1 /*
2  *  VIA PadLock support functions
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6  */
7 /*
8  *  This implementation is based on the VIA PadLock Programming Guide:
9  *
10  *  http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/
11  *  programming_guide.pdf
12  */
13 
14 #include "common.h"
15 
16 #if defined(MBEDTLS_PADLOCK_C)
17 
18 #include "padlock.h"
19 
20 #include <string.h>
21 
22 #if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
23 
24 /*
25  * PadLock detection routine
26  */
mbedtls_padlock_has_support(int feature)27 int mbedtls_padlock_has_support(int feature)
28 {
29     static int flags = -1;
30     int ebx = 0, edx = 0;
31 
32     if (flags == -1) {
33         asm ("movl  %%ebx, %0           \n\t"
34              "movl  $0xC0000000, %%eax  \n\t"
35              "cpuid                     \n\t"
36              "cmpl  $0xC0000001, %%eax  \n\t"
37              "movl  $0, %%edx           \n\t"
38              "jb    1f                  \n\t"
39              "movl  $0xC0000001, %%eax  \n\t"
40              "cpuid                     \n\t"
41              "1:                        \n\t"
42              "movl  %%edx, %1           \n\t"
43              "movl  %2, %%ebx           \n\t"
44              : "=m" (ebx), "=m" (edx)
45              :  "m" (ebx)
46              : "eax", "ecx", "edx");
47 
48         flags = edx;
49     }
50 
51     return flags & feature;
52 }
53 
54 /*
55  * PadLock AES-ECB block en(de)cryption
56  */
mbedtls_padlock_xcryptecb(mbedtls_aes_context * ctx,int mode,const unsigned char input[16],unsigned char output[16])57 int mbedtls_padlock_xcryptecb(mbedtls_aes_context *ctx,
58                               int mode,
59                               const unsigned char input[16],
60                               unsigned char output[16])
61 {
62     int ebx = 0;
63     uint32_t *rk;
64     uint32_t *blk;
65     uint32_t *ctrl;
66     unsigned char buf[256];
67 
68     rk = ctx->buf + ctx->rk_offset;
69 
70     if (((long) rk & 15) != 0) {
71         return MBEDTLS_ERR_PADLOCK_DATA_MISALIGNED;
72     }
73 
74     blk = MBEDTLS_PADLOCK_ALIGN16(buf);
75     memcpy(blk, input, 16);
76 
77     ctrl = blk + 4;
78     *ctrl = 0x80 | ctx->nr | ((ctx->nr + (mode^1) - 10) << 9);
79 
80     asm ("pushfl                        \n\t"
81          "popfl                         \n\t"
82          "movl    %%ebx, %0             \n\t"
83          "movl    $1, %%ecx             \n\t"
84          "movl    %2, %%edx             \n\t"
85          "movl    %3, %%ebx             \n\t"
86          "movl    %4, %%esi             \n\t"
87          "movl    %4, %%edi             \n\t"
88          ".byte  0xf3,0x0f,0xa7,0xc8    \n\t"
89          "movl    %1, %%ebx             \n\t"
90          : "=m" (ebx)
91          :  "m" (ebx), "m" (ctrl), "m" (rk), "m" (blk)
92          : "memory", "ecx", "edx", "esi", "edi");
93 
94     memcpy(output, blk, 16);
95 
96     return 0;
97 }
98 
99 /*
100  * PadLock AES-CBC buffer en(de)cryption
101  */
mbedtls_padlock_xcryptcbc(mbedtls_aes_context * ctx,int mode,size_t length,unsigned char iv[16],const unsigned char * input,unsigned char * output)102 int mbedtls_padlock_xcryptcbc(mbedtls_aes_context *ctx,
103                               int mode,
104                               size_t length,
105                               unsigned char iv[16],
106                               const unsigned char *input,
107                               unsigned char *output)
108 {
109     int ebx = 0;
110     size_t count;
111     uint32_t *rk;
112     uint32_t *iw;
113     uint32_t *ctrl;
114     unsigned char buf[256];
115 
116     rk = ctx->buf + ctx->rk_offset;
117 
118     if (((long) input  & 15) != 0 ||
119         ((long) output & 15) != 0 ||
120         ((long) rk & 15) != 0) {
121         return MBEDTLS_ERR_PADLOCK_DATA_MISALIGNED;
122     }
123 
124     iw = MBEDTLS_PADLOCK_ALIGN16(buf);
125     memcpy(iw, iv, 16);
126 
127     ctrl = iw + 4;
128     *ctrl = 0x80 | ctx->nr | ((ctx->nr + (mode ^ 1) - 10) << 9);
129 
130     count = (length + 15) >> 4;
131 
132     asm ("pushfl                        \n\t"
133          "popfl                         \n\t"
134          "movl    %%ebx, %0             \n\t"
135          "movl    %2, %%ecx             \n\t"
136          "movl    %3, %%edx             \n\t"
137          "movl    %4, %%ebx             \n\t"
138          "movl    %5, %%esi             \n\t"
139          "movl    %6, %%edi             \n\t"
140          "movl    %7, %%eax             \n\t"
141          ".byte  0xf3,0x0f,0xa7,0xd0    \n\t"
142          "movl    %1, %%ebx             \n\t"
143          : "=m" (ebx)
144          :  "m" (ebx), "m" (count), "m" (ctrl),
145          "m"  (rk), "m" (input), "m" (output), "m" (iw)
146          : "memory", "eax", "ecx", "edx", "esi", "edi");
147 
148     memcpy(iv, iw, 16);
149 
150     return 0;
151 }
152 
153 #endif /* MBEDTLS_VIA_PADLOCK_HAVE_CODE */
154 
155 #endif /* MBEDTLS_PADLOCK_C */
156