/* -*-c-*-
*
- * $Id: mprand.c,v 1.2 1999/12/22 15:55:33 mdw Exp $
+ * $Id: mprand.c,v 1.4 2001/05/07 17:31:19 mdw Exp $
*
* Generate a random multiprecision integer
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mprand.c,v $
+ * Revision 1.4 2001/05/07 17:31:19 mdw
+ * Fix off-by one bug in mprand_range. Probably security critical: the old
+ * code generated numbers between zero and the highest power of 2 less than
+ * the given range.
+ *
+ * Revision 1.3 2000/06/17 11:45:09 mdw
+ * Major memory management overhaul. Added arena support. Use the secure
+ * arena for secret integers. Replace and improve the MP management macros
+ * (e.g., replace MP_MODIFY by MP_DEST).
+ *
* Revision 1.2 1999/12/22 15:55:33 mdw
* Modify `mprand' slightly. Add `mprand_range'.
*
mp *mprand(mp *d, unsigned b, grand *r, mpw or)
{
size_t sz = (b + 7) >> 3;
- octet *v = xmalloc(sz);
+ arena *a = (d && (d->f & MP_BURN)) ? arena_secure : arena_global;
+ octet *v = x_alloc(a, sz);
unsigned m;
/* --- Fill buffer with random data --- */
d = mp_loadb(d, v, sz);
d->v[0] |= or;
- free(v);
+ memset(v, 0, sz);
+ x_free(a, v);
return (d);
}
{
size_t b = mp_bits(l);
size_t sz = (b + 7) >> 3;
- octet *v = xmalloc(sz);
+ arena *a = (d && (d->f & MP_BURN)) ? arena_secure : arena_global;
+ octet *v = x_alloc(a, sz);
unsigned m;
/* --- The algorithm --- *
* As usual, the number of iterations expected is two.
*/
- b = (b - 1) & 7;
+ b = ((b - 1) & 7) + 1;
m = (1 << b) - 1;
do {
r->ops->fill(r, v, sz);
/* --- Done --- */
- free(v);
+ memset(v, 0, sz);
+ x_free(a, v);
return (d);
}