/mandos/trunk : revision 710

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() */

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,

240

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

241

if(ret == -1){

242

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

243

free(new_server->ip);

251

244

free(new_server);

252

245

return false;

253

246

}

305

298

return false;

306

299

}

307

300

308

ret = close(fd);

301

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

309

302

if(ret == -1){

310

303

perror_plus("close");

311

304

}

493

486

return plaintext_length;

494

487

}

495

488

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

489

__attribute__((warn_unused_result))

504

490

static const char *safer_gnutls_strerror(int value){

505

491

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

492

if(ret == NULL)

493

ret = "(unknown)";

494

return ret;

507

495

}

508

496

509

497

/* GnuTLS log function callback */

513

501

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

514

502

}

515

503

516

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

504

__attribute__((nonnull, warn_unused_result))

517

505

static int init_gnutls_global(const char *pubkeyfilename,

518

506

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

507

mandos_context *mc){

521

508

int ret;

522

unsigned int uret;

523

509

524

510

if(debug){

525

511

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

526

512

}

527

513

514

ret = gnutls_global_init();

515

if(ret != GNUTLS_E_SUCCESS){

516

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

517

safer_gnutls_strerror(ret));

518

return -1;

519

}

520

528

521

if(debug){

529

522

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

530

523

* - GnuTLS manual

538

531

if(ret != GNUTLS_E_SUCCESS){

539

532

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

540

533

safer_gnutls_strerror(ret));

534

gnutls_global_deinit();

541

535

return -1;

542

536

}

543

537

568

562

safer_gnutls_strerror(ret));

569

563

goto globalfail;

570

564

}

571

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

572

if(dhparamsfilename != NULL){

573

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

574

do {

575

int dhpfile = open(dhparamsfilename, O_RDONLY);

576

if(dhpfile == -1){

577

perror_plus("open");

578

dhparamsfilename = NULL;

579

break;

580

}

581

size_t params_capacity = 0;

582

while(true){

583

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

584

(size_t)params.size,

585

(size_t)params_capacity);

586

if(params_capacity == 0){

587

perror_plus("incbuffer");

588

free(params.data);

589

params.data = NULL;

590

dhparamsfilename = NULL;

591

break;

592

}

593

ssize_t bytes_read = read(dhpfile,

594

params.data + params.size,

595

BUFFER_SIZE);

596

/* EOF */

597

if(bytes_read == 0){

598

break;

599

}

600

/* check bytes_read for failure */

601

if(bytes_read < 0){

602

perror_plus("read");

603

free(params.data);

604

params.data = NULL;

605

dhparamsfilename = NULL;

606

break;

607

}

608

params.size += (unsigned int)bytes_read;

609

}

610

if(params.data == NULL){

611

dhparamsfilename = NULL;

612

}

613

if(dhparamsfilename == NULL){

614

break;

615

}

616

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

617

GNUTLS_X509_FMT_PEM);

618

if(ret != GNUTLS_E_SUCCESS){

619

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

620

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

621

safer_gnutls_strerror(ret));

622

dhparamsfilename = NULL;

623

}

624

} while(false);

625

}

626

if(dhparamsfilename == NULL){

627

if(mc->dh_bits == 0){

628

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

629

/* Try to read the private key file */

630

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

631

do {

632

int secfile = open(seckeyfilename, O_RDONLY);

633

if(secfile == -1){

634

perror_plus("open");

635

break;

636

}

637

size_t buffer_capacity = 0;

638

while(true){

639

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

640

(size_t)buffer.size,

641

(size_t)buffer_capacity);

642

if(buffer_capacity == 0){

643

perror_plus("incbuffer");

644

free(buffer.data);

645

buffer.data = NULL;

646

break;

647

}

648

ssize_t bytes_read = read(secfile,

649

buffer.data + buffer.size,

650

BUFFER_SIZE);

651

/* EOF */

652

if(bytes_read == 0){

653

break;

654

}

655

/* check bytes_read for failure */

656

if(bytes_read < 0){

657

perror_plus("read");

658

free(buffer.data);

659

buffer.data = NULL;

660

break;

661

}

662

buffer.size += (unsigned int)bytes_read;

663

}

664

close(secfile);

665

} while(false);

666

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

667

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

668

if(buffer.data != NULL){

669

{

670

gnutls_openpgp_privkey_t privkey = NULL;

671

ret = gnutls_openpgp_privkey_init(&privkey);

672

if(ret != GNUTLS_E_SUCCESS){

673

fprintf_plus(stderr, "Error initializing OpenPGP key"

674

" structure: %s",

675

safer_gnutls_strerror(ret));

676

free(buffer.data);

677

buffer.data = NULL;

678

} else {

679

ret = gnutls_openpgp_privkey_import

680

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

681

if(ret != GNUTLS_E_SUCCESS){

682

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

683

safer_gnutls_strerror(ret));

684

privkey = NULL;

685

}

686

free(buffer.data);

687

buffer.data = NULL;

688

if(privkey != NULL){

689

/* Use private key to suggest an appropriate

690

sec_param */

691

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

692

gnutls_openpgp_privkey_deinit(privkey);

693

if(debug){

694

fprintf_plus(stderr, "This OpenPGP key implies using"

695

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

696

safe_string(gnutls_sec_param_get_name

697

(sec_param)));

698

}

699

}

700

}

701

}

702

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

703

/* Err on the side of caution */

704

sec_param = GNUTLS_SEC_PARAM_ULTRA;

705

if(debug){

706

fprintf_plus(stderr, "Falling back to security parameter"

707

" \"%s\"\n",

708

safe_string(gnutls_sec_param_get_name

709

(sec_param)));

710

}

711

}

712

}

713

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

714

if(uret != 0){

715

mc->dh_bits = uret;

716

if(debug){

717

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

718

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

719

safe_string(gnutls_sec_param_get_name

720

(sec_param)),

721

mc->dh_bits);

722

}

723

} else {

724

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

725

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

726

safe_string(gnutls_sec_param_get_name

727

(sec_param)),

728

safer_gnutls_strerror(ret));

729

goto globalfail;

730

}

731

} else if(debug){

732

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

733

mc->dh_bits);

734

}

735

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

736

if(ret != GNUTLS_E_SUCCESS){

737

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

738

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

739

safer_gnutls_strerror(ret));

740

goto globalfail;

741

}

742

}

565

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

566

if(ret != GNUTLS_E_SUCCESS){

567

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

568

safer_gnutls_strerror(ret));

569

goto globalfail;

570

}

571

743

572

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

744

573

745

574

return 0;

747

576

globalfail:

748

577

749

578

gnutls_certificate_free_credentials(mc->cred);

579

gnutls_global_deinit();

750

580

gnutls_dh_params_deinit(mc->dh_params);

751

581

return -1;

752

582

}

804

634

/* ignore client certificate if any. */

805

635

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

806

636

637

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

638

807

639

return 0;

808

640

}

809

641

811

643

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

812

644

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

813

645

814

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

815

__attribute__((warn_unused_result))

816

error_t raise_privileges(void){

817

error_t old_errno = errno;

818

error_t ret_errno = 0;

819

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

820

ret_errno = errno;

821

}

822

errno = old_errno;

823

return ret_errno;

824

}

825

826

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

827

__attribute__((warn_unused_result))

828

error_t raise_privileges_permanently(void){

829

error_t old_errno = errno;

830

error_t ret_errno = raise_privileges();

831

if(ret_errno != 0){

832

errno = old_errno;

833

return ret_errno;

834

}

835

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

836

ret_errno = errno;

837

}

838

errno = old_errno;

839

return ret_errno;

840

}

841

842

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

843

__attribute__((warn_unused_result))

844

error_t lower_privileges(void){

845

error_t old_errno = errno;

846

error_t ret_errno = 0;

847

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

848

ret_errno = errno;

849

}

850

errno = old_errno;

851

return ret_errno;

852

}

853

854

/* Lower privileges permanently */

855

__attribute__((warn_unused_result))

856

error_t lower_privileges_permanently(void){

857

error_t old_errno = errno;

858

error_t ret_errno = 0;

859

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

860

ret_errno = errno;

861

}

862

errno = old_errno;

863

return ret_errno;

864

}

865

866

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

867

__attribute__((nonnull, warn_unused_result))

868

static bool add_delete_local_route(const bool add,

869

const char *address,

870

AvahiIfIndex if_index){

871

int ret;

872

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

873

char add_arg[] = "add";

874

char delete_arg[] = "delete";

875

char debug_flag[] = "--debug";

876

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

877

if(pluginhelperdir == NULL){

878

if(debug){

879

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

880

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

881

}

882

return false;

883

}

884

885

char interface[IF_NAMESIZE];

886

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

887

perror_plus("if_indextoname");

888

return false;

889

}

890

891

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

892

if(devnull == -1){

893

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

894

return false;

895

}

896

pid_t pid = fork();

897

if(pid == 0){

898

/* Child */

899

/* Raise privileges */

900

errno = raise_privileges_permanently();

901

if(errno != 0){

902

perror_plus("Failed to raise privileges");

903

/* _exit(EX_NOPERM); */

904

} else {

905

/* Set group */

906

errno = 0;

907

ret = setgid(0);

908

if(ret == -1){

909

perror_plus("setgid");

910

_exit(EX_NOPERM);

911

}

912

/* Reset supplementary groups */

913

errno = 0;

914

ret = setgroups(0, NULL);

915

if(ret == -1){

916

perror_plus("setgroups");

917

_exit(EX_NOPERM);

918

}

919

}

920

ret = dup2(devnull, STDIN_FILENO);

921

if(ret == -1){

922

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

923

_exit(EX_OSERR);

924

}

925

ret = close(devnull);

926

if(ret == -1){

927

perror_plus("close");

928

_exit(EX_OSERR);

929

}

930

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

931

if(ret == -1){

932

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

933

_exit(EX_OSERR);

934

}

935

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

936

O_RDONLY

937

| O_DIRECTORY

938

| O_PATH

939

| O_CLOEXEC));

940

if(helperdir_fd == -1){

941

perror_plus("open");

942

_exit(EX_UNAVAILABLE);

943

}

944

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

945

helper, O_RDONLY));

946

if(helper_fd == -1){

947

perror_plus("openat");

948

close(helperdir_fd);

949

_exit(EX_UNAVAILABLE);

950

}

951

close(helperdir_fd);

952

#ifdef __GNUC__

953

#pragma GCC diagnostic push

954

#pragma GCC diagnostic ignored "-Wcast-qual"

955

#endif

956

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

957

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

958

interface, debug ? debug_flag : NULL, NULL },

959

environ) == -1){

960

#ifdef __GNUC__

961

#pragma GCC diagnostic pop

962

#endif

963

perror_plus("fexecve");

964

_exit(EXIT_FAILURE);

965

}

966

}

967

if(pid == -1){

968

perror_plus("fork");

969

return false;

970

}

971

int status;

972

pid_t pret = -1;

973

errno = 0;

974

do {

975

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

976

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

977

int errno_raising = 0;

978

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

979

errno_raising = errno;

980

perror_plus("Failed to raise privileges in order to"

981

" kill helper program");

982

}

983

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

984

perror_plus("kill");

985

}

986

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

987

perror_plus("Failed to lower privileges after killing"

988

" helper program");

989

}

990

return false;

991

}

992

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

993

if(pret == -1){

994

perror_plus("waitpid");

995

return false;

996

}

997

if(WIFEXITED(status)){

998

if(WEXITSTATUS(status) != 0){

999

fprintf_plus(stderr, "Error: iprouteadddel exited"

1000

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

1001

return false;

1002

}

1003

return true;

1004

}

1005

if(WIFSIGNALED(status)){

1006

fprintf_plus(stderr, "Error: iprouteadddel died by"

1007

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

1008

return false;

1009

}

1010

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

1011

return false;

1012

}

1013

1014

__attribute__((nonnull, warn_unused_result))

1015

static bool add_local_route(const char *address,

1016

AvahiIfIndex if_index){

1017

if(debug){

1018

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

1019

}

1020

return add_delete_local_route(true, address, if_index);

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool delete_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(false, address, if_index);

1030

}

1031

1032

646

/* Called when a Mandos server is found */

1033

647

__attribute__((nonnull, warn_unused_result))

1034

648

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

1045

659

int retval = -1;

1046

660

gnutls_session_t session;

1047

661

int pf; /* Protocol family */

1048

bool route_added = false;

1049

662

1050

663

errno = 0;

1051

664

1109

722

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

1110

723

}

1111

724

1112

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

725

tcp_sd = socket(pf, SOCK_STREAM, 0);

1113

726

if(tcp_sd < 0){

1114

727

int e = errno;

1115

728

perror_plus("socket");

1122

735

goto mandos_end;

1123

736

}

1124

737

738

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

1125

739

if(af == AF_INET6){

1126

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

1127

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

1128

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

740

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

741

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

1129

742

} else { /* IPv4 */

1130

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

1131

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

1132

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

743

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

744

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

1133

745

}

1134

746

if(ret < 0 ){

1135

747

int e = errno;

1205

817

goto mandos_end;

1206

818

}

1207

819

1208

while(true){

1209

if(af == AF_INET6){

1210

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

1211

sizeof(struct sockaddr_in6));

1212

} else {

1213

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

1214

sizeof(struct sockaddr_in));

1215

}

1216

if(ret < 0){

1217

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

1218

and if_index != AVAHI_IF_UNSPEC

1219

and connect_to == NULL

1220

and not route_added and

1221

((af == AF_INET6 and not

1222

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1223

&to)->sin6_addr)))

1224

or (af == AF_INET and

1225

/* Not a a IPv4LL address */

1226

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

1227

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

1228

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

1229

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

1230

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

1231

connect to a Mandos server announced by Avahi on a server

1232

host with a global address. Work around this by retrying

1233

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

1234

1235

Avahi bug reference:

1236

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

1237

https://bugs.debian.org/587961

1238

*/

1239

if(debug){

1240

fprintf_plus(stderr, "Mandos server unreachable, trying"

1241

" direct route\n");

1242

}

1243

int e = errno;

1244

route_added = add_local_route(ip, if_index);

1245

if(route_added){

1246

continue;

1247

}

1248

errno = e;

1249

}

1250

if(errno != ECONNREFUSED or debug){

1251

int e = errno;

1252

perror_plus("connect");

1253

errno = e;

1254

}

1255

goto mandos_end;

1256

}

1257

1258

if(quit_now){

1259

errno = EINTR;

1260

goto mandos_end;

1261

}

1262

break;

820

if(af == AF_INET6){

821

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

822

sizeof(struct sockaddr_in6));

823

} else {

824

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

825

sizeof(struct sockaddr_in));

826

}

827

if(ret < 0){

828

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

829

int e = errno;

830

perror_plus("connect");

831

errno = e;

832

}

833

goto mandos_end;

834

}

835

836

if(quit_now){

837

errno = EINTR;

838

goto mandos_end;

1263

839

}

1264

840

1265

841

const char *out = mandos_protocol_version;

1448

1024

1449

1025

mandos_end:

1450

1026

{

1451

if(route_added){

1452

if(not delete_local_route(ip, if_index)){

1453

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

1454

" interface %d", ip, if_index);

1455

}

1456

}

1457

1027

int e = errno;

1458

1028

free(decrypted_buffer);

1459

1029

free(buffer);

1460

1030

if(tcp_sd >= 0){

1461

ret = close(tcp_sd);

1031

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

1462

1032

}

1463

1033

if(ret == -1){

1464

1034

if(e == 0){

1499

1069

timed out */

1500

1070

1501

1071

if(quit_now){

1502

avahi_s_service_resolver_free(r);

1503

1072

return;

1504

1073

}

1505

1074

1628

1197

errno = ret_errno;

1629

1198

return false;

1630

1199

}

1631

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

1632

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

1200

strcpy(ifr->ifr_name, ifname);

1633

1201

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1634

1202

if(ret == -1){

1635

1203

if(debug){

1886

1454

}

1887

1455

}

1888

1456

1457

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

1458

__attribute__((warn_unused_result))

1459

error_t raise_privileges(void){

1460

error_t old_errno = errno;

1461

error_t ret_errno = 0;

1462

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

1463

ret_errno = errno;

1464

}

1465

errno = old_errno;

1466

return ret_errno;

1467

}

1468

1469

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

1470

__attribute__((warn_unused_result))

1471

error_t raise_privileges_permanently(void){

1472

error_t old_errno = errno;

1473

error_t ret_errno = raise_privileges();

1474

if(ret_errno != 0){

1475

errno = old_errno;

1476

return ret_errno;

1477

}

1478

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

1479

ret_errno = errno;

1480

}

1481

errno = old_errno;

1482

return ret_errno;

1483

}

1484

1485

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

1486

__attribute__((warn_unused_result))

1487

error_t lower_privileges(void){

1488

error_t old_errno = errno;

1489

error_t ret_errno = 0;

1490

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

1491

ret_errno = errno;

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

}

1505

errno = old_errno;

1506

return ret_errno;

1507

}

1508

1889

1509

__attribute__((nonnull))

1890

1510

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

1891

1511

const float delay){

1892

1512

struct dirent **direntries = NULL;

1893

1513

if(hookdir_fd == -1){

1894

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1895

| O_CLOEXEC);

1514

hookdir_fd = open(hookdir, O_RDONLY);

1896

1515

if(hookdir_fd == -1){

1897

1516

if(errno == ENOENT){

1898

1517

if(debug){

1905

1524

return;

1906

1525

}

1907

1526

}

1527

#ifdef __GLIBC__

1528

#if __GLIBC_PREREQ(2, 15)

1908

1529

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

1909

1530

runnable_hook, alphasort);

1531

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

1532

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

1533

alphasort);

1534

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

1535

#else /* not __GLIBC__ */

1536

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

1537

alphasort);

1538

#endif /* not __GLIBC__ */

1910

1539

if(numhooks == -1){

1911

1540

perror_plus("scandir");

1912

1541

return;

1913

1542

}

1914

1543

struct dirent *direntry;

1915

1544

int ret;

1916

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

1917

if(devnull == -1){

1918

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

1919

return;

1920

}

1545

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

1921

1546

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

1922

1547

direntry = direntries[i];

1923

1548

if(debug){

1947

1572

perror_plus("setgroups");

1948

1573

_exit(EX_NOPERM);

1949

1574

}

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

}

1950

1590

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

1951

1591

if(ret == -1){

1952

1592

perror_plus("setenv");

1987

1627

_exit(EX_OSERR);

1988

1628

}

1989

1629

}

1990

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

1991

direntry->d_name,

1992

O_RDONLY));

1630

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

1993

1631

if(hook_fd == -1){

1994

1632

perror_plus("openat");

1995

1633

_exit(EXIT_FAILURE);

1996

1634

}

1997

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

1635

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

1998

1636

perror_plus("close");

1999

1637

_exit(EXIT_FAILURE);

2000

1638

}

2001

ret = dup2(devnull, STDIN_FILENO);

2002

if(ret == -1){

2003

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

2004

_exit(EX_OSERR);

2005

}

2006

ret = close(devnull);

2007

if(ret == -1){

2008

perror_plus("close");

2009

_exit(EX_OSERR);

2010

}

2011

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2012

if(ret == -1){

2013

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

2014

_exit(EX_OSERR);

2015

}

2016

1639

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

2017

1640

environ) == -1){

2018

1641

perror_plus("fexecve");

2019

1642

_exit(EXIT_FAILURE);

2020

1643

}

2021

1644

} else {

2022

if(hook_pid == -1){

2023

perror_plus("fork");

2024

free(direntry);

2025

continue;

2026

}

2027

1645

int status;

2028

1646

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

2029

1647

perror_plus("waitpid");

2030

free(direntry);

2031

1648

continue;

2032

1649

}

2033

1650

if(WIFEXITED(status)){

2035

1652

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

2036

1653

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

2037

1654

WEXITSTATUS(status));

2038

free(direntry);

2039

1655

continue;

2040

1656

}

2041

1657

} else if(WIFSIGNALED(status)){

2042

1658

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

2043

1659

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

2044

1660

WTERMSIG(status));

2045

free(direntry);

2046

1661

continue;

2047

1662

} else {

2048

1663

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

2049

1664

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

2050

free(direntry);

2051

1665

continue;

2052

1666

}

2053

1667

}

2055

1669

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

2056

1670

direntry->d_name);

2057

1671

}

2058

free(direntry);

2059

1672

}

2060

1673

free(direntries);

2061

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

1674

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

2062

1675

perror_plus("close");

2063

1676

} else {

2064

1677

hookdir_fd = -1;

2104

1717

}

2105

1718

2106

1719

if(quit_now){

2107

ret = close(sd);

1720

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

2108

1721

if(ret == -1){

2109

1722

perror_plus("close");

2110

1723

}

2160

1773

}

2161

1774

2162

1775

/* Close the socket */

2163

ret = close(sd);

1776

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

2164

1777

if(ret == -1){

2165

1778

perror_plus("close");

2166

1779

}

2248

1861

}

2249

1862

2250

1863

/* Close the socket */

2251

int ret = close(sd);

1864

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

2252

1865

if(ret == -1){

2253

1866

perror_plus("close");

2254

1867

}

2269

1882

}

2270

1883

2271

1884

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

2272

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

2273

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

2274

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

2275

.current_server = NULL, .interfaces = NULL,

2276

.interfaces_size = 0 };

1885

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

1886

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

1887

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

1888

.interfaces = NULL, .interfaces_size = 0 };

2277

1889

AvahiSServiceBrowser *sb = NULL;

2278

1890

error_t ret_errno;

2279

1891

int ret;

2288

1900

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2289

1901

const char *seckey = PATHDIR "/" SECKEY;

2290

1902

const char *pubkey = PATHDIR "/" PUBKEY;

2291

const char *dh_params_file = NULL;

2292

1903

char *interfaces_hooks = NULL;

2293

1904

2294

1905

bool gnutls_initialized = false;

2347

1958

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

2348

1959

" Diffie-Hellman key exchange",

2349

1960

.group = 2 },

2350

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

2351

.arg = "FILE",

2352

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

2353

" for the Diffie-Hellman key exchange",

2354

.group = 2 },

2355

1961

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

2356

1962

.arg = "STRING",

2357

1963

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

2412

2018

}

2413

2019

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

2414

2020

break;

2415

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

2416

dh_params_file = arg;

2417

break;

2418

2021

case 130: /* --priority */

2419

2022

mc.priority = arg;

2420

2023

break;

2476

2079

goto end;

2477

2080

}

2478

2081

}

2479

2082

2480

2083

{

2481

2084

/* Work around Debian bug #633582:

2482

2085

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

2506

2109

}

2507

2110

}

2508

2111

}

2509

close(seckey_fd);

2112

TEMP_FAILURE_RETRY(close(seckey_fd));

2510

2113

}

2511

2114

}

2512

2115

2513

2116

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

2514

2117

int pubkey_fd = open(pubkey, O_RDONLY);

2515

2118

if(pubkey_fd == -1){

2527

2130

}

2528

2131

}

2529

2132

}

2530

close(pubkey_fd);

2531

}

2532

}

2533

2534

if(dh_params_file != NULL

2535

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

2536

int dhparams_fd = open(dh_params_file, O_RDONLY);

2537

if(dhparams_fd == -1){

2538

perror_plus("open");

2539

} else {

2540

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

2541

if(ret == -1){

2542

perror_plus("fstat");

2543

} else {

2544

if(S_ISREG(st.st_mode)

2545

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

2546

ret = fchown(dhparams_fd, uid, gid);

2547

if(ret == -1){

2548

perror_plus("fchown");

2549

}

2550

}

2551

}

2552

close(dhparams_fd);

2553

}

2554

}

2555

2133

TEMP_FAILURE_RETRY(close(pubkey_fd));

2134

}

2135

}

2136

2556

2137

/* Lower privileges */

2557

2138

ret_errno = lower_privileges();

2558

2139

if(ret_errno != 0){

2687

2268

if(ret_errno != 0){

2688

2269

errno = ret_errno;

2689

2270

perror_plus("argz_add");

2690

free(direntries[i]);

2691

2271

continue;

2692

2272

}

2693

2273

if(debug){

2694

2274

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

2695

2275

direntries[i]->d_name);

2696

2276

}

2697

free(direntries[i]);

2698

2277

}

2699

2278

free(direntries);

2700

2279

} else {

2732

2311

errno = bring_up_interface(interface, delay);

2733

2312

if(not interface_was_up){

2734

2313

if(errno != 0){

2735

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

2736

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

2314

perror_plus("Failed to bring up interface");

2737

2315

} else {

2738

2316

errno = argz_add(&interfaces_to_take_down,

2739

2317

&interfaces_to_take_down_size,

2762

2340

goto end;

2763

2341

}

2764

2342

2765

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

2343

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

2766

2344

if(ret == -1){

2767

2345

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

2768

2346

exitcode = EX_UNAVAILABLE;

2957

2535

2958

2536

if(gnutls_initialized){

2959

2537

gnutls_certificate_free_credentials(mc.cred);

2538

gnutls_global_deinit();

2960

2539

gnutls_dh_params_deinit(mc.dh_params);

2961

2540

}

2962

2541

2970

2549

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

2971

2550

while(mc.current_server != NULL){

2972

2551

server *next = mc.current_server->next;

2973

#ifdef __GNUC__

2974

#pragma GCC diagnostic push

2975

#pragma GCC diagnostic ignored "-Wcast-qual"

2976

#endif

2977

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

2978

#ifdef __GNUC__

2979

#pragma GCC diagnostic pop

2980

#endif

2981

2552

free(mc.current_server);

2982

2553

mc.current_server = next;

2983

2554

}

3027

2598

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

3028

2599

if(tempdir != NULL){

3029

2600

struct dirent **direntries = NULL;

3030

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

3031

| O_NOFOLLOW

3032

| O_DIRECTORY

3033

| O_PATH));

2601

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

2602

O_NOFOLLOW));

3034

2603

if(tempdir_fd == -1){

3035

2604

perror_plus("open");

3036

2605

} else {

2606

#ifdef __GLIBC__

2607

#if __GLIBC_PREREQ(2, 15)

3037

2608

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

3038

2609

notdotentries, alphasort);

2610

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

2611

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

2612

alphasort);

2613

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

2614

#else /* not __GLIBC__ */

2615

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

2616

alphasort);

2617

#endif /* not __GLIBC__ */

3039

2618

if(numentries >= 0){

3040

2619

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

3041

2620

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

3044

2623

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

3045

2624

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

3046

2625

}

3047

free(direntries[i]);

3048

2626

}

3049

2627

3050

2628

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

3057

2635

perror_plus("rmdir");

3058

2636

}

3059

2637

}

3060

close(tempdir_fd);

2638

TEMP_FAILURE_RETRY(close(tempdir_fd));

3061

2639

}

3062

2640

}

3063

2641