xref: /third_party/mbedtls/library/padlock.c (revision a8e1175b)
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 */
27int 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 */
57int 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#if defined(MBEDTLS_CIPHER_MODE_CBC)
100/*
101 * PadLock AES-CBC buffer en(de)cryption
102 */
103int mbedtls_padlock_xcryptcbc(mbedtls_aes_context *ctx,
104                              int mode,
105                              size_t length,
106                              unsigned char iv[16],
107                              const unsigned char *input,
108                              unsigned char *output)
109{
110    int ebx = 0;
111    size_t count;
112    uint32_t *rk;
113    uint32_t *iw;
114    uint32_t *ctrl;
115    unsigned char buf[256];
116
117    rk = ctx->buf + ctx->rk_offset;
118
119    if (((long) input  & 15) != 0 ||
120        ((long) output & 15) != 0 ||
121        ((long) rk & 15) != 0) {
122        return MBEDTLS_ERR_PADLOCK_DATA_MISALIGNED;
123    }
124
125    iw = MBEDTLS_PADLOCK_ALIGN16(buf);
126    memcpy(iw, iv, 16);
127
128    ctrl = iw + 4;
129    *ctrl = 0x80 | ctx->nr | ((ctx->nr + (mode ^ 1) - 10) << 9);
130
131    count = (length + 15) >> 4;
132
133    asm ("pushfl                        \n\t"
134         "popfl                         \n\t"
135         "movl    %%ebx, %0             \n\t"
136         "movl    %2, %%ecx             \n\t"
137         "movl    %3, %%edx             \n\t"
138         "movl    %4, %%ebx             \n\t"
139         "movl    %5, %%esi             \n\t"
140         "movl    %6, %%edi             \n\t"
141         "movl    %7, %%eax             \n\t"
142         ".byte  0xf3,0x0f,0xa7,0xd0    \n\t"
143         "movl    %1, %%ebx             \n\t"
144         : "=m" (ebx)
145         :  "m" (ebx), "m" (count), "m" (ctrl),
146         "m"  (rk), "m" (input), "m" (output), "m" (iw)
147         : "memory", "eax", "ecx", "edx", "esi", "edi");
148
149    memcpy(iv, iw, 16);
150
151    return 0;
152}
153#endif /* MBEDTLS_CIPHER_MODE_CBC */
154
155#endif /* MBEDTLS_VIA_PADLOCK_HAVE_CODE */
156
157#endif /* MBEDTLS_PADLOCK_C */
158