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/*
* Division
* (C) 1999-2007 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_DIVISON_ALGORITHM_H_
#define BOTAN_DIVISON_ALGORITHM_H_
#include <botan/bigint.h>
BOTAN_FUTURE_INTERNAL_HEADER(divide.h)
namespace Botan {
/**
* BigInt Division
* @param x an integer
* @param y a non-zero integer
* @param q will be set to x / y
* @param r will be set to x % y
*/
void BOTAN_UNSTABLE_API vartime_divide(const BigInt& x,
const BigInt& y,
BigInt& q,
BigInt& r);
/**
* BigInt division, const time variant
*
* This runs with control flow independent of the values of x/y.
* Warning: the loop bounds still leak the sizes of x and y.
*
* @param x an integer
* @param y a non-zero integer
* @param q will be set to x / y
* @param r will be set to x % y
*/
void BOTAN_PUBLIC_API(2,9) ct_divide(const BigInt& x,
const BigInt& y,
BigInt& q,
BigInt& r);
inline void divide(const BigInt& x,
const BigInt& y,
BigInt& q,
BigInt& r)
{
ct_divide(x, y, q, r);
}
/**
* BigInt division, const time variant
*
* This runs with control flow independent of the values of x/y.
* Warning: the loop bounds still leak the sizes of x and y.
*
* @param x an integer
* @param y a non-zero integer
* @return x/y with remainder discarded
*/
inline BigInt ct_divide(const BigInt& x, const BigInt& y)
{
BigInt q, r;
ct_divide(x, y, q, r);
return q;
}
/**
* BigInt division, const time variant
*
* This runs with control flow independent of the values of x/y.
* Warning: the loop bounds still leak the sizes of x and y.
*
* @param x an integer
* @param y a non-zero integer
* @param q will be set to x / y
* @param r will be set to x % y
*/
void BOTAN_PUBLIC_API(2,9) ct_divide_u8(const BigInt& x,
uint8_t y,
BigInt& q,
uint8_t& r);
/**
* BigInt modulo, const time variant
*
* Using this function is (slightly) cheaper than calling ct_divide and
* using only the remainder.
*
* @param x a non-negative integer
* @param modulo a positive integer
* @return result x % modulo
*/
BigInt BOTAN_PUBLIC_API(2,9) ct_modulo(const BigInt& x,
const BigInt& modulo);
}
#endif
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