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1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* | |
3 | * Cryptographic utilities | |
4 | * | |
5 | * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au> | |
6 | */ | |
7 | #ifndef _CRYPTO_UTILS_H | |
8 | #define _CRYPTO_UTILS_H | |
9 | ||
10 | #include <asm/unaligned.h> | |
11 | #include <linux/compiler_attributes.h> | |
12 | #include <linux/types.h> | |
13 | ||
14 | void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size); | |
15 | ||
16 | static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size) | |
17 | { | |
18 | if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && | |
19 | __builtin_constant_p(size) && | |
20 | (size % sizeof(unsigned long)) == 0) { | |
21 | unsigned long *d = (unsigned long *)dst; | |
22 | unsigned long *s = (unsigned long *)src; | |
23 | unsigned long l; | |
24 | ||
25 | while (size > 0) { | |
26 | l = get_unaligned(d) ^ get_unaligned(s++); | |
27 | put_unaligned(l, d++); | |
28 | size -= sizeof(unsigned long); | |
29 | } | |
30 | } else { | |
31 | __crypto_xor(dst, dst, src, size); | |
32 | } | |
33 | } | |
34 | ||
35 | static inline void crypto_xor_cpy(u8 *dst, const u8 *src1, const u8 *src2, | |
36 | unsigned int size) | |
37 | { | |
38 | if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && | |
39 | __builtin_constant_p(size) && | |
40 | (size % sizeof(unsigned long)) == 0) { | |
41 | unsigned long *d = (unsigned long *)dst; | |
42 | unsigned long *s1 = (unsigned long *)src1; | |
43 | unsigned long *s2 = (unsigned long *)src2; | |
44 | unsigned long l; | |
45 | ||
46 | while (size > 0) { | |
47 | l = get_unaligned(s1++) ^ get_unaligned(s2++); | |
48 | put_unaligned(l, d++); | |
49 | size -= sizeof(unsigned long); | |
50 | } | |
51 | } else { | |
52 | __crypto_xor(dst, src1, src2, size); | |
53 | } | |
54 | } | |
55 | ||
56 | noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size); | |
57 | ||
58 | /** | |
59 | * crypto_memneq - Compare two areas of memory without leaking | |
60 | * timing information. | |
61 | * | |
62 | * @a: One area of memory | |
63 | * @b: Another area of memory | |
64 | * @size: The size of the area. | |
65 | * | |
66 | * Returns 0 when data is equal, 1 otherwise. | |
67 | */ | |
68 | static inline int crypto_memneq(const void *a, const void *b, size_t size) | |
69 | { | |
70 | return __crypto_memneq(a, b, size) != 0UL ? 1 : 0; | |
71 | } | |
72 | ||
73 | #endif /* _CRYPTO_UTILS_H */ |