/*

* 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_PUBLIC_API(2,0) 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);

/**

* 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