/mandos/release : revision 237.2.186

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

66

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

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,

80

sig_atomic_t */

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 */

81

87

82

88

#ifdef __linux__

83

89

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

121

127

static const char mandos_protocol_version[] = "1";

122

128

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

123

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;

124

132

125

133

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

126

134

typedef struct {

138

146

.dh_bits = 1024, .priority = "SECURE256"

139

147

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

140

148

149

sig_atomic_t quit_now = 0;

150

int signal_received = 0;

151

141

152

/*

142

153

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

143

154

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

160

171

*/

161

172

static bool init_gpgme(const char *seckey,

162

173

const char *pubkey, const char *tempdir){

163

int ret;

164

174

gpgme_error_t rc;

165

175

gpgme_engine_info_t engine_info;

166

176

169

179

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

170

180

*/

171

181

bool import_key(const char *filename){

182

int ret;

172

183

int fd;

173

184

gpgme_data_t pgp_data;

174

185

245

256

return false;

246

257

}

247

258

248

return true;

259

return true;

249

260

}

250

261

251

262

/*

305

316

}

306

317

gpgme_recipient_t recipient;

307

318

recipient = result->recipients;

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

}

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;

318

327

}

319

328

}

320

329

}

472

481

static int init_gnutls_session(gnutls_session_t *session){

473

482

int ret;

474

483

/* GnuTLS session creation */

475

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);

476

490

if(ret != GNUTLS_E_SUCCESS){

477

491

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

478

492

safer_gnutls_strerror(ret));

480

494

481

495

{

482

496

const char *err;

483

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);

484

504

if(ret != GNUTLS_E_SUCCESS){

485

505

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

486

506

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

490

510

}

491

511

}

492

512

493

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

494

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);

495

521

if(ret != GNUTLS_E_SUCCESS){

496

522

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

497

523

safer_gnutls_strerror(ret));

500

526

}

501

527

502

528

/* ignore client certificate if any. */

503

gnutls_certificate_server_set_request(*session,

504

GNUTLS_CERT_IGNORE);

529

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

505

530

506

531

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

507

532

516

541

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

517

542

AvahiIfIndex if_index,

518

543

int af){

519

int ret, tcp_sd;

544

int ret, tcp_sd = -1;

520

545

ssize_t sret;

521

546

union {

522

547

struct sockaddr_in in;

523

548

struct sockaddr_in6 in6;

524

549

} to;

525

550

char *buffer = NULL;

526

char *decrypted_buffer;

551

char *decrypted_buffer = NULL;

527

552

size_t buffer_length = 0;

528

553

size_t buffer_capacity = 0;

529

ssize_t decrypted_buffer_size;

530

554

size_t written;

531

int retval = 0;

555

int retval = -1;

532

556

gnutls_session_t session;

533

557

int pf; /* Protocol family */

534

558

559

errno = 0;

560

561

if(quit_now){

562

errno = EINTR;

563

return -1;

564

}

565

535

566

switch(af){

536

567

case AF_INET6:

537

568

pf = PF_INET6;

541

572

break;

542

573

default:

543

574

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

575

errno = EINVAL;

544

576

return -1;

545

577

}

546

578

556

588

557

589

tcp_sd = socket(pf, SOCK_STREAM, 0);

558

590

if(tcp_sd < 0){

591

int e = errno;

559

592

perror("socket");

560

return -1;

593

errno = e;

594

goto mandos_end;

595

}

596

597

if(quit_now){

598

errno = EINTR;

599

goto mandos_end;

561

600

}

562

601

563

602

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

564

603

if(af == AF_INET6){

565

to.in6.sin6_family = (uint16_t)af;

604

to.in6.sin6_family = (sa_family_t)af;

566

605

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

567

606

} else { /* IPv4 */

568

607

to.in.sin_family = (sa_family_t)af;

569

608

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

570

609

}

571

610

if(ret < 0 ){

611

int e = errno;

572

612

perror("inet_pton");

573

return -1;

613

errno = e;

614

goto mandos_end;

574

615

}

575

616

if(ret == 0){

617

int e = errno;

576

618

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

577

return -1;

619

errno = e;

620

goto mandos_end;

578

621

}

579

622

if(af == AF_INET6){

580

623

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

587

630

if(if_index == AVAHI_IF_UNSPEC){

588

631

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

589

632

" without a network interface\n");

590

return -1;

633

errno = EINVAL;

634

goto mandos_end;

591

635

}

592

636

/* Set the network interface number as scope */

593

637

to.in6.sin6_scope_id = (uint32_t)if_index;

598

642

-Wunreachable-code */

599

643

}

600

644

645

if(quit_now){

646

errno = EINTR;

647

goto mandos_end;

648

}

649

601

650

if(debug){

602

651

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

603

652

char interface[IF_NAMESIZE];

630

679

}

631

680

}

632

681

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

633

687

if(af == AF_INET6){

634

688

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

635

689

} else {

636

690

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

637

691

}

638

692

if(ret < 0){

693

int e = errno;

639

694

perror("connect");

640

return -1;

695

errno = e;

696

goto mandos_end;

697

}

698

699

if(quit_now){

700

errno = EINTR;

701

goto mandos_end;

641

702

}

642

703

643

704

const char *out = mandos_protocol_version;

647

708

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

648

709

out_size - written));

649

710

if(ret == -1){

711

int e = errno;

650

712

perror("write");

651

retval = -1;

713

errno = e;

652

714

goto mandos_end;

653

715

}

654

716

written += (size_t)ret;

662

724

break;

663

725

}

664

726

}

727

728

if(quit_now){

729

errno = EINTR;

730

goto mandos_end;

731

}

665

732

}

666

733

667

734

if(debug){

668

735

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

669

736

}

670

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

671

743

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

672

744

673

do{

745

if(quit_now){

746

errno = EINTR;

747

goto mandos_end;

748

}

749

750

do {

674

751

ret = gnutls_handshake(session);

752

if(quit_now){

753

errno = EINTR;

754

goto mandos_end;

755

}

675

756

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

676

757

677

758

if(ret != GNUTLS_E_SUCCESS){

679

760

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

680

761

gnutls_perror(ret);

681

762

}

682

retval = -1;

763

errno = EPROTO;

683

764

goto mandos_end;

684

765

}

685

766

691

772

}

692

773

693

774

while(true){

775

776

if(quit_now){

777

errno = EINTR;

778

goto mandos_end;

779

}

780

694

781

buffer_capacity = incbuffer(&buffer, buffer_length,

695

782

buffer_capacity);

696

783

if(buffer_capacity == 0){

784

int e = errno;

697

785

perror("incbuffer");

698

retval = -1;

786

errno = e;

787

goto mandos_end;

788

}

789

790

if(quit_now){

791

errno = EINTR;

699

792

goto mandos_end;

700

793

}

701

794

710

803

case GNUTLS_E_AGAIN:

711

804

break;

712

805

case GNUTLS_E_REHANDSHAKE:

713

do{

806

do {

714

807

ret = gnutls_handshake(session);

808

809

if(quit_now){

810

errno = EINTR;

811

goto mandos_end;

812

}

715

813

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

716

814

if(ret < 0){

717

815

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

718

816

gnutls_perror(ret);

719

retval = -1;

817

errno = EPROTO;

720

818

goto mandos_end;

721

819

}

722

820

break;

723

821

default:

724

822

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

725

823

" encrypted session with Mandos server\n");

726

retval = -1;

727

824

gnutls_bye(session, GNUTLS_SHUT_RDWR);

825

errno = EIO;

728

826

goto mandos_end;

729

827

}

730

828

} else {

736

834

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

737

835

}

738

836

739

gnutls_bye(session, GNUTLS_SHUT_RDWR);

837

if(quit_now){

838

errno = EINTR;

839

goto mandos_end;

840

}

841

842

do {

843

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

844

if(quit_now){

845

errno = EINTR;

846

goto mandos_end;

847

}

848

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

740

849

741

850

if(buffer_length > 0){

851

ssize_t decrypted_buffer_size;

742

852

decrypted_buffer_size = pgp_packet_decrypt(buffer,

743

853

buffer_length,

744

854

&decrypted_buffer);

745

855

if(decrypted_buffer_size >= 0){

856

746

857

written = 0;

747

858

while(written < (size_t) decrypted_buffer_size){

859

if(quit_now){

860

errno = EINTR;

861

goto mandos_end;

862

}

863

748

864

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

749

865

(size_t)decrypted_buffer_size - written,

750

866

stdout);

751

867

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

868

int e = errno;

752

869

if(debug){

753

870

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

754

871

strerror(errno));

755

872

}

756

retval = -1;

757

break;

873

errno = e;

874

goto mandos_end;

758

875

}

759

876

written += (size_t)ret;

760

877

}

761

free(decrypted_buffer);

762

} else {

763

retval = -1;

878

retval = 0;

764

879

}

765

} else {

766

retval = -1;

767

880

}

768

881

769

882

/* Shutdown procedure */

770

883

771

884

mandos_end:

772

free(buffer);

773

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

774

if(ret == -1){

775

perror("close");

885

{

886

int e = errno;

887

free(decrypted_buffer);

888

free(buffer);

889

if(tcp_sd >= 0){

890

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

891

}

892

if(ret == -1){

893

if(e == 0){

894

e = errno;

895

}

896

perror("close");

897

}

898

gnutls_deinit(session);

899

if(quit_now){

900

e = EINTR;

901

retval = -1;

902

}

903

errno = e;

776

904

}

777

gnutls_deinit(session);

778

905

return retval;

779

906

}

780

907

797

924

/* Called whenever a service has been resolved successfully or

798

925

timed out */

799

926

927

if(quit_now){

928

return;

929

}

930

800

931

switch(event){

801

932

default:

802

933

case AVAHI_RESOLVER_FAILURE:

839

970

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

840

971

is removed from the LAN */

841

972

973

if(quit_now){

974

return;

975

}

976

842

977

switch(event){

843

978

default:

844

979

case AVAHI_BROWSER_FAILURE:

854

989

the callback function is called the Avahi server will free the

855

990

resolver for us. */

856

991

857

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

858

protocol, name, type, domain,

859

AVAHI_PROTO_INET6, 0,

860

resolve_callback, NULL)))

992

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

993

name, type, domain, protocol, 0,

994

resolve_callback, NULL) == NULL)

861

995

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

862

996

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

863

997

break;

874

1008

}

875

1009

}

876

1010

877

sig_atomic_t quit_now = 0;

878

879

1011

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

880

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

1012

static void handle_sigterm(int sig){

881

1013

if(quit_now){

882

1014

return;

883

1015

}

884

1016

quit_now = 1;

1017

signal_received = sig;

885

1018

int old_errno = errno;

886

1019

if(mc.simple_poll != NULL){

887

1020

avahi_simple_poll_quit(mc.simple_poll);

889

1022

errno = old_errno;

890

1023

}

891

1024

1025

/*

1026

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

1027

* corresponds to an acceptable network device.

1028

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

1029

*/

1030

int good_interface(const struct dirent *if_entry){

1031

ssize_t ssret;

1032

char *flagname = NULL;

1033

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

1034

if_entry->d_name);

1035

if(ret < 0){

1036

perror("asprintf");

1037

return 0;

1038

}

1039

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

1040

return 0;

1041

}

1042

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

1043

if(flags_fd == -1){

1044

perror("open");

1045

return 0;

1046

}

1047

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

1048

/* read line from flags_fd */

1049

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

1050

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

1051

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

1052

if(flagstring == NULL){

1053

perror("malloc");

1054

close(flags_fd);

1055

return 0;

1056

}

1057

while(to_read > 0){

1058

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

1059

(size_t)to_read));

1060

if(ssret == -1){

1061

perror("read");

1062

free(flagstring);

1063

close(flags_fd);

1064

return 0;

1065

}

1066

to_read -= ssret;

1067

if(ssret == 0){

1068

break;

1069

}

1070

}

1071

close(flags_fd);

1072

intmax_t tmpmax;

1073

char *tmp;

1074

errno = 0;

1075

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

1076

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

1077

and not (isspace(*tmp)))

1078

or tmpmax != (ifreq_flags)tmpmax){

1079

if(debug){

1080

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

1081

flagstring, if_entry->d_name);

1082

}

1083

free(flagstring);

1084

return 0;

1085

}

1086

free(flagstring);

1087

ifreq_flags flags = (ifreq_flags)tmpmax;

1088

/* Reject the loopback device */

1089

if(flags & IFF_LOOPBACK){

1090

if(debug){

1091

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

1092

if_entry->d_name);

1093

}

1094

return 0;

1095

}

1096

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

1097

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

1098

if(debug){

1099

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

1100

if_entry->d_name);

1101

}

1102

return 1;

1103

}

1104

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

1105

if(not (flags & IFF_BROADCAST)){

1106

if(debug){

1107

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

1108

if_entry->d_name);

1109

}

1110

return 0;

1111

}

1112

/* Accept this device */

1113

if(debug){

1114

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

1115

if_entry->d_name);

1116

}

1117

return 1;

1118

}

1119

892

1120

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

893

1121

AvahiSServiceBrowser *sb = NULL;

894

1122

int error;

895

1123

int ret;

896

1124

intmax_t tmpmax;

897

int numchars;

1125

char *tmp;

898

1126

int exitcode = EXIT_SUCCESS;

899

const char *interface = "eth0";

1127

const char *interface = "";

900

1128

struct ifreq network;

901

int sd;

1129

int sd = -1;

1130

bool take_down_interface = false;

902

1131

uid_t uid;

903

1132

gid_t gid;

904

char *connect_to = NULL;

905

1133

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

906

1134

bool tempdir_created = false;

907

1135

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

908

1136

const char *seckey = PATHDIR "/" SECKEY;

909

1137

const char *pubkey = PATHDIR "/" PUBKEY;

910

1138

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" };

915

1139

bool gnutls_initialized = false;

916

1140

bool gpgme_initialized = false;

917

double delay = 2.5;

918

919

struct sigaction old_sigterm_action;

1141

float delay = 2.5f;

1142

1143

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

920

1144

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

921

1145

1146

uid = getuid();

1147

gid = getgid();

1148

1149

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

1150

errno = 0;

1151

ret = setgid(gid);

1152

if(ret == -1){

1153

perror("setgid");

1154

}

1155

1156

/* Lower user privileges (temporarily) */

1157

errno = 0;

1158

ret = seteuid(uid);

1159

if(ret == -1){

1160

perror("seteuid");

1161

}

1162

1163

if(quit_now){

1164

goto end;

1165

}

1166

922

1167

{

923

1168

struct argp_option options[] = {

924

1169

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

953

1198

.arg = "SECONDS",

954

1199

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

955

1200

.group = 2 },

1201

/*

1202

* These reproduce what we would get without ARGP_NO_HELP

1203

*/

1204

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

1205

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

1206

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

1207

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

1208

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

1209

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

956

1210

{ .name = NULL }

957

1211

};

958

1212

959

1213

error_t parse_opt(int key, char *arg,

960

1214

struct argp_state *state){

1215

errno = 0;

961

1216

switch(key){

962

1217

case 128: /* --debug */

963

1218

debug = true;

975

1230

pubkey = arg;

976

1231

break;

977

1232

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

978

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

979

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

980

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

981

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

982

exit(EXIT_FAILURE);

1233

errno = 0;

1234

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

1235

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

1236

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

1237

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

983

1238

}

984

1239

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

985

1240

break;

987

1242

mc.priority = arg;

988

1243

break;

989

1244

case 131: /* --delay */

990

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

991

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

992

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

993

exit(EXIT_FAILURE);

1245

errno = 0;

1246

delay = strtof(arg, &tmp);

1247

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

1248

argp_error(state, "Bad delay");

994

1249

}

995

1250

break;

996

case ARGP_KEY_ARG:

997

argp_usage(state);

998

case ARGP_KEY_END:

1251

/*

1252

* These reproduce what we would get without ARGP_NO_HELP

1253

*/

1254

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

1255

argp_state_help(state, state->out_stream,

1256

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1257

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1258

case -3: /* --usage */

1259

argp_state_help(state, state->out_stream,

1260

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1261

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

1262

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

1263

exit(argp_err_exit_status);

999

1264

break;

1000

1265

default:

1001

1266

return ARGP_ERR_UNKNOWN;

1002

1267

}

1003

return 0;

1268

return errno;

1004

1269

}

1005

1270

1006

1271

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

1007

1272

.args_doc = "",

1008

1273

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

1009

1274

" passwords from a Mandos server" };

1010

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

1011

if(ret == ARGP_ERR_UNKNOWN){

1012

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

1013

exitcode = EXIT_FAILURE;

1275

ret = argp_parse(&argp, argc, argv,

1276

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1277

switch(ret){

1278

case 0:

1279

break;

1280

case ENOMEM:

1281

default:

1282

errno = ret;

1283

perror("argp_parse");

1284

exitcode = EX_OSERR;

1285

goto end;

1286

case EINVAL:

1287

exitcode = EX_USAGE;

1014

1288

goto end;

1015

1289

}

1016

1290

}

1018

1292

if(not debug){

1019

1293

avahi_set_log_function(empty_log);

1020

1294

}

1295

1296

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

1297

struct dirent **direntries;

1298

ret = scandir(sys_class_net, &direntries, good_interface,

1299

alphasort);

1300

if(ret >= 1){

1301

/* Pick the first good interface */

1302

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

1303

if(debug){

1304

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

1305

}

1306

if(interface == NULL){

1307

perror("malloc");

1308

free(direntries);

1309

exitcode = EXIT_FAILURE;

1310

goto end;

1311

}

1312

free(direntries);

1313

} else {

1314

free(direntries);

1315

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

1316

exitcode = EXIT_FAILURE;

1317

goto end;

1318

}

1319

}

1021

1320

1022

1321

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

1023

1322

from the signal handler */

1026

1325

mc.simple_poll = avahi_simple_poll_new();

1027

1326

if(mc.simple_poll == NULL){

1028

1327

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

1029

exitcode = EXIT_FAILURE;

1328

exitcode = EX_UNAVAILABLE;

1030

1329

goto end;

1031

1330

}

1032

1331

1034

1333

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

1035

1334

if(ret == -1){

1036

1335

perror("sigaddset");

1037

exitcode = EXIT_FAILURE;

1336

exitcode = EX_OSERR;

1038

1337

goto end;

1039

1338

}

1040

1339

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

1041

1340

if(ret == -1){

1042

1341

perror("sigaddset");

1043

exitcode = EXIT_FAILURE;

1342

exitcode = EX_OSERR;

1044

1343

goto end;

1045

1344

}

1046

1345

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

1047

1346

if(ret == -1){

1048

1347

perror("sigaddset");

1049

exitcode = EXIT_FAILURE;

1050

goto end;

1051

}

1052

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

1053

if(ret == -1){

1054

perror("sigaction");

1055

exitcode = EXIT_FAILURE;

1056

goto end;

1057

}

1348

exitcode = EX_OSERR;

1349

goto end;

1350

}

1351

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

1352

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

1353

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

1354

*/

1355

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

1356

if(ret == -1){

1357

perror("sigaction");

1358

return EX_OSERR;

1359

}

1360

if(old_sigterm_action.sa_handler != SIG_IGN){

1361

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

1362

if(ret == -1){

1363

perror("sigaction");

1364

exitcode = EX_OSERR;

1365

goto end;

1366

}

1367

}

1368

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

1369

if(ret == -1){

1370

perror("sigaction");

1371

return EX_OSERR;

1372

}

1373

if(old_sigterm_action.sa_handler != SIG_IGN){

1374

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

1375

if(ret == -1){

1376

perror("sigaction");

1377

exitcode = EX_OSERR;

1378

goto end;

1379

}

1380

}

1381

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

1382

if(ret == -1){

1383

perror("sigaction");

1384

return EX_OSERR;

1385

}

1386

if(old_sigterm_action.sa_handler != SIG_IGN){

1387

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

1388

if(ret == -1){

1389

perror("sigaction");

1390

exitcode = EX_OSERR;

1391

goto end;

1392

}

1393

}

1058

1394

1059

1395

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

1060

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

1396

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

1397

if_index = (AvahiIfIndex) if_nametoindex(interface);

1398

if(if_index == 0){

1399

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

1400

exitcode = EX_UNAVAILABLE;

1401

goto end;

1402

}

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1408

/* Re-raise priviliges */

1409

errno = 0;

1410

ret = seteuid(0);

1411

if(ret == -1){

1412

perror("seteuid");

1413

}

1414

1061

1415

#ifdef __linux__

1062

1416

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1063

messages to mess up the prompt */

1417

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

1064

1418

ret = klogctl(8, NULL, 5);

1065

1419

bool restore_loglevel = true;

1066

1420

if(ret == -1){

1072

1426

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1073

1427

if(sd < 0){

1074

1428

perror("socket");

1075

exitcode = EXIT_FAILURE;

1429

exitcode = EX_OSERR;

1076

1430

#ifdef __linux__

1077

1431

if(restore_loglevel){

1078

1432

ret = klogctl(7, NULL, 0);

1081

1435

}

1082

1436

}

1083

1437

#endif /* __linux__ */

1438

/* Lower privileges */

1439

errno = 0;

1440

ret = seteuid(uid);

1441

if(ret == -1){

1442

perror("seteuid");

1443

}

1084

1444

goto end;

1085

1445

}

1086

1446

strcpy(network.ifr_name, interface);

1095

1455

}

1096

1456

}

1097

1457

#endif /* __linux__ */

1098

exitcode = EXIT_FAILURE;

1458

exitcode = EX_OSERR;

1459

/* Lower privileges */

1460

errno = 0;

1461

ret = seteuid(uid);

1462

if(ret == -1){

1463

perror("seteuid");

1464

}

1099

1465

goto end;

1100

1466

}

1101

1467

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

1102

1468

network.ifr_flags |= IFF_UP;

1469

take_down_interface = true;

1103

1470

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

1104

1471

if(ret == -1){

1105

perror("ioctl SIOCSIFFLAGS");

1106

exitcode = EXIT_FAILURE;

1472

take_down_interface = false;

1473

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1474

exitcode = EX_OSERR;

1107

1475

#ifdef __linux__

1108

1476

if(restore_loglevel){

1109

1477

ret = klogctl(7, NULL, 0);

1112

1480

}

1113

1481

}

1114

1482

#endif /* __linux__ */

1483

/* Lower privileges */

1484

errno = 0;

1485

ret = seteuid(uid);

1486

if(ret == -1){

1487

perror("seteuid");

1488

}

1115

1489

goto end;

1116

1490

}

1117

1491

}

1129

1503

perror("nanosleep");

1130

1504

}

1131

1505

}

1132

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

1133

if(ret == -1){

1134

perror("close");

1506

if(not take_down_interface){

1507

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

1508

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

1509

if(ret == -1){

1510

perror("close");

1511

}

1135

1512

}

1136

1513

#ifdef __linux__

1137

1514

if(restore_loglevel){

1142

1519

}

1143

1520

}

1144

1521

#endif /* __linux__ */

1145

}

1146

1147

uid = getuid();

1148

gid = getgid();

1149

1150

errno = 0;

1151

setgid(gid);

1152

if(ret == -1){

1153

perror("setgid");

1154

}

1155

1156

ret = setuid(uid);

1157

if(ret == -1){

1158

perror("setuid");

1522

/* Lower privileges */

1523

errno = 0;

1524

if(take_down_interface){

1525

/* Lower privileges */

1526

ret = seteuid(uid);

1527

if(ret == -1){

1528

perror("seteuid");

1529

}

1530

} else {

1531

/* Lower privileges permanently */

1532

ret = setuid(uid);

1533

if(ret == -1){

1534

perror("setuid");

1535

}

1536

}

1537

}

1538

1539

if(quit_now){

1540

goto end;

1159

1541

}

1160

1542

1161

1543

ret = init_gnutls_global(pubkey, seckey);

1162

1544

if(ret == -1){

1163

1545

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

1164

exitcode = EXIT_FAILURE;

1546

exitcode = EX_UNAVAILABLE;

1165

1547

goto end;

1166

1548

} else {

1167

1549

gnutls_initialized = true;

1168

1550

}

1169

1551

1552

if(quit_now){

1553

goto end;

1554

}

1555

1556

tempdir_created = true;

1170

1557

if(mkdtemp(tempdir) == NULL){

1558

tempdir_created = false;

1171

1559

perror("mkdtemp");

1172

1560

goto end;

1173

1561

}

1174

tempdir_created = true;

1562

1563

if(quit_now){

1564

goto end;

1565

}

1175

1566

1176

1567

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

1177

1568

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

1178

exitcode = EXIT_FAILURE;

1569

exitcode = EX_UNAVAILABLE;

1179

1570

goto end;

1180

1571

} else {

1181

1572

gpgme_initialized = true;

1182

1573

}

1183

1574

1184

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

1185

if_index = (AvahiIfIndex) if_nametoindex(interface);

1186

if(if_index == 0){

1187

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

1188

exitcode = EXIT_FAILURE;

1189

goto end;

1190

}

1575

if(quit_now){

1576

goto end;

1191

1577

}

1192

1578

1193

1579

if(connect_to != NULL){

1196

1582

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

1197

1583

if(address == NULL){

1198

1584

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

1199

exitcode = EXIT_FAILURE;

1200

goto end;

1201

}

1585

exitcode = EX_USAGE;

1586

goto end;

1587

}

1588

1589

if(quit_now){

1590

goto end;

1591

}

1592

1202

1593

uint16_t port;

1203

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

1204

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

1205

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

1594

errno = 0;

1595

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

1596

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

1597

or tmpmax != (uint16_t)tmpmax){

1206

1598

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

1207

exitcode = EXIT_FAILURE;

1208

goto end;

1209

}

1599

exitcode = EX_USAGE;

1600

goto end;

1601

}

1602

1603

if(quit_now){

1604

goto end;

1605

}

1606

1210

1607

port = (uint16_t)tmpmax;

1211

1608

*address = '\0';

1212

1609

address = connect_to;

1217

1614

} else {

1218

1615

af = AF_INET;

1219

1616

}

1617

1618

if(quit_now){

1619

goto end;

1620

}

1621

1220

1622

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

1221

1623

if(ret < 0){

1222

exitcode = EXIT_FAILURE;

1624

switch(errno){

1625

case ENETUNREACH:

1626

case EHOSTDOWN:

1627

case EHOSTUNREACH:

1628

exitcode = EX_NOHOST;

1629

break;

1630

case EINVAL:

1631

exitcode = EX_USAGE;

1632

break;

1633

case EIO:

1634

exitcode = EX_IOERR;

1635

break;

1636

case EPROTO:

1637

exitcode = EX_PROTOCOL;

1638

break;

1639

default:

1640

exitcode = EX_OSERR;

1641

break;

1642

}

1223

1643

} else {

1224

1644

exitcode = EXIT_SUCCESS;

1225

1645

}

1226

1646

goto end;

1227

1647

}

1228

1648

1649

if(quit_now){

1650

goto end;

1651

}

1652

1229

1653

{

1230

1654

AvahiServerConfig config;

1231

1655

/* Do not publish any local Zeroconf records */

1248

1672

if(mc.server == NULL){

1249

1673

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

1250

1674

avahi_strerror(error));

1251

exitcode = EXIT_FAILURE;

1675

exitcode = EX_UNAVAILABLE;

1676

goto end;

1677

}

1678

1679

if(quit_now){

1252

1680

goto end;

1253

1681

}

1254

1682

1255

1683

/* Create the Avahi service browser */

1256

1684

sb = avahi_s_service_browser_new(mc.server, if_index,

1257

AVAHI_PROTO_INET6, "_mandos._tcp",

1685

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1258

1686

NULL, 0, browse_callback, NULL);

1259

1687

if(sb == NULL){

1260

1688

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

1261

1689

avahi_strerror(avahi_server_errno(mc.server)));

1262

exitcode = EXIT_FAILURE;

1690

exitcode = EX_UNAVAILABLE;

1691

goto end;

1692

}

1693

1694

if(quit_now){

1263

1695

goto end;

1264

1696

}

1265

1697

1297

1729

gpgme_release(mc.ctx);

1298

1730

}

1299

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

1300

1764

/* Removes the temp directory used by GPGME */

1301

1765

if(tempdir_created){

1302

1766

DIR *d;

1341

1805

}

1342

1806

}

1343

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

1344

1827

return exitcode;

1345

1828

}