/mandos/trunk : revision 162

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 "pupkey.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

114

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

105

115

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

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;

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

}

149

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 */

155

195

gpgme_check_version(NULL);

156

196

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

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

163

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

202

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

318

perror("pgpme_data_seek");

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();

391

454

return -1;

392

393

455

}

394

456

395

457

static int init_gnutls_session(mandos_context *mc,

467

529

perror("socket");

468

530

return -1;

469

531

}

470

532

471

533

if(debug){

472

534

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

473

535

perror("if_indextoname");

512

574

perror("connect");

513

575

return -1;

514

576

}

515

577

516

578

const char *out = mandos_protocol_version;

517

579

written = 0;

518

580

while (true){

536

598

}

537

599

}

538

600

}

539

601

540

602

if(debug){

541

603

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

542

604

}

543

605

544

606

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

545

607

546

608

do{

547

609

ret = gnutls_handshake (session);

548

610

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

562

624

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

563

625

ip);

564

626

}

565

627

566

628

while(true){

567

629

buffer_capacity = adjustbuffer(&buffer, buffer_length,

568

630

buffer_capacity);

612

674

gnutls_bye (session, GNUTLS_SHUT_RDWR);

613

675

614

676

if (buffer_length > 0){

615

decrypted_buffer_size = pgp_packet_decrypt(buffer,

677

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

616

678

buffer_length,

617

&decrypted_buffer,

618

keydir);

679

&decrypted_buffer);

619

680

if (decrypted_buffer_size >= 0){

620

681

written = 0;

621

682

while(written < (size_t) decrypted_buffer_size){

636

697

} else {

637

698

retval = -1;

638

699

}

700

} else {

701

retval = -1;

639

702

}

640

703

641

704

/* Shutdown procedure */

642

705

643

706

mandos_end:

644

707

free(buffer);

645

close(tcp_sd);

708

ret = TEMP_FAILURE_RETRY(close(tcp_sd));

709

if(ret == -1){

710

perror("close");

711

}

646

712

gnutls_deinit (session);

647

713

return retval;

648

714

}

744

810

}

745

811

}

746

812

747

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

748

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

749

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

750

char *tmp;

751

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

752

if(ret < 0){

753

return NULL;

754

}

755

return tmp;

756

}

757

758

759

813

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

760

814

AvahiSServiceBrowser *sb = NULL;

761

815

int error;

767

821

uid_t uid;

768

822

gid_t gid;

769

823

char *connect_to = NULL;

824

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

770

825

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

771

char *pubkeyfilename = NULL;

772

char *seckeyfilename = NULL;

773

const char *pubkeyname = "pubkey.txt";

774

const char *seckeyname = "seckey.txt";

826

const char *seckey = PATHDIR "/" SECKEY;

827

const char *pubkey = PATHDIR "/" PUBKEY;

828

775

829

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

776

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

830

.dh_bits = 1024, .priority = "SECURE256"

831

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

777

832

bool gnutls_initalized = false;

833

bool pgpme_initalized = false;

778

834

779

835

{

780

836

struct argp_option options[] = {

781

837

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

782

838

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

783

839

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

784

.arg = "IP",

785

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

840

.arg = "ADDRESS:PORT",

841

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

786

842

.group = 1 },

787

843

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

788

.arg = "INTERFACE",

789

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

790

.group = 1 },

791

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

792

.arg = "KEYDIR",

793

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

844

.arg = "NAME",

845

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

846

" servers",

794

847

.group = 1 },

795

848

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

796

.arg = "SECKEY",

797

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

849

.arg = "FILE",

850

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

798

851

.group = 1 },

799

852

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

800

.arg = "PUBKEY",

801

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

853

.arg = "FILE",

854

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

802

855

.group = 2 },

803

856

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

804

857

.arg = "BITS",

805

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

858

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

859

" Diffie-Hellman key exchange",

806

860

.group = 2 },

807

861

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

808

.arg = "PRIORITY",

809

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

862

.arg = "STRING",

863

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

864

.group = 1 },

810

865

{ .name = NULL }

811

866

};

812

813

867

814

868

error_t parse_opt (int key, char *arg,

815

869

struct argp_state *state) {

816

870

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

817

871

a pointer to our plugin list pointer. */

818

872

switch (key) {

819

case 128:

873

case 128: /* --debug */

820

874

debug = true;

821

875

break;

822

case 'c':

876

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

823

877

connect_to = arg;

824

878

break;

825

case 'i':

879

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

826

880

interface = arg;

827

881

break;

828

case 'd':

829

keydir = arg;

830

break;

831

case 's':

832

seckeyname = arg;

833

break;

834

case 'p':

835

pubkeyname = arg;

836

break;

837

case 129:

882

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

883

seckey = arg;

884

break;

885

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

886

pubkey = arg;

887

break;

888

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

838

889

errno = 0;

839

890

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

840

891

if (errno){

842

893

exit(EXIT_FAILURE);

843

894

}

844

895

break;

845

case 130:

896

case 130: /* --priority */

846

897

mc.priority = arg;

847

898

break;

848

899

case ARGP_KEY_ARG:

854

905

}

855

906

return 0;

856

907

}

857

908

858

909

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

859

910

.args_doc = "",

860

911

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

861

" passwords from mandos server" };

912

" passwords from a Mandos server" };

862

913

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

863

914

if (ret == ARGP_ERR_UNKNOWN){

864

915

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

866

917

goto end;

867

918

}

868

919

}

869

870

pubkeyfilename = combinepath(keydir, pubkeyname);

871

if (pubkeyfilename == NULL){

872

perror("combinepath");

873

exitcode = EXIT_FAILURE;

874

goto end;

875

}

876

920

877

seckeyfilename = combinepath(keydir, seckeyname);

878

if (seckeyfilename == NULL){

879

perror("combinepath");

880

exitcode = EXIT_FAILURE;

881

goto end;

882

}

883

884

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

921

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

885

922

if (ret == -1){

886

923

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

887

924

exitcode = EXIT_FAILURE;

889

926

} else {

890

927

gnutls_initalized = true;

891

928

}

929

930

if(mkdtemp(tempdir) == NULL){

931

perror("mkdtemp");

932

tempdir[0] = '\0';

933

goto end;

934

}

935

936

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

937

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

938

exitcode = EXIT_FAILURE;

939

goto end;

940

} else {

941

pgpme_initalized = true;

942

}

892

943

893

944

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

894

945

{

914

965

goto end;

915

966

}

916

967

}

917

close(sd);

968

ret = TEMP_FAILURE_RETRY(close(sd));

969

if(ret == -1){

970

perror("close");

971

}

918

972

}

919

973

920

974

uid = getuid();

978

1032

exitcode = EXIT_FAILURE;

979

1033

goto end;

980

1034

}

981

1035

982

1036

{

983

1037

AvahiServerConfig config;

984

1038

/* Do not publish any local Zeroconf records */

987

1041

config.publish_addresses = 0;

988

1042

config.publish_workstation = 0;

989

1043

config.publish_domain = 0;

990

1044

991

1045

/* Allocate a new server */

992

1046

mc.server = avahi_server_new(avahi_simple_poll_get

993

1047

(mc.simple_poll), &config, NULL,

994

1048

NULL, &error);

995

1049

996

1050

/* Free the Avahi configuration data */

997

1051

avahi_server_config_free(&config);

998

1052

}

1018

1072

}

1019

1073

1020

1074

/* Run the main loop */

1021

1075

1022

1076

if (debug){

1023

1077

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

1024

1078

}

1026

1080

avahi_simple_poll_loop(mc.simple_poll);

1027

1081

1028

1082

end:

1029

1083

1030

1084

if (debug){

1031

1085

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

1032

1086

}

1037

1091

1038

1092

if (mc.server != NULL)

1039

1093

avahi_server_free(mc.server);

1040

1094

1041

1095

if (mc.simple_poll != NULL)

1042

1096

avahi_simple_poll_free(mc.simple_poll);

1043

free(pubkeyfilename);

1044

free(seckeyfilename);

1045

1097

1046

1098

if (gnutls_initalized){

1047

1099

gnutls_certificate_free_credentials(mc.cred);

1048

1100

gnutls_global_deinit ();

1049

1101

}

1050

1102

1103

if(pgpme_initalized){

1104

gpgme_release(mc.ctx);

1105

}

1106

1107

/* Removes the temp directory used by GPGME */

1108

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

1109

DIR *d;

1110

struct dirent *direntry;

1111

d = opendir(tempdir);

1112

if(d == NULL){

1113

perror("opendir");

1114

} else {

1115

while(true){

1116

direntry = readdir(d);

1117

if(direntry == NULL){

1118

break;

1119

}

1120

if (direntry->d_type == DT_REG){

1121

char *fullname = NULL;

1122

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

1123

direntry->d_name);

1124

if(ret < 0){

1125

perror("asprintf");

1126

continue;

1127

}

1128

ret = unlink(fullname);

1129

if(ret == -1){

1130

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

1131

fullname, strerror(errno));

1132

}

1133

free(fullname);

1134

}

1135

}

1136

}

1137

ret = rmdir(tempdir);

1138

if(ret == -1){

1139

perror("rmdir");

1140

}

1141

}

1142

1051

1143

return exitcode;

1052

1144

}