Add md2_perm function.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@757 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/algos/md2.c b/algos/md2.c
index 4eee4ecd5e60ea82ce1905ab9bebafe0e22f39ff..1e6fd0e57ebeed6888b5b89a2d83a970a56e0aa6 100755 (executable)
--- a/algos/md2.c
+++ b/algos/md2.c
@@ -13,6 +13,9 @@
 
 /*#*
  *#* $Log$
+ *#* Revision 1.13  2007/02/05 18:44:42  asterix
+ *#* Add md2_perm function.
+ *#*
  *#* Revision 1.12  2007/02/05 16:52:44  asterix
  *#* Add define for harvard architecture.
  *#*
@@ -48,36 +51,72 @@
 #include <mware/pgm.h>   
 
 
-/*
- * Official array of 256 byte pemutation contructed from digits of pi, defined
- * in the RFC 1319.
- */
-static const uint8_t PROGMEM md2_perm[256] = 
+#ifdef STD_PERMUTATION
+       /*
+       * Official array of 256 byte pemutation contructed from digits of pi, defined
+       * in the RFC 1319.
+       */
+       static const uint8_t PROGMEM 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,
+       76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
+       138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
+       245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
+       148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
+       39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
+       181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
+       150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
+       112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
+       96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
+       85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
+       234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
+       129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
+       8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
+       203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
+       166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
+       31, 26, 219, 153, 141, 51, 159, 17, 131, 20
+       };
+#else
+       /**
+        * Md2_perm() function generate an array of 256 "casual" permutation.
+        */
+       
+       /**
+        * Costant define for computing an array of 256 "casual" permutation.
+        */
+       #define K1 5
+       #define K2 3
+       #define R  2
+       #define X  172
+
+
+uint8_t md2_perm(uint8_t i)
 {
-  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,
-  76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
-  138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
-  245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
-  148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
-  39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
-  181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
-  150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
-  112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
-  96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
-  85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
-  234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
-  129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
-  8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
-  203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
-  166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
-  31, 26, 219, 153, 141, 51, 159, 17, 131, 20
-};
-
-#if CPU_HARVARD
-       #define MD2_PERM(x) pgm_read_char(&md2_perm[x]) //Read from program memory, if CPU is harvard
+
+       i = i * K1;
+       i = (i >> R) ^ (i << R); //Rotate i for R times.
+       i ^=  X;
+       i = i * K2;
+
+       return i;
+}
+       
+#endif
+
+
+#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
-       #define MD2_PERM(x) md2_perm[x]                 //Normaly from a const array.
+       #ifdef STD_PERMUTATION
+               #define MD2_PERM(x) md2_perm[x]                  //
+       #else
+               #define MD2_PERM(x) md2_perm(x)                  //
+       #endif
 #endif
 
 /**