/mandos/trunk : revision 266

48

#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

49

sockaddr_in6, PF_INET6,

50

SOCK_STREAM, INET6_ADDRSTRLEN,

51

uid_t, gid_t, open(), opendir(), DIR */

51

uid_t, gid_t, open(), opendir(),

52

DIR */

52

53

#include <sys/stat.h> /* open() */

53

54

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

54

55

struct in6_addr, inet_pton(),

55

56

connect() */

56

57

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

57

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

58

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

59

*/

58

60

#include <inttypes.h> /* PRIu16, SCNu16 */

59

61

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

60

62

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

90

92

gnutls_*

91

93

init_gnutls_session(),

92

94

GNUTLS_* */

93

#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),

95

#include <gnutls/openpgp.h>

96

/* gnutls_certificate_set_openpgp_key_file(),

94

97

GNUTLS_OPENPGP_FMT_BASE64 */

95

98

96

99

/* GPGME */

129

132

*/

130

133

size_t adjustbuffer(char **buffer, size_t buffer_length,

131

134

size_t buffer_capacity){

132

if (buffer_length + BUFFER_SIZE > buffer_capacity){

135

if(buffer_length + BUFFER_SIZE > buffer_capacity){

133

136

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

134

if (buffer == NULL){

137

if(buffer == NULL){

135

138

return 0;

136

139

}

137

140

buffer_capacity += BUFFER_SIZE;

163

166

}

164

167

165

168

rc = gpgme_data_new_from_fd(&pgp_data, fd);

166

if (rc != GPG_ERR_NO_ERROR){

169

if(rc != GPG_ERR_NO_ERROR){

167

170

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

168

171

gpgme_strsource(rc), gpgme_strerror(rc));

169

172

return false;

170

173

}

171

174

172

175

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

173

if (rc != GPG_ERR_NO_ERROR){

176

if(rc != GPG_ERR_NO_ERROR){

174

177

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

175

178

gpgme_strsource(rc), gpgme_strerror(rc));

176

179

return false;

184

187

return true;

185

188

}

186

189

187

if (debug){

190

if(debug){

188

191

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

189

192

}

190

193

191

194

/* Init GPGME */

192

195

gpgme_check_version(NULL);

193

196

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

194

if (rc != GPG_ERR_NO_ERROR){

197

if(rc != GPG_ERR_NO_ERROR){

195

198

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

196

199

gpgme_strsource(rc), gpgme_strerror(rc));

197

200

return false;

198

201

}

199

202

200

203

/* Set GPGME home directory for the OpenPGP engine only */

201

rc = gpgme_get_engine_info (&engine_info);

202

if (rc != GPG_ERR_NO_ERROR){

204

rc = gpgme_get_engine_info(&engine_info);

205

if(rc != GPG_ERR_NO_ERROR){

203

206

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

204

207

gpgme_strsource(rc), gpgme_strerror(rc));

205

208

return false;

219

222

220

223

/* Create new GPGME "context" */

221

224

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

222

if (rc != GPG_ERR_NO_ERROR){

225

if(rc != GPG_ERR_NO_ERROR){

223

226

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

224

227

gpgme_strsource(rc), gpgme_strerror(rc));

225

228

return false;

226

229

}

227

230

228

if (not import_key(pubkey) or not import_key(seckey)){

231

if(not import_key(pubkey) or not import_key(seckey)){

229

232

return false;

230

233

}

231

234

236

239

* Decrypt OpenPGP data.

237

240

* Returns -1 on error

238

241

*/

239

static ssize_t pgp_packet_decrypt (const mandos_context *mc,

240

const char *cryptotext,

241

size_t crypto_size,

242

char **plaintext){

242

static ssize_t pgp_packet_decrypt(const mandos_context *mc,

243

const char *cryptotext,

244

size_t crypto_size,

245

char **plaintext){

243

246

gpgme_data_t dh_crypto, dh_plain;

244

247

gpgme_error_t rc;

245

248

ssize_t ret;

246

249

size_t plaintext_capacity = 0;

247

250

ssize_t plaintext_length = 0;

248

251

249

if (debug){

252

if(debug){

250

253

fprintf(stderr, "Trying to decrypt OpenPGP data\n");

251

254

}

252

255

253

256

/* Create new GPGME data buffer from memory cryptotext */

254

257

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

255

258

0);

256

if (rc != GPG_ERR_NO_ERROR){

259

if(rc != GPG_ERR_NO_ERROR){

257

260

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

258

261

gpgme_strsource(rc), gpgme_strerror(rc));

259

262

return -1;

261

264

262

265

/* Create new empty GPGME data buffer for the plaintext */

263

266

rc = gpgme_data_new(&dh_plain);

264

if (rc != GPG_ERR_NO_ERROR){

267

if(rc != GPG_ERR_NO_ERROR){

265

268

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

266

269

gpgme_strsource(rc), gpgme_strerror(rc));

267

270

gpgme_data_release(dh_crypto);

271

274

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

272

275

data buffer */

273

276

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

274

if (rc != GPG_ERR_NO_ERROR){

277

if(rc != GPG_ERR_NO_ERROR){

275

278

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

276

279

gpgme_strsource(rc), gpgme_strerror(rc));

277

280

plaintext_length = -1;

278

if (debug){

281

if(debug){

279

282

gpgme_decrypt_result_t result;

280

283

result = gpgme_op_decrypt_result(mc->ctx);

281

if (result == NULL){

284

if(result == NULL){

282

285

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

283

286

} else {

284

287

fprintf(stderr, "Unsupported algorithm: %s\n",

311

314

}

312

315

313

316

/* Seek back to the beginning of the GPGME plaintext data buffer */

314

if (gpgme_data_seek(dh_plain, (off_t) 0, SEEK_SET) == -1){

317

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

315

318

perror("gpgme_data_seek");

316

319

plaintext_length = -1;

317

320

goto decrypt_end;

322

325

plaintext_capacity = adjustbuffer(plaintext,

323

326

(size_t)plaintext_length,

324

327

plaintext_capacity);

325

if (plaintext_capacity == 0){

328

if(plaintext_capacity == 0){

326

329

perror("adjustbuffer");

327

330

plaintext_length = -1;

328

331

goto decrypt_end;

331

334

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

332

335

BUFFER_SIZE);

333

336

/* Print the data, if any */

334

if (ret == 0){

337

if(ret == 0){

335

338

/* EOF */

336

339

break;

337

340

}

361

364

return plaintext_length;

362

365

}

363

366

364

static const char * safer_gnutls_strerror (int value) {

365

const char *ret = gnutls_strerror (value); /* Spurious warning */

366

if (ret == NULL)

367

static const char * safer_gnutls_strerror(int value) {

368

const char *ret = gnutls_strerror(value); /* Spurious warning */

369

if(ret == NULL)

367

370

ret = "(unknown)";

368

371

return ret;

369

372

}

384

387

}

385

388

386

389

ret = gnutls_global_init();

387

if (ret != GNUTLS_E_SUCCESS) {

388

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

389

safer_gnutls_strerror(ret));

390

if(ret != GNUTLS_E_SUCCESS) {

391

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

392

safer_gnutls_strerror(ret));

390

393

return -1;

391

394

}

392

395

393

if (debug){

396

if(debug){

394

397

/* "Use a log level over 10 to enable all debugging options."

395

398

* - GnuTLS manual

396

399

*/

400

403

401

404

/* OpenPGP credentials */

402

405

gnutls_certificate_allocate_credentials(&mc->cred);

403

if (ret != GNUTLS_E_SUCCESS){

404

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

405

warning */

406

safer_gnutls_strerror(ret));

407

gnutls_global_deinit ();

406

if(ret != GNUTLS_E_SUCCESS){

407

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

408

warning */

409

safer_gnutls_strerror(ret));

410

gnutls_global_deinit();

408

411

return -1;

409

412

}

410

413

417

420

ret = gnutls_certificate_set_openpgp_key_file

418

421

(mc->cred, pubkeyfilename, seckeyfilename,

419

422

GNUTLS_OPENPGP_FMT_BASE64);

420

if (ret != GNUTLS_E_SUCCESS) {

423

if(ret != GNUTLS_E_SUCCESS) {

421

424

fprintf(stderr,

422

425

"Error[%d] while reading the OpenPGP key pair ('%s',"

423

426

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

428

431

429

432

/* GnuTLS server initialization */

430

433

ret = gnutls_dh_params_init(&mc->dh_params);

431

if (ret != GNUTLS_E_SUCCESS) {

432

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

433

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

434

if(ret != GNUTLS_E_SUCCESS) {

435

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

436

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

434

437

goto globalfail;

435

438

}

436

439

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

437

if (ret != GNUTLS_E_SUCCESS) {

438

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

439

safer_gnutls_strerror(ret));

440

if(ret != GNUTLS_E_SUCCESS) {

441

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

442

safer_gnutls_strerror(ret));

440

443

goto globalfail;

441

444

}

442

445

457

460

int ret;

458

461

/* GnuTLS session creation */

459

462

ret = gnutls_init(session, GNUTLS_SERVER);

460

if (ret != GNUTLS_E_SUCCESS){

463

if(ret != GNUTLS_E_SUCCESS){

461

464

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

462

465

safer_gnutls_strerror(ret));

463

466

}

465

468

{

466

469

const char *err;

467

470

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

468

if (ret != GNUTLS_E_SUCCESS) {

471

if(ret != GNUTLS_E_SUCCESS) {

469

472

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

470

473

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

471

474

safer_gnutls_strerror(ret));

472

gnutls_deinit (*session);

475

gnutls_deinit(*session);

473

476

return -1;

474

477

}

475

478

}

476

479

477

480

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

478

481

mc->cred);

479

if (ret != GNUTLS_E_SUCCESS) {

482

if(ret != GNUTLS_E_SUCCESS) {

480

483

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

481

484

safer_gnutls_strerror(ret));

482

gnutls_deinit (*session);

485

gnutls_deinit(*session);

483

486

return -1;

484

487

}

485

488

486

489

/* ignore client certificate if any. */

487

gnutls_certificate_server_set_request (*session,

488

GNUTLS_CERT_IGNORE);

490

gnutls_certificate_server_set_request(*session,

491

GNUTLS_CERT_IGNORE);

489

492

490

gnutls_dh_set_prime_bits (*session, mc->dh_bits);

493

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

491

494

492

495

return 0;

493

496

}

513

516

char interface[IF_NAMESIZE];

514

517

gnutls_session_t session;

515

518

516

ret = init_gnutls_session (mc, &session);

517

if (ret != 0){

519

ret = init_gnutls_session(mc, &session);

520

if(ret != 0){

518

521

return -1;

519

522

}

520

523

542

545

/* It would be nice to have a way to detect if we were passed an

543

546

IPv4 address here. Now we assume an IPv6 address. */

544

547

ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);

545

if (ret < 0 ){

548

if(ret < 0 ){

546

549

perror("inet_pton");

547

550

return -1;

548

551

}

569

572

}

570

573

571

574

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

572

if (ret < 0){

575

if(ret < 0){

573

576

perror("connect");

574

577

return -1;

575

578

}

576

579

577

580

const char *out = mandos_protocol_version;

578

581

written = 0;

579

while (true){

582

while(true){

580

583

size_t out_size = strlen(out);

581

584

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

582

585

out_size - written));

583

if (ret == -1){

586

if(ret == -1){

584

587

perror("write");

585

588

retval = -1;

586

589

goto mandos_end;

589

592

if(written < out_size){

590

593

continue;

591

594

} else {

592

if (out == mandos_protocol_version){

595

if(out == mandos_protocol_version){

593

596

written = 0;

594

597

out = "\r\n";

595

598

} else {

602

605

fprintf(stderr, "Establishing TLS session with %s\n", ip);

603

606

}

604

607

605

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

608

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

606

609

607

610

do{

608

ret = gnutls_handshake (session);

611

ret = gnutls_handshake(session);

609

612

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

610

613

611

if (ret != GNUTLS_E_SUCCESS){

614

if(ret != GNUTLS_E_SUCCESS){

612

615

if(debug){

613

616

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

614

gnutls_perror (ret);

617

gnutls_perror(ret);

615

618

}

616

619

retval = -1;

617

620

goto mandos_end;

627

630

while(true){

628

631

buffer_capacity = adjustbuffer(&buffer, buffer_length,

629

632

buffer_capacity);

630

if (buffer_capacity == 0){

633

if(buffer_capacity == 0){

631

634

perror("adjustbuffer");

632

635

retval = -1;

633

636

goto mandos_end;

635

638

636

639

sret = gnutls_record_recv(session, buffer+buffer_length,

637

640

BUFFER_SIZE);

638

if (sret == 0){

641

if(sret == 0){

639

642

break;

640

643

}

641

if (sret < 0){

644

if(sret < 0){

642

645

switch(sret){

643

646

case GNUTLS_E_INTERRUPTED:

644

647

case GNUTLS_E_AGAIN:

645

648

break;

646

649

case GNUTLS_E_REHANDSHAKE:

647

650

do{

648

ret = gnutls_handshake (session);

651

ret = gnutls_handshake(session);

649

652

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

650

if (ret < 0){

653

if(ret < 0){

651

654

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

652

gnutls_perror (ret);

655

gnutls_perror(ret);

653

656

retval = -1;

654

657

goto mandos_end;

655

658

}

658

661

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

659

662

" encrypted session with Mandos server\n");

660

663

retval = -1;

661

gnutls_bye (session, GNUTLS_SHUT_RDWR);

664

gnutls_bye(session, GNUTLS_SHUT_RDWR);

662

665

goto mandos_end;

663

666

}

664

667

} else {

670

673

fprintf(stderr, "Closing TLS session\n");

671

674

}

672

675

673

gnutls_bye (session, GNUTLS_SHUT_RDWR);

676

gnutls_bye(session, GNUTLS_SHUT_RDWR);

674

677

675

if (buffer_length > 0){

678

if(buffer_length > 0){

676

679

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

677

680

buffer_length,

678

681

&decrypted_buffer);

679

if (decrypted_buffer_size >= 0){

682

if(decrypted_buffer_size >= 0){

680

683

written = 0;

681

684

while(written < (size_t) decrypted_buffer_size){

682

ret = (int)fwrite (decrypted_buffer + written, 1,

683

(size_t)decrypted_buffer_size - written,

684

stdout);

685

ret = (int)fwrite(decrypted_buffer + written, 1,

686

(size_t)decrypted_buffer_size - written,

687

stdout);

685

688

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

686

689

if(debug){

687

690

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

708

711

if(ret == -1){

709

712

perror("close");

710

713

}

711

gnutls_deinit (session);

714

gnutls_deinit(session);

712

715

return retval;

713

716

}

714

717

732

735

/* Called whenever a service has been resolved successfully or

733

736

timed out */

734

737

735

switch (event) {

738

switch(event) {

736

739

default:

737

740

case AVAHI_RESOLVER_FAILURE:

738

741

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

750

753

interface, port);

751

754

}

752

755

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

753

if (ret == 0){

756

if(ret == 0){

754

757

avahi_simple_poll_quit(mc->simple_poll);

755

758

}

756

759

}

774

777

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

775

778

is removed from the LAN */

776

779

777

switch (event) {

780

switch(event) {

778

781

default:

779

782

case AVAHI_BROWSER_FAILURE:

780

783

789

792

the callback function is called the Avahi server will free the

790

793

resolver for us. */

791

794

792

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

795

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

793

796

protocol, name, type, domain,

794

797

AVAHI_PROTO_INET6, 0,

795

798

resolve_callback, mc)))

864

867

{ .name = NULL }

865

868

};

866

869

867

error_t parse_opt (int key, char *arg,

868

struct argp_state *state) {

869

switch (key) {

870

error_t parse_opt(int key, char *arg,

871

struct argp_state *state) {

872

switch(key) {

870

873

case 128: /* --debug */

871

874

debug = true;

872

875

break;

893

896

mc.priority = arg;

894

897

break;

895

898

case ARGP_KEY_ARG:

896

argp_usage (state);

899

argp_usage(state);

897

900

case ARGP_KEY_END:

898

901

break;

899

902

default:

906

909

.args_doc = "",

907

910

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

908

911

" passwords from a Mandos server" };

909

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

910

if (ret == ARGP_ERR_UNKNOWN){

912

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

913

if(ret == ARGP_ERR_UNKNOWN){

911

914

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

912

915

exitcode = EXIT_FAILURE;

913

916

goto end;

948

951

gid = getgid();

949

952

950

953

ret = setuid(uid);

951

if (ret == -1){

954

if(ret == -1){

952

955

perror("setuid");

953

956

}

954

957

955

958

setgid(gid);

956

if (ret == -1){

959

if(ret == -1){

957

960

perror("setgid");

958

961

}

959

962

960

963

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

961

if (ret == -1){

964

if(ret == -1){

962

965

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

963

966

exitcode = EXIT_FAILURE;

964

967

goto end;

1013

1016

goto end;

1014

1017

}

1015

1018

1016

if (not debug){

1019

if(not debug){

1017

1020

avahi_set_log_function(empty_log);

1018

1021

}

1019

1022

1025

1023

1026

/* Allocate main Avahi loop object */

1024

1027

mc.simple_poll = avahi_simple_poll_new();

1025

if (mc.simple_poll == NULL) {

1028

if(mc.simple_poll == NULL) {

1026

1029

fprintf(stderr, "Avahi: Failed to create simple poll"

1027

1030

" object.\n");

1028

1031

exitcode = EXIT_FAILURE;

1048

1051

}

1049

1052

1050

1053

/* Check if creating the Avahi server object succeeded */

1051

if (mc.server == NULL) {

1054

if(mc.server == NULL) {

1052

1055

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

1053

1056

avahi_strerror(error));

1054

1057

exitcode = EXIT_FAILURE;

1060

1063

AVAHI_PROTO_INET6,

1061

1064

"_mandos._tcp", NULL, 0,

1062

1065

browse_callback, &mc);

1063

if (sb == NULL) {

1066

if(sb == NULL) {

1064

1067

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

1065

1068

avahi_strerror(avahi_server_errno(mc.server)));

1066

1069

exitcode = EXIT_FAILURE;

1069

1072

1070

1073

/* Run the main loop */

1071

1074

1072

if (debug){

1075

if(debug){

1073

1076

fprintf(stderr, "Starting Avahi loop search\n");

1074

1077

}

1075

1078

1077

1080

1078

1081

end:

1079

1082

1080

if (debug){

1083

if(debug){

1081

1084

fprintf(stderr, "%s exiting\n", argv[0]);

1082

1085

}

1083

1086

1084

1087

/* Cleanup things */

1085

if (sb != NULL)

1088

if(sb != NULL)

1086

1089

avahi_s_service_browser_free(sb);

1087

1090

1088

if (mc.server != NULL)

1091

if(mc.server != NULL)

1089

1092

avahi_server_free(mc.server);

1090

1093

1091

if (mc.simple_poll != NULL)

1094

if(mc.simple_poll != NULL)

1092

1095

avahi_simple_poll_free(mc.simple_poll);

1093

1096

1094

if (gnutls_initalized){

1097

if(gnutls_initalized){

1095

1098

gnutls_certificate_free_credentials(mc.cred);

1096

gnutls_global_deinit ();

1099

gnutls_global_deinit();

1097

1100

gnutls_dh_params_deinit(mc.dh_params);

1098

1101

}

1099

1102

1116

1119

if(direntry == NULL){

1117

1120

break;

1118

1121

}

1119

if (direntry->d_type == DT_REG){

1122

if(direntry->d_type == DT_REG){

1120

1123

char *fullname = NULL;

1121

1124

ret = asprintf(&fullname, "%s/%s", tempdir,

1122

1125

direntry->d_name);