Change the BlockCipher interface to support multi-block encryption and

decryption. Currently only used for counter mode. Doesn't offer much
advantage as-is (though might help slightly, in terms of cache effects),
but allows for SIMD implementations to process multiple blocks in parallel
when possible. Particularly thinking here of Serpent; TEA/XTEA also seem
promising in this sense, as is Threefish once that is implemented as a
standalone block cipher.

2 files changed, 41 insertions, 30 deletions

diff --git a/src/block/gost_28147/gost_28147.cpp b/src/block/gost_28147/gost_28147.cpp
index bfd092c56..272f1bcab 100644
--- a/src/block/gost_28147/gost_28147.cpp
+++ b/src/block/gost_28147/gost_28147.cpp
@@ -84,47 +84,58 @@ GOST_28147_89::GOST_28147_89(const GOST_28147_89_Params& param) :
 /*
 * GOST Encryption
 */
-void GOST_28147_89::enc(const byte in[], byte out[]) const
+void GOST_28147_89::encrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1);
-
-   for(size_t i = 0; i != 3; ++i)
+   for(u32bit i = 0; i != blocks; ++i)
       {
-      GOST_2ROUND(N1, N2, 0, 1);
-      GOST_2ROUND(N1, N2, 2, 3);
-      GOST_2ROUND(N1, N2, 4, 5);
-      GOST_2ROUND(N1, N2, 6, 7);
-      }
+      u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1);
 
-   GOST_2ROUND(N1, N2, 7, 6);
-   GOST_2ROUND(N1, N2, 5, 4);
-   GOST_2ROUND(N1, N2, 3, 2);
-   GOST_2ROUND(N1, N2, 1, 0);
+      for(size_t j = 0; j != 3; ++j)
+         {
+         GOST_2ROUND(N1, N2, 0, 1);
+         GOST_2ROUND(N1, N2, 2, 3);
+         GOST_2ROUND(N1, N2, 4, 5);
+         GOST_2ROUND(N1, N2, 6, 7);
+         }
 
-   store_le(out, N2, N1);
+      GOST_2ROUND(N1, N2, 7, 6);
+      GOST_2ROUND(N1, N2, 5, 4);
+      GOST_2ROUND(N1, N2, 3, 2);
+      GOST_2ROUND(N1, N2, 1, 0);
+
+      store_le(out, N2, N1);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
 * GOST Decryption
 */
-void GOST_28147_89::dec(const byte in[], byte out[]) const
+void GOST_28147_89::decrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1);
+   for(u32bit i = 0; i != blocks; ++i)
+      {
+      u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1);
 
-   GOST_2ROUND(N1, N2, 0, 1);
-   GOST_2ROUND(N1, N2, 2, 3);
-   GOST_2ROUND(N1, N2, 4, 5);
-   GOST_2ROUND(N1, N2, 6, 7);
+      GOST_2ROUND(N1, N2, 0, 1);
+      GOST_2ROUND(N1, N2, 2, 3);
+      GOST_2ROUND(N1, N2, 4, 5);
+      GOST_2ROUND(N1, N2, 6, 7);
 
-   for(size_t i = 0; i != 3; ++i)
-      {
-      GOST_2ROUND(N1, N2, 7, 6);
-      GOST_2ROUND(N1, N2, 5, 4);
-      GOST_2ROUND(N1, N2, 3, 2);
-      GOST_2ROUND(N1, N2, 1, 0);
-      }
+      for(size_t i = 0; i != 3; ++i)
+         {
+         GOST_2ROUND(N1, N2, 7, 6);
+         GOST_2ROUND(N1, N2, 5, 4);
+         GOST_2ROUND(N1, N2, 3, 2);
+         GOST_2ROUND(N1, N2, 1, 0);
+         }
 
-   store_le(out, N2, N1);
+      store_le(out, N2, N1);
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
diff --git a/src/block/gost_28147/gost_28147.h b/src/block/gost_28147/gost_28147.h
index 96d24c669..825e106a2 100644
--- a/src/block/gost_28147/gost_28147.h
+++ b/src/block/gost_28147/gost_28147.h
@@ -54,8 +54,8 @@ class BOTAN_DLL GOST_28147_89 : public BlockCipher
       GOST_28147_89(const SecureBuffer<u32bit, 1024>& other_SBOX) :
          BlockCipher(8, 32), SBOX(other_SBOX) {}
 
-      void enc(const byte[], byte[]) const;
-      void dec(const byte[], byte[]) const;
+      void encrypt_n(const byte in[], byte out[], u32bit blocks) const;
+      void decrypt_n(const byte in[], byte out[], u32bit blocks) const;
       void key_schedule(const byte[], u32bit);
 
       SecureBuffer<u32bit, 1024> SBOX;