+DES/3DES

[avr-crypto-lib.git] / shabea.c

diff --git a/shabea.c b/shabea.c
new file mode 100644 (file)
index 0000000..f4f823c
--- /dev/null
+++ b/shabea.c
@@ -0,0 +1,64 @@
+/**
+ * \file       shabea.c
+ * \author     Daniel Otte 
+ * \date       2007-06-07
+ * \brief      SHABEA - a SHA Based Encrytion Algorithm implementation
+ * \par License        
+ * GPL
+ * 
+ * SHABEAn-r where n is the blocksize and r the number of round used
+ * 
+ * 
+ */
+#include <stdlib.h>
+#include <string.h>
+#include "sha256.h"
+
+#include "config.h"
+#include "uart.h"
+#include "debug.h"
+/*
+ * 
+ */
+static
+void memxor(uint8_t * dest, uint8_t * src, uint8_t length){
+       while(length--){
+               *dest++ ^= *src++;
+       }
+} 
+
+/*
+ * SHABEA128-16
+ */ 
+#define L ((uint8_t*)block+0)
+#define R ((uint8_t*)block+8)
+void shabea128(void * block, void * key, uint16_t keysize, uint8_t enc, uint8_t rounds){
+       int8_t r;               /**/
+       uint8_t *tb;    /**/
+       uint16_t kbs;   /* bytes used for the key / temporary block */
+       sha256_hash_t hash;
+       
+       r = (enc?0:(rounds-1));
+       kbs = keysize/8 + ((keysize&7)?1:0);
+       tb = malloc(8+2+kbs);
+       memcpy(tb+8+2, key, kbs);
+       tb[8+0] = 0;
+       
+       for(;r!=(enc?(rounds):-1);enc?r++:r--){ /* enc: 0..(rounds-1) ; !enc: (rounds-1)..0 */
+               memcpy(tb, R, 8); /* copy right half into tb */
+               tb[8+1] = r;
+               sha256(hash, tb, 64+16+keysize);
+               if(!(r==(enc?(rounds-1):0))){   
+                       /* swap */
+                       memxor(hash, L, 8);
+                       memcpy(L, R, 8);
+                       memcpy(R, hash, 8);
+               } else {
+                       /* no swap */
+                       memxor(L, hash, 8);     
+               }
+       }
+       free(tb);
+}
+
+