Fixed CTR rekey. Rewrote IV Included CTR mode encryption/decryption

[silc.git] / lib / silccore / silcpacket.c

diff --git a/lib/silccore/silcpacket.c b/lib/silccore/silcpacket.c
index d03f0d8526afe25af61c55af203c050631f2c060..bea6357939731b0db4ba92ed16cda2cab5e83e9d 100644 (file)
--- a/lib/silccore/silcpacket.c
+++ b/lib/silccore/silcpacket.c
@@ -1471,14 +1471,6 @@ 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);
 
@@ -1489,11 +1481,24 @@ 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);