src/xyssl/padlock.c

   1 /*
   2  *  VIA PadLock support functions
   3  *
   4  *  Copyright (C) 2006-2007  Christophe Devine
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20 /*
  21  *  This implementation is based on the VIA PadLock Programming Guide:
  22  *
  23  *  http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/
  24  *  programming_guide.pdf
  25  */
  26
  27 #include "xyssl/config.h"
  28
  29 #if defined(XYSSL_PADLOCK_C)
  30
  31 #include "xyssl/aes.h"
  32 #include "xyssl/padlock.h"
  33
  34 #if defined(XYSSL_HAVE_X86)
  35
  36 #include <string.h>
  37
  38 /*
  39  * PadLock detection routine
  40  */
  41 int padlock_supports( int feature )
  42 {
  43     static int flags = -1;
  44     int ebx, edx;
  45
  46     if( flags == -1 )
  47     {
  48         asm( "movl  %%ebx, %0           \n"     \
  49              "movl  $0xC0000000, %%eax  \n"     \
  50              "cpuid                     \n"     \
  51              "cmpl  $0xC0000001, %%eax  \n"     \
  52              "movl  $0, %%edx           \n"     \
  53              "jb    unsupported         \n"     \
  54              "movl  $0xC0000001, %%eax  \n"     \
  55              "cpuid                     \n"     \
  56              "unsupported:              \n"     \
  57              "movl  %%edx, %1           \n"     \
  58              "movl  %2, %%ebx           \n"
  59              : "=m" (ebx), "=m" (edx)
  60              :  "m" (ebx)
  61              : "eax", "ecx", "edx" );
  62
  63         flags = edx;
  64     }
  65
  66     return( flags & feature );
  67 }
  68
  69 /*
  70  * PadLock AES-ECB block en(de)cryption
  71  */
  72 int padlock_xcryptecb( aes_context *ctx,
  73                        int mode,
  74                        unsigned char input[16],
  75                        unsigned char output[16] )
  76 {
  77     int ebx;
  78     unsigned long *rk;
  79     unsigned long *blk;
  80     unsigned long *ctrl;
  81     unsigned char buf[256];
  82
  83     rk  = ctx->rk;
  84     blk = PADLOCK_ALIGN16( buf );
  85     memcpy( blk, input, 16 );
  86
  87      ctrl = blk + 4;
  88     *ctrl = 0x80 | ctx->nr | ( ( ctx->nr + ( mode^1 ) - 10 ) << 9 );
  89
  90     asm( "pushfl; popfl         \n"     \
  91          "movl    %%ebx, %0     \n"     \
  92          "movl    $1, %%ecx     \n"     \
  93          "movl    %2, %%edx     \n"     \
  94          "movl    %3, %%ebx     \n"     \
  95          "movl    %4, %%esi     \n"     \
  96          "movl    %4, %%edi     \n"     \
  97          ".byte  0xf3,0x0f,0xa7,0xc8\n" \
  98          "movl    %1, %%ebx     \n"
  99          : "=m" (ebx)
 100          :  "m" (ebx), "m" (ctrl), "m" (rk), "m" (blk)
 101          : "ecx", "edx", "esi", "edi" );
 102
 103     memcpy( output, blk, 16 );
 104
 105     return( 0 );
 106 }
 107
 108 /*
 109  * PadLock AES-CBC buffer en(de)cryption
 110  */
 111 int padlock_xcryptcbc( aes_context *ctx,
 112                        int mode,
 113                        int length,
 114                        unsigned char iv[16],
 115                        unsigned char *input,
 116                        unsigned char *output )
 117 {
 118     int ebx, count;
 119     unsigned long *rk;
 120     unsigned long *iw;
 121     unsigned long *ctrl;
 122     unsigned char buf[256];
 123
 124     if( ( (long) input  & 15 ) != 0 ||
 125         ( (long) output & 15 ) != 0 )
 126         return( 1 );
 127
 128     rk = ctx->rk;
 129     iw = PADLOCK_ALIGN16( buf );
 130     memcpy( iw, iv, 16 );
 131
 132      ctrl = iw + 4;
 133     *ctrl = 0x80 | ctx->nr | ( ( ctx->nr + (mode^1) - 10 ) << 9 );
 134
 135     count = (length + 15) >> 4;
 136
 137     asm( "pushfl; popfl         \n"     \
 138          "movl    %%ebx, %0     \n"     \
 139          "movl    %2, %%ecx     \n"     \
 140          "movl    %3, %%edx     \n"     \
 141          "movl    %4, %%ebx     \n"     \
 142          "movl    %5, %%esi     \n"     \
 143          "movl    %6, %%edi     \n"     \
 144          "movl    %7, %%eax     \n"     \
 145          ".byte  0xf3,0x0f,0xa7,0xd0\n" \
 146          "movl    %1, %%ebx     \n"
 147          : "=m" (ebx)
 148          :  "m" (ebx), "m" (count), "m" (ctrl),
 149             "m"  (rk), "m" (input), "m" (output), "m" (iw)
 150          : "eax", "ecx", "edx", "esi", "edi" );
 151
 152     memcpy( iv, iw, 16 );
 153
 154     return( 0 );
 155 }
 156
 157 #endif
 158
 159 #endif