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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/*3 * Cryptographic utilities4 *5 * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>6 */7#ifndef _CRYPTO_UTILS_H8#define _CRYPTO_UTILS_H9 10#include <linux/unaligned.h>11#include <linux/compiler_attributes.h>12#include <linux/types.h>13 14void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size);15 16static 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 35static 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 56noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);57 58/**59 * crypto_memneq - Compare two areas of memory without leaking60 * timing information.61 *62 * @a: One area of memory63 * @b: Another area of memory64 * @size: The size of the area.65 *66 * Returns 0 when data is equal, 1 otherwise.67 */68static 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