1 /* $NetBSD: bn_mp_grow.c,v 1.1.1.2 2014/04/24 12:45:31 pettai Exp $ */ 2 3 #include <tommath.h> 4 #ifdef BN_MP_GROW_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@gmail.com, http://libtom.org 18 */ 19 20 /* grow as required */ mp_grow(mp_int * a,int size)21int mp_grow (mp_int * a, int size) 22 { 23 int i; 24 mp_digit *tmp; 25 26 /* if the alloc size is smaller alloc more ram */ 27 if (a->alloc < size) { 28 /* ensure there are always at least MP_PREC digits extra on top */ 29 size += (MP_PREC * 2) - (size % MP_PREC); 30 31 /* reallocate the array a->dp 32 * 33 * We store the return in a temporary variable 34 * in case the operation failed we don't want 35 * to overwrite the dp member of a. 36 */ 37 tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size); 38 if (tmp == NULL) { 39 /* reallocation failed but "a" is still valid [can be freed] */ 40 return MP_MEM; 41 } 42 43 /* reallocation succeeded so set a->dp */ 44 a->dp = tmp; 45 46 /* zero excess digits */ 47 i = a->alloc; 48 a->alloc = size; 49 for (; i < a->alloc; i++) { 50 a->dp[i] = 0; 51 } 52 } 53 return MP_OKAY; 54 } 55 #endif 56 57 /* Source: /cvs/libtom/libtommath/bn_mp_grow.c,v */ 58 /* Revision: 1.4 */ 59 /* Date: 2006/12/28 01:25:13 */ 60