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, 44 insertions, 32 deletions

diff --git a/src/block/blowfish/blowfish.cpp b/src/block/blowfish/blowfish.cpp
index b0599d6c5..312603c3a 100644
--- a/src/block/blowfish/blowfish.cpp
+++ b/src/block/blowfish/blowfish.cpp
@@ -1,6 +1,6 @@
 /*
 * Blowfish
-* (C) 1999-2007 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
@@ -13,59 +13,71 @@ namespace Botan {
 /*
 * Blowfish Encryption
 */
-void Blowfish::enc(const byte in[], byte out[]) const
+void Blowfish::encrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
    const u32bit* S1 = S + 0;
    const u32bit* S2 = S + 256;
    const u32bit* S3 = S + 512;
    const u32bit* S4 = S + 768;
 
-   u32bit L = load_be<u32bit>(in, 0);
-   u32bit R = load_be<u32bit>(in, 1);
-
-   for(u32bit j = 0; j != 16; j += 2)
+   for(u32bit i = 0; i != blocks; ++i)
       {
-      L ^= P[j];
-      R ^= ((S1[get_byte(0, L)]  + S2[get_byte(1, L)]) ^
-             S3[get_byte(2, L)]) + S4[get_byte(3, L)];
+      u32bit L = load_be<u32bit>(in, 0);
+      u32bit R = load_be<u32bit>(in, 1);
 
-      R ^= P[j+1];
-      L ^= ((S1[get_byte(0, R)]  + S2[get_byte(1, R)]) ^
-             S3[get_byte(2, R)]) + S4[get_byte(3, R)];
-      }
+      for(u32bit j = 0; j != 16; j += 2)
+         {
+         L ^= P[j];
+         R ^= ((S1[get_byte(0, L)]  + S2[get_byte(1, L)]) ^
+                S3[get_byte(2, L)]) + S4[get_byte(3, L)];
 
-   L ^= P[16]; R ^= P[17];
+         R ^= P[j+1];
+         L ^= ((S1[get_byte(0, R)]  + S2[get_byte(1, R)]) ^
+                S3[get_byte(2, R)]) + S4[get_byte(3, R)];
+         }
+
+      L ^= P[16]; R ^= P[17];
 
-   store_be(out, R, L);
+      store_be(out, R, L);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
 * Blowfish Decryption
 */
-void Blowfish::dec(const byte in[], byte out[]) const
+void Blowfish::decrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
    const u32bit* S1 = S + 0;
    const u32bit* S2 = S + 256;
    const u32bit* S3 = S + 512;
    const u32bit* S4 = S + 768;
 
-   u32bit L = load_be<u32bit>(in, 0);
-   u32bit R = load_be<u32bit>(in, 1);
-
-   for(u32bit j = 17; j != 1; j -= 2)
+   for(u32bit i = 0; i != blocks; ++i)
       {
-      L ^= P[j];
-      R ^= ((S1[get_byte(0, L)]  + S2[get_byte(1, L)]) ^
-             S3[get_byte(2, L)]) + S4[get_byte(3, L)];
+      u32bit L = load_be<u32bit>(in, 0);
+      u32bit R = load_be<u32bit>(in, 1);
 
-      R ^= P[j-1];
-      L ^= ((S1[get_byte(0, R)]  + S2[get_byte(1, R)]) ^
-             S3[get_byte(2, R)]) + S4[get_byte(3, R)];
-      }
+      for(u32bit j = 17; j != 1; j -= 2)
+         {
+         L ^= P[j];
+         R ^= ((S1[get_byte(0, L)]  + S2[get_byte(1, L)]) ^
+                S3[get_byte(2, L)]) + S4[get_byte(3, L)];
 
-   L ^= P[1]; R ^= P[0];
+         R ^= P[j-1];
+         L ^= ((S1[get_byte(0, R)]  + S2[get_byte(1, R)]) ^
+                S3[get_byte(2, R)]) + S4[get_byte(3, R)];
+         }
+
+      L ^= P[1]; R ^= P[0];
 
-   store_be(out, R, L);
+      store_be(out, R, L);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
diff --git a/src/block/blowfish/blowfish.h b/src/block/blowfish/blowfish.h
index f0f26418d..3623c2087 100644
--- a/src/block/blowfish/blowfish.h
+++ b/src/block/blowfish/blowfish.h
@@ -1,6 +1,6 @@
 /*
 * Blowfish
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2009 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
@@ -23,8 +23,8 @@ class BOTAN_DLL Blowfish : public BlockCipher
       BlockCipher* clone() const { return new Blowfish; }
       Blowfish() : BlockCipher(8, 1, 56) {}
    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);
       void generate_sbox(u32bit[], u32bit, u32bit&, u32bit&) const;