33 lines
954 B
C++
33 lines
954 B
C++
/**
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* Constant-time functions
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*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
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*/
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#ifndef MBEDTLS_CONSTANT_TIME_H
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#define MBEDTLS_CONSTANT_TIME_H
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#include <stddef.h>
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/** Constant-time buffer comparison without branches.
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*
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* This is equivalent to the standard memcmp function, but is likely to be
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* compiled to code using bitwise operation rather than a branch.
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*
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* This function can be used to write constant-time code by replacing branches
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* with bit operations using masks.
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*
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* \param a Pointer to the first buffer.
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* \param b Pointer to the second buffer.
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* \param n The number of bytes to compare in the buffer.
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*
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* \return Zero if the content of the two buffer is the same,
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* otherwise non-zero.
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*/
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int mbedtls_ct_memcmp(const void *a,
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const void *b,
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size_t n);
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#endif /* MBEDTLS_CONSTANT_TIME_H */
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