/mandos/trunk : revision 748

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,

305

return false;

306

}

307

308

ret = close(fd);

308

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

309

if(ret == -1){

310

perror_plus("close");

311

}

516

__attribute__((nonnull, warn_unused_result))

517

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

519

mandos_context *mc){

521

520

int ret;

522

521

unsigned int uret;

576

575

safer_gnutls_strerror(ret));

577

576

goto globalfail;

578

577

}

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;

578

if(mc->dh_bits == 0){

579

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

580

/* Try to read the private key file */

581

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

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

590

585

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

586

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

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

595

590

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

591

free(buffer.data);

592

buffer.data = NULL;

599

593

break;

600

594

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

603

596

BUFFER_SIZE);

604

597

/* EOF */

605

598

if(bytes_read == 0){

608

601

/* check bytes_read for failure */

609

602

if(bytes_read < 0){

610

603

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);

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

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

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

680

627

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

628

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

683

629

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

}

630

privkey = NULL;

708

631

}

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)));

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

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

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

718

644

}

719

645

}

720

646

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

724

650

if(debug){

725

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

726

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

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

727

653

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

654

(sec_param)));

730

655

}

731

} else {

732

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

733

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

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

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

663

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

734

664

safe_string(gnutls_sec_param_get_name

735

665

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

666

mc->dh_bits);

738

667

}

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,

668

} else {

669

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

670

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

671

safe_string(gnutls_sec_param_get_name(sec_param)),

747

672

safer_gnutls_strerror(ret));

748

673

goto globalfail;

749

674

}

750

}

675

} else if(debug){

676

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

677

mc->dh_bits);

678

}

679

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

680

if(ret != GNUTLS_E_SUCCESS){

681

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

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

683

goto globalfail;

684

}

685

751

686

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

752

687

753

688

return 0;

813

748

/* ignore client certificate if any. */

814

749

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

750

751

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

752

816

753

return 0;

817

754

}

818

755

820

757

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

821

758

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

822

759

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

760

/* Called when a Mandos server is found */

1042

761

__attribute__((nonnull, warn_unused_result))

1043

762

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

1054

773

int retval = -1;

1055

774

gnutls_session_t session;

1056

775

int pf; /* Protocol family */

1057

bool route_added = false;

1058

776

1059

777

errno = 0;

1060

778

1118

836

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

1119

837

}

1120

838

1121

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

839

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

840

if(tcp_sd < 0){

1123

841

int e = errno;

1124

842

perror_plus("socket");

1131

849

goto mandos_end;

1132

850

}

1133

851

852

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

1134

853

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);

854

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

855

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

1138

856

} 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);

857

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

858

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

1142

859

}

1143

860

if(ret < 0 ){

1144

861

int e = errno;

1214

931

goto mandos_end;

1215

932

}

1216

933

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) or (errno == EHOSTUNREACH))

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;

934

if(af == AF_INET6){

935

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

936

sizeof(struct sockaddr_in6));

937

} else {

938

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

939

sizeof(struct sockaddr_in));

940

}

941

if(ret < 0){

942

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

943

int e = errno;

944

perror_plus("connect");

945

errno = e;

946

}

947

goto mandos_end;

948

}

949

950

if(quit_now){

951

errno = EINTR;

952

goto mandos_end;

1272

953

}

1273

954

1274

955

const char *out = mandos_protocol_version;

1457

1138

1458

1139

mandos_end:

1459

1140

{

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

1141

int e = errno;

1467

1142

free(decrypted_buffer);

1468

1143

free(buffer);

1469

1144

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

1145

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

1471

1146

}

1472

1147

if(ret == -1){

1473

1148

if(e == 0){

1637

1312

errno = ret_errno;

1638

1313

return false;

1639

1314

}

1640

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

1641

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

1315

strcpy(ifr->ifr_name, ifname);

1642

1316

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1643

1317

if(ret == -1){

1644

1318

if(debug){

1895

1569

}

1896

1570

}

1897

1571

1572

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

1573

__attribute__((warn_unused_result))

1574

error_t raise_privileges(void){

1575

error_t old_errno = errno;

1576

error_t ret_errno = 0;

1577

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

1578

ret_errno = errno;

1579

}

1580

errno = old_errno;

1581

return ret_errno;

1582

}

1583

1584

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

1585

__attribute__((warn_unused_result))

1586

error_t raise_privileges_permanently(void){

1587

error_t old_errno = errno;

1588

error_t ret_errno = raise_privileges();

1589

if(ret_errno != 0){

1590

errno = old_errno;

1591

return ret_errno;

1592

}

1593

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

1594

ret_errno = errno;

1595

}

1596

errno = old_errno;

1597

return ret_errno;

1598

}

1599

1600

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

1601

__attribute__((warn_unused_result))

1602

error_t lower_privileges(void){

1603

error_t old_errno = errno;

1604

error_t ret_errno = 0;

1605

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

1606

ret_errno = errno;

1607

}

1608

errno = old_errno;

1609

return ret_errno;

1610

}

1611

1612

/* Lower privileges permanently */

1613

__attribute__((warn_unused_result))

1614

error_t lower_privileges_permanently(void){

1615

error_t old_errno = errno;

1616

error_t ret_errno = 0;

1617

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

1618

ret_errno = errno;

1619

}

1620

errno = old_errno;

1621

return ret_errno;

1622

}

1623

1898

1624

__attribute__((nonnull))

1899

1625

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

1900

1626

const float delay){

1901

1627

struct dirent **direntries = NULL;

1902

1628

if(hookdir_fd == -1){

1903

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1904

| O_CLOEXEC);

1629

hookdir_fd = open(hookdir, O_RDONLY);

1905

1630

if(hookdir_fd == -1){

1906

1631

if(errno == ENOENT){

1907

1632

if(debug){

1932

1657

}

1933

1658

struct dirent *direntry;

1934

1659

int ret;

1935

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

1936

if(devnull == -1){

1937

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

1938

return;

1939

}

1660

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

1940

1661

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

1941

1662

direntry = direntries[i];

1942

1663

if(debug){

1966

1687

perror_plus("setgroups");

1967

1688

_exit(EX_NOPERM);

1968

1689

}

1690

ret = dup2(devnull, STDIN_FILENO);

1691

if(ret == -1){

1692

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

1693

_exit(EX_OSERR);

1694

}

1695

ret = close(devnull);

1696

if(ret == -1){

1697

perror_plus("close");

1698

_exit(EX_OSERR);

1699

}

1700

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1701

if(ret == -1){

1702

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

1703

_exit(EX_OSERR);

1704

}

1969

1705

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

1970

1706

if(ret == -1){

1971

1707

perror_plus("setenv");

2006

1742

_exit(EX_OSERR);

2007

1743

}

2008

1744

}

2009

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

2010

direntry->d_name,

2011

O_RDONLY));

1745

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

2012

1746

if(hook_fd == -1){

2013

1747

perror_plus("openat");

2014

1748

_exit(EXIT_FAILURE);

2015

1749

}

2016

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

1750

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

2017

1751

perror_plus("close");

2018

1752

_exit(EXIT_FAILURE);

2019

1753

}

2020

ret = dup2(devnull, STDIN_FILENO);

2021

if(ret == -1){

2022

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

2023

_exit(EX_OSERR);

2024

}

2025

ret = close(devnull);

2026

if(ret == -1){

2027

perror_plus("close");

2028

_exit(EX_OSERR);

2029

}

2030

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2031

if(ret == -1){

2032

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

2033

_exit(EX_OSERR);

2034

}

2035

1754

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

2036

1755

environ) == -1){

2037

1756

perror_plus("fexecve");

2077

1796

free(direntry);

2078

1797

}

2079

1798

free(direntries);

2080

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

1799

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

2081

1800

perror_plus("close");

2082

1801

} else {

2083

1802

hookdir_fd = -1;

2123

1842

}

2124

1843

2125

1844

if(quit_now){

2126

ret = close(sd);

1845

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

2127

1846

if(ret == -1){

2128

1847

perror_plus("close");

2129

1848

}

2179

1898

}

2180

1899

2181

1900

/* Close the socket */

2182

ret = close(sd);

1901

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

2183

1902

if(ret == -1){

2184

1903

perror_plus("close");

2185

1904

}

2267

1986

}

2268

1987

2269

1988

/* Close the socket */

2270

int ret = close(sd);

1989

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

2271

1990

if(ret == -1){

2272

1991

perror_plus("close");

2273

1992

}

2289

2008

2290

2009

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

2291

2010

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

2011

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

2012

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2013

.interfaces = NULL, .interfaces_size = 0 };

2296

2014

AvahiSServiceBrowser *sb = NULL;

2297

2015

error_t ret_errno;

2298

2016

int ret;

2307

2025

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

2026

const char *seckey = PATHDIR "/" SECKEY;

2309

2027

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

2028

char *interfaces_hooks = NULL;

2312

2029

2313

2030

bool gnutls_initialized = false;

2366

2083

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

2367

2084

" Diffie-Hellman key exchange",

2368

2085

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

2374

2086

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

2375

2087

.arg = "STRING",

2376

2088

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

2431

2143

}

2432

2144

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

2433

2145

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

2146

case 130: /* --priority */

2438

2147

mc.priority = arg;

2439

2148

break;

2495

2204

goto end;

2496

2205

}

2497

2206

}

2498

2207

2499

2208

{

2500

2209

/* Work around Debian bug #633582:

2501

2210

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

2525

2234

}

2526

2235

}

2527

2236

}

2528

close(seckey_fd);

2237

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

2238

}

2530

2239

}

2531

2240

2532

2241

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

2533

2242

int pubkey_fd = open(pubkey, O_RDONLY);

2534

2243

if(pubkey_fd == -1){

2546

2255

}

2547

2256

}

2548

2257

}

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

2258

TEMP_FAILURE_RETRY(close(pubkey_fd));

2259

}

2260

}

2261

2575

2262

/* Lower privileges */

2576

2263

ret_errno = lower_privileges();

2577

2264

if(ret_errno != 0){

2751

2438

errno = bring_up_interface(interface, delay);

2752

2439

if(not interface_was_up){

2753

2440

if(errno != 0){

2754

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

2755

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

2441

perror_plus("Failed to bring up interface");

2756

2442

} else {

2757

2443

errno = argz_add(&interfaces_to_take_down,

2758

2444

&interfaces_to_take_down_size,

2781

2467

goto end;

2782

2468

}

2783

2469

2784

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

2470

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

2785

2471

if(ret == -1){

2786

2472

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

2787

2473

exitcode = EX_UNAVAILABLE;

3047

2733

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

3048

2734

if(tempdir != NULL){

3049

2735

struct dirent **direntries = NULL;

3050

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

3051

| O_NOFOLLOW

3052

| O_DIRECTORY

3053

| O_PATH));

2736

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

2737

O_NOFOLLOW));

3054

2738

if(tempdir_fd == -1){

3055

2739

perror_plus("open");

3056

2740

} else {

3087

2771

perror_plus("rmdir");

3088

2772

}

3089

2773

}

3090

close(tempdir_fd);

2774

TEMP_FAILURE_RETRY(close(tempdir_fd));

3091

2775

}

3092

2776

}

3093

2777