Mercurial > dropbear
annotate bn_mp_reduce_2k_setup.c @ 202:d7f5a681fa23 libtommath
Update Makefile.in for dropbear
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Wed, 11 May 2005 16:25:34 +0000 |
| parents | d8254fc979e9 |
| children |
| rev | line source |
|---|---|
| 142 | 1 #include <tommath.h> |
| 2 #ifdef BN_MP_REDUCE_2K_SETUP_C | |
| 2 | 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 /* determines the setup value */ | |
|
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d8254fc979e9
Initial import of libtommath 0.35
Matt Johnston <matt@ucc.asn.au>
parents:
142
diff
changeset
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19 int mp_reduce_2k_setup(mp_int *a, mp_digit *d) |
| 2 | 20 { |
| 21 int res, p; | |
| 22 mp_int tmp; | |
| 23 | |
| 24 if ((res = mp_init(&tmp)) != MP_OKAY) { | |
| 25 return res; | |
| 26 } | |
| 27 | |
| 28 p = mp_count_bits(a); | |
| 29 if ((res = mp_2expt(&tmp, p)) != MP_OKAY) { | |
| 30 mp_clear(&tmp); | |
| 31 return res; | |
| 32 } | |
| 33 | |
| 34 if ((res = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) { | |
| 35 mp_clear(&tmp); | |
| 36 return res; | |
| 37 } | |
| 38 | |
| 39 *d = tmp.dp[0]; | |
| 40 mp_clear(&tmp); | |
| 41 return MP_OKAY; | |
| 42 } | |
| 142 | 43 #endif |