Protocol now also exchanges cipher/digest/maclength/compression for the

meta connection.

src/connection.h

@@ -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: connection.h,v 1.1.2.25 2002/02/18 16:25:16 guus Exp $
+    $Id: connection.h,v 1.1.2.26 2002/02/20 19:25:09 guus Exp $
 */
 
 #ifndef __TINC_CONNECTION_H__
@@ -80,14 +80,20 @@ typedef struct connection_t {
   struct edge_t *edge;             /* edge associated with this connection */
 
   RSA *rsa_key;                    /* his public/private key */
-  EVP_CIPHER *incipher;            /* Cipher he will use to send data to us */
+  const EVP_CIPHER *incipher;      /* Cipher he will use to send data to us */
-  EVP_CIPHER *outcipher;           /* Cipher we will use to send data to him */
+  const EVP_CIPHER *outcipher;     /* Cipher we will use to send data to him */
   EVP_CIPHER_CTX *inctx;           /* Context of encrypted meta data that will come from him to us */
   EVP_CIPHER_CTX *outctx;          /* Context of encrypted meta data that will be sent from us to him */
   char *inkey;                     /* His symmetric meta key + iv */
   char *outkey;                    /* Our symmetric meta key + iv */
   int inkeylength;                 /* Length of his key + iv */
   int outkeylength;                /* Length of our key + iv */
+  const EVP_MD *indigest;
+  const EVP_MD *outdigest;
+  int inmaclength;
+  int outmaclength;
+  int incompression;
+  int outcompression;
   char *mychallenge;               /* challenge we received from him */
   char *hischallenge;              /* challenge we sent to him */
 

src/net_setup.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_setup.c,v 1.1.2.2 2002/02/20 16:04:39 guus Exp $
+    $Id: net_setup.c,v 1.1.2.3 2002/02/20 19:25:09 guus Exp $
 */
 
 #include "config.h"
@@ -382,6 +382,8 @@ cp
   else
     myself->keylength = 1;
 
+  myself->connection->outcipher = EVP_bf_ofb();
+
   myself->key = (char *)xmalloc(myself->keylength);
   RAND_pseudo_bytes(myself->key, myself->keylength);
 
@@ -410,6 +412,8 @@ cp
   else
     myself->digest = EVP_sha1();
 
+  myself->connection->outdigest = EVP_sha1();
+
   if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->maclength))
     {
       if(myself->digest)
@@ -429,6 +433,8 @@ cp
   else
     myself->maclength = 4;
 
+  myself->connection->outmaclength = 0;
+
   /* Compression */
 
   if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->compression))
@@ -441,6 +447,8 @@ cp
     }
   else
     myself->compression = 0;
+
+  myself->connection->outcompression = 0;
 cp
   /* Done */
 

src/net_socket.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_socket.c,v 1.1.2.1 2002/02/18 16:25:16 guus Exp $
+    $Id: net_socket.c,v 1.1.2.2 2002/02/20 19:25:09 guus Exp $
 */
 
 #include "config.h"
@@ -375,6 +375,10 @@ cp
 
   c = new_connection();
   c->name = xstrdup(outgoing->name);
+  c->outcipher = myself->connection->outcipher;
+  c->outdigest = myself->connection->outdigest;
+  c->outmaclength = myself->connection->outmaclength;
+  c->outcompression = myself->connection->outcompression;
 
   init_configuration(&c->config_tree);
   read_connection_config(c);
@@ -415,6 +419,10 @@ cp
     }
 
   c = new_connection();
+  c->outcipher = myself->connection->outcipher;
+  c->outdigest = myself->connection->outdigest;
+  c->outmaclength = myself->connection->outmaclength;
+  c->outcompression = myself->connection->outcompression;
 
   c->address = sa;
   c->hostname = sockaddr2hostname(&sa);

src/protocol_auth.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_auth.c,v 1.1.4.2 2002/02/18 16:25:16 guus Exp $
+    $Id: protocol_auth.c,v 1.1.4.3 2002/02/20 19:25:09 guus Exp $
 */
 
 #include "config.h"
@@ -195,15 +195,20 @@ cp
 
   /* Send the meta key */
 
-  x = send_request(c, "%d %s", METAKEY, buffer);
+  x = send_request(c, "%d %d %d %d %d %s", METAKEY,
+                   c->outcipher?c->outcipher->nid:0, c->outdigest?c->outdigest->type:0,
+		   c->outmaclength, c->outcompression, buffer);
 
   /* Further outgoing requests are encrypted with the key we just generated */
 
-  EVP_EncryptInit(c->outctx, EVP_bf_cfb(),
+  if(c->outcipher)
-                  c->outkey + len - EVP_bf_cfb()->key_len,
+    {
-                  c->outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
+      EVP_EncryptInit(c->outctx, c->outcipher,
+                      c->outkey + len - c->outcipher->key_len,
+                      c->outkey + len - c->outcipher->key_len - c->outcipher->iv_len);
 
-  c->status.encryptout = 1;
+      c->status.encryptout = 1;
+    }
 cp
   return x;
 }
@@ -211,9 +216,10 @@ cp
 int metakey_h(connection_t *c)
 {
   char buffer[MAX_STRING_SIZE];
+  int cipher, digest, maclength, compression;
   int len;
 cp
-  if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1)
+  if(sscanf(c->buffer, "%*d %d %d %d %d "MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5)
     {
        syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname);
        return -1;
@@ -258,11 +264,51 @@ cp
 
   /* All incoming requests will now be encrypted. */
 cp
-  EVP_DecryptInit(c->inctx, EVP_bf_cfb(),
+  /* Check and lookup cipher and digest algorithms */
-                  c->inkey + len - EVP_bf_cfb()->key_len,
-                  c->inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len);
 
-  c->status.decryptin = 1;
+  if(cipher)
+    {
+      c->incipher = EVP_get_cipherbynid(cipher);
+      if(!c->incipher)
+	{
+	  syslog(LOG_ERR, _("%s (%s) uses unknown cipher!"), c->name, c->hostname);
+	  return -1;
+	}
+
+      EVP_DecryptInit(c->inctx, c->incipher,
+                      c->inkey + len - c->incipher->key_len,
+                      c->inkey + len - c->incipher->key_len - c->incipher->iv_len);
+
+      c->status.decryptin = 1;
+    }
+  else
+    {
+      c->incipher = NULL;
+    }
+
+  c->inmaclength = maclength;
+
+  if(digest)
+    {
+      c->indigest = EVP_get_digestbynid(digest);
+      if(!c->indigest)
+	{
+	  syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), c->name, c->hostname);
+	  return -1;
+	}
+      
+      if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0)
+	{
+	  syslog(LOG_ERR, _("%s (%s) uses bogus MAC length!"), c->name, c->hostname);
+	  return -1;
+	}
+    }
+  else
+    {
+      c->indigest = NULL;
+    }
+
+  c->incompression = compression;
 
   c->allow_request = CHALLENGE;
 cp
@@ -340,16 +386,19 @@ cp
 
 int send_chal_reply(connection_t *c)
 {
-  char hash[SHA_DIGEST_LENGTH*2+1];
+  char hash[EVP_MAX_MD_SIZE*2+1];
+  EVP_MD_CTX ctx;
 cp
   /* Calculate the hash from the challenge we received */
 
-  SHA1(c->mychallenge, RSA_size(myself->connection->rsa_key), hash);
+  EVP_DigestInit(&ctx, c->indigest);
+  EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key));
+  EVP_DigestFinal(&ctx, hash, NULL);
 
   /* Convert the hash to a hexadecimal formatted string */
 
-  bin2hex(hash,hash,SHA_DIGEST_LENGTH);
+  bin2hex(hash,hash,c->indigest->md_size);
-  hash[SHA_DIGEST_LENGTH*2] = '\0';
+  hash[c->indigest->md_size*2] = '\0';
 
   /* Send the reply */
 
@@ -360,7 +409,8 @@ cp
 int chal_reply_h(connection_t *c)
 {
   char hishash[MAX_STRING_SIZE];
-  char myhash[SHA_DIGEST_LENGTH];
+  char myhash[EVP_MAX_MD_SIZE];
+  EVP_MD_CTX ctx;
 cp
   if(sscanf(c->buffer, "%*d "MAX_STRING, hishash) != 1)
     {
@@ -370,7 +420,7 @@ cp
 
   /* Check if the length of the hash is all right */
 
-  if(strlen(hishash) != SHA_DIGEST_LENGTH*2)
+  if(strlen(hishash) != c->outdigest->md_size*2)
     {
       syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length"));
       return -1;
@@ -378,15 +428,17 @@ cp
 
   /* Convert the hash to binary format */
 
-  hex2bin(hishash, hishash, SHA_DIGEST_LENGTH);
+  hex2bin(hishash, hishash, c->outdigest->md_size);
 
   /* Calculate the hash from the challenge we sent */
 
-  SHA1(c->hischallenge, RSA_size(c->rsa_key), myhash);
+  EVP_DigestInit(&ctx, c->outdigest);
+  EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key));
+  EVP_DigestFinal(&ctx, myhash, NULL);
 
   /* Verify the incoming hash with the calculated hash */
 
-  if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
+  if(memcmp(hishash, myhash, c->outdigest->md_size))
     {
       syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply"));
       if(debug_lvl >= DEBUG_SCARY_THINGS)

src/protocol_key.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_key.c,v 1.1.4.2 2002/02/11 15:59:18 guus Exp $
+    $Id: protocol_key.c,v 1.1.4.3 2002/02/20 19:25:09 guus Exp $
 */
 
 #include "config.h"
@@ -41,7 +41,7 @@
 #include "connection.h"
 #include "node.h"
 #include "edge.h"
-\
+
 #include "system.h"
 
 int mykeyused = 0;
@@ -245,6 +245,8 @@ cp
       from->cipher = NULL;
     }
 
+  from->maclength = maclength;
+
   if(digest)
     {
       from->digest = EVP_get_digestbynid(digest);
@@ -253,7 +255,6 @@ cp
 	  syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname);
 	  return -1;
 	}
-      from->maclength = maclength;
       if(from->maclength > from->digest->md_size || from->maclength < 0)
 	{
 	  syslog(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname);
@@ -263,7 +264,6 @@ cp
   else
     {
       from->digest = NULL;
-      from->maclength = maclength;
     }
 
   from->compression = compression;