[ViewVC] Diff of: cvs/gvpe/src/connection.C

Comparing gvpe/src/connection.C (file contents):
Revision 1.104 by root, Fri Jul 19 18:18:27 2013 UTC vs.
Revision 1.112 by root, Fri Sep 12 10:40:43 2014 UTC

 #include <list>
 #include <queue>
 #include <utility>
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 #include <openssl/evp.h>
 #include <openssl/rsa.h>
 #include <openssl/err.h>
+// openssl 0.9.8 compatibility
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+  #define require101(exp) exp
+#else
+  #define require101(exp) require (exp)
+#endif
 #include "conf.h"
 #include "slog.h"
 #include "device.h"
 #include "vpn.h"
 #include "hkdf.h"
 #include "netcompat.h"
 #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
 #include "lzf/lzf.h"
 #include "lzf/lzf_c.c"
     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));
+    require101 (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";
 }
 static void
 auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
 {
-  hkdf kdf (&auth.ecdh, sizeof (auth.ecdh), AUTH_DIGEST ()); // use remote ecdh b as salt
+  hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
   kdf.extract (&auth.rsa, sizeof (auth.rsa));
   kdf.extract_done ();
-  kdf.expand (mac, sizeof mac, b, sizeof b); // use response ecdh b as info
+  kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
 }
 void
 connection::generate_auth_data ()
 {
 void
 hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
 {
   HMAC_CTX *hctx = &ctx->hctx;
-  require (HMAC_Init_ex (hctx, 0, 0, 0, 0));
+  require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
-  require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
+  require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
-  require (HMAC_Final (hctx, hmac_digest, 0));
+  require101 (HMAC_Final (hctx, hmac_digest, 0));
 }
 void
 hmac_packet::hmac_set (crypto_ctx *ctx)
 {
 bool
 hmac_packet::hmac_chk (crypto_ctx *ctx)
 {
   unsigned char hmac_digest[EVP_MAX_MD_SIZE];
   hmac_gen (ctx, hmac_digest);
-  return !memcmp (hmac, hmac_digest, HMACLENGTH);
+  return slow_memeq (hmac, hmac_digest, HMACLENGTH);
 }
 void
 vpn_packet::set_hdr (ptype type_, unsigned int dst)
 {
   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",
+        vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
         PROTOCOL_MAJOR, prot_minor);
   if (::conf.script_node_up)
     {
       run_script_cb *cb = new run_script_cb;
   // 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);
+  hmac_error = 0.;
   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);
+      if (p->len) send_data_packet (p);
-          delete p;
+      delete p;
-        }
+    }
-      while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
+  while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
-        {
+    {
-          if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
+      if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
-          delete p;
+      delete p;
-        }
     }
   vpn->connection_established (this);
 }
       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
 const sockinfo &
 connection::forward_si (const sockinfo &si) const
 void
 connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
 {
   if (!vpn->send_vpn_packet (pkt, si, tos))
-    reset_connection ();
+    reset_connection ("packet send error");
 }
 void
 connection::send_ping (const sockinfo &si, u8 pong)
 {
     {
       // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
       // and stop trying. should probably be handled by a per-connection expire handler.
       if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
         {
-          reset_connection ();
+          reset_connection ("no demand");
           return;
         }
       last_establish_attempt = ev_now ();
                                          ? (retry_cnt & 3) + 1
                                          : 1 << (retry_cnt >> 2));
       reset_si ();
-      bool slow = si.prot & PROT_SLOW;
+      bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
       if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
         {
           /*TODO*/ /* start the timer so we don't recurse endlessly */
           w.start (1);
           slow = slow || (dsi.prot & PROT_SLOW);
           if (dsi.valid () && auth_rate_limiter.can (dsi))
             {
-              if (retry_cnt < 4)
+              // use ping after the first few retries
+              // TODO: on rekeys, the other node might not interpret ping correctly,
+              // TODO: as it will still have a valid connection
+              if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
                 send_auth_request (dsi, true);
               else
                 send_ping (dsi, 0);
             }
         }
-      retry_int *= slow ? 8. : 0.9;
+      retry_int *= slow ? 4. : 0.9;
       if (retry_int < conf->max_retry)
         retry_cnt++;
       else
         retry_int = conf->max_retry;
       w.start (retry_int);
     }
 }
 void
-connection::reset_connection ()
+connection::reset_connection (const char *reason)
 {
   if (ictx && octx)
     {
-      slog (L_INFO, _("%s(%s): connection lost"),
+      slog (L_INFO, _("%s(%s): connection lost (%s)"),
-            conf->nodename, (const char *)si);
+            conf->nodename, (const char *)si, reason);
       if (::conf.script_node_down)
         {
           run_script_cb *cb = new run_script_cb;
           cb->set<connection, &connection::script_node_down> (this);
 connection::shutdown ()
 {
   if (ictx && octx)
     send_reset (si);
-  reset_connection ();
+  reset_connection ("shutdown");
 }
 // poor-man's rekeying
 inline void
 connection::rekey_cb (ev::timer &w, int revents)
 {
-  reset_connection ();
+  reset_connection ("rekeying");
   establish_connection ();
 }
 void
 connection::send_data_packet (tap_packet *pkt)
 void
 connection::post_inject_queue ()
 {
   // force a connection every now and when when packets are sent (max 1/s)
-  if (ev_now () - last_establish_attempt >= 0.95) // arbitrary
+  if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
     establish_connection.stop ();
   establish_connection ();
 }
         // about our desire for communication.
         establish_connection ();
         break;
       case vpn_packet::PT_RESET:
+          slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
+        if (ictx && octx)
-        {
+          {
-          reset_connection ();
+            reset_connection ("remote reset");
-          config_packet *p = (config_packet *) pkt;
+            config_packet *p = (config_packet *) pkt;
-          if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
+            if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
-            establish_connection ();
+              establish_connection ();
-        }
+          }
         break;
       case vpn_packet::PT_AUTH_REQ:
         if (auth_rate_limiter.can (rsi))
           {
                   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->initiate)
+                  {
-                  send_auth_request (rsi, false);
+                    send_auth_request (rsi, false);
+                    if (ictx && octx)
+                      reset_connection ("reconnect");
+                  }
                 auth_data auth;
                 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));
                   }
                 else
                   {
-                    bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth);
+                    bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
                     rcv_auth = auth;
                     have_rcv_auth = true;
                     send_auth_response (rsi);
           slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
           auth_mac local_mac;
           auth_hash (snd_auth, p->response.ecdh, local_mac);
-          if (memcmp (&p->response.mac, local_mac, sizeof local_mac))
+          if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
             {
               slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
                     conf->nodename, (const char *)rsi);
             }
           else if (!have_snd_auth)
               memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
               have_snd_auth = true;
               connection_established (rsi);
             }
-           break;
         }
-        send_reset (rsi);
         break;
       case vpn_packet::PT_DATA_COMPRESSED:
 #if !ENABLE_COMPRESSION
         send_reset (rsi);
         if (ictx && octx)
           {
             vpndata_packet *p = (vpndata_packet *)pkt;
             if (!p->hmac_chk (ictx))
+              {
+                // rekeying often creates temporary hmac auth floods
+                // we assume they don't take longer than a few seconds normally,
+                // and suppress messages and resets during that time.
+                //TODO: should be done per source address
+                if (!hmac_error)
+                  {
+                    hmac_error = ev_now () + 3;
+                    break;
+                  }
+                else if (hmac_error >= ev_now ())
+                  break; // silently suppress
+                else
+                  {
-              slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
+                    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);
+                          conf->nodename, (const char *)rsi);
+                    // reset
+                  }
+              }
             else
               {
                 u32 seqno;
                 tap_packet *d = p->unpack (this, seqno);
                 int seqclass = iseqno.seqno_classify (seqno);
+                hmac_error = 0;
                 if (seqclass == 0) // ok
                   {
                     vpn->tap->send (d);
   if (when >= 0)
     w.start (when);
   else if (when < -15)
     {
-      reset_connection ();
+      reset_connection ("keepalive overdue");
       establish_connection ();
     }
   else if (conf->connectmode != conf_node::C_ONDEMAND
            || THISNODE->connectmode != conf_node::C_ONDEMAND)
     {
   else if (when >= -10)
     // hold ondemand connections implicitly a few seconds longer
     // should delete octx, though, or something like that ;)
     w.start (when + 10);
   else
-    reset_connection ();
+    reset_connection ("keepalive timeout");
 }
 void
 connection::send_connect_request (int id)
 {
   // queue a dummy packet to force an initial connection attempt
   if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
     vpn_queue.put (new net_packet);
-  reset_connection ();
+  reset_connection ("startup");
 }
 connection::~connection ()
 {
   shutdown ();

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Comparing gvpe/src/connection.C (file contents): Revision 1.104 by root, Fri Jul 19 18:18:27 2013 UTC vs. Revision 1.112 by root, Fri Sep 12 10:40:43 2014 UTC

Diff Legend

Comparing gvpe/src/connection.C (file contents):
Revision 1.104 by root, Fri Jul 19 18:18:27 2013 UTC vs.
Revision 1.112 by root, Fri Sep 12 10:40:43 2014 UTC