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comparison libtommath/bn_mp_sqr.c @ 284:eed26cff980b

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propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583) to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:49 +0000
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children 5ff8218bcee9
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283:bd240aa12ba7 284:eed26cff980b
1 #include <tommath.h>
2 #ifdef BN_MP_SQR_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 /* computes b = a*a */
19 int
20 mp_sqr (mp_int * a, mp_int * b)
21 {
22 int res;
23
24 #ifdef BN_MP_TOOM_SQR_C
25 /* use Toom-Cook? */
26 if (a->used >= TOOM_SQR_CUTOFF) {
27 res = mp_toom_sqr(a, b);
28 /* Karatsuba? */
29 } else
30 #endif
31 #ifdef BN_MP_KARATSUBA_SQR_C
32 if (a->used >= KARATSUBA_SQR_CUTOFF) {
33 res = mp_karatsuba_sqr (a, b);
34 } else
35 #endif
36 {
37 #ifdef BN_FAST_S_MP_SQR_C
38 /* can we use the fast comba multiplier? */
39 if ((a->used * 2 + 1) < MP_WARRAY &&
40 a->used <
41 (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) {
42 res = fast_s_mp_sqr (a, b);
43 } else
44 #endif
45 #ifdef BN_S_MP_SQR_C
46 res = s_mp_sqr (a, b);
47 #else
48 res = MP_VAL;
49 #endif
50 }
51 b->sign = MP_ZPOS;
52 return res;
53 }
54 #endif