grøstl, a first impression

[avr-crypto-lib.git] / threefish256_enc.c

diff --git a/threefish256_enc.c b/threefish256_enc.c
index be0d5db412a4b92ba7f7ab2d6d7d4669053ba5aa..8bfbf9de471bad329a6490300d49c25f4e7358b0 100644 (file)
--- a/threefish256_enc.c
+++ b/threefish256_enc.c
@@ -30,16 +30,6 @@
 #include <string.h>
 #include "threefish.h"
 
-#define X0 (((uint64_t*)data)[0])
-#define X1 (((uint64_t*)data)[1])
-static
-void mix(void* data, uint8_t rot){
-       uint64_t x;
-       x = X1;
-       X0 += x;
-       X1 = ((x<<rot)|(x>>(64-rot))) ^ X0;
-}
-
 #define X(a) (((uint64_t*)data)[(a)])
 static
 void permute_4(void* data){
@@ -54,26 +44,30 @@ void permute_4(void* data){
 #define K(s) (((uint64_t*)key)[(s)])
 #define T(s) (((uint64_t*)tweak)[(s)])
 
-void threefish256_init(void* key, void* tweak, threefish256_ctx_t* ctx){
+void threefish256_init(const void* key, const void* tweak, threefish256_ctx_t* ctx){
        memcpy(ctx->k, key, 4*8);
-       memcpy(ctx->t, tweak, 2*8);
+       if(tweak){
+               memcpy(ctx->t, tweak, 2*8);
+               ctx->t[2] = T(0) ^ T(1);
+       }else{
+               memset(ctx->t, 0, 3*8);
+       }
        uint8_t i;
        ctx->k[4] = THREEFISH_KEY_CONST;
        for(i=0; i<4; ++i){
                ctx->k[4] ^= K(i);
        }
-       ctx->t[2] = T(0) ^ T(1);
 }
 
 static
-void add_key_4(void* data, threefish256_ctx_t* ctx, uint8_t s){
+void add_key_4(void* data, const threefish256_ctx_t* ctx, uint8_t s){
        X(0) += ctx->k[(s+0)%5];
        X(1) += ctx->k[(s+1)%5] + ctx->t[s%3];
        X(2) += ctx->k[(s+2)%5] + ctx->t[(s+1)%3];
        X(3) += ctx->k[(s+3)%5] + s;
 }
 
-void threefish256_enc(void* data, threefish256_ctx_t* ctx){
+void threefish256_enc(void* data, const threefish256_ctx_t* ctx){
        uint8_t i=0,s=0;
        uint8_t r0[8] = { 5, 36, 13, 58, 26, 53, 11, 59}; 
        uint8_t r1[8] = {56, 28, 46, 44, 20, 35, 42, 50};
@@ -82,8 +76,8 @@ void threefish256_enc(void* data, threefish256_ctx_t* ctx){
                        add_key_4(data, ctx, s);
                        ++s;
                }
-               mix(data, r0[i%8]);
-               mix((uint8_t*)data + 16, r1[i%8]);
+               threefish_mix(data, r0[i%8]);
+               threefish_mix((uint8_t*)data + 16, r1[i%8]);
                permute_4(data);
                ++i;
        }while(i!=72);