drivers/staging/vt6655/michael.c

   1 /*
   2  * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
   3  * All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  *
  20  * File: michael.cpp
  21  *
  22  * Purpose: The implementation of LIST data structure.
  23  *
  24  * Author: Kyle Hsu
  25  *
  26  * Date: Sep 4, 2002
  27  *
  28  * Functions:
  29  *      s_dwGetUINT32 - Convert from unsigned char [] to unsigned long in a portable way
  30  *      s_vPutUINT32 - Convert from unsigned long to unsigned char [] in a portable way
  31  *      s_vClear - Reset the state to the empty message.
  32  *      s_vSetKey - Set the key.
  33  *      MIC_vInit - Set the key.
  34  *      s_vAppendByte - Append the byte to our word-sized buffer.
  35  *      MIC_vAppend - call s_vAppendByte.
  36  *      MIC_vGetMIC - Append the minimum padding and call s_vAppendByte.
  37  *
  38  * Revision History:
  39  *
  40  */
  41
  42 #include "tmacro.h"
  43 #include "michael.h"
  44
  45 /*---------------------  Static Definitions -------------------------*/
  46
  47 /*---------------------  Static Variables  --------------------------*/
  48
  49 /*---------------------  Static Functions  --------------------------*/
  50
  51 static void s_vClear(void);                       // Clear the internal message,
  52 // resets the object to the state just after construction.
  53 static void s_vSetKey(u32  dwK0, u32  dwK1);
  54 static void s_vAppendByte(unsigned char b);            // Add a single byte to the internal message
  55
  56 /*---------------------  Export Variables  --------------------------*/
  57 static u32 L, R;        /* Current state */
  58
  59 static u32 K0, K1;      /* Key */
  60 static u32 M;           /* Message accumulator (single word) */
  61 static unsigned int nBytesInM;      // # bytes in M
  62
  63 /*---------------------  Export Functions  --------------------------*/
  64
  65 static void s_vClear(void)
  66 {
  67         // Reset the state to the empty message.
  68         L = K0;
  69         R = K1;
  70         nBytesInM = 0;
  71         M = 0;
  72 }
  73
  74 static void s_vSetKey(u32 dwK0, u32 dwK1)
  75 {
  76         // Set the key
  77         K0 = dwK0;
  78         K1 = dwK1;
  79         // and reset the message
  80         s_vClear();
  81 }
  82
  83 static void s_vAppendByte(unsigned char b)
  84 {
  85         // Append the byte to our word-sized buffer
  86         M |= b << (8*nBytesInM);
  87         nBytesInM++;
  88         // Process the word if it is full.
  89         if (nBytesInM >= 4) {
  90                 L ^= M;
  91                 R ^= ROL32(L, 17);
  92                 L += R;
  93                 R ^= ((L & 0xff00ff00) >> 8) | ((L & 0x00ff00ff) << 8);
  94                 L += R;
  95                 R ^= ROL32(L, 3);
  96                 L += R;
  97                 R ^= ROR32(L, 2);
  98                 L += R;
  99                 // Clear the buffer
 100                 M = 0;
 101                 nBytesInM = 0;
 102         }
 103 }
 104
 105 void MIC_vInit(u32 dwK0, u32 dwK1)
 106 {
 107         // Set the key
 108         s_vSetKey(dwK0, dwK1);
 109 }
 110
 111 void MIC_vUnInit(void)
 112 {
 113         // Wipe the key material
 114         K0 = 0;
 115         K1 = 0;
 116
 117         // And the other fields as well.
 118         //Note that this sets (L,R) to (K0,K1) which is just fine.
 119         s_vClear();
 120 }
 121
 122 void MIC_vAppend(unsigned char *src, unsigned int nBytes)
 123 {
 124         // This is simple
 125         while (nBytes > 0) {
 126                 s_vAppendByte(*src++);
 127                 nBytes--;
 128         }
 129 }
 130
 131 void MIC_vGetMIC(u32 *pdwL, u32 *pdwR)
 132 {
 133         // Append the minimum padding
 134         s_vAppendByte(0x5a);
 135         s_vAppendByte(0);
 136         s_vAppendByte(0);
 137         s_vAppendByte(0);
 138         s_vAppendByte(0);
 139         // and then zeroes until the length is a multiple of 4
 140         while (nBytesInM != 0)
 141                 s_vAppendByte(0);
 142
 143         // The s_vAppendByte function has already computed the result.
 144         *pdwL = L;
 145         *pdwR = R;
 146         // Reset to the empty message.
 147         s_vClear();
 148 }