/mandos/release : revision 237.7.453

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

46

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

47

strtof(), abort() */

48

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

49

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

50

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

49

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

50

asprintf(), strncpy(), strsignal()

51

*/

51

52

#include <sys/ioctl.h> /* ioctl */

52

53

#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

53

54

sockaddr_in6, PF_INET6,

57

58

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

58

59

inet_pton(), connect(),

59

60

getnameinfo() */

60

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

61

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

61

62

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

62

63

*/

63

64

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

64

65

strtoimax() */

65

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

66

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

67

EAI_SYSTEM, ENETUNREACH,

68

EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

66

71

program_invocation_short_name */

67

72

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

68

73

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

305

310

return false;

306

311

}

307

312

308

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

313

ret = close(fd);

309

314

if(ret == -1){

310

315

perror_plus("close");

311

316

}

493

498

return plaintext_length;

494

499

}

495

500

501

__attribute__((warn_unused_result, const))

502

static const char *safe_string(const char *str){

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

496

508

__attribute__((warn_unused_result))

497

509

static const char *safer_gnutls_strerror(int value){

498

510

const char *ret = gnutls_strerror(value);

499

if(ret == NULL)

500

ret = "(unknown)";

501

return ret;

511

return safe_string(ret);

502

512

}

503

513

504

514

/* GnuTLS log function callback */

508

518

fprintf_plus(stderr, "GnuTLS: %s", string);

509

519

}

510

520

511

__attribute__((nonnull, warn_unused_result))

521

__attribute__((nonnull(1, 2, 4), warn_unused_result))

512

522

static int init_gnutls_global(const char *pubkeyfilename,

513

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

514

525

mandos_context *mc){

515

526

int ret;

527

unsigned int uret;

516

528

517

529

if(debug){

518

530

fprintf_plus(stderr, "Initializing GnuTLS\n");

519

531

}

520

532

521

ret = gnutls_global_init();

522

if(ret != GNUTLS_E_SUCCESS){

523

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

524

safer_gnutls_strerror(ret));

525

return -1;

526

}

527

528

533

if(debug){

529

534

/* "Use a log level over 10 to enable all debugging options."

530

535

* - GnuTLS manual

538

543

if(ret != GNUTLS_E_SUCCESS){

539

544

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

540

545

safer_gnutls_strerror(ret));

541

gnutls_global_deinit();

542

546

return -1;

543

547

}

544

548

569

573

safer_gnutls_strerror(ret));

570

574

goto globalfail;

571

575

}

572

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

573

if(ret != GNUTLS_E_SUCCESS){

574

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

575

safer_gnutls_strerror(ret));

576

goto globalfail;

577

}

578

576

/* If a Diffie-Hellman parameters file was given, try to use it */

577

if(dhparamsfilename != NULL){

578

gnutls_datum_t params = { .data = NULL, .size = 0 };

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

params_capacity = incbuffer((char **)&params.data,

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

fprintf_plus(stderr, "Failed to parse DH parameters in file"

625

" \"%s\": %s\n", dhparamsfilename,

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

/* Find out the optimal number of DH bits */

635

/* Try to read the private key file */

636

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

buffer_capacity = incbuffer((char **)&buffer.data,

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

/* If successful, use buffer to parse private key */

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

687

if(ret != GNUTLS_E_SUCCESS){

688

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

" a GnuTLS security parameter \"%s\".\n",

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

724

" implies %u DH bits; using that.\n",

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

fprintf_plus(stderr, "Failed to get implied number of DH"

731

" bits for security parameter \"%s\"): %s\n",

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

739

mc->dh_bits);

740

}

741

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

742

if(ret != GNUTLS_E_SUCCESS){

743

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

744

" bits): %s\n", mc->dh_bits,

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

579

749

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

580

750

581

751

return 0;

583

753

globalfail:

584

754

585

755

gnutls_certificate_free_credentials(mc->cred);

586

gnutls_global_deinit();

587

756

gnutls_dh_params_deinit(mc->dh_params);

588

757

return -1;

589

758

}

641

810

/* ignore client certificate if any. */

642

811

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

643

812

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

645

646

813

return 0;

647

814

}

648

815

650

817

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

651

818

__attribute__((unused)) const char *txt){}

652

819

820

/* Set effective uid to 0, return errno */

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

if(seteuid(0) == -1){

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

/* Set effective and real user ID to 0. Return errno. */

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

if(setuid(0) == -1){

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

/* Set effective user ID to unprivileged saved user ID */

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

if(seteuid(uid) == -1){

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

if(setuid(uid) == -1){

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

/* Helper function to add_local_route() and delete_local_route() */

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

char helper[] = "mandos-client-iprouteadddel";

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

" variable not set; cannot run helper\n");

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

if(if_indextoname((unsigned int)if_index, interface) == NULL){

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

898

if(devnull == -1){

899

perror_plus("open(\"/dev/null\", O_RDONLY)");

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

perror_plus("dup2(devnull, STDIN_FILENO)");

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

939

_exit(EX_OSERR);

940

}

941

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

if(fexecve(helper_fd, (char *const [])

963

{ helper, add ? add_arg : delete_arg, (char *)address,

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

pret = waitpid(pid, &status, 0);

982

if(pret == -1 and errno == EINTR and quit_now){

983

int errno_raising = 0;

984

if((errno = raise_privileges()) != 0){

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

if(kill(pid, SIGTERM) == -1){

990

perror_plus("kill");

991

}

992

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

} while(pret == -1 and errno == EINTR);

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

" with status %d\n", WEXITSTATUS(status));

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

" signal %d\n", WTERMSIG(status));

1014

return false;

1015

}

1016

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

fprintf_plus(stderr, "Adding route to %s\n", address);

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

fprintf_plus(stderr, "Removing route to %s\n", address);

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

653

1038

/* Called when a Mandos server is found */

654

1039

__attribute__((nonnull, warn_unused_result))

655

1040

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

666

1051

int retval = -1;

667

1052

gnutls_session_t session;

668

1053

int pf; /* Protocol family */

1054

bool route_added = false;

669

1055

670

1056

errno = 0;

671

1057

693

1079

bool match = false;

694

1080

{

695

1081

char *interface = NULL;

696

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

697

interface))){

1082

while((interface = argz_next(mc->interfaces,

1083

mc->interfaces_size,

1084

interface))){

698

1085

if(if_nametoindex(interface) == (unsigned int)if_index){

699

1086

match = true;

700

1087

break;

729

1116

PRIuMAX "\n", ip, (uintmax_t)port);

730

1117

}

731

1118

732

tcp_sd = socket(pf, SOCK_STREAM, 0);

1119

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

733

1120

if(tcp_sd < 0){

734

1121

int e = errno;

735

1122

perror_plus("socket");

742

1129

goto mandos_end;

743

1130

}

744

1131

745

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

746

1132

if(af == AF_INET6){

747

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

748

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

1133

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1134

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1135

ret = inet_pton(af, ip, &to6->sin6_addr);

749

1136

} else { /* IPv4 */

750

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

751

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

1137

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1138

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1139

ret = inet_pton(af, ip, &to4->sin_addr);

752

1140

}

753

1141

if(ret < 0 ){

754

1142

int e = errno;

824

1212

goto mandos_end;

825

1213

}

826

1214

827

if(af == AF_INET6){

828

ret = connect(tcp_sd, (struct sockaddr *)&to,

829

sizeof(struct sockaddr_in6));

830

} else {

831

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

832

sizeof(struct sockaddr_in));

833

}

834

if(ret < 0){

835

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

836

int e = errno;

837

perror_plus("connect");

838

errno = e;

839

}

840

goto mandos_end;

841

}

842

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

1215

while(true){

1216

if(af == AF_INET6){

1217

ret = connect(tcp_sd, (struct sockaddr *)&to,

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1234

& 0xFFFF0000L) != 0xA9FE0000L))){

1235

/* Work around Avahi bug - Avahi does not announce link-local

1236

addresses if it has a global address, so local hosts with

1237

*only* a link-local address (e.g. Mandos clients) cannot

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

with an explicit route added with the server's address.

1241

1242

Avahi bug reference:

1243

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

846

1270

}

847

1271

848

1272

const char *out = mandos_protocol_version;

1002

1426

&decrypted_buffer, mc);

1003

1427

if(decrypted_buffer_size >= 0){

1004

1428

1429

clearerr(stdout);

1005

1430

written = 0;

1006

1431

while(written < (size_t) decrypted_buffer_size){

1007

1432

if(quit_now){

1023

1448

}

1024

1449

written += (size_t)ret;

1025

1450

}

1451

ret = fflush(stdout);

1452

if(ret != 0){

1453

int e = errno;

1454

if(debug){

1455

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

1456

strerror(errno));

1457

}

1458

errno = e;

1459

goto mandos_end;

1460

}

1026

1461

retval = 0;

1027

1462

}

1028

1463

}

1031

1466

1032

1467

mandos_end:

1033

1468

{

1469

if(route_added){

1470

if(not delete_local_route(ip, if_index)){

1471

fprintf_plus(stderr, "Failed to delete local route to %s on"

1472

" interface %d", ip, if_index);

1473

}

1474

}

1034

1475

int e = errno;

1035

1476

free(decrypted_buffer);

1036

1477

free(buffer);

1037

1478

if(tcp_sd >= 0){

1038

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

1479

ret = close(tcp_sd);

1039

1480

}

1040

1481

if(ret == -1){

1041

1482

if(e == 0){

1053

1494

return retval;

1054

1495

}

1055

1496

1056

__attribute__((nonnull))

1057

1497

static void resolve_callback(AvahiSServiceResolver *r,

1058

1498

AvahiIfIndex interface,

1059

1499

AvahiProtocol proto,

1196

1636

__attribute__((nonnull, warn_unused_result))

1197

1637

bool get_flags(const char *ifname, struct ifreq *ifr){

1198

1638

int ret;

1199

error_t ret_errno;

1639

int old_errno;

1200

1640

1201

1641

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1202

1642

if(s < 0){

1203

ret_errno = errno;

1643

old_errno = errno;

1204

1644

perror_plus("socket");

1205

errno = ret_errno;

1645

errno = old_errno;

1206

1646

return false;

1207

1647

}

1208

strcpy(ifr->ifr_name, ifname);

1648

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1649

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1209

1650

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1210

1651

if(ret == -1){

1211

1652

if(debug){

1212

ret_errno = errno;

1653

old_errno = errno;

1213

1654

perror_plus("ioctl SIOCGIFFLAGS");

1214

errno = ret_errno;

1655

errno = old_errno;

1215

1656

}

1216

1657

return false;

1217

1658

}

1462

1903

}

1463

1904

}

1464

1905

1465

/* Set effective uid to 0, return errno */

1466

__attribute__((warn_unused_result))

1467

error_t raise_privileges(void){

1468

error_t old_errno = errno;

1469

error_t ret_errno = 0;

1470

if(seteuid(0) == -1){

1471

ret_errno = errno;

1472

}

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

1477

/* Set effective and real user ID to 0. Return errno. */

1478

__attribute__((warn_unused_result))

1479

error_t raise_privileges_permanently(void){

1480

error_t old_errno = errno;

1481

error_t ret_errno = raise_privileges();

1482

if(ret_errno != 0){

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

if(setuid(0) == -1){

1487

ret_errno = errno;

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

/* Set effective user ID to unprivileged saved user ID */

1494

__attribute__((warn_unused_result))

1495

error_t lower_privileges(void){

1496

error_t old_errno = errno;

1497

error_t ret_errno = 0;

1498

if(seteuid(uid) == -1){

1499

ret_errno = errno;

1500

}

1501

errno = old_errno;

1502

return ret_errno;

1503

}

1504

1505

/* Lower privileges permanently */

1506

__attribute__((warn_unused_result))

1507

error_t lower_privileges_permanently(void){

1508

error_t old_errno = errno;

1509

error_t ret_errno = 0;

1510

if(setuid(uid) == -1){

1511

ret_errno = errno;

1512

}

1513

errno = old_errno;

1514

return ret_errno;

1515

}

1516

1517

1906

__attribute__((nonnull))

1518

1907

void run_network_hooks(const char *mode, const char *interface,

1519

1908

const float delay){

1520

1909

struct dirent **direntries = NULL;

1521

1910

if(hookdir_fd == -1){

1522

hookdir_fd = open(hookdir, O_RDONLY);

1911

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1912

| O_CLOEXEC);

1523

1913

if(hookdir_fd == -1){

1524

1914

if(errno == ENOENT){

1525

1915

if(debug){

1532

1922

return;

1533

1923

}

1534

1924

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

1537

1925

int numhooks = scandirat(hookdir_fd, ".", &direntries,

1538

1926

runnable_hook, alphasort);

1539

#else /* not __GLIBC_PREREQ(2, 15) */

1540

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1541

alphasort);

1542

#endif /* not __GLIBC_PREREQ(2, 15) */

1543

#else /* not __GLIBC__ */

1544

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1545

alphasort);

1546

#endif /* not __GLIBC__ */

1547

1927

if(numhooks == -1){

1548

1928

perror_plus("scandir");

1549

1929

return;

1550

1930

}

1551

1931

struct dirent *direntry;

1552

1932

int ret;

1553

int devnull = open("/dev/null", O_RDONLY);

1933

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1934

if(devnull == -1){

1935

perror_plus("open(\"/dev/null\", O_RDONLY)");

1936

return;

1937

}

1554

1938

for(int i = 0; i < numhooks; i++){

1555

1939

direntry = direntries[i];

1556

1940

if(debug){

1580

1964

perror_plus("setgroups");

1581

1965

_exit(EX_NOPERM);

1582

1966

}

1583

ret = dup2(devnull, STDIN_FILENO);

1584

if(ret == -1){

1585

perror_plus("dup2(devnull, STDIN_FILENO)");

1586

_exit(EX_OSERR);

1587

}

1588

ret = close(devnull);

1589

if(ret == -1){

1590

perror_plus("close");

1591

_exit(EX_OSERR);

1592

}

1593

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1594

if(ret == -1){

1595

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1596

_exit(EX_OSERR);

1597

}

1598

1967

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1599

1968

if(ret == -1){

1600

1969

perror_plus("setenv");

1635

2004

_exit(EX_OSERR);

1636

2005

}

1637

2006

}

1638

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

2007

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2008

direntry->d_name,

2009

O_RDONLY));

1639

2010

if(hook_fd == -1){

1640

2011

perror_plus("openat");

1641

2012

_exit(EXIT_FAILURE);

1642

2013

}

1643

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2014

if(close(hookdir_fd) == -1){

1644

2015

perror_plus("close");

1645

2016

_exit(EXIT_FAILURE);

1646

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

perror_plus("dup2(devnull, STDIN_FILENO)");

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2031

_exit(EX_OSERR);

2032

}

1647

2033

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

1648

2034

environ) == -1){

1649

2035

perror_plus("fexecve");

1650

2036

_exit(EXIT_FAILURE);

1651

2037

}

1652

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

1653

2044

int status;

1654

2045

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1655

2046

perror_plus("waitpid");

1684

2075

free(direntry);

1685

2076

}

1686

2077

free(direntries);

1687

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2078

if(close(hookdir_fd) == -1){

1688

2079

perror_plus("close");

1689

2080

} else {

1690

2081

hookdir_fd = -1;

1693

2084

}

1694

2085

1695

2086

__attribute__((nonnull, warn_unused_result))

1696

error_t bring_up_interface(const char *const interface,

1697

const float delay){

1698

error_t old_errno = errno;

2087

int bring_up_interface(const char *const interface,

2088

const float delay){

2089

int old_errno = errno;

1699

2090

int ret;

1700

2091

struct ifreq network;

1701

2092

unsigned int if_index = if_nametoindex(interface);

1711

2102

}

1712

2103

1713

2104

if(not interface_is_up(interface)){

1714

error_t ret_errno = 0, ioctl_errno = 0;

2105

int ret_errno = 0;

2106

int ioctl_errno = 0;

1715

2107

if(not get_flags(interface, &network)){

1716

2108

ret_errno = errno;

1717

2109

fprintf_plus(stderr, "Failed to get flags for interface "

1730

2122

}

1731

2123

1732

2124

if(quit_now){

1733

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

2125

ret = close(sd);

1734

2126

if(ret == -1){

1735

2127

perror_plus("close");

1736

2128

}

1786

2178

}

1787

2179

1788

2180

/* Close the socket */

1789

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

2181

ret = close(sd);

1790

2182

if(ret == -1){

1791

2183

perror_plus("close");

1792

2184

}

1804

2196

1805

2197

/* Sleep checking until interface is running.

1806

2198

Check every 0.25s, up to total time of delay */

1807

for(int i=0; i < delay * 4; i++){

2199

for(int i = 0; i < delay * 4; i++){

1808

2200

if(interface_is_running(interface)){

1809

2201

break;

1810

2202

}

1820

2212

}

1821

2213

1822

2214

__attribute__((nonnull, warn_unused_result))

1823

error_t take_down_interface(const char *const interface){

1824

error_t old_errno = errno;

2215

int take_down_interface(const char *const interface){

2216

int old_errno = errno;

1825

2217

struct ifreq network;

1826

2218

unsigned int if_index = if_nametoindex(interface);

1827

2219

if(if_index == 0){

1830

2222

return ENXIO;

1831

2223

}

1832

2224

if(interface_is_up(interface)){

1833

error_t ret_errno = 0, ioctl_errno = 0;

2225

int ret_errno = 0;

2226

int ioctl_errno = 0;

1834

2227

if(not get_flags(interface, &network) and debug){

1835

2228

ret_errno = errno;

1836

2229

fprintf_plus(stderr, "Failed to get flags for interface "

1874

2267

}

1875

2268

1876

2269

/* Close the socket */

1877

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

2270

int ret = close(sd);

1878

2271

if(ret == -1){

1879

2272

perror_plus("close");

1880

2273

}

1895

2288

}

1896

2289

1897

2290

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

1898

mandos_context mc = { .server = NULL, .dh_bits = 1024,

1899

.priority = "SECURE256:!CTYPE-X.509:"

1900

"+CTYPE-OPENPGP", .current_server = NULL,

1901

.interfaces = NULL, .interfaces_size = 0 };

2291

mandos_context mc = { .server = NULL, .dh_bits = 0,

2292

.priority = "SECURE256:!CTYPE-X.509"

2293

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

1902

2296

AvahiSServiceBrowser *sb = NULL;

1903

2297

error_t ret_errno;

1904

2298

int ret;

1913

2307

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1914

2308

const char *seckey = PATHDIR "/" SECKEY;

1915

2309

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

1916

2311

char *interfaces_hooks = NULL;

1917

2312

1918

2313

bool gnutls_initialized = false;

1971

2366

.doc = "Bit length of the prime number used in the"

1972

2367

" Diffie-Hellman key exchange",

1973

2368

.group = 2 },

2369

{ .name = "dh-params", .key = 134,

2370

.arg = "FILE",

2371

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

1974

2374

{ .name = "priority", .key = 130,

1975

2375

.arg = "STRING",

1976

2376

.doc = "GnuTLS priority string for the TLS handshake",

2031

2431

}

2032

2432

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

2033

2433

break;

2434

case 134: /* --dh-params */

2435

dh_params_file = arg;

2436

break;

2034

2437

case 130: /* --priority */

2035

2438

mc.priority = arg;

2036

2439

break;

2076

2479

.args_doc = "",

2077

2480

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

2078

2481

" passwords from a Mandos server" };

2079

ret = argp_parse(&argp, argc, argv,

2080

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2081

switch(ret){

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

2082

2485

case 0:

2083

2486

break;

2084

2487

case ENOMEM:

2085

2488

default:

2086

errno = ret;

2489

errno = ret_errno;

2087

2490

perror_plus("argp_parse");

2088

2491

exitcode = EX_OSERR;

2089

2492

goto end;

2092

2495

goto end;

2093

2496

}

2094

2497

}

2095

2498

2096

2499

{

2097

2500

/* Work around Debian bug #633582:

2098

<http://bugs.debian.org/633582> */

2501

<https://bugs.debian.org/633582> */

2099

2502

2100

2503

/* Re-raise privileges */

2101

ret_errno = raise_privileges();

2102

if(ret_errno != 0){

2103

errno = ret_errno;

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2104

2507

perror_plus("Failed to raise privileges");

2105

2508

} else {

2106

2509

struct stat st;

2122

2525

}

2123

2526

}

2124

2527

}

2125

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

close(seckey_fd);

2126

2529

}

2127

2530

}

2128

2531

2129

2532

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2130

2533

int pubkey_fd = open(pubkey, O_RDONLY);

2131

2534

if(pubkey_fd == -1){

2143

2546

}

2144

2547

}

2145

2548

}

2146

TEMP_FAILURE_RETRY(close(pubkey_fd));

2147

}

2148

}

2149

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

and st.st_uid == 0 and st.st_gid == 0){

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

2150

2575

/* Lower privileges */

2151

ret_errno = lower_privileges();

2152

if(ret_errno != 0){

2153

errno = ret_errno;

2576

ret = lower_privileges();

2577

if(ret != 0){

2578

errno = ret;

2154

2579

perror_plus("Failed to lower privileges");

2155

2580

}

2156

2581

}

2326

2751

errno = bring_up_interface(interface, delay);

2327

2752

if(not interface_was_up){

2328

2753

if(errno != 0){

2329

perror_plus("Failed to bring up interface");

2754

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2755

" %s\n", interface, strerror(errno));

2330

2756

} else {

2331

2757

errno = argz_add(&interfaces_to_take_down,

2332

2758

&interfaces_to_take_down_size,

2355

2781

goto end;

2356

2782

}

2357

2783

2358

ret = init_gnutls_global(pubkey, seckey, &mc);

2784

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2359

2785

if(ret == -1){

2360

2786

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

2361

2787

exitcode = EX_UNAVAILABLE;

2483

2909

2484

2910

/* Allocate a new server */

2485

2911

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2486

&config, NULL, NULL, &ret_errno);

2912

&config, NULL, NULL, &ret);

2487

2913

2488

2914

/* Free the Avahi configuration data */

2489

2915

avahi_server_config_free(&config);

2492

2918

/* Check if creating the Avahi server object succeeded */

2493

2919

if(mc.server == NULL){

2494

2920

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

2495

avahi_strerror(ret_errno));

2921

avahi_strerror(ret));

2496

2922

exitcode = EX_UNAVAILABLE;

2497

2923

goto end;

2498

2924

}

2533

2959

end:

2534

2960

2535

2961

if(debug){

2536

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2962

if(signal_received){

2963

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

2964

argv[0], signal_received,

2965

strsignal(signal_received));

2966

} else {

2967

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2968

}

2537

2969

}

2538

2970

2539

2971

/* Cleanup things */

2550

2982

2551

2983

if(gnutls_initialized){

2552

2984

gnutls_certificate_free_credentials(mc.cred);

2553

gnutls_global_deinit();

2554

2985

gnutls_dh_params_deinit(mc.dh_params);

2555

2986

}

2556

2987

2579

3010

2580

3011

/* Re-raise privileges */

2581

3012

{

2582

ret_errno = raise_privileges();

2583

if(ret_errno != 0){

2584

errno = ret_errno;

3013

ret = raise_privileges();

3014

if(ret != 0){

3015

errno = ret;

2585

3016

perror_plus("Failed to raise privileges");

2586

3017

} else {

2587

3018

2592

3023

/* Take down the network interfaces which were brought up */

2593

3024

{

2594

3025

char *interface = NULL;

2595

while((interface=argz_next(interfaces_to_take_down,

2596

interfaces_to_take_down_size,

2597

interface))){

2598

ret_errno = take_down_interface(interface);

2599

if(ret_errno != 0){

2600

errno = ret_errno;

3026

while((interface = argz_next(interfaces_to_take_down,

3027

interfaces_to_take_down_size,

3028

interface))){

3029

ret = take_down_interface(interface);

3030

if(ret != 0){

3031

errno = ret;

2601

3032

perror_plus("Failed to take down interface");

2602

3033

}

2603

3034

}

2608

3039

}

2609

3040

}

2610

3041

2611

ret_errno = lower_privileges_permanently();

2612

if(ret_errno != 0){

2613

errno = ret_errno;

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

2614

3045

perror_plus("Failed to lower privileges permanently");

2615

3046

}

2616

3047

}

2618

3049

free(interfaces_to_take_down);

2619

3050

free(interfaces_hooks);

2620

3051

3052

void clean_dir_at(int base, const char * const dirname,

3053

uintmax_t level){

3054

struct dirent **direntries = NULL;

3055

int dret;

3056

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3057

O_RDONLY

3058

| O_NOFOLLOW

3059

| O_DIRECTORY

3060

| O_PATH));

3061

if(dir_fd == -1){

3062

perror_plus("open");

3063

}

3064

int numentries = scandirat(dir_fd, ".", &direntries,

3065

notdotentries, alphasort);

3066

if(numentries >= 0){

3067

for(int i = 0; i < numentries; i++){

3068

if(debug){

3069

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3070

dirname, direntries[i]->d_name);

3071

}

3072

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3073

if(dret == -1){

3074

if(errno == EISDIR){

3075

dret = unlinkat(dir_fd, direntries[i]->d_name,

3076

AT_REMOVEDIR);

3077

}

3078

if((dret == -1) and (errno == ENOTEMPTY)

3079

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3080

== 0) and (level == 0)){

3081

/* Recurse only in this special case */

3082

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3083

dret = 0;

3084

}

3085

if(dret == -1){

3086

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3087

direntries[i]->d_name, strerror(errno));

3088

}

3089

}

3090

free(direntries[i]);

3091

}

3092

3093

/* need to clean even if 0 because man page doesn't specify */

3094

free(direntries);

3095

if(numentries == -1){

3096

perror_plus("scandirat");

3097

}

3098

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3099

if(dret == -1 and errno != ENOENT){

3100

perror_plus("rmdir");

3101

}

3102

} else {

3103

perror_plus("scandirat");

3104

}

3105

close(dir_fd);

3106

}

3107

2621

3108

/* Removes the GPGME temp directory and all files inside */

2622

3109

if(tempdir != NULL){

2623

struct dirent **direntries = NULL;

2624

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |

2625

O_NOFOLLOW));

2626

if(tempdir_fd == -1){

2627

perror_plus("open");

2628

} else {

2629

#ifdef __GLIBC__

2630

#if __GLIBC_PREREQ(2, 15)

2631

int numentries = scandirat(tempdir_fd, ".", &direntries,

2632

notdotentries, alphasort);

2633

#else /* not __GLIBC_PREREQ(2, 15) */

2634

int numentries = scandir(tempdir, &direntries, notdotentries,

2635

alphasort);

2636

#endif /* not __GLIBC_PREREQ(2, 15) */

2637

#else /* not __GLIBC__ */

2638

int numentries = scandir(tempdir, &direntries, notdotentries,

2639

alphasort);

2640

#endif /* not __GLIBC__ */

2641

if(numentries >= 0){

2642

for(int i = 0; i < numentries; i++){

2643

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2644

if(ret == -1){

2645

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2646

" \"%s\", 0): %s\n", tempdir,

2647

direntries[i]->d_name, strerror(errno));

2648

}

2649

free(direntries[i]);

2650

}

2651

2652

/* need to clean even if 0 because man page doesn't specify */

2653

free(direntries);

2654

if(numentries == -1){

2655

perror_plus("scandir");

2656

}

2657

ret = rmdir(tempdir);

2658

if(ret == -1 and errno != ENOENT){

2659

perror_plus("rmdir");

2660

}

2661

}

2662

TEMP_FAILURE_RETRY(close(tempdir_fd));

2663

}

3110

clean_dir_at(-1, tempdir, 0);

2664

3111

}

2665

3112

2666

3113

if(quit_now){