Add proper SHA-3

Kind of a copy and paste of Keccak, but only a single copy of the
permutation at least. Keccak depends on SHA-3 instead of the reverse,
so that SHA-3 can be enabled without also bringing in an unapproved
hash function.

Updates newhope code and removes API function newhope_hash which was
an unofficial SHA-3-256.

3 files changed, 11 insertions, 24 deletions

diff --git a/src/lib/pubkey/newhope/info.txt b/src/lib/pubkey/newhope/info.txt
index 8019b6a7c..08b68fc7a 100644
--- a/src/lib/pubkey/newhope/info.txt
+++ b/src/lib/pubkey/newhope/info.txt
@@ -1,5 +1,5 @@
 define NEWHOPE 20160829
 
 <requires>
-keccak
+sha3
 </requires>
diff --git a/src/lib/pubkey/newhope/newhope.cpp b/src/lib/pubkey/newhope/newhope.cpp
index 8436457b4..25168cc58 100644
--- a/src/lib/pubkey/newhope/newhope.cpp
+++ b/src/lib/pubkey/newhope/newhope.cpp
@@ -10,7 +10,7 @@
 */
 
 #include <botan/newhope.h>
-#include <botan/keccak.h>
+#include <botan/sha3.h>
 #include <botan/loadstor.h>
 
 namespace Botan {
@@ -445,7 +445,7 @@ void keccak_absorb(uint64_t *s,
     for (i = 0; i < r / 8; ++i)
        s[i] ^= load_le<u64bit>(m, i);
 
-    Keccak_1600::permute(s);
+    SHA_3::permute(s);
     mlen -= r;
     m += r;
   }
@@ -465,7 +465,7 @@ inline void keccak_squeezeblocks(uint8_t *h, size_t nblocks,
 {
   while(nblocks > 0)
      {
-     Keccak_1600::permute(s);
+     SHA_3::permute(s);
 
      copy_out_le(h, r, s);
 
@@ -511,24 +511,18 @@ void gen_a(poly *a, const uint8_t *seed)
   }
 }
 
-}
-
-// API FUNCTIONS
-
 void newhope_hash(uint8_t *output, const uint8_t *input, size_t inputByteLen)
-{
-const size_t SHA3_256_RATE = 136;
+   {
+   SHA_3_256 sha3;
 
-  uint64_t s[25];
-  uint8_t t[SHA3_256_RATE];
-  int i;
+   sha3.update(input, inputByteLen);
+   sha3.final(output);
+}
 
-  keccak_absorb(s, SHA3_256_RATE, input, inputByteLen, 0x06);
-  keccak_squeezeblocks(t, 1, s, SHA3_256_RATE);
-  for(i=0;i<32;i++)
-    output[i] = t[i];
 }
 
+// API FUNCTIONS
+
 void newhope_keygen(uint8_t *send, poly *sk, RandomNumberGenerator& rng)
 {
   poly a, e, r, pk;
diff --git a/src/lib/pubkey/newhope/newhope.h b/src/lib/pubkey/newhope/newhope.h
index 794f0750f..875c6e092 100644
--- a/src/lib/pubkey/newhope/newhope.h
+++ b/src/lib/pubkey/newhope/newhope.h
@@ -32,13 +32,6 @@ void BOTAN_DLL newhope_keygen(uint8_t *send, newhope_poly *sk, RandomNumberGener
 void BOTAN_DLL newhope_sharedb(uint8_t *sharedkey, uint8_t *send, const uint8_t *received, RandomNumberGenerator& rng);
 void BOTAN_DLL newhope_shareda(uint8_t *sharedkey, const newhope_poly *ska, const uint8_t *received);
 
-
-/*
-* This is just exposed for testing
-*/
-void BOTAN_DLL newhope_hash(uint8_t *output, const uint8_t *input, size_t inputByteLen);
-
-
 }
 
 #endif