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 26 typedef unsigned long int mpi_limb_t; 27 typedef signed long int mpi_limb_signed_t; 28 29 struct 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 40 typedef struct gcry_mpi *MPI; 41 42 #define mpi_get_nlimbs(a) ((a)->nlimbs) 43 44 /*-- mpiutil.c --*/ 45 MPI mpi_alloc(unsigned nlimbs); 46 void mpi_free(MPI a); 47 int mpi_resize(MPI a, unsigned nlimbs); 48 49 /*-- mpicoder.c --*/ 50 MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); 51 MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); 52 MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len); 53 void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign); 54 int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, 55 int *sign); 56 int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes, 57 int *sign); 58 59 /*-- mpi-pow.c --*/ 60 int mpi_powm(MPI res, MPI base, MPI exp, MPI mod); 61 62 /*-- mpi-cmp.c --*/ 63 int mpi_cmp_ui(MPI u, ulong v); 64 int mpi_cmp(MPI u, MPI v); 65 66 /*-- mpi-sub-ui.c --*/ 67 int mpi_sub_ui(MPI w, MPI u, unsigned long vval); 68 69 /*-- mpi-bit.c --*/ 70 void mpi_normalize(MPI a); 71 unsigned mpi_get_nbits(MPI a); 72 73 /* inline functions */ 74 75 /** 76 * mpi_get_size() - returns max size required to store the number 77 * 78 * @a: A multi precision integer for which we want to allocate a bufer 79 * 80 * Return: size required to store the number 81 */ 82 static inline unsigned int mpi_get_size(MPI a) 83 { 84 return a->nlimbs * BYTES_PER_MPI_LIMB; 85 } 86 #endif /*G10_MPI_H */ 87