advances in serpent asm implementation

[avr-crypto-lib.git] / serpent.c

diff --git a/serpent.c b/serpent.c
index 7042a41083ad69424040f2994ac97792ca7ab401..c90b099e36848421b2b1b53d00ccf884c401ad39 100644 (file)
--- a/serpent.c
+++ b/serpent.c
@@ -26,21 +26,12 @@
 #include <stdint.h>
 #include <string.h> /* memset() */
 #include <avr/pgmspace.h>
+#include "memxor.h"
 #include "serpent.h"
 #include "serpent-sboxes.h"
 
 /******************************************************************************/
 
-void memxor(void * dest, void * src, uint8_t size){
-       while(size--){
-               *((uint8_t*)dest) ^= *((uint8_t*)src);
-               dest = (uint8_t*)dest +1;
-               src  = (uint8_t*)src  +1;
-       }
-}
-
-/******************************************************************************/
-
 uint32_t rotl32(uint32_t a, uint8_t n){
        return ((a<<n) | (a>>(32-n)));
 }
@@ -92,10 +83,10 @@ static uint32_t gen_w(uint32_t * b, uint8_t i){
 } 
 
 /* key must be 256bit (32 byte) large! */
-void serpent_genctx(void * key, uint8_t keysize, serpent_ctx_t * ctx){
+void serpent_init(const void* key, uint16_t keysize, serpent_ctx_t* ctx){
        uint32_t buffer[8];
        uint8_t i,j;
-       if(keysize){
+       if(keysize<256){
                /* keysize is less than 256 bit, padding needed */
                memset(buffer, 0, 32);
                memcpy(buffer, key, (keysize+7)/8);
@@ -117,31 +108,31 @@ void serpent_genctx(void * key, uint8_t keysize, serpent_ctx_t * ctx){
 }
 
 
-void serpent_enc(void* buffer, serpent_ctx_t * ctx){
+void serpent_enc(void* buffer, const serpent_ctx_t* ctx){
        uint8_t i;
        for(i=0; i<31; ++i){
-               memxor((uint8_t*)buffer, ctx->k[i], 16);
+               memxor(buffer, ctx->k[i], 16);
                sbox128(buffer, i);
                lt((uint8_t*)buffer);
        }
-       memxor((uint8_t*)buffer, ctx->k[i], 16);
+       memxor(buffer, ctx->k[i], 16);
        sbox128(buffer, i);
        ++i;
-       memxor((uint8_t*)buffer, ctx->k[i], 16);
+       memxor(buffer, ctx->k[i], 16);
 }
 
-void serpent_dec(void* buffer, serpent_ctx_t * ctx){
+void serpent_dec(void* buffer, const serpent_ctx_t* ctx){
        int8_t i=32;
        
-       memxor((uint8_t*)buffer, ctx->k[i], 16);
+       memxor(buffer, ctx->k[i], 16);
        --i;
        inv_sbox128(buffer, i);
        memxor((uint8_t*)buffer, ctx->k[i], 16);
        --i;
        for(; i>=0; --i){
-               inv_lt((uint8_t*)buffer);
+               inv_lt(buffer);
                inv_sbox128(buffer, i);
-               memxor((uint8_t*)buffer, ctx->k[i], 16);
+               memxor(buffer, ctx->k[i], 16);
        }
 }