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, 16 insertions, 6 deletions

diff --git a/src/block/serpent_ia32/serp_ia32.cpp b/src/block/serpent_ia32/serp_ia32.cpp
index 37dd4e637..997bec2fc 100644
--- a/src/block/serpent_ia32/serp_ia32.cpp
+++ b/src/block/serpent_ia32/serp_ia32.cpp
@@ -21,17 +21,27 @@ void botan_serpent_ia32_key_schedule(u32bit[140]);
 /*
 * Serpent Encryption
 */
-void Serpent_IA32::enc(const byte in[], byte out[]) const
+void Serpent_IA32::encrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   botan_serpent_ia32_encrypt(in, out, round_key);
+   for(u32bit i = 0; i != blocks; ++i)
+      {
+      botan_serpent_ia32_encrypt(in, out, round_key);
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
 * Serpent Decryption
 */
-void Serpent_IA32::dec(const byte in[], byte out[]) const
+void Serpent_IA32::decrypt_n(const byte in[], byte out[], u32bit blocks) const
    {
-   botan_serpent_ia32_decrypt(in, out, round_key);
+   for(u32bit i = 0; i != blocks; ++i)
+      {
+      botan_serpent_ia32_decrypt(in, out, round_key);
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
    }
 
 /*
diff --git a/src/block/serpent_ia32/serp_ia32.h b/src/block/serpent_ia32/serp_ia32.h
index 565e9889d..2b4a95d3d 100644
--- a/src/block/serpent_ia32/serp_ia32.h
+++ b/src/block/serpent_ia32/serp_ia32.h
@@ -20,8 +20,8 @@ class BOTAN_DLL Serpent_IA32 : public Serpent
    public:
       BlockCipher* clone() const { return new Serpent_IA32; }
    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);
    };