lib/mpi/mpiutil.c

   1 /* mpiutil.ac  -  Utility functions for MPI
   2  * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20
  21 #include "mpi-internal.h"
  22
  23 /****************
  24  * Note:  It was a bad idea to use the number of limbs to allocate
  25  *        because on a alpha the limbs are large but we normally need
  26  *        integers of n bits - So we should chnage this to bits (or bytes).
  27  *
  28  *        But mpi_alloc is used in a lot of places :-)
  29  */
  30 MPI mpi_alloc(unsigned nlimbs)
  31 {
  32         MPI a;
  33
  34         a = kmalloc(sizeof *a, GFP_KERNEL);
  35         if (!a)
  36                 return a;
  37
  38         if (nlimbs) {
  39                 a->d = mpi_alloc_limb_space(nlimbs);
  40                 if (!a->d) {
  41                         kfree(a);
  42                         return NULL;
  43                 }
  44         } else {
  45                 a->d = NULL;
  46         }
  47
  48         a->alloced = nlimbs;
  49         a->nlimbs = 0;
  50         a->sign = 0;
  51         a->flags = 0;
  52         a->nbits = 0;
  53         return a;
  54 }
  55 EXPORT_SYMBOL_GPL(mpi_alloc);
  56
  57 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
  58 {
  59         size_t len = nlimbs * sizeof(mpi_limb_t);
  60
  61         if (!len)
  62                 return NULL;
  63
  64         return kmalloc(len, GFP_KERNEL);
  65 }
  66
  67 void mpi_free_limb_space(mpi_ptr_t a)
  68 {
  69         if (!a)
  70                 return;
  71
  72         kfree(a);
  73 }
  74
  75 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
  76 {
  77         mpi_free_limb_space(a->d);
  78         a->d = ap;
  79         a->alloced = nlimbs;
  80 }
  81
  82 /****************
  83  * Resize the array of A to NLIMBS. the additional space is cleared
  84  * (set to 0) [done by m_realloc()]
  85  */
  86 int mpi_resize(MPI a, unsigned nlimbs)
  87 {
  88         void *p;
  89
  90         if (nlimbs <= a->alloced)
  91                 return 0;       /* no need to do it */
  92
  93         if (a->d) {
  94                 p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
  95                 if (!p)
  96                         return -ENOMEM;
  97                 memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
  98                 kfree(a->d);
  99                 a->d = p;
 100         } else {
 101                 a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
 102                 if (!a->d)
 103                         return -ENOMEM;
 104         }
 105         a->alloced = nlimbs;
 106         return 0;
 107 }
 108
 109 void mpi_free(MPI a)
 110 {
 111         if (!a)
 112                 return;
 113
 114         if (a->flags & 4)
 115                 kfree(a->d);
 116         else
 117                 mpi_free_limb_space(a->d);
 118
 119         if (a->flags & ~7)
 120                 pr_info("invalid flag value in mpi\n");
 121         kfree(a);
 122 }
 123 EXPORT_SYMBOL_GPL(mpi_free);
 124
 125 MODULE_DESCRIPTION("Multiprecision maths library");
 126 MODULE_LICENSE("GPL");