/mandos/trunk : revision 237.4.52

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> /* strcmp(), strlen(), strerror(),

50

asprintf(), strncpy(), strsignal()

51

*/

49

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

50

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

52

51

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

53

52

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

54

53

sockaddr_in6, PF_INET6,

58

57

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

59

58

inet_pton(), connect(),

60

59

getnameinfo() */

61

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

60

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

62

61

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

63

62

*/

64

63

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

65

64

strtoimax() */

66

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

67

EAI_SYSTEM, ENETUNREACH,

68

EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

65

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

71

66

program_invocation_short_name */

72

67

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

73

68

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

310

305

return false;

311

306

}

312

307

313

ret = close(fd);

308

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

314

309

if(ret == -1){

315

310

perror_plus("close");

316

311

}

498

493

return plaintext_length;

499

494

}

500

495

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

508

496

__attribute__((warn_unused_result))

509

497

static const char *safer_gnutls_strerror(int value){

510

498

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

499

if(ret == NULL)

500

ret = "(unknown)";

501

return ret;

512

502

}

513

503

514

504

/* GnuTLS log function callback */

518

508

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

519

509

}

520

510

521

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

511

__attribute__((nonnull, warn_unused_result))

522

512

static int init_gnutls_global(const char *pubkeyfilename,

523

513

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

514

mandos_context *mc){

526

515

int ret;

527

unsigned int uret;

528

516

529

517

if(debug){

530

518

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

531

519

}

532

520

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

533

528

if(debug){

534

529

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

535

530

* - GnuTLS manual

543

538

if(ret != GNUTLS_E_SUCCESS){

544

539

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

545

540

safer_gnutls_strerror(ret));

541

gnutls_global_deinit();

546

542

return -1;

547

543

}

548

544

573

569

safer_gnutls_strerror(ret));

574

570

goto globalfail;

575

571

}

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

} while(false);

630

}

631

if(dhparamsfilename == NULL){

632

if(mc->dh_bits == 0){

633

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

634

/* Try to read the private key file */

635

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

636

do {

637

int secfile = open(seckeyfilename, O_RDONLY);

638

if(secfile == -1){

639

perror_plus("open");

640

break;

641

}

642

size_t buffer_capacity = 0;

643

while(true){

644

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

645

(size_t)buffer.size,

646

(size_t)buffer_capacity);

647

if(buffer_capacity == 0){

648

perror_plus("incbuffer");

649

free(buffer.data);

650

buffer.data = NULL;

651

break;

652

}

653

ssize_t bytes_read = read(secfile,

654

buffer.data + buffer.size,

655

BUFFER_SIZE);

656

/* EOF */

657

if(bytes_read == 0){

658

break;

659

}

660

/* check bytes_read for failure */

661

if(bytes_read < 0){

662

perror_plus("read");

663

free(buffer.data);

664

buffer.data = NULL;

665

break;

666

}

667

buffer.size += (unsigned int)bytes_read;

668

}

669

close(secfile);

670

} while(false);

671

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

672

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

673

if(buffer.data != NULL){

674

{

675

gnutls_openpgp_privkey_t privkey = NULL;

676

ret = gnutls_openpgp_privkey_init(&privkey);

677

if(ret != GNUTLS_E_SUCCESS){

678

fprintf_plus(stderr, "Error initializing OpenPGP key"

679

" structure: %s",

680

safer_gnutls_strerror(ret));

681

free(buffer.data);

682

buffer.data = NULL;

683

} else {

684

ret = gnutls_openpgp_privkey_import

685

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

686

if(ret != GNUTLS_E_SUCCESS){

687

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

688

safer_gnutls_strerror(ret));

689

privkey = NULL;

690

}

691

free(buffer.data);

692

buffer.data = NULL;

693

if(privkey != NULL){

694

/* Use private key to suggest an appropriate

695

sec_param */

696

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

697

gnutls_openpgp_privkey_deinit(privkey);

698

if(debug){

699

fprintf_plus(stderr, "This OpenPGP key implies using"

700

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

701

safe_string(gnutls_sec_param_get_name

702

(sec_param)));

703

}

704

}

705

}

706

}

707

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

708

/* Err on the side of caution */

709

sec_param = GNUTLS_SEC_PARAM_ULTRA;

710

if(debug){

711

fprintf_plus(stderr, "Falling back to security parameter"

712

" \"%s\"\n",

713

safe_string(gnutls_sec_param_get_name

714

(sec_param)));

715

}

716

}

717

}

718

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

719

if(uret != 0){

720

mc->dh_bits = uret;

721

if(debug){

722

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

723

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

724

safe_string(gnutls_sec_param_get_name

725

(sec_param)),

726

mc->dh_bits);

727

}

728

} else {

729

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

730

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

731

safe_string(gnutls_sec_param_get_name

732

(sec_param)),

733

safer_gnutls_strerror(ret));

734

goto globalfail;

735

}

736

} else if(debug){

737

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

738

mc->dh_bits);

739

}

740

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

741

if(ret != GNUTLS_E_SUCCESS){

742

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

743

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

744

safer_gnutls_strerror(ret));

745

goto globalfail;

746

}

747

}

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

748

579

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

749

580

750

581

return 0;

752

583

globalfail:

753

584

754

585

gnutls_certificate_free_credentials(mc->cred);

586

gnutls_global_deinit();

755

587

gnutls_dh_params_deinit(mc->dh_params);

756

588

return -1;

757

589

}

809

641

/* ignore client certificate if any. */

810

642

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

811

643

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

645

812

646

return 0;

813

647

}

814

648

816

650

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

817

651

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

818

652

819

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

820

__attribute__((warn_unused_result))

821

int raise_privileges(void){

822

int old_errno = errno;

823

int ret = 0;

824

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

825

ret = errno;

826

}

827

errno = old_errno;

828

return ret;

829

}

830

831

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

832

__attribute__((warn_unused_result))

833

int raise_privileges_permanently(void){

834

int old_errno = errno;

835

int ret = raise_privileges();

836

if(ret != 0){

837

errno = old_errno;

838

return ret;

839

}

840

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

841

ret = errno;

842

}

843

errno = old_errno;

844

return ret;

845

}

846

847

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

848

__attribute__((warn_unused_result))

849

int lower_privileges(void){

850

int old_errno = errno;

851

int ret = 0;

852

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

853

ret = errno;

854

}

855

errno = old_errno;

856

return ret;

857

}

858

859

/* Lower privileges permanently */

860

__attribute__((warn_unused_result))

861

int lower_privileges_permanently(void){

862

int old_errno = errno;

863

int ret = 0;

864

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

865

ret = errno;

866

}

867

errno = old_errno;

868

return ret;

869

}

870

871

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

872

__attribute__((nonnull, warn_unused_result))

873

static bool add_delete_local_route(const bool add,

874

const char *address,

875

AvahiIfIndex if_index){

876

int ret;

877

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

878

char add_arg[] = "add";

879

char delete_arg[] = "delete";

880

char debug_flag[] = "--debug";

881

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

882

if(pluginhelperdir == NULL){

883

if(debug){

884

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

885

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

886

}

887

return false;

888

}

889

890

char interface[IF_NAMESIZE];

891

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

892

perror_plus("if_indextoname");

893

return false;

894

}

895

896

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

897

if(devnull == -1){

898

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

899

return false;

900

}

901

pid_t pid = fork();

902

if(pid == 0){

903

/* Child */

904

/* Raise privileges */

905

errno = raise_privileges_permanently();

906

if(errno != 0){

907

perror_plus("Failed to raise privileges");

908

/* _exit(EX_NOPERM); */

909

} else {

910

/* Set group */

911

errno = 0;

912

ret = setgid(0);

913

if(ret == -1){

914

perror_plus("setgid");

915

_exit(EX_NOPERM);

916

}

917

/* Reset supplementary groups */

918

errno = 0;

919

ret = setgroups(0, NULL);

920

if(ret == -1){

921

perror_plus("setgroups");

922

_exit(EX_NOPERM);

923

}

924

}

925

ret = dup2(devnull, STDIN_FILENO);

926

if(ret == -1){

927

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

928

_exit(EX_OSERR);

929

}

930

ret = close(devnull);

931

if(ret == -1){

932

perror_plus("close");

933

_exit(EX_OSERR);

934

}

935

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

936

if(ret == -1){

937

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

938

_exit(EX_OSERR);

939

}

940

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

941

O_RDONLY

942

| O_DIRECTORY

943

| O_PATH

944

| O_CLOEXEC));

945

if(helperdir_fd == -1){

946

perror_plus("open");

947

_exit(EX_UNAVAILABLE);

948

}

949

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

950

helper, O_RDONLY));

951

if(helper_fd == -1){

952

perror_plus("openat");

953

close(helperdir_fd);

954

_exit(EX_UNAVAILABLE);

955

}

956

close(helperdir_fd);

957

#ifdef __GNUC__

958

#pragma GCC diagnostic push

959

#pragma GCC diagnostic ignored "-Wcast-qual"

960

#endif

961

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

962

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

963

interface, debug ? debug_flag : NULL, NULL },

964

environ) == -1){

965

#ifdef __GNUC__

966

#pragma GCC diagnostic pop

967

#endif

968

perror_plus("fexecve");

969

_exit(EXIT_FAILURE);

970

}

971

}

972

if(pid == -1){

973

perror_plus("fork");

974

return false;

975

}

976

int status;

977

pid_t pret = -1;

978

errno = 0;

979

do {

980

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

981

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

982

int errno_raising = 0;

983

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

984

errno_raising = errno;

985

perror_plus("Failed to raise privileges in order to"

986

" kill helper program");

987

}

988

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

989

perror_plus("kill");

990

}

991

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

992

perror_plus("Failed to lower privileges after killing"

993

" helper program");

994

}

995

return false;

996

}

997

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

998

if(pret == -1){

999

perror_plus("waitpid");

1000

return false;

1001

}

1002

if(WIFEXITED(status)){

1003

if(WEXITSTATUS(status) != 0){

1004

fprintf_plus(stderr, "Error: iprouteadddel exited"

1005

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

1006

return false;

1007

}

1008

return true;

1009

}

1010

if(WIFSIGNALED(status)){

1011

fprintf_plus(stderr, "Error: iprouteadddel died by"

1012

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

1013

return false;

1014

}

1015

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

1016

return false;

1017

}

1018

1019

__attribute__((nonnull, warn_unused_result))

1020

static bool add_local_route(const char *address,

1021

AvahiIfIndex if_index){

1022

if(debug){

1023

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

1024

}

1025

return add_delete_local_route(true, address, if_index);

1026

}

1027

1028

__attribute__((nonnull, warn_unused_result))

1029

static bool delete_local_route(const char *address,

1030

AvahiIfIndex if_index){

1031

if(debug){

1032

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

1033

}

1034

return add_delete_local_route(false, address, if_index);

1035

}

1036

1037

653

/* Called when a Mandos server is found */

1038

654

__attribute__((nonnull, warn_unused_result))

1039

655

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

1050

666

int retval = -1;

1051

667

gnutls_session_t session;

1052

668

int pf; /* Protocol family */

1053

bool route_added = false;

1054

669

1055

670

errno = 0;

1056

671

1114

729

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

1115

730

}

1116

731

1117

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

732

tcp_sd = socket(pf, SOCK_STREAM, 0);

1118

733

if(tcp_sd < 0){

1119

734

int e = errno;

1120

735

perror_plus("socket");

1127

742

goto mandos_end;

1128

743

}

1129

744

745

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

1130

746

if(af == AF_INET6){

1131

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

1132

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

1133

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

747

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

748

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

1134

749

} else { /* IPv4 */

1135

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

1136

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

1137

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

750

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

751

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

1138

752

}

1139

753

if(ret < 0 ){

1140

754

int e = errno;

1210

824

goto mandos_end;

1211

825

}

1212

826

1213

while(true){

1214

if(af == AF_INET6){

1215

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

1216

sizeof(struct sockaddr_in6));

1217

} else {

1218

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

1219

sizeof(struct sockaddr_in));

1220

}

1221

if(ret < 0){

1222

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

1223

and if_index != AVAHI_IF_UNSPEC

1224

and connect_to == NULL

1225

and not route_added and

1226

((af == AF_INET6 and not

1227

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1228

&to)->sin6_addr)))

1229

or (af == AF_INET and

1230

/* Not a a IPv4LL address */

1231

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

1232

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

1233

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

1234

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

1235

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

1236

connect to a Mandos server announced by Avahi on a server

1237

host with a global address. Work around this by retrying

1238

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

1239

1240

Avahi bug reference:

1241

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

1242

https://bugs.debian.org/587961

1243

*/

1244

if(debug){

1245

fprintf_plus(stderr, "Mandos server unreachable, trying"

1246

" direct route\n");

1247

}

1248

int e = errno;

1249

route_added = add_local_route(ip, if_index);

1250

if(route_added){

1251

continue;

1252

}

1253

errno = e;

1254

}

1255

if(errno != ECONNREFUSED or debug){

1256

int e = errno;

1257

perror_plus("connect");

1258

errno = e;

1259

}

1260

goto mandos_end;

1261

}

1262

1263

if(quit_now){

1264

errno = EINTR;

1265

goto mandos_end;

1266

}

1267

break;

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;

1268

846

}

1269

847

1270

848

const char *out = mandos_protocol_version;

1424

1002

&decrypted_buffer, mc);

1425

1003

if(decrypted_buffer_size >= 0){

1426

1004

1427

clearerr(stdout);

1428

1005

written = 0;

1429

1006

while(written < (size_t) decrypted_buffer_size){

1430

1007

if(quit_now){

1446

1023

}

1447

1024

written += (size_t)ret;

1448

1025

}

1449

ret = fflush(stdout);

1450

if(ret != 0){

1451

int e = errno;

1452

if(debug){

1453

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

1454

strerror(errno));

1455

}

1456

errno = e;

1457

goto mandos_end;

1458

}

1459

1026

retval = 0;

1460

1027

}

1461

1028

}

1464

1031

1465

1032

mandos_end:

1466

1033

{

1467

if(route_added){

1468

if(not delete_local_route(ip, if_index)){

1469

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

1470

" interface %d", ip, if_index);

1471

}

1472

}

1473

1034

int e = errno;

1474

1035

free(decrypted_buffer);

1475

1036

free(buffer);

1476

1037

if(tcp_sd >= 0){

1477

ret = close(tcp_sd);

1038

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

1478

1039

}

1479

1040

if(ret == -1){

1480

1041

if(e == 0){

1635

1196

__attribute__((nonnull, warn_unused_result))

1636

1197

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

1637

1198

int ret;

1638

int old_errno;

1199

error_t ret_errno;

1639

1200

1640

1201

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

1641

1202

if(s < 0){

1642

old_errno = errno;

1203

ret_errno = errno;

1643

1204

perror_plus("socket");

1644

errno = old_errno;

1205

errno = ret_errno;

1645

1206

return false;

1646

1207

}

1647

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

1648

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

1208

strcpy(ifr->ifr_name, ifname);

1649

1209

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1650

1210

if(ret == -1){

1651

1211

if(debug){

1652

old_errno = errno;

1212

ret_errno = errno;

1653

1213

perror_plus("ioctl SIOCGIFFLAGS");

1654

errno = old_errno;

1214

errno = ret_errno;

1655

1215

}

1656

1216

return false;

1657

1217

}

1902

1462

}

1903

1463

}

1904

1464

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

1905

1517

__attribute__((nonnull))

1906

1518

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

1907

1519

const float delay){

1908

1520

struct dirent **direntries = NULL;

1909

1521

if(hookdir_fd == -1){

1910

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1911

| O_CLOEXEC);

1522

hookdir_fd = open(hookdir, O_RDONLY);

1912

1523

if(hookdir_fd == -1){

1913

1524

if(errno == ENOENT){

1914

1525

if(debug){

1921

1532

return;

1922

1533

}

1923

1534

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

1924

1537

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

1925

1538

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__ */

1926

1547

if(numhooks == -1){

1927

1548

perror_plus("scandir");

1928

1549

return;

1929

1550

}

1930

1551

struct dirent *direntry;

1931

1552

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1553

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

1937

1554

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

1938

1555

direntry = direntries[i];

1939

1556

if(debug){

1963

1580

perror_plus("setgroups");

1964

1581

_exit(EX_NOPERM);

1965

1582

}

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

}

1966

1598

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

1967

1599

if(ret == -1){

1968

1600

perror_plus("setenv");

2003

1635

_exit(EX_OSERR);

2004

1636

}

2005

1637

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

1638

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

2009

1639

if(hook_fd == -1){

2010

1640

perror_plus("openat");

2011

1641

_exit(EXIT_FAILURE);

2012

1642

}

2013

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

1643

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

2014

1644

perror_plus("close");

2015

1645

_exit(EXIT_FAILURE);

2016

1646

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

ret = close(devnull);

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

1647

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

2033

1648

environ) == -1){

2034

1649

perror_plus("fexecve");

2035

1650

_exit(EXIT_FAILURE);

2036

1651

}

2037

1652

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

1653

int status;

2044

1654

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

2045

1655

perror_plus("waitpid");

2074

1684

free(direntry);

2075

1685

}

2076

1686

free(direntries);

2077

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

1687

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

2078

1688

perror_plus("close");

2079

1689

} else {

2080

1690

hookdir_fd = -1;

2083

1693

}

2084

1694

2085

1695

__attribute__((nonnull, warn_unused_result))

2086

int bring_up_interface(const char *const interface,

2087

const float delay){

2088

int old_errno = errno;

1696

error_t bring_up_interface(const char *const interface,

1697

const float delay){

1698

error_t old_errno = errno;

2089

1699

int ret;

2090

1700

struct ifreq network;

2091

1701

unsigned int if_index = if_nametoindex(interface);

2101

1711

}

2102

1712

2103

1713

if(not interface_is_up(interface)){

2104

int ret_errno = 0;

2105

int ioctl_errno = 0;

1714

error_t ret_errno = 0, ioctl_errno = 0;

2106

1715

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

2107

1716

ret_errno = errno;

2108

1717

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

2121

1730

}

2122

1731

2123

1732

if(quit_now){

2124

ret = close(sd);

1733

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

2125

1734

if(ret == -1){

2126

1735

perror_plus("close");

2127

1736

}

2177

1786

}

2178

1787

2179

1788

/* Close the socket */

2180

ret = close(sd);

1789

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

2181

1790

if(ret == -1){

2182

1791

perror_plus("close");

2183

1792

}

2211

1820

}

2212

1821

2213

1822

__attribute__((nonnull, warn_unused_result))

2214

int take_down_interface(const char *const interface){

2215

int old_errno = errno;

1823

error_t take_down_interface(const char *const interface){

1824

error_t old_errno = errno;

2216

1825

struct ifreq network;

2217

1826

unsigned int if_index = if_nametoindex(interface);

2218

1827

if(if_index == 0){

2221

1830

return ENXIO;

2222

1831

}

2223

1832

if(interface_is_up(interface)){

2224

int ret_errno = 0;

2225

int ioctl_errno = 0;

1833

error_t ret_errno = 0, ioctl_errno = 0;

2226

1834

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

2227

1835

ret_errno = errno;

2228

1836

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

2266

1874

}

2267

1875

2268

1876

/* Close the socket */

2269

int ret = close(sd);

1877

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

2270

1878

if(ret == -1){

2271

1879

perror_plus("close");

2272

1880

}

2287

1895

}

2288

1896

2289

1897

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

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 };

2295

1902

AvahiSServiceBrowser *sb = NULL;

2296

1903

error_t ret_errno;

2297

1904

int ret;

2306

1913

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1914

const char *seckey = PATHDIR "/" SECKEY;

2308

1915

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

1916

char *interfaces_hooks = NULL;

2311

1917

2312

1918

bool gnutls_initialized = false;

2365

1971

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

2366

1972

" Diffie-Hellman key exchange",

2367

1973

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

2373

1974

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

2374

1975

.arg = "STRING",

2375

1976

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

2430

2031

}

2431

2032

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

2432

2033

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

2034

case 130: /* --priority */

2437

2035

mc.priority = arg;

2438

2036

break;

2478

2076

.args_doc = "",

2479

2077

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

2480

2078

" passwords from a Mandos server" };

2481

ret_errno = argp_parse(&argp, argc, argv,

2482

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2483

switch(ret_errno){

2079

ret = argp_parse(&argp, argc, argv,

2080

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2081

switch(ret){

2484

2082

case 0:

2485

2083

break;

2486

2084

case ENOMEM:

2487

2085

default:

2488

errno = ret_errno;

2086

errno = ret;

2489

2087

perror_plus("argp_parse");

2490

2088

exitcode = EX_OSERR;

2491

2089

goto end;

2494

2092

goto end;

2495

2093

}

2496

2094

}

2497

2095

2498

2096

{

2499

2097

/* Work around Debian bug #633582:

2500

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

2098

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

2501

2099

2502

2100

/* Re-raise privileges */

2503

ret = raise_privileges();

2504

if(ret != 0){

2505

errno = ret;

2101

ret_errno = raise_privileges();

2102

if(ret_errno != 0){

2103

errno = ret_errno;

2506

2104

perror_plus("Failed to raise privileges");

2507

2105

} else {

2508

2106

struct stat st;

2524

2122

}

2525

2123

}

2526

2124

}

2527

close(seckey_fd);

2125

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

2126

}

2529

2127

}

2530

2128

2531

2129

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

2532

2130

int pubkey_fd = open(pubkey, O_RDONLY);

2533

2131

if(pubkey_fd == -1){

2545

2143

}

2546

2144

}

2547

2145

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2146

TEMP_FAILURE_RETRY(close(pubkey_fd));

2147

}

2148

}

2149

2574

2150

/* Lower privileges */

2575

ret = lower_privileges();

2576

if(ret != 0){

2577

errno = ret;

2151

ret_errno = lower_privileges();

2152

if(ret_errno != 0){

2153

errno = ret_errno;

2578

2154

perror_plus("Failed to lower privileges");

2579

2155

}

2580

2156

}

2750

2326

errno = bring_up_interface(interface, delay);

2751

2327

if(not interface_was_up){

2752

2328

if(errno != 0){

2753

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

2754

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

2329

perror_plus("Failed to bring up interface");

2755

2330

} else {

2756

2331

errno = argz_add(&interfaces_to_take_down,

2757

2332

&interfaces_to_take_down_size,

2780

2355

goto end;

2781

2356

}

2782

2357

2783

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

2358

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

2784

2359

if(ret == -1){

2785

2360

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

2786

2361

exitcode = EX_UNAVAILABLE;

2908

2483

2909

2484

/* Allocate a new server */

2910

2485

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret);

2486

&config, NULL, NULL, &ret_errno);

2912

2487

2913

2488

/* Free the Avahi configuration data */

2914

2489

avahi_server_config_free(&config);

2917

2492

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

2918

2493

if(mc.server == NULL){

2919

2494

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

2920

avahi_strerror(ret));

2495

avahi_strerror(ret_errno));

2921

2496

exitcode = EX_UNAVAILABLE;

2922

2497

goto end;

2923

2498

}

2958

2533

end:

2959

2534

2960

2535

if(debug){

2961

if(signal_received){

2962

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

2963

argv[0], signal_received,

2964

strsignal(signal_received));

2965

} else {

2966

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

2967

}

2536

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

2968

2537

}

2969

2538

2970

2539

/* Cleanup things */

2981

2550

2982

2551

if(gnutls_initialized){

2983

2552

gnutls_certificate_free_credentials(mc.cred);

2553

gnutls_global_deinit();

2984

2554

gnutls_dh_params_deinit(mc.dh_params);

2985

2555

}

2986

2556

3009

2579

3010

2580

/* Re-raise privileges */

3011

2581

{

3012

ret = raise_privileges();

3013

if(ret != 0){

3014

errno = ret;

2582

ret_errno = raise_privileges();

2583

if(ret_errno != 0){

2584

errno = ret_errno;

3015

2585

perror_plus("Failed to raise privileges");

3016

2586

} else {

3017

2587

3025

2595

while((interface=argz_next(interfaces_to_take_down,

3026

2596

interfaces_to_take_down_size,

3027

2597

interface))){

3028

ret = take_down_interface(interface);

3029

if(ret != 0){

3030

errno = ret;

2598

ret_errno = take_down_interface(interface);

2599

if(ret_errno != 0){

2600

errno = ret_errno;

3031

2601

perror_plus("Failed to take down interface");

3032

2602

}

3033

2603

}

3038

2608

}

3039

2609

}

3040

2610

3041

ret = lower_privileges_permanently();

3042

if(ret != 0){

3043

errno = ret;

2611

ret_errno = lower_privileges_permanently();

2612

if(ret_errno != 0){

2613

errno = ret_errno;

3044

2614

perror_plus("Failed to lower privileges permanently");

3045

2615

}

3046

2616

}

3048

2618

free(interfaces_to_take_down);

3049

2619

free(interfaces_hooks);

3050

2620

3051

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

3052

uintmax_t level){

3053

struct dirent **direntries = NULL;

3054

int dret;

3055

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

3056

O_RDONLY

3057

| O_NOFOLLOW

3058

| O_DIRECTORY

3059

| O_PATH));

3060

if(dir_fd == -1){

3061

perror_plus("open");

3062

}

3063

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

3064

notdotentries, alphasort);

3065

if(numentries >= 0){

3066

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

3067

if(debug){

3068

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

3069

dirname, direntries[i]->d_name);

3070

}

3071

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

3072

if(dret == -1){

3073

if(errno == EISDIR){

3074

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

3075

AT_REMOVEDIR);

3076

}

3077

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

3078

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

3079

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

3080

/* Recurse only in this special case */

3081

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

3082

dret = 0;

3083

}

3084

if(dret == -1){

3085

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

3086

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

3087

}

3088

}

3089

free(direntries[i]);

3090

}

3091

3092

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

3093

free(direntries);

3094

if(numentries == -1){

3095

perror_plus("scandirat");

3096

}

3097

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3098

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

3099

perror_plus("rmdir");

3100

}

3101

} else {

3102

perror_plus("scandirat");

3103

}

3104

close(dir_fd);

3105

}

3106

3107

2621

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

3108

2622

if(tempdir != NULL){

3109

clean_dir_at(-1, tempdir, 0);

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

2664

}

3111

2665

3112

2666

if(quit_now){