Mercurial > dropbear

annotate bn_mp_reduce_setup.c @ 142:d29b64170cf0 libtommath-orig

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
import of libtommath 0.32
author Matt Johnston <matt@ucc.asn.au>
date Sun, 19 Dec 2004 11:33:56 +0000
parents 86e0b50a9b58
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
142
d29b64170cf0 import of libtommath 0.32
Matt Johnston <matt@ucc.asn.au>
parents: 2
diff changeset
1 #include <tommath.h>
d29b64170cf0 import of libtommath 0.32
Matt Johnston <matt@ucc.asn.au>
parents: 2
diff changeset
2 #ifdef BN_MP_REDUCE_SETUP_C
2
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 *
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 * LibTomMath is a library that provides multiple-precision
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * integer arithmetic as well as number theoretic functionality.
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 *
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 * The library was designed directly after the MPI library by
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9 * Michael Fromberger but has been written from scratch with
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 * additional optimizations in place.
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 *
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12 * The library is free for all purposes without any express
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 * guarantee it works.
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 *
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 * Tom St Denis, [email protected], http://math.libtomcrypt.org
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 */
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 /* pre-calculate the value required for Barrett reduction
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 * For a given modulus "b" it calulates the value required in "a"
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 */
142
d29b64170cf0 import of libtommath 0.32
Matt Johnston <matt@ucc.asn.au>
parents: 2
diff changeset
21 int mp_reduce_setup (mp_int * a, mp_int * b)
2
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22 {
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 int res;
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) {
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26 return res;
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 }
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 return mp_div (a, b, a, NULL);
86e0b50a9b58 ltm 0.30 orig import
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 }
142
d29b64170cf0 import of libtommath 0.32
Matt Johnston <matt@ucc.asn.au>
parents: 2
diff changeset
30 #endif