/*
 * (c) Copyright 2018 by Coinkite Inc. This file is part of Coldcard <coldcardwallet.com>
 * and is covered by GPLv3 license found in COPYING.
 */
#pragma once
#include <stdbool.h>
#include <stdint.h>
//
// Constant-time functions, useful for crypto checking.
//

// Return T if all bytes are 0xff
bool check_all_ones(const void *ptrV, int len);

// Return T if all bytes are 0x00
bool check_all_zeros(const void *ptrV, int len);

// Equality check.
bool check_equal(const void *aV, const void *bV, int len);

// XOR-mixin more bytes; acc = acc XOR more for each byte
void static inline xor_mixin(uint8_t *acc, const uint8_t *more, int len)
{
	for(; len; len--, more++, acc++) {
		*(acc) ^= *(more);
	}
}