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Diffstat (limited to 'lib/mpi/mpicoder.c')
-rw-r--r-- | lib/mpi/mpicoder.c | 415 |
1 files changed, 0 insertions, 415 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c deleted file mode 100644 index eead4b339466..000000000000 --- a/lib/mpi/mpicoder.c +++ /dev/null @@ -1,415 +0,0 @@ -/* 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_MPI_BITS 16384 - -/** - * 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) -{ - const uint8_t *buffer = xbuffer; - int i, j; - unsigned nbits, nlimbs; - mpi_limb_t a; - MPI val = NULL; - - while (nbytes > 0 && buffer[0] == 0) { - buffer++; - nbytes--; - } - - nbits = nbytes * 8; - if (nbits > MAX_EXTERN_MPI_BITS) { - pr_info("MPI: mpi too large (%u bits)\n", nbits); - return NULL; - } - if (nbytes > 0) - nbits -= count_leading_zeros(buffer[0]) - (BITS_PER_LONG - 8); - - nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); - val = mpi_alloc(nlimbs); - if (!val) - return NULL; - val->nbits = nbits; - val->sign = 0; - val->nlimbs = nlimbs; - - if (nbytes > 0) { - i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; - i %= BYTES_PER_MPI_LIMB; - for (j = nlimbs; j > 0; j--) { - a = 0; - for (; i < BYTES_PER_MPI_LIMB; i++) { - a <<= 8; - a |= *buffer++; - } - i = 0; - val->d[j - 1] = a; - } - } - return val; -} -EXPORT_SYMBOL_GPL(mpi_read_raw_data); - -MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) -{ - const uint8_t *buffer = xbuffer; - unsigned int nbits, nbytes; - MPI val; - - if (*ret_nread < 2) - return ERR_PTR(-EINVAL); - nbits = buffer[0] << 8 | buffer[1]; - - if (nbits > MAX_EXTERN_MPI_BITS) { - pr_info("MPI: mpi too large (%u bits)\n", nbits); - return ERR_PTR(-EINVAL); - } - - nbytes = DIV_ROUND_UP(nbits, 8); - if (nbytes + 2 > *ret_nread) { - pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", - nbytes, *ret_nread); - return ERR_PTR(-EINVAL); - } - - val = mpi_read_raw_data(buffer + 2, nbytes); - if (!val) - return ERR_PTR(-ENOMEM); - - *ret_nread = nbytes + 2; - return val; -} -EXPORT_SYMBOL_GPL(mpi_read_from_buffer); - -static int count_lzeros(MPI a) -{ - mpi_limb_t alimb; - int i, lzeros = 0; - - for (i = a->nlimbs - 1; i >= 0; i--) { - alimb = a->d[i]; - if (alimb == 0) { - lzeros += sizeof(mpi_limb_t); - } else { - lzeros += count_leading_zeros(alimb) / 8; - break; - } - } - return lzeros; -} - -/** - * mpi_read_buffer() - read MPI to a bufer provided by user (msb first) - * - * @a: a multi precision integer - * @buf: bufer to which the output will be written to. Needs to be at - * leaset 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) -{ - uint8_t *p; -#if BYTES_PER_MPI_LIMB == 4 - __be32 alimb; -#elif BYTES_PER_MPI_LIMB == 8 - __be64 alimb; -#else -#error please implement for this limb size. -#endif - unsigned int n = mpi_get_size(a); - int i, lzeros; - - if (!buf || !nbytes) - return -EINVAL; - - if (sign) - *sign = a->sign; - - lzeros = count_lzeros(a); - - if (buf_len < n - lzeros) { - *nbytes = n - lzeros; - return -EOVERFLOW; - } - - p = buf; - *nbytes = n - lzeros; - - for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB, - lzeros %= BYTES_PER_MPI_LIMB; - i >= 0; i--) { -#if BYTES_PER_MPI_LIMB == 4 - alimb = cpu_to_be32(a->d[i]); -#elif BYTES_PER_MPI_LIMB == 8 - alimb = cpu_to_be64(a->d[i]); -#else -#error please implement for this limb size. -#endif - memcpy(p, (u8 *)&alimb + lzeros, BYTES_PER_MPI_LIMB - lzeros); - p += BYTES_PER_MPI_LIMB - lzeros; - lzeros = 0; - } - return 0; -} -EXPORT_SYMBOL_GPL(mpi_read_buffer); - -/* - * 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) -{ - uint8_t *buf; - unsigned int n; - int ret; - - if (!nbytes) - return NULL; - - n = mpi_get_size(a); - - if (!n) - n++; - - buf = kmalloc(n, GFP_KERNEL); - - if (!buf) - return NULL; - - ret = mpi_read_buffer(a, buf, n, nbytes, sign); - - if (ret) { - kfree(buf); - return NULL; - } - return buf; -} -EXPORT_SYMBOL_GPL(mpi_get_buffer); - -/** - * 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) -{ - u8 *p, *p2; -#if BYTES_PER_MPI_LIMB == 4 - __be32 alimb; -#elif BYTES_PER_MPI_LIMB == 8 - __be64 alimb; -#else -#error please implement for this limb size. -#endif - unsigned int n = mpi_get_size(a); - struct sg_mapping_iter miter; - int i, x, buf_len; - int nents; - - if (sign) - *sign = a->sign; - - if (nbytes < n) - return -EOVERFLOW; - - nents = sg_nents_for_len(sgl, nbytes); - if (nents < 0) - return -EINVAL; - - sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC | SG_MITER_TO_SG); - sg_miter_next(&miter); - buf_len = miter.length; - p2 = miter.addr; - - while (nbytes > n) { - i = min_t(unsigned, nbytes - n, buf_len); - memset(p2, 0, i); - p2 += i; - nbytes -= i; - - buf_len -= i; - if (!buf_len) { - sg_miter_next(&miter); - buf_len = miter.length; - p2 = miter.addr; - } - } - - for (i = a->nlimbs - 1; i >= 0; i--) { -#if BYTES_PER_MPI_LIMB == 4 - alimb = a->d[i] ? cpu_to_be32(a->d[i]) : 0; -#elif BYTES_PER_MPI_LIMB == 8 - alimb = a->d[i] ? cpu_to_be64(a->d[i]) : 0; -#else -#error please implement for this limb size. -#endif - p = (u8 *)&alimb; - - for (x = 0; x < sizeof(alimb); x++) { - *p2++ = *p++; - if (!--buf_len) { - sg_miter_next(&miter); - buf_len = miter.length; - p2 = miter.addr; - } - } - } - - sg_miter_stop(&miter); - return 0; -} -EXPORT_SYMBOL_GPL(mpi_write_to_sgl); - -/* - * 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) -{ - struct sg_mapping_iter miter; - unsigned int nbits, nlimbs; - int x, j, z, lzeros, ents; - unsigned int len; - const u8 *buff; - mpi_limb_t a; - MPI val = NULL; - - ents = sg_nents_for_len(sgl, nbytes); - if (ents < 0) - return NULL; - - sg_miter_start(&miter, sgl, ents, SG_MITER_ATOMIC | SG_MITER_FROM_SG); - - lzeros = 0; - len = 0; - while (nbytes > 0) { - while (len && !*buff) { - lzeros++; - len--; - buff++; - } - - if (len && *buff) - break; - - sg_miter_next(&miter); - buff = miter.addr; - len = miter.length; - - nbytes -= lzeros; - lzeros = 0; - } - - miter.consumed = lzeros; - - nbytes -= lzeros; - nbits = nbytes * 8; - if (nbits > MAX_EXTERN_MPI_BITS) { - sg_miter_stop(&miter); - pr_info("MPI: mpi too large (%u bits)\n", nbits); - return NULL; - } - - if (nbytes > 0) - nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8); - - sg_miter_stop(&miter); - - nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); - val = mpi_alloc(nlimbs); - if (!val) - return NULL; - - val->nbits = nbits; - val->sign = 0; - val->nlimbs = nlimbs; - - if (nbytes == 0) - return val; - - j = nlimbs - 1; - a = 0; - z = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; - z %= BYTES_PER_MPI_LIMB; - - while (sg_miter_next(&miter)) { - buff = miter.addr; - len = miter.length; - - for (x = 0; x < len; x++) { - a <<= 8; - a |= *buff++; - if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) { - val->d[j--] = a; - a = 0; - } - } - z += x; - } - - return val; -} -EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl); |