X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=fe0d180e20fa56a3b186db2fd647828ebe70a613;hp=42b41ebc09e6118fe7485b6181a4a032b39bafe9;hb=9c2f805255fa36b05e8fe9391f639581d938b653;hpb=e9635ae38e0e2e3eb92568a1e234f8348856dd69

diff --git a/src/protocol.c b/src/protocol.c
index 42b41ebc..fe0d180e 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 1.28.4.39 2000/10/14 17:04:15 guus Exp $
+    $Id: protocol.c,v 1.28.4.45 2000/10/24 15:46:17 guus Exp $
 */
 
 #include "config.h"
@@ -52,40 +52,40 @@ int check_id(char *id)
   int i;
 
   for (i = 0; i < strlen(id); i++)
-    {
-      if(!isalpha(id[i]) && id[i] != '_')
-        {
-          return 0;
-        }
-    }
-
-  return 1;
+    if(!isalnum(id[i]) && id[i] != '_')
+      return -1;
+          
+  return 0;
 }
 
 /* Generic request routines - takes care of logging and error detection as well */
 
-int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
+int send_request(conn_list_t *cl, const char *format, ...)
 {
   va_list args;
-  char buffer[MAXBUFSIZE+1];
-  int len;
+  char buffer[MAXBUFSIZE];
+  int len, request;
 
 cp
   /* 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 = vsnprintf(buffer, MAXBUFSIZE+1, format, args);
+  va_start(args, format);
+  len = vsnprintf(buffer, MAXBUFSIZE, format, args);
+  request = va_arg(args, int);
   va_end(args);
 
-  if(len < 0 || len > MAXBUFSIZE)
+  if(len < 0 || len > MAXBUFSIZE-1)
     {
       syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
       return -1;
     }
 
+  len++;
+
   if(debug_lvl >= DEBUG_PROTOCOL)
     syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+
 cp
   return send_meta(cl, buffer, len);
 }
@@ -104,7 +104,7 @@ cp
         }
       else
         {
-          if(debug_lvl > DEBUG_PROTOCOL)
+          if(debug_lvl >= DEBUG_PROTOCOL)
             syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
 		   request_name[request], cl->name, cl->hostname);
 	}
@@ -155,14 +155,17 @@ cp
 int send_id(conn_list_t *cl)
 {
 cp
-  return send_request(cl, "%d %s %d %lx", ID, myself->name, myself->protocol_version, myself->options);
+  cl->allow_request = CHALLENGE;
+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)
 {
   conn_list_t *old;
+  config_t *cfg;
 cp
-  if(sscanf(cl->buffer, "%*d %as %d %lx", &cl->name, &cl->protocol_version, &cl->options) != 3)
+  if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->name, &cl->protocol_version, &cl->options, &cl->port) != 4)
     {
        syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
        return -1;
@@ -179,31 +182,30 @@ cp
 
   /* Check if identity is a valid name */
 
-  if(!check_id(cl->name))
+  if(check_id(cl->name))
     {
       syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
       return -1;
     }
 
   /* Load information about peer */
-
-  if(!read_host_config(cl))
+cp
+  if(read_host_config(cl))
     {
       syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name);
       return -1;
     }
 
-
   /* First check if the host we connected to is already in our
      connection list. If so, we are probably making a loop, which
      is not desirable.
    */
-
+cp
   if(cl->status.outgoing)
     {
       if((old = lookup_id(cl->name)))
         {
-          if(debug_lvl > DEBUG_CONNECTIONS)
+          if(debug_lvl >= DEBUG_CONNECTIONS)
             syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->name, cl->hostname);
           cl->status.outgoing = 0;
           old->status.outgoing = 1;
@@ -211,42 +213,84 @@ cp
           return 0;
         }
     }
+cp    
+  if(!(cfg = get_config_val(cl->config, publickey)))
+    {
+      syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname);
+      return -1;
+    }
+  else
+    {
+cp
+      cl->rsa_key = RSA_new();
+      BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
+      BN_hex2bn(&cl->rsa_key->e, "FFFF");
+    }
 
-  /* Send a challenge to verify the identity */
-
-  cl->allow_request = CHAL_REPLY;
 cp
   return send_challenge(cl);
 }
 
 int send_challenge(conn_list_t *cl)
 {
-  char buffer[CHAL_LENGTH*2+1];
+  char *buffer;
+  int len, x;
 cp
+  len = RSA_size(cl->rsa_key);
+
   /* Allocate buffers for the challenge */
 
-  if(!cl->hischallenge)
-    cl->hischallenge = xmalloc(CHAL_LENGTH);
+  buffer = xmalloc(len*2+1);
+
+  if(cl->hischallenge)
+    free(cl->hischallenge);
+    
+  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, CHAL_LENGTH);
+  RAND_bytes(cl->hischallenge, len);
 
-  /* Convert the random data to a hexadecimal formatted string */
+  cl->hischallenge[0] &= 0x7F;	/* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
 
-  bin2hex(cl->hischallenge,buffer,CHAL_LENGTH);
-  buffer[CHAL_LENGTH*2] = '\0';
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->hischallenge, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer);
+    }
+
+  /* Encrypt the random data */
+  
+  if(RSA_public_encrypt(len, cl->hischallenge, 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 challenge 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 challenge */
 
   cl->allow_request = CHAL_REPLY;
+  x = send_request(cl, "%d %s", CHALLENGE, buffer);
+  free(buffer);
 cp
-  return send_request(cl, "%d %s", CHALLENGE, buffer);
+  return x;
 }
 
 int challenge_h(conn_list_t *cl)
 {
   char *buffer;
+  int len;
 cp
   if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
     {
@@ -254,9 +298,11 @@ cp
        return -1;
     }
 
+  len = RSA_size(myself->rsa_key);
+
   /* Check if the length of the challenge is all right */
 
-  if(strlen(buffer) != CHAL_LENGTH*2)
+  if(strlen(buffer) != len*2)
     {
       syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname);
       free(buffer);
@@ -266,11 +312,28 @@ cp
   /* Allocate buffers for the challenge */
 
   if(!cl->mychallenge)
-    cl->mychallenge = xmalloc(CHAL_LENGTH);
+    cl->mychallenge = xmalloc(len);
 
   /* Convert the challenge from hexadecimal back to binary */
 
-  hex2bin(buffer,cl->mychallenge,CHAL_LENGTH);
+  hex2bin(buffer,buffer,len);
+
+  /* Decrypt the challenge */
+  
+  if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len)	/* See challenge() */
+    {
+      syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
+      free(buffer);
+      return -1;
+    }
+
+  if(debug_lvl >= DEBUG_SCARY_THINGS)
+    {
+      bin2hex(cl->mychallenge, buffer, len);
+      buffer[len*2] = '\0';
+      syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
+    }
+
   free(buffer);
     
   /* Rest is done by send_chal_reply() */
@@ -290,7 +353,7 @@ cp
      
   /* Calculate the hash from the challenge we received */
 
-  SHA1(cl->mychallenge, CHAL_LENGTH, hash);
+  SHA1(cl->mychallenge, RSA_size(myself->rsa_key), hash);
 
   /* Convert the hash to a hexadecimal formatted string */
 
@@ -313,7 +376,7 @@ int chal_reply_h(conn_list_t *cl)
   char *hishash;
   char myhash[SHA_DIGEST_LENGTH];
 cp
-  if(sscanf(cl->buffer, "%*d %as", &hishash) != 2)
+  if(sscanf(cl->buffer, "%*d %as", &hishash) != 1)
     {
        syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
        free(hishash);
@@ -335,17 +398,24 @@ cp
 
   /* Calculate the hash from the challenge we sent */
 
-  SHA1(cl->hischallenge, CHAL_LENGTH, myhash);
+  SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash);
 
   /* Verify the incoming hash with the calculated hash */
 
-  if(!memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
+  if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
     {
       syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname);
+      if(debug_lvl >= DEBUG_SCARY_THINGS)
+        {
+          bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
+          hishash[SHA_DIGEST_LENGTH*2] = '\0';
+          syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
+        }
       free(hishash);
       return -1;
     }
 
+
   free(hishash);
 
   /* Identity has now been positively verified.
@@ -354,19 +424,15 @@ cp
    */
 cp
   if(cl->status.outgoing)
-    {
-      cl->allow_request = ACK;
       return send_ack(cl);
-    }
   else
-    {
-      cl->allow_request = CHALLENGE;
       return send_id(cl);
-    }
 }
 
 int send_ack(conn_list_t *cl)
 {
+cp
+  cl->allow_request = ACK;
 cp
   return send_request(cl, "%d", ACK);
 }
@@ -382,7 +448,7 @@ cp
 
   while((old = lookup_id(cl->name)))
     {
-      if(debug_lvl > DEBUG_CONNECTIONS)
+      if(debug_lvl >= DEBUG_CONNECTIONS)
         syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
         cl->name, old->hostname, cl->hostname);
       old->status.active = 0;
@@ -394,7 +460,7 @@ cp
   cl->allow_request = ALL;
   cl->status.active = 1;
 
-  if(debug_lvl > DEBUG_CONNECTIONS)
+  if(debug_lvl >= DEBUG_CONNECTIONS)
     syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
 
   /* Exchange information about other tinc daemons */
@@ -403,7 +469,6 @@ cp
   notify_others(cl, NULL, send_add_host);
   notify_one(cl);
 */
-  upstreamindex = 0;
 
 cp
   if(cl->status.outgoing)
@@ -442,7 +507,7 @@ cp
 
   /* Check if owner name is a valid */
 
-  if(!check_id(name))
+  if(check_id(name))
     {
       syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
       free(name); free(subnetstr);
@@ -510,7 +575,7 @@ cp
 
   /* Check if owner name is a valid */
 
-  if(!check_id(name))
+  if(check_id(name))
     {
       syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
       free(name); free(subnetstr);
@@ -580,7 +645,7 @@ cp
 
   /* Check if identity is a valid name */
 
-  if(!check_id(new->name) || !check_id(sender))
+  if(check_id(new->name) || check_id(sender))
     {
       syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
       free(sender);
@@ -629,14 +694,14 @@ cp
     {
       if((new->address == old->address) && (new->port == old->port))
         {
-          if(debug_lvl > DEBUG_CONNECTIONS)
+          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);
           return 0;
         }
       else
         {
-          if(debug_lvl > DEBUG_CONNECTIONS)
+          if(debug_lvl >= DEBUG_CONNECTIONS)
             syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"),
                    old->name, old->hostname);
           old->status.active = 0;
@@ -687,7 +752,7 @@ cp
 
   /* Check if identity is a valid name */
 
-  if(!check_id(name) || !check_id(sender))
+  if(check_id(name) || check_id(sender))
     {
       syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
       free(name); free(sender);
@@ -778,7 +843,7 @@ cp
        return -1;
     }
 
-  if(debug_lvl > DEBUG_STATUS)
+  if(debug_lvl >= DEBUG_STATUS)
     {
       syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"),
              cl->name, cl->hostname, status_text[statusno], statusstring);
@@ -804,12 +869,12 @@ int error_h(conn_list_t *cl)
 cp
   if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2)
     {
-       syslog(LOG_ERR, _("Got bad error from %s (%s)"),
+       syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"),
               cl->name, cl->hostname);
        return -1;
     }
 
-  if(debug_lvl > DEBUG_error)
+  if(debug_lvl >= DEBUG_ERROR)
     {
       syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
              cl->name, cl->hostname, strerror(errno), errorstring);
@@ -1051,11 +1116,11 @@ char (*request_name[]) = {
 /* Status strings */
 
 char (*status_text[]) = {
-  "FIXME: status text",
+  "Warning",
 };
 
 /* Error strings */
 
 char (*error_text[]) = {
-  "FIXME: error text",
+  "Error",
 };