Encrypt network packets in CBC mode instead of CFB mode.

[tinc] / src / net.c

diff --git a/src/net.c b/src/net.c
index 18e5951..7ebe37b 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net.c,v 1.35.4.92 2001/01/07 20:19:29 guus Exp $
+    $Id: net.c,v 1.35.4.96 2001/02/25 16:34:17 guus Exp $
 */
 
 #include "config.h"
@@ -112,7 +112,7 @@ int xsend(connection_t *cl, vpn_packet_t *inpkt)
 cp
   outpkt.len = inpkt->len;
   
-  /* Encrypt the packet. FIXME: we should use CBC, not CFB. */
+  /* Encrypt the packet. */
   
   EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
   EVP_EncryptUpdate(&ctx, outpkt.data, &outlen, inpkt->data, inpkt->len);
@@ -202,6 +202,7 @@ int send_packet(ip_t to, vpn_packet_t *packet)
 {
   connection_t *cl;
   subnet_t *subnet;
+  vpn_packet_t *copy;
 cp
   if((subnet = lookup_subnet_ipv4(&to)) == NULL)
     {
@@ -242,7 +243,13 @@ cp
        syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
               cl->name, cl->hostname);
 
-      list_insert_tail(cl->queue, packet);
+      /* Since packet is on the stack of handle_tap_input(),
+         we have to make a copy of it first. */
+
+      copy = xmalloc(sizeof(vpn_packet_t));
+      memcpy(copy, packet, sizeof(vpn_packet_t));
+
+      list_insert_tail(cl->queue, copy);
 
       if(!cl->status.waitingforkey)
        send_req_key(myself, cl);                       /* Keys should be sent to the host running the tincd */
@@ -260,7 +267,7 @@ cp
 void flush_queue(connection_t *cl)
 {
   list_node_t *node, *next;
-
+cp
   if(debug_lvl >= DEBUG_TRAFFIC)
     syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
   
@@ -270,6 +277,7 @@ void flush_queue(connection_t *cl)
       xsend(cl, (vpn_packet_t *)node->data);
       list_delete_node(cl->queue, node);
     }
+cp
 }
 
 /*
@@ -610,17 +618,24 @@ int read_rsa_public_key(connection_t *cl)
 {
   config_t const *cfg;
   FILE *fp;
+  char *fname;
   void *result;
 cp
   if(!cl->rsa_key)
     cl->rsa_key = RSA_new();
 
+  /* First, check for simple PublicKey statement */
+
   if((cfg = get_config_val(cl->config, config_publickey)))
     {
       BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
       BN_hex2bn(&cl->rsa_key->e, "FFFF");
+      return 0;
     }
-  else if((cfg = get_config_val(cl->config, config_publickeyfile)))
+
+  /* Else, check for PublicKeyFile statement and read it */
+
+  if((cfg = get_config_val(cl->config, config_publickeyfile)))
     {
       if(is_safe_path(cfg->data.ptr))
         {
@@ -638,17 +653,31 @@ cp
                     cfg->data.ptr);
               return -1;
             }
+          return 0;
         }
       else
         return -1;
     }    
-  else
+
+  /* Else, check if a harnessed public key is in the config file */
+  
+  asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
+  if((fp = fopen(fname, "r")))
     {
-      syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
-      return -1;
+      result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
+      fclose(fp);
+      free(fname);
+      if(result)
+        return 0;
     }
+
+  free(fname);
+
+  /* Nothing worked. */
+
+  syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
 cp
-  return 0;
+  return -1;
 }
 
 int read_rsa_private_key(void)
@@ -787,7 +816,7 @@ cp
 cp
   /* Generate packet encryption key */
 
-  myself->cipher_pkttype = EVP_bf_cfb();
+  myself->cipher_pkttype = EVP_bf_cbc();
 
   myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
 
@@ -1032,6 +1061,7 @@ cp
     {
       syslog(LOG_ERR, _("System call `%s' failed: %m"),
             "getpeername");
+      close(sfd);
       return NULL;
     }
 
@@ -1141,37 +1171,40 @@ cp
   if(cl->status.remove)
     return;
 
-  cl->status.remove = 1;
-
   if(debug_lvl >= DEBUG_CONNECTIONS)
     syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
            cl->name, cl->hostname);
  
+  cl->status.remove = 1;
+  
   if(cl->socket)
     close(cl->socket);
   if(cl->status.meta)
     close(cl->meta_socket);
 
-  /* Find all connections that were lost because they were behind cl
-     (the connection that was dropped). */
-
   if(cl->status.meta)
-    for(node = connection_tree->head; node; node = node->next)
-      {
-        p = (connection_t *)node->data;
-        if(p->nexthop == cl && p != cl)
-          terminate_connection(p);
-      }
-
-  /* Inform others of termination if it was still active */
-
-  if(cl->status.active)
-    for(node = connection_tree->head; node; node = node->next)
-      {
-        p = (connection_t *)node->data;
-        if(p->status.meta && p->status.active && p!=cl)
-          send_del_host(p, cl);        /* Sounds like recursion, but p does not have a meta connection :) */
-      }
+    {
+    
+      /* Find all connections that were lost because they were behind cl
+         (the connection that was dropped). */
+
+        for(node = connection_tree->head; node; node = node->next)
+          {
+            p = (connection_t *)node->data;
+            if(p->nexthop == cl && p != cl)
+              terminate_connection(p);
+          }
+
+      /* Inform others of termination if it was still active */
+
+      if(cl->status.active)
+        for(node = connection_tree->head; node; node = node->next)
+          {
+            p = (connection_t *)node->data;
+            if(p->status.meta && p->status.active && p != cl)
+              send_del_host(p, cl);    /* Sounds like recursion, but p does not have a meta connection :) */
+          }
+    }
 
   /* Remove the associated subnets */