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, 66 insertions, 54 deletions

diff --git a/src/block/seed/seed.cpp b/src/block/seed/seed.cpp
index b06a7cd77..378be16e4 100644
--- a/src/block/seed/seed.cpp
+++ b/src/block/seed/seed.cpp
@@ -22,69 +22,81 @@ u32bit SEED::G_FUNC::operator()(u32bit X) const
 /*
 * SEED Encryption
 */
-void SEED::enc(const byte in[], byte out[]) const
+void SEED::encrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   u32bit B0 = load_be<u32bit>(in, 0);
-   u32bit B1 = load_be<u32bit>(in, 1);
-   u32bit B2 = load_be<u32bit>(in, 2);
-   u32bit B3 = load_be<u32bit>(in, 3);
-
-   G_FUNC G;
-
-   for(u32bit j = 0; j != 16; j += 2)
+   for(u32bit i = 0; i != blocks; ++i)
       {
-      u32bit T0, T1;
-
-      T0 = B2 ^ K[2*j];
-      T1 = G(B2 ^ B3 ^ K[2*j+1]);
-      T0 = G(T1 + T0);
-      T1 = G(T1 + T0);
-      B1 ^= T1;
-      B0 ^= T0 + T1;
-
-      T0 = B0 ^ K[2*j+2];
-      T1 = G(B0 ^ B1 ^ K[2*j+3]);
-      T0 = G(T1 + T0);
-      T1 = G(T1 + T0);
-      B3 ^= T1;
-      B2 ^= T0 + T1;
+      u32bit B0 = load_be<u32bit>(in, 0);
+      u32bit B1 = load_be<u32bit>(in, 1);
+      u32bit B2 = load_be<u32bit>(in, 2);
+      u32bit B3 = load_be<u32bit>(in, 3);
+
+      G_FUNC G;
+
+      for(u32bit j = 0; j != 16; j += 2)
+         {
+         u32bit T0, T1;
+
+         T0 = B2 ^ K[2*j];
+         T1 = G(B2 ^ B3 ^ K[2*j+1]);
+         T0 = G(T1 + T0);
+         T1 = G(T1 + T0);
+         B1 ^= T1;
+         B0 ^= T0 + T1;
+
+         T0 = B0 ^ K[2*j+2];
+         T1 = G(B0 ^ B1 ^ K[2*j+3]);
+         T0 = G(T1 + T0);
+         T1 = G(T1 + T0);
+         B3 ^= T1;
+         B2 ^= T0 + T1;
+         }
+
+      store_be(out, B2, B3, B0, B1);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
       }
-
-   store_be(out, B2, B3, B0, B1);
    }
 
 /*
 * SEED Decryption
 */
-void SEED::dec(const byte in[], byte out[]) const
+void SEED::decrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   u32bit B0 = load_be<u32bit>(in, 0);
-   u32bit B1 = load_be<u32bit>(in, 1);
-   u32bit B2 = load_be<u32bit>(in, 2);
-   u32bit B3 = load_be<u32bit>(in, 3);
-
-   G_FUNC G;
-
-   for(u32bit j = 0; j != 16; j += 2)
+   for(u32bit i = 0; i != blocks; ++i)
       {
-      u32bit T0, T1;
-
-      T0 = B2 ^ K[30-2*j];
-      T1 = G(B2 ^ B3 ^ K[31-2*j]);
-      T0 = G(T1 + T0);
-      T1 = G(T1 + T0);
-      B1 ^= T1;
-      B0 ^= T0 + T1;
-
-      T0 = B0 ^ K[28-2*j];
-      T1 = G(B0 ^ B1 ^ K[29-2*j]);
-      T0 = G(T1 + T0);
-      T1 = G(T1 + T0);
-      B3 ^= T1;
-      B2 ^= T0 + T1;
+      u32bit B0 = load_be<u32bit>(in, 0);
+      u32bit B1 = load_be<u32bit>(in, 1);
+      u32bit B2 = load_be<u32bit>(in, 2);
+      u32bit B3 = load_be<u32bit>(in, 3);
+
+      G_FUNC G;
+
+      for(u32bit j = 0; j != 16; j += 2)
+         {
+         u32bit T0, T1;
+
+         T0 = B2 ^ K[30-2*j];
+         T1 = G(B2 ^ B3 ^ K[31-2*j]);
+         T0 = G(T1 + T0);
+         T1 = G(T1 + T0);
+         B1 ^= T1;
+         B0 ^= T0 + T1;
+
+         T0 = B0 ^ K[28-2*j];
+         T1 = G(B0 ^ B1 ^ K[29-2*j]);
+         T0 = G(T1 + T0);
+         T1 = G(T1 + T0);
+         B3 ^= T1;
+         B2 ^= T0 + T1;
+         }
+
+      store_be(out, B2, B3, B0, B1);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
       }
-
-   store_be(out, B2, B3, B0, B1);
    }
 
 /*
diff --git a/src/block/seed/seed.h b/src/block/seed/seed.h
index 54c25d580..0c9c2c8af 100644
--- a/src/block/seed/seed.h
+++ b/src/block/seed/seed.h
@@ -23,8 +23,8 @@ class BOTAN_DLL SEED : public BlockCipher
       BlockCipher* clone() const { return new SEED; }
       SEED() : BlockCipher(16, 16) {}
    private:
-      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);
 
       class G_FUNC