33 lines
832 B
C
33 lines
832 B
C
/*
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* (c) Copyright 2018 by Coinkite Inc. This file is covered by license found in COPYING-CC.
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*/
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#pragma once
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#include <stdbool.h>
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#include <stdint.h>
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//
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// Constant-time functions, useful for crypto checking.
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//
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// Ironically not constant-time anymore, but the delay is NOT data-dependant so same idea.
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//
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// Return T if all bytes are 0xff
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bool check_all_ones(const void *ptrV, int len);
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bool check_all_ones_raw(const void *ptrV, int len); // excludes delay
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// Return T if all bytes are 0x00
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bool check_all_zeros(const void *ptrV, int len);
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// Equality check.
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bool check_equal(const void *aV, const void *bV, int len);
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// XOR-mixin more bytes; acc = acc XOR more for each byte
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void static inline xor_mixin(uint8_t *acc, const uint8_t *more, int len)
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{
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for(; len; len--, more++, acc++) {
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*(acc) ^= *(more);
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}
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}
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