/mandos/trunk : revision 308

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

34

33

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

34

#define _FILE_OFFSET_BITS 64

38

#endif

39

35

40

36

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

41

37

42

38

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

43

stdout, ferror(), remove() */

39

stdout, ferror(), sscanf(),

40

remove() */

44

41

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

45

42

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

46

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

47

strtof(), abort() */

43

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

44

srand() */

48

45

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

49

46

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

50

47

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

59

56

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

60

57

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

61

58

*/

62

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

63

strtoimax() */

59

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

64

60

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

65

61

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

66

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

62

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

67

63

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

68

64

SIOCSIFFLAGS, if_indextoname(),

69

65

if_nametoindex(), IF_NAMESIZE */

71

67

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

68

*/

73

69

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

74

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

75

setgid(), pause() */

70

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

71

setgid() */

76

72

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

77

73

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

78

74

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

80

76

argp_parse(), ARGP_KEY_ARG,

81

77

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

78

#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 */

79

sigaction(), SIGTERM, sigaction,

80

sig_atomic_t */

87

81

88

82

#ifdef __linux__

89

83

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

127

121

static const char mandos_protocol_version[] = "1";

128

122

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

129

123

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;

132

124

133

125

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

134

126

typedef struct {

142

134

} mandos_context;

143

135

144

136

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

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

mandos_context mc;

151

138

152

139

/*

153

140

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

171

158

*/

172

159

static bool init_gpgme(const char *seckey,

173

160

const char *pubkey, const char *tempdir){

161

int ret;

174

162

gpgme_error_t rc;

175

163

gpgme_engine_info_t engine_info;

176

164

179

167

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

180

168

*/

181

169

bool import_key(const char *filename){

182

int ret;

183

170

int fd;

184

171

gpgme_data_t pgp_data;

185

172

256

243

return false;

257

244

}

258

245

259

return true;

246

return true;

260

247

}

261

248

262

249

/*

316

303

}

317

304

gpgme_recipient_t recipient;

318

305

recipient = result->recipients;

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;

306

if(recipient){

307

while(recipient != NULL){

308

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

309

gpgme_pubkey_algo_name(recipient->pubkey_algo));

310

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

311

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

312

recipient->status == GPG_ERR_NO_SECKEY

313

? "No" : "Yes");

314

recipient = recipient->next;

315

}

327

316

}

328

317

}

329

318

}

481

470

static int init_gnutls_session(gnutls_session_t *session){

482

471

int ret;

483

472

/* GnuTLS session creation */

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

ret = gnutls_init(session, GNUTLS_SERVER);

490

474

if(ret != GNUTLS_E_SUCCESS){

491

475

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

492

476

safer_gnutls_strerror(ret));

494

478

495

479

{

496

480

const char *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

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

504

482

if(ret != GNUTLS_E_SUCCESS){

505

483

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

506

484

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

510

488

}

511

489

}

512

490

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);

491

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

492

mc.cred);

521

493

if(ret != GNUTLS_E_SUCCESS){

522

494

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

523

495

safer_gnutls_strerror(ret));

526

498

}

527

499

528

500

/* ignore client certificate if any. */

529

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

501

gnutls_certificate_server_set_request(*session,

502

GNUTLS_CERT_IGNORE);

530

503

531

504

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

532

505

541

514

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

542

515

AvahiIfIndex if_index,

543

516

int af){

544

int ret, tcp_sd = -1;

517

int ret, tcp_sd;

545

518

ssize_t sret;

546

519

union {

547

520

struct sockaddr_in in;

548

521

struct sockaddr_in6 in6;

549

522

} to;

550

523

char *buffer = NULL;

551

char *decrypted_buffer = NULL;

524

char *decrypted_buffer;

552

525

size_t buffer_length = 0;

553

526

size_t buffer_capacity = 0;

527

ssize_t decrypted_buffer_size;

554

528

size_t written;

555

int retval = -1;

529

int retval = 0;

556

530

gnutls_session_t session;

557

531

int pf; /* Protocol family */

558

532

559

errno = 0;

560

561

if(quit_now){

562

errno = EINTR;

563

return -1;

564

}

565

566

533

switch(af){

567

534

case AF_INET6:

568

535

pf = PF_INET6;

572

539

break;

573

540

default:

574

541

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

575

errno = EINVAL;

576

542

return -1;

577

543

}

578

544

588

554

589

555

tcp_sd = socket(pf, SOCK_STREAM, 0);

590

556

if(tcp_sd < 0){

591

int e = errno;

592

557

perror("socket");

593

errno = e;

594

goto mandos_end;

595

}

596

597

if(quit_now){

598

errno = EINTR;

599

goto mandos_end;

558

return -1;

600

559

}

601

560

602

561

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

603

562

if(af == AF_INET6){

604

to.in6.sin6_family = (sa_family_t)af;

563

to.in6.sin6_family = (uint16_t)af;

605

564

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

606

565

} else { /* IPv4 */

607

566

to.in.sin_family = (sa_family_t)af;

608

567

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

609

568

}

610

569

if(ret < 0 ){

611

int e = errno;

612

570

perror("inet_pton");

613

errno = e;

614

goto mandos_end;

571

return -1;

615

572

}

616

573

if(ret == 0){

617

int e = errno;

618

574

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

619

errno = e;

620

goto mandos_end;

575

return -1;

621

576

}

622

577

if(af == AF_INET6){

623

578

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

630

585

if(if_index == AVAHI_IF_UNSPEC){

631

586

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

632

587

" without a network interface\n");

633

errno = EINVAL;

634

goto mandos_end;

588

return -1;

635

589

}

636

590

/* Set the network interface number as scope */

637

591

to.in6.sin6_scope_id = (uint32_t)if_index;

642

596

-Wunreachable-code */

643

597

}

644

598

645

if(quit_now){

646

errno = EINTR;

647

goto mandos_end;

648

}

649

650

599

if(debug){

651

600

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

652

601

char interface[IF_NAMESIZE];

679

628

}

680

629

}

681

630

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

687

631

if(af == AF_INET6){

688

632

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

689

633

} else {

690

634

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

691

635

}

692

636

if(ret < 0){

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;

637

perror("connect");

638

return -1;

704

639

}

705

640

706

641

const char *out = mandos_protocol_version;

710

645

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

711

646

out_size - written));

712

647

if(ret == -1){

713

int e = errno;

714

648

perror("write");

715

errno = e;

649

retval = -1;

716

650

goto mandos_end;

717

651

}

718

652

written += (size_t)ret;

726

660

break;

727

661

}

728

662

}

729

730

if(quit_now){

731

errno = EINTR;

732

goto mandos_end;

733

}

734

663

}

735

664

736

665

if(debug){

737

666

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

738

667

}

739

668

740

if(quit_now){

741

errno = EINTR;

742

goto mandos_end;

743

}

744

745

669

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

746

670

747

if(quit_now){

748

errno = EINTR;

749

goto mandos_end;

750

}

751

752

do {

671

do{

753

672

ret = gnutls_handshake(session);

754

if(quit_now){

755

errno = EINTR;

756

goto mandos_end;

757

}

758

673

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

759

674

760

675

if(ret != GNUTLS_E_SUCCESS){

762

677

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

763

678

gnutls_perror(ret);

764

679

}

765

errno = EPROTO;

680

retval = -1;

766

681

goto mandos_end;

767

682

}

768

683

774

689

}

775

690

776

691

while(true){

777

778

if(quit_now){

779

errno = EINTR;

780

goto mandos_end;

781

}

782

783

692

buffer_capacity = incbuffer(&buffer, buffer_length,

784

693

buffer_capacity);

785

694

if(buffer_capacity == 0){

786

int e = errno;

787

695

perror("incbuffer");

788

errno = e;

789

goto mandos_end;

790

}

791

792

if(quit_now){

793

errno = EINTR;

696

retval = -1;

794

697

goto mandos_end;

795

698

}

796

699

805

708

case GNUTLS_E_AGAIN:

806

709

break;

807

710

case GNUTLS_E_REHANDSHAKE:

808

do {

711

do{

809

712

ret = gnutls_handshake(session);

810

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

815

713

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

816

714

if(ret < 0){

817

715

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

818

716

gnutls_perror(ret);

819

errno = EPROTO;

717

retval = -1;

820

718

goto mandos_end;

821

719

}

822

720

break;

823

721

default:

824

722

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

825

723

" encrypted session with Mandos server\n");

724

retval = -1;

826

725

gnutls_bye(session, GNUTLS_SHUT_RDWR);

827

errno = EIO;

828

726

goto mandos_end;

829

727

}

830

728

} else {

836

734

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

837

735

}

838

736

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

gnutls_bye(session, GNUTLS_SHUT_RDWR);

851

738

852

739

if(buffer_length > 0){

853

ssize_t decrypted_buffer_size;

854

740

decrypted_buffer_size = pgp_packet_decrypt(buffer,

855

741

buffer_length,

856

742

&decrypted_buffer);

857

743

if(decrypted_buffer_size >= 0){

858

859

744

written = 0;

860

745

while(written < (size_t) decrypted_buffer_size){

861

if(quit_now){

862

errno = EINTR;

863

goto mandos_end;

864

}

865

866

746

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

867

747

(size_t)decrypted_buffer_size - written,

868

748

stdout);

869

749

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

870

int e = errno;

871

750

if(debug){

872

751

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

873

752

strerror(errno));

874

753

}

875

errno = e;

876

goto mandos_end;

754

retval = -1;

755

break;

877

756

}

878

757

written += (size_t)ret;

879

758

}

880

retval = 0;

759

free(decrypted_buffer);

760

} else {

761

retval = -1;

881

762

}

763

} else {

764

retval = -1;

882

765

}

883

766

884

767

/* Shutdown procedure */

885

768

886

769

mandos_end:

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;

770

free(buffer);

771

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

772

if(ret == -1){

773

perror("close");

906

774

}

775

gnutls_deinit(session);

907

776

return retval;

908

777

}

909

778

926

795

/* Called whenever a service has been resolved successfully or

927

796

timed out */

928

797

929

if(quit_now){

930

return;

931

}

932

933

798

switch(event){

934

799

default:

935

800

case AVAHI_RESOLVER_FAILURE:

972

837

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

973

838

is removed from the LAN */

974

839

975

if(quit_now){

976

return;

977

}

978

979

840

switch(event){

980

841

default:

981

842

case AVAHI_BROWSER_FAILURE:

991

852

the callback function is called the Avahi server will free the

992

853

resolver for us. */

993

854

994

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

995

name, type, domain, protocol, 0,

996

resolve_callback, NULL) == NULL)

855

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

856

protocol, name, type, domain,

857

AVAHI_PROTO_INET6, 0,

858

resolve_callback, NULL)))

997

859

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

998

860

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

999

861

break;

1010

872

}

1011

873

}

1012

874

1013

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

1014

static void handle_sigterm(int sig){

875

sig_atomic_t quit_now = 0;

876

877

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

1015

878

if(quit_now){

1016

879

return;

1017

880

}

1018

881

quit_now = 1;

1019

signal_received = sig;

1020

882

int old_errno = errno;

1021

883

if(mc.simple_poll != NULL){

1022

884

avahi_simple_poll_quit(mc.simple_poll);

1024

886

errno = old_errno;

1025

887

}

1026

888

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

/* Accept this device */

1117

if(debug){

1118

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

1119

if_entry->d_name);

1120

}

1121

return 1;

1122

}

1123

1124

889

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

1125

890

AvahiSServiceBrowser *sb = NULL;

1126

891

int error;

1127

892

int ret;

1128

893

intmax_t tmpmax;

1129

char *tmp;

894

int numchars;

1130

895

int exitcode = EXIT_SUCCESS;

1131

const char *interface = "";

896

const char *interface = "eth0";

1132

897

struct ifreq network;

1133

int sd = -1;

1134

bool take_down_interface = false;

898

int sd;

1135

899

uid_t uid;

1136

900

gid_t gid;

901

char *connect_to = NULL;

1137

902

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

1138

903

bool tempdir_created = false;

1139

904

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1140

905

const char *seckey = PATHDIR "/" SECKEY;

1141

906

const char *pubkey = PATHDIR "/" PUBKEY;

1142

907

908

/* Initialize Mandos context */

909

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

910

.dh_bits = 1024, .priority = "SECURE256"

911

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

1143

912

bool gnutls_initialized = false;

1144

913

bool gpgme_initialized = false;

1145

float delay = 2.5f;

1146

1147

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

914

double delay = 2.5;

915

916

struct sigaction old_sigterm_action;

1148

917

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1149

918

1150

uid = getuid();

1151

gid = getgid();

1152

1153

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

1154

errno = 0;

1155

ret = setgid(gid);

1156

if(ret == -1){

1157

perror("setgid");

1158

}

1159

1160

/* Lower user privileges (temporarily) */

1161

errno = 0;

1162

ret = seteuid(uid);

1163

if(ret == -1){

1164

perror("seteuid");

1165

}

1166

1167

if(quit_now){

1168

goto end;

1169

}

1170

1171

919

{

1172

920

struct argp_option options[] = {

1173

921

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

1202

950

.arg = "SECONDS",

1203

951

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

1204

952

.group = 2 },

1205

/*

1206

* These reproduce what we would get without ARGP_NO_HELP

1207

*/

1208

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

1209

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

1210

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

1211

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

1212

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

1213

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

1214

953

{ .name = NULL }

1215

954

};

1216

955

1217

956

error_t parse_opt(int key, char *arg,

1218

957

struct argp_state *state){

1219

errno = 0;

1220

958

switch(key){

1221

959

case 128: /* --debug */

1222

960

debug = true;

1234

972

pubkey = arg;

1235

973

break;

1236

974

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

1237

errno = 0;

1238

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

1239

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

1240

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

1241

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

975

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

976

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

977

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

978

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

979

exit(EXIT_FAILURE);

1242

980

}

1243

981

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

1244

982

break;

1246

984

mc.priority = arg;

1247

985

break;

1248

986

case 131: /* --delay */

1249

errno = 0;

1250

delay = strtof(arg, &tmp);

1251

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

1252

argp_error(state, "Bad delay");

987

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

988

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

989

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

990

exit(EXIT_FAILURE);

1253

991

}

1254

992

break;

1255

/*

1256

* These reproduce what we would get without ARGP_NO_HELP

1257

*/

1258

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

1259

argp_state_help(state, state->out_stream,

1260

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1261

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1262

case -3: /* --usage */

1263

argp_state_help(state, state->out_stream,

1264

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1265

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

1266

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

1267

exit(argp_err_exit_status);

993

case ARGP_KEY_ARG:

994

argp_usage(state);

995

case ARGP_KEY_END:

1268

996

break;

1269

997

default:

1270

998

return ARGP_ERR_UNKNOWN;

1271

999

}

1272

return errno;

1000

return 0;

1273

1001

}

1274

1002

1275

1003

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

1276

1004

.args_doc = "",

1277

1005

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

1278

1006

" passwords from a Mandos server" };

1279

ret = argp_parse(&argp, argc, argv,

1280

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1281

switch(ret){

1282

case 0:

1283

break;

1284

case ENOMEM:

1285

default:

1286

errno = ret;

1287

perror("argp_parse");

1288

exitcode = EX_OSERR;

1289

goto end;

1290

case EINVAL:

1291

exitcode = EX_USAGE;

1292

goto end;

1293

}

1294

}

1295

1296

if(not debug){

1297

avahi_set_log_function(empty_log);

1298

}

1299

1300

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

1301

struct dirent **direntries;

1302

ret = scandir(sys_class_net, &direntries, good_interface,

1303

alphasort);

1304

if(ret >= 1){

1305

/* Pick the first good interface */

1306

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

1307

if(debug){

1308

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

1309

}

1310

if(interface == NULL){

1311

perror("malloc");

1312

free(direntries);

1313

exitcode = EXIT_FAILURE;

1314

goto end;

1315

}

1316

free(direntries);

1317

} else {

1318

free(direntries);

1319

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

1007

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

1008

if(ret == ARGP_ERR_UNKNOWN){

1009

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

1320

1010

exitcode = EXIT_FAILURE;

1321

1011

goto end;

1322

1012

}

1323

1013

}

1324

1014

1325

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

1326

from the signal handler */

1327

/* Initialize the pseudo-RNG for Avahi */

1328

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

1329

mc.simple_poll = avahi_simple_poll_new();

1330

if(mc.simple_poll == NULL){

1331

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

1332

exitcode = EX_UNAVAILABLE;

1333

goto end;

1334

}

1335

1336

sigemptyset(&sigterm_action.sa_mask);

1337

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

1338

if(ret == -1){

1339

perror("sigaddset");

1340

exitcode = EX_OSERR;

1341

goto end;

1342

}

1343

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

1344

if(ret == -1){

1345

perror("sigaddset");

1346

exitcode = EX_OSERR;

1347

goto end;

1348

}

1349

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

1350

if(ret == -1){

1351

perror("sigaddset");

1352

exitcode = EX_OSERR;

1353

goto end;

1354

}

1355

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

1356

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

1357

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

1358

*/

1359

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

1360

if(ret == -1){

1361

perror("sigaction");

1362

return EX_OSERR;

1363

}

1364

if(old_sigterm_action.sa_handler != SIG_IGN){

1365

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

1366

if(ret == -1){

1367

perror("sigaction");

1368

exitcode = EX_OSERR;

1369

goto end;

1370

}

1371

}

1372

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

1373

if(ret == -1){

1374

perror("sigaction");

1375

return EX_OSERR;

1376

}

1377

if(old_sigterm_action.sa_handler != SIG_IGN){

1378

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

1379

if(ret == -1){

1380

perror("sigaction");

1381

exitcode = EX_OSERR;

1382

goto end;

1383

}

1384

}

1385

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

1386

if(ret == -1){

1387

perror("sigaction");

1388

return EX_OSERR;

1389

}

1390

if(old_sigterm_action.sa_handler != SIG_IGN){

1391

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

1392

if(ret == -1){

1393

perror("sigaction");

1394

exitcode = EX_OSERR;

1395

goto end;

1396

}

1397

}

1398

1399

1015

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

1400

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

1401

if_index = (AvahiIfIndex) if_nametoindex(interface);

1402

if(if_index == 0){

1403

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

1404

exitcode = EX_UNAVAILABLE;

1405

goto end;

1406

}

1407

1408

if(quit_now){

1409

goto end;

1410

}

1411

1412

/* Re-raise priviliges */

1413

errno = 0;

1414

ret = seteuid(0);

1415

if(ret == -1){

1416

perror("seteuid");

1417

}

1418

1016

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

1419

1017

#ifdef __linux__

1420

1018

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1421

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

1019

messages to mess up the prompt */

1422

1020

ret = klogctl(8, NULL, 5);

1423

1021

bool restore_loglevel = true;

1424

1022

if(ret == -1){

1430

1028

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1431

1029

if(sd < 0){

1432

1030

perror("socket");

1433

exitcode = EX_OSERR;

1031

exitcode = EXIT_FAILURE;

1434

1032

#ifdef __linux__

1435

1033

if(restore_loglevel){

1436

1034

ret = klogctl(7, NULL, 0);

1439

1037

}

1440

1038

}

1441

1039

#endif /* __linux__ */

1442

/* Lower privileges */

1443

errno = 0;

1444

ret = seteuid(uid);

1445

if(ret == -1){

1446

perror("seteuid");

1447

}

1448

1040

goto end;

1449

1041

}

1450

1042

strcpy(network.ifr_name, interface);

1459

1051

}

1460

1052

}

1461

1053

#endif /* __linux__ */

1462

exitcode = EX_OSERR;

1463

/* Lower privileges */

1464

errno = 0;

1465

ret = seteuid(uid);

1466

if(ret == -1){

1467

perror("seteuid");

1468

}

1054

exitcode = EXIT_FAILURE;

1469

1055

goto end;

1470

1056

}

1471

1057

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

1472

1058

network.ifr_flags |= IFF_UP;

1473

take_down_interface = true;

1474

1059

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

1475

1060

if(ret == -1){

1476

take_down_interface = false;

1477

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1478

exitcode = EX_OSERR;

1061

perror("ioctl SIOCSIFFLAGS");

1062

exitcode = EXIT_FAILURE;

1479

1063

#ifdef __linux__

1480

1064

if(restore_loglevel){

1481

1065

ret = klogctl(7, NULL, 0);

1484

1068

}

1485

1069

}

1486

1070

#endif /* __linux__ */

1487

/* Lower privileges */

1488

errno = 0;

1489

ret = seteuid(uid);

1490

if(ret == -1){

1491

perror("seteuid");

1492

}

1493

1071

goto end;

1494

1072

}

1495

1073

}

1507

1085

perror("nanosleep");

1508

1086

}

1509

1087

}

1510

if(not take_down_interface){

1511

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

1512

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

1513

if(ret == -1){

1514

perror("close");

1515

}

1088

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

1089

if(ret == -1){

1090

perror("close");

1516

1091

}

1517

1092

#ifdef __linux__

1518

1093

if(restore_loglevel){

1523

1098

}

1524

1099

}

1525

1100

#endif /* __linux__ */

1526

/* Lower privileges */

1527

errno = 0;

1528

if(take_down_interface){

1529

/* Lower privileges */

1530

ret = seteuid(uid);

1531

if(ret == -1){

1532

perror("seteuid");

1533

}

1534

} else {

1535

/* Lower privileges permanently */

1536

ret = setuid(uid);

1537

if(ret == -1){

1538

perror("setuid");

1539

}

1540

}

1541

}

1542

1543

if(quit_now){

1544

goto end;

1101

}

1102

1103

uid = getuid();

1104

gid = getgid();

1105

1106

errno = 0;

1107

setgid(gid);

1108

if(ret == -1){

1109

perror("setgid");

1110

}

1111

1112

ret = setuid(uid);

1113

if(ret == -1){

1114

perror("setuid");

1545

1115

}

1546

1116

1547

1117

ret = init_gnutls_global(pubkey, seckey);

1548

1118

if(ret == -1){

1549

1119

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

1550

exitcode = EX_UNAVAILABLE;

1120

exitcode = EXIT_FAILURE;

1551

1121

goto end;

1552

1122

} else {

1553

1123

gnutls_initialized = true;

1554

1124

}

1555

1125

1556

if(quit_now){

1557

goto end;

1558

}

1559

1560

tempdir_created = true;

1561

1126

if(mkdtemp(tempdir) == NULL){

1562

tempdir_created = false;

1563

1127

perror("mkdtemp");

1564

1128

goto end;

1565

1129

}

1566

1567

if(quit_now){

1568

goto end;

1569

}

1130

tempdir_created = true;

1570

1131

1571

1132

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

1572

1133

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

1573

exitcode = EX_UNAVAILABLE;

1134

exitcode = EXIT_FAILURE;

1574

1135

goto end;

1575

1136

} else {

1576

1137

gpgme_initialized = true;

1577

1138

}

1578

1139

1579

if(quit_now){

1580

goto end;

1140

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

1141

if_index = (AvahiIfIndex) if_nametoindex(interface);

1142

if(if_index == 0){

1143

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

1144

exitcode = EXIT_FAILURE;

1145

goto end;

1146

}

1581

1147

}

1582

1148

1583

1149

if(connect_to != NULL){

1586

1152

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

1587

1153

if(address == NULL){

1588

1154

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

1589

exitcode = EX_USAGE;

1590

goto end;

1591

}

1592

1593

if(quit_now){

1594

goto end;

1595

}

1596

1155

exitcode = EXIT_FAILURE;

1156

goto end;

1157

}

1597

1158

uint16_t port;

1598

errno = 0;

1599

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

1600

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

1601

or tmpmax != (uint16_t)tmpmax){

1159

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

1160

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

1161

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

1602

1162

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

1603

exitcode = EX_USAGE;

1604

goto end;

1605

}

1606

1607

if(quit_now){

1608

goto end;

1609

}

1610

1163

exitcode = EXIT_FAILURE;

1164

goto end;

1165

}

1611

1166

port = (uint16_t)tmpmax;

1612

1167

*address = '\0';

1613

1168

address = connect_to;

1618

1173

} else {

1619

1174

af = AF_INET;

1620

1175

}

1621

1622

if(quit_now){

1623

goto end;

1624

}

1625

1626

while(not quit_now){

1627

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

1628

if(quit_now or ret == 0){

1629

break;

1630

}

1631

sleep(15);

1632

};

1633

1634

if (not quit_now){

1176

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

1177

if(ret < 0){

1178

exitcode = EXIT_FAILURE;

1179

} else {

1635

1180

exitcode = EXIT_SUCCESS;

1636

1181

}

1637

1638

1182

goto end;

1639

1183

}

1640

1184

1641

if(quit_now){

1185

if(not debug){

1186

avahi_set_log_function(empty_log);

1187

}

1188

1189

/* Initialize the pseudo-RNG for Avahi */

1190

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

1191

1192

/* Allocate main Avahi loop object */

1193

mc.simple_poll = avahi_simple_poll_new();

1194

if(mc.simple_poll == NULL){

1195

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

1196

exitcode = EXIT_FAILURE;

1642

1197

goto end;

1643

1198

}

1644

1199

1664

1219

if(mc.server == NULL){

1665

1220

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

1666

1221

avahi_strerror(error));

1667

exitcode = EX_UNAVAILABLE;

1668

goto end;

1669

}

1670

1671

if(quit_now){

1222

exitcode = EXIT_FAILURE;

1672

1223

goto end;

1673

1224

}

1674

1225

1675

1226

/* Create the Avahi service browser */

1676

1227

sb = avahi_s_service_browser_new(mc.server, if_index,

1677

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1228

AVAHI_PROTO_INET6, "_mandos._tcp",

1678

1229

NULL, 0, browse_callback, NULL);

1679

1230

if(sb == NULL){

1680

1231

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

1681

1232

avahi_strerror(avahi_server_errno(mc.server)));

1682

exitcode = EX_UNAVAILABLE;

1233

exitcode = EXIT_FAILURE;

1683

1234

goto end;

1684

1235

}

1685

1236

1686

if(quit_now){

1687

goto end;

1688

}

1237

sigemptyset(&sigterm_action.sa_mask);

1238

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

1239

if(ret == -1){

1240

perror("sigaddset");

1241

exitcode = EXIT_FAILURE;

1242

goto end;

1243

}

1244

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

1245

if(ret == -1){

1246

perror("sigaddset");

1247

exitcode = EXIT_FAILURE;

1248

goto end;

1249

}

1250

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

1251

if(ret == -1){

1252

perror("sigaddset");

1253

exitcode = EXIT_FAILURE;

1254

goto end;

1255

}

1256

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

1257

if(ret == -1){

1258

perror("sigaction");

1259

exitcode = EXIT_FAILURE;

1260

goto end;

1261

}

1689

1262

1690

1263

/* Run the main loop */

1691

1264

1721

1294

gpgme_release(mc.ctx);

1722

1295

}

1723

1296

1724

/* Take down the network interface */

1725

if(take_down_interface){

1726

/* Re-raise priviliges */

1727

errno = 0;

1728

ret = seteuid(0);

1729

if(ret == -1){

1730

perror("seteuid");

1731

}

1732

if(geteuid() == 0){

1733

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

1734

if(ret == -1){

1735

perror("ioctl SIOCGIFFLAGS");

1736

} else if(network.ifr_flags & IFF_UP) {

1737

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

1738

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

1739

if(ret == -1){

1740

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1741

}

1742

}

1743

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

1744

if(ret == -1){

1745

perror("close");

1746

}

1747

/* Lower privileges permanently */

1748

errno = 0;

1749

ret = setuid(uid);

1750

if(ret == -1){

1751

perror("setuid");

1752

}

1753

}

1754

}

1755

1756

1297

/* Removes the temp directory used by GPGME */

1757

1298

if(tempdir_created){

1758

1299

DIR *d;

1797

1338

}

1798

1339

}

1799

1340

1800

if(quit_now){

1801

sigemptyset(&old_sigterm_action.sa_mask);

1802

old_sigterm_action.sa_handler = SIG_DFL;

1803

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1804

&old_sigterm_action,

1805

NULL));

1806

if(ret == -1){

1807

perror("sigaction");

1808

}

1809

do {

1810

ret = raise(signal_received);

1811

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

1812

if(ret != 0){

1813

perror("raise");

1814

abort();

1815

}

1816

TEMP_FAILURE_RETRY(pause());

1817

}

1818

1819

1341

return exitcode;

1820

1342

}