/mandos/release : revision 237.7.29

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

76

80

argp_parse(), ARGP_KEY_ARG,

77

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

78

82

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

79

sigaction(), SIGTERM, sigaction */

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 */

80

87

81

88

#ifdef __linux__

82

89

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

83

#endif

90

#endif /* __linux__ */

84

91

85

92

/* Avahi */

86

93

/* All Avahi types, constants and functions

120

127

static const char mandos_protocol_version[] = "1";

121

128

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

122

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;

123

132

124

133

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

125

134

typedef struct {

133

142

} mandos_context;

134

143

135

144

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

136

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;

137

151

138

152

/*

139

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

140

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

141

* 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.

142

156

*/

143

157

size_t incbuffer(char **buffer, size_t buffer_length,

144

158

size_t buffer_capacity){

157

171

*/

158

172

static bool init_gpgme(const char *seckey,

159

173

const char *pubkey, const char *tempdir){

160

int ret;

161

174

gpgme_error_t rc;

162

175

gpgme_engine_info_t engine_info;

163

176

166

179

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

167

180

*/

168

181

bool import_key(const char *filename){

182

int ret;

169

183

int fd;

170

184

gpgme_data_t pgp_data;

171

185

242

256

return false;

243

257

}

244

258

245

return true;

259

return true;

246

260

}

247

261

248

262

/*

302

316

}

303

317

gpgme_recipient_t recipient;

304

318

recipient = result->recipients;

305

if(recipient){

306

while(recipient != NULL){

307

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

308

gpgme_pubkey_algo_name(recipient->pubkey_algo));

309

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

310

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

311

recipient->status == GPG_ERR_NO_SECKEY

312

? "No" : "Yes");

313

recipient = recipient->next;

314

}

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;

315

327

}

316

328

}

317

329

}

469

481

static int init_gnutls_session(gnutls_session_t *session){

470

482

int ret;

471

483

/* GnuTLS session creation */

472

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);

473

490

if(ret != GNUTLS_E_SUCCESS){

474

491

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

475

492

safer_gnutls_strerror(ret));

477

494

478

495

{

479

496

const char *err;

480

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);

481

504

if(ret != GNUTLS_E_SUCCESS){

482

505

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

483

506

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

487

510

}

488

511

}

489

512

490

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

491

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);

492

521

if(ret != GNUTLS_E_SUCCESS){

493

522

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

494

523

safer_gnutls_strerror(ret));

497

526

}

498

527

499

528

/* ignore client certificate if any. */

500

gnutls_certificate_server_set_request(*session,

501

GNUTLS_CERT_IGNORE);

529

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

502

530

503

531

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

504

532

513

541

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

514

542

AvahiIfIndex if_index,

515

543

int af){

516

int ret, tcp_sd;

544

int ret, tcp_sd = -1;

517

545

ssize_t sret;

518

546

union {

519

547

struct sockaddr_in in;

520

548

struct sockaddr_in6 in6;

521

549

} to;

522

550

char *buffer = NULL;

523

char *decrypted_buffer;

551

char *decrypted_buffer = NULL;

524

552

size_t buffer_length = 0;

525

553

size_t buffer_capacity = 0;

526

ssize_t decrypted_buffer_size;

527

554

size_t written;

528

int retval = 0;

555

int retval = -1;

529

556

gnutls_session_t session;

530

557

int pf; /* Protocol family */

531

558

559

errno = 0;

560

561

if(quit_now){

562

errno = EINTR;

563

return -1;

564

}

565

532

566

switch(af){

533

567

case AF_INET6:

534

568

pf = PF_INET6;

538

572

break;

539

573

default:

540

574

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

575

errno = EINVAL;

541

576

return -1;

542

577

}

543

578

553

588

554

589

tcp_sd = socket(pf, SOCK_STREAM, 0);

555

590

if(tcp_sd < 0){

591

int e = errno;

556

592

perror("socket");

557

return -1;

593

errno = e;

594

goto mandos_end;

595

}

596

597

if(quit_now){

598

errno = EINTR;

599

goto mandos_end;

558

600

}

559

601

560

602

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

561

603

if(af == AF_INET6){

562

to.in6.sin6_family = (uint16_t)af;

604

to.in6.sin6_family = (sa_family_t)af;

563

605

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

564

606

} else { /* IPv4 */

565

607

to.in.sin_family = (sa_family_t)af;

566

608

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

567

609

}

568

610

if(ret < 0 ){

611

int e = errno;

569

612

perror("inet_pton");

570

return -1;

613

errno = e;

614

goto mandos_end;

571

615

}

572

616

if(ret == 0){

617

int e = errno;

573

618

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

574

return -1;

619

errno = e;

620

goto mandos_end;

575

621

}

576

622

if(af == AF_INET6){

577

623

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

584

630

if(if_index == AVAHI_IF_UNSPEC){

585

631

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

586

632

" without a network interface\n");

587

return -1;

633

errno = EINVAL;

634

goto mandos_end;

588

635

}

589

636

/* Set the network interface number as scope */

590

637

to.in6.sin6_scope_id = (uint32_t)if_index;

595

642

-Wunreachable-code */

596

643

}

597

644

645

if(quit_now){

646

errno = EINTR;

647

goto mandos_end;

648

}

649

598

650

if(debug){

599

651

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

600

652

char interface[IF_NAMESIZE];

627

679

}

628

680

}

629

681

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

630

687

if(af == AF_INET6){

631

688

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

632

689

} else {

633

690

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

634

691

}

635

692

if(ret < 0){

636

perror("connect");

637

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;

638

704

}

639

705

640

706

const char *out = mandos_protocol_version;

644

710

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

645

711

out_size - written));

646

712

if(ret == -1){

713

int e = errno;

647

714

perror("write");

648

retval = -1;

715

errno = e;

649

716

goto mandos_end;

650

717

}

651

718

written += (size_t)ret;

659

726

break;

660

727

}

661

728

}

729

730

if(quit_now){

731

errno = EINTR;

732

goto mandos_end;

733

}

662

734

}

663

735

664

736

if(debug){

665

737

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

666

738

}

667

739

740

if(quit_now){

741

errno = EINTR;

742

goto mandos_end;

743

}

744

668

745

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

669

746

670

do{

747

if(quit_now){

748

errno = EINTR;

749

goto mandos_end;

750

}

751

752

do {

671

753

ret = gnutls_handshake(session);

754

if(quit_now){

755

errno = EINTR;

756

goto mandos_end;

757

}

672

758

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

673

759

674

760

if(ret != GNUTLS_E_SUCCESS){

676

762

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

677

763

gnutls_perror(ret);

678

764

}

679

retval = -1;

765

errno = EPROTO;

680

766

goto mandos_end;

681

767

}

682

768

688

774

}

689

775

690

776

while(true){

777

778

if(quit_now){

779

errno = EINTR;

780

goto mandos_end;

781

}

782

691

783

buffer_capacity = incbuffer(&buffer, buffer_length,

692

784

buffer_capacity);

693

785

if(buffer_capacity == 0){

786

int e = errno;

694

787

perror("incbuffer");

695

retval = -1;

788

errno = e;

789

goto mandos_end;

790

}

791

792

if(quit_now){

793

errno = EINTR;

696

794

goto mandos_end;

697

795

}

698

796

707

805

case GNUTLS_E_AGAIN:

708

806

break;

709

807

case GNUTLS_E_REHANDSHAKE:

710

do{

808

do {

711

809

ret = gnutls_handshake(session);

810

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

712

815

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

713

816

if(ret < 0){

714

817

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

715

818

gnutls_perror(ret);

716

retval = -1;

819

errno = EPROTO;

717

820

goto mandos_end;

718

821

}

719

822

break;

720

823

default:

721

824

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

722

825

" encrypted session with Mandos server\n");

723

retval = -1;

724

826

gnutls_bye(session, GNUTLS_SHUT_RDWR);

827

errno = EIO;

725

828

goto mandos_end;

726

829

}

727

830

} else {

733

836

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

734

837

}

735

838

736

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);

737

851

738

852

if(buffer_length > 0){

853

ssize_t decrypted_buffer_size;

739

854

decrypted_buffer_size = pgp_packet_decrypt(buffer,

740

855

buffer_length,

741

856

&decrypted_buffer);

742

857

if(decrypted_buffer_size >= 0){

858

743

859

written = 0;

744

860

while(written < (size_t) decrypted_buffer_size){

861

if(quit_now){

862

errno = EINTR;

863

goto mandos_end;

864

}

865

745

866

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

746

867

(size_t)decrypted_buffer_size - written,

747

868

stdout);

748

869

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

870

int e = errno;

749

871

if(debug){

750

872

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

751

873

strerror(errno));

752

874

}

753

retval = -1;

754

break;

875

errno = e;

876

goto mandos_end;

755

877

}

756

878

written += (size_t)ret;

757

879

}

758

free(decrypted_buffer);

759

} else {

760

retval = -1;

880

retval = 0;

761

881

}

762

} else {

763

retval = -1;

764

882

}

765

883

766

884

/* Shutdown procedure */

767

885

768

886

mandos_end:

769

free(buffer);

770

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

771

if(ret == -1){

772

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;

773

906

}

774

gnutls_deinit(session);

775

907

return retval;

776

908

}

777

909

794

926

/* Called whenever a service has been resolved successfully or

795

927

timed out */

796

928

929

if(quit_now){

930

return;

931

}

932

797

933

switch(event){

798

934

default:

799

935

case AVAHI_RESOLVER_FAILURE:

836

972

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

837

973

is removed from the LAN */

838

974

975

if(quit_now){

976

return;

977

}

978

839

979

switch(event){

840

980

default:

841

981

case AVAHI_BROWSER_FAILURE:

851

991

the callback function is called the Avahi server will free the

852

992

resolver for us. */

853

993

854

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

855

protocol, name, type, domain,

856

AVAHI_PROTO_INET6, 0,

857

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)

858

997

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

859

998

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

860

999

break;

871

1010

}

872

1011

}

873

1012

874

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;

875

1020

int old_errno = errno;

876

avahi_simple_poll_quit(mc.simple_poll);

1021

if(mc.simple_poll != NULL){

1022

avahi_simple_poll_quit(mc.simple_poll);

1023

}

877

1024

errno = old_errno;

878

1025

}

879

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

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

1036

return 0;

1037

}

1038

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

1039

if_entry->d_name);

1040

if(ret < 0){

1041

perror("asprintf");

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

free(flagname);

1048

return 0;

1049

}

1050

free(flagname);

1051

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

1052

/* read line from flags_fd */

1053

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

1054

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

1055

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

1056

if(flagstring == NULL){

1057

perror("malloc");

1058

close(flags_fd);

1059

return 0;

1060

}

1061

while(to_read > 0){

1062

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

1063

(size_t)to_read));

1064

if(ssret == -1){

1065

perror("read");

1066

free(flagstring);

1067

close(flags_fd);

1068

return 0;

1069

}

1070

to_read -= ssret;

1071

if(ssret == 0){

1072

break;

1073

}

1074

}

1075

close(flags_fd);

1076

intmax_t tmpmax;

1077

char *tmp;

1078

errno = 0;

1079

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

1080

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

1081

and not (isspace(*tmp)))

1082

or tmpmax != (ifreq_flags)tmpmax){

1083

if(debug){

1084

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

1085

flagstring, if_entry->d_name);

1086

}

1087

free(flagstring);

1088

return 0;

1089

}

1090

free(flagstring);

1091

ifreq_flags flags = (ifreq_flags)tmpmax;

1092

/* Reject the loopback device */

1093

if(flags & IFF_LOOPBACK){

1094

if(debug){

1095

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

1096

if_entry->d_name);

1097

}

1098

return 0;

1099

}

1100

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

1101

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

1102

if(debug){

1103

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

1104

if_entry->d_name);

1105

}

1106

return 1;

1107

}

1108

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

1109

if(not (flags & IFF_BROADCAST)){

1110

if(debug){

1111

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

1112

if_entry->d_name);

1113

}

1114

return 0;

1115

}

1116

/* Reject non-ARP interfaces (including dummy interfaces) */

1117

if(flags & IFF_NOARP){

1118

if(debug){

1119

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

1120

if_entry->d_name);

1121

}

1122

return 0;

1123

}

1124

/* Accept this device */

1125

if(debug){

1126

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

1127

if_entry->d_name);

1128

}

1129

return 1;

1130

}

1131

880

1132

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

881

1133

AvahiSServiceBrowser *sb = NULL;

882

1134

int error;

883

1135

int ret;

884

1136

intmax_t tmpmax;

885

int numchars;

1137

char *tmp;

886

1138

int exitcode = EXIT_SUCCESS;

887

const char *interface = "eth0";

1139

const char *interface = "";

888

1140

struct ifreq network;

889

int sd;

1141

int sd = -1;

1142

bool take_down_interface = false;

890

1143

uid_t uid;

891

1144

gid_t gid;

892

char *connect_to = NULL;

893

1145

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

894

1146

bool tempdir_created = false;

895

1147

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

896

1148

const char *seckey = PATHDIR "/" SECKEY;

897

1149

const char *pubkey = PATHDIR "/" PUBKEY;

898

1150

899

/* Initialize Mandos context */

900

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

901

.dh_bits = 1024, .priority = "SECURE256"

902

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

903

1151

bool gnutls_initialized = false;

904

1152

bool gpgme_initialized = false;

905

double delay = 2.5;

906

907

struct sigaction old_sigterm_action;

1153

float delay = 2.5f;

1154

1155

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

908

1156

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

909

1157

1158

uid = getuid();

1159

gid = getgid();

1160

1161

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

1162

errno = 0;

1163

ret = setgid(gid);

1164

if(ret == -1){

1165

perror("setgid");

1166

}

1167

1168

/* Lower user privileges (temporarily) */

1169

errno = 0;

1170

ret = seteuid(uid);

1171

if(ret == -1){

1172

perror("seteuid");

1173

}

1174

1175

if(quit_now){

1176

goto end;

1177

}

1178

910

1179

{

911

1180

struct argp_option options[] = {

912

1181

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

941

1210

.arg = "SECONDS",

942

1211

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

943

1212

.group = 2 },

1213

/*

1214

* These reproduce what we would get without ARGP_NO_HELP

1215

*/

1216

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

1217

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

1218

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

1219

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

1220

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

1221

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

944

1222

{ .name = NULL }

945

1223

};

946

1224

947

1225

error_t parse_opt(int key, char *arg,

948

1226

struct argp_state *state){

1227

errno = 0;

949

1228

switch(key){

950

1229

case 128: /* --debug */

951

1230

debug = true;

963

1242

pubkey = arg;

964

1243

break;

965

1244

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

966

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

967

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

968

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

969

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

970

exit(EXIT_FAILURE);

1245

errno = 0;

1246

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

1247

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

1248

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

1249

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

971

1250

}

972

1251

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

973

1252

break;

975

1254

mc.priority = arg;

976

1255

break;

977

1256

case 131: /* --delay */

978

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

979

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

980

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

981

exit(EXIT_FAILURE);

1257

errno = 0;

1258

delay = strtof(arg, &tmp);

1259

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

1260

argp_error(state, "Bad delay");

982

1261

}

983

1262

break;

984

case ARGP_KEY_ARG:

985

argp_usage(state);

986

case ARGP_KEY_END:

1263

/*

1264

* These reproduce what we would get without ARGP_NO_HELP

1265

*/

1266

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

1267

argp_state_help(state, state->out_stream,

1268

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1269

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1270

case -3: /* --usage */

1271

argp_state_help(state, state->out_stream,

1272

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1273

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

1274

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

1275

exit(argp_err_exit_status);

987

1276

break;

988

1277

default:

989

1278

return ARGP_ERR_UNKNOWN;

990

1279

}

991

return 0;

1280

return errno;

992

1281

}

993

1282

994

1283

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

995

1284

.args_doc = "",

996

1285

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

997

1286

" passwords from a Mandos server" };

998

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

999

if(ret == ARGP_ERR_UNKNOWN){

1000

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

1287

ret = argp_parse(&argp, argc, argv,

1288

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1289

switch(ret){

1290

case 0:

1291

break;

1292

case ENOMEM:

1293

default:

1294

errno = ret;

1295

perror("argp_parse");

1296

exitcode = EX_OSERR;

1297

goto end;

1298

case EINVAL:

1299

exitcode = EX_USAGE;

1300

goto end;

1301

}

1302

}

1303

1304

if(not debug){

1305

avahi_set_log_function(empty_log);

1306

}

1307

1308

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

1309

struct dirent **direntries;

1310

ret = scandir(sys_class_net, &direntries, good_interface,

1311

alphasort);

1312

if(ret >= 1){

1313

/* Pick the first good interface */

1314

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

1315

if(debug){

1316

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

1317

}

1318

if(interface == NULL){

1319

perror("malloc");

1320

free(direntries);

1321

exitcode = EXIT_FAILURE;

1322

goto end;

1323

}

1324

free(direntries);

1325

} else {

1326

free(direntries);

1327

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

1001

1328

exitcode = EXIT_FAILURE;

1002

1329

goto end;

1003

1330

}

1004

1331

}

1005

1332

1333

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

1334

from the signal handler */

1335

/* Initialize the pseudo-RNG for Avahi */

1336

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

1337

mc.simple_poll = avahi_simple_poll_new();

1338

if(mc.simple_poll == NULL){

1339

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

1340

exitcode = EX_UNAVAILABLE;

1341

goto end;

1342

}

1343

1344

sigemptyset(&sigterm_action.sa_mask);

1345

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

1346

if(ret == -1){

1347

perror("sigaddset");

1348

exitcode = EX_OSERR;

1349

goto end;

1350

}

1351

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

1352

if(ret == -1){

1353

perror("sigaddset");

1354

exitcode = EX_OSERR;

1355

goto end;

1356

}

1357

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

1358

if(ret == -1){

1359

perror("sigaddset");

1360

exitcode = EX_OSERR;

1361

goto end;

1362

}

1363

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

1364

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

1365

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

1366

*/

1367

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

1368

if(ret == -1){

1369

perror("sigaction");

1370

return EX_OSERR;

1371

}

1372

if(old_sigterm_action.sa_handler != SIG_IGN){

1373

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

1374

if(ret == -1){

1375

perror("sigaction");

1376

exitcode = EX_OSERR;

1377

goto end;

1378

}

1379

}

1380

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

1381

if(ret == -1){

1382

perror("sigaction");

1383

return EX_OSERR;

1384

}

1385

if(old_sigterm_action.sa_handler != SIG_IGN){

1386

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

1387

if(ret == -1){

1388

perror("sigaction");

1389

exitcode = EX_OSERR;

1390

goto end;

1391

}

1392

}

1393

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

1394

if(ret == -1){

1395

perror("sigaction");

1396

return EX_OSERR;

1397

}

1398

if(old_sigterm_action.sa_handler != SIG_IGN){

1399

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

1400

if(ret == -1){

1401

perror("sigaction");

1402

exitcode = EX_OSERR;

1403

goto end;

1404

}

1405

}

1406

1006

1407

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

1007

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

1408

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

1409

if_index = (AvahiIfIndex) if_nametoindex(interface);

1410

if(if_index == 0){

1411

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

1412

exitcode = EX_UNAVAILABLE;

1413

goto end;

1414

}

1415

1416

if(quit_now){

1417

goto end;

1418

}

1419

1420

/* Re-raise priviliges */

1421

errno = 0;

1422

ret = seteuid(0);

1423

if(ret == -1){

1424

perror("seteuid");

1425

}

1426

1008

1427

#ifdef __linux__

1009

1428

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1010

messages to mess up the prompt */

1429

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

1011

1430

ret = klogctl(8, NULL, 5);

1012

1431

bool restore_loglevel = true;

1013

1432

if(ret == -1){

1014

1433

restore_loglevel = false;

1015

1434

perror("klogctl");

1016

1435

}

1017

#endif

1436

#endif /* __linux__ */

1018

1437

1019

1438

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1020

1439

if(sd < 0){

1021

1440

perror("socket");

1022

exitcode = EXIT_FAILURE;

1441

exitcode = EX_OSERR;

1023

1442

#ifdef __linux__

1024

1443

if(restore_loglevel){

1025

1444

ret = klogctl(7, NULL, 0);

1027

1446

perror("klogctl");

1028

1447

}

1029

1448

}

1030

#endif

1449

#endif /* __linux__ */

1450

/* Lower privileges */

1451

errno = 0;

1452

ret = seteuid(uid);

1453

if(ret == -1){

1454

perror("seteuid");

1455

}

1031

1456

goto end;

1032

1457

}

1033

1458

strcpy(network.ifr_name, interface);

1041

1466

perror("klogctl");

1042

1467

}

1043

1468

}

1044

#endif

1045

exitcode = EXIT_FAILURE;

1469

#endif /* __linux__ */

1470

exitcode = EX_OSERR;

1471

/* Lower privileges */

1472

errno = 0;

1473

ret = seteuid(uid);

1474

if(ret == -1){

1475

perror("seteuid");

1476

}

1046

1477

goto end;

1047

1478

}

1048

1479

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

1049

1480

network.ifr_flags |= IFF_UP;

1481

take_down_interface = true;

1050

1482

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

1051

1483

if(ret == -1){

1052

perror("ioctl SIOCSIFFLAGS");

1053

exitcode = EXIT_FAILURE;

1484

take_down_interface = false;

1485

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1486

exitcode = EX_OSERR;

1054

1487

#ifdef __linux__

1055

1488

if(restore_loglevel){

1056

1489

ret = klogctl(7, NULL, 0);

1058

1491

perror("klogctl");

1059

1492

}

1060

1493

}

1061

#endif

1494

#endif /* __linux__ */

1495

/* Lower privileges */

1496

errno = 0;

1497

ret = seteuid(uid);

1498

if(ret == -1){

1499

perror("seteuid");

1500

}

1062

1501

goto end;

1063

1502

}

1064

1503

}

1076

1515

perror("nanosleep");

1077

1516

}

1078

1517

}

1079

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

1080

if(ret == -1){

1081

perror("close");

1518

if(not take_down_interface){

1519

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

1520

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

1521

if(ret == -1){

1522

perror("close");

1523

}

1082

1524

}

1083

1525

#ifdef __linux__

1084

1526

if(restore_loglevel){

1088

1530

perror("klogctl");

1089

1531

}

1090

1532

}

1091

#endif

1092

}

1093

1094

uid = getuid();

1095

gid = getgid();

1096

1097

errno = 0;

1098

setgid(gid);

1099

if(ret == -1){

1100

perror("setgid");

1101

}

1102

1103

ret = setuid(uid);

1104

if(ret == -1){

1105

perror("setuid");

1533

#endif /* __linux__ */

1534

/* Lower privileges */

1535

errno = 0;

1536

if(take_down_interface){

1537

/* Lower privileges */

1538

ret = seteuid(uid);

1539

if(ret == -1){

1540

perror("seteuid");

1541

}

1542

} else {

1543

/* Lower privileges permanently */

1544

ret = setuid(uid);

1545

if(ret == -1){

1546

perror("setuid");

1547

}

1548

}

1549

}

1550

1551

if(quit_now){

1552

goto end;

1106

1553

}

1107

1554

1108

1555

ret = init_gnutls_global(pubkey, seckey);

1109

1556

if(ret == -1){

1110

1557

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

1111

exitcode = EXIT_FAILURE;

1558

exitcode = EX_UNAVAILABLE;

1112

1559

goto end;

1113

1560

} else {

1114

1561

gnutls_initialized = true;

1115

1562

}

1116

1563

1564

if(quit_now){

1565

goto end;

1566

}

1567

1568

tempdir_created = true;

1117

1569

if(mkdtemp(tempdir) == NULL){

1570

tempdir_created = false;

1118

1571

perror("mkdtemp");

1119

1572

goto end;

1120

1573

}

1121

tempdir_created = true;

1574

1575

if(quit_now){

1576

goto end;

1577

}

1122

1578

1123

1579

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

1124

1580

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

1125

exitcode = EXIT_FAILURE;

1581

exitcode = EX_UNAVAILABLE;

1126

1582

goto end;

1127

1583

} else {

1128

1584

gpgme_initialized = true;

1129

1585

}

1130

1586

1131

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

1132

if_index = (AvahiIfIndex) if_nametoindex(interface);

1133

if(if_index == 0){

1134

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

1135

exitcode = EXIT_FAILURE;

1136

goto end;

1137

}

1587

if(quit_now){

1588

goto end;

1138

1589

}

1139

1590

1140

1591

if(connect_to != NULL){

1143

1594

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

1144

1595

if(address == NULL){

1145

1596

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

1146

exitcode = EXIT_FAILURE;

1147

goto end;

1148

}

1597

exitcode = EX_USAGE;

1598

goto end;

1599

}

1600

1601

if(quit_now){

1602

goto end;

1603

}

1604

1149

1605

uint16_t port;

1150

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

1151

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

1152

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

1606

errno = 0;

1607

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

1608

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

1609

or tmpmax != (uint16_t)tmpmax){

1153

1610

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

1154

exitcode = EXIT_FAILURE;

1155

goto end;

1156

}

1611

exitcode = EX_USAGE;

1612

goto end;

1613

}

1614

1615

if(quit_now){

1616

goto end;

1617

}

1618

1157

1619

port = (uint16_t)tmpmax;

1158

1620

*address = '\0';

1159

1621

address = connect_to;

1164

1626

} else {

1165

1627

af = AF_INET;

1166

1628

}

1167

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

1168

if(ret < 0){

1169

exitcode = EXIT_FAILURE;

1170

} else {

1629

1630

if(quit_now){

1631

goto end;

1632

}

1633

1634

while(not quit_now){

1635

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

1636

if(quit_now or ret == 0){

1637

break;

1638

}

1639

sleep(15);

1640

};

1641

1642

if (not quit_now){

1171

1643

exitcode = EXIT_SUCCESS;

1172

1644

}

1645

1173

1646

goto end;

1174

1647

}

1175

1648

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;

1649

if(quit_now){

1188

1650

goto end;

1189

1651

}

1190

1652

1210

1672

if(mc.server == NULL){

1211

1673

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

1212

1674

avahi_strerror(error));

1213

exitcode = EXIT_FAILURE;

1675

exitcode = EX_UNAVAILABLE;

1676

goto end;

1677

}

1678

1679

if(quit_now){

1214

1680

goto end;

1215

1681

}

1216

1682

1217

1683

/* Create the Avahi service browser */

1218

1684

sb = avahi_s_service_browser_new(mc.server, if_index,

1219

AVAHI_PROTO_INET6, "_mandos._tcp",

1685

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1220

1686

NULL, 0, browse_callback, NULL);

1221

1687

if(sb == NULL){

1222

1688

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

1223

1689

avahi_strerror(avahi_server_errno(mc.server)));

1224

exitcode = EXIT_FAILURE;

1690

exitcode = EX_UNAVAILABLE;

1225

1691

goto end;

1226

1692

}

1227

1693

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;

1694

if(quit_now){

1233

1695

goto end;

1234

1696

}

1235

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

1236

if(ret == -1){

1237

perror("sigaction");

1238

exitcode = EXIT_FAILURE;

1239

goto end;

1240

}

1241

1697

1242

1698

/* Run the main loop */

1243

1699

1273

1729

gpgme_release(mc.ctx);

1274

1730

}

1275

1731

1732

/* Take down the network interface */

1733

if(take_down_interface){

1734

/* Re-raise priviliges */

1735

errno = 0;

1736

ret = seteuid(0);

1737

if(ret == -1){

1738

perror("seteuid");

1739

}

1740

if(geteuid() == 0){

1741

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

1742

if(ret == -1){

1743

perror("ioctl SIOCGIFFLAGS");

1744

} else if(network.ifr_flags & IFF_UP) {

1745

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

1746

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

1747

if(ret == -1){

1748

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1749

}

1750

}

1751

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

1752

if(ret == -1){

1753

perror("close");

1754

}

1755

/* Lower privileges permanently */

1756

errno = 0;

1757

ret = setuid(uid);

1758

if(ret == -1){

1759

perror("setuid");

1760

}

1761

}

1762

}

1763

1276

1764

/* Removes the temp directory used by GPGME */

1277

1765

if(tempdir_created){

1278

1766

DIR *d;

1317

1805

}

1318

1806

}

1319

1807

1808

if(quit_now){

1809

sigemptyset(&old_sigterm_action.sa_mask);

1810

old_sigterm_action.sa_handler = SIG_DFL;

1811

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1812

&old_sigterm_action,

1813

NULL));

1814

if(ret == -1){

1815

perror("sigaction");

1816

}

1817

do {

1818

ret = raise(signal_received);

1819

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

1820

if(ret != 0){

1821

perror("raise");

1822

abort();

1823

}

1824

TEMP_FAILURE_RETRY(pause());

1825

}

1826

1320

1827

return exitcode;

1321

1828

}