… | |
… | |
33 | |
33 | |
34 | #include <list> |
34 | #include <list> |
35 | #include <queue> |
35 | #include <queue> |
36 | #include <utility> |
36 | #include <utility> |
37 | |
37 | |
|
|
38 | #include <openssl/opensslv.h> |
38 | #include <openssl/rand.h> |
39 | #include <openssl/rand.h> |
39 | #include <openssl/evp.h> |
40 | #include <openssl/evp.h> |
40 | #include <openssl/rsa.h> |
41 | #include <openssl/rsa.h> |
41 | #include <openssl/err.h> |
42 | #include <openssl/err.h> |
|
|
43 | |
|
|
44 | // openssl 0.9.8 compatibility |
|
|
45 | #if OPENSSL_VERSION_NUMBER < 0x10100000 |
|
|
46 | #define require101(exp) exp |
|
|
47 | #else |
|
|
48 | #define require101(exp) equire (exp) |
|
|
49 | #endif |
42 | |
50 | |
43 | #include "conf.h" |
51 | #include "conf.h" |
44 | #include "slog.h" |
52 | #include "slog.h" |
45 | #include "device.h" |
53 | #include "device.h" |
46 | #include "vpn.h" |
54 | #include "vpn.h" |
… | |
… | |
126 | kdf.extract (s, sizeof (s)); |
134 | kdf.extract (s, sizeof (s)); |
127 | kdf.extract_done (HKDF_PRF_HASH ()); |
135 | kdf.extract_done (HKDF_PRF_HASH ()); |
128 | kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info)); |
136 | kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info)); |
129 | |
137 | |
130 | HMAC_CTX_init (&hctx); |
138 | HMAC_CTX_init (&hctx); |
131 | require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0)); |
139 | require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0)); |
132 | } |
140 | } |
133 | |
141 | |
134 | { |
142 | { |
135 | u8 cipher_key[CIPHER_KEYSIZE]; |
143 | u8 cipher_key[CIPHER_KEYSIZE]; |
136 | static const unsigned char cipher_info[] = "gvpe cipher key"; |
144 | static const unsigned char cipher_info[] = "gvpe cipher key"; |
… | |
… | |
180 | } |
188 | } |
181 | |
189 | |
182 | static void |
190 | static void |
183 | auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac) |
191 | auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac) |
184 | { |
192 | { |
185 | hkdf kdf (&auth.ecdh, sizeof (auth.ecdh), AUTH_DIGEST ()); // use remote ecdh b as salt |
193 | hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt |
186 | kdf.extract (&auth.rsa, sizeof (auth.rsa)); |
194 | kdf.extract (&auth.rsa, sizeof (auth.rsa)); |
187 | kdf.extract_done (); |
195 | kdf.extract_done (); |
188 | kdf.expand (mac, sizeof mac, b, sizeof b); // use response ecdh b as info |
196 | kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info |
189 | } |
197 | } |
190 | |
198 | |
191 | void |
199 | void |
192 | connection::generate_auth_data () |
200 | connection::generate_auth_data () |
193 | { |
201 | { |
… | |
… | |
364 | void |
372 | void |
365 | hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest) |
373 | hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest) |
366 | { |
374 | { |
367 | HMAC_CTX *hctx = &ctx->hctx; |
375 | HMAC_CTX *hctx = &ctx->hctx; |
368 | |
376 | |
369 | require (HMAC_Init_ex (hctx, 0, 0, 0, 0)); |
377 | require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0)); |
370 | require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet))); |
378 | require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet))); |
371 | require (HMAC_Final (hctx, hmac_digest, 0)); |
379 | require101 (HMAC_Final (hctx, hmac_digest, 0)); |
372 | } |
380 | } |
373 | |
381 | |
374 | void |
382 | void |
375 | hmac_packet::hmac_set (crypto_ctx *ctx) |
383 | hmac_packet::hmac_set (crypto_ctx *ctx) |
376 | { |
384 | { |
… | |
… | |
693 | si = rsi; |
701 | si = rsi; |
694 | protocol = rsi.prot; |
702 | protocol = rsi.prot; |
695 | |
703 | |
696 | slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."), |
704 | slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."), |
697 | conf->nodename, (const char *)rsi, |
705 | conf->nodename, (const char *)rsi, |
698 | is_direct ? "direct" : "forwarded", |
706 | vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded", |
699 | PROTOCOL_MAJOR, prot_minor); |
707 | PROTOCOL_MAJOR, prot_minor); |
700 | |
708 | |
701 | if (::conf.script_node_up) |
709 | if (::conf.script_node_up) |
702 | { |
710 | { |
703 | run_script_cb *cb = new run_script_cb; |
711 | run_script_cb *cb = new run_script_cb; |
… | |
… | |
715 | |
723 | |
716 | // make sure rekeying timeouts are slightly asymmetric |
724 | // make sure rekeying timeouts are slightly asymmetric |
717 | ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); |
725 | ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); |
718 | rekey.start (rekey_interval, rekey_interval); |
726 | rekey.start (rekey_interval, rekey_interval); |
719 | |
727 | |
|
|
728 | hmac_error = 0.; |
|
|
729 | |
720 | keepalive.start (::conf.keepalive); |
730 | keepalive.start (::conf.keepalive); |
721 | |
731 | |
722 | // send queued packets |
732 | // send queued packets |
723 | if (ictx && octx) |
|
|
724 | { |
|
|
725 | while (tap_packet *p = (tap_packet *)data_queue.get ()) |
733 | while (tap_packet *p = (tap_packet *)data_queue.get ()) |
726 | { |
734 | { |
727 | if (p->len) send_data_packet (p); |
735 | if (p->len) send_data_packet (p); |
728 | delete p; |
736 | delete p; |
729 | } |
737 | } |
730 | |
738 | |
731 | while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) |
739 | while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) |
732 | { |
740 | { |
733 | if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); |
741 | if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); |
734 | delete p; |
742 | delete p; |
735 | } |
|
|
736 | } |
743 | } |
737 | |
744 | |
738 | vpn->connection_established (this); |
745 | vpn->connection_established (this); |
739 | } |
746 | } |
740 | |
747 | |
… | |
… | |
748 | slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); |
755 | slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); |
749 | protocol = 0; |
756 | protocol = 0; |
750 | } |
757 | } |
751 | |
758 | |
752 | si.set (conf, protocol); |
759 | si.set (conf, protocol); |
753 | |
|
|
754 | is_direct = si.valid (); |
|
|
755 | } |
760 | } |
756 | |
761 | |
757 | // ensure sockinfo is valid, forward if necessary |
762 | // ensure sockinfo is valid, forward if necessary |
758 | const sockinfo & |
763 | const sockinfo & |
759 | connection::forward_si (const sockinfo &si) const |
764 | connection::forward_si (const sockinfo &si) const |
… | |
… | |
778 | |
783 | |
779 | void |
784 | void |
780 | connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
785 | connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
781 | { |
786 | { |
782 | if (!vpn->send_vpn_packet (pkt, si, tos)) |
787 | if (!vpn->send_vpn_packet (pkt, si, tos)) |
783 | reset_connection (); |
788 | reset_connection ("packet send error"); |
784 | } |
789 | } |
785 | |
790 | |
786 | void |
791 | void |
787 | connection::send_ping (const sockinfo &si, u8 pong) |
792 | connection::send_ping (const sockinfo &si, u8 pong) |
788 | { |
793 | { |
… | |
… | |
864 | { |
869 | { |
865 | // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection |
870 | // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection |
866 | // and stop trying. should probably be handled by a per-connection expire handler. |
871 | // and stop trying. should probably be handled by a per-connection expire handler. |
867 | if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) |
872 | if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) |
868 | { |
873 | { |
869 | reset_connection (); |
874 | reset_connection ("no demand"); |
870 | return; |
875 | return; |
871 | } |
876 | } |
872 | |
877 | |
873 | last_establish_attempt = ev_now (); |
878 | last_establish_attempt = ev_now (); |
874 | |
879 | |
… | |
… | |
876 | ? (retry_cnt & 3) + 1 |
881 | ? (retry_cnt & 3) + 1 |
877 | : 1 << (retry_cnt >> 2)); |
882 | : 1 << (retry_cnt >> 2)); |
878 | |
883 | |
879 | reset_si (); |
884 | reset_si (); |
880 | |
885 | |
881 | bool slow = si.prot & PROT_SLOW; |
886 | bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power); |
882 | |
887 | |
883 | if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) |
888 | if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) |
884 | { |
889 | { |
885 | /*TODO*/ /* start the timer so we don't recurse endlessly */ |
890 | /*TODO*/ /* start the timer so we don't recurse endlessly */ |
886 | w.start (1); |
891 | w.start (1); |
… | |
… | |
896 | |
901 | |
897 | slow = slow || (dsi.prot & PROT_SLOW); |
902 | slow = slow || (dsi.prot & PROT_SLOW); |
898 | |
903 | |
899 | if (dsi.valid () && auth_rate_limiter.can (dsi)) |
904 | if (dsi.valid () && auth_rate_limiter.can (dsi)) |
900 | { |
905 | { |
901 | if (retry_cnt < 4) |
906 | // use ping after the first few retries |
|
|
907 | // TODO: on rekeys, the other node might not interpret ping correctly, |
|
|
908 | // TODO: as it will still have a valid connection |
|
|
909 | if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power)) |
902 | send_auth_request (dsi, true); |
910 | send_auth_request (dsi, true); |
903 | else |
911 | else |
904 | send_ping (dsi, 0); |
912 | send_ping (dsi, 0); |
905 | } |
913 | } |
906 | } |
914 | } |
907 | |
915 | |
908 | retry_int *= slow ? 8. : 0.9; |
916 | retry_int *= slow ? 4. : 0.9; |
909 | |
917 | |
910 | if (retry_int < conf->max_retry) |
918 | if (retry_int < conf->max_retry) |
911 | retry_cnt++; |
919 | retry_cnt++; |
912 | else |
920 | else |
913 | retry_int = conf->max_retry; |
921 | retry_int = conf->max_retry; |
… | |
… | |
915 | w.start (retry_int); |
923 | w.start (retry_int); |
916 | } |
924 | } |
917 | } |
925 | } |
918 | |
926 | |
919 | void |
927 | void |
920 | connection::reset_connection () |
928 | connection::reset_connection (const char *reason) |
921 | { |
929 | { |
922 | if (ictx && octx) |
930 | if (ictx && octx) |
923 | { |
931 | { |
924 | slog (L_INFO, _("%s(%s): connection lost"), |
932 | slog (L_INFO, _("%s(%s): connection lost (%s)"), |
925 | conf->nodename, (const char *)si); |
933 | conf->nodename, (const char *)si, reason); |
926 | |
934 | |
927 | if (::conf.script_node_down) |
935 | if (::conf.script_node_down) |
928 | { |
936 | { |
929 | run_script_cb *cb = new run_script_cb; |
937 | run_script_cb *cb = new run_script_cb; |
930 | cb->set<connection, &connection::script_node_down> (this); |
938 | cb->set<connection, &connection::script_node_down> (this); |
… | |
… | |
954 | connection::shutdown () |
962 | connection::shutdown () |
955 | { |
963 | { |
956 | if (ictx && octx) |
964 | if (ictx && octx) |
957 | send_reset (si); |
965 | send_reset (si); |
958 | |
966 | |
959 | reset_connection (); |
967 | reset_connection ("shutdown"); |
960 | } |
968 | } |
961 | |
969 | |
962 | // poor-man's rekeying |
970 | // poor-man's rekeying |
963 | inline void |
971 | inline void |
964 | connection::rekey_cb (ev::timer &w, int revents) |
972 | connection::rekey_cb (ev::timer &w, int revents) |
965 | { |
973 | { |
966 | reset_connection (); |
974 | reset_connection ("rekeying"); |
967 | establish_connection (); |
975 | establish_connection (); |
968 | } |
976 | } |
969 | |
977 | |
970 | void |
978 | void |
971 | connection::send_data_packet (tap_packet *pkt) |
979 | connection::send_data_packet (tap_packet *pkt) |
… | |
… | |
988 | |
996 | |
989 | void |
997 | void |
990 | connection::post_inject_queue () |
998 | connection::post_inject_queue () |
991 | { |
999 | { |
992 | // force a connection every now and when when packets are sent (max 1/s) |
1000 | // force a connection every now and when when packets are sent (max 1/s) |
993 | if (ev_now () - last_establish_attempt >= 0.95) // arbitrary |
1001 | if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary |
994 | establish_connection.stop (); |
1002 | establish_connection.stop (); |
995 | |
1003 | |
996 | establish_connection (); |
1004 | establish_connection (); |
997 | } |
1005 | } |
998 | |
1006 | |
… | |
… | |
1058 | // about our desire for communication. |
1066 | // about our desire for communication. |
1059 | establish_connection (); |
1067 | establish_connection (); |
1060 | break; |
1068 | break; |
1061 | |
1069 | |
1062 | case vpn_packet::PT_RESET: |
1070 | case vpn_packet::PT_RESET: |
|
|
1071 | slog (L_TRACE, "%s >> PT_RESET", conf->nodename); |
|
|
1072 | |
|
|
1073 | if (ictx && octx) |
1063 | { |
1074 | { |
1064 | reset_connection (); |
1075 | reset_connection ("remote reset"); |
1065 | |
1076 | |
1066 | config_packet *p = (config_packet *) pkt; |
1077 | config_packet *p = (config_packet *) pkt; |
1067 | |
1078 | |
1068 | if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS) |
1079 | if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS) |
1069 | establish_connection (); |
1080 | establish_connection (); |
1070 | } |
1081 | } |
|
|
1082 | |
1071 | break; |
1083 | break; |
1072 | |
1084 | |
1073 | case vpn_packet::PT_AUTH_REQ: |
1085 | case vpn_packet::PT_AUTH_REQ: |
1074 | if (auth_rate_limiter.can (rsi)) |
1086 | if (auth_rate_limiter.can (rsi)) |
1075 | { |
1087 | { |
… | |
… | |
1090 | slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), |
1102 | slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), |
1091 | conf->nodename, (const char *)rsi, |
1103 | conf->nodename, (const char *)rsi, |
1092 | PROTOCOL_MINOR, conf->nodename, p->prot_minor); |
1104 | PROTOCOL_MINOR, conf->nodename, p->prot_minor); |
1093 | |
1105 | |
1094 | if (p->initiate) |
1106 | if (p->initiate) |
|
|
1107 | { |
1095 | send_auth_request (rsi, false); |
1108 | send_auth_request (rsi, false); |
|
|
1109 | |
|
|
1110 | if (ictx && octx) |
|
|
1111 | reset_connection ("reconnect"); |
|
|
1112 | } |
1096 | |
1113 | |
1097 | auth_data auth; |
1114 | auth_data auth; |
1098 | |
1115 | |
1099 | if (!auth_decrypt (::conf.rsa_key, p->encr, auth)) |
1116 | if (!auth_decrypt (::conf.rsa_key, p->encr, auth)) |
1100 | { |
1117 | { |
… | |
… | |
1146 | memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b); |
1163 | memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b); |
1147 | |
1164 | |
1148 | have_snd_auth = true; |
1165 | have_snd_auth = true; |
1149 | connection_established (rsi); |
1166 | connection_established (rsi); |
1150 | } |
1167 | } |
1151 | |
|
|
1152 | break; |
|
|
1153 | } |
1168 | } |
1154 | |
|
|
1155 | send_reset (rsi); |
|
|
1156 | break; |
1169 | break; |
1157 | |
1170 | |
1158 | case vpn_packet::PT_DATA_COMPRESSED: |
1171 | case vpn_packet::PT_DATA_COMPRESSED: |
1159 | #if !ENABLE_COMPRESSION |
1172 | #if !ENABLE_COMPRESSION |
1160 | send_reset (rsi); |
1173 | send_reset (rsi); |
… | |
… | |
1166 | if (ictx && octx) |
1179 | if (ictx && octx) |
1167 | { |
1180 | { |
1168 | vpndata_packet *p = (vpndata_packet *)pkt; |
1181 | vpndata_packet *p = (vpndata_packet *)pkt; |
1169 | |
1182 | |
1170 | if (!p->hmac_chk (ictx)) |
1183 | if (!p->hmac_chk (ictx)) |
|
|
1184 | { |
|
|
1185 | // rekeying often creates temporary hmac auth floods |
|
|
1186 | // we assume they don't take longer than a few seconds normally, |
|
|
1187 | // and suppress messages and resets during that time. |
|
|
1188 | //TODO: should be done per source address |
|
|
1189 | if (!hmac_error) |
|
|
1190 | { |
|
|
1191 | hmac_error = ev_now () + 3; |
|
|
1192 | break; |
|
|
1193 | } |
|
|
1194 | else if (hmac_error >= ev_now ()) |
|
|
1195 | break; // silently suppress |
|
|
1196 | else |
|
|
1197 | { |
1171 | slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" |
1198 | slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" |
1172 | "could be an attack, or just corruption or a synchronization error."), |
1199 | "could be an attack, or just corruption or a synchronization error."), |
1173 | conf->nodename, (const char *)rsi); |
1200 | conf->nodename, (const char *)rsi); |
|
|
1201 | // reset |
|
|
1202 | } |
|
|
1203 | } |
1174 | else |
1204 | else |
1175 | { |
1205 | { |
1176 | u32 seqno; |
1206 | u32 seqno; |
1177 | tap_packet *d = p->unpack (this, seqno); |
1207 | tap_packet *d = p->unpack (this, seqno); |
1178 | int seqclass = iseqno.seqno_classify (seqno); |
1208 | int seqclass = iseqno.seqno_classify (seqno); |
|
|
1209 | |
|
|
1210 | hmac_error = 0; |
1179 | |
1211 | |
1180 | if (seqclass == 0) // ok |
1212 | if (seqclass == 0) // ok |
1181 | { |
1213 | { |
1182 | vpn->tap->send (d); |
1214 | vpn->tap->send (d); |
1183 | |
1215 | |
… | |
… | |
1310 | |
1342 | |
1311 | if (when >= 0) |
1343 | if (when >= 0) |
1312 | w.start (when); |
1344 | w.start (when); |
1313 | else if (when < -15) |
1345 | else if (when < -15) |
1314 | { |
1346 | { |
1315 | reset_connection (); |
1347 | reset_connection ("keepalive overdue"); |
1316 | establish_connection (); |
1348 | establish_connection (); |
1317 | } |
1349 | } |
1318 | else if (conf->connectmode != conf_node::C_ONDEMAND |
1350 | else if (conf->connectmode != conf_node::C_ONDEMAND |
1319 | || THISNODE->connectmode != conf_node::C_ONDEMAND) |
1351 | || THISNODE->connectmode != conf_node::C_ONDEMAND) |
1320 | { |
1352 | { |
… | |
… | |
1324 | else if (when >= -10) |
1356 | else if (when >= -10) |
1325 | // hold ondemand connections implicitly a few seconds longer |
1357 | // hold ondemand connections implicitly a few seconds longer |
1326 | // should delete octx, though, or something like that ;) |
1358 | // should delete octx, though, or something like that ;) |
1327 | w.start (when + 10); |
1359 | w.start (when + 10); |
1328 | else |
1360 | else |
1329 | reset_connection (); |
1361 | reset_connection ("keepalive timeout"); |
1330 | } |
1362 | } |
1331 | |
1363 | |
1332 | void |
1364 | void |
1333 | connection::send_connect_request (int id) |
1365 | connection::send_connect_request (int id) |
1334 | { |
1366 | { |
… | |
… | |
1434 | |
1466 | |
1435 | // queue a dummy packet to force an initial connection attempt |
1467 | // queue a dummy packet to force an initial connection attempt |
1436 | if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) |
1468 | if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) |
1437 | vpn_queue.put (new net_packet); |
1469 | vpn_queue.put (new net_packet); |
1438 | |
1470 | |
1439 | reset_connection (); |
1471 | reset_connection ("startup"); |
1440 | } |
1472 | } |
1441 | |
1473 | |
1442 | connection::~connection () |
1474 | connection::~connection () |
1443 | { |
1475 | { |
1444 | shutdown (); |
1476 | shutdown (); |