LXR linux/include/linux/mpi.h

   1/* mpi.h  -  Multi Precision Integers
   2 *      Copyright (C) 1994, 1996, 1998, 1999,
   3 *                    2000, 2001 Free Software Foundation, Inc.
   4 *
   5 * This file is part of GNUPG.
   6 *
   7 * GNUPG is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * GNUPG is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  20 *
  21 * Note: This code is heavily based on the GNU MP Library.
  22 *       Actually it's the same code with only minor changes in the
  23 *       way the data is stored; this is to support the abstraction
  24 *       of an optional secure memory allocation which may be used
  25 *       to avoid revealing of sensitive data due to paging etc.
  26 *       The GNU MP Library itself is published under the LGPL;
  27 *       however I decided to publish this code under the plain GPL.
  28 */
  29
  30#ifndef G10_MPI_H
  31#define G10_MPI_H
  32
  33#include <linux/types.h>
  34#include <linux/scatterlist.h>
  35
  36#define BYTES_PER_MPI_LIMB      (BITS_PER_LONG / 8)
  37#define BITS_PER_MPI_LIMB       BITS_PER_LONG
  38
  39typedef unsigned long int mpi_limb_t;
  40typedef signed long int mpi_limb_signed_t;
  41
  42struct gcry_mpi {
  43        int alloced;            /* array size (# of allocated limbs) */
  44        int nlimbs;             /* number of valid limbs */
  45        int nbits;              /* the real number of valid bits (info only) */
  46        int sign;               /* indicates a negative number */
  47        unsigned flags;         /* bit 0: array must be allocated in secure memory space */
  48        /* bit 1: not used */
  49        /* bit 2: the limb is a pointer to some m_alloced data */
  50        mpi_limb_t *d;          /* array with the limbs */
  51};
  52
  53typedef struct gcry_mpi *MPI;
  54
  55#define mpi_get_nlimbs(a)     ((a)->nlimbs)
  56
  57/*-- mpiutil.c --*/
  58MPI mpi_alloc(unsigned nlimbs);
  59void mpi_free(MPI a);
  60int mpi_resize(MPI a, unsigned nlimbs);
  61
  62/*-- mpicoder.c --*/
  63MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
  64MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
  65MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len);
  66void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
  67int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
  68                    int *sign);
  69int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes,
  70                     int *sign);
  71
  72/*-- mpi-pow.c --*/
  73int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
  74
  75/*-- mpi-cmp.c --*/
  76int mpi_cmp_ui(MPI u, ulong v);
  77int mpi_cmp(MPI u, MPI v);
  78
  79/*-- mpi-bit.c --*/
  80void mpi_normalize(MPI a);
  81unsigned mpi_get_nbits(MPI a);
  82
  83/* inline functions */
  84
  85/**
  86 * mpi_get_size() - returns max size required to store the number
  87 *
  88 * @a:  A multi precision integer for which we want to allocate a bufer
  89 *
  90 * Return: size required to store the number
  91 */
  92static inline unsigned int mpi_get_size(MPI a)
  93{
  94        return a->nlimbs * BYTES_PER_MPI_LIMB;
  95}
  96#endif /*G10_MPI_H */
  97