X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=75818043782f0ec57e8298227d3af55d77e3c945;hp=71b136769bb4819d4103cff7cecb4752aa812aa0;hb=408ca91766088b6c2d38e198b0692bf394b41248;hpb=35932fe6c8cb481eb687f98424776ce429570c21

diff --git a/src/protocol.c b/src/protocol.c
index 71b13676..75818043 100644
--- 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 1.28.4.47 2000/10/29 00:02:19 guus Exp $
+    $Id: protocol.c,v 1.28.4.62 2000/11/20 19:12:13 guus Exp $
 */
 
 #include "config.h"
@@ -30,22 +30,38 @@
 #include <sys/socket.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdarg.h>
 
 #include <utils.h>
 #include <xalloc.h>
 
 #include <netinet/in.h>
 
-#include <openssl/sha.h>
-#include <openssl/rand.h>
+#ifdef HAVE_OPENSSL_SHA_H
+# include <openssl/sha.h>
+#else
+# include <sha.h>
+#endif
+
+#ifdef HAVE_OPENSSL_RAND_H
+# include <openssl/rand.h>
+#else
+# include <rand.h>
+#endif
+
+#ifdef HAVE_OPENSSL_EVP_H
+# include <openssl/evp.h>
+#else
+# include <evp.h>
+#endif
+
 
 #include "conf.h"
-#include "encr.h"
 #include "net.h"
 #include "netutl.h"
 #include "protocol.h"
 #include "meta.h"
-#include "connlist.h"
+#include "connection.h"
 
 #include "system.h"
 
@@ -62,7 +78,7 @@ int check_id(char *id)
 
 /* Generic request routines - takes care of logging and error detection as well */
 
-int send_request(conn_list_t *cl, const char *format, ...)
+int send_request(connection_t *cl, const char *format, ...)
 {
   va_list args;
   char buffer[MAXBUFSIZE];
@@ -92,7 +108,7 @@ cp
   return send_meta(cl, buffer, len);
 }
 
-int receive_request(conn_list_t *cl)
+int receive_request(connection_t *cl)
 {
   int request;
 cp  
@@ -111,6 +127,12 @@ 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. */
         {
@@ -139,8 +161,8 @@ cp
    send_challenge(R)
                         send_chal_reply(H)
    ---------------------------------------
-   Any negotations about the meta protocol
-   encryption go here(u).
+   send_metakey(R)
+                        send_metakey(R)
    ---------------------------------------
    send_ack(u)
                         send_ack(u)
@@ -157,7 +179,7 @@ cp
    forge the key for the symmetric cipher.
 */
 
-int send_id(conn_list_t *cl)
+int send_id(connection_t *cl)
 {
 cp
   cl->allow_request = CHALLENGE;
@@ -165,10 +187,10 @@ cp
   return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port);
 }
 
-int id_h(conn_list_t *cl)
+int id_h(connection_t *cl)
 {
-  conn_list_t *old;
-  config_t *cfg;
+  connection_t *old;
+  config_t const *cfg;
 cp
   if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->name, &cl->protocol_version, &cl->options, &cl->port) != 4)
     {
@@ -219,7 +241,7 @@ cp
         }
     }
 cp    
-  if((cfg = get_config_val(cl->config, publickey)))
+  if((cfg = get_config_val(cl->config, config_publickey)))
     {
       cl->rsa_key = RSA_new();
       BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
@@ -234,7 +256,7 @@ cp
   return send_challenge(cl);
 }
 
-int send_challenge(conn_list_t *cl)
+int send_challenge(connection_t *cl)
 {
   char *buffer;
   int len, x;
@@ -250,10 +272,6 @@ cp
     
   cl->hischallenge = xmalloc(len);
 cp
-  /* Seed the PRNG with urandom (can't afford to block) */
-
-  RAND_load_file("/dev/urandom", 1024);
-
   /* Copy random data to the buffer */
 
   RAND_bytes(cl->hischallenge, len);
@@ -290,7 +308,7 @@ cp
   return x;
 }
 
-int challenge_h(conn_list_t *cl)
+int challenge_h(connection_t *cl)
 {
   char *buffer;
   int len;
@@ -344,7 +362,7 @@ cp
   return send_chal_reply(cl);
 }
 
-int send_chal_reply(conn_list_t *cl)
+int send_chal_reply(connection_t *cl)
 {
   char hash[SHA_DIGEST_LENGTH*2+1];
 cp
@@ -368,13 +386,13 @@ cp
   if(cl->status.outgoing)
     cl->allow_request = ID;
   else
-    cl->allow_request = ACK;
+    cl->allow_request = METAKEY;
 
 cp
   return send_request(cl, "%d %s", CHAL_REPLY, hash);
 }
 
-int chal_reply_h(conn_list_t *cl)
+int chal_reply_h(connection_t *cl)
 {
   char *hishash;
   char myhash[SHA_DIGEST_LENGTH];
@@ -427,23 +445,151 @@ cp
    */
 cp
   if(cl->status.outgoing)
-      return send_ack(cl);
+      return send_metakey(cl);
   else
       return send_id(cl);
 }
 
-int send_ack(conn_list_t *cl)
+int send_metakey(connection_t *cl)
+{
+  char *buffer;
+  int len, x;
+cp
+  len = RSA_size(cl->rsa_key);
+
+  /* Allocate buffers for the meta key */
+
+  buffer = xmalloc(len*2+1);
+
+  if(!cl->cipher_outkey)
+    cl->cipher_outkey = xmalloc(len);
+    
+  if(!cl->cipher_outctx)
+    cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx));
+cp
+  /* Copy random data to the buffer */
+
+  RAND_bytes(cl->cipher_outkey, len);
+
+  cl->cipher_outkey[0] &= 0x7F;	/* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
+
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->cipher_outkey, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
+    }
+
+  /* Encrypt the random data */
+  
+  if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len)	/* NO_PADDING because the message size equals the RSA key size and it is totally random */
+    {
+      syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
+      return -1;
+    }
+cp
+  /* Convert the encrypted random data to a hexadecimal formatted string */
+
+  bin2hex(buffer, buffer, len);
+  buffer[len*2] = '\0';
+
+  /* Send the meta key */
+
+  if(cl->status.outgoing)
+    cl->allow_request = METAKEY;
+  else
+    cl->allow_request = ACK;
+    
+  x = send_request(cl, "%d %s", METAKEY, buffer);
+  free(buffer);
+
+  EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len);
+cp
+  return x;
+}
+
+int metakey_h(connection_t *cl)
+{
+  char *buffer;
+  int len;
+cp
+  if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
+    {
+       syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname);
+       return -1;
+    }
+
+  len = RSA_size(myself->rsa_key);
+
+  /* Check if the length of the meta key is all right */
+
+  if(strlen(buffer) != len*2)
+    {
+      syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
+      return -1;
+    }
+
+  /* Allocate buffers for the meta key */
+
+  if(!cl->cipher_inkey)
+    cl->cipher_inkey = xmalloc(len);
+
+  if(!cl->cipher_inctx)
+    cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx));
+
+  /* Convert the challenge from hexadecimal back to binary */
+
+  hex2bin(buffer,buffer,len);
+
+  /* Decrypt the meta key */
+  
+  if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len)	/* See challenge() */
+    {
+      syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
+      return -1;
+    }
+
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->cipher_inkey, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
+    }
+
+  free(buffer);
+
+  EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
+  
+cp
+  if(cl->status.outgoing)
+    return send_ack(cl);
+  else
+    return send_metakey(cl);
+}
+
+int send_ack(connection_t *cl)
 {
+  int x;
 cp
-  cl->allow_request = ACK;
+  if(cl->status.outgoing)
+    cl->allow_request = ACK;
+
+  setup_vpn_connection(cl);
+
+  x = send_request(cl, "%d", ACK);
+  cl->status.encryptout = 1;
 cp
-  return send_request(cl, "%d", ACK);
+  return x;
 }
 
-int ack_h(conn_list_t *cl)
+int ack_h(connection_t *cl)
 {
-  conn_list_t *old, *p;
-  subnet_t *s;
+  connection_t *old, *p;
+  subnet_t *subnet;
+  rbl_t *rbl, *rbl2;
 cp
   /* Okay, before we active the connection, we check if there is another entry
      in the connection list with the same name. If so, it presumably is an
@@ -463,7 +609,10 @@ cp
 
   cl->allow_request = ALL;
   cl->status.active = 1;
+  cl->status.decryptin = 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);
@@ -474,33 +623,42 @@ cp
 
   /* Send him our subnets */
   
-  for(s = myself->subnets; s; s = s->next)
-    send_add_subnet(cl, s);
-
+  RBL_FOREACH(myself->subnet_tree, rbl)
+    {
+      subnet = (subnet_t *)rbl->data;
+      send_add_subnet(cl, subnet);
+    }
   /* And send him all the hosts and their subnets we know... */
   
-  for(p = conn_list; p; p = p->next)
-    if(p != cl && p->status.active)
-      {
-        /* Notify others of this connection */
-  
-        if(p->status.meta)
-          send_add_host(p, cl);
+  RBL_FOREACH(connection_tree, rbl)
+    {
+      p = (connection_t *)rbl->data;
+      
+      if(p != cl && p->status.active)
+        {
+          /* Notify others of this connection */
 
-        /* Notify new connection of everything we know */
+          if(p->status.meta)
+            send_add_host(p, cl);
 
-        send_add_host(cl, p);
-        
-        for(s = p->subnets; s; s = s->next)
-          send_add_subnet(cl, s);
-      }
+          /* Notify new connection of everything we know */
+
+          send_add_host(cl, p);
+
+          RBL_FOREACH(p->subnet_tree, rbl2)
+            {
+              subnet = (subnet_t *)rbl2->data;
+              send_add_subnet(cl, subnet);
+            }
+        }
+    }  
 cp
   return 0;
 }
 
 /* Address and subnet information exchange */
 
-int send_add_subnet(conn_list_t *cl, subnet_t *subnet)
+int send_add_subnet(connection_t *cl, subnet_t *subnet)
 {
   int x;
   char *netstr;
@@ -512,12 +670,13 @@ cp
   return x;
 }
 
-int add_subnet_h(conn_list_t *cl)
+int add_subnet_h(connection_t *cl)
 {
   char *subnetstr;
   char *name;
-  conn_list_t *owner, *p;
+  connection_t *owner, *p;
   subnet_t *subnet;
+  rbl_t *rbl;
 cp
   if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 2)
     {
@@ -573,14 +732,17 @@ cp
 
   /* Tell the rest */
   
-  for(p = conn_list; p; p = p->next)
-    if(p->status.meta && p->status.active && p!= cl)
-      send_add_subnet(p, subnet);
+  RBL_FOREACH(connection_tree, rbl)
+    {
+      p = (connection_t *)rbl->data;
+      if(p->status.meta && p->status.active && p!= cl)
+        send_add_subnet(p, subnet);
+    }
 cp
   return 0;
 }
 
-int send_del_subnet(conn_list_t *cl, subnet_t *subnet)
+int send_del_subnet(connection_t *cl, subnet_t *subnet)
 {
   int x;
   char *netstr;
@@ -592,12 +754,13 @@ cp
   return x;
 }
 
-int del_subnet_h(conn_list_t *cl)
+int del_subnet_h(connection_t *cl)
 {
   char *subnetstr;
   char *name;
-  conn_list_t *owner, *p;
+  connection_t *owner, *p;
   subnet_t *subnet;
+  rbl_t *rbl;
 cp
   if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
     {
@@ -653,28 +816,31 @@ cp
 
   /* Tell the rest */
   
-  for(p = conn_list; p; p = p->next)
-    if(p->status.meta && p->status.active && p!= cl)
-      send_del_subnet(p, subnet);
+  RBL_FOREACH(connection_tree, rbl)
+    {
+      p = (connection_t *)rbl->data;
+      if(p->status.meta && p->status.active && p!= cl)
+        send_del_subnet(p, subnet);
+    }
 cp
   return 0;
 }
 
 /* New and closed connections notification */
 
-int send_add_host(conn_list_t *cl, conn_list_t *other)
+int send_add_host(connection_t *cl, connection_t *other)
 {
 cp
   return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
                       other->name, other->address, other->port, other->options);
 }
 
-int add_host_h(conn_list_t *cl)
+int add_host_h(connection_t *cl)
 {
-  conn_list_t *old, *new;
-  conn_list_t *p;
+  connection_t *old, *new, *p;
+  rbl_t *rbl;
 cp
-  new = new_conn_list();
+  new = new_connection();
 
   if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &new->name, &new->address, &new->port, &new->options) != 4)
     {
@@ -687,7 +853,7 @@ cp
   if(check_id(new->name))
     {
       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
-      free_conn_list(new);
+      free_connection(new);
       return -1;
     }
 
@@ -697,11 +863,11 @@ cp
     {
       syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
       sighup = 1;
-      free_conn_list(new);
+      free_connection(new);
       return 0;
     }
     
-  /* Fill in more of the new conn_list structure */
+  /* Fill in more of the new connection structure */
 
   new->hostname = hostlookup(htonl(new->address));
 
@@ -714,7 +880,7 @@ cp
           if(debug_lvl >= DEBUG_CONNECTIONS)
             syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"),
                    old->name, old->hostname, new->name, new->hostname);
-          free_conn_list(new);
+          free_connection(new);
           return 0;
         }
       else
@@ -727,39 +893,50 @@ cp
         }
     }
 
-  /* Hook it up into the conn_list */
+  /* Hook it up into the connection */
 
-  conn_list_add(new);
+  connection_add(new);
 
   /* Tell the rest about the new host */
 
-  for(p = conn_list; p; p = p->next)
-    if(p->status.meta && p->status.active && p!=cl)
-      send_add_host(p, new);
+  RBL_FOREACH(connection_tree, rbl)
+    {
+      p = (connection_t *)rbl->data;
+      if(p->status.meta && p->status.active && p!=cl)
+        send_add_host(p, new);
+    }
 
-  /* Fill in rest of conn_list structure */
+  /* Fill in rest of connection structure */
 
   new->nexthop = cl;
   new->status.active = 1;
+  new->cipher_pkttype = EVP_bf_cfb();
+  new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
 
+  /* Okay this is a bit ugly... it would be better to setup UDP sockets dynamically, or
+   * perhaps just one UDP socket... but then again, this has benefits too...
+   */
+   
+  setup_vpn_connection(new);
 cp
   return 0;
 }
 
-int send_del_host(conn_list_t *cl, conn_list_t *other)
+int send_del_host(connection_t *cl, connection_t *other)
 {
 cp
   return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
                       other->name, other->address, other->port, other->options);
 }
 
-int del_host_h(conn_list_t *cl)
+int del_host_h(connection_t *cl)
 {
   char *name;
   ip_t address;
   port_t port;
   long int options;
-  conn_list_t *old, *p;
+  connection_t *old, *p;
+  rbl_t *rbl;
 cp
   if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &name, &address, &port, &options) != 4)
     {
@@ -813,16 +990,19 @@ cp
 
   /* Tell the rest about the new host */
 
-  for(p = conn_list; p; p = p->next)
-    if(p->status.meta && p->status.active && p!=cl)
-      send_del_host(p, old);
+  RBL_FOREACH(connection_tree, rbl)
+    {
+      p = (connection_t *)rbl->data;
+      if(p->status.meta && p->status.active && p!=cl)
+        send_del_host(p, old);
+    }
 cp
   return 0;
 }
 
 /* Status and error notification routines */
 
-int send_status(conn_list_t *cl, int statusno, char *statusstring)
+int send_status(connection_t *cl, int statusno, char *statusstring)
 {
 cp
   if(!statusstring)
@@ -831,7 +1011,7 @@ cp
   return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
 }
 
-int status_h(conn_list_t *cl)
+int status_h(connection_t *cl)
 {
   int statusno;
   char *statusstring;
@@ -854,7 +1034,7 @@ cp
   return 0;
 }
 
-int send_error(conn_list_t *cl, int errno, char *errstring)
+int send_error(connection_t *cl, int errno, char *errstring)
 {
 cp
   if(!errstring)
@@ -862,7 +1042,7 @@ cp
   return send_request(cl, "%d %d %s", ERROR, errno, errstring);
 }
 
-int error_h(conn_list_t *cl)
+int error_h(connection_t *cl)
 {
   int errno;
   char *errorstring;
@@ -886,13 +1066,13 @@ cp
   return 0;
 }
 
-int send_termreq(conn_list_t *cl)
+int send_termreq(connection_t *cl)
 {
 cp
   return send_request(cl, "%d", TERMREQ);
 }
 
-int termreq_h(conn_list_t *cl)
+int termreq_h(connection_t *cl)
 {
 cp
   terminate_connection(cl);
@@ -902,53 +1082,56 @@ cp
 
 /* Keepalive routines - FIXME: needs a closer look */
 
-int send_ping(conn_list_t *cl)
+int send_ping(connection_t *cl)
 {
+cp
   cl->status.pinged = 1;
+  cl->last_ping_time = time(NULL);
 cp
   return send_request(cl, "%d", PING);
 }
 
-int ping_h(conn_list_t *cl)
+int ping_h(connection_t *cl)
 {
 cp
   return send_pong(cl);
 }
 
-int send_pong(conn_list_t *cl)
+int send_pong(connection_t *cl)
 {
 cp
   return send_request(cl, "%d", PONG);
 }
 
-int pong_h(conn_list_t *cl)
+int pong_h(connection_t *cl)
 {
 cp
-  cl->status.got_pong = 1;
+  cl->status.pinged = 0;
 cp
   return 0;
 }
 
 /* Key exchange */
 
-int send_key_changed(conn_list_t *from, conn_list_t *cl)
+int send_key_changed(connection_t *from, connection_t *cl)
 {
-  conn_list_t *p;
+  connection_t *p;
+  rbl_t *rbl;
 cp
-  for(p = conn_list; p != NULL; p = p->next)
+  RBL_FOREACH(connection_tree, rbl)
     {
-      if(p!=cl && p->status.meta && p->status.active)
-        send_request(p, "%d %s", KEY_CHANGED,
-                     from->name);
+      p = (connection_t *)rbl->data;
+      if(p != cl && p->status.meta && p->status.active)
+        send_request(p, "%d %s", KEY_CHANGED, from->name);
     }
 cp
   return 0;
 }
 
-int key_changed_h(conn_list_t *cl)
+int key_changed_h(connection_t *cl)
 {
   char *from_id;
-  conn_list_t *from;
+  connection_t *from;
 cp
   if(sscanf(cl->buffer, "%*d %as", &from_id) != 1)
     {
@@ -975,17 +1158,18 @@ cp
   return 0;
 }
 
-int send_req_key(conn_list_t *from, conn_list_t *to)
+int send_req_key(connection_t *from, connection_t *to)
 {
 cp
   return send_request(to->nexthop, "%d %s %s", REQ_KEY,
                       from->name, to->name);
 }
 
-int req_key_h(conn_list_t *cl)
+int req_key_h(connection_t *cl)
 {
   char *from_id, *to_id;
-  conn_list_t *from, *to;
+  connection_t *from, *to;
+  char pktkey[129];
 cp
   if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
     {
@@ -1006,7 +1190,9 @@ 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 +1203,15 @@ 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);
@@ -1025,18 +1219,18 @@ cp
   return 0;
 }
 
-int send_ans_key(conn_list_t *from, conn_list_t *to, char *pktkey)
+int send_ans_key(connection_t *from, connection_t *to, char *pktkey)
 {
 cp
   return send_request(to->nexthop, "%d %s %s %s", ANS_KEY,
                       from->name, to->name, pktkey);
 }
 
-int ans_key_h(conn_list_t *cl)
+int ans_key_h(connection_t *cl)
 {
   char *from_id, *to_id, *pktkey;
   int keylength;
-  conn_list_t *from, *to;
+  connection_t *from, *to;
 cp
   if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &pktkey) != 3)
     {
@@ -1053,51 +1247,54 @@ cp
       return -1;
     }
 
-  /* Check if this key request is for us */
+  /* Check correctness of packet key */
 
-  if(!strcmp(to_id, myself->name))
-    {
-      /* It is for us, convert it to binary and set the key with it. */
+  keylength = strlen(pktkey);
 
-      keylength = strlen(pktkey);
+  if(keylength != from->cipher_pktkeylength*2)
+    {
+      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;
+    }
 
-/* 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);
-*/
+  /* Forward it if necessary */
 
-      cl->status.validkey = 1;
-      cl->status.waitingforkey = 0;
-    }
-  else
+  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);
+  /* Update our copy of the origin's packet key */
+
+  if(from->cipher_pktkey)
+    free(from->cipher_pktkey);
+
+  keylength /= 2;
+  hex2bin(pktkey, pktkey, keylength);
+  pktkey[keylength] = '\0';
+  from->cipher_pktkey = pktkey;
+
+  from->status.validkey = 1;
+  from->status.waitingforkey = 0;
+    
+  free(from_id); free(to_id);
 cp
   return 0;
 }
 
 /* Jumptable for the request handlers */
 
-int (*request_handlers[])(conn_list_t*) = {
-  id_h, challenge_h, chal_reply_h, ack_h,
+int (*request_handlers[])(connection_t*) = {
+  id_h, challenge_h, chal_reply_h, metakey_h, ack_h,
   status_h, error_h, termreq_h,
   ping_h, pong_h,
   add_host_h, del_host_h,
@@ -1108,7 +1305,7 @@ int (*request_handlers[])(conn_list_t*) = {
 /* Request names */
 
 char (*request_name[]) = {
-  "ID", "CHALLENGE", "CHAL_REPLY", "ACK",
+  "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK",
   "STATUS", "ERROR", "TERMREQ",
   "PING", "PONG",
   "ADD_HOST", "DEL_HOST",