padlock.c

00001 /*
00002  *  VIA PadLock support functions
00003  *
00004  *  Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
00005  *
00006  *  This file is part of mbed TLS (https://tls.mbed.org)
00007  *
00008  *  This program is free software; you can redistribute it and/or modify
00009  *  it under the terms of the GNU General Public License as published by
00010  *  the Free Software Foundation; either version 2 of the License, or
00011  *  (at your option) any later version.
00012  *
00013  *  This program is distributed in the hope that it will be useful,
00014  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  *  GNU General Public License for more details.
00017  *
00018  *  You should have received a copy of the GNU General Public License along
00019  *  with this program; if not, write to the Free Software Foundation, Inc.,
00020  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00021  */
00022 /*
00023  *  This implementation is based on the VIA PadLock Programming Guide:
00024  *
00025  *  http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/
00026  *  programming_guide.pdf
00027  */
00028 
00029 #if !defined(POLARSSL_CONFIG_FILE)
00030 #include "polarssl/config.h"
00031 #else
00032 #include POLARSSL_CONFIG_FILE
00033 #endif
00034 
00035 #if defined(POLARSSL_PADLOCK_C)
00036 
00037 #include "polarssl/padlock.h"
00038 
00039 #include <string.h>
00040 
00041 #if defined(POLARSSL_HAVE_X86)
00042 
00043 /*
00044  * PadLock detection routine
00045  */
00046 int padlock_supports( int feature )
00047 {
00048     static int flags = -1;
00049     int ebx = 0, edx = 0;
00050 
00051     if( flags == -1 )
00052     {
00053         asm( "movl  %%ebx, %0           \n\t"
00054              "movl  $0xC0000000, %%eax  \n\t"
00055              "cpuid                     \n\t"
00056              "cmpl  $0xC0000001, %%eax  \n\t"
00057              "movl  $0, %%edx           \n\t"
00058              "jb    unsupported         \n\t"
00059              "movl  $0xC0000001, %%eax  \n\t"
00060              "cpuid                     \n\t"
00061              "unsupported:              \n\t"
00062              "movl  %%edx, %1           \n\t"
00063              "movl  %2, %%ebx           \n\t"
00064              : "=m" (ebx), "=m" (edx)
00065              :  "m" (ebx)
00066              : "eax", "ecx", "edx" );
00067 
00068         flags = edx;
00069     }
00070 
00071     return( flags & feature );
00072 }
00073 
00074 /*
00075  * PadLock AES-ECB block en(de)cryption
00076  */
00077 int padlock_xcryptecb( aes_context *ctx,
00078                        int mode,
00079                        const unsigned char input[16],
00080                        unsigned char output[16] )
00081 {
00082     int ebx = 0;
00083     uint32_t *rk;
00084     uint32_t *blk;
00085     uint32_t *ctrl;
00086     unsigned char buf[256];
00087 
00088     rk  = ctx->rk ;
00089     blk = PADLOCK_ALIGN16( buf );
00090     memcpy( blk, input, 16 );
00091 
00092      ctrl = blk + 4;
00093     *ctrl = 0x80 | ctx->nr  | ( ( ctx->nr  + ( mode^1 ) - 10 ) << 9 );
00094 
00095     asm( "pushfl                        \n\t"
00096          "popfl                         \n\t"
00097          "movl    %%ebx, %0             \n\t"
00098          "movl    $1, %%ecx             \n\t"
00099          "movl    %2, %%edx             \n\t"
00100          "movl    %3, %%ebx             \n\t"
00101          "movl    %4, %%esi             \n\t"
00102          "movl    %4, %%edi             \n\t"
00103          ".byte  0xf3,0x0f,0xa7,0xc8    \n\t"
00104          "movl    %1, %%ebx             \n\t"
00105          : "=m" (ebx)
00106          :  "m" (ebx), "m" (ctrl), "m" (rk), "m" (blk)
00107          : "memory", "ecx", "edx", "esi", "edi" );
00108 
00109     memcpy( output, blk, 16 );
00110 
00111     return( 0 );
00112 }
00113 
00114 /*
00115  * PadLock AES-CBC buffer en(de)cryption
00116  */
00117 int padlock_xcryptcbc( aes_context *ctx,
00118                        int mode,
00119                        size_t length,
00120                        unsigned char iv[16],
00121                        const unsigned char *input,
00122                        unsigned char *output )
00123 {
00124     int ebx = 0;
00125     size_t count;
00126     uint32_t *rk;
00127     uint32_t *iw;
00128     uint32_t *ctrl;
00129     unsigned char buf[256];
00130 
00131     if( ( (long) input  & 15 ) != 0 ||
00132         ( (long) output & 15 ) != 0 )
00133         return( POLARSSL_ERR_PADLOCK_DATA_MISALIGNED );
00134 
00135     rk = ctx->rk ;
00136     iw = PADLOCK_ALIGN16( buf );
00137     memcpy( iw, iv, 16 );
00138 
00139      ctrl = iw + 4;
00140     *ctrl = 0x80 | ctx->nr  | ( ( ctx->nr  + ( mode ^ 1 ) - 10 ) << 9 );
00141 
00142     count = ( length + 15 ) >> 4;
00143 
00144     asm( "pushfl                        \n\t"
00145          "popfl                         \n\t"
00146          "movl    %%ebx, %0             \n\t"
00147          "movl    %2, %%ecx             \n\t"
00148          "movl    %3, %%edx             \n\t"
00149          "movl    %4, %%ebx             \n\t"
00150          "movl    %5, %%esi             \n\t"
00151          "movl    %6, %%edi             \n\t"
00152          "movl    %7, %%eax             \n\t"
00153          ".byte  0xf3,0x0f,0xa7,0xd0    \n\t"
00154          "movl    %1, %%ebx             \n\t"
00155          : "=m" (ebx)
00156          :  "m" (ebx), "m" (count), "m" (ctrl),
00157             "m"  (rk), "m" (input), "m" (output), "m" (iw)
00158          : "memory", "eax", "ecx", "edx", "esi", "edi" );
00159 
00160     memcpy( iv, iw, 16 );
00161 
00162     return( 0 );
00163 }
00164 
00165 #endif /* POLARSSL_HAVE_X86 */
00166 
00167 #endif /* POLARSSL_PADLOCK_C */
00168