1 /* mpicoder.c  -  Coder for the external representation of MPIs
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
27 #include "mpi-internal.h"
32  * mpi_read_raw_data - Read a raw byte stream as a positive integer
46 		nbytes--;  in mpi_read_raw_data()
55 		nbits -= count_leading_zeros(buffer[0]) - (BITS_PER_LONG - 8);  in mpi_read_raw_data()
61 	val->nbits = nbits;  in mpi_read_raw_data()
62 	val->sign = 0;  in mpi_read_raw_data()
63 	val->nlimbs = nlimbs;  in mpi_read_raw_data()
66 		i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;  in mpi_read_raw_data()
68 		for (j = nlimbs; j > 0; j--) {  in mpi_read_raw_data()
75 			val->d[j - 1] = a;  in mpi_read_raw_data()
89 		return ERR_PTR(-EINVAL);  in mpi_read_from_buffer()
94 		return ERR_PTR(-EINVAL);  in mpi_read_from_buffer()
101 		return ERR_PTR(-EINVAL);  in mpi_read_from_buffer()
106 		return ERR_PTR(-ENOMEM);  in mpi_read_from_buffer()
118 	for (i = a->nlimbs - 1; i >= 0; i--) {  in count_lzeros()
119 		alimb = a->d[i];  in count_lzeros()
131  * mpi_read_buffer() - read MPI to a buffer provided by user (msb first)
133  * @a:		a multi precision integer
138  *		the data to-be-written on -EOVERFLOW in case buf_len was too
159 		return -EINVAL;  in mpi_read_buffer()
162 		*sign = a->sign;  in mpi_read_buffer()
166 	if (buf_len < n - lzeros) {  in mpi_read_buffer()
167 		*nbytes = n - lzeros;  in mpi_read_buffer()
168 		return -EOVERFLOW;  in mpi_read_buffer()
172 	*nbytes = n - lzeros;  in mpi_read_buffer()
174 	for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,  in mpi_read_buffer()
176 		i >= 0; i--) {  in mpi_read_buffer()
178 		alimb = cpu_to_be32(a->d[i]);  in mpi_read_buffer()
180 		alimb = cpu_to_be64(a->d[i]);  in mpi_read_buffer()
184 		memcpy(p, (u8 *)&alimb + lzeros, BYTES_PER_MPI_LIMB - lzeros);  in mpi_read_buffer()
185 		p += BYTES_PER_MPI_LIMB - lzeros;  in mpi_read_buffer()
193  * mpi_get_buffer() - Returns an allocated buffer with the MPI (msb first).
198  * @a:		a multi precision integer.
234  * mpi_write_to_sgl() - Funnction exports MPI to an sgl (msb first)
239  * @a:		a multi precision integer
265 		*sign = a->sign;  in mpi_write_to_sgl()
268 		return -EOVERFLOW;  in mpi_write_to_sgl()
272 		return -EINVAL;  in mpi_write_to_sgl()
280 		i = min_t(unsigned, nbytes - n, buf_len);  in mpi_write_to_sgl()
283 		nbytes -= i;  in mpi_write_to_sgl()
285 		buf_len -= i;  in mpi_write_to_sgl()
293 	for (i = a->nlimbs - 1; i >= 0; i--) {  in mpi_write_to_sgl()
295 		alimb = a->d[i] ? cpu_to_be32(a->d[i]) : 0;  in mpi_write_to_sgl()
297 		alimb = a->d[i] ? cpu_to_be64(a->d[i]) : 0;  in mpi_write_to_sgl()
305 			if (!--buf_len) {  in mpi_write_to_sgl()
319  * mpi_read_raw_from_sgl() - Function allocates an MPI and populates it with
352 			len--;  in mpi_read_raw_from_sgl()
363 		nbytes -= lzeros;  in mpi_read_raw_from_sgl()
369 	nbytes -= lzeros;  in mpi_read_raw_from_sgl()
378 		nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8);  in mpi_read_raw_from_sgl()
387 	val->nbits = nbits;  in mpi_read_raw_from_sgl()
388 	val->sign = 0;  in mpi_read_raw_from_sgl()
389 	val->nlimbs = nlimbs;  in mpi_read_raw_from_sgl()
394 	j = nlimbs - 1;  in mpi_read_raw_from_sgl()
396 	z = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;  in mpi_read_raw_from_sgl()
402 		nbytes -= len;  in mpi_read_raw_from_sgl()
408 				val->d[j--] = a;  in mpi_read_raw_from_sgl()