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 u8[] to u32 in a portable way
  30  *      s_vPutUINT32 - Convert from u32 to u8[] 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 /*
  46  * static u32 s_dwGetUINT32(u8 * p);         Get u32 from
  47  *                                                      4 bytes LSByte first
  48  * static void s_vPutUINT32(u8* p, u32 val); Put u32 into
  49  *                                                      4 bytes LSByte first
  50  */
  51 static void s_vClear(void);             /* Clear the internal message,
  52                                          * resets the object to the
  53                                          * state just after construction. */
  54 static void s_vSetKey(u32 dwK0, u32 dwK1);
  55 static void s_vAppendByte(u8 b);        /* Add a single byte to the internal
  56                                          * message */
  57
  58 static u32  L, R;               /* Current state */
  59 static u32  K0, K1;             /* Key */
  60 static u32  M;          /* Message accumulator (single word) */
  61 static unsigned int   nBytesInM;        /* # bytes in M */
  62
  63 /*
  64 static u32 s_dwGetUINT32 (u8 * p)
  65 // Convert from u8[] to u32 in a portable way
  66 {
  67         u32 res = 0;
  68         unsigned int i;
  69         for (i = 0; i < 4; i++)
  70                 res |= (*p++) << (8*i);
  71         return res;
  72 }
  73
  74 static void s_vPutUINT32(u8 *p, u32 val)
  75 // Convert from u32 to u8[] in a portable way
  76 {
  77         unsigned int i;
  78         for (i = 0; i < 4; i++) {
  79                 *p++ = (u8) (val & 0xff);
  80                 val >>= 8;
  81         }
  82 }
  83 */
  84
  85 static void s_vClear(void)
  86 {
  87         /* Reset the state to the empty message. */
  88         L = K0;
  89         R = K1;
  90         nBytesInM = 0;
  91         M = 0;
  92 }
  93
  94 static void s_vSetKey(u32 dwK0, u32 dwK1)
  95 {
  96         /* Set the key */
  97         K0 = dwK0;
  98         K1 = dwK1;
  99         /* and reset the message */
 100         s_vClear();
 101 }
 102
 103 static void s_vAppendByte(u8 b)
 104 {
 105         /* Append the byte to our word-sized buffer */
 106         M |= b << (8*nBytesInM);
 107         nBytesInM++;
 108         /* Process the word if it is full. */
 109         if (nBytesInM >= 4) {
 110                 L ^= M;
 111                 R ^= ROL32(L, 17);
 112                 L += R;
 113                 R ^= ((L & 0xff00ff00) >> 8) | ((L & 0x00ff00ff) << 8);
 114                 L += R;
 115                 R ^= ROL32(L, 3);
 116                 L += R;
 117                 R ^= ROR32(L, 2);
 118                 L += R;
 119                 /* Clear the buffer */
 120                 M = 0;
 121                 nBytesInM = 0;
 122         }
 123 }
 124
 125 void MIC_vInit(u32 dwK0, u32 dwK1)
 126 {
 127         /* Set the key */
 128         s_vSetKey(dwK0, dwK1);
 129 }
 130
 131 void MIC_vUnInit(void)
 132 {
 133         /* Wipe the key material */
 134         K0 = 0;
 135         K1 = 0;
 136
 137         /* And the other fields as well. */
 138         /* Note that this sets (L,R) to (K0,K1) which is just fine. */
 139         s_vClear();
 140 }
 141
 142 void MIC_vAppend(u8 * src, unsigned int nBytes)
 143 {
 144     /* This is simple */
 145         while (nBytes > 0) {
 146                 s_vAppendByte(*src++);
 147                 nBytes--;
 148         }
 149 }
 150
 151 void MIC_vGetMIC(u32 * pdwL, u32 * pdwR)
 152 {
 153         /* Append the minimum padding */
 154         s_vAppendByte(0x5a);
 155         s_vAppendByte(0);
 156         s_vAppendByte(0);
 157         s_vAppendByte(0);
 158         s_vAppendByte(0);
 159         /* and then zeroes until the length is a multiple of 4 */
 160         while (nBytesInM != 0)
 161                 s_vAppendByte(0);
 162         /* The s_vAppendByte function has already computed the result. */
 163         *pdwL = L;
 164         *pdwR = R;
 165         /* Reset to the empty message. */
 166         s_vClear();
 167 }