projects
/
u
/
mdw
/
catacomb
/ blobdiff
commit
grep
author
committer
pickaxe
?
search:
re
summary
|
shortlog
|
log
|
commit
|
commitdiff
|
tree
raw
|
inline
| side by side
Add utility for computing conversion factors for ONBs. Fix up elliptic curve
[u/mdw/catacomb]
/
mpreduce.c
diff --git
a/mpreduce.c
b/mpreduce.c
index
7d31334
..
13e705e
100644
(file)
--- a/
mpreduce.c
+++ b/
mpreduce.c
@@
-1,6
+1,6
@@
/* -*-c-*-
*
/* -*-c-*-
*
- * $Id
: mpreduce.c,v 1.2 2004/04/08 01:36:15 mdw Exp
$
+ * $Id$
*
* Efficient reduction modulo nice primes
*
*
* Efficient reduction modulo nice primes
*
@@
-64,7
+64,7
@@
void mpreduce_create(mpreduce *r, mp *p)
/* --- Fill in the easy stuff --- */
/* --- Fill in the easy stuff --- */
- assert(MP_
ISPOS
(p));
+ assert(MP_
POSP
(p));
d = mp_bits(p);
r->lim = d/MPW_BITS;
r->s = d%MPW_BITS;
d = mp_bits(p);
r->lim = d/MPW_BITS;
r->s = d%MPW_BITS;
@@
-253,7
+253,7
@@
mp *mpreduce_do(mpreduce *r, mp *d, mp *x)
/* --- If source is negative, divide --- */
/* --- If source is negative, divide --- */
- if (MP_
ISNEG
(x)) {
+ if (MP_
NEGP
(x)) {
mp_div(0, &d, x, r->p);
return (d);
}
mp_div(0, &d, x, r->p);
return (d);
}
@@
-335,12
+335,18
@@
mp *mpreduce_exp(mpreduce *mr, mp *d, mp *a, mp *e)
mp *spare = (e->f & MP_BURN) ? MP_NEWSEC : MP_NEW;
MP_SHRINK(e);
mp *spare = (e->f & MP_BURN) ? MP_NEWSEC : MP_NEW;
MP_SHRINK(e);
- if (!MP_LEN(e))
+ MP_COPY(a);
+ if (MP_ZEROP(e))
;
;
- else if (MP_LEN(e) < EXP_THRESH)
- EXP_SIMPLE(x, a, e);
- else
- EXP_WINDOW(x, a, e);
+ else {
+ if (MP_NEGP(e))
+ a = mp_modinv(a, a, mr->p);
+ if (MP_LEN(e) < EXP_THRESH)
+ EXP_SIMPLE(x, a, e);
+ else
+ EXP_WINDOW(x, a, e);
+ }
+ mp_drop(a);
mp_drop(d);
mp_drop(spare);
return (x);
mp_drop(d);
mp_drop(spare);
return (x);