/mandos/trunk : revision 871

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

46

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

47

strtof(), abort() */

48

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

49

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

50

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

49

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

50

asprintf(), strncpy(), strsignal()

51

*/

51

52

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

52

53

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

53

54

sockaddr_in6, PF_INET6,

57

58

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

58

59

inet_pton(), connect(),

59

60

getnameinfo() */

60

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

61

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

61

62

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

62

63

*/

63

64

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

64

65

strtoimax() */

65

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

66

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

67

EAI_SYSTEM, ENETUNREACH,

68

EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

66

71

program_invocation_short_name */

67

72

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

68

73

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

305

310

return false;

306

311

}

307

312

308

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

313

ret = close(fd);

309

314

if(ret == -1){

310

315

perror_plus("close");

311

316

}

493

498

return plaintext_length;

494

499

}

495

500

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

496

508

__attribute__((warn_unused_result))

497

509

static const char *safer_gnutls_strerror(int value){

498

510

const char *ret = gnutls_strerror(value);

499

if(ret == NULL)

500

ret = "(unknown)";

501

return ret;

511

return safe_string(ret);

502

512

}

503

513

504

514

/* GnuTLS log function callback */

508

518

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

509

519

}

510

520

511

__attribute__((nonnull, warn_unused_result))

521

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

512

522

static int init_gnutls_global(const char *pubkeyfilename,

513

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

514

525

mandos_context *mc){

515

526

int ret;

527

unsigned int uret;

516

528

517

529

if(debug){

518

530

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

519

531

}

520

532

521

ret = gnutls_global_init();

522

if(ret != GNUTLS_E_SUCCESS){

523

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

524

safer_gnutls_strerror(ret));

525

return -1;

526

}

527

528

533

if(debug){

529

534

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

530

535

* - GnuTLS manual

538

543

if(ret != GNUTLS_E_SUCCESS){

539

544

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

540

545

safer_gnutls_strerror(ret));

541

gnutls_global_deinit();

542

546

return -1;

543

547

}

544

548

569

573

safer_gnutls_strerror(ret));

570

574

goto globalfail;

571

575

}

572

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

573

if(ret != GNUTLS_E_SUCCESS){

574

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

575

safer_gnutls_strerror(ret));

576

goto globalfail;

577

}

578

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

} while(false);

630

}

631

if(dhparamsfilename == NULL){

632

if(mc->dh_bits == 0){

633

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

634

/* Try to read the private key file */

635

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

636

do {

637

int secfile = open(seckeyfilename, O_RDONLY);

638

if(secfile == -1){

639

perror_plus("open");

640

break;

641

}

642

size_t buffer_capacity = 0;

643

while(true){

644

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

645

(size_t)buffer.size,

646

(size_t)buffer_capacity);

647

if(buffer_capacity == 0){

648

perror_plus("incbuffer");

649

free(buffer.data);

650

buffer.data = NULL;

651

break;

652

}

653

ssize_t bytes_read = read(secfile,

654

buffer.data + buffer.size,

655

BUFFER_SIZE);

656

/* EOF */

657

if(bytes_read == 0){

658

break;

659

}

660

/* check bytes_read for failure */

661

if(bytes_read < 0){

662

perror_plus("read");

663

free(buffer.data);

664

buffer.data = NULL;

665

break;

666

}

667

buffer.size += (unsigned int)bytes_read;

668

}

669

close(secfile);

670

} while(false);

671

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

672

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

673

if(buffer.data != NULL){

674

{

675

gnutls_openpgp_privkey_t privkey = NULL;

676

ret = gnutls_openpgp_privkey_init(&privkey);

677

if(ret != GNUTLS_E_SUCCESS){

678

fprintf_plus(stderr, "Error initializing OpenPGP key"

679

" structure: %s",

680

safer_gnutls_strerror(ret));

681

free(buffer.data);

682

buffer.data = NULL;

683

} else {

684

ret = gnutls_openpgp_privkey_import

685

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

686

if(ret != GNUTLS_E_SUCCESS){

687

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

688

safer_gnutls_strerror(ret));

689

privkey = NULL;

690

}

691

free(buffer.data);

692

buffer.data = NULL;

693

if(privkey != NULL){

694

/* Use private key to suggest an appropriate

695

sec_param */

696

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

697

gnutls_openpgp_privkey_deinit(privkey);

698

if(debug){

699

fprintf_plus(stderr, "This OpenPGP key implies using"

700

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

701

safe_string(gnutls_sec_param_get_name

702

(sec_param)));

703

}

704

}

705

}

706

}

707

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

708

/* Err on the side of caution */

709

sec_param = GNUTLS_SEC_PARAM_ULTRA;

710

if(debug){

711

fprintf_plus(stderr, "Falling back to security parameter"

712

" \"%s\"\n",

713

safe_string(gnutls_sec_param_get_name

714

(sec_param)));

715

}

716

}

717

}

718

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

719

if(uret != 0){

720

mc->dh_bits = uret;

721

if(debug){

722

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

723

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

724

safe_string(gnutls_sec_param_get_name

725

(sec_param)),

726

mc->dh_bits);

727

}

728

} else {

729

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

730

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

731

safe_string(gnutls_sec_param_get_name

732

(sec_param)),

733

safer_gnutls_strerror(ret));

734

goto globalfail;

735

}

736

} else if(debug){

737

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

738

mc->dh_bits);

739

}

740

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

741

if(ret != GNUTLS_E_SUCCESS){

742

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

743

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

744

safer_gnutls_strerror(ret));

745

goto globalfail;

746

}

747

}

579

748

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

580

749

581

750

return 0;

583

752

globalfail:

584

753

585

754

gnutls_certificate_free_credentials(mc->cred);

586

gnutls_global_deinit();

587

755

gnutls_dh_params_deinit(mc->dh_params);

588

756

return -1;

589

757

}

641

809

/* ignore client certificate if any. */

642

810

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

643

811

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

645

646

812

return 0;

647

813

}

648

814

650

816

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

651

817

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

652

818

819

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

820

__attribute__((warn_unused_result))

821

int raise_privileges(void){

822

int old_errno = errno;

823

int ret = 0;

824

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

825

ret = errno;

826

}

827

errno = old_errno;

828

return ret;

829

}

830

831

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

832

__attribute__((warn_unused_result))

833

int raise_privileges_permanently(void){

834

int old_errno = errno;

835

int ret = raise_privileges();

836

if(ret != 0){

837

errno = old_errno;

838

return ret;

839

}

840

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

841

ret = errno;

842

}

843

errno = old_errno;

844

return ret;

845

}

846

847

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

848

__attribute__((warn_unused_result))

849

int lower_privileges(void){

850

int old_errno = errno;

851

int ret = 0;

852

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

853

ret = errno;

854

}

855

errno = old_errno;

856

return ret;

857

}

858

859

/* Lower privileges permanently */

860

__attribute__((warn_unused_result))

861

int lower_privileges_permanently(void){

862

int old_errno = errno;

863

int ret = 0;

864

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

865

ret = errno;

866

}

867

errno = old_errno;

868

return ret;

869

}

870

871

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

872

__attribute__((nonnull, warn_unused_result))

873

static bool add_delete_local_route(const bool add,

874

const char *address,

875

AvahiIfIndex if_index){

876

int ret;

877

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

878

char add_arg[] = "add";

879

char delete_arg[] = "delete";

880

char debug_flag[] = "--debug";

881

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

882

if(pluginhelperdir == NULL){

883

if(debug){

884

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

885

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

886

}

887

return false;

888

}

889

890

char interface[IF_NAMESIZE];

891

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

892

perror_plus("if_indextoname");

893

return false;

894

}

895

896

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

897

if(devnull == -1){

898

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

899

return false;

900

}

901

pid_t pid = fork();

902

if(pid == 0){

903

/* Child */

904

/* Raise privileges */

905

errno = raise_privileges_permanently();

906

if(errno != 0){

907

perror_plus("Failed to raise privileges");

908

/* _exit(EX_NOPERM); */

909

} else {

910

/* Set group */

911

errno = 0;

912

ret = setgid(0);

913

if(ret == -1){

914

perror_plus("setgid");

915

_exit(EX_NOPERM);

916

}

917

/* Reset supplementary groups */

918

errno = 0;

919

ret = setgroups(0, NULL);

920

if(ret == -1){

921

perror_plus("setgroups");

922

_exit(EX_NOPERM);

923

}

924

}

925

ret = dup2(devnull, STDIN_FILENO);

926

if(ret == -1){

927

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

928

_exit(EX_OSERR);

929

}

930

ret = close(devnull);

931

if(ret == -1){

932

perror_plus("close");

933

_exit(EX_OSERR);

934

}

935

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

936

if(ret == -1){

937

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

938

_exit(EX_OSERR);

939

}

940

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

941

O_RDONLY

942

| O_DIRECTORY

943

| O_PATH

944

| O_CLOEXEC));

945

if(helperdir_fd == -1){

946

perror_plus("open");

947

_exit(EX_UNAVAILABLE);

948

}

949

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

950

helper, O_RDONLY));

951

if(helper_fd == -1){

952

perror_plus("openat");

953

close(helperdir_fd);

954

_exit(EX_UNAVAILABLE);

955

}

956

close(helperdir_fd);

957

#ifdef __GNUC__

958

#pragma GCC diagnostic push

959

#pragma GCC diagnostic ignored "-Wcast-qual"

960

#endif

961

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

962

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

963

interface, debug ? debug_flag : NULL, NULL },

964

environ) == -1){

965

#ifdef __GNUC__

966

#pragma GCC diagnostic pop

967

#endif

968

perror_plus("fexecve");

969

_exit(EXIT_FAILURE);

970

}

971

}

972

if(pid == -1){

973

perror_plus("fork");

974

return false;

975

}

976

int status;

977

pid_t pret = -1;

978

errno = 0;

979

do {

980

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

981

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

982

int errno_raising = 0;

983

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

984

errno_raising = errno;

985

perror_plus("Failed to raise privileges in order to"

986

" kill helper program");

987

}

988

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

989

perror_plus("kill");

990

}

991

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

992

perror_plus("Failed to lower privileges after killing"

993

" helper program");

994

}

995

return false;

996

}

997

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

998

if(pret == -1){

999

perror_plus("waitpid");

1000

return false;

1001

}

1002

if(WIFEXITED(status)){

1003

if(WEXITSTATUS(status) != 0){

1004

fprintf_plus(stderr, "Error: iprouteadddel exited"

1005

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

1006

return false;

1007

}

1008

return true;

1009

}

1010

if(WIFSIGNALED(status)){

1011

fprintf_plus(stderr, "Error: iprouteadddel died by"

1012

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

1013

return false;

1014

}

1015

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

1016

return false;

1017

}

1018

1019

__attribute__((nonnull, warn_unused_result))

1020

static bool add_local_route(const char *address,

1021

AvahiIfIndex if_index){

1022

if(debug){

1023

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

1024

}

1025

return add_delete_local_route(true, address, if_index);

1026

}

1027

1028

__attribute__((nonnull, warn_unused_result))

1029

static bool delete_local_route(const char *address,

1030

AvahiIfIndex if_index){

1031

if(debug){

1032

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

1033

}

1034

return add_delete_local_route(false, address, if_index);

1035

}

1036

653

1037

/* Called when a Mandos server is found */

654

1038

__attribute__((nonnull, warn_unused_result))

655

1039

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

666

1050

int retval = -1;

667

1051

gnutls_session_t session;

668

1052

int pf; /* Protocol family */

1053

bool route_added = false;

669

1054

670

1055

errno = 0;

671

1056

729

1114

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

730

1115

}

731

1116

732

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

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

733

1118

if(tcp_sd < 0){

734

1119

int e = errno;

735

1120

perror_plus("socket");

742

1127

goto mandos_end;

743

1128

}

744

1129

745

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

746

1130

if(af == AF_INET6){

747

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

748

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

1131

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

1132

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

1133

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

749

1134

} else { /* IPv4 */

750

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

751

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

1135

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

1136

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

1137

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

752

1138

}

753

1139

if(ret < 0 ){

754

1140

int e = errno;

824

1210

goto mandos_end;

825

1211

}

826

1212

827

if(af == AF_INET6){

828

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

829

sizeof(struct sockaddr_in6));

830

} else {

831

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

832

sizeof(struct sockaddr_in));

833

}

834

if(ret < 0){

835

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

836

int e = errno;

837

perror_plus("connect");

838

errno = e;

839

}

840

goto mandos_end;

841

}

842

843

if(quit_now){

844

errno = EINTR;

845

goto mandos_end;

1213

while(true){

1214

if(af == AF_INET6){

1215

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

1216

sizeof(struct sockaddr_in6));

1217

} else {

1218

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

1219

sizeof(struct sockaddr_in));

1220

}

1221

if(ret < 0){

1222

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

1223

and if_index != AVAHI_IF_UNSPEC

1224

and connect_to == NULL

1225

and not route_added and

1226

((af == AF_INET6 and not

1227

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1228

&to)->sin6_addr)))

1229

or (af == AF_INET and

1230

/* Not a a IPv4LL address */

1231

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

1232

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

1233

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

1234

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

1235

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

1236

connect to a Mandos server announced by Avahi on a server

1237

host with a global address. Work around this by retrying

1238

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

1239

1240

Avahi bug reference:

1241

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

1242

https://bugs.debian.org/587961

1243

*/

1244

if(debug){

1245

fprintf_plus(stderr, "Mandos server unreachable, trying"

1246

" direct route\n");

1247

}

1248

int e = errno;

1249

route_added = add_local_route(ip, if_index);

1250

if(route_added){

1251

continue;

1252

}

1253

errno = e;

1254

}

1255

if(errno != ECONNREFUSED or debug){

1256

int e = errno;

1257

perror_plus("connect");

1258

errno = e;

1259

}

1260

goto mandos_end;

1261

}

1262

1263

if(quit_now){

1264

errno = EINTR;

1265

goto mandos_end;

1266

}

1267

break;

846

1268

}

847

1269

848

1270

const char *out = mandos_protocol_version;

1002

1424

&decrypted_buffer, mc);

1003

1425

if(decrypted_buffer_size >= 0){

1004

1426

1427

clearerr(stdout);

1005

1428

written = 0;

1006

1429

while(written < (size_t) decrypted_buffer_size){

1007

1430

if(quit_now){

1023

1446

}

1024

1447

written += (size_t)ret;

1025

1448

}

1449

ret = fflush(stdout);

1450

if(ret != 0){

1451

int e = errno;

1452

if(debug){

1453

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

1454

strerror(errno));

1455

}

1456

errno = e;

1457

goto mandos_end;

1458

}

1026

1459

retval = 0;

1027

1460

}

1028

1461

}

1031

1464

1032

1465

mandos_end:

1033

1466

{

1467

if(route_added){

1468

if(not delete_local_route(ip, if_index)){

1469

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

1470

" interface %d", ip, if_index);

1471

}

1472

}

1034

1473

int e = errno;

1035

1474

free(decrypted_buffer);

1036

1475

free(buffer);

1037

1476

if(tcp_sd >= 0){

1038

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

1477

ret = close(tcp_sd);

1039

1478

}

1040

1479

if(ret == -1){

1041

1480

if(e == 0){

1196

1635

__attribute__((nonnull, warn_unused_result))

1197

1636

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

1198

1637

int ret;

1199

error_t ret_errno;

1638

int old_errno;

1200

1639

1201

1640

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

1202

1641

if(s < 0){

1203

ret_errno = errno;

1642

old_errno = errno;

1204

1643

perror_plus("socket");

1205

errno = ret_errno;

1644

errno = old_errno;

1206

1645

return false;

1207

1646

}

1208

strcpy(ifr->ifr_name, ifname);

1647

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

1648

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

1209

1649

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1210

1650

if(ret == -1){

1211

1651

if(debug){

1212

ret_errno = errno;

1652

old_errno = errno;

1213

1653

perror_plus("ioctl SIOCGIFFLAGS");

1214

errno = ret_errno;

1654

errno = old_errno;

1215

1655

}

1216

1656

return false;

1217

1657

}

1462

1902

}

1463

1903

}

1464

1904

1465

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

1466

__attribute__((warn_unused_result))

1467

error_t raise_privileges(void){

1468

error_t old_errno = errno;

1469

error_t ret_errno = 0;

1470

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

1471

ret_errno = errno;

1472

}

1473

errno = old_errno;

1474

return ret_errno;

1475

}

1476

1477

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

1478

__attribute__((warn_unused_result))

1479

error_t raise_privileges_permanently(void){

1480

error_t old_errno = errno;

1481

error_t ret_errno = raise_privileges();

1482

if(ret_errno != 0){

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

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

1487

ret_errno = errno;

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

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

1494

__attribute__((warn_unused_result))

1495

error_t lower_privileges(void){

1496

error_t old_errno = errno;

1497

error_t ret_errno = 0;

1498

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

1499

ret_errno = errno;

1500

}

1501

errno = old_errno;

1502

return ret_errno;

1503

}

1504

1505

/* Lower privileges permanently */

1506

__attribute__((warn_unused_result))

1507

error_t lower_privileges_permanently(void){

1508

error_t old_errno = errno;

1509

error_t ret_errno = 0;

1510

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

1511

ret_errno = errno;

1512

}

1513

errno = old_errno;

1514

return ret_errno;

1515

}

1516

1517

1905

__attribute__((nonnull))

1518

1906

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

1519

1907

const float delay){

1520

1908

struct dirent **direntries = NULL;

1521

1909

if(hookdir_fd == -1){

1522

hookdir_fd = open(hookdir, O_RDONLY);

1910

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1911

| O_CLOEXEC);

1523

1912

if(hookdir_fd == -1){

1524

1913

if(errno == ENOENT){

1525

1914

if(debug){

1532

1921

return;

1533

1922

}

1534

1923

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

1537

1924

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

1538

1925

runnable_hook, alphasort);

1539

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

1540

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

1541

alphasort);

1542

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

1543

#else /* not __GLIBC__ */

1544

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

1545

alphasort);

1546

#endif /* not __GLIBC__ */

1547

1926

if(numhooks == -1){

1548

1927

perror_plus("scandir");

1549

1928

return;

1550

1929

}

1551

1930

struct dirent *direntry;

1552

1931

int ret;

1553

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

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1554

1937

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

1555

1938

direntry = direntries[i];

1556

1939

if(debug){

1580

1963

perror_plus("setgroups");

1581

1964

_exit(EX_NOPERM);

1582

1965

}

1583

ret = dup2(devnull, STDIN_FILENO);

1584

if(ret == -1){

1585

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

1586

_exit(EX_OSERR);

1587

}

1588

ret = close(devnull);

1589

if(ret == -1){

1590

perror_plus("close");

1591

_exit(EX_OSERR);

1592

}

1593

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1594

if(ret == -1){

1595

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

1596

_exit(EX_OSERR);

1597

}

1598

1966

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

1599

1967

if(ret == -1){

1600

1968

perror_plus("setenv");

1635

2003

_exit(EX_OSERR);

1636

2004

}

1637

2005

}

1638

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

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

1639

2009

if(hook_fd == -1){

1640

2010

perror_plus("openat");

1641

2011

_exit(EXIT_FAILURE);

1642

2012

}

1643

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

2013

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

1644

2014

perror_plus("close");

1645

2015

_exit(EXIT_FAILURE);

1646

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

ret = close(devnull);

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

1647

2032

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

1648

2033

environ) == -1){

1649

2034

perror_plus("fexecve");

1689

2074

free(direntry);

1690

2075

}

1691

2076

free(direntries);

1692

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

2077

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

1693

2078

perror_plus("close");

1694

2079

} else {

1695

2080

hookdir_fd = -1;

1698

2083

}

1699

2084

1700

2085

__attribute__((nonnull, warn_unused_result))

1701

error_t bring_up_interface(const char *const interface,

1702

const float delay){

1703

error_t old_errno = errno;

2086

int bring_up_interface(const char *const interface,

2087

const float delay){

2088

int old_errno = errno;

1704

2089

int ret;

1705

2090

struct ifreq network;

1706

2091

unsigned int if_index = if_nametoindex(interface);

1716

2101

}

1717

2102

1718

2103

if(not interface_is_up(interface)){

1719

error_t ret_errno = 0, ioctl_errno = 0;

2104

int ret_errno = 0;

2105

int ioctl_errno = 0;

1720

2106

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

1721

2107

ret_errno = errno;

1722

2108

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

1735

2121

}

1736

2122

1737

2123

if(quit_now){

1738

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

2124

ret = close(sd);

1739

2125

if(ret == -1){

1740

2126

perror_plus("close");

1741

2127

}

1791

2177

}

1792

2178

1793

2179

/* Close the socket */

1794

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

2180

ret = close(sd);

1795

2181

if(ret == -1){

1796

2182

perror_plus("close");

1797

2183

}

1825

2211

}

1826

2212

1827

2213

__attribute__((nonnull, warn_unused_result))

1828

error_t take_down_interface(const char *const interface){

1829

error_t old_errno = errno;

2214

int take_down_interface(const char *const interface){

2215

int old_errno = errno;

1830

2216

struct ifreq network;

1831

2217

unsigned int if_index = if_nametoindex(interface);

1832

2218

if(if_index == 0){

1835

2221

return ENXIO;

1836

2222

}

1837

2223

if(interface_is_up(interface)){

1838

error_t ret_errno = 0, ioctl_errno = 0;

2224

int ret_errno = 0;

2225

int ioctl_errno = 0;

1839

2226

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

1840

2227

ret_errno = errno;

1841

2228

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

1879

2266

}

1880

2267

1881

2268

/* Close the socket */

1882

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

2269

int ret = close(sd);

1883

2270

if(ret == -1){

1884

2271

perror_plus("close");

1885

2272

}

1900

2287

}

1901

2288

1902

2289

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

1903

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

1904

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

1905

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

1906

.interfaces = NULL, .interfaces_size = 0 };

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 };

1907

2295

AvahiSServiceBrowser *sb = NULL;

1908

2296

error_t ret_errno;

1909

2297

int ret;

1918

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1919

2307

const char *seckey = PATHDIR "/" SECKEY;

1920

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

1921

2310

char *interfaces_hooks = NULL;

1922

2311

1923

2312

bool gnutls_initialized = false;

1976

2365

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

1977

2366

" Diffie-Hellman key exchange",

1978

2367

.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 },

1979

2373

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

1980

2374

.arg = "STRING",

1981

2375

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

2036

2430

}

2037

2431

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

2038

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2039

2436

case 130: /* --priority */

2040

2437

mc.priority = arg;

2041

2438

break;

2081

2478

.args_doc = "",

2082

2479

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

2083

2480

" passwords from a Mandos server" };

2084

ret = argp_parse(&argp, argc, argv,

2085

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2086

switch(ret){

2481

ret_errno = argp_parse(&argp, argc, argv,

2482

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2483

switch(ret_errno){

2087

2484

case 0:

2088

2485

break;

2089

2486

case ENOMEM:

2090

2487

default:

2091

errno = ret;

2488

errno = ret_errno;

2092

2489

perror_plus("argp_parse");

2093

2490

exitcode = EX_OSERR;

2094

2491

goto end;

2097

2494

goto end;

2098

2495

}

2099

2496

}

2100

2497

2101

2498

{

2102

2499

/* Work around Debian bug #633582:

2103

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

2500

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

2104

2501

2105

2502

/* Re-raise privileges */

2106

ret_errno = raise_privileges();

2107

if(ret_errno != 0){

2108

errno = ret_errno;

2503

ret = raise_privileges();

2504

if(ret != 0){

2505

errno = ret;

2109

2506

perror_plus("Failed to raise privileges");

2110

2507

} else {

2111

2508

struct stat st;

2127

2524

}

2128

2525

}

2129

2526

}

2130

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

close(seckey_fd);

2131

2528

}

2132

2529

}

2133

2530

2134

2531

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

2135

2532

int pubkey_fd = open(pubkey, O_RDONLY);

2136

2533

if(pubkey_fd == -1){

2148

2545

}

2149

2546

}

2150

2547

}

2151

TEMP_FAILURE_RETRY(close(pubkey_fd));

2152

}

2153

}

2154

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

2155

2574

/* Lower privileges */

2156

ret_errno = lower_privileges();

2157

if(ret_errno != 0){

2158

errno = ret_errno;

2575

ret = lower_privileges();

2576

if(ret != 0){

2577

errno = ret;

2159

2578

perror_plus("Failed to lower privileges");

2160

2579

}

2161

2580

}

2331

2750

errno = bring_up_interface(interface, delay);

2332

2751

if(not interface_was_up){

2333

2752

if(errno != 0){

2334

perror_plus("Failed to bring up interface");

2753

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

2754

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

2335

2755

} else {

2336

2756

errno = argz_add(&interfaces_to_take_down,

2337

2757

&interfaces_to_take_down_size,

2360

2780

goto end;

2361

2781

}

2362

2782

2363

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

2783

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

2364

2784

if(ret == -1){

2365

2785

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

2366

2786

exitcode = EX_UNAVAILABLE;

2488

2908

2489

2909

/* Allocate a new server */

2490

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2491

&config, NULL, NULL, &ret_errno);

2911

&config, NULL, NULL, &ret);

2492

2912

2493

2913

/* Free the Avahi configuration data */

2494

2914

avahi_server_config_free(&config);

2497

2917

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

2498

2918

if(mc.server == NULL){

2499

2919

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

2500

avahi_strerror(ret_errno));

2920

avahi_strerror(ret));

2501

2921

exitcode = EX_UNAVAILABLE;

2502

2922

goto end;

2503

2923

}

2538

2958

end:

2539

2959

2540

2960

if(debug){

2541

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

2961

if(signal_received){

2962

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

2963

argv[0], signal_received,

2964

strsignal(signal_received));

2965

} else {

2966

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

2967

}

2542

2968

}

2543

2969

2544

2970

/* Cleanup things */

2555

2981

2556

2982

if(gnutls_initialized){

2557

2983

gnutls_certificate_free_credentials(mc.cred);

2558

gnutls_global_deinit();

2559

2984

gnutls_dh_params_deinit(mc.dh_params);

2560

2985

}

2561

2986

2584

3009

2585

3010

/* Re-raise privileges */

2586

3011

{

2587

ret_errno = raise_privileges();

2588

if(ret_errno != 0){

2589

errno = ret_errno;

3012

ret = raise_privileges();

3013

if(ret != 0){

3014

errno = ret;

2590

3015

perror_plus("Failed to raise privileges");

2591

3016

} else {

2592

3017

2600

3025

while((interface=argz_next(interfaces_to_take_down,

2601

3026

interfaces_to_take_down_size,

2602

3027

interface))){

2603

ret_errno = take_down_interface(interface);

2604

if(ret_errno != 0){

2605

errno = ret_errno;

3028

ret = take_down_interface(interface);

3029

if(ret != 0){

3030

errno = ret;

2606

3031

perror_plus("Failed to take down interface");

2607

3032

}

2608

3033

}

2613

3038

}

2614

3039

}

2615

3040

2616

ret_errno = lower_privileges_permanently();

2617

if(ret_errno != 0){

2618

errno = ret_errno;

3041

ret = lower_privileges_permanently();

3042

if(ret != 0){

3043

errno = ret;

2619

3044

perror_plus("Failed to lower privileges permanently");

2620

3045

}

2621

3046

}

2623

3048

free(interfaces_to_take_down);

2624

3049

free(interfaces_hooks);

2625

3050

3051

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

3052

uintmax_t level){

3053

struct dirent **direntries = NULL;

3054

int dret;

3055

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

3056

O_RDONLY

3057

| O_NOFOLLOW

3058

| O_DIRECTORY

3059

| O_PATH));

3060

if(dir_fd == -1){

3061

perror_plus("open");

3062

}

3063

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

3064

notdotentries, alphasort);

3065

if(numentries >= 0){

3066

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

3067

if(debug){

3068

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

3069

dirname, direntries[i]->d_name);

3070

}

3071

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

3072

if(dret == -1){

3073

if(errno == EISDIR){

3074

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

3075

AT_REMOVEDIR);

3076

}

3077

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

3078

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

3079

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

3080

/* Recurse only in this special case */

3081

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

3082

dret = 0;

3083

}

3084

if(dret == -1){

3085

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

3086

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

3087

}

3088

}

3089

free(direntries[i]);

3090

}

3091

3092

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

3093

free(direntries);

3094

if(numentries == -1){

3095

perror_plus("scandirat");

3096

}

3097

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3098

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

3099

perror_plus("rmdir");

3100

}

3101

} else {

3102

perror_plus("scandirat");

3103

}

3104

close(dir_fd);

3105

}

3106

2626

3107

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

2627

3108

if(tempdir != NULL){

2628

struct dirent **direntries = NULL;

2629

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

2630

O_NOFOLLOW));

2631

if(tempdir_fd == -1){

2632

perror_plus("open");

2633

} else {

2634

#ifdef __GLIBC__

2635

#if __GLIBC_PREREQ(2, 15)

2636

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

2637

notdotentries, alphasort);

2638

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

2639

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

2640

alphasort);

2641

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

2642

#else /* not __GLIBC__ */

2643

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

2644

alphasort);

2645

#endif /* not __GLIBC__ */

2646

if(numentries >= 0){

2647

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

2648

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

2649

if(ret == -1){

2650

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

2651

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

2652

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

2653

}

2654

free(direntries[i]);

2655

}

2656

2657

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

2658

free(direntries);

2659

if(numentries == -1){

2660

perror_plus("scandir");

2661

}

2662

ret = rmdir(tempdir);

2663

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

2664

perror_plus("rmdir");

2665

}

2666

}

2667

TEMP_FAILURE_RETRY(close(tempdir_fd));

2668

}

3109

clean_dir_at(-1, tempdir, 0);

2669

3110

}

2670

3111

2671

3112

if(quit_now){