comparison bn_mp_to_unsigned_bin.c @ 282:91fbc376f010 libtommath-orig libtommath-0.35

Import of libtommath 0.35 From ltm-0.35.tar.bz2 SHA1 of 3f193dbae9351e92d02530994fa18236f7fde01c
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:16:18 +0000
parents
children 97db060d0ef5
comparison
equal deleted inserted replaced
-1:000000000000 282:91fbc376f010
1 #include <tommath.h>
2 #ifdef BN_MP_TO_UNSIGNED_BIN_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 *
5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality.
7 *
8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
11 *
12 * The library is free for all purposes without any express
13 * guarantee it works.
14 *
15 * Tom St Denis, [email protected], http://math.libtomcrypt.org
16 */
17
18 /* store in unsigned [big endian] format */
19 int mp_to_unsigned_bin (mp_int * a, unsigned char *b)
20 {
21 int x, res;
22 mp_int t;
23
24 if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
25 return res;
26 }
27
28 x = 0;
29 while (mp_iszero (&t) == 0) {
30 #ifndef MP_8BIT
31 b[x++] = (unsigned char) (t.dp[0] & 255);
32 #else
33 b[x++] = (unsigned char) (t.dp[0] | ((t.dp[1] & 0x01) << 7));
34 #endif
35 if ((res = mp_div_2d (&t, 8, &t, NULL)) != MP_OKAY) {
36 mp_clear (&t);
37 return res;
38 }
39 }
40 bn_reverse (b, x);
41 mp_clear (&t);
42 return MP_OKAY;
43 }
44 #endif