Merge pull request #60 from emanuele-f/enable_aes

Add AES CBC psk encryption

Makefile.in

@@ -76,7 +76,7 @@ supernode: sn.c $(N2N_LIB) n2n.h Makefile
 	$(CC) $(CFLAGS) sn.c $(N2N_LIB) $(LIBS_SN) -o supernode
 
 benchmark: benchmark.c $(N2N_LIB) n2n_wire.h n2n.h Makefile
-	$(CC) $(CFLAGS) benchmark.c $(N2N_LIB) $(LIBS_SN) -o benchmark
+	$(CC) $(CFLAGS) benchmark.c $(N2N_LIB) $(LIBS_EDGE) -o benchmark
 
 example_edge_embed: example_edge_embed.c $(N2N_LIB) n2n.h
 	$(CC) $(CFLAGS) example_edge_embed.c $(N2N_LIB) $(LIBS_EDGE) -o example_edge_embed

benchmark.c

@@ -70,14 +70,38 @@ uint8_t PKT_CONTENT[]={
 
 /* Prototypes */
 static ssize_t do_encode_packet( uint8_t * pktbuf, size_t bufsize, const n2n_community_t c );
+static void run_transop_benchmark(const char *op_name, n2n_trans_op_t *op_fn, uint8_t *pktbuf, n2n_community_t c);
 
 int main(int argc, char * argv[]) {
   uint8_t pktbuf[N2N_PKT_BUF_SIZE];
-  n2n_trans_op_t transop_null;
+  n2n_community_t c;
+  n2n_trans_op_t transop_null, transop_twofish, transop_aes_cbc;
+  u_char encrypt_pwd[] = "SoMEVer!S$cUREPassWORD";
+
+  memset(c,0,sizeof(N2N_COMMUNITY_SIZE));
+  memcpy(c, "abc123def456", 12);
+
+  /* Init transopts */
+  memset(&transop_null, 0, sizeof(transop_null));
+  transop_null_init(&transop_null);
+  memset(&transop_twofish, 0, sizeof(transop_twofish));
+  transop_twofish_init(&transop_twofish);
+  transop_twofish_setup_psk(&transop_twofish, 0, encrypt_pwd, sizeof(encrypt_pwd)-1);
+  memset(&transop_aes_cbc, 0, sizeof(transop_aes_cbc));
+  transop_aes_init(&transop_aes_cbc);
+  transop_aes_setup_psk(&transop_aes_cbc, 0, encrypt_pwd, sizeof(encrypt_pwd)-1);
+
+  /* Run the tests */
+  run_transop_benchmark("transop_null", &transop_null, pktbuf, c);
+  run_transop_benchmark("transop_twofish", &transop_twofish, pktbuf, c);
+  run_transop_benchmark("transop_aes", &transop_aes_cbc, pktbuf, c);
+
+  return 0;
+}
 
+static void run_transop_benchmark(const char *op_name, n2n_trans_op_t *op_fn, uint8_t *pktbuf, n2n_community_t c) {
   n2n_common_t cmn;
   n2n_PACKET_t pkt;
-  n2n_community_t c;
 
   struct timeval t1;
   struct timeval t2;
@@ -89,18 +113,14 @@ int main(int argc, char * argv[]) {
   ssize_t nw;
   ssize_t tdiff;
 
-  transop_null_init( &transop_null );
-  memset(c,0,sizeof(N2N_COMMUNITY_SIZE));
-
   n=10000;
-  memcpy( c, "abc123def456", 12 );
 
   gettimeofday( &t1, NULL );
   for(i=0; i<n; ++i)
     {
       nw = do_encode_packet( pktbuf, N2N_PKT_BUF_SIZE, c);
 
-      nw += transop_null.fwd( &transop_null,
+      nw += op_fn->fwd( op_fn,
 			      pktbuf+nw, N2N_PKT_BUF_SIZE-nw,
 			      PKT_CONTENT, sizeof(PKT_CONTENT) );
 
@@ -110,7 +130,7 @@ int main(int argc, char * argv[]) {
       decode_common( &cmn, pktbuf, &rem, &idx);
       decode_PACKET( &pkt, &cmn, pktbuf, &rem, &idx );
 
-      if ( 0 == (i%1000) )
+      if ( 0 == (i%(n/10)) )
         {
 	  fprintf(stderr,".");
         }
@@ -119,13 +139,12 @@ int main(int argc, char * argv[]) {
 
   tdiff = ((t2.tv_sec - t1.tv_sec) * 1000000) + (t2.tv_usec - t1.tv_usec);
 
-  fprintf( stderr, "\nrun %u times. (%u -> %u nsec each) %u.%06u -> %u.%06u.\n",
+  fprintf( stderr, "\n[%s] %u times: (%u -> %u nsec each) %u.%06u -> %u.%06u.\n",
+	   op_name,
 	   (unsigned int)i, (unsigned int)tdiff,
 	   (unsigned int)((tdiff *1000)/i),
 	   (uint32_t)t1.tv_sec, (uint32_t)t1.tv_usec,
 	   (uint32_t)t2.tv_sec, (uint32_t)t2.tv_usec );
-
-  return 0;
 }
 
 static ssize_t do_encode_packet( uint8_t * pktbuf, size_t bufsize, const n2n_community_t c )
@@ -154,3 +173,4 @@ static ssize_t do_encode_packet( uint8_t * pktbuf, size_t bufsize, const n2n_com
     
   return idx;
 }
+

edge.c

@@ -136,7 +136,7 @@ static void help() {
 	 "-l <supernode host:port>\n"
 	 "    "
 	 "[-p <local port>] [-M <mtu>] "
-	 "[-r] [-E] [-v] [-t <mgmt port>] [-b] [-h]\n\n");
+	 "[-r] [-E] [-v] [-t <mgmt port>] [-b] [-A] [-h]\n\n");
 
 #ifdef __linux__
   printf("-d <tun device>          | tun device name\n");
@@ -162,6 +162,7 @@ static void help() {
          "                         | eg. -m 01:02:03:04:05:06\n");
   printf("-M <mtu>                 | Specify n2n MTU of edge interface (default %d).\n", DEFAULT_MTU);
   printf("-r                       | Enable packet forwarding through n2n community.\n");
+  printf("-A                       | Set AES CBC as the preferred encryption mode.\n");
   printf("-E                       | Accept multicast MAC addresses (default=drop).\n");
   printf("-v                       | Make more verbose. Repeat as required.\n");
   printf("-t <port>                | Management UDP Port (for multiple edges on a machine).\n");
@@ -268,6 +269,12 @@ static int setOption(int optkey, char *optargument, edge_conf_t *ec, n2n_edge_t
       break;
     }
 
+  case 'A':
+    {
+      eee->preferred_aes = 1;
+      break;
+    }
+
   case 'l': /* supernode-list */
     if(optargument) {
       if(eee->sn_num < N2N_EDGE_NUM_SUPERNODES) {
@@ -357,7 +364,7 @@ static int loadFromCLI(int argc, char *argv[], edge_conf_t *ec, n2n_edge_t *eee)
   u_char c;
 
   while((c = getopt_long(argc, argv,
-			 "K:k:a:bc:Eu:g:m:M:s:d:l:p:fvhrt:",
+			 "K:k:a:bc:Eu:g:m:M:s:d:l:p:fvhrAt:",
 			 long_options, NULL)) != '?') {
     if(c == 255) break;
     setOption(c, optarg, ec, eee);
@@ -665,8 +672,12 @@ int main(int argc, char* argv[]) {
     traceEvent(TRACE_NORMAL, "Binding to local port %d", (signed int)ec.local_port);
 
   if(ec.encrypt_key) {
-    if(edge_init_twofish(&eee, (uint8_t *)(ec.encrypt_key), strlen(ec.encrypt_key)) < 0) {
+    if(edge_init_aes_psk(&eee, (uint8_t *)(ec.encrypt_key), strlen(ec.encrypt_key)) < 0) {
-      fprintf(stderr, "Error: twofish setup failed.\n");
+      fprintf(stderr, "Error: AES PSK setup failed.\n");
+      return(-1);
+    }
+    if(edge_init_twofish_psk(&eee, (uint8_t *)(ec.encrypt_key), strlen(ec.encrypt_key)) < 0) {
+      fprintf(stderr, "Error: twofish PSK setup failed.\n");
       return(-1);
     }
   } else if(strlen(eee.keyschedule) > 0) {

edge_utils.c

@@ -75,6 +75,7 @@ int edge_init(n2n_edge_t * eee) {
   eee->tx_transop_idx = N2N_TRANSOP_NULL_IDX; /* No guarantee the others have been setup */
 
   eee->daemon = 1;    /* By default run in daemon mode. */
+  eee->preferred_aes = 0; /* Disable AES by default (for compatibility) */
   eee->re_resolve_supernode_ip = 0;
   /* keyschedule set to NULLs by memset */
   /* community_name set to NULLs by memset */
@@ -644,38 +645,66 @@ const char * supernode_ip(const n2n_edge_t * eee) {
 
 /* ************************************** */
 
-int edge_init_twofish(n2n_edge_t * eee, uint8_t *encrypt_pwd,
+int edge_init_twofish_psk(n2n_edge_t * eee, uint8_t *encrypt_pwd,
 		      uint32_t encrypt_pwd_len) {
-  return transop_twofish_setup(&(eee->transop[N2N_TRANSOP_TF_IDX]),
+  return transop_twofish_setup_psk(&(eee->transop[N2N_TRANSOP_TF_IDX]),
 			       0, encrypt_pwd, encrypt_pwd_len);
 }
 
 /* ************************************** */
 
-/** Called periodically to roll keys and do any periodic maintenance in the
+int edge_init_aes_psk(n2n_edge_t * eee, uint8_t *encrypt_pwd,
- *  tranform operations state machines. */
+		      uint32_t encrypt_pwd_len) {
-static int n2n_tick_transop(n2n_edge_t * eee, time_t now)
+  return transop_aes_setup_psk(&(eee->transop[N2N_TRANSOP_AESCBC_IDX]),
-{
+			       0, encrypt_pwd, encrypt_pwd_len);
-  n2n_tostat_t tst;
+}
-  size_t trop = eee->tx_transop_idx;
+
+/* ************************************** */
+
+static n2n_tostat_t n2n_tick_aes(n2n_edge_t * eee, time_t now, size_t *trop) {
+  n2n_tostat_t tst = (eee->transop[N2N_TRANSOP_AESCBC_IDX].tick)(&(eee->transop[N2N_TRANSOP_AESCBC_IDX]), now);
 
-  /* Tests are done in order that most preferred transform is last and causes
-   * tx_transop_idx to be left at most preferred valid transform. */
-  tst = (eee->transop[N2N_TRANSOP_NULL_IDX].tick)(&(eee->transop[N2N_TRANSOP_NULL_IDX]), now);
-  tst = (eee->transop[N2N_TRANSOP_AESCBC_IDX].tick)(&(eee->transop[N2N_TRANSOP_AESCBC_IDX]), now);
   if(tst.can_tx)
     {
       traceEvent(TRACE_DEBUG, "can_tx AESCBC (idx=%u)", (unsigned int)N2N_TRANSOP_AESCBC_IDX);
-      trop = N2N_TRANSOP_AESCBC_IDX;
+      *trop = N2N_TRANSOP_AESCBC_IDX;
     }
 
-  tst = (eee->transop[N2N_TRANSOP_TF_IDX].tick)(&(eee->transop[N2N_TRANSOP_TF_IDX]), now);
+  return tst;
+}
+
+/* ************************************** */
+static n2n_tostat_t n2n_tick_twofish(n2n_edge_t * eee, time_t now, size_t *trop) {
+  n2n_tostat_t tst = (eee->transop[N2N_TRANSOP_TF_IDX].tick)(&(eee->transop[N2N_TRANSOP_TF_IDX]), now);
   if(tst.can_tx)
     {
       traceEvent(TRACE_DEBUG, "can_tx TF (idx=%u)", (unsigned int)N2N_TRANSOP_TF_IDX);
-      trop = N2N_TRANSOP_TF_IDX;
+      *trop = N2N_TRANSOP_TF_IDX;
     }
 
+  return tst;
+}
+
+/* ************************************** */
+
+/** Called periodically to roll keys and do any periodic maintenance in the
+ *  tranform operations state machines. */
+static int n2n_tick_transop(n2n_edge_t * eee, time_t now)
+{
+  size_t trop = eee->tx_transop_idx;
+
+  /* Tests are done in order that most preferred transform is last and causes
+   * tx_transop_idx to be left at most preferred valid transform. */
+  (eee->transop[N2N_TRANSOP_NULL_IDX].tick)(&(eee->transop[N2N_TRANSOP_NULL_IDX]), now);
+
+  if(eee->preferred_aes) {
+    n2n_tick_twofish(eee, now, &trop);
+    n2n_tick_aes(eee, now, &trop);
+  } else {
+    n2n_tick_aes(eee, now, &trop);
+    n2n_tick_twofish(eee, now, &trop);
+  }
+
   if(trop != eee->tx_transop_idx)
     {
       eee->tx_transop_idx = trop;
@@ -1688,8 +1717,10 @@ int quick_edge_init(char *device_name, char *community_name,
 		 device_mac, DEFAULT_MTU) < 0)
     return(-1);
 
-  if(edge_init_twofish(&eee, (uint8_t *)encrypt_key, strlen(encrypt_key)) < 0)
+  if(edge_init_aes_psk(&eee, (uint8_t *)encrypt_key, strlen(encrypt_key)) < 0)
-    return(-2);  
+    return(-2);
+  if(edge_init_twofish_psk(&eee, (uint8_t *)encrypt_key, strlen(encrypt_key)) < 0)
+    return(-2);
 
   snprintf((char*)eee.community_name, sizeof(eee.community_name), "%s", community_name);
   supernode2addr(&(eee.supernode), supernode_ip_address_port);

n2n.h

@@ -186,6 +186,7 @@ typedef char n2n_sn_name_t[N2N_EDGE_SN_HOST_SIZE];
 
 struct n2n_edge {
   int                 daemon;                 /**< Non-zero if edge should detach and run in the background. */
+  int                 preferred_aes;          /**< Non-zero if AES is the preferred encryption meothd. */
   uint8_t             re_resolve_supernode_ip;
 
   n2n_sock_t          supernode;
@@ -337,7 +338,9 @@ void set_peer_operational(n2n_edge_t * eee,
 			  const n2n_mac_t mac,
 			  const n2n_sock_t * peer);
 const char * supernode_ip(const n2n_edge_t * eee);
-int edge_init_twofish(n2n_edge_t * eee, uint8_t *encrypt_pwd,
+int edge_init_twofish_psk(n2n_edge_t * eee, uint8_t *encrypt_pwd,
+		      uint32_t encrypt_pwd_len);
+int edge_init_aes_psk(n2n_edge_t * eee, uint8_t *encrypt_pwd,
 		      uint32_t encrypt_pwd_len);
 int run_edge_loop(n2n_edge_t * eee, int *keep_running);
 void edge_term(n2n_edge_t * eee);

n2n_transforms.h

@@ -78,7 +78,12 @@ struct n2n_trans_op {
 };
 
 /* Setup a single twofish SA for single-key operation. */
-int transop_twofish_setup( n2n_trans_op_t * ttt, 
+int transop_twofish_setup_psk( n2n_trans_op_t * ttt, 
+                           n2n_sa_t sa_num,
+                           uint8_t * encrypt_pwd, 
+                           uint32_t encrypt_pwd_len );
+/* Setup a single AES SA for single-key operation. */
+int transop_aes_setup_psk( n2n_trans_op_t * ttt, 
                            n2n_sa_t sa_num,
                            uint8_t * encrypt_pwd, 
                            uint32_t encrypt_pwd_len );

transform_aes.c

@@ -339,6 +339,41 @@ static int transop_decode_aes( n2n_trans_op_t * arg,
     return len;
 }
 
+/*
+ * priv: pointer to transform state
+ * keybuf: buffer holding the key
+ * pstat: length of keybuf
+ */
+static void add_aes_key(transop_aes_t *priv, uint8_t *keybuf, ssize_t pstat) {
+    /* pstat is number of bytes read into keybuf. */
+    sa_aes_t * sa = &(priv->sa[priv->num_sa]);
+    size_t aes_keysize_bytes;
+    size_t aes_keysize_bits;
+
+    /* Clear out any old possibly longer key matter. */
+    memset( &(sa->enc_key), 0, sizeof(AES_KEY) );
+    memset( &(sa->dec_key), 0, sizeof(AES_KEY) );
+
+    memset( &(sa->enc_ivec), 0, sizeof(N2N_AES_IVEC_SIZE) );
+    memset( &(sa->dec_ivec), 0, sizeof(N2N_AES_IVEC_SIZE) );
+
+    aes_keysize_bytes = aes_best_keysize(pstat);
+    aes_keysize_bits = 8 * aes_keysize_bytes;
+
+    /* Use N2N_MAX_KEYSIZE because the AES key needs to be of fixed
+     * size. If fewer bits specified then the rest will be
+     * zeroes. AES acceptable key sizes are 128, 192 and 256
+     * bits. */
+    AES_set_encrypt_key( keybuf, aes_keysize_bits, &(sa->enc_key));
+    AES_set_decrypt_key( keybuf, aes_keysize_bits, &(sa->dec_key));
+    /* Leave ivecs set to all zeroes */
+    
+    traceEvent( TRACE_DEBUG, "transop_addspec_aes sa_id=%u, %u bits data=%s.\n",
+                priv->sa[priv->num_sa].sa_id, aes_keysize_bits, keybuf);
+    
+    ++(priv->num_sa);
+}
+
 static int transop_addspec_aes( n2n_trans_op_t * arg, const n2n_cipherspec_t * cspec )
 {
     int retval = 1;
@@ -369,33 +404,7 @@ static int transop_addspec_aes( n2n_trans_op_t * arg, const n2n_cipherspec_t * c
             pstat = n2n_parse_hex( keybuf, N2N_MAX_KEYSIZE, sep+1, s );
             if ( pstat > 0 )
             {
-                /* pstat is number of bytes read into keybuf. */
+                add_aes_key(priv, keybuf, pstat);
-                sa_aes_t * sa = &(priv->sa[priv->num_sa]);
-                size_t aes_keysize_bytes;
-                size_t aes_keysize_bits;
-
-                /* Clear out any old possibly longer key matter. */
-                memset( &(sa->enc_key), 0, sizeof(AES_KEY) );
-                memset( &(sa->dec_key), 0, sizeof(AES_KEY) );
-
-                memset( &(sa->enc_ivec), 0, sizeof(N2N_AES_IVEC_SIZE) );
-                memset( &(sa->dec_ivec), 0, sizeof(N2N_AES_IVEC_SIZE) );
-
-                aes_keysize_bytes = aes_best_keysize(pstat);
-                aes_keysize_bits = 8 * aes_keysize_bytes;
-
-                /* Use N2N_MAX_KEYSIZE because the AES key needs to be of fixed
-                 * size. If fewer bits specified then the rest will be
-                 * zeroes. AES acceptable key sizes are 128, 192 and 256
-                 * bits. */
-                AES_set_encrypt_key( keybuf, aes_keysize_bits, &(sa->enc_key));
-                AES_set_decrypt_key( keybuf, aes_keysize_bits, &(sa->dec_key));
-                /* Leave ivecs set to all zeroes */
-                
-                traceEvent( TRACE_DEBUG, "transop_addspec_aes sa_id=%u, %u bits data=%s.\n",
-                            priv->sa[priv->num_sa].sa_id, aes_keysize_bits, sep+1);
-                
-                ++(priv->num_sa);
                 retval = 0;
             }
         }
@@ -510,6 +519,31 @@ int transop_aes_init( n2n_trans_op_t * ttt )
     return retval;
 }
 
+/* Setup AES in pre-shared key mode */
+int transop_aes_setup_psk(n2n_trans_op_t *ttt,
+                           n2n_sa_t sa_num,
+                           uint8_t *encrypt_pwd,
+                           uint32_t encrypt_pwd_len) {
+    int retval = 1;
+    transop_aes_t *priv = (transop_aes_t *)ttt->priv;
+
+    if(ttt->priv) {
+        sa_aes_t *sa;
+        priv->num_sa=0;
+        priv->tx_sa=0;
+        sa = &(priv->sa[priv->tx_sa]);
+        sa->sa_id=sa_num;
+        sa->spec.valid_until = 0x7fffffff;
+
+        /* This is a preshared key setup. Both Tx and Rx are using the same security association. */
+        add_aes_key(priv, encrypt_pwd, encrypt_pwd_len);
+        retval = 0;
+    } else
+        traceEvent(TRACE_ERROR, "AES priv is not allocated");
+
+    return retval;
+}
+
 #else /* #if defined(N2N_HAVE_AES) */
 
 struct transop_aes
@@ -606,5 +640,13 @@ int transop_aes_init( n2n_trans_op_t * ttt )
     return retval;
 }
 
+
+int transop_aes_setup_psk(n2n_trans_op_t *ttt,
+                           n2n_sa_t sa_num,
+                           uint8_t *encrypt_pwd,
+                           uint32_t encrypt_pwd_len) {
+    return 0;
+}
+
 #endif /* #if defined(N2N_HAVE_AES) */
 

transform_tf.c

@@ -384,73 +384,34 @@ static n2n_tostat_t transop_tick_twofish( n2n_trans_op_t * arg, time_t now )
   return r;
 }
 
-
+int transop_twofish_setup_psk( n2n_trans_op_t * ttt, 
-int transop_twofish_setup( n2n_trans_op_t * ttt, 
                            n2n_sa_t sa_num,
                            uint8_t * encrypt_pwd, 
                            uint32_t encrypt_pwd_len )
 {
   int retval = 1;
-  transop_tf_t * priv = NULL;
+  transop_tf_t * priv = (transop_tf_t *)ttt->priv;
-
-  if ( ttt->priv )
-    {
-      transop_deinit_twofish( ttt );
-    }
 
-  memset( ttt, 0, sizeof( n2n_trans_op_t ) );
+  if(priv) {
+    sa_twofish_t *sa;
 
-  priv = (transop_tf_t *) malloc( sizeof(transop_tf_t) );
+    priv->num_sa=1;         /* There is one SA in the array. */
+    priv->tx_sa=0;
+    sa = &(priv->sa[priv->tx_sa]);
+    sa->sa_id=sa_num;
+    sa->spec.valid_until = 0x7fffffff;
 
-  if ( NULL != priv )
+    /* This is a preshared key setup. Both Tx and Rx are using the same security association. */
-    {
-      size_t i;
-      sa_twofish_t * sa=NULL;
 
-      /* install the private structure. */
+    sa->enc_tf = TwoFishInit(encrypt_pwd, encrypt_pwd_len);
-      ttt->priv = priv;
+    sa->dec_tf = TwoFishInit(encrypt_pwd, encrypt_pwd_len);
 
-      for(i=0; i<N2N_TWOFISH_NUM_SA; ++i)
+    if ( (sa->enc_tf) && (sa->dec_tf) )
-        {
+      retval = 0;
-	  sa = &(priv->sa[i]);
+    else
-	  sa->sa_id=0;
+      traceEvent( TRACE_ERROR, "transop_twofish_setup_psk" );
-	  memset( &(sa->spec), 0, sizeof(n2n_cipherspec_t) );
+  } else
-	  sa->enc_tf=NULL;
+    traceEvent( TRACE_ERROR, "twofish priv is not allocated" );
-	  sa->dec_tf=NULL;
-        }
-
-      priv->num_sa=1;         /* There is one SA in the array. */
-      priv->tx_sa=0;
-      sa = &(priv->sa[priv->tx_sa]);
-      sa->sa_id=sa_num;
-      sa->spec.valid_until = 0x7fffffff;
-
-      /* This is a preshared key setup. Both Tx and Rx are using the same security association. */
-
-      sa->enc_tf = TwoFishInit(encrypt_pwd, encrypt_pwd_len);
-      sa->dec_tf = TwoFishInit(encrypt_pwd, encrypt_pwd_len);
-
-      if ( (sa->enc_tf) && (sa->dec_tf) )
-        {
-	  ttt->transform_id = N2N_TRANSFORM_ID_TWOFISH;
-	  ttt->deinit = transop_deinit_twofish;
-	  ttt->addspec = transop_addspec_twofish;
-	  ttt->tick = transop_tick_twofish; /* chooses a new tx_sa */
-	  ttt->fwd = transop_encode_twofish;
-	  ttt->rev = transop_decode_twofish;
-                
-	  retval = 0;
-        }
-      else
-        {
-	  traceEvent( TRACE_ERROR, "TwoFishInit failed" );
-        }
-    }
-  else
-    {
-      memset( ttt, 0, sizeof(n2n_trans_op_t) );
-      traceEvent( TRACE_ERROR, "Failed to allocate priv for twofish" );
-    }
 
   return retval;
 }