Files
SDK_SG200x_V2/fsbl/lib/libtommath/bn_mp_fread.c
carbon 0545e9dc6d init version 2024-05-07
commit d1edce71135cc6d98c0a4b5729774542b676e769
Author: sophgo-forum-service <forum_service@sophgo.com>
Date:   Fri Mar 15 16:07:33 2024 +0800

    [fix] recommend using ssh method to clone repo.
    [fix] fix sensor driver repo branch name.
2024-05-07 19:36:36 +08:00

69 lines
1.5 KiB
C

#include "tommath_private.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.
*
* SPDX-License-Identifier: Unlicense
*/
#ifndef LTM_NO_FILE
/* read a bigint from a file stream in ASCII */
int mp_fread(mp_int *a, int radix, FILE *stream)
{
int err, ch, neg, y;
unsigned pos;
/* clear a */
mp_zero(a);
/* if first digit is - then set negative */
ch = fgetc(stream);
if (ch == (int)'-') {
neg = MP_NEG;
ch = fgetc(stream);
} else {
neg = MP_ZPOS;
}
for (;;) {
pos = (unsigned)(ch - (int)'(');
if (mp_s_rmap_reverse_sz < pos) {
break;
}
y = (int)mp_s_rmap_reverse[pos];
if ((y == 0xff) || (y >= radix)) {
break;
}
/* shift up and add */
if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {
return err;
}
if ((err = mp_add_d(a, (mp_digit)y, a)) != MP_OKAY) {
return err;
}
ch = fgetc(stream);
}
if (mp_cmp_d(a, 0uL) != MP_EQ) {
a->sign = neg;
}
return MP_OKAY;
}
#endif
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */