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ef83daf4 | 1 | /* |
556009c5 | 2 | * Copyright 1998-2023 The OpenSSL Project Authors. All Rights Reserved. |
ef83daf4 RL |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use | |
5 | * this file except in compliance with the License. You can obtain a copy | |
6 | * in the file LICENSE in the source distribution or at | |
7 | * https://www.openssl.org/source/license.html | |
8 | */ | |
9 | ||
d5f9166b | 10 | #include "internal/e_os.h" |
ef83daf4 RL |
11 | #include "crypto/cryptlib.h" |
12 | ||
13 | #if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ | |
14 | defined(__x86_64) || defined(__x86_64__) || \ | |
15 | defined(_M_AMD64) || defined(_M_X64) | |
16 | ||
17 | extern unsigned int OPENSSL_ia32cap_P[4]; | |
18 | ||
19 | # if defined(OPENSSL_CPUID_OBJ) | |
20 | ||
21 | /* | |
22 | * Purpose of these minimalistic and character-type-agnostic subroutines | |
23 | * is to break dependency on MSVCRT (on Windows) and locale. This makes | |
24 | * OPENSSL_cpuid_setup safe to use as "constructor". "Character-type- | |
25 | * agnostic" means that they work with either wide or 8-bit characters, | |
26 | * exploiting the fact that first 127 characters can be simply casted | |
27 | * between the sets, while the rest would be simply rejected by ossl_is* | |
28 | * subroutines. | |
29 | */ | |
30 | # ifdef _WIN32 | |
31 | typedef WCHAR variant_char; | |
32 | ||
33 | static variant_char *ossl_getenv(const char *name) | |
34 | { | |
35 | /* | |
36 | * Since we pull only one environment variable, it's simpler to | |
ad31628c | 37 | * just ignore |name| and use equivalent wide-char L-literal. |
ef83daf4 RL |
38 | * As well as to ignore excessively long values... |
39 | */ | |
40 | static WCHAR value[48]; | |
41 | DWORD len = GetEnvironmentVariableW(L"OPENSSL_ia32cap", value, 48); | |
42 | ||
43 | return (len > 0 && len < 48) ? value : NULL; | |
44 | } | |
45 | # else | |
46 | typedef char variant_char; | |
47 | # define ossl_getenv getenv | |
48 | # endif | |
49 | ||
50 | # include "crypto/ctype.h" | |
51 | ||
52 | static int todigit(variant_char c) | |
53 | { | |
54 | if (ossl_isdigit(c)) | |
55 | return c - '0'; | |
56 | else if (ossl_isxdigit(c)) | |
57 | return ossl_tolower(c) - 'a' + 10; | |
58 | ||
59 | /* return largest base value to make caller terminate the loop */ | |
60 | return 16; | |
61 | } | |
62 | ||
63 | static uint64_t ossl_strtouint64(const variant_char *str) | |
64 | { | |
65 | uint64_t ret = 0; | |
66 | unsigned int digit, base = 10; | |
67 | ||
68 | if (*str == '0') { | |
69 | base = 8, str++; | |
70 | if (ossl_tolower(*str) == 'x') | |
71 | base = 16, str++; | |
72 | } | |
73 | ||
1287dabd | 74 | while ((digit = todigit(*str++)) < base) |
ef83daf4 RL |
75 | ret = ret * base + digit; |
76 | ||
77 | return ret; | |
78 | } | |
79 | ||
80 | static variant_char *ossl_strchr(const variant_char *str, char srch) | |
81 | { variant_char c; | |
82 | ||
1287dabd | 83 | while ((c = *str)) { |
ef83daf4 RL |
84 | if (c == srch) |
85 | return (variant_char *)str; | |
86 | str++; | |
87 | } | |
88 | ||
89 | return NULL; | |
90 | } | |
91 | ||
92 | # define OPENSSL_CPUID_SETUP | |
93 | typedef uint64_t IA32CAP; | |
94 | ||
95 | void OPENSSL_cpuid_setup(void) | |
96 | { | |
97 | static int trigger = 0; | |
98 | IA32CAP OPENSSL_ia32_cpuid(unsigned int *); | |
99 | IA32CAP vec; | |
100 | const variant_char *env; | |
101 | ||
102 | if (trigger) | |
103 | return; | |
104 | ||
105 | trigger = 1; | |
106 | if ((env = ossl_getenv("OPENSSL_ia32cap")) != NULL) { | |
107 | int off = (env[0] == '~') ? 1 : 0; | |
108 | ||
109 | vec = ossl_strtouint64(env + off); | |
110 | ||
111 | if (off) { | |
112 | IA32CAP mask = vec; | |
113 | vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P) & ~mask; | |
114 | if (mask & (1<<24)) { | |
115 | /* | |
116 | * User disables FXSR bit, mask even other capabilities | |
117 | * that operate exclusively on XMM, so we don't have to | |
118 | * double-check all the time. We mask PCLMULQDQ, AMD XOP, | |
119 | * AES-NI and AVX. Formally speaking we don't have to | |
120 | * do it in x86_64 case, but we can safely assume that | |
121 | * x86_64 users won't actually flip this flag. | |
122 | */ | |
123 | vec &= ~((IA32CAP)(1<<1|1<<11|1<<25|1<<28) << 32); | |
124 | } | |
125 | } else if (env[0] == ':') { | |
126 | vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P); | |
127 | } | |
128 | ||
129 | if ((env = ossl_strchr(env, ':')) != NULL) { | |
130 | IA32CAP vecx; | |
131 | ||
132 | env++; | |
133 | off = (env[0] == '~') ? 1 : 0; | |
134 | vecx = ossl_strtouint64(env + off); | |
135 | if (off) { | |
136 | OPENSSL_ia32cap_P[2] &= ~(unsigned int)vecx; | |
137 | OPENSSL_ia32cap_P[3] &= ~(unsigned int)(vecx >> 32); | |
138 | } else { | |
139 | OPENSSL_ia32cap_P[2] = (unsigned int)vecx; | |
140 | OPENSSL_ia32cap_P[3] = (unsigned int)(vecx >> 32); | |
141 | } | |
142 | } else { | |
143 | OPENSSL_ia32cap_P[2] = 0; | |
144 | OPENSSL_ia32cap_P[3] = 0; | |
145 | } | |
146 | } else { | |
147 | vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P); | |
148 | } | |
149 | ||
150 | /* | |
151 | * |(1<<10) sets a reserved bit to signal that variable | |
152 | * was initialized already... This is to avoid interference | |
153 | * with cpuid snippets in ELF .init segment. | |
154 | */ | |
155 | OPENSSL_ia32cap_P[0] = (unsigned int)vec | (1 << 10); | |
156 | OPENSSL_ia32cap_P[1] = (unsigned int)(vec >> 32); | |
157 | } | |
158 | # else | |
159 | unsigned int OPENSSL_ia32cap_P[4]; | |
160 | # endif | |
161 | #endif | |
162 | ||
163 | #ifndef OPENSSL_CPUID_OBJ | |
164 | # ifndef OPENSSL_CPUID_SETUP | |
165 | void OPENSSL_cpuid_setup(void) | |
166 | { | |
167 | } | |
168 | # endif | |
169 | ||
170 | /* | |
171 | * The rest are functions that are defined in the same assembler files as | |
172 | * the CPUID functionality. | |
173 | */ | |
174 | ||
175 | /* | |
ad31628c | 176 | * The volatile is used to ensure that the compiler generates code that reads |
ef83daf4 RL |
177 | * all values from the array and doesn't try to optimize this away. The standard |
178 | * doesn't actually require this behavior if the original data pointed to is | |
179 | * not volatile, but compilers do this in practice anyway. | |
180 | * | |
181 | * There are also assembler versions of this function. | |
182 | */ | |
183 | # undef CRYPTO_memcmp | |
bbaeadb0 | 184 | int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len) |
ef83daf4 RL |
185 | { |
186 | size_t i; | |
187 | const volatile unsigned char *a = in_a; | |
188 | const volatile unsigned char *b = in_b; | |
189 | unsigned char x = 0; | |
190 | ||
191 | for (i = 0; i < len; i++) | |
192 | x |= a[i] ^ b[i]; | |
193 | ||
194 | return x; | |
195 | } | |
196 | ||
197 | /* | |
198 | * For systems that don't provide an instruction counter register or equivalent. | |
199 | */ | |
200 | uint32_t OPENSSL_rdtsc(void) | |
201 | { | |
202 | return 0; | |
203 | } | |
204 | ||
205 | size_t OPENSSL_instrument_bus(unsigned int *out, size_t cnt) | |
206 | { | |
207 | return 0; | |
208 | } | |
209 | ||
210 | size_t OPENSSL_instrument_bus2(unsigned int *out, size_t cnt, size_t max) | |
211 | { | |
212 | return 0; | |
213 | } | |
214 | #endif |