common/mbedtls/padlock.c

   1 /*
   2  *  VIA PadLock support functions
   3  *
   4  *  Copyright The Mbed TLS Contributors
   5  *  SPDX-License-Identifier: Apache-2.0
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
   8  *  not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *  http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19 /*
  20  *  This implementation is based on the VIA PadLock Programming Guide:
  21  *
  22  *  http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/
  23  *  programming_guide.pdf
  24  */
  25
  26 #include "common.h"
  27
  28 #if defined(MBEDTLS_PADLOCK_C)
  29
  30 #include "mbedtls/padlock.h"
  31
  32 #include <string.h>
  33
  34 #ifndef asm
  35 #define asm __asm
  36 #endif
  37
  38 #if defined(MBEDTLS_HAVE_X86)
  39
  40 /*
  41  * PadLock detection routine
  42  */
  43 int mbedtls_padlock_has_support(int feature) {
  44     static int flags = -1;
  45     int ebx = 0, edx = 0;
  46
  47     if (flags == -1) {
  48         asm("movl  %%ebx, %0           \n\t"
  49             "movl  $0xC0000000, %%eax  \n\t"
  50             "cpuid                     \n\t"
  51             "cmpl  $0xC0000001, %%eax  \n\t"
  52             "movl  $0, %%edx           \n\t"
  53             "jb    1f                  \n\t"
  54             "movl  $0xC0000001, %%eax  \n\t"
  55             "cpuid                     \n\t"
  56             "1:                        \n\t"
  57             "movl  %%edx, %1           \n\t"
  58             "movl  %2, %%ebx           \n\t"
  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 mbedtls_padlock_xcryptecb(mbedtls_aes_context *ctx,
  73                               int mode,
  74                               const unsigned char input[16],
  75                               unsigned char output[16]) {
  76     int ebx = 0;
  77     uint32_t *rk;
  78     uint32_t *blk;
  79     uint32_t *ctrl;
  80     unsigned char buf[256];
  81
  82     rk  = ctx->rk;
  83     blk = MBEDTLS_PADLOCK_ALIGN16(buf);
  84     memcpy(blk, input, 16);
  85
  86     ctrl = blk + 4;
  87     *ctrl = 0x80 | ctx->nr | ((ctx->nr + (mode ^ 1) - 10) << 9);
  88
  89     asm("pushfl                        \n\t"
  90         "popfl                         \n\t"
  91         "movl    %%ebx, %0             \n\t"
  92         "movl    $1, %%ecx             \n\t"
  93         "movl    %2, %%edx             \n\t"
  94         "movl    %3, %%ebx             \n\t"
  95         "movl    %4, %%esi             \n\t"
  96         "movl    %4, %%edi             \n\t"
  97         ".byte  0xf3,0x0f,0xa7,0xc8    \n\t"
  98         "movl    %1, %%ebx             \n\t"
  99         : "=m"(ebx)
 100         :  "m"(ebx), "m"(ctrl), "m"(rk), "m"(blk)
 101         : "memory", "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 mbedtls_padlock_xcryptcbc(mbedtls_aes_context *ctx,
 112                               int mode,
 113                               size_t length,
 114                               unsigned char iv[16],
 115                               const unsigned char *input,
 116                               unsigned char *output) {
 117     int ebx = 0;
 118     size_t count;
 119     uint32_t *rk;
 120     uint32_t *iw;
 121     uint32_t *ctrl;
 122     unsigned char buf[256];
 123
 124     if (((long) input  & 15) != 0 ||
 125             ((long) output & 15) != 0)
 126         return (MBEDTLS_ERR_PADLOCK_DATA_MISALIGNED);
 127
 128     rk = ctx->rk;
 129     iw = MBEDTLS_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                        \n\t"
 138         "popfl                         \n\t"
 139         "movl    %%ebx, %0             \n\t"
 140         "movl    %2, %%ecx             \n\t"
 141         "movl    %3, %%edx             \n\t"
 142         "movl    %4, %%ebx             \n\t"
 143         "movl    %5, %%esi             \n\t"
 144         "movl    %6, %%edi             \n\t"
 145         "movl    %7, %%eax             \n\t"
 146         ".byte  0xf3,0x0f,0xa7,0xd0    \n\t"
 147         "movl    %1, %%ebx             \n\t"
 148         : "=m"(ebx)
 149         :  "m"(ebx), "m"(count), "m"(ctrl),
 150         "m"(rk), "m"(input), "m"(output), "m"(iw)
 151         : "memory", "eax", "ecx", "edx", "esi", "edi");
 152
 153     memcpy(iv, iw, 16);
 154
 155     return (0);
 156 }
 157
 158 #endif /* MBEDTLS_HAVE_X86 */
 159
 160 #endif /* MBEDTLS_PADLOCK_C */