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      1 /*	$NetBSD: bn_mp_set_int.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
      2 
      3 #include <tommath.h>
      4 #ifdef BN_MP_SET_INT_C
      5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
      6  *
      7  * LibTomMath is a library that provides multiple-precision
      8  * integer arithmetic as well as number theoretic functionality.
      9  *
     10  * The library was designed directly after the MPI library by
     11  * Michael Fromberger but has been written from scratch with
     12  * additional optimizations in place.
     13  *
     14  * The library is free for all purposes without any express
     15  * guarantee it works.
     16  *
     17  * Tom St Denis, tomstdenis (at) gmail.com, http://libtom.org
     18  */
     19 
     20 /* set a 32-bit const */
     21 int mp_set_int (mp_int * a, unsigned long b)
     22 {
     23   int     x, res;
     24 
     25   mp_zero (a);
     26 
     27   /* set four bits at a time */
     28   for (x = 0; x < 8; x++) {
     29     /* shift the number up four bits */
     30     if ((res = mp_mul_2d (a, 4, a)) != MP_OKAY) {
     31       return res;
     32     }
     33 
     34     /* OR in the top four bits of the source */
     35     a->dp[0] |= (b >> 28) & 15;
     36 
     37     /* shift the source up to the next four bits */
     38     b <<= 4;
     39 
     40     /* ensure that digits are not clamped off */
     41     a->used += 1;
     42   }
     43   mp_clamp (a);
     44   return MP_OKAY;
     45 }
     46 #endif
     47 
     48 /* Source: /cvs/libtom/libtommath/bn_mp_set_int.c,v  */
     49 /* Revision: 1.4  */
     50 /* Date: 2006/12/28 01:25:13  */
     51