lib/hcrypto/libtommath/bn_mp_to_sbin.c

   1 #include "tommath_private.h"
   2 #ifdef BN_MP_TO_SBIN_C
   3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
   4 /* SPDX-License-Identifier: Unlicense */
   5
   6 /* store in signed [big endian] format */
   7 mp_err mp_to_sbin(const mp_int *a, unsigned char *buf, size_t maxlen, size_t *written)
   8 {
   9    mp_err err;
  10    if (maxlen == 0u) {
  11       return MP_BUF;
  12    }
  13    if ((err = mp_to_ubin(a, buf + 1, maxlen - 1u, written)) != MP_OKAY) {
  14       return err;
  15    }
  16    if (written != NULL) {
  17       (*written)++;
  18    }
  19    buf[0] = (a->sign == MP_ZPOS) ? (unsigned char)0 : (unsigned char)1;
  20    return MP_OKAY;
  21 }
  22 #endif