/mandos/trunk : revision 305

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() */

79

75

argp_state, struct argp,

80

76

argp_parse(), ARGP_KEY_ARG,

81

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sigaction,

84

sig_atomic_t */

85

86

78

#ifdef __linux__

87

79

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

88

#endif /* __linux__ */

80

#endif

89

81

90

82

/* Avahi */

91

83

/* All Avahi types, constants and functions

137

129

gpgme_ctx_t ctx;

138

130

} mandos_context;

139

131

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

145

132

/*

146

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

147

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

133

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

134

* "buffer_capacity" is how much is currently allocated,

148

135

* "buffer_length" is how much is already used.

149

136

*/

150

size_t incbuffer(char **buffer, size_t buffer_length,

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

151

138

size_t buffer_capacity){

152

139

if(buffer_length + BUFFER_SIZE > buffer_capacity){

153

140

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

162

149

/*

163

150

* Initialize GPGME.

164

151

*/

165

static bool init_gpgme(const char *seckey,

152

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

166

153

const char *pubkey, const char *tempdir){

167

154

int ret;

168

155

gpgme_error_t rc;

189

176

return false;

190

177

}

191

178

192

rc = gpgme_op_import(mc.ctx, pgp_data);

179

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

193

180

if(rc != GPG_ERR_NO_ERROR){

194

181

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

195

182

gpgme_strsource(rc), gpgme_strerror(rc));

205

192

}

206

193

207

194

if(debug){

208

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

195

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

209

196

}

210

197

211

198

/* Init GPGME */

238

225

}

239

226

240

227

/* Create new GPGME "context" */

241

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

228

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

242

229

if(rc != GPG_ERR_NO_ERROR){

243

230

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

244

231

gpgme_strsource(rc), gpgme_strerror(rc));

256

243

* Decrypt OpenPGP data.

257

244

* Returns -1 on error

258

245

*/

259

static ssize_t pgp_packet_decrypt(const char *cryptotext,

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

260

248

size_t crypto_size,

261

249

char **plaintext){

262

250

gpgme_data_t dh_crypto, dh_plain;

289

277

290

278

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

291

279

data buffer */

292

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

280

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

293

281

if(rc != GPG_ERR_NO_ERROR){

294

282

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

295

283

gpgme_strsource(rc), gpgme_strerror(rc));

296

284

plaintext_length = -1;

297

285

if(debug){

298

286

gpgme_decrypt_result_t result;

299

result = gpgme_op_decrypt_result(mc.ctx);

287

result = gpgme_op_decrypt_result(mc->ctx);

300

288

if(result == NULL){

301

289

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

302

290

} else {

338

326

339

327

*plaintext = NULL;

340

328

while(true){

341

plaintext_capacity = incbuffer(plaintext,

329

plaintext_capacity = adjustbuffer(plaintext,

342

330

(size_t)plaintext_length,

343

331

plaintext_capacity);

344

332

if(plaintext_capacity == 0){

345

perror("incbuffer");

333

perror("adjustbuffer");

346

334

plaintext_length = -1;

347

335

goto decrypt_end;

348

336

}

394

382

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

395

383

}

396

384

397

static int init_gnutls_global(const char *pubkeyfilename,

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

398

387

const char *seckeyfilename){

399

388

int ret;

400

389

418

407

}

419

408

420

409

/* OpenPGP credentials */

421

gnutls_certificate_allocate_credentials(&mc.cred);

410

gnutls_certificate_allocate_credentials(&mc->cred);

422

411

if(ret != GNUTLS_E_SUCCESS){

423

412

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

424

413

from

436

425

}

437

426

438

427

ret = gnutls_certificate_set_openpgp_key_file

439

(mc.cred, pubkeyfilename, seckeyfilename,

428

(mc->cred, pubkeyfilename, seckeyfilename,

440

429

GNUTLS_OPENPGP_FMT_BASE64);

441

430

if(ret != GNUTLS_E_SUCCESS){

442

431

fprintf(stderr,

448

437

}

449

438

450

439

/* GnuTLS server initialization */

451

ret = gnutls_dh_params_init(&mc.dh_params);

440

ret = gnutls_dh_params_init(&mc->dh_params);

452

441

if(ret != GNUTLS_E_SUCCESS){

453

442

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

454

443

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

455

444

goto globalfail;

456

445

}

457

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

446

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

458

447

if(ret != GNUTLS_E_SUCCESS){

459

448

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

460

449

safer_gnutls_strerror(ret));

461

450

goto globalfail;

462

451

}

463

452

464

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

453

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

465

454

466

455

return 0;

467

456

468

457

globalfail:

469

458

470

gnutls_certificate_free_credentials(mc.cred);

459

gnutls_certificate_free_credentials(mc->cred);

471

460

gnutls_global_deinit();

472

gnutls_dh_params_deinit(mc.dh_params);

461

gnutls_dh_params_deinit(mc->dh_params);

473

462

return -1;

474

463

}

475

464

476

static int init_gnutls_session(gnutls_session_t *session){

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

477

467

int ret;

478

468

/* GnuTLS session creation */

479

469

ret = gnutls_init(session, GNUTLS_SERVER);

484

474

485

475

{

486

476

const char *err;

487

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

477

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

488

478

if(ret != GNUTLS_E_SUCCESS){

489

479

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

490

480

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

495

485

}

496

486

497

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

498

mc.cred);

488

mc->cred);

499

489

if(ret != GNUTLS_E_SUCCESS){

500

490

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

501

491

safer_gnutls_strerror(ret));

507

497

gnutls_certificate_server_set_request(*session,

508

498

GNUTLS_CERT_IGNORE);

509

499

510

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

511

501

512

502

return 0;

513

503

}

519

509

/* Called when a Mandos server is found */

520

510

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

521

511

AvahiIfIndex if_index,

522

int af){

512

mandos_context *mc, int af){

523

513

int ret, tcp_sd;

524

514

ssize_t sret;

525

515

union {

548

538

return -1;

549

539

}

550

540

551

ret = init_gnutls_session(&session);

541

ret = init_gnutls_session(mc, &session);

552

542

if(ret != 0){

553

543

return -1;

554

544

}

695

685

}

696

686

697

687

while(true){

698

buffer_capacity = incbuffer(&buffer, buffer_length,

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

699

689

buffer_capacity);

700

690

if(buffer_capacity == 0){

701

perror("incbuffer");

691

perror("adjustbuffer");

702

692

retval = -1;

703

693

goto mandos_end;

704

694

}

743

733

gnutls_bye(session, GNUTLS_SHUT_RDWR);

744

734

745

735

if(buffer_length > 0){

746

decrypted_buffer_size = pgp_packet_decrypt(buffer,

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

747

737

buffer_length,

748

738

&decrypted_buffer);

749

739

if(decrypted_buffer_size >= 0){

795

785

AVAHI_GCC_UNUSED AvahiStringList *txt,

796

786

AVAHI_GCC_UNUSED AvahiLookupResultFlags

797

787

flags,

798

AVAHI_GCC_UNUSED void* userdata){

788

void* userdata){

789

mandos_context *mc = userdata;

799

790

assert(r);

800

791

801

792

/* Called whenever a service has been resolved successfully or

806

797

case AVAHI_RESOLVER_FAILURE:

807

798

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

808

799

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

809

avahi_strerror(avahi_server_errno(mc.server)));

800

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

810

801

break;

811

802

812

803

case AVAHI_RESOLVER_FOUND:

818

809

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

819

810

ip, (intmax_t)interface, port);

820

811

}

821

int ret = start_mandos_communication(ip, port, interface,

812

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

822

813

avahi_proto_to_af(proto));

823

814

if(ret == 0){

824

avahi_simple_poll_quit(mc.simple_poll);

815

avahi_simple_poll_quit(mc->simple_poll);

825

816

}

826

817

}

827

818

}

837

828

const char *domain,

838

829

AVAHI_GCC_UNUSED AvahiLookupResultFlags

839

830

flags,

840

AVAHI_GCC_UNUSED void* userdata){

831

void* userdata){

832

mandos_context *mc = userdata;

841

833

assert(b);

842

834

843

835

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

848

840

case AVAHI_BROWSER_FAILURE:

849

841

850

842

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

851

avahi_strerror(avahi_server_errno(mc.server)));

852

avahi_simple_poll_quit(mc.simple_poll);

843

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

844

avahi_simple_poll_quit(mc->simple_poll);

853

845

return;

854

846

855

847

case AVAHI_BROWSER_NEW:

858

850

the callback function is called the Avahi server will free the

859

851

resolver for us. */

860

852

861

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

862

name, type, domain, protocol, 0,

863

resolve_callback, NULL) == NULL)

853

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

854

protocol, name, type, domain,

855

AVAHI_PROTO_INET6, 0,

856

resolve_callback, mc)))

864

857

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

865

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

858

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

866

859

break;

867

860

868

861

case AVAHI_BROWSER_REMOVE:

877

870

}

878

871

}

879

872

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

895

873

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

896

874

AvahiSServiceBrowser *sb = NULL;

897

875

int error;

898

876

int ret;

899

877

intmax_t tmpmax;

900

char *tmp;

878

int numchars;

901

879

int exitcode = EXIT_SUCCESS;

902

880

const char *interface = "eth0";

903

881

struct ifreq network;

911

889

const char *seckey = PATHDIR "/" SECKEY;

912

890

const char *pubkey = PATHDIR "/" PUBKEY;

913

891

892

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

893

.dh_bits = 1024, .priority = "SECURE256"

894

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

914

895

bool gnutls_initialized = false;

915

896

bool gpgme_initialized = false;

916

float delay = 2.5f;

917

918

struct sigaction old_sigterm_action;

919

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

897

double delay = 2.5;

920

898

921

899

{

922

900

struct argp_option options[] = {

974

952

pubkey = arg;

975

953

break;

976

954

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

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){

955

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

956

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

957

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

981

958

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

982

959

exit(EXIT_FAILURE);

983

960

}

987

964

mc.priority = arg;

988

965

break;

989

966

case 131: /* --delay */

990

errno = 0;

991

delay = strtof(arg, &tmp);

992

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

967

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

968

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

993

969

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

994

970

exit(EXIT_FAILURE);

995

971

}

1016

992

}

1017

993

}

1018

994

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

1060

995

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

1061

996

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

1062

997

#ifdef __linux__

1068

1003

restore_loglevel = false;

1069

1004

perror("klogctl");

1070

1005

}

1071

#endif /* __linux__ */

1006

#endif

1072

1007

1073

1008

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1074

1009

if(sd < 0){

1081

1016

perror("klogctl");

1082

1017

}

1083

1018

}

1084

#endif /* __linux__ */

1019

#endif

1085

1020

goto end;

1086

1021

}

1087

1022

strcpy(network.ifr_name, interface);

1095

1030

perror("klogctl");

1096

1031

}

1097

1032

}

1098

#endif /* __linux__ */

1033

#endif

1099

1034

exitcode = EXIT_FAILURE;

1100

1035

goto end;

1101

1036

}

1112

1047

perror("klogctl");

1113

1048

}

1114

1049

}

1115

#endif /* __linux__ */

1050

#endif

1116

1051

goto end;

1117

1052

}

1118

1053

}

1142

1077

perror("klogctl");

1143

1078

}

1144

1079

}

1145

#endif /* __linux__ */

1080

#endif

1146

1081

}

1147

1082

1148

1083

uid = getuid();

1159

1094

perror("setuid");

1160

1095

}

1161

1096

1162

ret = init_gnutls_global(pubkey, seckey);

1097

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

1163

1098

if(ret == -1){

1164

1099

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

1165

1100

exitcode = EXIT_FAILURE;

1174

1109

}

1175

1110

tempdir_created = true;

1176

1111

1177

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

1112

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

1178

1113

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

1179

1114

exitcode = EXIT_FAILURE;

1180

1115

goto end;

1201

1136

goto end;

1202

1137

}

1203

1138

uint16_t port;

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){

1139

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

1140

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

1141

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

1208

1142

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

1209

1143

exitcode = EXIT_FAILURE;

1210

1144

goto end;

1219

1153

} else {

1220

1154

af = AF_INET;

1221

1155

}

1222

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

1156

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

1157

af);

1223

1158

if(ret < 0){

1224

1159

exitcode = EXIT_FAILURE;

1225

1160

} else {

1227

1162

}

1228

1163

goto end;

1229

1164

}

1230

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

1231

1181

{

1232

1182

AvahiServerConfig config;

1233

1183

/* Do not publish any local Zeroconf records */

1256

1206

1257

1207

/* Create the Avahi service browser */

1258

1208

sb = avahi_s_service_browser_new(mc.server, if_index,

1259

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1260

NULL, 0, browse_callback, NULL);

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1210

NULL, 0, browse_callback, &mc);

1261

1211

if(sb == NULL){

1262

1212

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

1263

1213

avahi_strerror(avahi_server_errno(mc.server)));