X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=grain%2Fgrain.c;h=ff6b97de41b46b689c211635d0d9613d557bca36;hb=701cee0d98aab48dd3192c8cc7c77eb42581bc56;hp=8d30d2266299a367a2f5891daa0220f58642fe2d;hpb=d32eba56ce10ea6b9eff123b50d9842673b38f2b;p=avr-crypto-lib.git

diff --git a/grain/grain.c b/grain/grain.c
index 8d30d22..ff6b97d 100644
--- a/grain/grain.c
+++ b/grain/grain.c
@@ -40,10 +40,10 @@
 #define _B(i) (((ctx->nfsr[9-((i)/8)])>>(7-((i)%8)))&1)
 
 
-uint8_t h_lut[4] PROGMEM = {0x4C, 0xB6, 0xD3, 0x26};
+const uint8_t h_lut[4] PROGMEM = {0x4C, 0xB6, 0xD3, 0x26};
 
 #ifdef GRAIN_BADOPTIMISATION
-uint8_t g_lut[128] PROGMEM = {
+const uint8_t g_lut[128] PROGMEM = {
         0xF0, 0xA5, 0x0F, 0x5A, 0x0F, 0x5A, 0xF0, 0xA5, 0x0F, 0x5A, 0xF0, 0xA5, 0xF0, 0x5A, 0x0F, 0x0F, 
         0xC3, 0x96, 0x3C, 0x69, 0x3C, 0x69, 0xC3, 0x96, 0x9C, 0xC9, 0x63, 0x36, 0x63, 0xC9, 0x9C, 0x9C, 
         0x0F, 0x5A, 0x0F, 0x5A, 0xF0, 0xA5, 0xF0, 0x5A, 0xF0, 0xA5, 0xF0, 0xA5, 0x0F, 0xA5, 0x0F, 0xF0, 
@@ -134,7 +134,17 @@ uint8_t grain_enc(grain_ctx_t* ctx){
 	h = (pgm_read_byte(h_lut+(i/8)))>>(i%8);
 	
 	h ^= B(0) ^ B(1) ^ B(3) ^ B(9) ^ B(30) ^ B(42) ^ B(55);
-	return h&1;
+	return (h&1);
+}
+
+uint8_t grain_getbyte(grain_ctx_t* ctx){
+	uint8_t i=0;
+	uint8_t r=0;
+	do{
+		r >>= 1;
+		r |= grain_enc(ctx)?0x80:0x00;
+	}while(++i<8);
+	return r;
 }
 
 #ifdef GRAIN_REVERSEKEY