mpi.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* mpi.h  -  Multi Precision Integers
  3 *	Copyright (C) 1994, 1996, 1998, 1999,
  4 *                    2000, 2001 Free Software Foundation, Inc.
  5 *
  6 * This file is part of GNUPG.
  7 *
  8 * Note: This code is heavily based on the GNU MP Library.
  9 *	 Actually it's the same code with only minor changes in the
 10 *	 way the data is stored; this is to support the abstraction
 11 *	 of an optional secure memory allocation which may be used
 12 *	 to avoid revealing of sensitive data due to paging etc.
 13 *	 The GNU MP Library itself is published under the LGPL;
 14 *	 however I decided to publish this code under the plain GPL.
 15 */
 16
 17#ifndef G10_MPI_H
 18#define G10_MPI_H
 19
 20#include <linux/types.h>
 21#include <linux/scatterlist.h>
 22
 23#define BYTES_PER_MPI_LIMB	(BITS_PER_LONG / 8)
 24#define BITS_PER_MPI_LIMB	BITS_PER_LONG
 25
 26typedef unsigned long int mpi_limb_t;
 27typedef signed long int mpi_limb_signed_t;
 28
 29struct gcry_mpi {
 30	int alloced;		/* array size (# of allocated limbs) */
 31	int nlimbs;		/* number of valid limbs */
 32	int nbits;		/* the real number of valid bits (info only) */
 33	int sign;		/* indicates a negative number */
 34	unsigned flags;		/* bit 0: array must be allocated in secure memory space */
 35	/* bit 1: not used */
 36	/* bit 2: the limb is a pointer to some m_alloced data */
 37	mpi_limb_t *d;		/* array with the limbs */
 38};
 39
 40typedef struct gcry_mpi *MPI;
 41
 42#define mpi_get_nlimbs(a)     ((a)->nlimbs)
 43
 44/*-- mpiutil.c --*/
 45MPI mpi_alloc(unsigned nlimbs);
 46void mpi_free(MPI a);
 47int mpi_resize(MPI a, unsigned nlimbs);
 48
 49MPI mpi_copy(MPI a);
 50
 51/*-- mpicoder.c --*/
 52MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
 53MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
 54MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len);
 55void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
 56int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
 57		    int *sign);
 58int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes,
 59		     int *sign);
 60
 61/*-- mpi-mod.c --*/
 62int mpi_mod(MPI rem, MPI dividend, MPI divisor);
 63
 64/*-- mpi-pow.c --*/
 65int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
 66
 67/*-- mpi-cmp.c --*/
 68int mpi_cmp_ui(MPI u, ulong v);
 69int mpi_cmp(MPI u, MPI v);
 70
 71/*-- mpi-sub-ui.c --*/
 72int mpi_sub_ui(MPI w, MPI u, unsigned long vval);
 73
 74/*-- mpi-bit.c --*/
 75void mpi_normalize(MPI a);
 76unsigned mpi_get_nbits(MPI a);
 77int mpi_test_bit(MPI a, unsigned int n);
 78int mpi_set_bit(MPI a, unsigned int n);
 79int mpi_rshift(MPI x, MPI a, unsigned int n);
 80
 81/*-- mpi-add.c --*/
 82int mpi_add(MPI w, MPI u, MPI v);
 83int mpi_sub(MPI w, MPI u, MPI v);
 84int mpi_addm(MPI w, MPI u, MPI v, MPI m);
 85int mpi_subm(MPI w, MPI u, MPI v, MPI m);
 86
 87/*-- mpi-mul.c --*/
 88int mpi_mul(MPI w, MPI u, MPI v);
 89int mpi_mulm(MPI w, MPI u, MPI v, MPI m);
 90
 91/*-- mpi-div.c --*/
 92int mpi_tdiv_r(MPI rem, MPI num, MPI den);
 93int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor);
 94
 95/* inline functions */
 96
 97/**
 98 * mpi_get_size() - returns max size required to store the number
 99 *
100 * @a:	A multi precision integer for which we want to allocate a buffer
101 *
102 * Return: size required to store the number
103 */
104static inline unsigned int mpi_get_size(MPI a)
105{
106	return a->nlimbs * BYTES_PER_MPI_LIMB;
107}
108#endif /*G10_MPI_H */