/mandos/release : revision 237.7.243

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(), strcpy() */

49

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

50

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

51

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

52

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

53

sockaddr_in6, PF_INET6,

234

.af = af };

235

if(new_server->ip == NULL){

236

perror_plus("strdup");

237

free(new_server);

238

237

return false;

239

238

}

240

239

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

241

240

if(ret == -1){

242

241

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

242

return false;

253

243

}

254

244

/* Special case of first server */

305

295

return false;

306

296

}

307

297

308

ret = close(fd);

298

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

309

299

if(ret == -1){

310

300

perror_plus("close");

311

301

}

493

483

return plaintext_length;

494

484

}

495

485

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

486

__attribute__((warn_unused_result))

504

487

static const char *safer_gnutls_strerror(int value){

505

488

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

489

if(ret == NULL)

490

ret = "(unknown)";

491

return ret;

507

492

}

508

493

509

494

/* GnuTLS log function callback */

516

501

__attribute__((nonnull, warn_unused_result))

517

502

static int init_gnutls_global(const char *pubkeyfilename,

518

503

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

504

mandos_context *mc){

521

505

int ret;

522

unsigned int uret;

523

506

524

507

if(debug){

525

508

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

576

559

safer_gnutls_strerror(ret));

577

560

goto globalfail;

578

561

}

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

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

751

569

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

752

570

753

571

return 0;

813

631

/* ignore client certificate if any. */

814

632

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

633

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

635

816

636

return 0;

817

637

}

818

638

820

640

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

821

641

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

822

642

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

ret = close(devnull);

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

1041

643

/* Called when a Mandos server is found */

1042

644

__attribute__((nonnull, warn_unused_result))

1043

645

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

1054

656

int retval = -1;

1055

657

gnutls_session_t session;

1056

658

int pf; /* Protocol family */

1057

bool route_added = false;

1058

659

1059

660

errno = 0;

1060

661

1118

719

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

1119

720

}

1120

721

1121

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

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

723

if(tcp_sd < 0){

1123

724

int e = errno;

1124

725

perror_plus("socket");

1131

732

goto mandos_end;

1132

733

}

1133

734

735

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

1134

736

if(af == AF_INET6){

1135

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

1136

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

1137

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

737

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

738

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

1138

739

} else { /* IPv4 */

1139

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

1140

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

1141

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

740

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

741

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

1142

742

}

1143

743

if(ret < 0 ){

1144

744

int e = errno;

1214

814

goto mandos_end;

1215

815

}

1216

816

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

if(errno == ENETUNREACH

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

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;

1272

836

}

1273

837

1274

838

const char *out = mandos_protocol_version;

1457

1021

1458

1022

mandos_end:

1459

1023

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

1466

1024

int e = errno;

1467

1025

free(decrypted_buffer);

1468

1026

free(buffer);

1469

1027

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

1028

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

1471

1029

}

1472

1030

if(ret == -1){

1473

1031

if(e == 0){

1508

1066

timed out */

1509

1067

1510

1068

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1512

1069

return;

1513

1070

}

1514

1071

1894

1451

}

1895

1452

}

1896

1453

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

#ifndef O_CLOEXEC

1511

/*

1512

* Based on the example in the GNU LibC manual chapter 13.13 "File

1513

* Descriptor Flags".

1514

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

1515

*/

1516

__attribute__((warn_unused_result))

1517

static int set_cloexec_flag(int fd){

1518

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

1519

/* If reading the flags failed, return error indication now. */

1520

if(ret < 0){

1521

return ret;

1522

}

1523

/* Store modified flag word in the descriptor. */

1524

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

1525

ret | FD_CLOEXEC));

1526

}

1527

#endif /* not O_CLOEXEC */

1528

1897

1529

__attribute__((nonnull))

1898

1530

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

1899

1531

const float delay){

1900

struct dirent **direntries = NULL;

1532

struct dirent **direntries;

1901

1533

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1534

hookdir_fd = open(hookdir, O_RDONLY |

1535

#ifdef O_CLOEXEC

1536

O_CLOEXEC

1537

#else /* not O_CLOEXEC */

1538

0

1539

#endif /* not O_CLOEXEC */

1540

);

1904

1541

if(hookdir_fd == -1){

1905

1542

if(errno == ENOENT){

1906

1543

if(debug){

1912

1549

}

1913

1550

return;

1914

1551

}

1552

#ifndef O_CLOEXEC

1553

if(set_cloexec_flag(hookdir_fd) < 0){

1554

perror_plus("set_cloexec_flag");

1555

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

1556

perror_plus("close");

1557

} else {

1558

hookdir_fd = -1;

1559

}

1560

return;

1561

}

1562

#endif /* not O_CLOEXEC */

1915

1563

}

1916

1564

#ifdef __GLIBC__

1917

1565

#if __GLIBC_PREREQ(2, 15)

1931

1579

}

1932

1580

struct dirent *direntry;

1933

1581

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1582

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

1939

1583

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

1940

1584

direntry = direntries[i];

1941

1585

if(debug){

1946

1590

if(hook_pid == 0){

1947

1591

/* Child */

1948

1592

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1593

if(raise_privileges_permanently() != 0){

1951

1594

perror_plus("Failed to raise privileges");

1952

1595

_exit(EX_NOPERM);

1953

1596

}

1965

1608

perror_plus("setgroups");

1966

1609

_exit(EX_NOPERM);

1967

1610

}

1611

ret = dup2(devnull, STDIN_FILENO);

1612

if(ret == -1){

1613

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

1614

_exit(EX_OSERR);

1615

}

1616

ret = close(devnull);

1617

if(ret == -1){

1618

perror_plus("close");

1619

_exit(EX_OSERR);

1620

}

1621

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1622

if(ret == -1){

1623

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

1624

_exit(EX_OSERR);

1625

}

1968

1626

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

1969

1627

if(ret == -1){

1970

1628

perror_plus("setenv");

2005

1663

_exit(EX_OSERR);

2006

1664

}

2007

1665

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

1666

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

1667

{ direntry->d_name, NULL }, environ) == -1){

2036

1668

perror_plus("fexecve");

2037

1669

_exit(EXIT_FAILURE);

2038

1670

}

2039

1671

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

1672

int status;

2046

1673

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

2047

1674

perror_plus("waitpid");

2048

free(direntry);

2049

1675

continue;

2050

1676

}

2051

1677

if(WIFEXITED(status)){

2053

1679

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

2054

1680

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

2055

1681

WEXITSTATUS(status));

2056

free(direntry);

2057

1682

continue;

2058

1683

}

2059

1684

} else if(WIFSIGNALED(status)){

2060

1685

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

2061

1686

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

2062

1687

WTERMSIG(status));

2063

free(direntry);

2064

1688

continue;

2065

1689

} else {

2066

1690

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

2067

1691

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

2068

free(direntry);

2069

1692

continue;

2070

1693

}

2071

1694

}

2073

1696

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

2074

1697

direntry->d_name);

2075

1698

}

2076

free(direntry);

2077

1699

}

2078

free(direntries);

2079

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

1700

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

2080

1701

perror_plus("close");

2081

1702

} else {

2082

1703

hookdir_fd = -1;

2122

1743

}

2123

1744

2124

1745

if(quit_now){

2125

ret = close(sd);

1746

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

2126

1747

if(ret == -1){

2127

1748

perror_plus("close");

2128

1749

}

2138

1759

/* Raise privileges */

2139

1760

ret_errno = raise_privileges();

2140

1761

if(ret_errno != 0){

2141

errno = ret_errno;

2142

1762

perror_plus("Failed to raise privileges");

2143

1763

}

2144

1764

2178

1798

}

2179

1799

2180

1800

/* Close the socket */

2181

ret = close(sd);

1801

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

2182

1802

if(ret == -1){

2183

1803

perror_plus("close");

2184

1804

}

2248

1868

/* Raise privileges */

2249

1869

ret_errno = raise_privileges();

2250

1870

if(ret_errno != 0){

2251

errno = ret_errno;

2252

1871

perror_plus("Failed to raise privileges");

2253

1872

}

2254

1873

2266

1885

}

2267

1886

2268

1887

/* Close the socket */

2269

int ret = close(sd);

1888

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

2270

1889

if(ret == -1){

2271

1890

perror_plus("close");

2272

1891

}

2287

1906

}

2288

1907

2289

1908

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 };

1909

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

1910

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

1911

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

1912

.interfaces = NULL, .interfaces_size = 0 };

2295

1913

AvahiSServiceBrowser *sb = NULL;

2296

1914

error_t ret_errno;

2297

1915

int ret;

2306

1924

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1925

const char *seckey = PATHDIR "/" SECKEY;

2308

1926

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

1927

char *interfaces_hooks = NULL;

2311

1928

2312

1929

bool gnutls_initialized = false;

2365

1982

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

2366

1983

" Diffie-Hellman key exchange",

2367

1984

.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

1985

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

2374

1986

.arg = "STRING",

2375

1987

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

2430

2042

}

2431

2043

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

2432

2044

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

2045

case 130: /* --priority */

2437

2046

mc.priority = arg;

2438

2047

break;

2494

2103

goto end;

2495

2104

}

2496

2105

}

2497

2106

2498

2107

{

2499

2108

/* Work around Debian bug #633582:

2500

2109

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

2524

2133

}

2525

2134

}

2526

2135

}

2527

close(seckey_fd);

2136

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

2137

}

2529

2138

}

2530

2139

2531

2140

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

2532

2141

int pubkey_fd = open(pubkey, O_RDONLY);

2533

2142

if(pubkey_fd == -1){

2545

2154

}

2546

2155

}

2547

2156

}

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

2157

TEMP_FAILURE_RETRY(close(pubkey_fd));

2158

}

2159

}

2160

2574

2161

/* Lower privileges */

2575

2162

ret_errno = lower_privileges();

2576

2163

if(ret_errno != 0){

2693

2280

2694

2281

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

2695

2282

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2283

struct dirent **direntries;

2697

2284

/* Look for any good interfaces */

2698

2285

ret = scandir(sys_class_net, &direntries, good_interface,

2699

2286

alphasort);

2705

2292

if(ret_errno != 0){

2706

2293

errno = ret_errno;

2707

2294

perror_plus("argz_add");

2708

free(direntries[i]);

2709

2295

continue;

2710

2296

}

2711

2297

if(debug){

2712

2298

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

2713

2299

direntries[i]->d_name);

2714

2300

}

2715

free(direntries[i]);

2716

2301

}

2717

2302

free(direntries);

2718

2303

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2304

free(direntries);

2722

2305

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

2723

2306

exitcode = EXIT_FAILURE;

2724

2307

goto end;

2750

2333

errno = bring_up_interface(interface, delay);

2751

2334

if(not interface_was_up){

2752

2335

if(errno != 0){

2753

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

2754

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

2336

perror_plus("Failed to bring up interface");

2755

2337

} else {

2756

2338

errno = argz_add(&interfaces_to_take_down,

2757

2339

&interfaces_to_take_down_size,

2780

2362

goto end;

2781

2363

}

2782

2364

2783

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

2365

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

2784

2366

if(ret == -1){

2785

2367

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

2786

2368

exitcode = EX_UNAVAILABLE;

2989

2571

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

2990

2572

while(mc.current_server != NULL){

2991

2573

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

3000

2574

free(mc.current_server);

3001

2575

mc.current_server = next;

3002

2576

}

3006

2580

{

3007

2581

ret_errno = raise_privileges();

3008

2582

if(ret_errno != 0){

3009

errno = ret_errno;

3010

2583

perror_plus("Failed to raise privileges");

3011

2584

} else {

3012

2585

3035

2608

3036

2609

ret_errno = lower_privileges_permanently();

3037

2610

if(ret_errno != 0){

3038

errno = ret_errno;

3039

2611

perror_plus("Failed to lower privileges permanently");

3040

2612

}

3041

2613

}

3046

2618

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

3047

2619

if(tempdir != NULL){

3048

2620

struct dirent **direntries = NULL;

3049

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

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

2621

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

3053

2622

if(tempdir_fd == -1){

3054

2623

perror_plus("open");

3055

2624

} else {

3065

2634

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

3066

2635

alphasort);

3067

2636

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

2637

if(numentries > 0){

3069

2638

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

3070

2639

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

3071

2640

if(ret == -1){

3073

2642

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

3074

2643

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

3075

2644

}

3076

free(direntries[i]);

3077

2645

}

3078

2646

3079

2647

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

3086

2654

perror_plus("rmdir");

3087

2655

}

3088

2656

}

3089

close(tempdir_fd);

2657

TEMP_FAILURE_RETRY(close(tempdir_fd));

3090

2658

}

3091

2659

}

3092

2660