/* mpicoder.c - Coder for the external representation of MPIs * Copyright (C) 1998, 1999 Free Software Foundation, Inc. * * This file is part of GnuPG. * * GnuPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * GnuPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #include <linux/bitops.h> #include <linux/count_zeros.h> #include <linux/byteorder/generic.h> #include <linux/scatterlist.h> #include <linux/string.h> #include "mpi-internal.h" #define MAX_EXTERN_SCAN_BYTES … #define MAX_EXTERN_MPI_BITS … /** * mpi_read_raw_data - Read a raw byte stream as a positive integer * @xbuffer: The data to read * @nbytes: The amount of data to read */ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) { … } EXPORT_SYMBOL_GPL(…); MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) { … } EXPORT_SYMBOL_GPL(…); /**************** * Fill the mpi VAL from the hex string in STR. */ int mpi_fromstr(MPI val, const char *str) { … } EXPORT_SYMBOL_GPL(…); MPI mpi_scanval(const char *string) { … } EXPORT_SYMBOL_GPL(…); static int count_lzeros(MPI a) { … } /** * mpi_read_buffer() - read MPI to a buffer provided by user (msb first) * * @a: a multi precision integer * @buf: buffer to which the output will be written to. Needs to be at * least mpi_get_size(a) long. * @buf_len: size of the buf. * @nbytes: receives the actual length of the data written on success and * the data to-be-written on -EOVERFLOW in case buf_len was too * small. * @sign: if not NULL, it will be set to the sign of a. * * Return: 0 on success or error code in case of error */ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, int *sign) { … } EXPORT_SYMBOL_GPL(…); /* * mpi_get_buffer() - Returns an allocated buffer with the MPI (msb first). * Caller must free the return string. * This function does return a 0 byte buffer with nbytes set to zero if the * value of A is zero. * * @a: a multi precision integer. * @nbytes: receives the length of this buffer. * @sign: if not NULL, it will be set to the sign of the a. * * Return: Pointer to MPI buffer or NULL on error */ void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) { … } EXPORT_SYMBOL_GPL(…); /** * mpi_write_to_sgl() - Funnction exports MPI to an sgl (msb first) * * This function works in the same way as the mpi_read_buffer, but it * takes an sgl instead of u8 * buf. * * @a: a multi precision integer * @sgl: scatterlist to write to. Needs to be at least * mpi_get_size(a) long. * @nbytes: the number of bytes to write. Leading bytes will be * filled with zero. * @sign: if not NULL, it will be set to the sign of a. * * Return: 0 on success or error code in case of error */ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes, int *sign) { … } EXPORT_SYMBOL_GPL(…); /* * mpi_read_raw_from_sgl() - Function allocates an MPI and populates it with * data from the sgl * * This function works in the same way as the mpi_read_raw_data, but it * takes an sgl instead of void * buffer. i.e. it allocates * a new MPI and reads the content of the sgl to the MPI. * * @sgl: scatterlist to read from * @nbytes: number of bytes to read * * Return: Pointer to a new MPI or NULL on error */ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes) { … } EXPORT_SYMBOL_GPL(…); /* Perform a two's complement operation on buffer P of size N bytes. */ static void twocompl(unsigned char *p, unsigned int n) { … } int mpi_print(enum gcry_mpi_format format, unsigned char *buffer, size_t buflen, size_t *nwritten, MPI a) { … } EXPORT_SYMBOL_GPL(…);