adding trivium

[arm-crypto-lib.git] / trivium / trivium.c

diff --git a/trivium/trivium.c b/trivium/trivium.c
new file mode 100644 (file)
index 0000000..92040bd
--- /dev/null
+++ b/trivium/trivium.c
@@ -0,0 +1,115 @@
+/* trivium.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/>.
+*/
+/**
+ * 
+ * author: Daniel Otte
+ * email:  daniel.otte@rub.de
+ * license: GPLv3
+ * 
+ */
+
+ 
+#include <stdint.h>
+#include <string.h>
+#include "trivium.h"
+
+#define G(i) ((((*ctx)[(i)/8])>>(((i)%8)))&1)
+#define S(i,v) ((*ctx)[(i)/8] = (((*ctx)[(i)/8]) & (uint8_t)~(1<<((i)%8))) | ((v)<<((i)%8)))
+uint8_t trivium_enc(trivium_ctx_t* ctx){
+       uint8_t t1,t2,t3,z;
+       
+       t1 = G(65)  ^ G(92);
+       t2 = G(161) ^ G(176);
+       t3 = G(242) ^ G(287);
+       z  = t1^t2^t3;
+       t1 ^= (G(90)  & G(91))  ^ G(170);
+       t2 ^= (G(174) & G(175)) ^ G(263);
+       t3 ^= (G(285) & G(286)) ^ G(68);
+       
+       /* shift whole state and insert ts later */
+       uint8_t i,c1=0,c2;
+       for(i=0; i<36; ++i){
+               c2=(((*ctx)[i])>>7);
+               (*ctx)[i] = (((*ctx)[i])<<1)|c1;
+               c1=c2;
+       }
+       /* insert ts */
+       S(0, t3);
+       S(93, t1);
+       S(177, t2);
+       
+       return z?0x080:0x00;
+}
+
+uint8_t trivium_getbyte(trivium_ctx_t *ctx){
+       uint8_t r=0, i=0;
+       do{
+               r>>=1;
+               r |= trivium_enc(ctx);
+       }while(++i<8);
+       return r;
+}
+
+#define KEYSIZE_B ((keysize_b+7)/8)
+#define IVSIZE_B  ((ivsize_b +7)/8)
+
+static const uint8_t rev_table[16] = {
+       0x00, 0x08, 0x04, 0x0C,   /* 0000 1000 0100 1100 */
+       0x02, 0x0A, 0x06, 0x0E,   /* 0010 1010 0110 1110 */
+       0x01, 0x09, 0x05, 0x0D,   /* 0001 1001 0101 1101 */
+       0x03, 0x0B, 0x07, 0x0F    /* 0011 1011 0111 1111 */
+};
+
+void trivium_init(const void* key, uint16_t keysize_b,
+                  const void* iv,  uint16_t ivsize_b,
+                  trivium_ctx_t* ctx){
+       uint16_t i;
+       uint8_t c1,c2;
+       uint8_t t1,t2;
+       memset((*ctx)+KEYSIZE_B, 0, 35-KEYSIZE_B);
+       c2=0;
+       c1=KEYSIZE_B;
+       do{
+               t1 = ((uint8_t*)key)[--c1];
+               t2 = (rev_table[t1&0x0f]<<4)|(rev_table[t1>>4]);
+               (*ctx)[c2++] = t2;
+       }while(c1!=0);
+
+       c2=12;
+       c1=IVSIZE_B;
+       do{
+               t1 = ((uint8_t*)iv)[--c1];
+               t2 = (rev_table[t1&0x0f]<<4)|(rev_table[t1>>4]);
+               (*ctx)[c2++] = t2;
+       }while(c1!=0);
+
+       for(i=12+IVSIZE_B; i>10; --i){
+               c2=(((*ctx)[i])<<5);
+               (*ctx)[i] = (((*ctx)[i])>>3)|c1;
+               c1=c2;
+       }
+
+       (*ctx)[35] = 0xE0;
+       
+       for(i=0; i<4*288; ++i){
+               trivium_enc(ctx);
+       }
+}
+
+