git.distorted.org.uk Git - u/mdw/catacomb/blob - mp-io.c

   1 /* -*-c-*-
   2  *
   3  * $Id: mp-io.c,v 1.4 2000/06/17 11:45:09 mdw Exp $
   4  *
   5  * Loading and storing of multiprecision integers
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: mp-io.c,v $
  33  * Revision 1.4  2000/06/17 11:45:09  mdw
  34  * Major memory management overhaul.  Added arena support.  Use the secure
  35  * arena for secret integers.  Replace and improve the MP management macros
  36  * (e.g., replace MP_MODIFY by MP_DEST).
  37  *
  38  * Revision 1.3  1999/11/21 22:13:02  mdw
  39  * Add mp version of MPX_BITS.
  40  *
  41  * Revision 1.2  1999/11/19 13:19:06  mdw
  42  * Set flags on results correctly.
  43  *
  44  * Revision 1.1  1999/11/17 18:02:16  mdw
  45  * New multiprecision integer arithmetic suite.
  46  *
  47  */
  48
  49 /*----- Header files ------------------------------------------------------*/
  50
  51 #include "mp.h"
  52
  53 /*----- Main code ---------------------------------------------------------*/
  54
  55 /* --- @mp_octets@ --- *
  56  *
  57  * Arguments:   @const mp *m@ = a multiprecision integer
  58  *
  59  * Returns:     The number of octets required to represent @m@.
  60  *
  61  * Use:         Calculates the external storage required for a multiprecision
  62  *              integer.
  63  */
  64
  65 size_t mp_octets(const mp *m)
  66 {
  67   size_t sz;
  68   MPX_OCTETS(sz, m->v, m->vl);
  69   return (sz);
  70 }
  71
  72 /* --- @mp_bits@ --- *
  73  *
  74  * Arguments:   @const mp *m@ = a multiprecision integer
  75  *
  76  * Returns:     The number of bits required to represent @m@.
  77  *
  78  * Use:         Calculates the external storage required for a multiprecision
  79  *              integer.
  80  */
  81
  82 unsigned long mp_bits(const mp *m)
  83 {
  84   unsigned long bits;
  85   MPX_BITS(bits, m->v, m->vl);
  86   return (bits);
  87 }
  88
  89 /* --- @mp_loadl@ --- *
  90  *
  91  * Arguments:   @mp *d@ = destination
  92  *              @const void *pv@ = pointer to source data
  93  *              @size_t sz@ = size of the source data
  94  *
  95  * Returns:     Resulting multiprecision number.
  96  *
  97  * Use:         Loads a multiprecision number from an array of octets.  The
  98  *              first byte in the array is the least significant.  More
  99  *              formally, if the bytes are %$b_0, b_1, \ldots, b_{n-1}$%
 100  *              then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%.
 101  */
 102
 103 mp *mp_loadl(mp *d, const void *pv, size_t sz)
 104 {
 105   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 106   mpx_loadl(d->v, d->vl, pv, sz);
 107   d->f &= ~(MP_UNDEF | MP_NEG);
 108   mp_shrink(d);
 109   return (d);
 110 }
 111
 112 /* --- @mp_storel@ --- *
 113  *
 114  * Arguments:   @const mp *m@ = source
 115  *              @void *pv@ = pointer to output array
 116  *              @size_t sz@ = size of the output array
 117  *
 118  * Returns:     ---
 119  *
 120  * Use:         Stores a multiprecision number in an array of octets.  The
 121  *              first byte in the array is the least significant.  If the
 122  *              array is too small to represent the number, high-order bits
 123  *              are truncated; if the array is too large, high order bytes
 124  *              are filled with zeros.  More formally, if the number is
 125  *              %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%,
 126  *              then the array is %$b_0, b_1, \ldots, b_{n-1}$%.
 127  */
 128
 129 void mp_storel(const mp *m, void *pv, size_t sz)
 130 {
 131   mpx_storel(m->v, m->vl, pv, sz);
 132 }
 133
 134 /* --- @mp_loadb@ --- *
 135  *
 136  * Arguments:   @mp *d@ = destination
 137  *              @const void *pv@ = pointer to source data
 138  *              @size_t sz@ = size of the source data
 139  *
 140  * Returns:     Resulting multiprecision number.
 141  *
 142  * Use:         Loads a multiprecision number from an array of octets.  The
 143  *              last byte in the array is the least significant.  More
 144  *              formally, if the bytes are %$b_{n-1}, b_{n-2}, \ldots, b_0$%
 145  *              then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%.
 146  */
 147
 148 mp *mp_loadb(mp *d, const void *pv, size_t sz)
 149 {
 150   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 151   mpx_loadb(d->v, d->vl, pv, sz);
 152   d->f &= ~(MP_UNDEF | MP_NEG);
 153   mp_shrink(d);
 154   return (d);
 155 }
 156
 157 /* --- @mp_storeb@ --- *
 158  *
 159  * Arguments:   @const mp *m@ = source
 160  *              @void *pv@ = pointer to output array
 161  *              @size_t sz@ = size of the output array
 162  *
 163  * Returns:     ---
 164  *
 165  * Use:         Stores a multiprecision number in an array of octets.  The
 166  *              last byte in the array is the least significant.  If the
 167  *              array is too small to represent the number, high-order bits
 168  *              are truncated; if the array is too large, high order bytes
 169  *              are filled with zeros.  More formally, if the number is
 170  *              %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%,
 171  *              then the array is %$b_{n-1}, b_{n-2}, \ldots, b_0$%.
 172  */
 173
 174 void mp_storeb(const mp *m, void *pv, size_t sz)
 175 {
 176   mpx_storeb(m->v, m->vl, pv, sz);
 177 }
 178
 179 /*----- That's all, folks -------------------------------------------------*/