/mandos/release : revision 24.1.71

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

217

if (debug){

282

218

gpgme_decrypt_result_t result;

283

result = gpgme_op_decrypt_result(mc->ctx);

219

result = gpgme_op_decrypt_result(ctx);

284

220

if (result == NULL){

285

221

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

286

222

} else {

315

251

316

252

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

317

253

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

318

perror("gpgme_data_seek");

254

perror("pgpme_data_seek");

319

255

plaintext_length = -1;

320

256

goto decrypt_end;

321

257

}

345

281

}

346

282

plaintext_length += ret;

347

283

}

348

284

349

285

if(debug){

350

286

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

351

287

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

412

348

}

413

349

414

350

if(debug){

415

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

416

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

351

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

352

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

417

353

seckeyfilename);

418

354

}

419

355

424

360

fprintf(stderr,

425

361

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

426

362

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

427

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

363

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

428

364

safer_gnutls_strerror(ret));

429

365

goto globalfail;

430

366

}

444

380

}

445

381

446

382

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

447

383

448

384

return 0;

449

385

450

386

globalfail:

451

387

452

388

gnutls_certificate_free_credentials(mc->cred);

453

389

gnutls_global_deinit();

454

gnutls_dh_params_deinit(mc->dh_params);

455

390

return -1;

391

456

392

}

457

393

458

394

static int init_gnutls_session(mandos_context *mc,

530

466

perror("socket");

531

467

return -1;

532

468

}

533

469

534

470

if(debug){

535

471

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

536

472

perror("if_indextoname");

575

511

perror("connect");

576

512

return -1;

577

513

}

578

514

579

515

const char *out = mandos_protocol_version;

580

516

written = 0;

581

517

while (true){

599

535

}

600

536

}

601

537

}

602

538

603

539

if(debug){

604

540

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

605

541

}

606

542

607

543

gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);

608

544

609

545

do{

610

546

ret = gnutls_handshake (session);

611

547

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

625

561

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

626

562

ip);

627

563

}

628

564

629

565

while(true){

630

566

buffer_capacity = adjustbuffer(&buffer, buffer_length,

631

567

buffer_capacity);

675

611

gnutls_bye (session, GNUTLS_SHUT_RDWR);

676

612

677

613

if (buffer_length > 0){

678

decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,

614

decrypted_buffer_size = pgp_packet_decrypt(buffer,

679

615

buffer_length,

680

&decrypted_buffer);

616

&decrypted_buffer,

617

keydir);

681

618

if (decrypted_buffer_size >= 0){

682

619

written = 0;

683

620

while(written < (size_t) decrypted_buffer_size){

706

643

707

644

mandos_end:

708

645

free(buffer);

709

ret = TEMP_FAILURE_RETRY(close(tcp_sd));

710

if(ret == -1){

711

perror("close");

712

}

646

close(tcp_sd);

713

647

gnutls_deinit (session);

714

648

return retval;

715

649

}

811

745

}

812

746

}

813

747

748

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

749

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

750

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

751

char *tmp;

752

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

753

if(ret < 0){

754

return NULL;

755

}

756

return tmp;

757

}

758

759

814

760

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

815

761

AvahiSServiceBrowser *sb = NULL;

816

762

int error;

822

768

uid_t uid;

823

769

gid_t gid;

824

770

char *connect_to = NULL;

825

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

826

771

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

827

const char *seckey = PATHDIR "/" SECKEY;

828

const char *pubkey = PATHDIR "/" PUBKEY;

829

772

char *pubkeyfilename = NULL;

773

char *seckeyfilename = NULL;

774

const char *pubkeyname = "pubkey.txt";

775

const char *seckeyname = "seckey.txt";

830

776

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

831

.dh_bits = 1024, .priority = "SECURE256"

832

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

777

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

833

778

bool gnutls_initalized = false;

834

bool gpgme_initalized = false;

835

779

836

780

{

837

781

struct argp_option options[] = {

838

782

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

839

783

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

840

784

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

841

.arg = "ADDRESS:PORT",

842

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

785

.arg = "IP",

786

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

843

787

.group = 1 },

844

788

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

845

.arg = "NAME",

846

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

847

" servers",

789

.arg = "INTERFACE",

790

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

791

.group = 1 },

792

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

793

.arg = "KEYDIR",

794

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

848

795

.group = 1 },

849

796

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

850

.arg = "FILE",

851

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

797

.arg = "SECKEY",

798

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

852

799

.group = 1 },

853

800

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

854

.arg = "FILE",

855

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

801

.arg = "PUBKEY",

802

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

856

803

.group = 2 },

857

804

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

858

805

.arg = "BITS",

859

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

860

" Diffie-Hellman key exchange",

806

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

861

807

.group = 2 },

862

808

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

863

.arg = "STRING",

864

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

865

.group = 1 },

809

.arg = "PRIORITY",

810

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

866

811

{ .name = NULL }

867

812

};

813

868

814

869

815

error_t parse_opt (int key, char *arg,

870

816

struct argp_state *state) {

871

817

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

872

818

a pointer to our plugin list pointer. */

873

819

switch (key) {

874

case 128: /* --debug */

820

case 128:

875

821

debug = true;

876

822

break;

877

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

823

case 'c':

878

824

connect_to = arg;

879

825

break;

880

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

826

case 'i':

881

827

interface = arg;

882

828

break;

883

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

884

seckey = arg;

885

break;

886

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

887

pubkey = arg;

888

break;

889

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

829

case 'd':

830

keydir = arg;

831

break;

832

case 's':

833

seckeyname = arg;

834

break;

835

case 'p':

836

pubkeyname = arg;

837

break;

838

case 129:

890

839

errno = 0;

891

840

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

892

841

if (errno){

894

843

exit(EXIT_FAILURE);

895

844

}

896

845

break;

897

case 130: /* --priority */

846

case 130:

898

847

mc.priority = arg;

899

848

break;

900

849

case ARGP_KEY_ARG:

906

855

}

907

856

return 0;

908

857

}

909

858

910

859

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

911

860

.args_doc = "",

912

861

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

913

" passwords from a Mandos server" };

862

" passwords from mandos server" };

914

863

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

915

864

if (ret == ARGP_ERR_UNKNOWN){

916

865

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

918

867

goto end;

919

868

}

920

869

}

870

871

pubkeyfilename = combinepath(keydir, pubkeyname);

872

if (pubkeyfilename == NULL){

873

perror("combinepath");

874

exitcode = EXIT_FAILURE;

875

goto end;

876

}

921

877

922

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

878

seckeyfilename = combinepath(keydir, seckeyname);

879

if (seckeyfilename == NULL){

880

perror("combinepath");

881

exitcode = EXIT_FAILURE;

882

goto end;

883

}

884

885

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

923

886

if (ret == -1){

924

887

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

925

888

exitcode = EXIT_FAILURE;

927

890

} else {

928

891

gnutls_initalized = true;

929

892

}

930

931

if(mkdtemp(tempdir) == NULL){

932

perror("mkdtemp");

933

tempdir[0] = '\0';

934

goto end;

935

}

936

937

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

938

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

939

exitcode = EXIT_FAILURE;

940

goto end;

941

} else {

942

gpgme_initalized = true;

943

}

944

893

945

894

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

946

895

{

966

915

goto end;

967

916

}

968

917

}

969

ret = TEMP_FAILURE_RETRY(close(sd));

970

if(ret == -1){

971

perror("close");

972

}

918

close(sd);

973

919

}

974

920

975

921

uid = getuid();

1033

979

exitcode = EXIT_FAILURE;

1034

980

goto end;

1035

981

}

1036

982

1037

983

{

1038

984

AvahiServerConfig config;

1039

985

/* Do not publish any local Zeroconf records */

1042

988

config.publish_addresses = 0;

1043

989

config.publish_workstation = 0;

1044

990

config.publish_domain = 0;

1045

991

1046

992

/* Allocate a new server */

1047

993

mc.server = avahi_server_new(avahi_simple_poll_get

1048

994

(mc.simple_poll), &config, NULL,

1049

995

NULL, &error);

1050

996

1051

997

/* Free the Avahi configuration data */

1052

998

avahi_server_config_free(&config);

1053

999

}

1073

1019

}

1074

1020

1075

1021

/* Run the main loop */

1076

1022

1077

1023

if (debug){

1078

1024

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

1079

1025

}

1081

1027

avahi_simple_poll_loop(mc.simple_poll);

1082

1028

1083

1029

end:

1084

1030

1085

1031

if (debug){

1086

1032

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

1087

1033

}

1092

1038

1093

1039

if (mc.server != NULL)

1094

1040

avahi_server_free(mc.server);

1095

1041

1096

1042

if (mc.simple_poll != NULL)

1097

1043

avahi_simple_poll_free(mc.simple_poll);

1098

1044

free(pubkeyfilename);

1045

free(seckeyfilename);

1046

1099

1047

if (gnutls_initalized){

1100

1048

gnutls_certificate_free_credentials(mc.cred);

1101

1049

gnutls_global_deinit ();

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

1050

}

1051

1146

1052

return exitcode;

1147

1053

}