Fixed CTR mode rekey. Fixsed IV Included CTR mode encryption/

 	decryption in packet engine.

diff --git a/CHANGES.TOOLKIT b/CHANGES.TOOLKIT
index 64cfe8c2232665660019d7a08b9512c96213a24f..65844e8f1bbf7992ffc82b3bddeb81f404c8f231 100644 (file)
--- a/CHANGES.TOOLKIT
+++ b/CHANGES.TOOLKIT
@@ -1,3 +1,10 @@
+Mon Nov  5 22:24:25 EET 2007  Pekka Riikonen <priikone@silcnet.org>
+
+       * Fixed CTR mode rekey.  Affected file is lib/silcske/silcske.c.
+
+       * Rewrote the IV Included CTR mode encryption/decryption in
+         packet engine.  Affected file is lib/silccore/silcpacket.c.
+
 Sun Aug 26 12:28:49 EEST 2007  Pekka Riikonen <priikone@silcnet.org>
 
         * Fixed TIMEOUT handling in user info resolving during JOINing,

diff --git a/lib/silccore/silcpacket.c b/lib/silccore/silcpacket.c
index c8fd4b122280961941e36f289c525e0543f53547..17aee8d46fa27432a43a8bb1c7f587b5b57ea9a6 100644 (file)
--- a/lib/silccore/silcpacket.c
+++ b/lib/silccore/silcpacket.c
@@ -786,6 +786,8 @@ SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
     return NULL;
   }
 
+  SILC_LOG_DEBUG(("Created packet stream %p", ps));
+
   return ps;
 }
 
@@ -888,6 +890,8 @@ void silc_packet_stream_destroy(SilcPacketStream stream)
   if (silc_atomic_sub_int8(&stream->refcnt, 1) > 0) {
     stream->destroyed = TRUE;
 
+    SILC_LOG_DEBUG(("Marking packet stream %p destroyed", stream));
+
     /* Close the underlaying stream */
     if (!stream->udp && stream->stream)
       silc_stream_close(stream->stream);
@@ -1468,14 +1472,6 @@ static inline void silc_packet_send_ctr_increment(SilcPacketStream stream,
   unsigned char *iv = silc_cipher_get_iv(cipher);
   SilcUInt32 pc1, pc2;
 
-  /* Increment 64-bit packet counter */
-  SILC_GET32_MSB(pc1, iv + 4);
-  SILC_GET32_MSB(pc2, iv + 8);
-  if (++pc2 == 0)
-    ++pc1;
-  SILC_PUT32_MSB(pc1, iv + 4);
-  SILC_PUT32_MSB(pc2, iv + 8);
-
   /* Reset block counter */
   memset(iv + 12, 0, 4);
 
@@ -1486,11 +1482,24 @@ static inline void silc_packet_send_ctr_increment(SilcPacketStream stream,
     ret_iv[1] = ret_iv[0] + iv[4];
     ret_iv[2] = ret_iv[0] ^ ret_iv[1];
     ret_iv[3] = ret_iv[0] + ret_iv[2];
-    SILC_PUT32_MSB(pc2, ret_iv + 4);
+
+    /* Increment 32-bit packet counter */
+    SILC_GET32_MSB(pc1, iv + 8);
+    pc1++;
+    SILC_PUT32_MSB(pc1, ret_iv + 4);
+
     SILC_LOG_HEXDUMP(("IV"), ret_iv, 8);
 
     /* Set new nonce to counter block */
-    memcpy(iv + 4, ret_iv, 4);
+    memcpy(iv + 4, ret_iv, 8);
+  } else {
+    /* Increment 64-bit packet counter */
+    SILC_GET32_MSB(pc1, iv + 4);
+    SILC_GET32_MSB(pc2, iv + 8);
+    if (++pc2 == 0)
+      ++pc1;
+    SILC_PUT32_MSB(pc1, iv + 4);
+    SILC_PUT32_MSB(pc2, iv + 8);
   }
 
   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
@@ -1605,6 +1614,12 @@ static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
 
   silc_mutex_lock(stream->lock);
 
+  if (silc_unlikely(stream->destroyed)) {
+    SILC_LOG_DEBUG(("Stream %p is destroyed, cannot send packet", stream));
+    silc_mutex_unlock(stream->lock);
+    return FALSE;
+  }
+
   /* Get packet pointer from the outgoing buffer */
   if (silc_unlikely(!silc_packet_send_prepare(stream, truelen + padlen + ivlen
                                              + psnlen, hmac, &packet))) {

diff --git a/lib/silccore/silcpacket.h b/lib/silccore/silcpacket.h
index f8f41cb8a84ec14dc08f32d622dbfda0a20c3758..3d4ca10de77f4ad3089684fb93fd9d0cb1826cb0 100644 (file)
--- a/lib/silccore/silcpacket.h
+++ b/lib/silccore/silcpacket.h
@@ -402,6 +402,12 @@ const char *silc_packet_error_string(SilcPacketError error);
  *    Returns list of packet streams added to the packet engine.  The caller
  *    must free the list with silc_packet_engine_free_streams_list.
  *
+ * NOTES
+ *
+ *    This function may also return disconnected and destroyed streams.  The
+ *    caller should use silc_packet_stream_is_valid to check if the stream
+ *    is valid.
+ *
  ***/
 SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
 

diff --git a/lib/silcske/silcske.c b/lib/silcske/silcske.c
index 02d0961cfe9c85f1ae8f479cdbaf98496703af92..6583562882a527511507da098aab92db0367338d 100644 (file)
--- a/lib/silcske/silcske.c
+++ b/lib/silcske/silcske.c
@@ -1881,7 +1881,8 @@ SILC_FSM_STATE(silc_ske_st_initiator_failure)
   SilcSKE ske = fsm_context;
   SilcUInt32 error = SILC_SKE_STATUS_ERROR;
 
-  if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
+  if (ske->packet && ske->packet->type == SILC_PACKET_FAILURE &&
+      silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
     ske->status = error;
     silc_packet_free(ske->packet);
@@ -2470,7 +2471,8 @@ SILC_FSM_STATE(silc_ske_st_responder_failure)
 
   SILC_LOG_DEBUG(("Key exchange protocol failed"));
 
-  if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
+  if (ske->packet && ske->packet->type == SILC_PACKET_FAILURE &&
+      silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
     ske->status = error;
     silc_packet_free(ske->packet);
@@ -3416,6 +3418,12 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
       return FALSE;
   }
 
+  /* Allocate hash */
+  if (ret_hash) {
+    if (!silc_hash_alloc(silc_hash_get_name(prop->hash), ret_hash))
+      return FALSE;
+  }
+
   /* Set key material */
   memset(iv, 0, sizeof(iv));
   if (ske->responder) {
@@ -3424,10 +3432,22 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, TRUE);
 
       if (silc_cipher_get_mode(*ret_send_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->receive_iv, iv_included ? 4 : 8);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->receive_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       }
+
         silc_cipher_set_iv(*ret_send_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_send_key, keymat->receive_iv);
       }
     }
@@ -3436,10 +3456,22 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, FALSE);
 
       if (silc_cipher_get_mode(*ret_receive_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->send_iv, iv_included ? 4 : 8);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->send_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       }
+
         silc_cipher_set_iv(*ret_receive_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_receive_key, keymat->send_iv);
       }
     }
@@ -3455,10 +3487,22 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, TRUE);
 
       if (silc_cipher_get_mode(*ret_send_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->send_iv, iv_included ? 4 : 8);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->send_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       }
+
        silc_cipher_set_iv(*ret_send_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_send_key, keymat->send_iv);
       }
     }
@@ -3467,10 +3511,23 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, FALSE);
 
       if (silc_cipher_get_mode(*ret_receive_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->receive_iv, iv_included ? 4 : 8);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV.  If IV Included flag was negotiated we only set the
+            truncated hash value. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->receive_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       }
+
        silc_cipher_set_iv(*ret_receive_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_receive_key, keymat->receive_iv);
       }
     }
@@ -3482,12 +3539,6 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                        keymat->hmac_key_len);
   }
 
-  /* Allocate hash */
-  if (ret_hash) {
-    if (!silc_hash_alloc(silc_hash_get_name(prop->hash), ret_hash))
-      return FALSE;
-  }
-
   return TRUE;
 }