/mandos/trunk : revision 312

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

43

39

stdout, ferror(), remove() */

44

40

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

45

41

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

46

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

47

strtof(), abort() */

42

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

43

srand(), strtof() */

48

44

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

49

45

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

50

46

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

63

59

strtoimax() */

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() */

76

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

70

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

71

setgid() */

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

79

75

argp_state, struct argp,

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 {

146

138

.dh_bits = 1024, .priority = "SECURE256"

147

139

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

148

140

149

sig_atomic_t quit_now = 0;

150

int signal_received = 0;

151

152

141

/*

153

142

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

154

143

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

171

160

*/

172

161

static bool init_gpgme(const char *seckey,

173

162

const char *pubkey, const char *tempdir){

163

int ret;

174

164

gpgme_error_t rc;

175

165

gpgme_engine_info_t engine_info;

176

166

179

169

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

180

170

*/

181

171

bool import_key(const char *filename){

182

int ret;

183

172

int fd;

184

173

gpgme_data_t pgp_data;

185

174

256

245

return false;

257

246

}

258

247

259

return true;

248

return true;

260

249

}

261

250

262

251

/*

316

305

}

317

306

gpgme_recipient_t recipient;

318

307

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;

308

if(recipient){

309

while(recipient != NULL){

310

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

311

gpgme_pubkey_algo_name(recipient->pubkey_algo));

312

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

313

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

314

recipient->status == GPG_ERR_NO_SECKEY

315

? "No" : "Yes");

316

recipient = recipient->next;

317

}

327

318

}

328

319

}

329

320

}

423

414

}

424

415

425

416

/* OpenPGP credentials */

426

ret = gnutls_certificate_allocate_credentials(&mc.cred);

417

gnutls_certificate_allocate_credentials(&mc.cred);

427

418

if(ret != GNUTLS_E_SUCCESS){

428

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

419

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

420

from

421

-Wunreachable-code

422

*/

429

423

safer_gnutls_strerror(ret));

430

424

gnutls_global_deinit();

431

425

return -1;

478

472

static int init_gnutls_session(gnutls_session_t *session){

479

473

int ret;

480

474

/* GnuTLS session creation */

481

do {

482

ret = gnutls_init(session, GNUTLS_SERVER);

483

if(quit_now){

484

return -1;

485

}

486

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

475

ret = gnutls_init(session, GNUTLS_SERVER);

487

476

if(ret != GNUTLS_E_SUCCESS){

488

477

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

489

478

safer_gnutls_strerror(ret));

491

480

492

481

{

493

482

const char *err;

494

do {

495

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

496

if(quit_now){

497

gnutls_deinit(*session);

498

return -1;

499

}

500

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

483

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

501

484

if(ret != GNUTLS_E_SUCCESS){

502

485

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

503

486

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

507

490

}

508

491

}

509

492

510

do {

511

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

512

mc.cred);

513

if(quit_now){

514

gnutls_deinit(*session);

515

return -1;

516

}

517

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

493

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

494

mc.cred);

518

495

if(ret != GNUTLS_E_SUCCESS){

519

496

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

520

497

safer_gnutls_strerror(ret));

523

500

}

524

501

525

502

/* ignore client certificate if any. */

526

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

503

gnutls_certificate_server_set_request(*session,

504

GNUTLS_CERT_IGNORE);

527

505

528

506

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

529

507

538

516

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

539

517

AvahiIfIndex if_index,

540

518

int af){

541

int ret, tcp_sd = -1;

519

int ret, tcp_sd;

542

520

ssize_t sret;

543

521

union {

544

522

struct sockaddr_in in;

545

523

struct sockaddr_in6 in6;

546

524

} to;

547

525

char *buffer = NULL;

548

char *decrypted_buffer = NULL;

526

char *decrypted_buffer;

549

527

size_t buffer_length = 0;

550

528

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

551

530

size_t written;

552

int retval = -1;

531

int retval = 0;

553

532

gnutls_session_t session;

554

533

int pf; /* Protocol family */

555

534

556

errno = 0;

557

558

if(quit_now){

559

errno = EINTR;

560

return -1;

561

}

562

563

535

switch(af){

564

536

case AF_INET6:

565

537

pf = PF_INET6;

569

541

break;

570

542

default:

571

543

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

572

errno = EINVAL;

573

544

return -1;

574

545

}

575

546

585

556

586

557

tcp_sd = socket(pf, SOCK_STREAM, 0);

587

558

if(tcp_sd < 0){

588

int e = errno;

589

559

perror("socket");

590

errno = e;

591

goto mandos_end;

592

}

593

594

if(quit_now){

595

errno = EINTR;

596

goto mandos_end;

560

return -1;

597

561

}

598

562

599

563

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

600

564

if(af == AF_INET6){

601

to.in6.sin6_family = (sa_family_t)af;

565

to.in6.sin6_family = (uint16_t)af;

602

566

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

603

567

} else { /* IPv4 */

604

568

to.in.sin_family = (sa_family_t)af;

605

569

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

606

570

}

607

571

if(ret < 0 ){

608

int e = errno;

609

572

perror("inet_pton");

610

errno = e;

611

goto mandos_end;

573

return -1;

612

574

}

613

575

if(ret == 0){

614

int e = errno;

615

576

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

616

errno = e;

617

goto mandos_end;

577

return -1;

618

578

}

619

579

if(af == AF_INET6){

620

580

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

627

587

if(if_index == AVAHI_IF_UNSPEC){

628

588

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

629

589

" without a network interface\n");

630

errno = EINVAL;

631

goto mandos_end;

590

return -1;

632

591

}

633

592

/* Set the network interface number as scope */

634

593

to.in6.sin6_scope_id = (uint32_t)if_index;

639

598

-Wunreachable-code */

640

599

}

641

600

642

if(quit_now){

643

errno = EINTR;

644

goto mandos_end;

645

}

646

647

601

if(debug){

648

602

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

649

603

char interface[IF_NAMESIZE];

676

630

}

677

631

}

678

632

679

if(quit_now){

680

errno = EINTR;

681

goto mandos_end;

682

}

683

684

633

if(af == AF_INET6){

685

634

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

686

635

} else {

687

636

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

688

637

}

689

638

if(ret < 0){

690

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

691

int e = errno;

692

perror("connect");

693

errno = e;

694

}

695

goto mandos_end;

696

}

697

698

if(quit_now){

699

errno = EINTR;

700

goto mandos_end;

639

perror("connect");

640

return -1;

701

641

}

702

642

703

643

const char *out = mandos_protocol_version;

707

647

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

708

648

out_size - written));

709

649

if(ret == -1){

710

int e = errno;

711

650

perror("write");

712

errno = e;

651

retval = -1;

713

652

goto mandos_end;

714

653

}

715

654

written += (size_t)ret;

723

662

break;

724

663

}

725

664

}

726

727

if(quit_now){

728

errno = EINTR;

729

goto mandos_end;

730

}

731

665

}

732

666

733

667

if(debug){

734

668

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

735

669

}

736

670

737

if(quit_now){

738

errno = EINTR;

739

goto mandos_end;

740

}

741

742

671

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

743

672

744

if(quit_now){

745

errno = EINTR;

746

goto mandos_end;

747

}

748

749

do {

673

do{

750

674

ret = gnutls_handshake(session);

751

if(quit_now){

752

errno = EINTR;

753

goto mandos_end;

754

}

755

675

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

756

676

757

677

if(ret != GNUTLS_E_SUCCESS){

759

679

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

760

680

gnutls_perror(ret);

761

681

}

762

errno = EPROTO;

682

retval = -1;

763

683

goto mandos_end;

764

684

}

765

685

771

691

}

772

692

773

693

while(true){

774

775

if(quit_now){

776

errno = EINTR;

777

goto mandos_end;

778

}

779

780

694

buffer_capacity = incbuffer(&buffer, buffer_length,

781

695

buffer_capacity);

782

696

if(buffer_capacity == 0){

783

int e = errno;

784

697

perror("incbuffer");

785

errno = e;

786

goto mandos_end;

787

}

788

789

if(quit_now){

790

errno = EINTR;

698

retval = -1;

791

699

goto mandos_end;

792

700

}

793

701

802

710

case GNUTLS_E_AGAIN:

803

711

break;

804

712

case GNUTLS_E_REHANDSHAKE:

805

do {

713

do{

806

714

ret = gnutls_handshake(session);

807

808

if(quit_now){

809

errno = EINTR;

810

goto mandos_end;

811

}

812

715

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

813

716

if(ret < 0){

814

717

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

815

718

gnutls_perror(ret);

816

errno = EPROTO;

719

retval = -1;

817

720

goto mandos_end;

818

721

}

819

722

break;

820

723

default:

821

724

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

822

725

" encrypted session with Mandos server\n");

726

retval = -1;

823

727

gnutls_bye(session, GNUTLS_SHUT_RDWR);

824

errno = EIO;

825

728

goto mandos_end;

826

729

}

827

730

} else {

833

736

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

834

737

}

835

738

836

if(quit_now){

837

errno = EINTR;

838

goto mandos_end;

839

}

840

841

do {

842

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

846

}

847

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

739

gnutls_bye(session, GNUTLS_SHUT_RDWR);

848

740

849

741

if(buffer_length > 0){

850

ssize_t decrypted_buffer_size;

851

742

decrypted_buffer_size = pgp_packet_decrypt(buffer,

852

743

buffer_length,

853

744

&decrypted_buffer);

854

745

if(decrypted_buffer_size >= 0){

855

856

746

written = 0;

857

747

while(written < (size_t) decrypted_buffer_size){

858

if(quit_now){

859

errno = EINTR;

860

goto mandos_end;

861

}

862

863

748

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

864

749

(size_t)decrypted_buffer_size - written,

865

750

stdout);

866

751

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

867

int e = errno;

868

752

if(debug){

869

753

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

870

754

strerror(errno));

871

755

}

872

errno = e;

873

goto mandos_end;

756

retval = -1;

757

break;

874

758

}

875

759

written += (size_t)ret;

876

760

}

877

retval = 0;

761

free(decrypted_buffer);

762

} else {

763

retval = -1;

878

764

}

765

} else {

766

retval = -1;

879

767

}

880

768

881

769

/* Shutdown procedure */

882

770

883

771

mandos_end:

884

{

885

int e = errno;

886

free(decrypted_buffer);

887

free(buffer);

888

if(tcp_sd >= 0){

889

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

890

}

891

if(ret == -1){

892

if(e == 0){

893

e = errno;

894

}

895

perror("close");

896

}

897

gnutls_deinit(session);

898

if(quit_now){

899

e = EINTR;

900

retval = -1;

901

}

902

errno = e;

772

free(buffer);

773

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

774

if(ret == -1){

775

perror("close");

903

776

}

777

gnutls_deinit(session);

904

778

return retval;

905

779

}

906

780

923

797

/* Called whenever a service has been resolved successfully or

924

798

timed out */

925

799

926

if(quit_now){

927

return;

928

}

929

930

800

switch(event){

931

801

default:

932

802

case AVAHI_RESOLVER_FAILURE:

969

839

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

970

840

is removed from the LAN */

971

841

972

if(quit_now){

973

return;

974

}

975

976

842

switch(event){

977

843

default:

978

844

case AVAHI_BROWSER_FAILURE:

988

854

the callback function is called the Avahi server will free the

989

855

resolver for us. */

990

856

991

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

992

name, type, domain, protocol, 0,

993

resolve_callback, NULL) == NULL)

857

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

858

protocol, name, type, domain,

859

AVAHI_PROTO_INET6, 0,

860

resolve_callback, NULL)))

994

861

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

995

862

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

996

863

break;

1007

874

}

1008

875

}

1009

876

877

sig_atomic_t quit_now = 0;

878

1010

879

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

1011

static void handle_sigterm(int sig){

880

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

1012

881

if(quit_now){

1013

882

return;

1014

883

}

1015

884

quit_now = 1;

1016

signal_received = sig;

1017

885

int old_errno = errno;

1018

886

if(mc.simple_poll != NULL){

1019

887

avahi_simple_poll_quit(mc.simple_poll);

1021

889

errno = old_errno;

1022

890

}

1023

891

1024

/*

1025

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

1026

* corresponds to an acceptable network device.

1027

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

1028

*/

1029

int good_interface(const struct dirent *if_entry){

1030

ssize_t ssret;

1031

char *flagname = NULL;

1032

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

1033

return 0;

1034

}

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

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

1042

if(flags_fd == -1){

1043

perror("open");

1044

free(flagname);

1045

return 0;

1046

}

1047

free(flagname);

1048

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

1049

/* read line from flags_fd */

1050

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1051

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

1052

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

1053

if(flagstring == NULL){

1054

perror("malloc");

1055

close(flags_fd);

1056

return 0;

1057

}

1058

while(to_read > 0){

1059

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

1060

(size_t)to_read));

1061

if(ssret == -1){

1062

perror("read");

1063

free(flagstring);

1064

close(flags_fd);

1065

return 0;

1066

}

1067

to_read -= ssret;

1068

if(ssret == 0){

1069

break;

1070

}

1071

}

1072

close(flags_fd);

1073

intmax_t tmpmax;

1074

char *tmp;

1075

errno = 0;

1076

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

1077

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

1078

and not (isspace(*tmp)))

1079

or tmpmax != (ifreq_flags)tmpmax){

1080

if(debug){

1081

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

1082

flagstring, if_entry->d_name);

1083

}

1084

free(flagstring);

1085

return 0;

1086

}

1087

free(flagstring);

1088

ifreq_flags flags = (ifreq_flags)tmpmax;

1089

/* Reject the loopback device */

1090

if(flags & IFF_LOOPBACK){

1091

if(debug){

1092

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

1093

if_entry->d_name);

1094

}

1095

return 0;

1096

}

1097

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

1098

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

1099

if(debug){

1100

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

1101

if_entry->d_name);

1102

}

1103

return 1;

1104

}

1105

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

1106

if(not (flags & IFF_BROADCAST)){

1107

if(debug){

1108

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

1109

if_entry->d_name);

1110

}

1111

return 0;

1112

}

1113

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

1114

if(flags & IFF_NOARP){

1115

if(debug){

1116

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

1117

if_entry->d_name);

1118

}

1119

return 0;

1120

}

1121

/* Accept this device */

1122

if(debug){

1123

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

1124

if_entry->d_name);

1125

}

1126

return 1;

1127

}

1128

1129

892

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

1130

893

AvahiSServiceBrowser *sb = NULL;

1131

894

int error;

1133

896

intmax_t tmpmax;

1134

897

char *tmp;

1135

898

int exitcode = EXIT_SUCCESS;

1136

const char *interface = "";

899

const char *interface = "eth0";

1137

900

struct ifreq network;

1138

int sd = -1;

1139

bool take_down_interface = false;

901

int sd;

1140

902

uid_t uid;

1141

903

gid_t gid;

904

char *connect_to = NULL;

1142

905

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

1143

906

bool tempdir_created = false;

1144

907

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1145

908

const char *seckey = PATHDIR "/" SECKEY;

1146

909

const char *pubkey = PATHDIR "/" PUBKEY;

1147

910

911

/* Initialize Mandos context */

912

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

913

.dh_bits = 1024, .priority = "SECURE256"

914

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

1148

915

bool gnutls_initialized = false;

1149

916

bool gpgme_initialized = false;

1150

917

float delay = 2.5f;

1151

918

1152

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

919

struct sigaction old_sigterm_action;

1153

920

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1154

921

1155

uid = getuid();

1156

gid = getgid();

1157

1158

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

1159

errno = 0;

1160

ret = setgid(gid);

1161

if(ret == -1){

1162

perror("setgid");

1163

}

1164

1165

/* Lower user privileges (temporarily) */

1166

errno = 0;

1167

ret = seteuid(uid);

1168

if(ret == -1){

1169

perror("seteuid");

1170

}

1171

1172

if(quit_now){

1173

goto end;

1174

}

1175

1176

922

{

1177

923

struct argp_option options[] = {

1178

924

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

1207

953

.arg = "SECONDS",

1208

954

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

1209

955

.group = 2 },

1210

/*

1211

* These reproduce what we would get without ARGP_NO_HELP

1212

*/

1213

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

1214

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

1215

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

1216

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

1217

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

1218

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

1219

956

{ .name = NULL }

1220

957

};

1221

958

1222

959

error_t parse_opt(int key, char *arg,

1223

960

struct argp_state *state){

1224

errno = 0;

1225

961

switch(key){

1226

962

case 128: /* --debug */

1227

963

debug = true;

1243

979

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

1244

980

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

1245

981

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

1246

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

982

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

983

exit(EXIT_FAILURE);

1247

984

}

1248

985

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

1249

986

break;

1254

991

errno = 0;

1255

992

delay = strtof(arg, &tmp);

1256

993

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

1257

argp_error(state, "Bad delay");

994

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

995

exit(EXIT_FAILURE);

1258

996

}

1259

997

break;

1260

/*

1261

* These reproduce what we would get without ARGP_NO_HELP

1262

*/

1263

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

1264

argp_state_help(state, state->out_stream,

1265

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1266

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1267

case -3: /* --usage */

1268

argp_state_help(state, state->out_stream,

1269

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1270

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

1271

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

1272

exit(argp_err_exit_status);

998

case ARGP_KEY_ARG:

999

argp_usage(state);

1000

case ARGP_KEY_END:

1273

1001

break;

1274

1002

default:

1275

1003

return ARGP_ERR_UNKNOWN;

1276

1004

}

1277

return errno;

1005

return 0;

1278

1006

}

1279

1007

1280

1008

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

1281

1009

.args_doc = "",

1282

1010

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

1283

1011

" passwords from a Mandos server" };

1284

ret = argp_parse(&argp, argc, argv,

1285

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1286

switch(ret){

1287

case 0:

1288

break;

1289

case ENOMEM:

1290

default:

1291

errno = ret;

1292

perror("argp_parse");

1293

exitcode = EX_OSERR;

1294

goto end;

1295

case EINVAL:

1296

exitcode = EX_USAGE;

1012

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

1013

if(ret == ARGP_ERR_UNKNOWN){

1014

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

1015

exitcode = EXIT_FAILURE;

1297

1016

goto end;

1298

1017

}

1299

1018

}

1301

1020

if(not debug){

1302

1021

avahi_set_log_function(empty_log);

1303

1022

}

1304

1305

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

1306

struct dirent **direntries;

1307

ret = scandir(sys_class_net, &direntries, good_interface,

1308

alphasort);

1309

if(ret >= 1){

1310

/* Pick the first good interface */

1311

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

1312

if(debug){

1313

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

1314

}

1315

if(interface == NULL){

1316

perror("malloc");

1317

free(direntries);

1318

exitcode = EXIT_FAILURE;

1319

goto end;

1320

}

1321

free(direntries);

1322

} else {

1323

free(direntries);

1324

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

1325

exitcode = EXIT_FAILURE;

1326

goto end;

1327

}

1328

}

1329

1023

1330

1024

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

1331

1025

from the signal handler */

1334

1028

mc.simple_poll = avahi_simple_poll_new();

1335

1029

if(mc.simple_poll == NULL){

1336

1030

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

1337

exitcode = EX_UNAVAILABLE;

1031

exitcode = EXIT_FAILURE;

1338

1032

goto end;

1339

1033

}

1340

1034

1342

1036

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

1343

1037

if(ret == -1){

1344

1038

perror("sigaddset");

1345

exitcode = EX_OSERR;

1039

exitcode = EXIT_FAILURE;

1346

1040

goto end;

1347

1041

}

1348

1042

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

1349

1043

if(ret == -1){

1350

1044

perror("sigaddset");

1351

exitcode = EX_OSERR;

1045

exitcode = EXIT_FAILURE;

1352

1046

goto end;

1353

1047

}

1354

1048

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

1355

1049

if(ret == -1){

1356

1050

perror("sigaddset");

1357

exitcode = EX_OSERR;

1358

goto end;

1359

}

1360

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

1361

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

1362

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

1363

*/

1364

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

1365

if(ret == -1){

1366

perror("sigaction");

1367

return EX_OSERR;

1368

}

1369

if(old_sigterm_action.sa_handler != SIG_IGN){

1370

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

1371

if(ret == -1){

1372

perror("sigaction");

1373

exitcode = EX_OSERR;

1374

goto end;

1375

}

1376

}

1377

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

1378

if(ret == -1){

1379

perror("sigaction");

1380

return EX_OSERR;

1381

}

1382

if(old_sigterm_action.sa_handler != SIG_IGN){

1383

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

1384

if(ret == -1){

1385

perror("sigaction");

1386

exitcode = EX_OSERR;

1387

goto end;

1388

}

1389

}

1390

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

1391

if(ret == -1){

1392

perror("sigaction");

1393

return EX_OSERR;

1394

}

1395

if(old_sigterm_action.sa_handler != SIG_IGN){

1396

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

1397

if(ret == -1){

1398

perror("sigaction");

1399

exitcode = EX_OSERR;

1400

goto end;

1401

}

1402

}

1051

exitcode = EXIT_FAILURE;

1052

goto end;

1053

}

1054

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

1055

if(ret == -1){

1056

perror("sigaction");

1057

exitcode = EXIT_FAILURE;

1058

goto end;

1059

}

1403

1060

1404

1061

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

1405

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

1406

if_index = (AvahiIfIndex) if_nametoindex(interface);

1407

if(if_index == 0){

1408

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

1409

exitcode = EX_UNAVAILABLE;

1410

goto end;

1411

}

1412

1413

if(quit_now){

1414

goto end;

1415

}

1416

1417

/* Re-raise priviliges */

1418

errno = 0;

1419

ret = seteuid(0);

1420

if(ret == -1){

1421

perror("seteuid");

1422

}

1423

1062

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

1424

1063

#ifdef __linux__

1425

1064

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1426

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

1065

messages to mess up the prompt */

1427

1066

ret = klogctl(8, NULL, 5);

1428

1067

bool restore_loglevel = true;

1429

1068

if(ret == -1){

1435

1074

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1436

1075

if(sd < 0){

1437

1076

perror("socket");

1438

exitcode = EX_OSERR;

1077

exitcode = EXIT_FAILURE;

1439

1078

#ifdef __linux__

1440

1079

if(restore_loglevel){

1441

1080

ret = klogctl(7, NULL, 0);

1444

1083

}

1445

1084

}

1446

1085

#endif /* __linux__ */

1447

/* Lower privileges */

1448

errno = 0;

1449

ret = seteuid(uid);

1450

if(ret == -1){

1451

perror("seteuid");

1452

}

1453

1086

goto end;

1454

1087

}

1455

1088

strcpy(network.ifr_name, interface);

1464

1097

}

1465

1098

}

1466

1099

#endif /* __linux__ */

1467

exitcode = EX_OSERR;

1468

/* Lower privileges */

1469

errno = 0;

1470

ret = seteuid(uid);

1471

if(ret == -1){

1472

perror("seteuid");

1473

}

1100

exitcode = EXIT_FAILURE;

1474

1101

goto end;

1475

1102

}

1476

1103

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

1477

1104

network.ifr_flags |= IFF_UP;

1478

take_down_interface = true;

1479

1105

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

1480

1106

if(ret == -1){

1481

take_down_interface = false;

1482

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1483

exitcode = EX_OSERR;

1107

perror("ioctl SIOCSIFFLAGS");

1108

exitcode = EXIT_FAILURE;

1484

1109

#ifdef __linux__

1485

1110

if(restore_loglevel){

1486

1111

ret = klogctl(7, NULL, 0);

1489

1114

}

1490

1115

}

1491

1116

#endif /* __linux__ */

1492

/* Lower privileges */

1493

errno = 0;

1494

ret = seteuid(uid);

1495

if(ret == -1){

1496

perror("seteuid");

1497

}

1498

1117

goto end;

1499

1118

}

1500

1119

}

1512

1131

perror("nanosleep");

1513

1132

}

1514

1133

}

1515

if(not take_down_interface){

1516

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

1517

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

1518

if(ret == -1){

1519

perror("close");

1520

}

1134

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

1135

if(ret == -1){

1136

perror("close");

1521

1137

}

1522

1138

#ifdef __linux__

1523

1139

if(restore_loglevel){

1528

1144

}

1529

1145

}

1530

1146

#endif /* __linux__ */

1531

/* Lower privileges */

1532

errno = 0;

1533

if(take_down_interface){

1534

/* Lower privileges */

1535

ret = seteuid(uid);

1536

if(ret == -1){

1537

perror("seteuid");

1538

}

1539

} else {

1540

/* Lower privileges permanently */

1541

ret = setuid(uid);

1542

if(ret == -1){

1543

perror("setuid");

1544

}

1545

}

1546

}

1547

1548

if(quit_now){

1549

goto end;

1147

}

1148

1149

uid = getuid();

1150

gid = getgid();

1151

1152

errno = 0;

1153

setgid(gid);

1154

if(ret == -1){

1155

perror("setgid");

1156

}

1157

1158

ret = setuid(uid);

1159

if(ret == -1){

1160

perror("setuid");

1550

1161

}

1551

1162

1552

1163

ret = init_gnutls_global(pubkey, seckey);

1553

1164

if(ret == -1){

1554

1165

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

1555

exitcode = EX_UNAVAILABLE;

1166

exitcode = EXIT_FAILURE;

1556

1167

goto end;

1557

1168

} else {

1558

1169

gnutls_initialized = true;

1559

1170

}

1560

1171

1561

if(quit_now){

1562

goto end;

1563

}

1564

1565

tempdir_created = true;

1566

1172

if(mkdtemp(tempdir) == NULL){

1567

tempdir_created = false;

1568

1173

perror("mkdtemp");

1569

1174

goto end;

1570

1175

}

1571

1572

if(quit_now){

1573

goto end;

1574

}

1176

tempdir_created = true;

1575

1177

1576

1178

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

1577

1179

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

1578

exitcode = EX_UNAVAILABLE;

1180

exitcode = EXIT_FAILURE;

1579

1181

goto end;

1580

1182

} else {

1581

1183

gpgme_initialized = true;

1582

1184

}

1583

1185

1584

if(quit_now){

1585

goto end;

1186

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

1187

if_index = (AvahiIfIndex) if_nametoindex(interface);

1188

if(if_index == 0){

1189

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

1190

exitcode = EXIT_FAILURE;

1191

goto end;

1192

}

1586

1193

}

1587

1194

1588

1195

if(connect_to != NULL){

1591

1198

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

1592

1199

if(address == NULL){

1593

1200

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

1594

exitcode = EX_USAGE;

1595

goto end;

1596

}

1597

1598

if(quit_now){

1599

goto end;

1600

}

1601

1201

exitcode = EXIT_FAILURE;

1202

goto end;

1203

}

1602

1204

uint16_t port;

1603

1205

errno = 0;

1604

1206

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

1605

1207

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

1606

1208

or tmpmax != (uint16_t)tmpmax){

1607

1209

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

1608

exitcode = EX_USAGE;

1609

goto end;

1610

}

1611

1612

if(quit_now){

1613

goto end;

1614

}

1615

1210

exitcode = EXIT_FAILURE;

1211

goto end;

1212

}

1616

1213

port = (uint16_t)tmpmax;

1617

1214

*address = '\0';

1618

1215

address = connect_to;

1623

1220

} else {

1624

1221

af = AF_INET;

1625

1222

}

1626

1627

if(quit_now){

1628

goto end;

1629

}

1630

1631

while(not quit_now){

1632

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

1633

if(quit_now or ret == 0){

1634

break;

1635

}

1636

sleep(15);

1637

};

1638

1639

if (not quit_now){

1223

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

1224

if(ret < 0){

1225

exitcode = EXIT_FAILURE;

1226

} else {

1640

1227

exitcode = EXIT_SUCCESS;

1641

1228

}

1642

1643

goto end;

1644

}

1645

1646

if(quit_now){

1647

goto end;

1648

}

1649

1229

goto end;

1230

}

1231

1650

1232

{

1651

1233

AvahiServerConfig config;

1652

1234

/* Do not publish any local Zeroconf records */

1669

1251

if(mc.server == NULL){

1670

1252

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

1671

1253

avahi_strerror(error));

1672

exitcode = EX_UNAVAILABLE;

1673

goto end;

1674

}

1675

1676

if(quit_now){

1254

exitcode = EXIT_FAILURE;

1677

1255

goto end;

1678

1256

}

1679

1257

1680

1258

/* Create the Avahi service browser */

1681

1259

sb = avahi_s_service_browser_new(mc.server, if_index,

1682

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1260

AVAHI_PROTO_INET6, "_mandos._tcp",

1683

1261

NULL, 0, browse_callback, NULL);

1684

1262

if(sb == NULL){

1685

1263

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

1686

1264

avahi_strerror(avahi_server_errno(mc.server)));

1687

exitcode = EX_UNAVAILABLE;

1688

goto end;

1689

}

1690

1691

if(quit_now){

1265

exitcode = EXIT_FAILURE;

1692

1266

goto end;

1693

1267

}

1694

1268

1726

1300

gpgme_release(mc.ctx);

1727

1301

}

1728

1302

1729

/* Take down the network interface */

1730

if(take_down_interface){

1731

/* Re-raise priviliges */

1732

errno = 0;

1733

ret = seteuid(0);

1734

if(ret == -1){

1735

perror("seteuid");

1736

}

1737

if(geteuid() == 0){

1738

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

1739

if(ret == -1){

1740

perror("ioctl SIOCGIFFLAGS");

1741

} else if(network.ifr_flags & IFF_UP) {

1742

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

1743

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

1744

if(ret == -1){

1745

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1746

}

1747

}

1748

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

1749

if(ret == -1){

1750

perror("close");

1751

}

1752

/* Lower privileges permanently */

1753

errno = 0;

1754

ret = setuid(uid);

1755

if(ret == -1){

1756

perror("setuid");

1757

}

1758

}

1759

}

1760

1761

1303

/* Removes the temp directory used by GPGME */

1762

1304

if(tempdir_created){

1763

1305

DIR *d;

1802

1344

}

1803

1345

}

1804

1346

1805

if(quit_now){

1806

sigemptyset(&old_sigterm_action.sa_mask);

1807

old_sigterm_action.sa_handler = SIG_DFL;

1808

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

1809

&old_sigterm_action,

1810

NULL));

1811

if(ret == -1){

1812

perror("sigaction");

1813

}

1814

do {

1815

ret = raise(signal_received);

1816

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

1817

if(ret != 0){

1818

perror("raise");

1819

abort();

1820

}

1821

TEMP_FAILURE_RETRY(pause());

1822

}

1823

1824

1347

return exitcode;

1825

1348

}