- Use CFB mode for encrypting packets: it works and we don't need padding.

[tinc] / src / protocol.c

diff --git a/src/protocol.c b/src/protocol.c
index 1bb3734..d3b34c9 100644 (file)
--- a/src/protocol.c
+++ b/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 1.28.4.48 2000/10/29 00:24:31 guus Exp $
+    $Id: protocol.c,v 1.28.4.52 2000/10/29 22:10:43 guus Exp $
 */
 
 #include "config.h"
@@ -38,9 +38,9 @@
 
 #include <openssl/sha.h>
 #include <openssl/rand.h>
+#include <openssl/evp.h>
 
 #include "conf.h"
-#include "encr.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
@@ -111,6 +111,12 @@ cp
                   request_name[request], cl->name, cl->hostname);
        }
 
+      if((cl->allow_request != ALL) && (cl->allow_request != request))
+        {
+          syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname);
+          return -1;
+        }
+
       if(request_handlers[request](cl))
        /* Something went wrong. Probably scriptkiddies. Terminate. */
         {
@@ -435,7 +441,8 @@ cp
 int send_ack(conn_list_t *cl)
 {
 cp
-  cl->allow_request = ACK;
+  if(cl->status.outgoing)
+    cl->allow_request = ACK;
 cp
   return send_request(cl, "%d", ACK);
 }
@@ -464,6 +471,8 @@ cp
   cl->allow_request = ALL;
   cl->status.active = 1;
   cl->nexthop = cl;
+  cl->cipher_pkttype = EVP_bf_cfb();
+  cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
 
   if(debug_lvl >= DEBUG_CONNECTIONS)
     syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
@@ -986,6 +995,7 @@ int req_key_h(conn_list_t *cl)
 {
   char *from_id, *to_id;
   conn_list_t *from, *to;
+  char pktkey[129];
 cp
   if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
     {
@@ -1006,7 +1016,9 @@ cp
 
   if(!strcmp(to_id, myself->name))
     {
-      send_ans_key(myself, from, myself->cipher_pktkey);
+      bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
+      pktkey[myself->cipher_pktkeylength*2] = '\0';
+      send_ans_key(myself, from, pktkey);
     }
   else
     {
@@ -1017,7 +1029,15 @@ cp
           free(from_id); free(to_id);
           return -1;
         }
-      send_req_key(from, to);
+        
+      if(to->status.validkey)  /* Proxy keys */
+        {
+          bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength);
+          pktkey[to->cipher_pktkeylength*2] = '\0';
+          send_ans_key(to, from, pktkey);
+        }
+      else
+        send_req_key(from, to);
     }
 
   free(from_id); free(to_id);
@@ -1053,43 +1073,42 @@ cp
       return -1;
     }
 
-  /* Check if this key request is for us */
+  /* Update origin's packet key */
 
-  if(!strcmp(to_id, myself->name))
+  keylength = strlen(pktkey);
+
+  if(keylength != from->cipher_pktkeylength*2)
     {
-      /* It is for us, convert it to binary and set the key with it. */
+      syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"),
+             cl->name, cl->hostname, from->name);
+      free(from_id); free(to_id); free(pktkey);
+      return -1;
+    }
 
-      keylength = strlen(pktkey);
+  if(from->cipher_pktkey)
+    free(from->cipher_pktkey);
 
-/* Don't do this... yet
-      if((keylength%2) || (keylength <= 0))
-        {
-          syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key"),
-                 cl->name, cl->hostname, from->name);
-          free(from_id); free(to_id); free(pktkey);
-          return -1;
-        }
-      keylength /= 2;
-      hex2bin(pktkey, pktkey, keylength);
-      BF_set_key(cl->cipher_pktkey, keylength, pktkey);
-*/
+  keylength /= 2;
+  hex2bin(pktkey, pktkey, keylength);
+  pktkey[keylength] = '\0';
+  from->cipher_pktkey = pktkey;
 
-      from->status.validkey = 1;
-      from->status.waitingforkey = 0;
-    }
-  else
+  from->status.validkey = 1;
+  from->status.waitingforkey = 0;
+    
+  if(strcmp(to_id, myself->name))
     {
       if(!(to = lookup_id(to_id)))
         {
           syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"),
                  cl->name, cl->hostname, to_id);
-          free(from_id); free(to_id); free(pktkey);
+          free(from_id); free(to_id);
           return -1;
         }
       send_ans_key(from, to, pktkey);
     }
 
-  free(from_id); free(to_id); free(pktkey);
+  free(from_id); free(to_id);
 cp
   return 0;
 }