--- gvpe/src/connection.C 2008/08/08 16:48:00 1.72 +++ gvpe/src/connection.C 2013/07/18 13:35:16 1.102 @@ -1,6 +1,6 @@ /* connection.C -- manage a single connection - Copyright (C) 2003-2008 Marc Lehmann + Copyright (C) 2003-2008,2010,2011,2013 Marc Lehmann This file is part of GVPE. @@ -45,14 +45,12 @@ #include "device.h" #include "vpn.h" #include "connection.h" +#include "hkdf.h" #include "netcompat.h" -#if !HAVE_RAND_PSEUDO_BYTES -# define RAND_pseudo_bytes RAND_bytes -#endif - -#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic +#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic +#define MAGIC "HUHN\xbd\xc6\xdb\x82" // 8 bytes of magic//D #define ULTRA_FAST 1 #define HLOG 15 @@ -65,26 +63,29 @@ static std::queue< std::pair > rs_queue; static ev::child rs_child_ev; -void // c++ requires external linkage here, apparently :( -rs_child_cb (ev::child &w, int revents) +namespace { - w.stop (); + void // c++ requires external linkage here, apparently :( + rs_child_cb (ev::child &w, int revents) + { + w.stop (); - if (rs_queue.empty ()) - return; + if (rs_queue.empty ()) + return; - pid_t pid = run_script (*rs_queue.front ().first, false); - if (pid) - { - w.set (pid); - w.start (); - } - else - slog (L_WARN, rs_queue.front ().second); + pid_t pid = run_script (*rs_queue.front ().first, false); + if (pid) + { + w.set (pid); + w.start (); + } + else + slog (L_WARN, rs_queue.front ().second); - delete rs_queue.front ().first; - rs_queue.pop (); -} + delete rs_queue.front ().first; + rs_queue.pop (); + } +}; // despite the fancy name, this is quite a hack static void @@ -106,16 +107,43 @@ EVP_CIPHER_CTX cctx; HMAC_CTX hctx; - crypto_ctx (const rsachallenge &challenge, int enc); + crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc); ~crypto_ctx (); }; -crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) +crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc) { - EVP_CIPHER_CTX_init (&cctx); - require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); - HMAC_CTX_init (&hctx); - HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0); + ecdh_key s; + + curve25519_combine (a, b, s); + + { + u8 mac_key[MAC_KEYSIZE]; + static const unsigned char mac_info[] = "gvpe mac key"; + + hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); + kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key)); + kdf.extract (s, sizeof (s)); + kdf.extract_done (HKDF_PRF_HASH ()); + kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info)); + + HMAC_CTX_init (&hctx); + require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0)); + } + + { + u8 cipher_key[CIPHER_KEYSIZE]; + static const unsigned char cipher_info[] = "gvpe cipher key"; + + hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); + kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key)); + kdf.extract (s, sizeof (s)); + kdf.extract_done (HKDF_PRF_HASH ()); + kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info)); + + EVP_CIPHER_CTX_init (&cctx); + require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc)); + } } crypto_ctx::~crypto_ctx () @@ -124,86 +152,61 @@ HMAC_CTX_cleanup (&hctx); } -static void -rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) +static inline void +auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr) { - EVP_MD_CTX ctx; + if (RSA_public_encrypt (sizeof (auth.rsa), + (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa, + key, RSA_PKCS1_OAEP_PADDING) < 0) + fatal ("RSA_public_encrypt error"); - EVP_MD_CTX_init (&ctx); - require (EVP_DigestInit (&ctx, RSA_HASH)); - require (EVP_DigestUpdate(&ctx, &chg, sizeof chg)); - require (EVP_DigestUpdate(&ctx, &id, sizeof id)); - require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0)); - EVP_MD_CTX_cleanup (&ctx); + memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh)); } -struct rsa_entry +static inline bool +auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth) { - tstamp expire; - rsaid id; - rsachallenge chg; -}; - -struct rsa_cache : list -{ - inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner; - - bool find (const rsaid &id, rsachallenge &chg) - { - for (iterator i = begin (); i != end (); ++i) - { - if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) - { - memcpy (&chg, &i->chg, sizeof chg); - - erase (i); - return true; - } - } - - if (!cleaner.is_active ()) - cleaner.again (); + u8 rsa_decrypt[RSA_KEYLEN]; - return false; - } - - void gen (rsaid &id, rsachallenge &chg) - { - rsa_entry e; - - RAND_bytes ((unsigned char *)&id, sizeof id); - RAND_bytes ((unsigned char *)&chg, sizeof chg); - - e.expire = ev_now () + RSA_TTL; - e.id = id; - memcpy (&e.chg, &chg, sizeof chg); + if (RSA_private_decrypt (sizeof (encr.rsa), + (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt, + key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa)) + return 0; - push_back (e); + memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa)); + memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh)); - if (!cleaner.is_active ()) - cleaner.again (); - } + return 1; +} - rsa_cache () - { - cleaner.set (this); - cleaner.set (RSA_TTL, RSA_TTL); - } +static void +auth_hash (const auth_data &auth, auth_mac &mac) +{ + HMAC_CTX ctx; -} rsa_cache; + HMAC_CTX_init (&ctx); + require (HMAC_Init_ex (&ctx, auth.rsa.auth_key, sizeof (auth.rsa.auth_key), AUTH_DIGEST (), 0)); + require (HMAC_Update (&ctx, (const unsigned char *)&auth, sizeof auth)); + require (HMAC_Final (&ctx, (unsigned char *)&mac, 0)); + HMAC_CTX_cleanup (&ctx); +} -void rsa_cache::cleaner_cb (ev::timer &w, int revents) +void +connection::generate_auth_data () { - if (empty ()) - w.stop (); - else + if (auth_expire < ev_now ()) { - for (iterator i = begin (); i != end (); ) - if (i->expire <= ev_now ()) - i = erase (i); - else - ++i; + // request data + rand_fill (snd_auth.rsa); + curve25519_generate (snd_ecdh_a, snd_auth.ecdh); + auth_hash (snd_auth, snd_auth_mac); + + // eventual response data + curve25519_generate (rcv_ecdh_a, rcv_ecdh_b); } + + // every use prolongs the expiry + auth_expire = ev_now () + AUTH_TTL; } ////////////////////////////////////////////////////////////////////////////// @@ -227,7 +230,8 @@ delete [] queue; } -void pkt_queue::expire_cb (ev::timer &w, int revents) +void +pkt_queue::expire_cb (ev::timer &w, int revents) { ev_tstamp expire = ev_now () - max_ttl; @@ -248,7 +252,8 @@ } } -void pkt_queue::put (net_packet *p) +void +pkt_queue::put (net_packet *p) { ev_tstamp now = ev_now (); @@ -267,7 +272,8 @@ i = ni; } -net_packet *pkt_queue::get () +net_packet * +pkt_queue::get () { if (empty ()) return 0; @@ -301,9 +307,10 @@ bool can (u32 host); }; -net_rate_limiter auth_rate_limiter, reset_rate_limiter; +static net_rate_limiter auth_rate_limiter, reset_rate_limiter; -bool net_rate_limiter::can (u32 host) +bool +net_rate_limiter::can (u32 host) { iterator i; @@ -360,16 +367,17 @@ unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; -void hmac_packet::hmac_gen (crypto_ctx *ctx) +void +hmac_packet::hmac_gen (crypto_ctx *ctx) { unsigned int xlen; HMAC_CTX *hctx = &ctx->hctx; - HMAC_Init_ex (hctx, 0, 0, 0, 0); - HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), - len - sizeof (hmac_packet)); - HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen); + require (HMAC_Init_ex (hctx, 0, 0, 0, 0)); + require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), + len - sizeof (hmac_packet))); + require (HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen)); } void @@ -388,7 +396,8 @@ return !memcmp (hmac, hmac_digest, HMACLENGTH); } -void vpn_packet::set_hdr (ptype type_, unsigned int dst) +void +vpn_packet::set_hdr (ptype type_, unsigned int dst) { type = type_; @@ -403,18 +412,18 @@ #define DATAHDR (sizeof (u32) + RAND_SIZE) struct vpndata_packet : vpn_packet - { - u8 data[MAXVPNDATA + DATAHDR]; // seqno +{ + u8 data[MAXVPNDATA + DATAHDR]; // seqno - void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno); - tap_packet *unpack (connection *conn, u32 &seqno); -private: + void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno); + tap_packet *unpack (connection *conn, u32 &seqno); - const u32 data_hdr_size () const - { - return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; - } - }; +private: + const u32 data_hdr_size () const + { + return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; + } +}; void vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) @@ -426,7 +435,7 @@ #if ENABLE_COMPRESSION u8 cdata[MAX_MTU]; - if (conn->features & ENABLE_COMPRESSION) + if (conn->features & FEATURE_COMPRESSION) { u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); @@ -442,7 +451,7 @@ } #endif - require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); + require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1)); struct { #if RAND_SIZE @@ -453,7 +462,9 @@ datahdr.seqno = ntohl (seqno); #if RAND_SIZE - RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); + // NB: a constant (per session) random prefix + // is likely enough, but we don't take any chances. + conn->oiv.get (datahdr.rnd, RAND_SIZE); #endif require (EVP_EncryptUpdate (cctx, @@ -485,7 +496,7 @@ u8 *d; u32 l = len - data_hdr_size (); - require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); + require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0)); #if ENABLE_COMPRESSION u8 cdata[MAX_MTU]; @@ -494,9 +505,15 @@ d = cdata; else #endif - d = &(*p)[6 + 6 - DATAHDR]; + d = &(*p)[6 + 6] - DATAHDR; + + // we play do evil games with the struct layout atm. + // pending better solutions, we at least do some verification. + // this is fine, as we left ISO territory long ago. + require (DATAHDR <= 16); + require ((u8 *)(&p->len + 1) == &(*p)[0]); - /* this overwrites part of the src mac, but we fix that later */ + // this can overwrite the len/dst/src fields require (EVP_DecryptUpdate (cctx, d, &outl2, (unsigned char *)&data, len - data_hdr_size ())); @@ -537,12 +554,9 @@ struct config_packet : vpn_packet { - // actually, hmaclen cannot be checked because the hmac - // field comes before this data, so peers with other - // hmacs simply will not work. - u8 prot_major, prot_minor, randsize, hmaclen; - u8 flags, challengelen, features, pad3; - u32 cipher_nid, digest_nid, hmac_nid; + u8 prot_major, prot_minor, randsize; + u8 flags, features, pad6, pad7, pad8; + u32 cipher_nid, mac_nid, auth_nid; void setup (ptype type, int dst); bool chk_config () const; @@ -563,59 +577,54 @@ } }; -void config_packet::setup (ptype type, int dst) +void +config_packet::setup (ptype type, int dst) { prot_major = PROTOCOL_MAJOR; prot_minor = PROTOCOL_MINOR; randsize = RAND_SIZE; - hmaclen = HMACLENGTH; flags = 0; - challengelen = sizeof (rsachallenge); features = get_features (); - cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); - digest_nid = htonl (EVP_MD_type (RSA_HASH)); - hmac_nid = htonl (EVP_MD_type (DIGEST)); + cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ())); + mac_nid = htonl (EVP_MD_type (MAC_DIGEST ())); + auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ())); len = sizeof (*this) - sizeof (net_packet); set_hdr (type, dst); } -bool config_packet::chk_config () const +bool +config_packet::chk_config () const { if (prot_major != PROTOCOL_MAJOR) slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); else if (randsize != RAND_SIZE) slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); - else if (hmaclen != HMACLENGTH) - slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH); - else if (challengelen != sizeof (rsachallenge)) - slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge)); - else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) - slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); - else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) - slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH)); - else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) - slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); + else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ()))) + slog (L_WARN, _("cipher algo mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ())); + else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ()))) + slog (L_WARN, _("mac algo mismatch (remote %x <=> local %x)"), ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ())); + else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ()))) + slog (L_WARN, _("auth algo mismatch (remote %x <=> local %x)"), ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ())); else return true; return false; } -struct auth_req_packet : config_packet +struct auth_req_packet : config_packet // UNPROTECTED { char magic[8]; u8 initiate; // false if this is just an automatic reply u8 protocols; // supported protocols (will be patched on forward) u8 pad2, pad3; - rsaid id; - rsaencrdata encr; + auth_encr encr; auth_req_packet (int dst, bool initiate_, u8 protocols_) { config_packet::setup (PT_AUTH_REQ, dst); - strncpy (magic, MAGIC, 8); + memcpy (magic, MAGIC, 8); initiate = !!initiate_; protocols = protocols_; @@ -623,12 +632,9 @@ } }; -struct auth_res_packet : config_packet +struct auth_res_packet : config_packet // UNPROTECTED { - rsaid id; - u8 pad1, pad2, pad3; - u8 response_len; // encrypted length - rsaresponse response; + auth_response response; auth_res_packet (int dst) { @@ -672,61 +678,73 @@ ///////////////////////////////////////////////////////////////////////////// void -connection::connection_established () +connection::connection_established (const sockinfo &rsi) { - slog (L_TRACE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); + if (!have_snd_auth || !have_rcv_auth) + return; + + si = rsi; + protocol = rsi.prot; + + slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."), + conf->nodename, (const char *)rsi, + is_direct ? "direct" : "forwarded", + PROTOCOL_MAJOR, prot_minor); + + if (::conf.script_node_up) + { + run_script_cb *cb = new run_script_cb; + cb->set (this); + run_script_queued (cb, _("node-up command execution failed, continuing.")); + } + + delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0); + iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff); + delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1); + oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff; + + oiv.reset (); + + // make sure rekeying timeouts are slightly asymmetric + ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); + rekey.start (rekey_interval, rekey_interval); + + keepalive.start (::conf.keepalive); + + // send queued packets if (ictx && octx) { - // make sure rekeying timeouts are slightly asymmetric - ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); - rekey.start (rekey_interval, rekey_interval); - keepalive.start (::conf.keepalive); - - // send queued packets - if (ictx && octx) + while (tap_packet *p = (tap_packet *)data_queue.get ()) { - while (tap_packet *p = (tap_packet *)data_queue.get ()) - { - if (p->len) send_data_packet (p); - delete p; - } + if (p->len) send_data_packet (p); + delete p; + } - while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) - { - if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); - delete p; - } + while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) + { + if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); + delete p; } } - else - { - retry_cnt = 0; - establish_connection.start (5); - keepalive.stop (); - rekey.stop (); - } + + vpn->connection_established (this); } void connection::reset_si () { - protocol = best_protocol (THISNODE->protocols & conf->protocols); - - // mask out endpoints we can't connect to - if (!conf->udp_port) protocol &= ~PROT_UDPv4; - if (!conf->tcp_port) protocol &= ~PROT_TCPv4; - if (!conf->dns_port) protocol &= ~PROT_DNSv4; - - if (protocol - && (!conf->can_direct (THISNODE) - || !THISNODE->can_direct (conf))) + if (vpn->can_direct (THISNODE, conf)) + protocol = best_protocol (THISNODE->protocols & conf->connectable_protocols ()); + else { - slog (L_DEBUG, _("%s: direct connection denied"), conf->nodename); + slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); protocol = 0; } si.set (conf, protocol); + + is_direct = si.valid (); } // ensure sockinfo is valid, forward if necessary @@ -735,16 +753,16 @@ { if (!si.valid ()) { - connection *r = vpn->find_router (); + connection *r = vpn->find_router_for (this); if (r) { - slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s (%s)"), - conf->nodename, r->conf->nodename, (const char *)r->si); + slog (L_DEBUG, _("%s: no common protocol, trying to route through %s."), + conf->nodename, r->conf->nodename); return r->si; } else - slog (L_DEBUG, _("%s: node unreachable, no common protocol, no router"), + slog (L_DEBUG, _("%s: node unreachable, no common protocol or no router available."), conf->nodename); } @@ -764,6 +782,8 @@ ping_packet *pkt = new ping_packet; pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); + + slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); send_vpn_packet (pkt, si, IPTOS_LOWDELAY); delete pkt; @@ -788,30 +808,24 @@ { auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); - rsachallenge chg; - rsa_cache.gen (pkt->id, chg); - rsa_encrypt (conf->rsa_key, chg, pkt->encr); - - slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); + generate_auth_data (); + auth_encrypt (conf->rsa_key, snd_auth, pkt->encr); + slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly delete pkt; } void -connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) +connection::send_auth_response (const sockinfo &si) { auth_res_packet *pkt = new auth_res_packet (conf->id); - pkt->id = id; - - rsa_hash (id, chg, pkt->response); - - pkt->hmac_set (octx); - - slog (L_TRACE, ">>%d PT_AUTH_RES [%s]", conf->id, (const char *)si); + auth_hash (rcv_auth, pkt->response.mac); + memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof (rcv_ecdh_b)); + slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly delete pkt; @@ -820,8 +834,9 @@ void connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) { - slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)", - conf->id, rid, (const char *)rsi); + slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename, + vpn->conns[rid - 1]->conf->nodename, (const char *)rsi, + conf->protocols); connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); @@ -834,7 +849,7 @@ inline void connection::establish_connection_cb (ev::timer &w, int revents) { - if (!ictx + if (!(ictx && octx) && conf != THISNODE && connectmode != conf_node::C_NEVER && connectmode != conf_node::C_DISABLED @@ -858,16 +873,17 @@ bool slow = si.prot & PROT_SLOW; - if (si.prot && !si.host) + if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) { - slog (L_TRACE, _("%s: connection request (indirect)"), conf->nodename); /*TODO*/ /* start the timer so we don't recurse endlessly */ w.start (1); - vpn->send_connect_request (conf->id); + vpn->send_connect_request (this); } else { - slog (L_TRACE, _("%s: connection request (direct)"), conf->nodename, !!ictx, !!octx); + if (si.valid ()) + slog (L_DEBUG, _("%s: sending direct connection request to %s."), + conf->nodename, (const char *)si); const sockinfo &dsi = forward_si (si); @@ -911,13 +927,15 @@ delete ictx; ictx = 0; delete octx; octx = 0; -#if ENABLE_DNS - dnsv4_reset_connection (); -#endif si.host = 0; - last_activity = 0; + have_snd_auth = false; + have_rcv_auth = false; + auth_expire = 0.; + + last_activity = 0.; + //last_si_change = 0.; retry_cnt = 0; rekey.stop (); @@ -934,6 +952,7 @@ reset_connection (); } +// poor-man's rekeying inline void connection::rekey_cb (ev::timer &w, int revents) { @@ -982,7 +1001,8 @@ } } -void connection::inject_vpn_packet (vpn_packet *pkt, int tos) +void +connection::inject_vpn_packet (vpn_packet *pkt, int tos) { if (ictx && octx) send_vpn_packet (pkt, si, tos); @@ -998,8 +1018,8 @@ { last_activity = ev_now (); - slog (L_NOISE, "<<%d received packet type %d from %d to %d", - conf->id, pkt->typ (), pkt->src (), pkt->dst ()); + slog (L_NOISE, "%s >> received packet type %d from %d to %d.", + conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); if (connectmode == conf_node::C_DISABLED) return; @@ -1007,6 +1027,8 @@ switch (pkt->typ ()) { case vpn_packet::PT_PING: + slog (L_TRACE, "%s >> PT_PING", conf->nodename); + // we send pings instead of auth packets after some retries, // so reset the retry counter and establish a connection // when we receive a ping. @@ -1016,11 +1038,18 @@ send_auth_request (rsi, true); } else + // we would love to change the socket address here, but ping's aren't + // authenticated, so we best ignore it. send_ping (rsi, 1); // pong break; case vpn_packet::PT_PONG: + slog (L_TRACE, "%s >> PT_PONG", conf->nodename); + + // a PONG might mean that the other side doesn't really know + // about our desire for communication. + establish_connection (); break; case vpn_packet::PT_RESET: @@ -1031,7 +1060,7 @@ if (!p->chk_config ()) { - slog (L_WARN, _("%s(%s): protocol mismatch, disabling node"), + slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."), conf->nodename, (const char *)rsi); connectmode = conf_node::C_DISABLED; } @@ -1043,11 +1072,13 @@ case vpn_packet::PT_AUTH_REQ: if (auth_rate_limiter.can (rsi)) { - auth_req_packet *p = (auth_req_packet *) pkt; + auth_req_packet *p = (auth_req_packet *)pkt; - slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate); + slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)", + conf->nodename, p->initiate ? "initiate" : "reply", + p->protocols, p->features); - if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) + if (p->chk_config () && !memcmp (p->magic, MAGIC, 8)) { if (p->prot_minor != PROTOCOL_MINOR) slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), @@ -1057,33 +1088,35 @@ if (p->initiate) send_auth_request (rsi, false); - rsachallenge k; + auth_data auth; - if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) + if (!auth_decrypt (::conf.rsa_key, p->encr, auth)) { slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); - break; } else { - delete octx; + bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth); - octx = new crypto_ctx (k, 1); - oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; + rcv_auth = auth; + have_rcv_auth = true; - conf->protocols = p->protocols; - features = p->features & config_packet::get_features (); + send_auth_response (rsi); - send_auth_response (rsi, p->id, k); - - connection_established (); + if (chg) + { + conf->protocols = p->protocols; + features = p->features & config_packet::get_features (); - break; + connection_established (rsi); + } } + + break; } else - slog (L_WARN, _("%s(%s): protocol mismatch"), + slog (L_WARN, _("%s(%s): protocol mismatch."), conf->nodename, (const char *)rsi); send_reset (rsi); @@ -1093,75 +1126,32 @@ case vpn_packet::PT_AUTH_RES: { - auth_res_packet *p = (auth_res_packet *) pkt; + auth_res_packet *p = (auth_res_packet *)pkt; - slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id); + slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); if (p->chk_config ()) { - if (p->prot_minor != PROTOCOL_MINOR) - slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), - conf->nodename, (const char *)rsi, - PROTOCOL_MINOR, conf->nodename, p->prot_minor); - - rsachallenge chg; - - if (!rsa_cache.find (p->id, chg)) + if (memcmp (&p->response.mac, snd_auth_mac, sizeof (snd_auth_mac))) { - slog (L_ERR, _("%s(%s): unrequested auth response ignored"), + slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."), conf->nodename, (const char *)rsi); - break; } - else + else if (!have_snd_auth) { - crypto_ctx *cctx = new crypto_ctx (chg, 0); + if (p->prot_minor != PROTOCOL_MINOR) + slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), + conf->nodename, (const char *)rsi, + PROTOCOL_MINOR, conf->nodename, p->prot_minor); - if (!p->hmac_chk (cctx)) - { - slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" - "could be an attack, or just corruption or a synchronization error"), - conf->nodename, (const char *)rsi); - break; - } - else - { - rsaresponse h; - - rsa_hash (p->id, chg, h); - - if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h)) - { - prot_minor = p->prot_minor; - - delete ictx; ictx = cctx; - - iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid - - si = rsi; - protocol = rsi.prot; - - connection_established (); - - slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"), - conf->nodename, (const char *)rsi, - p->prot_major, p->prot_minor); - - if (::conf.script_node_up) - { - run_script_cb *cb = new run_script_cb; - cb->set (this); - run_script_queued (cb, _("node-up command execution failed, continuing.")); - } - - break; - } - else - slog (L_ERR, _("%s(%s): sent and received challenge do not match"), - conf->nodename, (const char *)rsi); - } + prot_minor = p->prot_minor; + memcpy (snd_ecdh_b, p->response.ecdh, sizeof (snd_ecdh_b)); - delete cctx; + have_snd_auth = true; + connection_established (rsi); } + + break; } } @@ -1182,26 +1172,53 @@ if (!p->hmac_chk (ictx)) slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" - "could be an attack, or just corruption or a synchronization error"), + "could be an attack, or just corruption or a synchronization error."), conf->nodename, (const char *)rsi); else { u32 seqno; tap_packet *d = p->unpack (this, seqno); + int seqclass = iseqno.seqno_classify (seqno); - if (iseqno.recv_ok (seqno)) + if (seqclass == 0) // ok { vpn->tap->send (d); if (si != rsi) { // fast re-sync on source address changes, useful especially for tcp/ip - si = rsi; - - slog (L_INFO, _("%s(%s): socket address changed to %s"), - conf->nodename, (const char *)si, (const char *)rsi); + //if (last_si_change < ev_now () + 5.) + // { + slog (L_INFO, _("%s(%s): changing socket address to %s."), + conf->nodename, (const char *)si, (const char *)rsi); + + si = rsi; + + if (::conf.script_node_change) + { + run_script_cb *cb = new run_script_cb; + cb->set (this); + run_script_queued (cb, _("node-change command execution failed, continuing.")); + } + + // } + //else + // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."), + // conf->nodename, (const char *)si, (const char *)rsi); } } + else if (seqclass == 1) // far history + slog (L_ERR, _("received very old packet (received %08lx, expected %08lx). " + "possible replay attack, or just packet duplication/delay, ignoring."), seqno, iseqno.seq + 1); + else if (seqclass == 2) // in-window duplicate, happens often on wireless + slog (L_DEBUG, _("received recent duplicated packet (received %08lx, expected %08lx). " + "possible replay attack, or just packet duplication, ignoring."), seqno, iseqno.seq + 1); + else if (seqclass == 3) // reset + { + slog (L_ERR, _("received out-of-sync (far future) packet (received %08lx, expected %08lx). " + "probably just massive packet loss, sending reset."), seqno, iseqno.seq + 1); + send_reset (rsi); + } delete d; break; @@ -1214,15 +1231,17 @@ case vpn_packet::PT_CONNECT_REQ: if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) { - connect_req_packet *p = (connect_req_packet *) pkt; + connect_req_packet *p = (connect_req_packet *)pkt; if (p->id > 0 && p->id <= vpn->conns.size ()) { connection *c = vpn->conns[p->id - 1]; conf->protocols = p->protocols; - slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]", - conf->id, p->id, c->ictx && c->octx); + slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]", + conf->nodename, vpn->conns[p->id - 1]->conf->nodename, + p->protocols, + c->ictx && c->octx); if (c->ictx && c->octx) { @@ -1255,13 +1274,23 @@ protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); p->si.upgrade_protocol (protocol, c->conf); - slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", - conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); + slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]", + conf->nodename, + vpn->conns[p->id - 1]->conf->nodename, + (const char *)p->si, + p->protocols, + protocol, + p->si.supported_protocols (c->conf), + !c->ictx && !c->octx); const sockinfo &dsi = forward_si (p->si); if (dsi.valid ()) c->send_auth_request (dsi, true); + else + slog (L_INFO, "connect info for %s received (%s), but still unable to contact.", + vpn->conns[p->id - 1]->conf->nodename, + (const char *)p->si); } else slog (L_WARN, @@ -1280,57 +1309,65 @@ inline void connection::keepalive_cb (ev::timer &w, int revents) { - if (ev_now () >= last_activity + ::conf.keepalive + 30) + ev_tstamp when = last_activity + ::conf.keepalive - ev::now (); + + if (when >= 0) + w.start (when); + else if (when < -15) { reset_connection (); establish_connection (); } - else if (ev_now () < last_activity + ::conf.keepalive) - w.start (last_activity + ::conf.keepalive - ev::now ()); else if (conf->connectmode != conf_node::C_ONDEMAND || THISNODE->connectmode != conf_node::C_ONDEMAND) { + w.start (3); send_ping (si); - w.start (5); } - else if (ev_now () < last_activity + ::conf.keepalive + 10) + else if (when >= -10) // hold ondemand connections implicitly a few seconds longer // should delete octx, though, or something like that ;) - w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); + w.start (when + 10); else reset_connection (); } -void connection::send_connect_request (int id) +void +connection::send_connect_request (int id) { - connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); + connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols); - slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); + slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)", + conf->nodename, vpn->conns[id - 1]->conf->nodename, + THISNODE->protocols); p->hmac_set (octx); send_vpn_packet (p, si); delete p; } -void connection::script_init_env (const char *ext) +void +connection::script_init_env (const char *ext) { char *env; asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); - asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); + asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, - conf->id & 0xff); putenv (env); + conf->id & 0xff); putenv (env); } -void connection::script_init_connect_env () +void +connection::script_init_connect_env () { vpn->script_init_env (); char *env; - asprintf (&env, "DESTID=%d", conf->id); putenv (env); - asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); - asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); - asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); + asprintf (&env, "DESTID=%d", conf->id); putenv (env); + asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env); + asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); + asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); + asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); } inline const char * @@ -1350,6 +1387,22 @@ } inline const char * +connection::script_node_change () +{ + script_init_connect_env (); + + putenv ((char *)"STATE=change"); + + char *filename; + asprintf (&filename, + "%s/%s", + confbase, + ::conf.script_node_change ? ::conf.script_node_change : "node-change"); + + return filename; +} + +inline const char * connection::script_node_down () { script_init_connect_env (); @@ -1380,9 +1433,6 @@ last_establish_attempt = 0.; octx = ictx = 0; - if (!conf->protocols) // make sure some protocol is enabled - conf->protocols = PROT_UDPv4; - connectmode = conf->connectmode; // queue a dummy packet to force an initial connection attempt @@ -1397,7 +1447,8 @@ shutdown (); } -void connection_init () +void +connection_init () { auth_rate_limiter.clear (); reset_rate_limiter.clear ();