linux/include/linux/mpi.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* mpi.h  -  Multi Precision Integers
 *	Copyright (C) 1994, 1996, 1998, 1999,
 *                    2000, 2001 Free Software Foundation, Inc.
 *
 * This file is part of GNUPG.
 *
 * Note: This code is heavily based on the GNU MP Library.
 *	 Actually it's the same code with only minor changes in the
 *	 way the data is stored; this is to support the abstraction
 *	 of an optional secure memory allocation which may be used
 *	 to avoid revealing of sensitive data due to paging etc.
 *	 The GNU MP Library itself is published under the LGPL;
 *	 however I decided to publish this code under the plain GPL.
 */

#ifndef G10_MPI_H
#define G10_MPI_H

#include <linux/types.h>
#include <linux/scatterlist.h>

#define BYTES_PER_MPI_LIMB …
#define BITS_PER_MPI_LIMB …

mpi_limb_t;
mpi_limb_signed_t;

struct gcry_mpi { … };

MPI;

#define mpi_get_nlimbs(a) …
#define mpi_has_sign(a) …

/*-- mpiutil.c --*/
MPI mpi_alloc(unsigned nlimbs);
void mpi_clear(MPI a);
void mpi_free(MPI a);
int mpi_resize(MPI a, unsigned nlimbs);

static inline MPI mpi_new(unsigned int nbits)
{ … }

MPI mpi_copy(MPI a);
MPI mpi_alloc_like(MPI a);
void mpi_snatch(MPI w, MPI u);
MPI mpi_set(MPI w, MPI u);
MPI mpi_set_ui(MPI w, unsigned long u);
MPI mpi_alloc_set_ui(unsigned long u);
void mpi_swap_cond(MPI a, MPI b, unsigned long swap);

/* Constants used to return constant MPIs.  See mpi_init if you
 * want to add more constants.
 */
#define MPI_NUMBER_OF_CONSTANTS …
enum gcry_mpi_constants { … };

MPI mpi_const(enum gcry_mpi_constants no);

/*-- mpicoder.c --*/

/* Different formats of external big integer representation. */
enum gcry_mpi_format { … };

MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
int mpi_fromstr(MPI val, const char *str);
MPI mpi_scanval(const char *string);
MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len);
void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
		    int *sign);
int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes,
		     int *sign);
int mpi_print(enum gcry_mpi_format format, unsigned char *buffer,
			size_t buflen, size_t *nwritten, MPI a);

/*-- mpi-mod.c --*/
void mpi_mod(MPI rem, MPI dividend, MPI divisor);

/* Context used with Barrett reduction.  */
struct barrett_ctx_s;
mpi_barrett_t;

mpi_barrett_t mpi_barrett_init(MPI m, int copy);
void mpi_barrett_free(mpi_barrett_t ctx);
void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx);
void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx);

/*-- mpi-pow.c --*/
int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);

/*-- mpi-cmp.c --*/
int mpi_cmp_ui(MPI u, ulong v);
int mpi_cmp(MPI u, MPI v);
int mpi_cmpabs(MPI u, MPI v);

/*-- mpi-sub-ui.c --*/
int mpi_sub_ui(MPI w, MPI u, unsigned long vval);

/*-- mpi-bit.c --*/
void mpi_normalize(MPI a);
unsigned mpi_get_nbits(MPI a);
int mpi_test_bit(MPI a, unsigned int n);
void mpi_set_bit(MPI a, unsigned int n);
void mpi_set_highbit(MPI a, unsigned int n);
void mpi_clear_highbit(MPI a, unsigned int n);
void mpi_clear_bit(MPI a, unsigned int n);
void mpi_rshift_limbs(MPI a, unsigned int count);
void mpi_rshift(MPI x, MPI a, unsigned int n);
void mpi_lshift_limbs(MPI a, unsigned int count);
void mpi_lshift(MPI x, MPI a, unsigned int n);

/*-- mpi-add.c --*/
void mpi_add_ui(MPI w, MPI u, unsigned long v);
void mpi_add(MPI w, MPI u, MPI v);
void mpi_sub(MPI w, MPI u, MPI v);
void mpi_addm(MPI w, MPI u, MPI v, MPI m);
void mpi_subm(MPI w, MPI u, MPI v, MPI m);

/*-- mpi-mul.c --*/
void mpi_mul(MPI w, MPI u, MPI v);
void mpi_mulm(MPI w, MPI u, MPI v, MPI m);

/*-- mpi-div.c --*/
void mpi_tdiv_r(MPI rem, MPI num, MPI den);
void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor);
void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor);

/*-- mpi-inv.c --*/
int mpi_invm(MPI x, MPI a, MPI n);

/*-- ec.c --*/

/* Object to represent a point in projective coordinates */
struct gcry_mpi_point { … };

MPI_POINT;

/* Models describing an elliptic curve */
enum gcry_mpi_ec_models { … };

/* Dialects used with elliptic curves */
enum ecc_dialects { … };

/* This context is used with all our EC functions. */
struct mpi_ec_ctx { … };

void mpi_ec_init(struct mpi_ec_ctx *ctx, enum gcry_mpi_ec_models model,
			enum ecc_dialects dialect,
			int flags, MPI p, MPI a, MPI b);
void mpi_ec_deinit(struct mpi_ec_ctx *ctx);
MPI_POINT mpi_point_new(unsigned int nbits);
void mpi_point_release(MPI_POINT p);
void mpi_point_init(MPI_POINT p);
void mpi_point_free_parts(MPI_POINT p);
int mpi_ec_get_affine(MPI x, MPI y, MPI_POINT point, struct mpi_ec_ctx *ctx);
void mpi_ec_add_points(MPI_POINT result,
			MPI_POINT p1, MPI_POINT p2,
			struct mpi_ec_ctx *ctx);
void mpi_ec_mul_point(MPI_POINT result,
			MPI scalar, MPI_POINT point,
			struct mpi_ec_ctx *ctx);
int mpi_ec_curve_point(MPI_POINT point, struct mpi_ec_ctx *ctx);

/* inline functions */

/**
 * mpi_get_size() - returns max size required to store the number
 *
 * @a:	A multi precision integer for which we want to allocate a buffer
 *
 * Return: size required to store the number
 */
static inline unsigned int mpi_get_size(MPI a)
{ … }
#endif /*G10_MPI_H */