1 files changed, 12 insertions, 8 deletions
diff --git a/src/hash/keccak/keccak.cpp b/src/hash/keccak/keccak.cpp
index 4e5d3744f..9ee4d2363 100644
--- a/src/hash/keccak/keccak.cpp
+++ b/src/hash/keccak/keccak.cpp
@@ -139,14 +139,18 @@ void Keccak_1600::add_data(const byte input[], size_t length)
 
    while(length)
       {
-      const size_t consumed = std::min(length, bitrate / 8 - S_pos);
-      xor_buf(reinterpret_cast<byte*>(&S[0]) + S_pos,
-              input,
-              consumed);
-
-      input += consumed;
-      length -= consumed;
-      S_pos += consumed;
+      size_t to_take = std::min(length, bitrate / 8 - S_pos);
+
+      length -= to_take;
+
+      while(to_take)
+         {
+         S[S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (S_pos % 8));
+
+         ++S_pos;
+         ++input;
+         --to_take;
+         }
 
       if(S_pos == bitrate / 8)
          {