improving present

[arm-crypto-lib.git] / present / present128.c

diff --git a/present/present128.c b/present/present128.c
new file mode 100644 (file)
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+++ b/present/present128.c
@@ -0,0 +1,145 @@
+/* present128.c */
+/*
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 2008  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/>.
+*/
+/**
+ * present128.c
+ * a implementation of the PRESENT block-cipher
+ * author: Daniel Otte
+ * email:  daniel.otte@rub.de
+ * license: GPLv3
+ * 
+ * */
+ 
+#include <string.h>
+#include <stdint.h> 
+#include "memxor.h"
+#include "present_common.h"
+#include "present128.h"
+
+static
+void key_update_128(uint8_t* buffer, uint8_t round){
+       uint8_t j;
+       uint8_t t8;
+       union __attribute__((packed)){
+               uint8_t   v8[2];
+               uint16_t v16;
+       } tmp;
+       /* rotate buffer 67 right */
+       for(j=0; j<8; ++j){
+               tmp.v8[0] = buffer[j];
+               buffer[j] = buffer[j + 8];
+               buffer[j + 8] = tmp.v8[0];
+       }
+       j=0;
+       t8 = (uint16_t)buffer[15] << (5);
+       do{
+               tmp.v8[1] = buffer[j];
+               tmp.v16 >>= 3;
+               buffer[j] = tmp.v8[1] | t8;
+               t8 = tmp.v8[0] & 0xe0;
+       }while(++j<16);
+       /* rotating done now substitution */
+       buffer[0] = present_sbox(buffer[0]);
+       /* xor with round counter */
+       buffer[8] ^= round << 6;
+       buffer[7] ^= round >> 2;
+}
+
+
+static
+void key_update_128_inv(uint8_t* buffer, uint8_t round){
+       uint8_t j;
+       uint8_t t8;
+       union __attribute__((packed)){
+               uint8_t   v8[2];
+               uint16_t v16;
+       } tmp;
+       /* xor with round counter */
+       buffer[8] ^= round << 6;
+       buffer[7] ^= round >> 2;
+
+       /* rotating done now substitution */
+       buffer[0] = present_sbox_inv(buffer[0]);
+
+       /* rotate buffer 67 left */
+       for(j=0; j<8; ++j){
+               tmp.v8[0] = buffer[j];
+               buffer[j] = buffer[j + 8];
+               buffer[j + 8] = tmp.v8[0];
+       }
+       j=15;
+       t8 = (uint16_t)buffer[0] >> (5);
+       do{
+               tmp.v8[0] = buffer[j];
+               tmp.v16 <<= 3;
+               buffer[j] = tmp.v8[0] | t8;
+               t8 = tmp.v8[1] & 0x07;
+       }while(j--);
+}
+
+void present128_init(const uint8_t* key, uint8_t keysize_b, present128_ctx_t* ctx){
+       uint8_t i;
+       memcpy(ctx->fwd_key, key, 16);
+       memcpy(ctx->rev_key, key, 16);
+       for(i=1; i<32; ++i){
+               key_update_128(ctx->rev_key, i);
+       }
+}
+
+void present128_enc(void* buffer, present128_ctx_t* ctx){
+       present_generic_enc(buffer, (uint8_t*)ctx, 16, key_update_128);
+}
+
+void present128_dec(void* buffer, present128_ctx_t* ctx){
+       present_generic_dec(buffer, (uint8_t*)ctx, 16, key_update_128_inv);
+}
+
+/*
+void present128_enc(void* buffer, present128_ctx_t* ctx){
+       uint8_t i,j,tmp[8], k[16];
+       memcpy(k, ctx->fwd_key, 16);
+       memxor(buffer, k, 8);
+       for(i=1; i<32; ++i){
+               j = 7;
+               do{
+                       tmp[j] = present_sbox(((uint8_t*)buffer)[j]);
+               }while(j--);
+               present_p(buffer, tmp);
+               key_update_128(k, i);
+               memxor(buffer, k, 8);
+       }
+}
+
+void present128_dec(void* buffer, present128_ctx_t* ctx){
+       uint8_t j,tmp[8], k[16];
+       uint8_t i;
+       memcpy(k, ctx->rev_key, 16);
+       memxor(buffer, k, 8);
+       i = 31;
+       do{
+               present_p(tmp, buffer);
+               present_p(buffer, tmp);
+               j = 7;
+               do{
+                       ((uint8_t*)buffer)[j] = present_sbox_inv(((uint8_t*)buffer)[j]);
+               }while(j--);
+               key_update_128_inv(k, i);
+               memxor(buffer, k, 8);
+       }while(--i);
+}
+*/