/mandos/release : revision 176

47

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

48

sockaddr_in6, PF_INET6,

49

SOCK_STREAM, INET6_ADDRSTRLEN,

50

uid_t, gid_t */

51

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

50

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

51

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

52

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

53

struct in6_addr, inet_pton(),

54

connect() */

55

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

56

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

57

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

55

58

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

56

59

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

57

60

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

58

61

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

59

62

SIOCSIFFLAGS, if_indextoname(),

60

63

if_nametoindex(), IF_NAMESIZE */

64

#include <netinet/in.h>

61

65

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

62

66

getuid(), getgid(), setuid(),

63

67

setgid() */

64

#include <netinet/in.h>

65

68

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

66

69

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

67

70

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

98

101

99

102

#define BUFFER_SIZE 256

100

103

104

/*

105

#define PATHDIR "/conf/conf.d/mandos"

106

*/

107

108

#define PATHDIR "/conf/conf.d/mandos"

109

#define SECKEY "seckey.txt"

110

#define PUBKEY "pubkey.txt"

111

101

112

bool debug = false;

102

static const char *keydir = "/conf/conf.d/mandos";

103

113

static const char mandos_protocol_version[] = "1";

104

const char *argp_program_version = "password-request 1.0";

114

const char *argp_program_version = "mandos-client 1.0";

105

115

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

106

116

107

117

/* Used for passing in values through the Avahi callback functions */

112

122

unsigned int dh_bits;

113

123

gnutls_dh_params_t dh_params;

114

124

const char *priority;

125

gpgme_ctx_t ctx;

115

126

} mandos_context;

116

127

117

128

/*

132

143

}

133

144

134

145

/*

135

* Decrypt OpenPGP data using keyrings in HOMEDIR.

136

* Returns -1 on error

146

* Initialize GPGME.

137

147

*/

138

static ssize_t pgp_packet_decrypt (const char *cryptotext,

139

size_t crypto_size,

140

char **plaintext,

141

const char *homedir){

142

gpgme_data_t dh_crypto, dh_plain;

143

gpgme_ctx_t ctx;

148

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

149

const char *pubkey, const char *tempdir){

150

int ret;

144

151

gpgme_error_t rc;

145

ssize_t ret;

146

size_t plaintext_capacity = 0;

147

ssize_t plaintext_length = 0;

148

152

gpgme_engine_info_t engine_info;

149

153

154

155

/*

156

* Helper function to insert pub and seckey to the enigne keyring.

157

*/

158

bool import_key(const char *filename){

159

int fd;

160

gpgme_data_t pgp_data;

161

162

fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

163

if(fd == -1){

164

perror("open");

165

return false;

166

}

167

168

rc = gpgme_data_new_from_fd(&pgp_data, fd);

169

if (rc != GPG_ERR_NO_ERROR){

170

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

171

gpgme_strsource(rc), gpgme_strerror(rc));

172

return false;

173

}

174

175

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

176

if (rc != GPG_ERR_NO_ERROR){

177

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

178

gpgme_strsource(rc), gpgme_strerror(rc));

179

return false;

180

}

181

182

ret = TEMP_FAILURE_RETRY(close(fd));

183

if(ret == -1){

184

perror("close");

185

}

186

gpgme_data_release(pgp_data);

187

return true;

188

}

189

150

190

if (debug){

151

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

191

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

152

192

}

153

193

154

194

/* Init GPGME */

157

197

if (rc != GPG_ERR_NO_ERROR){

158

198

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

159

199

gpgme_strsource(rc), gpgme_strerror(rc));

160

return -1;

200

return false;

161

201

}

162

202

163

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

203

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

164

204

rc = gpgme_get_engine_info (&engine_info);

165

205

if (rc != GPG_ERR_NO_ERROR){

166

206

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

167

207

gpgme_strsource(rc), gpgme_strerror(rc));

168

return -1;

208

return false;

169

209

}

170

210

while(engine_info != NULL){

171

211

if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){

172

212

gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,

173

engine_info->file_name, homedir);

213

engine_info->file_name, tempdir);

174

214

break;

175

215

}

176

216

engine_info = engine_info->next;

177

217

}

178

218

if(engine_info == NULL){

179

fprintf(stderr, "Could not set GPGME home dir to %s\n", homedir);

180

return -1;

219

fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

220

return false;

221

}

222

223

/* Create new GPGME "context" */

224

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

225

if (rc != GPG_ERR_NO_ERROR){

226

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

227

gpgme_strsource(rc), gpgme_strerror(rc));

228

return false;

229

}

230

231

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

232

return false;

233

}

234

235

return true;

236

}

237

238

/*

239

* Decrypt OpenPGP data.

240

* Returns -1 on error

241

*/

242

static ssize_t pgp_packet_decrypt (const mandos_context *mc,

243

const char *cryptotext,

244

size_t crypto_size,

245

char **plaintext){

246

gpgme_data_t dh_crypto, dh_plain;

247

gpgme_error_t rc;

248

ssize_t ret;

249

size_t plaintext_capacity = 0;

250

ssize_t plaintext_length = 0;

251

252

if (debug){

253

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

181

254

}

182

255

183

256

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

198

271

return -1;

199

272

}

200

273

201

/* Create new GPGME "context" */

202

rc = gpgme_new(&ctx);

203

if (rc != GPG_ERR_NO_ERROR){

204

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

205

gpgme_strsource(rc), gpgme_strerror(rc));

206

plaintext_length = -1;

207

goto decrypt_end;

208

}

209

210

274

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

211

275

data buffer */

212

rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);

276

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

213

277

if (rc != GPG_ERR_NO_ERROR){

214

278

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

215

279

gpgme_strsource(rc), gpgme_strerror(rc));

216

280

plaintext_length = -1;

281

if (debug){

282

gpgme_decrypt_result_t result;

283

result = gpgme_op_decrypt_result(mc->ctx);

284

if (result == NULL){

285

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

286

} else {

287

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

288

result->unsupported_algorithm);

289

fprintf(stderr, "Wrong key usage: %u\n",

290

result->wrong_key_usage);

291

if(result->file_name != NULL){

292

fprintf(stderr, "File name: %s\n", result->file_name);

293

}

294

gpgme_recipient_t recipient;

295

recipient = result->recipients;

296

if(recipient){

297

while(recipient != NULL){

298

fprintf(stderr, "Public key algorithm: %s\n",

299

gpgme_pubkey_algo_name(recipient->pubkey_algo));

300

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

301

fprintf(stderr, "Secret key available: %s\n",

302

recipient->status == GPG_ERR_NO_SECKEY

303

? "No" : "Yes");

304

recipient = recipient->next;

305

}

306

}

307

}

308

}

217

309

goto decrypt_end;

218

310

}

219

311

221

313

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

222

314

}

223

315

224

if (debug){

225

gpgme_decrypt_result_t result;

226

result = gpgme_op_decrypt_result(ctx);

227

if (result == NULL){

228

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

229

} else {

230

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

231

result->unsupported_algorithm);

232

fprintf(stderr, "Wrong key usage: %u\n",

233

result->wrong_key_usage);

234

if(result->file_name != NULL){

235

fprintf(stderr, "File name: %s\n", result->file_name);

236

}

237

gpgme_recipient_t recipient;

238

recipient = result->recipients;

239

if(recipient){

240

while(recipient != NULL){

241

fprintf(stderr, "Public key algorithm: %s\n",

242

gpgme_pubkey_algo_name(recipient->pubkey_algo));

243

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

244

fprintf(stderr, "Secret key available: %s\n",

245

recipient->status == GPG_ERR_NO_SECKEY

246

? "No" : "Yes");

247

recipient = recipient->next;

248

}

249

}

250

}

251

}

252

253

316

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

254

317

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

255

perror("pgpme_data_seek");

318

perror("gpgme_data_seek");

256

319

plaintext_length = -1;

257

320

goto decrypt_end;

258

321

}

282

345

}

283

346

plaintext_length += ret;

284

347

}

285

348

286

349

if(debug){

287

350

fprintf(stderr, "Decrypted password is: ");

288

351

for(ssize_t i = 0; i < plaintext_length; i++){

349

412

}

350

413

351

414

if(debug){

352

fprintf(stderr, "Attempting to use OpenPGP certificate %s"

353

" and keyfile %s as GnuTLS credentials\n", pubkeyfilename,

415

fprintf(stderr, "Attempting to use OpenPGP public key %s and"

416

" secret key %s as GnuTLS credentials\n", pubkeyfilename,

354

417

seckeyfilename);

355

418

}

356

419

361

424

fprintf(stderr,

362

425

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

363

426

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

364

fprintf(stdout, "The GnuTLS error is: %s\n",

427

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

365

428

safer_gnutls_strerror(ret));

366

429

goto globalfail;

367

430

}

381

444

}

382

445

383

446

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

384

447

385

448

return 0;

386

449

387

450

globalfail:

388

451

389

452

gnutls_certificate_free_credentials(mc->cred);

390

453

gnutls_global_deinit();

454

gnutls_dh_params_deinit(mc->dh_params);

391

455

return -1;

392

393

456

}

394

457

395

458

static int init_gnutls_session(mandos_context *mc,

467

530

perror("socket");

468

531

return -1;

469

532

}

470

533

471

534

if(debug){

472

535

if(if_indextoname((unsigned int)if_index, interface) == NULL){

473

536

perror("if_indextoname");

512

575

perror("connect");

513

576

return -1;

514

577

}

515

578

516

579

const char *out = mandos_protocol_version;

517

580

written = 0;

518

581

while (true){

536

599

}

537

600

}

538

601

}

539

602

540

603

if(debug){

541

604

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

542

605

}

543

606

544

607

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

545

608

546

609

do{

547

610

ret = gnutls_handshake (session);

548

611

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

562

625

fprintf(stderr, "Retrieving pgp encrypted password from %s\n",

563

626

ip);

564

627

}

565

628

566

629

while(true){

567

630

buffer_capacity = adjustbuffer(&buffer, buffer_length,

568

631

buffer_capacity);

612

675

gnutls_bye (session, GNUTLS_SHUT_RDWR);

613

676

614

677

if (buffer_length > 0){

615

decrypted_buffer_size = pgp_packet_decrypt(buffer,

678

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

616

679

buffer_length,

617

&decrypted_buffer,

618

keydir);

680

&decrypted_buffer);

619

681

if (decrypted_buffer_size >= 0){

620

682

written = 0;

621

683

while(written < (size_t) decrypted_buffer_size){

644

706

645

707

mandos_end:

646

708

free(buffer);

647

close(tcp_sd);

709

ret = TEMP_FAILURE_RETRY(close(tcp_sd));

710

if(ret == -1){

711

perror("close");

712

}

648

713

gnutls_deinit (session);

649

714

return retval;

650

715

}

746

811

}

747

812

}

748

813

749

/* Combines file name and path and returns the malloced new

750

string. some sane checks could/should be added */

751

static char *combinepath(const char *first, const char *second){

752

char *tmp;

753

int ret = asprintf(&tmp, "%s/%s", first, second);

754

if(ret < 0){

755

return NULL;

756

}

757

return tmp;

758

}

759

760

761

814

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

762

815

AvahiSServiceBrowser *sb = NULL;

763

816

int error;

769

822

uid_t uid;

770

823

gid_t gid;

771

824

char *connect_to = NULL;

825

char tempdir[] = "/tmp/mandosXXXXXX";

772

826

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

773

char *pubkeyfilename = NULL;

774

char *seckeyfilename = NULL;

775

const char *pubkeyname = "pubkey.txt";

776

const char *seckeyname = "seckey.txt";

827

const char *seckey = PATHDIR "/" SECKEY;

828

const char *pubkey = PATHDIR "/" PUBKEY;

829

777

830

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

778

.dh_bits = 1024, .priority = "SECURE256"};

831

.dh_bits = 1024, .priority = "SECURE256"

832

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

779

833

bool gnutls_initalized = false;

834

bool gpgme_initalized = false;

780

835

781

836

{

782

837

struct argp_option options[] = {

783

838

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

784

839

.doc = "Debug mode", .group = 3 },

785

840

{ .name = "connect", .key = 'c',

786

.arg = "IP",

787

.doc = "Connect directly to a sepcified mandos server",

841

.arg = "ADDRESS:PORT",

842

.doc = "Connect directly to a specific Mandos server",

788

843

.group = 1 },

789

844

{ .name = "interface", .key = 'i',

790

.arg = "INTERFACE",

791

.doc = "Interface that Avahi will conntect through",

792

.group = 1 },

793

{ .name = "keydir", .key = 'd',

794

.arg = "KEYDIR",

795

.doc = "Directory where the openpgp keyring is",

845

.arg = "NAME",

846

.doc = "Interface that will be used to search for Mandos"

847

" servers",

796

848

.group = 1 },

797

849

{ .name = "seckey", .key = 's',

798

.arg = "SECKEY",

799

.doc = "Secret openpgp key for gnutls authentication",

850

.arg = "FILE",

851

.doc = "OpenPGP secret key file base name",

800

852

.group = 1 },

801

853

{ .name = "pubkey", .key = 'p',

802

.arg = "PUBKEY",

803

.doc = "Public openpgp key for gnutls authentication",

854

.arg = "FILE",

855

.doc = "OpenPGP public key file base name",

804

856

.group = 2 },

805

857

{ .name = "dh-bits", .key = 129,

806

858

.arg = "BITS",

807

.doc = "dh-bits to use in gnutls communication",

859

.doc = "Bit length of the prime number used in the"

860

" Diffie-Hellman key exchange",

808

861

.group = 2 },

809

862

{ .name = "priority", .key = 130,

810

.arg = "PRIORITY",

811

.doc = "GNUTLS priority", .group = 1 },

863

.arg = "STRING",

864

.doc = "GnuTLS priority string for the TLS handshake",

865

.group = 1 },

812

866

{ .name = NULL }

813

867

};

814

815

868

816

869

error_t parse_opt (int key, char *arg,

817

870

struct argp_state *state) {

818

871

/* Get the INPUT argument from `argp_parse', which we know is

819

872

a pointer to our plugin list pointer. */

820

873

switch (key) {

821

case 128:

874

case 128: /* --debug */

822

875

debug = true;

823

876

break;

824

case 'c':

877

case 'c': /* --connect */

825

878

connect_to = arg;

826

879

break;

827

case 'i':

880

case 'i': /* --interface */

828

881

interface = arg;

829

882

break;

830

case 'd':

831

keydir = arg;

832

break;

833

case 's':

834

seckeyname = arg;

835

break;

836

case 'p':

837

pubkeyname = arg;

838

break;

839

case 129:

883

case 's': /* --seckey */

884

seckey = arg;

885

break;

886

case 'p': /* --pubkey */

887

pubkey = arg;

888

break;

889

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

840

890

errno = 0;

841

891

mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);

842

892

if (errno){

844

894

exit(EXIT_FAILURE);

845

895

}

846

896

break;

847

case 130:

897

case 130: /* --priority */

848

898

mc.priority = arg;

849

899

break;

850

900

case ARGP_KEY_ARG:

856

906

}

857

907

return 0;

858

908

}

859

909

860

910

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

861

911

.args_doc = "",

862

912

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

863

" passwords from mandos server" };

913

" passwords from a Mandos server" };

864

914

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

865

915

if (ret == ARGP_ERR_UNKNOWN){

866

916

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

868

918

goto end;

869

919

}

870

920

}

871

872

pubkeyfilename = combinepath(keydir, pubkeyname);

873

if (pubkeyfilename == NULL){

874

perror("combinepath");

875

exitcode = EXIT_FAILURE;

876

goto end;

877

}

878

879

seckeyfilename = combinepath(keydir, seckeyname);

880

if (seckeyfilename == NULL){

881

perror("combinepath");

882

exitcode = EXIT_FAILURE;

883

goto end;

884

}

885

886

ret = init_gnutls_global(&mc, pubkeyfilename, seckeyfilename);

887

if (ret == -1){

888

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

889

exitcode = EXIT_FAILURE;

890

goto end;

891

} else {

892

gnutls_initalized = true;

893

}

894

921

895

922

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

896

923

{

916

943

goto end;

917

944

}

918

945

}

919

close(sd);

946

ret = TEMP_FAILURE_RETRY(close(sd));

947

if(ret == -1){

948

perror("close");

949

}

920

950

}

921

951

922

952

uid = getuid();

932

962

perror("setgid");

933

963

}

934

964

965

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

966

if (ret == -1){

967

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

968

exitcode = EXIT_FAILURE;

969

goto end;

970

} else {

971

gnutls_initalized = true;

972

}

973

974

if(mkdtemp(tempdir) == NULL){

975

perror("mkdtemp");

976

tempdir[0] = '\0';

977

goto end;

978

}

979

980

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

981

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

982

exitcode = EXIT_FAILURE;

983

goto end;

984

} else {

985

gpgme_initalized = true;

986

}

987

935

988

if_index = (AvahiIfIndex) if_nametoindex(interface);

936

989

if(if_index == 0){

937

990

fprintf(stderr, "No such interface: \"%s\"\n", interface);

980

1033

exitcode = EXIT_FAILURE;

981

1034

goto end;

982

1035

}

983

1036

984

1037

{

985

1038

AvahiServerConfig config;

986

1039

/* Do not publish any local Zeroconf records */

989

1042

config.publish_addresses = 0;

990

1043

config.publish_workstation = 0;

991

1044

config.publish_domain = 0;

992

1045

993

1046

/* Allocate a new server */

994

1047

mc.server = avahi_server_new(avahi_simple_poll_get

995

1048

(mc.simple_poll), &config, NULL,

996

1049

NULL, &error);

997

1050

998

1051

/* Free the Avahi configuration data */

999

1052

avahi_server_config_free(&config);

1000

1053

}

1020

1073

}

1021

1074

1022

1075

/* Run the main loop */

1023

1076

1024

1077

if (debug){

1025

1078

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

1026

1079

}

1028

1081

avahi_simple_poll_loop(mc.simple_poll);

1029

1082

1030

1083

end:

1031

1084

1032

1085

if (debug){

1033

1086

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

1034

1087

}

1039

1092

1040

1093

if (mc.server != NULL)

1041

1094

avahi_server_free(mc.server);

1042

1095

1043

1096

if (mc.simple_poll != NULL)

1044

1097

avahi_simple_poll_free(mc.simple_poll);

1045

free(pubkeyfilename);

1046

free(seckeyfilename);

1047

1098

1048

1099

if (gnutls_initalized){

1049

1100

gnutls_certificate_free_credentials(mc.cred);

1050

1101

gnutls_global_deinit ();

1051

}

1052

1102

gnutls_dh_params_deinit(mc.dh_params);

1103

}

1104

1105

if(gpgme_initalized){

1106

gpgme_release(mc.ctx);

1107

}

1108

1109

/* Removes the temp directory used by GPGME */

1110

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

1111

DIR *d;

1112

struct dirent *direntry;

1113

d = opendir(tempdir);

1114

if(d == NULL){

1115

perror("opendir");

1116

} else {

1117

while(true){

1118

direntry = readdir(d);

1119

if(direntry == NULL){

1120

break;

1121

}

1122

if (direntry->d_type == DT_REG){

1123

char *fullname = NULL;

1124

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

1125

direntry->d_name);

1126

if(ret < 0){

1127

perror("asprintf");

1128

continue;

1129

}

1130

ret = unlink(fullname);

1131

if(ret == -1){

1132

fprintf(stderr, "unlink(\"%s\"): %s",

1133

fullname, strerror(errno));

1134

}

1135

free(fullname);

1136

}

1137

}

1138

closedir(d);

1139

}

1140

ret = rmdir(tempdir);

1141

if(ret == -1){

1142

perror("rmdir");

1143

}

1144

}

1145

1053

1146

return exitcode;

1054

1147

}