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, src1: dst, src2: 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 */ |
74 | |