32
32
#define _LARGEFILE_SOURCE
33
33
#define _FILE_OFFSET_BITS 64
35
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
37
#include <stdio.h> /* fprintf(), stderr, fwrite(), stdout,
39
#include <stdint.h> /* uint16_t, uint32_t */
40
#include <stddef.h> /* NULL, size_t, ssize_t */
41
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
43
#include <stdbool.h> /* bool, true */
44
#include <string.h> /* memset(), strcmp(), strlen(),
45
strerror(), memcpy(), strcpy() */
46
#include <sys/ioctl.h> /* ioctl */
47
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
48
sockaddr_in6, PF_INET6,
49
SOCK_STREAM, INET6_ADDRSTRLEN,
51
#include <inttypes.h> /* PRIu16 */
52
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
53
struct in6_addr, inet_pton(),
55
#include <assert.h> /* assert() */
56
#include <errno.h> /* perror(), errno */
57
#include <time.h> /* time() */
39
#include <net/if.h> /* if_nametoindex */
40
#include <sys/ioctl.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
58
42
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
59
SIOCSIFFLAGS, if_indextoname(),
60
if_nametoindex(), IF_NAMESIZE */
61
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
62
getuid(), getgid(), setuid(),
64
#include <netinet/in.h>
65
#include <arpa/inet.h> /* inet_pton(), htons */
66
#include <iso646.h> /* not, and */
67
#include <argp.h> /* struct argp_option, error_t, struct
68
argp_state, struct argp,
69
argp_parse(), ARGP_KEY_ARG,
70
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
73
/* All Avahi types, constants and functions
76
45
#include <avahi-core/core.h>
77
46
#include <avahi-core/lookup.h>
78
47
#include <avahi-core/log.h>
80
49
#include <avahi-common/malloc.h>
81
50
#include <avahi-common/error.h>
84
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and functions
86
init_gnutls_session(),
88
#include <gnutls/openpgp.h> /* gnutls_certificate_set_openpgp_key_file(),
89
GNUTLS_OPENPGP_FMT_BASE64 */
92
#include <gpgme.h> /* All GPGME types, constants and functions
94
GPGME_PROTOCOL_OpenPGP,
53
#include <sys/types.h> /* socket(), inet_pton() */
54
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
55
struct in6_addr, inet_pton() */
56
#include <gnutls/gnutls.h> /* All GnuTLS stuff */
57
#include <gnutls/openpgp.h> /* GnuTLS with openpgp stuff */
59
#include <unistd.h> /* close() */
60
#include <netinet/in.h>
61
#include <stdbool.h> /* true */
62
#include <string.h> /* memset */
63
#include <arpa/inet.h> /* inet_pton() */
64
#include <iso646.h> /* not */
67
#include <errno.h> /* perror() */
97
73
#define BUFFER_SIZE 256
75
static const char *keydir = "/conf/conf.d/mandos";
76
static const char *pubkeyfile = "pubkey.txt";
77
static const char *seckeyfile = "seckey.txt";
99
79
bool debug = false;
100
static const char *keydir = "/conf/conf.d/mandos";
101
static const char mandos_protocol_version[] = "1";
102
const char *argp_program_version = "password-request 1.0";
103
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
105
/* Used for passing in values through the Avahi callback functions */
81
/* Used for passing in values through all the callback functions */
107
83
AvahiSimplePoll *simple_poll;
108
84
AvahiServer *server;
109
85
gnutls_certificate_credentials_t cred;
110
86
unsigned int dh_bits;
111
gnutls_dh_params_t dh_params;
112
87
const char *priority;
116
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
117
* "buffer_capacity" is how much is currently allocated,
118
* "buffer_length" is how much is already used.
120
size_t adjustbuffer(char **buffer, size_t buffer_length,
121
size_t buffer_capacity){
122
if (buffer_length + BUFFER_SIZE > buffer_capacity){
123
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
127
buffer_capacity += BUFFER_SIZE;
129
return buffer_capacity;
133
91
* Decrypt OpenPGP data using keyrings in HOMEDIR.
134
92
* Returns -1 on error
309
/* GnuTLS log function callback */
310
270
static void debuggnutls(__attribute__((unused)) int level,
311
271
const char* string){
312
fprintf(stderr, "GnuTLS: %s", string);
272
fprintf(stderr, "%s", string);
315
static int init_gnutls_global(mandos_context *mc,
316
const char *pubkeyfile,
317
const char *seckeyfile){
275
static int initgnutls(mandos_context *mc, gnutls_session_t *session,
276
gnutls_dh_params_t *dh_params){
321
281
fprintf(stderr, "Initializing GnuTLS\n");
324
ret = gnutls_global_init();
325
if (ret != GNUTLS_E_SUCCESS) {
326
fprintf (stderr, "GnuTLS global_init: %s\n",
327
safer_gnutls_strerror(ret));
284
if ((ret = gnutls_global_init ())
285
!= GNUTLS_E_SUCCESS) {
286
fprintf (stderr, "global_init: %s\n", safer_gnutls_strerror(ret));
332
/* "Use a log level over 10 to enable all debugging options."
335
291
gnutls_global_set_log_level(11);
336
292
gnutls_global_set_log_function(debuggnutls);
339
/* OpenPGP credentials */
340
gnutls_certificate_allocate_credentials(&mc->cred);
341
if (ret != GNUTLS_E_SUCCESS){
342
fprintf (stderr, "GnuTLS memory error: %s\n",
295
/* openpgp credentials */
296
if ((ret = gnutls_certificate_allocate_credentials (&mc->cred))
297
!= GNUTLS_E_SUCCESS) {
298
fprintf (stderr, "memory error: %s\n",
343
299
safer_gnutls_strerror(ret));
344
gnutls_global_deinit ();
354
309
ret = gnutls_certificate_set_openpgp_key_file
355
310
(mc->cred, pubkeyfile, seckeyfile, GNUTLS_OPENPGP_FMT_BASE64);
356
311
if (ret != GNUTLS_E_SUCCESS) {
358
"Error[%d] while reading the OpenPGP key pair ('%s',"
359
" '%s')\n", ret, pubkeyfile, seckeyfile);
360
fprintf(stdout, "The GnuTLS error is: %s\n",
313
(stderr, "Error[%d] while reading the OpenPGP key pair ('%s',"
315
ret, pubkeyfile, seckeyfile);
316
fprintf(stdout, "The Error is: %s\n",
361
317
safer_gnutls_strerror(ret));
365
/* GnuTLS server initialization */
366
ret = gnutls_dh_params_init(&mc->dh_params);
367
if (ret != GNUTLS_E_SUCCESS) {
368
fprintf (stderr, "Error in GnuTLS DH parameter initialization:"
369
" %s\n", safer_gnutls_strerror(ret));
372
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
373
if (ret != GNUTLS_E_SUCCESS) {
374
fprintf (stderr, "Error in GnuTLS prime generation: %s\n",
375
safer_gnutls_strerror(ret));
379
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
385
gnutls_certificate_free_credentials(mc->cred);
386
gnutls_global_deinit();
391
static int init_gnutls_session(mandos_context *mc,
392
gnutls_session_t *session){
394
/* GnuTLS session creation */
395
ret = gnutls_init(session, GNUTLS_SERVER);
396
if (ret != GNUTLS_E_SUCCESS){
321
//GnuTLS server initialization
322
if ((ret = gnutls_dh_params_init(dh_params))
323
!= GNUTLS_E_SUCCESS) {
324
fprintf (stderr, "Error in dh parameter initialization: %s\n",
325
safer_gnutls_strerror(ret));
329
if ((ret = gnutls_dh_params_generate2(*dh_params, mc->dh_bits))
330
!= GNUTLS_E_SUCCESS) {
331
fprintf (stderr, "Error in prime generation: %s\n",
332
safer_gnutls_strerror(ret));
336
gnutls_certificate_set_dh_params(mc->cred, *dh_params);
338
// GnuTLS session creation
339
if ((ret = gnutls_init(session, GNUTLS_SERVER))
340
!= GNUTLS_E_SUCCESS){
397
341
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
398
342
safer_gnutls_strerror(ret));
403
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
404
if (ret != GNUTLS_E_SUCCESS) {
405
fprintf(stderr, "Syntax error at: %s\n", err);
406
fprintf(stderr, "GnuTLS error: %s\n",
407
safer_gnutls_strerror(ret));
408
gnutls_deinit (*session);
345
if ((ret = gnutls_priority_set_direct(*session, mc->priority, &err))
346
!= GNUTLS_E_SUCCESS) {
347
fprintf(stderr, "Syntax error at: %s\n", err);
348
fprintf(stderr, "GnuTLS error: %s\n",
349
safer_gnutls_strerror(ret));
413
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
415
if (ret != GNUTLS_E_SUCCESS) {
416
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
353
if ((ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
355
!= GNUTLS_E_SUCCESS) {
356
fprintf(stderr, "Error setting a credentials set: %s\n",
417
357
safer_gnutls_strerror(ret));
418
gnutls_deinit (*session);
431
/* Avahi log function callback */
432
370
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
433
371
__attribute__((unused)) const char *txt){}
435
/* Called when a Mandos server is found */
436
373
static int start_mandos_communication(const char *ip, uint16_t port,
437
374
AvahiIfIndex if_index,
438
375
mandos_context *mc){
440
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
377
struct sockaddr_in6 to;
441
378
char *buffer = NULL;
442
379
char *decrypted_buffer;
443
380
size_t buffer_length = 0;
444
381
size_t buffer_capacity = 0;
445
382
ssize_t decrypted_buffer_size;
448
385
char interface[IF_NAMESIZE];
449
386
gnutls_session_t session;
451
ret = init_gnutls_session (mc, &session);
387
gnutls_dh_params_t dh_params;
457
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
390
fprintf(stderr, "Setting up a tcp connection to %s, port %d\n",
461
394
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
506
ret = connect(tcp_sd, &to.in, sizeof(to));
436
ret = connect(tcp_sd, (struct sockaddr *) &to, sizeof(to));
508
438
perror("connect");
512
const char *out = mandos_protocol_version;
515
size_t out_size = strlen(out);
516
ret = TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
517
out_size - written));
523
written += (size_t)ret;
524
if(written < out_size){
527
if (out == mandos_protocol_version){
442
ret = initgnutls (mc, &session, &dh_params);
448
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
537
451
fprintf(stderr, "Establishing TLS session with %s\n", ip);
540
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
543
ret = gnutls_handshake (session);
544
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
454
ret = gnutls_handshake (session);
546
456
if (ret != GNUTLS_E_SUCCESS){
548
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
458
fprintf(stderr, "\n*** Handshake failed ***\n");
549
459
gnutls_perror (ret);
555
/* Read OpenPGP packet that contains the wanted password */
465
//Retrieve OpenPGP packet that contains the wanted password
558
468
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
579
490
case GNUTLS_E_AGAIN:
581
492
case GNUTLS_E_REHANDSHAKE:
583
ret = gnutls_handshake (session);
584
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
493
ret = gnutls_handshake (session);
586
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
495
fprintf(stderr, "\n*** Handshake failed ***\n");
587
496
gnutls_perror (ret);
593
502
fprintf(stderr, "Unknown error while reading data from"
594
" encrypted session with Mandos server\n");
503
" encrypted session with mandos server\n");
596
505
gnutls_bye (session, GNUTLS_SHUT_RDWR);
600
509
buffer_length += (size_t) ret;
605
fprintf(stderr, "Closing TLS session\n");
608
gnutls_bye (session, GNUTLS_SHUT_RDWR);
610
513
if (buffer_length > 0){
611
514
decrypted_buffer_size = pgp_packet_decrypt(buffer,
613
516
&decrypted_buffer,
615
518
if (decrypted_buffer_size >= 0){
617
519
while(written < (size_t) decrypted_buffer_size){
618
520
ret = (int)fwrite (decrypted_buffer + written, 1,
619
521
(size_t)decrypted_buffer_size - written,
710
618
case AVAHI_BROWSER_FAILURE:
712
fprintf(stderr, "(Avahi browser) %s\n",
620
fprintf(stderr, "(Browser) %s\n",
713
621
avahi_strerror(avahi_server_errno(mc->server)));
714
622
avahi_simple_poll_quit(mc->simple_poll);
717
625
case AVAHI_BROWSER_NEW:
718
/* We ignore the returned Avahi resolver object. In the callback
719
function we free it. If the Avahi server is terminated before
720
the callback function is called the Avahi server will free the
626
/* We ignore the returned resolver object. In the callback
627
function we free it. If the server is terminated before
628
the callback function is called the server will free
629
the resolver for us. */
723
631
if (!(avahi_s_service_resolver_new(mc->server, interface,
724
632
protocol, name, type, domain,
725
633
AVAHI_PROTO_INET6, 0,
726
634
resolve_callback, mc)))
727
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
728
name, avahi_strerror(avahi_server_errno(mc->server)));
635
fprintf(stderr, "Failed to resolve service '%s': %s\n", name,
636
avahi_strerror(avahi_server_errno(mc->server)));
731
639
case AVAHI_BROWSER_REMOVE:
764
int main(int argc, char *argv[]){
669
int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char*argv[]) {
670
AvahiServerConfig config;
765
671
AvahiSServiceBrowser *sb = NULL;
768
int exitcode = EXIT_SUCCESS;
675
int returncode = EXIT_SUCCESS;
769
676
const char *interface = "eth0";
770
677
struct ifreq network;
774
679
char *connect_to = NULL;
775
680
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
776
const char *pubkeyfile = "pubkey.txt";
777
const char *seckeyfile = "seckey.txt";
778
681
mandos_context mc = { .simple_poll = NULL, .server = NULL,
779
682
.dh_bits = 1024, .priority = "SECURE256"};
780
bool gnutls_initalized = false;
783
struct argp_option options[] = {
784
{ .name = "debug", .key = 128,
785
.doc = "Debug mode", .group = 3 },
786
{ .name = "connect", .key = 'c',
788
.doc = "Connect directly to a sepcified mandos server",
790
{ .name = "interface", .key = 'i',
792
.doc = "Interface that Avahi will conntect through",
794
{ .name = "keydir", .key = 'd',
796
.doc = "Directory where the openpgp keyring is",
798
{ .name = "seckey", .key = 's',
800
.doc = "Secret openpgp key for gnutls authentication",
802
{ .name = "pubkey", .key = 'p',
804
.doc = "Public openpgp key for gnutls authentication",
806
{ .name = "dh-bits", .key = 129,
808
.doc = "dh-bits to use in gnutls communication",
810
{ .name = "priority", .key = 130,
812
.doc = "GNUTLS priority", .group = 1 },
817
error_t parse_opt (int key, char *arg,
818
struct argp_state *state) {
819
/* Get the INPUT argument from `argp_parse', which we know is
820
a pointer to our plugin list pointer. */
842
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
857
return ARGP_ERR_UNKNOWN;
684
debug_int = debug ? 1 : 0;
686
struct option long_options[] = {
687
{"debug", no_argument, &debug_int, 1},
688
{"connect", required_argument, NULL, 'c'},
689
{"interface", required_argument, NULL, 'i'},
690
{"keydir", required_argument, NULL, 'd'},
691
{"seckey", required_argument, NULL, 's'},
692
{"pubkey", required_argument, NULL, 'p'},
693
{"dh-bits", required_argument, NULL, 'D'},
694
{"priority", required_argument, NULL, 'P'},
697
int option_index = 0;
698
ret = getopt_long (argc, argv, "i:", long_options,
725
mc.dh_bits = (unsigned int) strtol(optarg, NULL, 10);
862
struct argp argp = { .options = options, .parser = parse_opt,
864
.doc = "Mandos client -- Get and decrypt"
865
" passwords from mandos server" };
866
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
867
if (ret == ARGP_ERR_UNKNOWN){
868
fprintf(stderr, "Unknown error while parsing arguments\n");
869
exitcode = EXIT_FAILURE;
732
mc.priority = optarg;
739
debug = debug_int ? true : false;
874
741
pubkeyfile = combinepath(keydir, pubkeyfile);
875
742
if (pubkeyfile == NULL){
876
743
perror("combinepath");
877
exitcode = EXIT_FAILURE;
744
returncode = EXIT_FAILURE;
881
748
seckeyfile = combinepath(keydir, seckeyfile);
882
749
if (seckeyfile == NULL){
883
750
perror("combinepath");
884
exitcode = EXIT_FAILURE;
888
ret = init_gnutls_global(&mc, pubkeyfile, seckeyfile);
890
fprintf(stderr, "init_gnutls_global failed\n");
891
exitcode = EXIT_FAILURE;
894
gnutls_initalized = true;
897
/* If the interface is down, bring it up */
899
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
902
exitcode = EXIT_FAILURE;
905
strcpy(network.ifr_name, interface); /* Spurious warning */
906
ret = ioctl(sd, SIOCGIFFLAGS, &network);
908
perror("ioctl SIOCGIFFLAGS");
909
exitcode = EXIT_FAILURE;
912
if((network.ifr_flags & IFF_UP) == 0){
913
network.ifr_flags |= IFF_UP;
914
ret = ioctl(sd, SIOCSIFFLAGS, &network);
916
perror("ioctl SIOCSIFFLAGS");
917
exitcode = EXIT_FAILURE;
937
754
if_index = (AvahiIfIndex) if_nametoindex(interface);
946
763
char *address = strrchr(connect_to, ':');
947
764
if(address == NULL){
948
765
fprintf(stderr, "No colon in address\n");
949
exitcode = EXIT_FAILURE;
953
769
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
955
771
perror("Bad port number");
956
exitcode = EXIT_FAILURE;
960
775
address = connect_to;
961
776
ret = start_mandos_communication(address, port, if_index, &mc);
963
exitcode = EXIT_FAILURE;
965
exitcode = EXIT_SUCCESS;
784
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
787
returncode = EXIT_FAILURE;
790
strcpy(network.ifr_name, interface); /* Spurious warning */
791
ret = ioctl(sd, SIOCGIFFLAGS, &network);
794
perror("ioctl SIOCGIFFLAGS");
795
returncode = EXIT_FAILURE;
798
if((network.ifr_flags & IFF_UP) == 0){
799
network.ifr_flags |= IFF_UP;
800
ret = ioctl(sd, SIOCSIFFLAGS, &network);
802
perror("ioctl SIOCSIFFLAGS");
803
returncode = EXIT_FAILURE;
971
810
avahi_set_log_function(empty_log);
974
/* Initialize the pseudo-RNG for Avahi */
813
/* Initialize the psuedo-RNG */
975
814
srand((unsigned int) time(NULL));
977
/* Allocate main Avahi loop object */
978
mc.simple_poll = avahi_simple_poll_new();
979
if (mc.simple_poll == NULL) {
980
fprintf(stderr, "Avahi: Failed to create simple poll"
982
exitcode = EXIT_FAILURE;
987
AvahiServerConfig config;
988
/* Do not publish any local Zeroconf records */
989
avahi_server_config_init(&config);
990
config.publish_hinfo = 0;
991
config.publish_addresses = 0;
992
config.publish_workstation = 0;
993
config.publish_domain = 0;
995
/* Allocate a new server */
996
mc.server = avahi_server_new(avahi_simple_poll_get
997
(mc.simple_poll), &config, NULL,
1000
/* Free the Avahi configuration data */
1001
avahi_server_config_free(&config);
1004
/* Check if creating the Avahi server object succeeded */
1005
if (mc.server == NULL) {
1006
fprintf(stderr, "Failed to create Avahi server: %s\n",
816
/* Allocate main loop object */
817
if (!(mc.simple_poll = avahi_simple_poll_new())) {
818
fprintf(stderr, "Failed to create simple poll object.\n");
819
returncode = EXIT_FAILURE;
823
/* Do not publish any local records */
824
avahi_server_config_init(&config);
825
config.publish_hinfo = 0;
826
config.publish_addresses = 0;
827
config.publish_workstation = 0;
828
config.publish_domain = 0;
830
/* Allocate a new server */
831
mc.server=avahi_server_new(avahi_simple_poll_get(mc.simple_poll),
832
&config, NULL, NULL, &error);
834
/* Free the configuration data */
835
avahi_server_config_free(&config);
837
/* Check if creating the server object succeeded */
839
fprintf(stderr, "Failed to create server: %s\n",
1007
840
avahi_strerror(error));
1008
exitcode = EXIT_FAILURE;
841
returncode = EXIT_FAILURE;
1012
/* Create the Avahi service browser */
845
/* Create the service browser */
1013
846
sb = avahi_s_service_browser_new(mc.server, if_index,
1014
847
AVAHI_PROTO_INET6,
1015
848
"_mandos._tcp", NULL, 0,
1016
849
browse_callback, &mc);
1018
851
fprintf(stderr, "Failed to create service browser: %s\n",
1019
852
avahi_strerror(avahi_server_errno(mc.server)));
1020
exitcode = EXIT_FAILURE;
853
returncode = EXIT_FAILURE;
1024
857
/* Run the main loop */
1027
fprintf(stderr, "Starting Avahi loop search\n");
860
fprintf(stderr, "Starting avahi loop search\n");
1030
863
avahi_simple_poll_loop(mc.simple_poll);
1035
868
fprintf(stderr, "%s exiting\n", argv[0]);
1038
871
/* Cleanup things */
1040
873
avahi_s_service_browser_free(sb);
1042
if (mc.server != NULL)
1043
876
avahi_server_free(mc.server);
1045
if (mc.simple_poll != NULL)
1046
879
avahi_simple_poll_free(mc.simple_poll);
1047
880
free(pubkeyfile);
1048
881
free(seckeyfile);
1050
if (gnutls_initalized){
1051
gnutls_certificate_free_credentials(mc.cred);
1052
gnutls_global_deinit ();