/mandos/release : revision 237.8.1

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

30

*/

31

32

/* Needed by GPGME, specifically gpgme_data_seek() */

33

#ifndef _LARGEFILE_SOURCE

33

34

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

34

37

#define _FILE_OFFSET_BITS 64

38

#endif

35

39

36

40

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

37

41

38

42

#include <stdio.h> /* fprintf(), stderr, fwrite(),

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

#include <stdint.h> /* uint16_t, uint32_t */

42

45

#include <stddef.h> /* NULL, size_t, ssize_t */

43

#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,

44

srand() */

46

#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

47

strtof(), abort() */

45

48

#include <stdbool.h> /* bool, false, true */

46

49

#include <string.h> /* memset(), strcmp(), strlen(),

47

50

strerror(), asprintf(), strcpy() */

56

59

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

57

60

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

58

61

*/

59

#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */

62

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

63

strtoimax() */

60

64

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

61

65

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

62

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

66

#include <time.h> /* nanosleep(), time(), sleep() */

63

67

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

64

68

SIOCSIFFLAGS, if_indextoname(),

65

69

if_nametoindex(), IF_NAMESIZE */

67

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

68

72

*/

69

73

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

70

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

71

setgid() */

74

getuid(), getgid(), seteuid(),

75

setgid(), pause() */

72

76

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

73

77

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

74

78

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

75

79

argp_state, struct argp,

76

80

argp_parse(), ARGP_KEY_ARG,

77

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

78

#include <signal.h> /* sigemptyset(), sigaddset(), sigaction(), SIGTERM, sigaction */

82

#include <signal.h> /* sigemptyset(), sigaddset(),

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

86

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

87

79

88

#ifdef __linux__

80

89

#include <sys/klog.h> /* klogctl() */

81

#endif

90

#endif /* __linux__ */

82

91

83

92

/* Avahi */

84

93

/* All Avahi types, constants and functions

118

127

static const char mandos_protocol_version[] = "1";

119

128

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

120

129

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

130

static const char sys_class_net[] = "/sys/class/net";

131

char *connect_to = NULL;

121

132

122

133

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

123

134

typedef struct {

131

142

} mandos_context;

132

143

133

144

/* global context so signal handler can reach it*/

134

mandos_context mc;

145

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

146

.dh_bits = 1024, .priority = "SECURE256"

147

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

148

149

sig_atomic_t quit_now = 0;

150

int signal_received = 0;

135

151

136

152

/*

137

* Make additional room in "buffer" for at least BUFFER_SIZE

138

* additional bytes. "buffer_capacity" is how much is currently

139

* allocated, "buffer_length" is how much is already used.

153

* Make additional room in "buffer" for at least BUFFER_SIZE more

154

* bytes. "buffer_capacity" is how much is currently allocated,

155

* "buffer_length" is how much is already used.

140

156

*/

141

157

size_t incbuffer(char **buffer, size_t buffer_length,

142

158

size_t buffer_capacity){

155

171

*/

156

172

static bool init_gpgme(const char *seckey,

157

173

const char *pubkey, const char *tempdir){

158

int ret;

159

174

gpgme_error_t rc;

160

175

gpgme_engine_info_t engine_info;

161

176

164

179

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

165

180

*/

166

181

bool import_key(const char *filename){

182

int ret;

167

183

int fd;

168

184

gpgme_data_t pgp_data;

169

185

196

212

}

197

213

198

214

if(debug){

199

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

215

fprintf(stderr, "Initializing GPGME\n");

200

216

}

201

217

202

218

/* Init GPGME */

240

256

return false;

241

257

}

242

258

243

return true;

259

return true;

244

260

}

245

261

246

262

/*

300

316

}

301

317

gpgme_recipient_t recipient;

302

318

recipient = result->recipients;

303

if(recipient){

304

while(recipient != NULL){

305

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

306

gpgme_pubkey_algo_name(recipient->pubkey_algo));

307

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

308

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

309

recipient->status == GPG_ERR_NO_SECKEY

310

? "No" : "Yes");

311

recipient = recipient->next;

312

}

319

while(recipient != NULL){

320

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

321

gpgme_pubkey_algo_name(recipient->pubkey_algo));

322

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

323

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

324

recipient->status == GPG_ERR_NO_SECKEY

325

? "No" : "Yes");

326

recipient = recipient->next;

313

327

}

314

328

}

315

329

}

467

481

static int init_gnutls_session(gnutls_session_t *session){

468

482

int ret;

469

483

/* GnuTLS session creation */

470

ret = gnutls_init(session, GNUTLS_SERVER);

484

do {

485

ret = gnutls_init(session, GNUTLS_SERVER);

486

if(quit_now){

487

return -1;

488

}

489

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

471

490

if(ret != GNUTLS_E_SUCCESS){

472

491

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

473

492

safer_gnutls_strerror(ret));

475

494

476

495

{

477

496

const char *err;

478

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

497

do {

498

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

499

if(quit_now){

500

gnutls_deinit(*session);

501

return -1;

502

}

503

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

479

504

if(ret != GNUTLS_E_SUCCESS){

480

505

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

481

506

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

485

510

}

486

511

}

487

512

488

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

489

mc.cred);

513

do {

514

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

515

mc.cred);

516

if(quit_now){

517

gnutls_deinit(*session);

518

return -1;

519

}

520

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

490

521

if(ret != GNUTLS_E_SUCCESS){

491

522

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

492

523

safer_gnutls_strerror(ret));

495

526

}

496

527

497

528

/* ignore client certificate if any. */

498

gnutls_certificate_server_set_request(*session,

499

GNUTLS_CERT_IGNORE);

529

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

500

530

501

531

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

502

532

511

541

static int start_mandos_communication(const char *ip, uint16_t port,

512

542

AvahiIfIndex if_index,

513

543

int af){

514

int ret, tcp_sd;

544

int ret, tcp_sd = -1;

515

545

ssize_t sret;

516

546

union {

517

547

struct sockaddr_in in;

518

548

struct sockaddr_in6 in6;

519

549

} to;

520

550

char *buffer = NULL;

521

char *decrypted_buffer;

551

char *decrypted_buffer = NULL;

522

552

size_t buffer_length = 0;

523

553

size_t buffer_capacity = 0;

524

ssize_t decrypted_buffer_size;

525

554

size_t written;

526

int retval = 0;

555

int retval = -1;

527

556

gnutls_session_t session;

528

557

int pf; /* Protocol family */

529

558

559

errno = 0;

560

561

if(quit_now){

562

errno = EINTR;

563

return -1;

564

}

565

530

566

switch(af){

531

567

case AF_INET6:

532

568

pf = PF_INET6;

536

572

break;

537

573

default:

538

574

fprintf(stderr, "Bad address family: %d\n", af);

575

errno = EINVAL;

539

576

return -1;

540

577

}

541

578

551

588

552

589

tcp_sd = socket(pf, SOCK_STREAM, 0);

553

590

if(tcp_sd < 0){

591

int e = errno;

554

592

perror("socket");

555

return -1;

593

errno = e;

594

goto mandos_end;

595

}

596

597

if(quit_now){

598

errno = EINTR;

599

goto mandos_end;

556

600

}

557

601

558

602

memset(&to, 0, sizeof(to));

559

603

if(af == AF_INET6){

560

to.in6.sin6_family = (uint16_t)af;

604

to.in6.sin6_family = (sa_family_t)af;

561

605

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

562

606

} else { /* IPv4 */

563

607

to.in.sin_family = (sa_family_t)af;

564

608

ret = inet_pton(af, ip, &to.in.sin_addr);

565

609

}

566

610

if(ret < 0 ){

611

int e = errno;

567

612

perror("inet_pton");

568

return -1;

613

errno = e;

614

goto mandos_end;

569

615

}

570

616

if(ret == 0){

617

int e = errno;

571

618

fprintf(stderr, "Bad address: %s\n", ip);

572

return -1;

619

errno = e;

620

goto mandos_end;

573

621

}

574

622

if(af == AF_INET6){

575

623

to.in6.sin6_port = htons(port); /* Spurious warnings from

582

630

if(if_index == AVAHI_IF_UNSPEC){

583

631

fprintf(stderr, "An IPv6 link-local address is incomplete"

584

632

" without a network interface\n");

585

return -1;

633

errno = EINVAL;

634

goto mandos_end;

586

635

}

587

636

/* Set the network interface number as scope */

588

637

to.in6.sin6_scope_id = (uint32_t)if_index;

593

642

-Wunreachable-code */

594

643

}

595

644

645

if(quit_now){

646

errno = EINTR;

647

goto mandos_end;

648

}

649

596

650

if(debug){

597

651

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

598

652

char interface[IF_NAMESIZE];

625

679

}

626

680

}

627

681

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

628

687

if(af == AF_INET6){

629

688

ret = connect(tcp_sd, &to.in6, sizeof(to));

630

689

} else {

631

690

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

632

691

}

633

692

if(ret < 0){

634

perror("connect");

635

return -1;

693

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

694

int e = errno;

695

perror("connect");

696

errno = e;

697

}

698

goto mandos_end;

699

}

700

701

if(quit_now){

702

errno = EINTR;

703

goto mandos_end;

636

704

}

637

705

638

706

const char *out = mandos_protocol_version;

642

710

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

643

711

out_size - written));

644

712

if(ret == -1){

713

int e = errno;

645

714

perror("write");

646

retval = -1;

715

errno = e;

647

716

goto mandos_end;

648

717

}

649

718

written += (size_t)ret;

657

726

break;

658

727

}

659

728

}

729

730

if(quit_now){

731

errno = EINTR;

732

goto mandos_end;

733

}

660

734

}

661

735

662

736

if(debug){

663

737

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

664

738

}

665

739

740

if(quit_now){

741

errno = EINTR;

742

goto mandos_end;

743

}

744

666

745

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

667

746

668

do{

747

if(quit_now){

748

errno = EINTR;

749

goto mandos_end;

750

}

751

752

do {

669

753

ret = gnutls_handshake(session);

754

if(quit_now){

755

errno = EINTR;

756

goto mandos_end;

757

}

670

758

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

671

759

672

760

if(ret != GNUTLS_E_SUCCESS){

674

762

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

675

763

gnutls_perror(ret);

676

764

}

677

retval = -1;

765

errno = EPROTO;

678

766

goto mandos_end;

679

767

}

680

768

686

774

}

687

775

688

776

while(true){

777

778

if(quit_now){

779

errno = EINTR;

780

goto mandos_end;

781

}

782

689

783

buffer_capacity = incbuffer(&buffer, buffer_length,

690

784

buffer_capacity);

691

785

if(buffer_capacity == 0){

786

int e = errno;

692

787

perror("incbuffer");

693

retval = -1;

788

errno = e;

789

goto mandos_end;

790

}

791

792

if(quit_now){

793

errno = EINTR;

694

794

goto mandos_end;

695

795

}

696

796

705

805

case GNUTLS_E_AGAIN:

706

806

break;

707

807

case GNUTLS_E_REHANDSHAKE:

708

do{

808

do {

709

809

ret = gnutls_handshake(session);

810

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

710

815

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

711

816

if(ret < 0){

712

817

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

713

818

gnutls_perror(ret);

714

retval = -1;

819

errno = EPROTO;

715

820

goto mandos_end;

716

821

}

717

822

break;

718

823

default:

719

824

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

720

825

" encrypted session with Mandos server\n");

721

retval = -1;

722

826

gnutls_bye(session, GNUTLS_SHUT_RDWR);

827

errno = EIO;

723

828

goto mandos_end;

724

829

}

725

830

} else {

731

836

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

732

837

}

733

838

734

gnutls_bye(session, GNUTLS_SHUT_RDWR);

839

if(quit_now){

840

errno = EINTR;

841

goto mandos_end;

842

}

843

844

do {

845

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

846

if(quit_now){

847

errno = EINTR;

848

goto mandos_end;

849

}

850

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

735

851

736

852

if(buffer_length > 0){

853

ssize_t decrypted_buffer_size;

737

854

decrypted_buffer_size = pgp_packet_decrypt(buffer,

738

855

buffer_length,

739

856

&decrypted_buffer);

740

857

if(decrypted_buffer_size >= 0){

858

741

859

written = 0;

742

860

while(written < (size_t) decrypted_buffer_size){

861

if(quit_now){

862

errno = EINTR;

863

goto mandos_end;

864

}

865

743

866

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

744

867

(size_t)decrypted_buffer_size - written,

745

868

stdout);

746

869

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

870

int e = errno;

747

871

if(debug){

748

872

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

749

873

strerror(errno));

750

874

}

751

retval = -1;

752

break;

875

errno = e;

876

goto mandos_end;

753

877

}

754

878

written += (size_t)ret;

755

879

}

756

free(decrypted_buffer);

757

} else {

758

retval = -1;

880

retval = 0;

759

881

}

760

} else {

761

retval = -1;

762

882

}

763

883

764

884

/* Shutdown procedure */

765

885

766

886

mandos_end:

767

free(buffer);

768

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

769

if(ret == -1){

770

perror("close");

887

{

888

int e = errno;

889

free(decrypted_buffer);

890

free(buffer);

891

if(tcp_sd >= 0){

892

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

893

}

894

if(ret == -1){

895

if(e == 0){

896

e = errno;

897

}

898

perror("close");

899

}

900

gnutls_deinit(session);

901

if(quit_now){

902

e = EINTR;

903

retval = -1;

904

}

905

errno = e;

771

906

}

772

gnutls_deinit(session);

773

907

return retval;

774

908

}

775

909

786

920

AVAHI_GCC_UNUSED AvahiStringList *txt,

787

921

AVAHI_GCC_UNUSED AvahiLookupResultFlags

788

922

flags,

789

__attribute__((unused)) void* userdata){

923

AVAHI_GCC_UNUSED void* userdata){

790

924

assert(r);

791

925

792

926

/* Called whenever a service has been resolved successfully or

793

927

timed out */

794

928

929

if(quit_now){

930

return;

931

}

932

795

933

switch(event){

796

934

default:

797

935

case AVAHI_RESOLVER_FAILURE:

828

966

const char *domain,

829

967

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

968

flags,

831

__attribute__((unused)) void* userdata){

969

AVAHI_GCC_UNUSED void* userdata){

832

970

assert(b);

833

971

834

972

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

835

973

is removed from the LAN */

836

974

975

if(quit_now){

976

return;

977

}

978

837

979

switch(event){

838

980

default:

839

981

case AVAHI_BROWSER_FAILURE:

849

991

the callback function is called the Avahi server will free the

850

992

resolver for us. */

851

993

852

if(!(avahi_s_service_resolver_new(mc.server, interface,

853

protocol, name, type, domain,

854

AVAHI_PROTO_INET6, 0,

855

resolve_callback, NULL)))

994

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

995

name, type, domain, protocol, 0,

996

resolve_callback, NULL) == NULL)

856

997

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

857

998

name, avahi_strerror(avahi_server_errno(mc.server)));

858

999

break;

869

1010

}

870

1011

}

871

1012

872

static void handle_sigterm(__attribute__((unused)) int sig){

1013

/* stop main loop after sigterm has been called */

1014

static void handle_sigterm(int sig){

1015

if(quit_now){

1016

return;

1017

}

1018

quit_now = 1;

1019

signal_received = sig;

873

1020

int old_errno = errno;

874

avahi_simple_poll_quit(mc.simple_poll);

1021

if(mc.simple_poll != NULL){

1022

avahi_simple_poll_quit(mc.simple_poll);

1023

}

875

1024

errno = old_errno;

876

1025

}

877

1026

1027

/*

1028

* This function determines if a directory entry in /sys/class/net

1029

* corresponds to an acceptable network device.

1030

* (This function is passed to scandir(3) as a filter function.)

1031

*/

1032

int good_interface(const struct dirent *if_entry){

1033

ssize_t ssret;

1034

char *flagname = NULL;

1035

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1036

if_entry->d_name);

1037

if(ret < 0){

1038

perror("asprintf");

1039

return 0;

1040

}

1041

if(if_entry->d_name[0] == '.'){

1042

return 0;

1043

}

1044

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1045

if(flags_fd == -1){

1046

perror("open");

1047

return 0;

1048

}

1049

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1050

/* read line from flags_fd */

1051

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1052

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1053

flagstring[(size_t)to_read] = '\0';

1054

if(flagstring == NULL){

1055

perror("malloc");

1056

close(flags_fd);

1057

return 0;

1058

}

1059

while(to_read > 0){

1060

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1061

(size_t)to_read));

1062

if(ssret == -1){

1063

perror("read");

1064

free(flagstring);

1065

close(flags_fd);

1066

return 0;

1067

}

1068

to_read -= ssret;

1069

if(ssret == 0){

1070

break;

1071

}

1072

}

1073

close(flags_fd);

1074

intmax_t tmpmax;

1075

char *tmp;

1076

errno = 0;

1077

tmpmax = strtoimax(flagstring, &tmp, 0);

1078

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1079

and not (isspace(*tmp)))

1080

or tmpmax != (ifreq_flags)tmpmax){

1081

if(debug){

1082

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1083

flagstring, if_entry->d_name);

1084

}

1085

free(flagstring);

1086

return 0;

1087

}

1088

free(flagstring);

1089

ifreq_flags flags = (ifreq_flags)tmpmax;

1090

/* Reject the loopback device */

1091

if(flags & IFF_LOOPBACK){

1092

if(debug){

1093

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1094

if_entry->d_name);

1095

}

1096

return 0;

1097

}

1098

/* Accept point-to-point devices only if connect_to is specified */

1099

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1100

if(debug){

1101

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1102

if_entry->d_name);

1103

}

1104

return 1;

1105

}

1106

/* Otherwise, reject non-broadcast-capable devices */

1107

if(not (flags & IFF_BROADCAST)){

1108

if(debug){

1109

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1110

if_entry->d_name);

1111

}

1112

return 0;

1113

}

1114

/* Accept this device */

1115

if(debug){

1116

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1117

if_entry->d_name);

1118

}

1119

return 1;

1120

}

1121

878

1122

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

879

1123

AvahiSServiceBrowser *sb = NULL;

880

1124

int error;

881

1125

int ret;

882

1126

intmax_t tmpmax;

883

int numchars;

1127

char *tmp;

884

1128

int exitcode = EXIT_SUCCESS;

885

const char *interface = "eth0";

1129

const char *interface = "";

886

1130

struct ifreq network;

887

int sd;

1131

int sd = -1;

1132

bool take_down_interface = false;

888

1133

uid_t uid;

889

1134

gid_t gid;

890

char *connect_to = NULL;

891

1135

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

892

1136

bool tempdir_created = false;

893

1137

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

896

1140

897

1141

bool gnutls_initialized = false;

898

1142

bool gpgme_initialized = false;

899

double delay = 2.5;

900

901

struct sigaction old_sigterm_action;

1143

float delay = 2.5f;

1144

1145

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

902

1146

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

903

904

/* Initialize mandos context */

905

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

906

.dh_bits = 1024, .priority = "SECURE256"

907

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

1147

1148

uid = getuid();

1149

gid = getgid();

1150

1151

/* Lower any group privileges we might have, just to be safe */

1152

errno = 0;

1153

ret = setgid(gid);

1154

if(ret == -1){

1155

perror("setgid");

1156

}

1157

1158

/* Lower user privileges (temporarily) */

1159

errno = 0;

1160

ret = seteuid(uid);

1161

if(ret == -1){

1162

perror("seteuid");

1163

}

1164

1165

if(quit_now){

1166

goto end;

1167

}

908

1168

909

1169

{

910

1170

struct argp_option options[] = {

940

1200

.arg = "SECONDS",

941

1201

.doc = "Maximum delay to wait for interface startup",

942

1202

.group = 2 },

1203

/*

1204

* These reproduce what we would get without ARGP_NO_HELP

1205

*/

1206

{ .name = "help", .key = '?',

1207

.doc = "Give this help list", .group = -1 },

1208

{ .name = "usage", .key = -3,

1209

.doc = "Give a short usage message", .group = -1 },

1210

{ .name = "version", .key = 'V',

1211

.doc = "Print program version", .group = -1 },

943

1212

{ .name = NULL }

944

1213

};

945

1214

946

1215

error_t parse_opt(int key, char *arg,

947

1216

struct argp_state *state){

1217

errno = 0;

948

1218

switch(key){

949

1219

case 128: /* --debug */

950

1220

debug = true;

962

1232

pubkey = arg;

963

1233

break;

964

1234

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

965

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

966

if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax

967

or arg[numchars] != '\0'){

968

fprintf(stderr, "Bad number of DH bits\n");

969

exit(EXIT_FAILURE);

1235

errno = 0;

1236

tmpmax = strtoimax(arg, &tmp, 10);

1237

if(errno != 0 or tmp == arg or *tmp != '\0'

1238

or tmpmax != (typeof(mc.dh_bits))tmpmax){

1239

argp_error(state, "Bad number of DH bits");

970

1240

}

971

1241

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

972

1242

break;

974

1244

mc.priority = arg;

975

1245

break;

976

1246

case 131: /* --delay */

977

ret = sscanf(arg, "%lf%n", &delay, &numchars);

978

if(ret < 1 or arg[numchars] != '\0'){

979

fprintf(stderr, "Bad delay\n");

980

exit(EXIT_FAILURE);

1247

errno = 0;

1248

delay = strtof(arg, &tmp);

1249

if(errno != 0 or tmp == arg or *tmp != '\0'){

1250

argp_error(state, "Bad delay");

981

1251

}

982

1252

break;

983

case ARGP_KEY_ARG:

984

argp_usage(state);

985

case ARGP_KEY_END:

1253

/*

1254

* These reproduce what we would get without ARGP_NO_HELP

1255

*/

1256

case '?': /* --help */

1257

argp_state_help(state, state->out_stream,

1258

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1259

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1260

case -3: /* --usage */

1261

argp_state_help(state, state->out_stream,

1262

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1263

case 'V': /* --version */

1264

fprintf(state->out_stream, "%s\n", argp_program_version);

1265

exit(argp_err_exit_status);

986

1266

break;

987

1267

default:

988

1268

return ARGP_ERR_UNKNOWN;

989

1269

}

990

return 0;

1270

return errno;

991

1271

}

992

1272

993

1273

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

994

1274

.args_doc = "",

995

1275

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

996

1276

" passwords from a Mandos server" };

997

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

998

if(ret == ARGP_ERR_UNKNOWN){

999

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

1277

ret = argp_parse(&argp, argc, argv,

1278

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1279

switch(ret){

1280

case 0:

1281

break;

1282

case ENOMEM:

1283

default:

1284

errno = ret;

1285

perror("argp_parse");

1286

exitcode = EX_OSERR;

1287

goto end;

1288

case EINVAL:

1289

exitcode = EX_USAGE;

1290

goto end;

1291

}

1292

}

1293

1294

if(not debug){

1295

avahi_set_log_function(empty_log);

1296

}

1297

1298

if(interface[0] == '\0'){

1299

struct dirent **direntries;

1300

ret = scandir(sys_class_net, &direntries, good_interface,

1301

alphasort);

1302

if(ret >= 1){

1303

/* Pick the first good interface */

1304

interface = strdup(direntries[0]->d_name);

1305

if(debug){

1306

fprintf(stderr, "Using interface \"%s\"\n", interface);

1307

}

1308

if(interface == NULL){

1309

perror("malloc");

1310

free(direntries);

1311

exitcode = EXIT_FAILURE;

1312

goto end;

1313

}

1314

free(direntries);

1315

} else {

1316

free(direntries);

1317

fprintf(stderr, "Could not find a network interface\n");

1000

1318

exitcode = EXIT_FAILURE;

1001

1319

goto end;

1002

1320

}

1003

1321

}

1004

1322

1323

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1324

from the signal handler */

1325

/* Initialize the pseudo-RNG for Avahi */

1326

srand((unsigned int) time(NULL));

1327

mc.simple_poll = avahi_simple_poll_new();

1328

if(mc.simple_poll == NULL){

1329

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1330

exitcode = EX_UNAVAILABLE;

1331

goto end;

1332

}

1333

1334

sigemptyset(&sigterm_action.sa_mask);

1335

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1336

if(ret == -1){

1337

perror("sigaddset");

1338

exitcode = EX_OSERR;

1339

goto end;

1340

}

1341

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1342

if(ret == -1){

1343

perror("sigaddset");

1344

exitcode = EX_OSERR;

1345

goto end;

1346

}

1347

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1348

if(ret == -1){

1349

perror("sigaddset");

1350

exitcode = EX_OSERR;

1351

goto end;

1352

}

1353

/* Need to check if the handler is SIG_IGN before handling:

1354

| [[info:libc:Initial Signal Actions]] |

1355

| [[info:libc:Basic Signal Handling]] |

1356

*/

1357

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1358

if(ret == -1){

1359

perror("sigaction");

1360

return EX_OSERR;

1361

}

1362

if(old_sigterm_action.sa_handler != SIG_IGN){

1363

ret = sigaction(SIGINT, &sigterm_action, NULL);

1364

if(ret == -1){

1365

perror("sigaction");

1366

exitcode = EX_OSERR;

1367

goto end;

1368

}

1369

}

1370

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1371

if(ret == -1){

1372

perror("sigaction");

1373

return EX_OSERR;

1374

}

1375

if(old_sigterm_action.sa_handler != SIG_IGN){

1376

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1377

if(ret == -1){

1378

perror("sigaction");

1379

exitcode = EX_OSERR;

1380

goto end;

1381

}

1382

}

1383

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1384

if(ret == -1){

1385

perror("sigaction");

1386

return EX_OSERR;

1387

}

1388

if(old_sigterm_action.sa_handler != SIG_IGN){

1389

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1390

if(ret == -1){

1391

perror("sigaction");

1392

exitcode = EX_OSERR;

1393

goto end;

1394

}

1395

}

1396

1005

1397

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

1006

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

1398

if(strcmp(interface, "none") != 0){

1399

if_index = (AvahiIfIndex) if_nametoindex(interface);

1400

if(if_index == 0){

1401

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

1402

exitcode = EX_UNAVAILABLE;

1403

goto end;

1404

}

1405

1406

if(quit_now){

1407

goto end;

1408

}

1409

1410

/* Re-raise priviliges */

1411

errno = 0;

1412

ret = seteuid(0);

1413

if(ret == -1){

1414

perror("seteuid");

1415

}

1416

1007

1417

#ifdef __linux__

1008

1418

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1009

messages to mess up the prompt */

1419

messages about the network interface to mess up the prompt */

1010

1420

ret = klogctl(8, NULL, 5);

1011

1421

bool restore_loglevel = true;

1012

1422

if(ret == -1){

1013

1423

restore_loglevel = false;

1014

1424

perror("klogctl");

1015

1425

}

1016

#endif

1426

#endif /* __linux__ */

1017

1427

1018

1428

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1019

1429

if(sd < 0){

1020

1430

perror("socket");

1021

exitcode = EXIT_FAILURE;

1431

exitcode = EX_OSERR;

1022

1432

#ifdef __linux__

1023

1433

if(restore_loglevel){

1024

1434

ret = klogctl(7, NULL, 0);

1026

1436

perror("klogctl");

1027

1437

}

1028

1438

}

1029

#endif

1439

#endif /* __linux__ */

1440

/* Lower privileges */

1441

errno = 0;

1442

ret = seteuid(uid);

1443

if(ret == -1){

1444

perror("seteuid");

1445

}

1030

1446

goto end;

1031

1447

}

1032

1448

strcpy(network.ifr_name, interface);

1040

1456

perror("klogctl");

1041

1457

}

1042

1458

}

1043

#endif

1044

exitcode = EXIT_FAILURE;

1459

#endif /* __linux__ */

1460

exitcode = EX_OSERR;

1461

/* Lower privileges */

1462

errno = 0;

1463

ret = seteuid(uid);

1464

if(ret == -1){

1465

perror("seteuid");

1466

}

1045

1467

goto end;

1046

1468

}

1047

1469

if((network.ifr_flags & IFF_UP) == 0){

1048

1470

network.ifr_flags |= IFF_UP;

1471

take_down_interface = true;

1049

1472

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1050

1473

if(ret == -1){

1051

perror("ioctl SIOCSIFFLAGS");

1052

exitcode = EXIT_FAILURE;

1474

take_down_interface = false;

1475

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1476

exitcode = EX_OSERR;

1053

1477

#ifdef __linux__

1054

1478

if(restore_loglevel){

1055

1479

ret = klogctl(7, NULL, 0);

1057

1481

perror("klogctl");

1058

1482

}

1059

1483

}

1060

#endif

1484

#endif /* __linux__ */

1485

/* Lower privileges */

1486

errno = 0;

1487

ret = seteuid(uid);

1488

if(ret == -1){

1489

perror("seteuid");

1490

}

1061

1491

goto end;

1062

1492

}

1063

1493

}

1075

1505

perror("nanosleep");

1076

1506

}

1077

1507

}

1078

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1079

if(ret == -1){

1080

perror("close");

1508

if(not take_down_interface){

1509

/* We won't need the socket anymore */

1510

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1511

if(ret == -1){

1512

perror("close");

1513

}

1081

1514

}

1082

1515

#ifdef __linux__

1083

1516

if(restore_loglevel){

1087

1520

perror("klogctl");

1088

1521

}

1089

1522

}

1090

#endif

1091

}

1092

1093

uid = getuid();

1094

gid = getgid();

1095

1096

errno = 0;

1097

setgid(gid);

1098

if(ret == -1){

1099

perror("setgid");

1100

}

1101

1102

ret = setuid(uid);

1103

if(ret == -1){

1104

perror("setuid");

1523

#endif /* __linux__ */

1524

/* Lower privileges */

1525

errno = 0;

1526

if(take_down_interface){

1527

/* Lower privileges */

1528

ret = seteuid(uid);

1529

if(ret == -1){

1530

perror("seteuid");

1531

}

1532

} else {

1533

/* Lower privileges permanently */

1534

ret = setuid(uid);

1535

if(ret == -1){

1536

perror("setuid");

1537

}

1538

}

1539

}

1540

1541

if(quit_now){

1542

goto end;

1105

1543

}

1106

1544

1107

1545

ret = init_gnutls_global(pubkey, seckey);

1108

1546

if(ret == -1){

1109

1547

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

1110

exitcode = EXIT_FAILURE;

1548

exitcode = EX_UNAVAILABLE;

1111

1549

goto end;

1112

1550

} else {

1113

1551

gnutls_initialized = true;

1114

1552

}

1115

1553

1554

if(quit_now){

1555

goto end;

1556

}

1557

1558

tempdir_created = true;

1116

1559

if(mkdtemp(tempdir) == NULL){

1560

tempdir_created = false;

1117

1561

perror("mkdtemp");

1118

1562

goto end;

1119

1563

}

1120

tempdir_created = true;

1564

1565

if(quit_now){

1566

goto end;

1567

}

1121

1568

1122

1569

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

1123

1570

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

1124

exitcode = EXIT_FAILURE;

1571

exitcode = EX_UNAVAILABLE;

1125

1572

goto end;

1126

1573

} else {

1127

1574

gpgme_initialized = true;

1128

1575

}

1129

1576

1130

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

1131

if_index = (AvahiIfIndex) if_nametoindex(interface);

1132

if(if_index == 0){

1133

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

1134

exitcode = EXIT_FAILURE;

1135

goto end;

1136

}

1577

if(quit_now){

1578

goto end;

1137

1579

}

1138

1580

1139

1581

if(connect_to != NULL){

1142

1584

char *address = strrchr(connect_to, ':');

1143

1585

if(address == NULL){

1144

1586

fprintf(stderr, "No colon in address\n");

1145

exitcode = EXIT_FAILURE;

1146

goto end;

1147

}

1587

exitcode = EX_USAGE;

1588

goto end;

1589

}

1590

1591

if(quit_now){

1592

goto end;

1593

}

1594

1148

1595

uint16_t port;

1149

ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);

1150

if(ret < 1 or tmpmax != (uint16_t)tmpmax

1151

or address[numchars+1] != '\0'){

1596

errno = 0;

1597

tmpmax = strtoimax(address+1, &tmp, 10);

1598

if(errno != 0 or tmp == address+1 or *tmp != '\0'

1599

or tmpmax != (uint16_t)tmpmax){

1152

1600

fprintf(stderr, "Bad port number\n");

1153

exitcode = EXIT_FAILURE;

1154

goto end;

1155

}

1601

exitcode = EX_USAGE;

1602

goto end;

1603

}

1604

1605

if(quit_now){

1606

goto end;

1607

}

1608

1156

1609

port = (uint16_t)tmpmax;

1157

1610

*address = '\0';

1158

1611

address = connect_to;

1163

1616

} else {

1164

1617

af = AF_INET;

1165

1618

}

1166

ret = start_mandos_communication(address, port, if_index,

1167

af);

1168

if(ret < 0){

1169

exitcode = EXIT_FAILURE;

1170

} else {

1619

1620

if(quit_now){

1621

goto end;

1622

}

1623

1624

while(not quit_now){

1625

ret = start_mandos_communication(address, port, if_index, af);

1626

if(quit_now or ret == 0){

1627

break;

1628

}

1629

sleep(15);

1630

};

1631

1632

if (not quit_now){

1171

1633

exitcode = EXIT_SUCCESS;

1172

1634

}

1635

1173

1636

goto end;

1174

1637

}

1175

1638

1176

if(not debug){

1177

avahi_set_log_function(empty_log);

1178

}

1179

1180

/* Initialize the pseudo-RNG for Avahi */

1181

srand((unsigned int) time(NULL));

1182

1183

/* Allocate main Avahi loop object */

1184

mc.simple_poll = avahi_simple_poll_new();

1185

if(mc.simple_poll == NULL){

1186

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1187

exitcode = EXIT_FAILURE;

1639

if(quit_now){

1188

1640

goto end;

1189

1641

}

1190

1642

1210

1662

if(mc.server == NULL){

1211

1663

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

1212

1664

avahi_strerror(error));

1213

exitcode = EXIT_FAILURE;

1665

exitcode = EX_UNAVAILABLE;

1666

goto end;

1667

}

1668

1669

if(quit_now){

1214

1670

goto end;

1215

1671

}

1216

1672

1217

1673

/* Create the Avahi service browser */

1218

1674

sb = avahi_s_service_browser_new(mc.server, if_index,

1219

AVAHI_PROTO_INET6, "_mandos._tcp",

1675

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1220

1676

NULL, 0, browse_callback, NULL);

1221

1677

if(sb == NULL){

1222

1678

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

1223

1679

avahi_strerror(avahi_server_errno(mc.server)));

1224

exitcode = EXIT_FAILURE;

1225

goto end;

1226

}

1227

1228

sigemptyset(&sigterm_action.sa_mask);

1229

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1230

if(ret == -1){

1231

perror("sigaddset");

1232

exitcode = EXIT_FAILURE;

1233

goto end;

1234

}

1235

ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);

1236

if(ret == -1){

1237

perror("sigaction");

1238

exitcode = EXIT_FAILURE;

1239

goto end;

1240

}

1680

exitcode = EX_UNAVAILABLE;

1681

goto end;

1682

}

1683

1684

if(quit_now){

1685

goto end;

1686

}

1241

1687

1242

1688

/* Run the main loop */

1243

1689

1273

1719

gpgme_release(mc.ctx);

1274

1720

}

1275

1721

1722

/* Take down the network interface */

1723

if(take_down_interface){

1724

/* Re-raise priviliges */

1725

errno = 0;

1726

ret = seteuid(0);

1727

if(ret == -1){

1728

perror("seteuid");

1729

}

1730

if(geteuid() == 0){

1731

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1732

if(ret == -1){

1733

perror("ioctl SIOCGIFFLAGS");

1734

} else if(network.ifr_flags & IFF_UP) {

1735

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

1736

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1737

if(ret == -1){

1738

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1739

}

1740

}

1741

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1742

if(ret == -1){

1743

perror("close");

1744

}

1745

/* Lower privileges permanently */

1746

errno = 0;

1747

ret = setuid(uid);

1748

if(ret == -1){

1749

perror("setuid");

1750

}

1751

}

1752

}

1753

1276

1754

/* Removes the temp directory used by GPGME */

1277

1755

if(tempdir_created){

1278

1756

DIR *d;

1317

1795

}

1318

1796

}

1319

1797

1798

if(quit_now){

1799

sigemptyset(&old_sigterm_action.sa_mask);

1800

old_sigterm_action.sa_handler = SIG_DFL;

1801

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1802

&old_sigterm_action,

1803

NULL));

1804

if(ret == -1){

1805

perror("sigaction");

1806

}

1807

do {

1808

ret = raise(signal_received);

1809

} while(ret != 0 and errno == EINTR);

1810

if(ret != 0){

1811

perror("raise");

1812

abort();

1813

}

1814

TEMP_FAILURE_RETRY(pause());

1815

}

1816

1320

1817

return exitcode;

1321

1818

}