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 39 typedef unsigned long int mpi_limb_t; 40 typedef signed long int mpi_limb_signed_t; 41 42 struct 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 53 typedef struct gcry_mpi *MPI; 54 55 #define mpi_get_nlimbs(a) ((a)->nlimbs) 56 57 /*-- mpiutil.c --*/ 58 MPI mpi_alloc(unsigned nlimbs); 59 void mpi_free(MPI a); 60 int mpi_resize(MPI a, unsigned nlimbs); 61 62 /*-- mpicoder.c --*/ 63 MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); 64 MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); 65 MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len); 66 void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign); 67 int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, 68 int *sign); 69 int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes, 70 int *sign); 71 72 /*-- mpi-pow.c --*/ 73 int mpi_powm(MPI res, MPI base, MPI exp, MPI mod); 74 75 /*-- mpi-cmp.c --*/ 76 int mpi_cmp_ui(MPI u, ulong v); 77 int mpi_cmp(MPI u, MPI v); 78 79 /*-- mpi-bit.c --*/ 80 void mpi_normalize(MPI a); 81 unsigned 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 */ 92 static inline unsigned int mpi_get_size(MPI a) 93 { 94 return a->nlimbs * BYTES_PER_MPI_LIMB; 95 } 96 #endif /*G10_MPI_H */ 97