- Updated authentication scheme.

- Removed all trailing spaces from all lines.
- Added things to add_ and del_subnet_h.

src/protocol.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: protocol.c,v 1.28.4.32 2000/09/15 12:58:40 zarq Exp $
+    $Id: protocol.c,v 1.28.4.33 2000/09/17 21:42:05 guus Exp $
 */
 
 #include "config.h"
@@ -66,26 +66,29 @@ int check_id(char *id)
 int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
 {
   va_list args;
-  char *buffer = NULL;
+  char buffer[MAXBUFSIZE+1];
   int len;
 
 cp
-  if(debug_lvl >= DEBUG_PROTOCOL)
-    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+  /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic,
+     and there is a limit on the input buffer anyway */
 
   va_start(args, request);
-  len = vasprintf(&buffer, format, args);
+  len = vsnprintf(buffer, MAXBUFSIZE+1, format, args);
   va_end(args);
 
-  if(len < 0 || !buffer)
+  if(len < 0 || len > MAXBUFSIZE)
     {
-      syslog(LOG_ERR, _("Error during vasprintf(): %m"));
+      syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
       return -1;
     }
 
   if(debug_lvl >= DEBUG_META)
-    syslog(LOG_DEBUG, _("Sending meta data to %s (%s): %s"),
+    syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request],
            cl->name, cl->hostname, buffer);
+  else if(debug_lvl >= DEBUG_PROTOCOL)
+    syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+
 
   if(cl->status.encryptin)
     {
@@ -105,20 +108,27 @@ cp
    Client               Server
    send_id(u)
                         send_challenge(R)
-   send_chal_reply(BH)                   
-                        send_id(B)
-   send_challenge(BR)
-                        send_chal_reply(BH)
-   send_ack(B)
-			send_ack(B)
+   send_chal_reply(H)
+                        send_id(u)
+   send_challenge(R)
+                        send_chal_reply(H)
+   ---------------------------------------
+   Any negotations about the meta protocol
+   encryption go here(u).
+   ---------------------------------------
+   send_ack(u)
+                        send_ack(u)
+   ---------------------------------------
+   Other requests(E)...
 
    (u) Unencrypted,
    (R) RSA,
    (H) SHA1,
-   (B) Blowfish.
+   (E) Encrypted with symmetric cipher.
 
-   Part of the challenge is directly used to set the blowfish key and the initial vector.
-   (Twee vliegen in één klap!)
+   Part of the challenge is directly used to set the symmetric cipher key and the initial vector.
+   Since a man-in-the-middle cannot decrypt the RSA challenges, this means that he cannot get or
+   forge the key for the symmetric cipher.
 */
 
 int send_id(conn_list_t *cl)
@@ -427,14 +437,58 @@ cp
 int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
 {
 cp
-/*  return send_request(cl, "%d %s %d %s", ADD_SUBNET,
-		      other->name, subnet->type, net2str(subnet)); */
   return send_request(cl, "%d %s %s", ADD_SUBNET,
                       other->name, net2str(subnet));
 }
 
 int add_subnet_h(conn_list_t *cl)
 {
+  char *subnetstr;
+  char *name;
+  conn_list_t *owner;
+  subnet_t *subnet, *old;
+cp
+  if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+    {
+       syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
+
+  /* Check if owner name is a valid */
+
+  if(!check_id(name))
+    {
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if subnet string is valid */
+
+  if((subnet = str2net(subnetstr)) == -1)
+    {
+      syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      return -1;
+    }
+  
+  /* Check if somebody tries to add a subnet of ourself */
+
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      sighup = 1;
+      return 0;
+    }
+
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name))
+    {
+      syslog(LOG_NOTICE, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+    }
+
+
 }
 
 int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
@@ -445,6 +499,50 @@ cp
 
 int del_subnet_h(conn_list_t *cl)
 {
+  char *subnetstr;
+  char *name;
+  conn_list_t *owner;
+  subnet_t *subnet, *old;
+cp
+  if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+    {
+       syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
+
+  /* Check if owner name is a valid */
+
+  if(!check_id(name))
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if subnet string is valid */
+
+  if((subnet = str2net(subnetstr)) == -1)
+    {
+      syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+      return -1;
+    }
+
+  /* Check if somebody tries to delete a subnet of ourself */
+
+  if(!strcmp(name, myself->name))
+    {
+      syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"),
+             cl->name, cl->hostname);
+      sighup = 1;
+      return 0;
+    }
+
+  /* Check if the owner of the new subnet is in the connection list */
+
+  if(!(owner = lookup_id(name))
+    {
+      syslog(LOG_NOTICE, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"),
+             name, cl->name, cl->hostname);
+    }
 }
 
 /* New and closed connections notification */