X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=grain_h_lutgen.c;fp=grain_h_lutgen.c;h=4b5ede074a157d3d52eb0a3cb21895314829fe7e;hb=2b3e134485c42a28f4d8d981c8cb62dc27e71aa5;hp=0000000000000000000000000000000000000000;hpb=a953544ad2ba88da1442608f24add2e602800f17;p=avr-crypto-lib.git

diff --git a/grain_h_lutgen.c b/grain_h_lutgen.c
new file mode 100644
index 0000000..4b5ede0
--- /dev/null
+++ b/grain_h_lutgen.c
@@ -0,0 +1,60 @@
+/**
+ * 
+ * author: Daniel Otte
+ * email:  daniel.otte@rub.de
+ * license: GPLv3
+ *
+ * this program generate a lookuptable for the h-function in grain 
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+#define X(i) ((x)>>((i)))
+uint8_t h(uint8_t x){
+	uint8_t h;
+	
+	h = (X(1)) ^ (X(4)) ^ 
+	    (X(0)&X(3)) ^ (X(2)&X(3)) ^ (X(3)&X(4)) ^ 
+	    (X(0)&X(1)&X(2)) ^ (X(0)&X(2)&X(3)) ^ (X(0)&X(2)&X(4)) ^ 
+	    (X(1)&X(2)&X(4)) ^ (X(2)&X(3)&X(4)) ;
+	
+	return h&1;
+}
+
+int main(void){
+	uint8_t i; 
+	uint32_t lut;
+	puts(
+	"/* \n"
+	" * author: Daniel Otte \n"
+	" * email:  daniel.otte@rub.de  \n"
+	" * license: GPLv3 \n"
+	" *  \n"
+	" * this program generate a lookuptable for the h-function in grain  \n"
+	" *  \n"
+	" */ \n");
+	puts("/* \n"
+	     " * x0 x1 x2 x3 x4 - h");
+	
+	for(i=0; i<0x20; ++i){
+		printf(" *  %c  %c  %c  %c  %c - %c\n",
+			(i&0x01)?'1':'0',
+			(i&0x02)?'1':'0',
+			(i&0x04)?'1':'0',
+			(i&0x08)?'1':'0',
+			(i&0x10)?'1':'0',
+			(h(i))?'1':'0' );
+			lut >>=1;
+			lut |= h(i)?0x80000000:0x00000000;
+			if(i%4==3){	
+				puts(" * --");
+			}
+	}
+	puts(" */\n");
+	printf(" uint8_t lut[4]= {0x%2.2X, 0x%2.2X, 0x%2.2X, 0x%2.2X} \n",
+		lut&0xFF, (lut>>8)&0xFF, (lut>>16)&0xFF, (lut>>24)&0xFF);
+		
+	return 0; 
+}
+