X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=trivium%2Ftrivium.c;h=737a0680be7190db331ca40aacb68bd5930d5341;hb=deca11a7e7be5605c387aa2cd577e22925854ff8;hp=3ac69c3b263eb60848d8252feaf97cc0d944840d;hpb=d32eba56ce10ea6b9eff123b50d9842673b38f2b;p=avr-crypto-lib.git

diff --git a/trivium/trivium.c b/trivium/trivium.c
index 3ac69c3..737a068 100644
--- a/trivium/trivium.c
+++ b/trivium/trivium.c
@@ -28,18 +28,20 @@
 #include <stdint.h>
 #include <string.h>
 #include "trivium.h"
+#include <avr/pgmspace.h>
 
-#define S(i) ((((*ctx)[(i)/8])>>((i)%8))&1)
-uint8_t trivium_enc(trivium_ctx_t* ctx){
+#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 = S(65)  ^ S(92);
-	t2 = S(161) ^ S(176);
-	t3 = S(242) ^ S(287);
+	t1 = G(65)  ^ G(92);
+	t2 = G(161) ^ G(176);
+	t3 = G(242) ^ G(287);
 	z  = t1^t2^t3;
-	t1 ^= (S(90)  & S(91))  ^ S(170);
-	t2 ^= (S(174) & S(175)) ^ S(263);
-	t3 ^= (S(285) & S(286)) ^ S(68);
+	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;
@@ -49,32 +51,62 @@ uint8_t trivium_enc(trivium_ctx_t* ctx){
 		c1=c2;
 	}
 	/* insert ts */
-	(*ctx)[0] = (((*ctx)[0])&0xFE)| t3; /* s0*/
-	(*ctx)[93/8] = (((*ctx)[93/8])& (~(1<<(93%8)))) | (t1<<(93%8)); /* s93 */
-	(*ctx)[177/8] = (((*ctx)[177/8])& (~(1<<(177%8)))) | (t2<<(177%8));/* s177 */
+	S(0, t3);
+	S(93, t1);
+	S(177, t2);
 	
-	return z;
+	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)
 
-void trivium_init(const void* key, uint8_t keysize_b, 
-                  const void* iv,  uint8_t ivsize_b,
-                  trivium_ctx_t* ctx){
-	uint16_t i;
-	uint8_t c1=0,c2;
+static const uint8_t rev_table[16] PROGMEM = {
+	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);
-	memcpy((*ctx), key, KEYSIZE_B);
-	memcpy((*ctx)+12, iv, IVSIZE_B); /* iv0 is at s96, must shift to s93 */
-	
+	c2=0;
+	c1=KEYSIZE_B;
+	do{
+		t1 = ((uint8_t*)key)[--c1];
+		t2 = (pgm_read_byte(&(rev_table[t1&0x0f]))<<4)|(pgm_read_byte(&(rev_table[t1>>4])));
+		(*ctx)[c2++] = t2;
+	}while(c1!=0);
+
+	c2=12;
+	c1=IVSIZE_B;
+	do{
+		t1 = ((uint8_t*)iv)[--c1];
+		t2 = (pgm_read_byte(&(rev_table[t1&0x0f]))<<4)|(pgm_read_byte(&(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;
+
+	(*ctx)[35] = 0xE0;
 	
 	for(i=0; i<4*288; ++i){
 		trivium_enc(ctx);