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 unsigned long s_dwGetUINT32(unsigned char *p);         // Get unsigned long from 4 bytes LSByte first
  52   static void s_vPutUINT32(unsigned char *p, unsigned long val); // Put unsigned long into 4 bytes LSByte first
  53 */
  54 static void s_vClear(void);                       // Clear the internal message,
  55 // resets the object to the state just after construction.
  56 static void s_vSetKey(unsigned long dwK0, unsigned long dwK1);
  57 static void s_vAppendByte(unsigned char b);            // Add a single byte to the internal message
  58
  59 /*---------------------  Export Variables  --------------------------*/
  60 static unsigned long L, R;           // Current state
  61
  62 static unsigned long K0, K1;         // Key
  63 static unsigned long M;              // Message accumulator (single word)
  64 static unsigned int nBytesInM;      // # bytes in M
  65
  66 /*---------------------  Export Functions  --------------------------*/
  67
  68 /*
  69   static unsigned long s_dwGetUINT32 (unsigned char *p)
  70 // Convert from unsigned char [] to unsigned long in a portable way
  71 {
  72 unsigned long res = 0;
  73 unsigned int i;
  74 for (i=0; i<4; i++)
  75 {
  76         res |= (*p++) << (8 * i);
  77 }
  78 return res;
  79 }
  80
  81 static void s_vPutUINT32 (unsigned char *p, unsigned long val)
  82 // Convert from unsigned long to unsigned char [] in a portable way
  83 {
  84         unsigned int i;
  85         for (i=0; i<4; i++) {
  86                 *p++ = (unsigned char) (val & 0xff);
  87                 val >>= 8;
  88         }
  89 }
  90 */
  91
  92 static void s_vClear(void)
  93 {
  94         // Reset the state to the empty message.
  95         L = K0;
  96         R = K1;
  97         nBytesInM = 0;
  98         M = 0;
  99 }
 100
 101 static void s_vSetKey(unsigned long dwK0, unsigned long dwK1)
 102 {
 103         // Set the key
 104         K0 = dwK0;
 105         K1 = dwK1;
 106         // and reset the message
 107         s_vClear();
 108 }
 109
 110 static void s_vAppendByte(unsigned char b)
 111 {
 112         // Append the byte to our word-sized buffer
 113         M |= b << (8*nBytesInM);
 114         nBytesInM++;
 115         // Process the word if it is full.
 116         if (nBytesInM >= 4) {
 117                 L ^= M;
 118                 R ^= ROL32(L, 17);
 119                 L += R;
 120                 R ^= ((L & 0xff00ff00) >> 8) | ((L & 0x00ff00ff) << 8);
 121                 L += R;
 122                 R ^= ROL32(L, 3);
 123                 L += R;
 124                 R ^= ROR32(L, 2);
 125                 L += R;
 126                 // Clear the buffer
 127                 M = 0;
 128                 nBytesInM = 0;
 129         }
 130 }
 131
 132 void MIC_vInit(unsigned long dwK0, unsigned long dwK1)
 133 {
 134         // Set the key
 135         s_vSetKey(dwK0, dwK1);
 136 }
 137
 138 void MIC_vUnInit(void)
 139 {
 140         // Wipe the key material
 141         K0 = 0;
 142         K1 = 0;
 143
 144         // And the other fields as well.
 145         //Note that this sets (L,R) to (K0,K1) which is just fine.
 146         s_vClear();
 147 }
 148
 149 void MIC_vAppend(unsigned char *src, unsigned int nBytes)
 150 {
 151         // This is simple
 152         while (nBytes > 0) {
 153                 s_vAppendByte(*src++);
 154                 nBytes--;
 155         }
 156 }
 157
 158 void MIC_vGetMIC(unsigned long *pdwL, unsigned long *pdwR)
 159 {
 160         // Append the minimum padding
 161         s_vAppendByte(0x5a);
 162         s_vAppendByte(0);
 163         s_vAppendByte(0);
 164         s_vAppendByte(0);
 165         s_vAppendByte(0);
 166         // and then zeroes until the length is a multiple of 4
 167         while (nBytesInM != 0) {
 168                 s_vAppendByte(0);
 169         }
 170         // The s_vAppendByte function has already computed the result.
 171         *pdwL = L;
 172         *pdwR = R;
 173         // Reset to the empty message.
 174         s_vClear();
 175 }