new makefile and modified build process

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

diff --git a/skein/threefish256_enc.c b/skein/threefish256_enc.c
new file mode 100644 (file)
index 0000000..8bfbf9d
--- /dev/null
+++ b/skein/threefish256_enc.c
@@ -0,0 +1,86 @@
+/* threefish256_enc.c */
+/*
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 2009  Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * \author  Daniel Otte
+ * \email   daniel.otte@rub.de
+ * \date    2009-03-12
+ * \license GPLv3 or later
+ * 
+ * 
+ * 
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include "threefish.h"
+
+#define X(a) (((uint64_t*)data)[(a)])
+static
+void permute_4(void* data){
+       uint64_t t;
+       t = X(1);
+       X(1) = X(3);
+       X(3) = t;
+}
+
+#define THREEFISH_KEY_CONST 0x5555555555555555LL /* 2**64/3 */
+
+#define K(s) (((uint64_t*)key)[(s)])
+#define T(s) (((uint64_t*)tweak)[(s)])
+
+void threefish256_init(const void* key, const void* tweak, threefish256_ctx_t* ctx){
+       memcpy(ctx->k, key, 4*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);
+       }
+}
+
+static
+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, 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};
+       do{
+               if(i%4==0){
+                       add_key_4(data, ctx, s);
+                       ++s;
+               }
+               threefish_mix(data, r0[i%8]);
+               threefish_mix((uint8_t*)data + 16, r1[i%8]);
+               permute_4(data);
+               ++i;
+       }while(i!=72);
+       add_key_4(data, ctx, s);
+}
+