annotate bn_mp_init_size.c @ 1:22d5cf7d4b1a libtommath

Renaming branch
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:23:46 +0000
parents
children d29b64170cf0
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
1
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 /* LibTomMath, multiple-precision integer library -- Tom St Denis
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2 *
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 * LibTomMath is a library that provides multiple-precision
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 * integer arithmetic as well as number theoretic functionality.
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 *
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * The library was designed directly after the MPI library by
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 * Michael Fromberger but has been written from scratch with
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 * additional optimizations in place.
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9 *
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 * The library is free for all purposes without any express
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 * guarantee it works.
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12 *
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 * Tom St Denis, [email protected], http://math.libtomcrypt.org
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 */
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 #include <tommath.h>
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17 /* init an mp_init for a given size */
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 int mp_init_size (mp_int * a, int size)
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 {
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 /* pad size so there are always extra digits */
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 size += (MP_PREC * 2) - (size % MP_PREC);
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 /* alloc mem */
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 a->dp = OPT_CAST(mp_digit) XCALLOC (sizeof (mp_digit), size);
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 if (a->dp == NULL) {
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26 return MP_MEM;
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 }
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 a->used = 0;
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 a->alloc = size;
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30 a->sign = MP_ZPOS;
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32 return MP_OKAY;
22d5cf7d4b1a Renaming branch
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33 }