/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/*
 51static unsigned long s_dwGetUINT32(unsigned char *p);         // Get unsigned long from 4 bytes LSByte first
 52static void s_vPutUINT32(unsigned char *p, unsigned long val); // Put unsigned long into 4 bytes LSByte first
 53*/
 54static void s_vClear(void);                       // Clear the internal message,
 55                                              // resets the object to the state just after construction.
 56static void s_vSetKey(unsigned long dwK0, unsigned long dwK1);
 57static void s_vAppendByte(unsigned char b);            // Add a single byte to the internal message
 58
 59/*---------------------  Export Variables  --------------------------*/
 60static unsigned long L, R;           // Current state
 61
 62static unsigned long K0, K1;         // Key
 63static unsigned long M;              // Message accumulator (single word)
 64static unsigned int nBytesInM;      // # bytes in M
 65
 66/*---------------------  Export Functions  --------------------------*/
 67
 68/*
 69static 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
 81static 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    {
 87        *p++ = (unsigned char) (val & 0xff);
 88        val >>= 8;
 89    }
 90}
 91*/
 92
 93static 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
102static void s_vSetKey (unsigned long dwK0, unsigned long dwK1)
103{
104    // Set the key
105    K0 = dwK0;
106    K1 = dwK1;
107    // and reset the message
108    s_vClear();
109}
110
111static void s_vAppendByte (unsigned char 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
134void MIC_vInit (unsigned long dwK0, unsigned long dwK1)
135{
136    // Set the key
137    s_vSetKey(dwK0, dwK1);
138}
139
140
141void 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
152void MIC_vAppend (unsigned char *src, unsigned int nBytes)
153{
154    // This is simple
155    while (nBytes > 0)
156    {
157        s_vAppendByte(*src++);
158        nBytes--;
159    }
160}
161
162void MIC_vGetMIC (unsigned long *pdwL, unsigned long *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