1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/* hwfeatures.c - Detect hardware features.
* Copyright (C) 2007, 2011 Free Software Foundation, Inc.
* Copyright (C) 2012 g10 Code GmbH
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#ifdef HAVE_SYSLOG
# include <syslog.h>
#endif /*HAVE_SYSLOG*/
#include "g10lib.h"
#include "hwf-common.h"
/* The name of a file used to globally disable selected features. */
#define HWF_DENY_FILE "/etc/gcrypt/hwf.deny"
/* A table to map hardware features to a string. */
static struct
{
unsigned int flag;
const char *desc;
} hwflist[] =
{
{ HWF_PADLOCK_RNG, "padlock-rng" },
{ HWF_PADLOCK_AES, "padlock-aes" },
{ HWF_PADLOCK_SHA, "padlock-sha" },
{ HWF_PADLOCK_MMUL,"padlock-mmul"},
{ HWF_INTEL_CPU, "intel-cpu" },
{ HWF_INTEL_BMI2, "intel-bmi2" },
{ HWF_INTEL_SSSE3, "intel-ssse3" },
{ HWF_INTEL_PCLMUL,"intel-pclmul" },
{ HWF_INTEL_AESNI, "intel-aesni" },
{ HWF_INTEL_RDRAND,"intel-rdrand" },
{ HWF_INTEL_AVX, "intel-avx" },
{ HWF_INTEL_AVX2, "intel-avx2" },
{ HWF_ARM_NEON, "arm-neon" }
};
/* A bit vector with the hardware features which shall not be used.
This variable must be set prior to any initialization. */
static unsigned int disabled_hw_features;
/* A bit vector describing the hardware features currently
available. */
static unsigned int hw_features;
/* Convenience macros. */
#define my_isascii(c) (!((c) & 0x80))
/* Disable a feature by name. This function must be called *before*
_gcry_detect_hw_features is called. */
gpg_err_code_t
_gcry_disable_hw_feature (const char *name)
{
int i;
for (i=0; i < DIM (hwflist); i++)
if (!strcmp (hwflist[i].desc, name))
{
disabled_hw_features |= hwflist[i].flag;
return 0;
}
return GPG_ERR_INV_NAME;
}
/* Return a bit vector describing the available hardware features.
The HWF_ constants are used to test for them. */
unsigned int
_gcry_get_hw_features (void)
{
return hw_features;
}
/* Enumerate all features. The caller is expected to start with an
IDX of 0 and then increment IDX until NULL is returned. */
const char *
_gcry_enum_hw_features (int idx, unsigned int *r_feature)
{
if (idx < 0 || idx >= DIM (hwflist))
return NULL;
if (r_feature)
*r_feature = hwflist[idx].flag;
return hwflist[idx].desc;
}
/* Read a file with features which shall not be used. The file is a
simple text file where empty lines and lines with the first non
white-space character being '#' are ignored. */
static void
parse_hwf_deny_file (void)
{
const char *fname = HWF_DENY_FILE;
FILE *fp;
char buffer[256];
char *p, *pend;
int i, lnr = 0;
fp = fopen (fname, "r");
if (!fp)
return;
for (;;)
{
if (!fgets (buffer, sizeof buffer, fp))
{
if (!feof (fp))
{
#ifdef HAVE_SYSLOG
syslog (LOG_USER|LOG_WARNING,
"Libgcrypt warning: error reading '%s', line %d",
fname, lnr);
#endif /*HAVE_SYSLOG*/
}
fclose (fp);
return;
}
lnr++;
for (p=buffer; my_isascii (*p) && isspace (*p); p++)
;
pend = strchr (p, '\n');
if (pend)
*pend = 0;
pend = p + (*p? (strlen (p)-1):0);
for ( ;pend > p; pend--)
if (my_isascii (*pend) && isspace (*pend))
*pend = 0;
if (!*p || *p == '#')
continue;
for (i=0; i < DIM (hwflist); i++)
{
if (!strcmp (hwflist[i].desc, p))
{
disabled_hw_features |= hwflist[i].flag;
break;
}
}
if (i == DIM (hwflist))
{
#ifdef HAVE_SYSLOG
syslog (LOG_USER|LOG_WARNING,
"Libgcrypt warning: unknown feature in '%s', line %d",
fname, lnr);
#endif /*HAVE_SYSLOG*/
}
}
}
/* Detect the available hardware features. This function is called
once right at startup and we assume that no other threads are
running. */
void
_gcry_detect_hw_features (void)
{
hw_features = 0;
if (fips_mode ())
return; /* Hardware support is not to be evaluated. */
parse_hwf_deny_file ();
#if defined (HAVE_CPU_ARCH_X86)
{
hw_features = _gcry_hwf_detect_x86 ();
}
#endif /* HAVE_CPU_ARCH_X86 */
#if defined (HAVE_CPU_ARCH_ARM)
{
hw_features = _gcry_hwf_detect_arm ();
}
#endif /* HAVE_CPU_ARCH_ARM */
hw_features &= ~disabled_hw_features;
}
|
