/mandos/release : revision 97

47

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

48

sockaddr_in6, PF_INET6,

49

SOCK_STREAM, INET6_ADDRSTRLEN,

50

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

51

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

50

uid_t, gid_t */

51

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

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 */

58

55

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

59

56

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

60

57

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

61

58

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

62

59

SIOCSIFFLAGS, if_indextoname(),

63

60

if_nametoindex(), IF_NAMESIZE */

64

#include <netinet/in.h>

65

61

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

66

62

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

67

63

setgid() */

64

#include <netinet/in.h>

68

65

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

69

66

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

70

67

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

101

98

102

99

#define BUFFER_SIZE 256

103

100

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

112

101

bool debug = false;

102

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

113

103

static const char mandos_protocol_version[] = "1";

114

104

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

115

105

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

122

112

unsigned int dh_bits;

123

113

gnutls_dh_params_t dh_params;

124

114

const char *priority;

125

gpgme_ctx_t ctx;

126

115

} mandos_context;

127

116

128

117

/*

143

132

}

144

133

145

134

/*

146

* Initialize GPGME.

135

* Decrypt OpenPGP data using keyrings in HOMEDIR.

136

* Returns -1 on error

147

137

*/

148

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

149

const char *pubkey, const char *tempdir){

150

int ret;

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;

151

144

gpgme_error_t rc;

145

ssize_t ret;

146

size_t plaintext_capacity = 0;

147

ssize_t plaintext_length = 0;

152

148

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

}

189

149

190

150

if (debug){

191

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

151

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

192

152

}

193

153

194

154

/* Init GPGME */

195

155

gpgme_check_version(NULL);

196

156

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

197

157

if (rc != GPG_ERR_NO_ERROR){

198

158

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

199

159

gpgme_strsource(rc), gpgme_strerror(rc));

200

return false;

160

return -1;

201

161

}

202

203

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

162

163

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

204

164

rc = gpgme_get_engine_info (&engine_info);

205

165

if (rc != GPG_ERR_NO_ERROR){

206

166

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

207

167

gpgme_strsource(rc), gpgme_strerror(rc));

208

return false;

168

return -1;

209

169

}

210

170

while(engine_info != NULL){

211

171

if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){

212

172

gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,

213

engine_info->file_name, tempdir);

173

engine_info->file_name, homedir);

214

174

break;

215

175

}

216

176

engine_info = engine_info->next;

217

177

}

218

178

if(engine_info == NULL){

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");

179

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

180

return -1;

254

181

}

255

182

256

183

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

271

198

return -1;

272

199

}

273

200

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

274

210

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

275

211

data buffer */

276

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

212

rc = gpgme_op_decrypt(ctx, dh_crypto, dh_plain);

277

213

if (rc != GPG_ERR_NO_ERROR){

278

214

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

279

215

gpgme_strsource(rc), gpgme_strerror(rc));

280

216

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

}

309

217

goto decrypt_end;

310

218

}

311

219

313

221

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

314

222

}

315

223

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

316

253

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

317

254

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

318

255

perror("pgpme_data_seek");

345

282

}

346

283

plaintext_length += ret;

347

284

}

348

285

349

286

if(debug){

350

287

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

351

288

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

412

349

}

413

350

414

351

if(debug){

415

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

416

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

352

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

353

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

417

354

seckeyfilename);

418

355

}

419

356

424

361

fprintf(stderr,

425

362

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

426

363

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

427

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

364

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

428

365

safer_gnutls_strerror(ret));

429

366

goto globalfail;

430

367

}

444

381

}

445

382

446

383

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

447

384

448

385

return 0;

449

386

450

387

globalfail:

451

388

452

389

gnutls_certificate_free_credentials(mc->cred);

453

390

gnutls_global_deinit();

454

391

return -1;

392

455

393

}

456

394

457

395

static int init_gnutls_session(mandos_context *mc,

529

467

perror("socket");

530

468

return -1;

531

469

}

532

470

533

471

if(debug){

534

472

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

535

473

perror("if_indextoname");

574

512

perror("connect");

575

513

return -1;

576

514

}

577

515

578

516

const char *out = mandos_protocol_version;

579

517

written = 0;

580

518

while (true){

598

536

}

599

537

}

600

538

}

601

539

602

540

if(debug){

603

541

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

604

542

}

605

543

606

544

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

607

545

608

546

do{

609

547

ret = gnutls_handshake (session);

610

548

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

624

562

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

625

563

ip);

626

564

}

627

565

628

566

while(true){

629

567

buffer_capacity = adjustbuffer(&buffer, buffer_length,

630

568

buffer_capacity);

674

612

gnutls_bye (session, GNUTLS_SHUT_RDWR);

675

613

676

614

if (buffer_length > 0){

677

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

615

decrypted_buffer_size = pgp_packet_decrypt(buffer,

678

616

buffer_length,

679

&decrypted_buffer);

617

&decrypted_buffer,

618

keydir);

680

619

if (decrypted_buffer_size >= 0){

681

620

written = 0;

682

621

while(written < (size_t) decrypted_buffer_size){

697

636

} else {

698

637

retval = -1;

699

638

}

700

} else {

701

retval = -1;

702

639

}

703

640

704

641

/* Shutdown procedure */

705

642

706

643

mandos_end:

707

644

free(buffer);

708

ret = TEMP_FAILURE_RETRY(close(tcp_sd));

709

if(ret == -1){

710

perror("close");

711

}

645

close(tcp_sd);

712

646

gnutls_deinit (session);

713

647

return retval;

714

648

}

810

744

}

811

745

}

812

746

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

813

759

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

814

760

AvahiSServiceBrowser *sb = NULL;

815

761

int error;

821

767

uid_t uid;

822

768

gid_t gid;

823

769

char *connect_to = NULL;

824

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

825

770

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

826

const char *seckey = PATHDIR "/" SECKEY;

827

const char *pubkey = PATHDIR "/" PUBKEY;

828

771

char *pubkeyfilename = NULL;

772

char *seckeyfilename = NULL;

773

const char *pubkeyname = "pubkey.txt";

774

const char *seckeyname = "seckey.txt";

829

775

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

830

.dh_bits = 1024, .priority = "SECURE256"

831

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

776

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

832

777

bool gnutls_initalized = false;

833

bool pgpme_initalized = false;

834

778

835

779

{

836

780

struct argp_option options[] = {

837

781

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

838

782

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

839

783

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

840

.arg = "ADDRESS:PORT",

841

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

784

.arg = "IP",

785

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

842

786

.group = 1 },

843

787

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

844

.arg = "NAME",

845

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

846

" servers",

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",

847

794

.group = 1 },

848

795

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

849

.arg = "FILE",

850

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

796

.arg = "SECKEY",

797

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

851

798

.group = 1 },

852

799

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

853

.arg = "FILE",

854

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

800

.arg = "PUBKEY",

801

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

855

802

.group = 2 },

856

803

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

857

804

.arg = "BITS",

858

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

859

" Diffie-Hellman key exchange",

805

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

860

806

.group = 2 },

861

807

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

862

.arg = "STRING",

863

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

864

.group = 1 },

808

.arg = "PRIORITY",

809

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

865

810

{ .name = NULL }

866

811

};

812

867

813

868

814

error_t parse_opt (int key, char *arg,

869

815

struct argp_state *state) {

870

816

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

871

817

a pointer to our plugin list pointer. */

872

818

switch (key) {

873

case 128: /* --debug */

819

case 128:

874

820

debug = true;

875

821

break;

876

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

822

case 'c':

877

823

connect_to = arg;

878

824

break;

879

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

825

case 'i':

880

826

interface = arg;

881

827

break;

882

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

883

seckey = arg;

884

break;

885

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

886

pubkey = arg;

887

break;

888

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

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:

889

838

errno = 0;

890

839

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

891

840

if (errno){

893

842

exit(EXIT_FAILURE);

894

843

}

895

844

break;

896

case 130: /* --priority */

845

case 130:

897

846

mc.priority = arg;

898

847

break;

899

848

case ARGP_KEY_ARG:

905

854

}

906

855

return 0;

907

856

}

908

857

909

858

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

910

859

.args_doc = "",

911

860

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

912

" passwords from a Mandos server" };

861

" passwords from mandos server" };

913

862

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

914

863

if (ret == ARGP_ERR_UNKNOWN){

915

864

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

917

866

goto end;

918

867

}

919

868

}

869

870

pubkeyfilename = combinepath(keydir, pubkeyname);

871

if (pubkeyfilename == NULL){

872

perror("combinepath");

873

exitcode = EXIT_FAILURE;

874

goto end;

875

}

920

876

921

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

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);

922

885

if (ret == -1){

923

886

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

924

887

exitcode = EXIT_FAILURE;

926

889

} else {

927

890

gnutls_initalized = true;

928

891

}

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

}

943

892

944

893

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

945

894

{

965

914

goto end;

966

915

}

967

916

}

968

ret = TEMP_FAILURE_RETRY(close(sd));

969

if(ret == -1){

970

perror("close");

971

}

917

close(sd);

972

918

}

973

919

974

920

uid = getuid();

1032

978

exitcode = EXIT_FAILURE;

1033

979

goto end;

1034

980

}

1035

981

1036

982

{

1037

983

AvahiServerConfig config;

1038

984

/* Do not publish any local Zeroconf records */

1041

987

config.publish_addresses = 0;

1042

988

config.publish_workstation = 0;

1043

989

config.publish_domain = 0;

1044

990

1045

991

/* Allocate a new server */

1046

992

mc.server = avahi_server_new(avahi_simple_poll_get

1047

993

(mc.simple_poll), &config, NULL,

1048

994

NULL, &error);

1049

995

1050

996

/* Free the Avahi configuration data */

1051

997

avahi_server_config_free(&config);

1052

998

}

1072

1018

}

1073

1019

1074

1020

/* Run the main loop */

1075

1021

1076

1022

if (debug){

1077

1023

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

1078

1024

}

1080

1026

avahi_simple_poll_loop(mc.simple_poll);

1081

1027

1082

1028

end:

1083

1029

1084

1030

if (debug){

1085

1031

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

1086

1032

}

1091

1037

1092

1038

if (mc.server != NULL)

1093

1039

avahi_server_free(mc.server);

1094

1040

1095

1041

if (mc.simple_poll != NULL)

1096

1042

avahi_simple_poll_free(mc.simple_poll);

1097

1043

free(pubkeyfilename);

1044

free(seckeyfilename);

1045

1098

1046

if (gnutls_initalized){

1099

1047

gnutls_certificate_free_credentials(mc.cred);

1100

1048

gnutls_global_deinit ();

1101

1049

}

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

1050

1143

1051

return exitcode;

1144

1052

}