68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
#include <tommath.h>
|
|
#ifdef BN_MP_FREAD_C
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis
|
|
*
|
|
* LibTomMath is a library that provides multiple-precision
|
|
* integer arithmetic as well as number theoretic functionality.
|
|
*
|
|
* The library was designed directly after the MPI library by
|
|
* Michael Fromberger but has been written from scratch with
|
|
* additional optimizations in place.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*
|
|
* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
|
|
*/
|
|
|
|
/* read a bigint from a file stream in ASCII */
|
|
int mp_fread(mp_int *a, int radix, FILE *stream)
|
|
{
|
|
int err, ch, neg, y;
|
|
|
|
/* clear a */
|
|
mp_zero(a);
|
|
|
|
/* if first digit is - then set negative */
|
|
ch = fgetc(stream);
|
|
if (ch == '-') {
|
|
neg = MP_NEG;
|
|
ch = fgetc(stream);
|
|
} else {
|
|
neg = MP_ZPOS;
|
|
}
|
|
|
|
for (;;) {
|
|
/* find y in the radix map */
|
|
for (y = 0; y < radix; y++) {
|
|
if (mp_s_rmap[y] == ch) {
|
|
break;
|
|
}
|
|
}
|
|
if (y == radix) {
|
|
break;
|
|
}
|
|
|
|
/* shift up and add */
|
|
if ((err = mp_mul_d(a, radix, a)) != MP_OKAY) {
|
|
return err;
|
|
}
|
|
if ((err = mp_add_d(a, y, a)) != MP_OKAY) {
|
|
return err;
|
|
}
|
|
|
|
ch = fgetc(stream);
|
|
}
|
|
if (mp_cmp_d(a, 0) != MP_EQ) {
|
|
a->sign = neg;
|
|
}
|
|
|
|
return MP_OKAY;
|
|
}
|
|
|
|
#endif
|
|
|
|
/* $Source$ */
|
|
/* $Revision$ */
|
|
/* $Date$ */
|