/mandos/trunk : revision 815

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() */

51

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

52

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

53

sockaddr_in6, PF_INET6,

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

61

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

62

*/

63

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

64

strtoimax() */

65

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

65

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

66

EAI_SYSTEM, ENETUNREACH,

67

EHOSTUNREACH, ECONNREFUSED, EPROTO,

68

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

66

70

program_invocation_short_name */

67

71

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

68

72

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

234

238

.af = af };

235

239

if(new_server->ip == NULL){

236

240

perror_plus("strdup");

241

free(new_server);

237

242

return false;

238

243

}

239

244

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

240

245

if(ret == -1){

241

246

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

free((char *)(new_server->ip));

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

242

256

return false;

243

257

}

244

258

/* Special case of first server */

295

309

return false;

296

310

}

297

311

298

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

312

ret = close(fd);

299

313

if(ret == -1){

300

314

perror_plus("close");

301

315

}

483

497

return plaintext_length;

484

498

}

485

499

500

__attribute__((warn_unused_result, const))

501

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

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

486

507

__attribute__((warn_unused_result))

487

508

static const char *safer_gnutls_strerror(int value){

488

509

const char *ret = gnutls_strerror(value);

489

if(ret == NULL)

490

ret = "(unknown)";

491

return ret;

510

return safe_string(ret);

492

511

}

493

512

494

513

/* GnuTLS log function callback */

498

517

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

499

518

}

500

519

501

__attribute__((nonnull, warn_unused_result))

520

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

502

521

static int init_gnutls_global(const char *pubkeyfilename,

503

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

504

524

mandos_context *mc){

505

525

int ret;

526

unsigned int uret;

506

527

507

528

if(debug){

508

529

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

509

530

}

510

531

511

ret = gnutls_global_init();

512

if(ret != GNUTLS_E_SUCCESS){

513

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

514

safer_gnutls_strerror(ret));

515

return -1;

516

}

517

518

532

if(debug){

519

533

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

520

534

* - GnuTLS manual

528

542

if(ret != GNUTLS_E_SUCCESS){

529

543

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

530

544

safer_gnutls_strerror(ret));

531

gnutls_global_deinit();

532

545

return -1;

533

546

}

534

547

559

572

safer_gnutls_strerror(ret));

560

573

goto globalfail;

561

574

}

562

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

563

if(ret != GNUTLS_E_SUCCESS){

564

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

565

safer_gnutls_strerror(ret));

566

goto globalfail;

567

}

568

575

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

576

if(dhparamsfilename != NULL){

577

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

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

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

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

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

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

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

624

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

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

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

633

/* Try to read the private key file */

634

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

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

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

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

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

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

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

685

if(ret != GNUTLS_E_SUCCESS){

686

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

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

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

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

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

722

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

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

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

729

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

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

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

737

mc->dh_bits);

738

}

739

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

740

if(ret != GNUTLS_E_SUCCESS){

741

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

742

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

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

569

747

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

570

748

571

749

return 0;

573

751

globalfail:

574

752

575

753

gnutls_certificate_free_credentials(mc->cred);

576

gnutls_global_deinit();

577

754

gnutls_dh_params_deinit(mc->dh_params);

578

755

return -1;

579

756

}

631

808

/* ignore client certificate if any. */

632

809

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

633

810

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

635

636

811

return 0;

637

812

}

638

813

640

815

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

641

816

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

642

817

818

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

819

__attribute__((warn_unused_result))

820

error_t raise_privileges(void){

821

error_t old_errno = errno;

822

error_t ret_errno = 0;

823

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

824

ret_errno = errno;

825

}

826

errno = old_errno;

827

return ret_errno;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

error_t raise_privileges_permanently(void){

833

error_t old_errno = errno;

834

error_t ret_errno = raise_privileges();

835

if(ret_errno != 0){

836

errno = old_errno;

837

return ret_errno;

838

}

839

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

840

ret_errno = errno;

841

}

842

errno = old_errno;

843

return ret_errno;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

error_t lower_privileges(void){

849

error_t old_errno = errno;

850

error_t ret_errno = 0;

851

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

852

ret_errno = errno;

853

}

854

errno = old_errno;

855

return ret_errno;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

error_t lower_privileges_permanently(void){

861

error_t old_errno = errno;

862

error_t ret_errno = 0;

863

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

864

ret_errno = errno;

865

}

866

errno = old_errno;

867

return ret_errno;

868

}

869

870

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

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

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

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

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

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

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

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

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

896

if(devnull == -1){

897

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

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

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

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

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

937

_exit(EX_OSERR);

938

}

939

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

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

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

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

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

961

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

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

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

980

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

981

int errno_raising = 0;

982

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

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

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

988

perror_plus("kill");

989

}

990

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

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

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

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

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

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

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

1012

return false;

1013

}

1014

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

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

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

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

643

1036

/* Called when a Mandos server is found */

644

1037

__attribute__((nonnull, warn_unused_result))

645

1038

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

656

1049

int retval = -1;

657

1050

gnutls_session_t session;

658

1051

int pf; /* Protocol family */

1052

bool route_added = false;

659

1053

660

1054

errno = 0;

661

1055

719

1113

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

720

1114

}

721

1115

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

1116

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

723

1117

if(tcp_sd < 0){

724

1118

int e = errno;

725

1119

perror_plus("socket");

732

1126

goto mandos_end;

733

1127

}

734

1128

735

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

736

1129

if(af == AF_INET6){

737

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

738

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

1130

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

1131

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

1132

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

739

1133

} else { /* IPv4 */

740

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

741

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

1134

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

1135

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

1136

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

742

1137

}

743

1138

if(ret < 0 ){

744

1139

int e = errno;

814

1209

goto mandos_end;

815

1210

}

816

1211

817

if(af == AF_INET6){

818

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

819

sizeof(struct sockaddr_in6));

820

} else {

821

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

822

sizeof(struct sockaddr_in));

823

}

824

if(ret < 0){

825

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

826

int e = errno;

827

perror_plus("connect");

828

errno = e;

829

}

830

goto mandos_end;

831

}

832

833

if(quit_now){

834

errno = EINTR;

835

goto mandos_end;

1212

while(true){

1213

if(af == AF_INET6){

1214

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

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

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

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

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

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

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

1231

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

1232

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

1233

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

1234

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

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

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

1238

1239

Avahi bug reference:

1240

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

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

836

1267

}

837

1268

838

1269

const char *out = mandos_protocol_version;

1021

1452

1022

1453

mandos_end:

1023

1454

{

1455

if(route_added){

1456

if(not delete_local_route(ip, if_index)){

1457

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

1458

" interface %d", ip, if_index);

1459

}

1460

}

1024

1461

int e = errno;

1025

1462

free(decrypted_buffer);

1026

1463

free(buffer);

1027

1464

if(tcp_sd >= 0){

1028

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

1465

ret = close(tcp_sd);

1029

1466

}

1030

1467

if(ret == -1){

1031

1468

if(e == 0){

1066

1503

timed out */

1067

1504

1068

1505

if(quit_now){

1506

avahi_s_service_resolver_free(r);

1069

1507

return;

1070

1508

}

1071

1509

1194

1632

errno = ret_errno;

1195

1633

return false;

1196

1634

}

1197

strcpy(ifr->ifr_name, ifname);

1635

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

1636

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

1198

1637

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1199

1638

if(ret == -1){

1200

1639

if(debug){

1451

1890

}

1452

1891

}

1453

1892

1454

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

1455

__attribute__((warn_unused_result))

1456

error_t raise_privileges(void){

1457

error_t old_errno = errno;

1458

error_t ret_errno = 0;

1459

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

1460

ret_errno = errno;

1461

perror_plus("seteuid");

1462

}

1463

errno = old_errno;

1464

return ret_errno;

1465

}

1466

1467

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

1468

__attribute__((warn_unused_result))

1469

error_t raise_privileges_permanently(void){

1470

error_t old_errno = errno;

1471

error_t ret_errno = raise_privileges();

1472

if(ret_errno != 0){

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

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

1477

ret_errno = errno;

1478

perror_plus("seteuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1485

__attribute__((warn_unused_result))

1486

error_t lower_privileges(void){

1487

error_t old_errno = errno;

1488

error_t ret_errno = 0;

1489

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

1490

ret_errno = errno;

1491

perror_plus("seteuid");

1492

}

1493

errno = old_errno;

1494

return ret_errno;

1495

}

1496

1497

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1499

error_t lower_privileges_permanently(void){

1500

error_t old_errno = errno;

1501

error_t ret_errno = 0;

1502

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

1503

ret_errno = errno;

1504

perror_plus("setuid");

1505

}

1506

errno = old_errno;

1507

return ret_errno;

1508

}

1509

1510

1893

__attribute__((nonnull))

1511

1894

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

1512

1895

const float delay){

1513

struct dirent **direntries;

1896

struct dirent **direntries = NULL;

1514

1897

if(hookdir_fd == -1){

1515

hookdir_fd = open(hookdir, O_RDONLY);

1898

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1899

| O_CLOEXEC);

1516

1900

if(hookdir_fd == -1){

1517

1901

if(errno == ENOENT){

1518

1902

if(debug){

1525

1909

return;

1526

1910

}

1527

1911

}

1528

#ifdef __GLIBC__

1529

#if __GLIBC_PREREQ(2, 15)

1530

1912

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

1531

1913

runnable_hook, alphasort);

1532

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

1533

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

1534

alphasort);

1535

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

1536

#else /* not __GLIBC__ */

1537

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

1538

alphasort);

1539

#endif /* not __GLIBC__ */

1540

1914

if(numhooks == -1){

1541

1915

perror_plus("scandir");

1542

1916

return;

1543

1917

}

1544

1918

struct dirent *direntry;

1545

1919

int ret;

1546

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

1920

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

1921

if(devnull == -1){

1922

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

1923

return;

1924

}

1547

1925

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

1548

1926

direntry = direntries[i];

1549

1927

if(debug){

1554

1932

if(hook_pid == 0){

1555

1933

/* Child */

1556

1934

/* Raise privileges */

1557

if(raise_privileges_permanently() != 0){

1935

errno = raise_privileges_permanently();

1936

if(errno != 0){

1558

1937

perror_plus("Failed to raise privileges");

1559

1938

_exit(EX_NOPERM);

1560

1939

}

1572

1951

perror_plus("setgroups");

1573

1952

_exit(EX_NOPERM);

1574

1953

}

1575

ret = dup2(devnull, STDIN_FILENO);

1576

if(ret == -1){

1577

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

1578

_exit(EX_OSERR);

1579

}

1580

ret = close(devnull);

1581

if(ret == -1){

1582

perror_plus("close");

1583

_exit(EX_OSERR);

1584

}

1585

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1586

if(ret == -1){

1587

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

1588

_exit(EX_OSERR);

1589

}

1590

1954

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

1591

1955

if(ret == -1){

1592

1956

perror_plus("setenv");

1627

1991

_exit(EX_OSERR);

1628

1992

}

1629

1993

}

1630

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

1994

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

1995

direntry->d_name,

1996

O_RDONLY));

1631

1997

if(hook_fd == -1){

1632

1998

perror_plus("openat");

1633

1999

_exit(EXIT_FAILURE);

1634

2000

}

1635

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

2001

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

1636

2002

perror_plus("close");

1637

2003

_exit(EXIT_FAILURE);

1638

2004

}

2005

ret = dup2(devnull, STDIN_FILENO);

2006

if(ret == -1){

2007

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

2008

_exit(EX_OSERR);

2009

}

2010

ret = close(devnull);

2011

if(ret == -1){

2012

perror_plus("close");

2013

_exit(EX_OSERR);

2014

}

2015

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2016

if(ret == -1){

2017

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

2018

_exit(EX_OSERR);

2019

}

1639

2020

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

1640

2021

environ) == -1){

1641

2022

perror_plus("fexecve");

1642

2023

_exit(EXIT_FAILURE);

1643

2024

}

1644

2025

} else {

2026

if(hook_pid == -1){

2027

perror_plus("fork");

2028

free(direntry);

2029

continue;

2030

}

1645

2031

int status;

1646

2032

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

1647

2033

perror_plus("waitpid");

2034

free(direntry);

1648

2035

continue;

1649

2036

}

1650

2037

if(WIFEXITED(status)){

1652

2039

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1653

2040

" with status %d\n", direntry->d_name,

1654

2041

WEXITSTATUS(status));

2042

free(direntry);

1655

2043

continue;

1656

2044

}

1657

2045

} else if(WIFSIGNALED(status)){

1658

2046

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1659

2047

" signal %d\n", direntry->d_name,

1660

2048

WTERMSIG(status));

2049

free(direntry);

1661

2050

continue;

1662

2051

} else {

1663

2052

fprintf_plus(stderr, "Warning: network hook \"%s\""

1664

2053

" crashed\n", direntry->d_name);

2054

free(direntry);

1665

2055

continue;

1666

2056

}

1667

2057

}

1669

2059

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1670

2060

direntry->d_name);

1671

2061

}

2062

free(direntry);

1672

2063

}

1673

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

2064

free(direntries);

2065

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

1674

2066

perror_plus("close");

1675

2067

} else {

1676

2068

hookdir_fd = -1;

1716

2108

}

1717

2109

1718

2110

if(quit_now){

1719

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

2111

ret = close(sd);

1720

2112

if(ret == -1){

1721

2113

perror_plus("close");

1722

2114

}

1732

2124

/* Raise privileges */

1733

2125

ret_errno = raise_privileges();

1734

2126

if(ret_errno != 0){

2127

errno = ret_errno;

1735

2128

perror_plus("Failed to raise privileges");

1736

2129

}

1737

2130

1771

2164

}

1772

2165

1773

2166

/* Close the socket */

1774

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

2167

ret = close(sd);

1775

2168

if(ret == -1){

1776

2169

perror_plus("close");

1777

2170

}

1841

2234

/* Raise privileges */

1842

2235

ret_errno = raise_privileges();

1843

2236

if(ret_errno != 0){

2237

errno = ret_errno;

1844

2238

perror_plus("Failed to raise privileges");

1845

2239

}

1846

2240

1858

2252

}

1859

2253

1860

2254

/* Close the socket */

1861

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

2255

int ret = close(sd);

1862

2256

if(ret == -1){

1863

2257

perror_plus("close");

1864

2258

}

1879

2273

}

1880

2274

1881

2275

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

1882

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

1883

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

1884

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

1885

.interfaces = NULL, .interfaces_size = 0 };

2276

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

2277

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

2278

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

2279

.current_server = NULL, .interfaces = NULL,

2280

.interfaces_size = 0 };

1886

2281

AvahiSServiceBrowser *sb = NULL;

1887

2282

error_t ret_errno;

1888

2283

int ret;

1897

2292

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1898

2293

const char *seckey = PATHDIR "/" SECKEY;

1899

2294

const char *pubkey = PATHDIR "/" PUBKEY;

2295

const char *dh_params_file = NULL;

1900

2296

char *interfaces_hooks = NULL;

1901

2297

1902

2298

bool gnutls_initialized = false;

1955

2351

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

1956

2352

" Diffie-Hellman key exchange",

1957

2353

.group = 2 },

2354

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

2355

.arg = "FILE",

2356

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

2357

" for the Diffie-Hellman key exchange",

2358

.group = 2 },

1958

2359

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

1959

2360

.arg = "STRING",

1960

2361

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

2015

2416

}

2016

2417

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

2017

2418

break;

2419

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

2420

dh_params_file = arg;

2421

break;

2018

2422

case 130: /* --priority */

2019

2423

mc.priority = arg;

2020

2424

break;

2076

2480

goto end;

2077

2481

}

2078

2482

}

2079

2483

2080

2484

{

2081

2485

/* Work around Debian bug #633582:

2082

2486

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

2106

2510

}

2107

2511

}

2108

2512

}

2109

TEMP_FAILURE_RETRY(close(seckey_fd));

2513

close(seckey_fd);

2110

2514

}

2111

2515

}

2112

2516

2113

2517

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

2114

2518

int pubkey_fd = open(pubkey, O_RDONLY);

2115

2519

if(pubkey_fd == -1){

2127

2531

}

2128

2532

}

2129

2533

}

2130

TEMP_FAILURE_RETRY(close(pubkey_fd));

2131

}

2132

}

2133

2534

close(pubkey_fd);

2535

}

2536

}

2537

2538

if(dh_params_file != NULL

2539

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

2540

int dhparams_fd = open(dh_params_file, O_RDONLY);

2541

if(dhparams_fd == -1){

2542

perror_plus("open");

2543

} else {

2544

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

2545

if(ret == -1){

2546

perror_plus("fstat");

2547

} else {

2548

if(S_ISREG(st.st_mode)

2549

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

2550

ret = fchown(dhparams_fd, uid, gid);

2551

if(ret == -1){

2552

perror_plus("fchown");

2553

}

2554

}

2555

}

2556

close(dhparams_fd);

2557

}

2558

}

2559

2134

2560

/* Lower privileges */

2135

2561

ret_errno = lower_privileges();

2136

2562

if(ret_errno != 0){

2253

2679

2254

2680

/* If no interfaces were specified, make a list */

2255

2681

if(mc.interfaces == NULL){

2256

struct dirent **direntries;

2682

struct dirent **direntries = NULL;

2257

2683

/* Look for any good interfaces */

2258

2684

ret = scandir(sys_class_net, &direntries, good_interface,

2259

2685

alphasort);

2265

2691

if(ret_errno != 0){

2266

2692

errno = ret_errno;

2267

2693

perror_plus("argz_add");

2694

free(direntries[i]);

2268

2695

continue;

2269

2696

}

2270

2697

if(debug){

2271

2698

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2272

2699

direntries[i]->d_name);

2273

2700

}

2701

free(direntries[i]);

2274

2702

}

2275

2703

free(direntries);

2276

2704

} else {

2277

free(direntries);

2705

if(ret == 0){

2706

free(direntries);

2707

}

2278

2708

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

2279

2709

exitcode = EXIT_FAILURE;

2280

2710

goto end;

2306

2736

errno = bring_up_interface(interface, delay);

2307

2737

if(not interface_was_up){

2308

2738

if(errno != 0){

2309

perror_plus("Failed to bring up interface");

2739

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

2740

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

2310

2741

} else {

2311

2742

errno = argz_add(&interfaces_to_take_down,

2312

2743

&interfaces_to_take_down_size,

2335

2766

goto end;

2336

2767

}

2337

2768

2338

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

2769

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

2339

2770

if(ret == -1){

2340

2771

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

2341

2772

exitcode = EX_UNAVAILABLE;

2530

2961

2531

2962

if(gnutls_initialized){

2532

2963

gnutls_certificate_free_credentials(mc.cred);

2533

gnutls_global_deinit();

2534

2964

gnutls_dh_params_deinit(mc.dh_params);

2535

2965

}

2536

2966

2544

2974

mc.current_server->prev->next = NULL;

2545

2975

while(mc.current_server != NULL){

2546

2976

server *next = mc.current_server->next;

2977

#ifdef __GNUC__

2978

#pragma GCC diagnostic push

2979

#pragma GCC diagnostic ignored "-Wcast-qual"

2980

#endif

2981

free((char *)(mc.current_server->ip));

2982

#ifdef __GNUC__

2983

#pragma GCC diagnostic pop

2984

#endif

2547

2985

free(mc.current_server);

2548

2986

mc.current_server = next;

2549

2987

}

2553

2991

{

2554

2992

ret_errno = raise_privileges();

2555

2993

if(ret_errno != 0){

2994

errno = ret_errno;

2556

2995

perror_plus("Failed to raise privileges");

2557

2996

} else {

2558

2997

2581

3020

2582

3021

ret_errno = lower_privileges_permanently();

2583

3022

if(ret_errno != 0){

3023

errno = ret_errno;

2584

3024

perror_plus("Failed to lower privileges permanently");

2585

3025

}

2586

3026

}

2588

3028

free(interfaces_to_take_down);

2589

3029

free(interfaces_hooks);

2590

3030

3031

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

3032

uintmax_t level){

3033

struct dirent **direntries = NULL;

3034

int dret;

3035

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

3036

O_RDONLY

3037

| O_NOFOLLOW

3038

| O_DIRECTORY

3039

| O_PATH));

3040

if(dir_fd == -1){

3041

perror_plus("open");

3042

}

3043

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

3044

notdotentries, alphasort);

3045

if(numentries >= 0){

3046

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

3047

if(debug){

3048

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

3049

dirname, direntries[i]->d_name);

3050

}

3051

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

3052

if(dret == -1){

3053

if(errno == EISDIR){

3054

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

3055

AT_REMOVEDIR);

3056

}

3057

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

3058

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

3059

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

3060

/* Recurse only in this special case */

3061

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

3062

dret = 0;

3063

}

3064

if(dret == -1){

3065

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

3066

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

3067

}

3068

}

3069

free(direntries[i]);

3070

}

3071

3072

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

3073

free(direntries);

3074

if(numentries == -1){

3075

perror_plus("scandirat");

3076

}

3077

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3078

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

3079

perror_plus("rmdir");

3080

}

3081

} else {

3082

perror_plus("scandirat");

3083

}

3084

close(dir_fd);

3085

}

3086

2591

3087

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

2592

3088

if(tempdir != NULL){

2593

struct dirent **direntries = NULL;

2594

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

2595

O_NOFOLLOW));

2596

if(tempdir_fd == -1){

2597

perror_plus("open");

2598

} else {

2599

#ifdef __GLIBC__

2600

#if __GLIBC_PREREQ(2, 15)

2601

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

2602

notdotentries, alphasort);

2603

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

2604

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

2605

alphasort);

2606

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

2607

#else /* not __GLIBC__ */

2608

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

2609

alphasort);

2610

#endif /* not __GLIBC__ */

2611

if(numentries > 0){

2612

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

2613

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

2614

if(ret == -1){

2615

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

2616

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

2617

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

2618

}

2619

}

2620

2621

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

2622

free(direntries);

2623

if(numentries == -1){

2624

perror_plus("scandir");

2625

}

2626

ret = rmdir(tempdir);

2627

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

2628

perror_plus("rmdir");

2629

}

2630

}

2631

TEMP_FAILURE_RETRY(close(tempdir_fd));

2632

}

3089

clean_dir_at(-1, tempdir, 0);

2633

3090

}

2634

3091

2635

3092

if(quit_now){