 0){

691

perror("adjustbuffer");

701

perror("incbuffer");

692

702

retval = -1;

693

703

goto mandos_end;

694

704

}

733

743

gnutls_bye(session, GNUTLS_SHUT_RDWR);

734

744

735

745

if(buffer_length > 0){

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

746

decrypted_buffer_size = pgp_packet_decrypt(buffer,

737

747

buffer_length,

738

748

&decrypted_buffer);

739

749

if(decrypted_buffer_size >= 0){

785

795

AVAHI_GCC_UNUSED AvahiStringList *txt,

786

796

AVAHI_GCC_UNUSED AvahiLookupResultFlags

787

797

flags,

788

void* userdata){

789

mandos_context *mc = userdata;

798

AVAHI_GCC_UNUSED void* userdata){

790

799

assert(r);

791

800

792

801

/* Called whenever a service has been resolved successfully or

797

806

case AVAHI_RESOLVER_FAILURE:

798

807

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

799

808

" of type '%s' in domain '%s': %s\n", name, type, domain,

800

avahi_strerror(avahi_server_errno(mc->server)));

809

avahi_strerror(avahi_server_errno(mc.server)));

801

810

break;

802

811

803

812

case AVAHI_RESOLVER_FOUND:

809

818

PRIdMAX ") on port %" PRIu16 "\n", name, host_name,

810

819

ip, (intmax_t)interface, port);

811

820

}

812

int ret = start_mandos_communication(ip, port, interface, mc,

821

int ret = start_mandos_communication(ip, port, interface,

813

822

avahi_proto_to_af(proto));

814

823

if(ret == 0){

815

avahi_simple_poll_quit(mc->simple_poll);

824

avahi_simple_poll_quit(mc.simple_poll);

816

825

}

817

826

}

818

827

}

828

837

const char *domain,

829

838

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

839

flags,

831

void* userdata){

832

mandos_context *mc = userdata;

840

AVAHI_GCC_UNUSED void* userdata){

833

841

assert(b);

834

842

835

843

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

840

848

case AVAHI_BROWSER_FAILURE:

841

849

842

850

fprintf(stderr, "(Avahi browser) %s\n",

843

avahi_strerror(avahi_server_errno(mc->server)));

844

avahi_simple_poll_quit(mc->simple_poll);

851

avahi_strerror(avahi_server_errno(mc.server)));

852

avahi_simple_poll_quit(mc.simple_poll);

845

853

return;

846

854

847

855

case AVAHI_BROWSER_NEW:

850

858

the callback function is called the Avahi server will free the

851

859

resolver for us. */

852

860

853

if(!(avahi_s_service_resolver_new(mc->server, interface,

854

protocol, name, type, domain,

855

AVAHI_PROTO_INET6, 0,

856

resolve_callback, mc)))

861

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

862

name, type, domain, protocol, 0,

863

resolve_callback, NULL) == NULL)

857

864

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

858

name, avahi_strerror(avahi_server_errno(mc->server)));

865

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

859

866

break;

860

867

861

868

case AVAHI_BROWSER_REMOVE:

870

877

}

871

878

}

872

879

880

sig_atomic_t quit_now = 0;

881

882

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

883

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

884

if(quit_now){

885

return;

886

}

887

quit_now = 1;

888

int old_errno = errno;

889

if(mc.simple_poll != NULL){

890

avahi_simple_poll_quit(mc.simple_poll);

891

}

892

errno = old_errno;

893

}

894

873

895

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

874

896

AvahiSServiceBrowser *sb = NULL;

875

897

int error;

876

898

int ret;

877

899

intmax_t tmpmax;

878

int numchars;

900

char *tmp;

879

901

int exitcode = EXIT_SUCCESS;

880

902

const char *interface = "eth0";

881

903

struct ifreq network;

889

911

const char *seckey = PATHDIR "/" SECKEY;

890

912

const char *pubkey = PATHDIR "/" PUBKEY;

891

913

892

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

893

.dh_bits = 1024, .priority = "SECURE256"

894

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

895

914

bool gnutls_initialized = false;

896

915

bool gpgme_initialized = false;

897

double delay = 2.5;

916

float delay = 2.5f;

917

918

struct sigaction old_sigterm_action;

919

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

898

920

899

921

{

900

922

struct argp_option options[] = {

952

974

pubkey = arg;

953

975

break;

954

976

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

955

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

956

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

957

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

977

errno = 0;

978

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

979

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

980

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

958

981

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

959

982

exit(EXIT_FAILURE);

960

983

}

964

987

mc.priority = arg;

965

988

break;

966

989

case 131: /* --delay */

967

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

968

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

990

errno = 0;

991

delay = strtof(arg, &tmp);

992

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

969

993

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

970

994

exit(EXIT_FAILURE);

971

995

}

992

1016

}

993

1017

}

994

1018

1019

if(not debug){

1020

avahi_set_log_function(empty_log);

1021

}

1022

1023

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

1024

from the signal handler */

1025

/* Initialize the pseudo-RNG for Avahi */

1026

srand((unsigned int) time(NULL));

1027

mc.simple_poll = avahi_simple_poll_new();

1028

if(mc.simple_poll == NULL){

1029

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

1030

exitcode = EXIT_FAILURE;

1031

goto end;

1032

}

1033

1034

sigemptyset(&sigterm_action.sa_mask);

1035

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

1036

if(ret == -1){

1037

perror("sigaddset");

1038

exitcode = EXIT_FAILURE;

1039

goto end;

1040

}

1041

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

1042

if(ret == -1){

1043

perror("sigaddset");

1044

exitcode = EXIT_FAILURE;

1045

goto end;

1046

}

1047

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

1048

if(ret == -1){

1049

perror("sigaddset");

1050

exitcode = EXIT_FAILURE;

1051

goto end;

1052

}

1053

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

1054

if(ret == -1){

1055

perror("sigaction");

1056

exitcode = EXIT_FAILURE;

1057

goto end;

1058

}

1059

995

1060

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

996

1061

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

997

1062

#ifdef __linux__

1003

1068

restore_loglevel = false;

1004

1069

perror("klogctl");

1005

1070

}

1006

#endif

1071

#endif /* __linux__ */

1007

1072

1008

1073

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1009

1074

if(sd < 0){

1016

1081

perror("klogctl");

1017

1082

}

1018

1083

}

1019

#endif

1084

#endif /* __linux__ */

1020

1085

goto end;

1021

1086

}

1022

1087

strcpy(network.ifr_name, interface);

1030

1095

perror("klogctl");

1031

1096

}

1032

1097

}

1033

#endif

1098

#endif /* __linux__ */

1034

1099

exitcode = EXIT_FAILURE;

1035

1100

goto end;

1036

1101

}

1047

1112

perror("klogctl");

1048

1113

}

1049

1114

}

1050

#endif

1115

#endif /* __linux__ */

1051

1116

goto end;

1052

1117

}

1053

1118

}

1077

1142

perror("klogctl");

1078

1143

}

1079

1144

}

1080

#endif

1145

#endif /* __linux__ */

1081

1146

}

1082

1147

1083

1148

uid = getuid();

1094

1159

perror("setuid");

1095

1160

}

1096

1161

1097

ret = init_gnutls_global(&mc, pubkey, seckey);

1162

ret = init_gnutls_global(pubkey, seckey);

1098

1163

if(ret == -1){

1099

1164

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

1100

1165

exitcode = EXIT_FAILURE;

1109

1174

}

1110

1175

tempdir_created = true;

1111

1176

1112

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

1177

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

1113

1178

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

1114

1179

exitcode = EXIT_FAILURE;

1115

1180

goto end;

1136

1201

goto end;

1137

1202

}

1138

1203

uint16_t port;

1139

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

1140

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

1141

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

1204

errno = 0;

1205

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

1206

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

1207

or tmpmax != (uint16_t)tmpmax){

1142

1208

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

1143

1209

exitcode = EXIT_FAILURE;

1144

1210

goto end;

1153

1219

} else {

1154

1220

af = AF_INET;

1155

1221

}

1156

ret = start_mandos_communication(address, port, if_index, &mc,

1157

af);

1222

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

1158

1223

if(ret < 0){

1159

1224

exitcode = EXIT_FAILURE;

1160

1225

} else {

1162

1227

}

1163

1228

goto end;

1164

1229

}

1165

1166

if(not debug){

1167

avahi_set_log_function(empty_log);

1168

}

1169

1170

/* Initialize the pseudo-RNG for Avahi */

1171

srand((unsigned int) time(NULL));

1172

1173

/* Allocate main Avahi loop object */

1174

mc.simple_poll = avahi_simple_poll_new();

1175

if(mc.simple_poll == NULL){

1176

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

1177

exitcode = EXIT_FAILURE;

1178

goto end;

1179

}

1180

1230

1181

1231

{

1182

1232

AvahiServerConfig config;

1183

1233

/* Do not publish any local Zeroconf records */

1206

1256

1207

1257

/* Create the Avahi service browser */

1208

1258

sb = avahi_s_service_browser_new(mc.server, if_index,

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1210

NULL, 0, browse_callback, &mc);

1259

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1260

NULL, 0, browse_callback, NULL);

1211

1261

if(sb == NULL){

1212

1262

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

1213

1263

avahi_strerror(avahi_server_errno(mc.server)));