Add ROTR macro in m2d_perm, add comments, typos.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@763 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/algos/md2.c b/algos/md2.c
index 208fd08ea53a88b7076215a590c03403ae73eb7e..edd9fa8c2a54df0ce4652544302f1276a9e7ac0e 100755 (executable)
--- a/algos/md2.c
+++ b/algos/md2.c
@@ -7,14 +7,24 @@
  *
  * \brief MD2 Message-Digest algorithm.
  *
+ * The MD2 algorithm work with a constant array of 256 permutationt
+ * defined in RFC1319. If you don't want to use a standard array of 
+ * permutatione you can use a md2_perm() function that generate an 
+ * array of 256 "casual" permutation. To swich from a standard array 
+ * to md2_perm function you must chanche CONFIG_MD2_STD_PERM defined in 
+ * appconfig.h.
+ * If you need to store array in program memory you must define 
+ * a macro _PROGMEM (for more info see mware/pgm.h).
+ *
+ *
  * \version $Id$
  * \author Daniele Basile <asterix@develer.com>
  */
 
 /*#*
  *#* $Log$
- *#* Revision 1.14  2007/02/06 09:47:53  asterix
- *#* Typo.
+ *#* Revision 1.15  2007/02/06 15:53:34  asterix
+ *#* Add ROTR macro in m2d_perm, add comments, typos.
  *#*
  *#* Revision 1.13  2007/02/05 18:44:42  asterix
  *#* Add md2_perm function.
@@ -50,16 +60,16 @@
 #include <string.h>           //memset(), memcpy();
 #include <cfg/compiler.h>
 #include <cfg/debug.h>        //ASSERT()
-#include <cfg/macros.h>       //MIN(), countof();
+#include <cfg/macros.h>       //MIN(), countof(), ROTR();
 #include <mware/pgm.h>   
 
 
-#ifdef STD_PERMUTATION
+#if CONFIG_MD2_STD_PERM
        /*
        * Official array of 256 byte pemutation contructed from digits of pi, defined
        * in the RFC 1319.
        */
-       static const uint8_t PROGMEM md2_perm[256] = 
+       static const uint8_t PGM_ATTR md2_perm[256] = 
        {
        41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
        19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
@@ -80,6 +90,8 @@
        166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
        31, 26, 219, 153, 141, 51, 159, 17, 131, 20
        };
+
+       #define MD2_PERM(x) PGM_READ_CHAR(&md2_perm[x])
 #else
        /**
         * Md2_perm() function generate an array of 256 "casual" permutation.
@@ -95,34 +107,22 @@
        #define X  172
        /*\}*/
 
-uint8_t md2_perm(uint8_t i)
-{
+       static uint8_t md2_perm(uint8_t i)
+       {
 
-       i = i * K1;
-       i = (i >> R) ^ (i << R); //Rotate i for R times.
-       i ^=  X;
-       i = i * K2;
-
-       return i;
-}
-       
-#endif
+               i = i * K1;
+               i = ROTR(i, R);
+               i ^=  X;
+               i = i * K2;
 
+               return i;
+       }
 
-#if CPU_HARVARD 
-       #ifdef STD_PERMUTATION
-               #define MD2_PERM(x) pgm_read_char(&md2_permr[x]) //Read from program memory, if CPU is harvard
-       #else
-               #define MD2_PERM(x) pgm_read_char(&md2_permr(x)) //Read from program memory, if CPU is harvard
-       #endif
-#else
-       #ifdef STD_PERMUTATION
-               #define MD2_PERM(x) md2_perm[x]                  //
-       #else
-               #define MD2_PERM(x) md2_perm(x)                  //
-       #endif
+       #define MD2_PERM(x) md2_perm(x)
+               
 #endif
 
+
 /**
  * Pad function. Put len_pad unsigned char in
  * input block.