/mandos/trunk : revision 305

36

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

37

38

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

39

stdout, ferror(), remove() */

39

stdout, ferror(), sscanf(),

40

remove() */

40

41

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

41

42

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

42

43

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

43

srand(), strtof() */

44

srand() */

44

45

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

45

46

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

46

47

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

55

56

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

56

57

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

57

58

*/

58

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

59

strtoimax() */

59

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

60

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

61

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

62

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

75

argp_state, struct argp,

76

argp_parse(), ARGP_KEY_ARG,

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

78

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

79

sigaction(), SIGTERM, sigaction,

80

sig_atomic_t */

81

82

78

#ifdef __linux__

83

79

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

84

#endif /* __linux__ */

80

#endif

85

81

86

82

/* Avahi */

87

83

/* All Avahi types, constants and functions

133

129

gpgme_ctx_t ctx;

134

130

} mandos_context;

135

131

136

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

137

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

138

.dh_bits = 1024, .priority = "SECURE256"

139

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

140

141

132

/*

142

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

143

* 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,

144

135

* "buffer_length" is how much is already used.

145

136

*/

146

size_t incbuffer(char **buffer, size_t buffer_length,

137

size_t adjustbuffer(char **buffer, size_t buffer_length,

147

138

size_t buffer_capacity){

148

139

if(buffer_length + BUFFER_SIZE > buffer_capacity){

149

140

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

158

149

/*

159

150

* Initialize GPGME.

160

151

*/

161

static bool init_gpgme(const char *seckey,

152

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

162

153

const char *pubkey, const char *tempdir){

163

154

int ret;

164

155

gpgme_error_t rc;

185

176

return false;

186

177

}

187

178

188

rc = gpgme_op_import(mc.ctx, pgp_data);

179

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

189

180

if(rc != GPG_ERR_NO_ERROR){

190

181

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

191

182

gpgme_strsource(rc), gpgme_strerror(rc));

201

192

}

202

193

203

194

if(debug){

204

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

195

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

205

196

}

206

197

207

198

/* Init GPGME */

234

225

}

235

226

236

227

/* Create new GPGME "context" */

237

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

228

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

238

229

if(rc != GPG_ERR_NO_ERROR){

239

230

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

240

231

gpgme_strsource(rc), gpgme_strerror(rc));

252

243

* Decrypt OpenPGP data.

253

244

* Returns -1 on error

254

245

*/

255

static ssize_t pgp_packet_decrypt(const char *cryptotext,

246

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

247

const char *cryptotext,

256

248

size_t crypto_size,

257

249

char **plaintext){

258

250

gpgme_data_t dh_crypto, dh_plain;

285

277

286

278

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

287

279

data buffer */

288

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

280

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

289

281

if(rc != GPG_ERR_NO_ERROR){

290

282

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

291

283

gpgme_strsource(rc), gpgme_strerror(rc));

292

284

plaintext_length = -1;

293

285

if(debug){

294

286

gpgme_decrypt_result_t result;

295

result = gpgme_op_decrypt_result(mc.ctx);

287

result = gpgme_op_decrypt_result(mc->ctx);

296

288

if(result == NULL){

297

289

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

298

290

} else {

334

326

335

327

*plaintext = NULL;

336

328

while(true){

337

plaintext_capacity = incbuffer(plaintext,

329

plaintext_capacity = adjustbuffer(plaintext,

338

330

(size_t)plaintext_length,

339

331

plaintext_capacity);

340

332

if(plaintext_capacity == 0){

341

perror("incbuffer");

333

perror("adjustbuffer");

342

334

plaintext_length = -1;

343

335

goto decrypt_end;

344

336

}

390

382

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

391

383

}

392

384

393

static int init_gnutls_global(const char *pubkeyfilename,

385

static int init_gnutls_global(mandos_context *mc,

386

const char *pubkeyfilename,

394

387

const char *seckeyfilename){

395

388

int ret;

396

389

414

407

}

415

408

416

409

/* OpenPGP credentials */

417

gnutls_certificate_allocate_credentials(&mc.cred);

410

gnutls_certificate_allocate_credentials(&mc->cred);

418

411

if(ret != GNUTLS_E_SUCCESS){

419

412

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

420

413

from

432

425

}

433

426

434

427

ret = gnutls_certificate_set_openpgp_key_file

435

(mc.cred, pubkeyfilename, seckeyfilename,

428

(mc->cred, pubkeyfilename, seckeyfilename,

436

429

GNUTLS_OPENPGP_FMT_BASE64);

437

430

if(ret != GNUTLS_E_SUCCESS){

438

431

fprintf(stderr,

444

437

}

445

438

446

439

/* GnuTLS server initialization */

447

ret = gnutls_dh_params_init(&mc.dh_params);

440

ret = gnutls_dh_params_init(&mc->dh_params);

448

441

if(ret != GNUTLS_E_SUCCESS){

449

442

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

450

443

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

451

444

goto globalfail;

452

445

}

453

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

446

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

454

447

if(ret != GNUTLS_E_SUCCESS){

455

448

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

456

449

safer_gnutls_strerror(ret));

457

450

goto globalfail;

458

451

}

459

452

460

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

453

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

461

454

462

455

return 0;

463

456

464

457

globalfail:

465

458

466

gnutls_certificate_free_credentials(mc.cred);

459

gnutls_certificate_free_credentials(mc->cred);

467

460

gnutls_global_deinit();

468

gnutls_dh_params_deinit(mc.dh_params);

461

gnutls_dh_params_deinit(mc->dh_params);

469

462

return -1;

470

463

}

471

464

472

static int init_gnutls_session(gnutls_session_t *session){

465

static int init_gnutls_session(mandos_context *mc,

466

gnutls_session_t *session){

473

467

int ret;

474

468

/* GnuTLS session creation */

475

469

ret = gnutls_init(session, GNUTLS_SERVER);

480

474

481

475

{

482

476

const char *err;

483

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

477

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

484

478

if(ret != GNUTLS_E_SUCCESS){

485

479

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

486

480

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

491

485

}

492

486

493

487

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

494

mc.cred);

488

mc->cred);

495

489

if(ret != GNUTLS_E_SUCCESS){

496

490

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

497

491

safer_gnutls_strerror(ret));

503

497

gnutls_certificate_server_set_request(*session,

504

498

GNUTLS_CERT_IGNORE);

505

499

506

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

500

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

507

501

508

502

return 0;

509

503

}

515

509

/* Called when a Mandos server is found */

516

510

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

517

511

AvahiIfIndex if_index,

518

int af){

512

mandos_context *mc, int af){

519

513

int ret, tcp_sd;

520

514

ssize_t sret;

521

515

union {

544

538

return -1;

545

539

}

546

540

547

ret = init_gnutls_session(&session);

541

ret = init_gnutls_session(mc, &session);

548

542

if(ret != 0){

549

543

return -1;

550

544

}

691

685

}

692

686

693

687

while(true){

694

buffer_capacity = incbuffer(&buffer, buffer_length,

688

buffer_capacity = adjustbuffer(&buffer, buffer_length,

695

689

buffer_capacity);

696

690

if(buffer_capacity == 0){

697

perror("incbuffer");

691

perror("adjustbuffer");

698

692

retval = -1;

699

693

goto mandos_end;

700

694

}

739

733

gnutls_bye(session, GNUTLS_SHUT_RDWR);

740

734

741

735

if(buffer_length > 0){

742

decrypted_buffer_size = pgp_packet_decrypt(buffer,

736

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

743

737

buffer_length,

744

738

&decrypted_buffer);

745

739

if(decrypted_buffer_size >= 0){

791

785

AVAHI_GCC_UNUSED AvahiStringList *txt,

792

786

AVAHI_GCC_UNUSED AvahiLookupResultFlags

793

787

flags,

794

AVAHI_GCC_UNUSED void* userdata){

788

void* userdata){

789

mandos_context *mc = userdata;

795

790

assert(r);

796

791

797

792

/* Called whenever a service has been resolved successfully or

802

797

case AVAHI_RESOLVER_FAILURE:

803

798

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

804

799

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

805

avahi_strerror(avahi_server_errno(mc.server)));

800

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

806

801

break;

807

802

808

803

case AVAHI_RESOLVER_FOUND:

814

809

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

815

810

ip, (intmax_t)interface, port);

816

811

}

817

int ret = start_mandos_communication(ip, port, interface,

812

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

818

813

avahi_proto_to_af(proto));

819

814

if(ret == 0){

820

avahi_simple_poll_quit(mc.simple_poll);

815

avahi_simple_poll_quit(mc->simple_poll);

821

816

}

822

817

}

823

818

}

833

828

const char *domain,

834

829

AVAHI_GCC_UNUSED AvahiLookupResultFlags

835

830

flags,

836

AVAHI_GCC_UNUSED void* userdata){

831

void* userdata){

832

mandos_context *mc = userdata;

837

833

assert(b);

838

834

839

835

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

844

840

case AVAHI_BROWSER_FAILURE:

845

841

846

842

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

847

avahi_strerror(avahi_server_errno(mc.server)));

848

avahi_simple_poll_quit(mc.simple_poll);

843

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

844

avahi_simple_poll_quit(mc->simple_poll);

849

845

return;

850

846

851

847

case AVAHI_BROWSER_NEW:

854

850

the callback function is called the Avahi server will free the

855

851

resolver for us. */

856

852

857

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

853

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

858

854

protocol, name, type, domain,

859

855

AVAHI_PROTO_INET6, 0,

860

resolve_callback, NULL)))

856

resolve_callback, mc)))

861

857

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

862

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

858

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

863

859

break;

864

860

865

861

case AVAHI_BROWSER_REMOVE:

874

870

}

875

871

}

876

872

877

sig_atomic_t quit_now = 0;

878

879

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

880

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

881

if(quit_now){

882

return;

883

}

884

quit_now = 1;

885

int old_errno = errno;

886

if(mc.simple_poll != NULL){

887

avahi_simple_poll_quit(mc.simple_poll);

888

}

889

errno = old_errno;

890

}

891

892

873

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

893

874

AvahiSServiceBrowser *sb = NULL;

894

875

int error;

895

876

int ret;

896

877

intmax_t tmpmax;

897

char *tmp;

878

int numchars;

898

879

int exitcode = EXIT_SUCCESS;

899

880

const char *interface = "eth0";

900

881

struct ifreq network;

908

889

const char *seckey = PATHDIR "/" SECKEY;

909

890

const char *pubkey = PATHDIR "/" PUBKEY;

910

891

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" };

892

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

893

.dh_bits = 1024, .priority = "SECURE256"

894

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

915

895

bool gnutls_initialized = false;

916

896

bool gpgme_initialized = false;

917

float delay = 2.5f;

918

919

struct sigaction old_sigterm_action;

920

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

897

double delay = 2.5;

921

898

922

899

{

923

900

struct argp_option options[] = {

975

952

pubkey = arg;

976

953

break;

977

954

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

978

errno = 0;

979

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

980

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

981

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'){

982

958

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

983

959

exit(EXIT_FAILURE);

984

960

}

988

964

mc.priority = arg;

989

965

break;

990

966

case 131: /* --delay */

991

errno = 0;

992

delay = strtof(arg, &tmp);

993

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'){

994

969

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

995

970

exit(EXIT_FAILURE);

996

971

}

1017

992

}

1018

993

}

1019

994

1020

if(not debug){

1021

avahi_set_log_function(empty_log);

1022

}

1023

1024

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

1025

from the signal handler */

1026

/* Initialize the pseudo-RNG for Avahi */

1027

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

1028

mc.simple_poll = avahi_simple_poll_new();

1029

if(mc.simple_poll == NULL){

1030

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

1031

exitcode = EXIT_FAILURE;

1032

goto end;

1033

}

1034

1035

sigemptyset(&sigterm_action.sa_mask);

1036

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

1037

if(ret == -1){

1038

perror("sigaddset");

1039

exitcode = EXIT_FAILURE;

1040

goto end;

1041

}

1042

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

1043

if(ret == -1){

1044

perror("sigaddset");

1045

exitcode = EXIT_FAILURE;

1046

goto end;

1047

}

1048

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

1049

if(ret == -1){

1050

perror("sigaddset");

1051

exitcode = EXIT_FAILURE;

1052

goto end;

1053

}

1054

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

1055

if(ret == -1){

1056

perror("sigaction");

1057

exitcode = EXIT_FAILURE;

1058

goto end;

1059

}

1060

1061

995

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

1062

996

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

1063

997

#ifdef __linux__

1069

1003

restore_loglevel = false;

1070

1004

perror("klogctl");

1071

1005

}

1072

#endif /* __linux__ */

1006

#endif

1073

1007

1074

1008

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1075

1009

if(sd < 0){

1082

1016

perror("klogctl");

1083

1017

}

1084

1018

}

1085

#endif /* __linux__ */

1019

#endif

1086

1020

goto end;

1087

1021

}

1088

1022

strcpy(network.ifr_name, interface);

1096

1030

perror("klogctl");

1097

1031

}

1098

1032

}

1099

#endif /* __linux__ */

1033

#endif

1100

1034

exitcode = EXIT_FAILURE;

1101

1035

goto end;

1102

1036

}

1113

1047

perror("klogctl");

1114

1048

}

1115

1049

}

1116

#endif /* __linux__ */

1050

#endif

1117

1051

goto end;

1118

1052

}

1119

1053

}

1143

1077

perror("klogctl");

1144

1078

}

1145

1079

}

1146

#endif /* __linux__ */

1080

#endif

1147

1081

}

1148

1082

1149

1083

uid = getuid();

1160

1094

perror("setuid");

1161

1095

}

1162

1096

1163

ret = init_gnutls_global(pubkey, seckey);

1097

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

1164

1098

if(ret == -1){

1165

1099

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

1166

1100

exitcode = EXIT_FAILURE;

1175

1109

}

1176

1110

tempdir_created = true;

1177

1111

1178

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

1112

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

1179

1113

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

1180

1114

exitcode = EXIT_FAILURE;

1181

1115

goto end;

1202

1136

goto end;

1203

1137

}

1204

1138

uint16_t port;

1205

errno = 0;

1206

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

1207

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

1208

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'){

1209

1142

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

1210

1143

exitcode = EXIT_FAILURE;

1211

1144

goto end;

1220

1153

} else {

1221

1154

af = AF_INET;

1222

1155

}

1223

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

1156

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

1157

af);

1224

1158

if(ret < 0){

1225

1159

exitcode = EXIT_FAILURE;

1226

1160

} else {

1228

1162

}

1229

1163

goto end;

1230

1164

}

1231

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

1232

1181

{

1233

1182

AvahiServerConfig config;

1234

1183

/* Do not publish any local Zeroconf records */

1258

1207

/* Create the Avahi service browser */

1259

1208

sb = avahi_s_service_browser_new(mc.server, if_index,

1260

1209

AVAHI_PROTO_INET6, "_mandos._tcp",

1261

NULL, 0, browse_callback, NULL);

1210

NULL, 0, browse_callback, &mc);

1262

1211

if(sb == NULL){

1263

1212

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

1264

1213

avahi_strerror(avahi_server_errno(mc.server)));