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