Update Keccak to the round 3 variant announced 2011-01-17

Only change is the padding rule. It 'simplifies' the padding by making
it less flexible and harder to implement efficiently. :(

2 files changed, 4 insertions, 9 deletions

diff --git a/src/hash/keccak/keccak.cpp b/src/hash/keccak/keccak.cpp
index 841c8875d..922167b61 100644
--- a/src/hash/keccak/keccak.cpp
+++ b/src/hash/keccak/keccak.cpp
@@ -104,7 +104,6 @@ void keccak_f_1600(u64bit A[25])
 Keccak_1600::Keccak_1600(size_t output_bits) :
    output_bits(output_bits),
    bitrate(1600 - 2*output_bits),
-   diversifier(static_cast<byte>(output_bits / 8)),
    S(25),
    S_pos(0)
    {
@@ -179,15 +178,12 @@ void Keccak_1600::add_data(const byte input[], size_t length)
 
 void Keccak_1600::final_result(byte output[])
    {
-   const byte padding[4] = { 0x01,
-                             diversifier,
-                             static_cast<byte>(bitrate / 8),
-                             0x01 };
+   MemoryVector<byte> padding(bitrate / 8 - S_pos);
 
-   add_data(padding, sizeof(padding));
+   padding[0] = 0x01;
+   padding[padding.size()-1] |= 0x80;
 
-   if(S_pos)
-      keccak_f_1600(&S[0]);
+   add_data(padding, padding.size());
 
    /*
    * We never have to run the permutation again because we only support
diff --git a/src/hash/keccak/keccak.h b/src/hash/keccak/keccak.h
index 1c6ec3122..17ae632ba 100644
--- a/src/hash/keccak/keccak.h
+++ b/src/hash/keccak/keccak.h
@@ -38,7 +38,6 @@ class BOTAN_DLL Keccak_1600 : public HashFunction
       void final_result(byte out[]);
 
       size_t output_bits, bitrate;
-      byte diversifier;
       SecureVector<u64bit> S;
       size_t S_pos;
    };