Write md2_compute function.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@747 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/algos/md2.c b/algos/md2.c
index 13be3f220adcfe78a100fca555c2c0b307c579ad..9f4099dae3a65b3755666c31f7cbea2276e21e3b 100755 (executable)
--- a/algos/md2.c
+++ b/algos/md2.c
@@ -13,8 +13,8 @@
 
 /*#*
  *#* $Log$
- *#* Revision 1.3  2007/01/31 10:31:04  asterix
- *#* Write md2_pad funtion.
+ *#* Revision 1.4  2007/01/31 13:51:57  asterix
+ *#* Write md2_compute function.
  *#*
  *#* Revision 1.2  2007/01/30 17:31:44  asterix
  *#* Add function prototypes.
@@ -57,7 +57,7 @@ static uint8_t md2_perm[256] =
 /**
  * Pad function. Fill input array with unsigned char until 
  * lenght of block is equal to CONFIG_MD2_BLOCK_LEN.
- * 
+ *
  */
 static void md2_pad(void *block, size_t len_pad)
 {
@@ -72,7 +72,50 @@ static void md2_pad(void *block, size_t len_pad)
 
 static void md2_compute(void *state, void *checksum, void *block)
 {
+       int t=0;        
+       uint8_t compute_array[CONFIG_MD2_BLOCK_LEN * 3];
+       
+       /*
+        * Copy state and checksum context in compute array. 
+        */
+       memcpy(compute_array, state, CONFIG_MD2_BLOCK_LEN);
+       memcpy(compute_array + CONFIG_MD2_BLOCK_LEN, state, CONFIG_MD2_BLOCK_LEN);
+       
+       /*
+        * Fill compute array with state XOR block
+        */
+       for(int i=0; i< CONFIG_MD2_BLOCK_LEN; i++)
+               compute_array[i + (CONFIG_MD2_BLOCK_LEN * 2)] = state[i] ^ block[i];
+       
+       /*
+        * Encryt block.
+        */
+       for(i=0; i<NUM_COMPUTE_ROUNDS; i++)
+       {
+               for(int j=0; j<COMPUTE_ARRAY_LEN; j++)
+               {
+                       compute_array[j] ^= md2_perm [t];
+                       t = compute_array[j];
+               }
+               
+               t = (t + i) & 0xff; //modulo 256.
+       }
+       /*
+        * Update checksum.     
+        */
+       t = checksum[CONFIG_MD2_BLOCK_LEN - 1];
 
+       for(i=0; i< CONFIG_MD2_BLOCK_LEN; i++)
+       {
+               checksum[i]  ^= md2_perm [block[i] ^ t];
+               t = checksum[i];
+       }
+       
+       /*
+        * Update state and clean compute array. 
+        */
+       memcpy(state, compute_array, CONFIG_MD2_BLOCK_LEN);
+       memset(compute_array, 0, sizeof(compute_array));
 }
 
 /**