release/src-rt/bcmcrypto/tkmic.c

   1 /*
   2  *   tkmic.c - TKIP Message Integrity Check (MIC) functions
   3  *
   4  * Copyright (C) 2010, Broadcom Corporation
   5  * All Rights Reserved.
   6  *
   7  * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Broadcom Corporation;
   8  * the contents of this file may not be disclosed to third parties, copied
   9  * or duplicated in any form, in whole or in part, without the prior
  10  * written permission of Broadcom Corporation.
  11  *
  12  * $Id: tkmic.c,v 1.2.540.1 2010-04-22 22:27:54 Exp $
  13  */
  14
  15 #include <typedefs.h>
  16 #include <bcmendian.h>
  17 #include <bcmcrypto/tkmic.h>
  18
  19 /*
  20  * "Michael" Messge Integrity Check (MIC) algorithm
  21  */
  22 static INLINE void
  23 tkip_micblock(uint32 *left, uint32 *right)
  24 {
  25         uint32 l = *left;
  26         uint32 r = *right;
  27
  28         r ^= ROTR32(l, 15);
  29         l += r; /* mod 2^32 */
  30         r ^= XSWAP32(l);
  31         l += r; /* mod 2^32 */
  32         r ^= ROTR32(l, 29);
  33         l += r; /* mod 2^32 */
  34         r ^= ROTR32(l, 2);
  35         l += r; /* mod 2^32 */
  36
  37         *left = l;
  38         *right = r;
  39 }
  40
  41
  42 /* compute mic across message */
  43 /* buffer must already have terminator and padding appended */
  44 /* buffer length (n) specified in bytes */
  45 void
  46 BCMROMFN(tkip_mic)(uint32 k0, uint32 k1, int n, uint8 *m, uint32 *left, uint32 *right)
  47 {
  48         uint32 l = k0;
  49         uint32 r = k1;
  50
  51         if (((uintptr)m & 3) == 0) {
  52                 for (; n > 0; n -= 4) {
  53                         l ^= ltoh32(*(uint *)m);
  54                         m += 4;
  55                         tkip_micblock(&l, &r);
  56                 }
  57         } else {
  58                 for (; n > 0; n -= 4) {
  59                         l ^= ltoh32_ua(m);
  60                         m += 4;
  61                         tkip_micblock(&l, &r);
  62                 }
  63         }
  64         *left = l;
  65         *right = r;
  66 }
  67
  68 /* append the MIC terminator to the data buffer */
  69 /* terminator is 0x5a followed by 4-7 bytes of 0 */
  70 /* param 'o' is the current frag's offset in the frame */
  71 /* returns length of message plus terminator in bytes */
  72 int
  73 BCMROMFN(tkip_mic_eom)(uint8 *m, uint n, uint o)
  74 {
  75         uint8 *mend = m + n;
  76         uint t = n + o;
  77         mend[0] = 0x5a;
  78         mend[1] = 0;
  79         mend[2] = 0;
  80         mend[3] = 0;
  81         mend[4] = 0;
  82         mend += 5;
  83         o += n + 5;
  84         while (o++%4) {
  85                 *mend++ = 0;
  86         }
  87         return (n+o-1-t);
  88 }