drivers/staging/vt6656/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 BYTE[] to DWORD in a portable way
  30  *      s_vPutUINT32 - Convert from DWORD to BYTE[] 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 DWORD s_dwGetUINT32(BYTE * p);         // Get DWORD from 4 bytes LSByte first
  52 static VOID s_vPutUINT32(BYTE* p, DWORD val); // Put DWORD 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(DWORD dwK0, DWORD dwK1);
  57 static VOID s_vAppendByte(BYTE b);            // Add a single byte to the internal message
  58
  59 /*---------------------  Export Variables  --------------------------*/
  60 static DWORD  L, R;           // Current state
  61
  62 static DWORD  K0, K1;         // Key
  63 static DWORD  M;              // Message accumulator (single word)
  64 static UINT   nBytesInM;      // # bytes in M
  65
  66 /*---------------------  Export Functions  --------------------------*/
  67
  68 /*
  69 static DWORD s_dwGetUINT32 (BYTE * p)
  70 // Convert from BYTE[] to DWORD in a portable way
  71 {
  72     DWORD res = 0;
  73     UINT 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 (BYTE* p, DWORD val)
  82 // Convert from DWORD to BYTE[] in a portable way
  83 {
  84     UINT i;
  85     for(i=0; i<4; i++ )
  86     {
  87         *p++ = (BYTE) (val & 0xff);
  88         val >>= 8;
  89     }
  90 }
  91 */
  92
  93 static VOID s_vClear (void)
  94 {
  95     // Reset the state to the empty message.
  96     L = K0;
  97     R = K1;
  98     nBytesInM = 0;
  99     M = 0;
 100 }
 101
 102 static VOID s_vSetKey (DWORD dwK0, DWORD dwK1)
 103 {
 104     // Set the key
 105     K0 = dwK0;
 106     K1 = dwK1;
 107     // and reset the message
 108     s_vClear();
 109 }
 110
 111 static VOID s_vAppendByte (BYTE b)
 112 {
 113     // Append the byte to our word-sized buffer
 114     M |= b << (8*nBytesInM);
 115     nBytesInM++;
 116     // Process the word if it is full.
 117     if( nBytesInM >= 4 )
 118     {
 119         L ^= M;
 120         R ^= ROL32( L, 17 );
 121         L += R;
 122         R ^= ((L & 0xff00ff00) >> 8) | ((L & 0x00ff00ff) << 8);
 123         L += R;
 124         R ^= ROL32( L, 3 );
 125         L += R;
 126         R ^= ROR32( L, 2 );
 127         L += R;
 128         // Clear the buffer
 129         M = 0;
 130         nBytesInM = 0;
 131     }
 132 }
 133
 134 VOID MIC_vInit (DWORD dwK0, DWORD dwK1)
 135 {
 136     // Set the key
 137     s_vSetKey(dwK0, dwK1);
 138 }
 139
 140
 141 VOID MIC_vUnInit (void)
 142 {
 143     // Wipe the key material
 144     K0 = 0;
 145     K1 = 0;
 146
 147     // And the other fields as well.
 148     //Note that this sets (L,R) to (K0,K1) which is just fine.
 149     s_vClear();
 150 }
 151
 152 VOID MIC_vAppend (PBYTE src, UINT nBytes)
 153 {
 154     // This is simple
 155     while (nBytes > 0)
 156     {
 157         s_vAppendByte(*src++);
 158         nBytes--;
 159     }
 160 }
 161
 162 VOID MIC_vGetMIC (PDWORD pdwL, PDWORD pdwR)
 163 {
 164     // Append the minimum padding
 165     s_vAppendByte(0x5a);
 166     s_vAppendByte(0);
 167     s_vAppendByte(0);
 168     s_vAppendByte(0);
 169     s_vAppendByte(0);
 170     // and then zeroes until the length is a multiple of 4
 171     while( nBytesInM != 0 )
 172     {
 173         s_vAppendByte(0);
 174     }
 175     // The s_vAppendByte function has already computed the result.
 176     *pdwL = L;
 177     *pdwR = R;
 178     // Reset to the empty message.
 179     s_vClear();
 180 }
 181