1f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#include <tommath.h> 2f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef BN_MP_GROW_C 3f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* LibTomMath, multiple-precision integer library -- Tom St Denis 4f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 5f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * LibTomMath is a library that provides multiple-precision 6f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * integer arithmetic as well as number theoretic functionality. 7f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 8f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * The library was designed directly after the MPI library by 9f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * Michael Fromberger but has been written from scratch with 10f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * additional optimizations in place. 11f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * The library is free for all purposes without any express 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * guarantee it works. 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project */ 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* grow as required */ 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint mp_grow (mp_int * a, int size) 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int i; 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project mp_digit *tmp; 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* if the alloc size is smaller alloc more ram */ 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (a->alloc < size) { 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* ensure there are always at least MP_PREC digits extra on top */ 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project size += (MP_PREC * 2) - (size % MP_PREC); 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* reallocate the array a->dp 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * We store the return in a temporary variable 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * in case the operation failed we don't want 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * to overwrite the dp member of a. 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project */ 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size); 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (tmp == NULL) { 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* reallocation failed but "a" is still valid [can be freed] */ 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return MP_MEM; 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* reallocation succeeded so set a->dp */ 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a->dp = tmp; 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* zero excess digits */ 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project i = a->alloc; 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a->alloc = size; 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project for (; i < a->alloc; i++) { 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project a->dp[i] = 0; 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 51f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return MP_OKAY; 52f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 53f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif 54f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 55f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtommath/bn_mp_grow.c,v $ */ 56f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.3 $ */ 57f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2006/03/31 14:18:44 $ */ 58