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   1 /* -*-c-*-
   2  *
   3  * $Id: mp-io.c,v 1.6 2002/10/20 01:12:31 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 1.6  2002/10/20 01:12:31  mdw
  34  * Two's complement I/O fixes.
  35  *
  36  * Revision 1.5  2002/10/06 22:52:50  mdw
  37  * Pile of changes for supporting two's complement properly.
  38  *
  39  * Revision 1.4  2000/06/17 11:45:09  mdw
  40  * Major memory management overhaul.  Added arena support.  Use the secure
  41  * arena for secret integers.  Replace and improve the MP management macros
  42  * (e.g., replace MP_MODIFY by MP_DEST).
  43  *
  44  * Revision 1.3  1999/11/21 22:13:02  mdw
  45  * Add mp version of MPX_BITS.
  46  *
  47  * Revision 1.2  1999/11/19 13:19:06  mdw
  48  * Set flags on results correctly.
  49  *
  50  * Revision 1.1  1999/11/17 18:02:16  mdw
  51  * New multiprecision integer arithmetic suite.
  52  *
  53  */
  54
  55 /*----- Header files ------------------------------------------------------*/
  56
  57 #include "mp.h"
  58
  59 /*----- Main code ---------------------------------------------------------*/
  60
  61 /* --- @mp_octets@ --- *
  62  *
  63  * Arguments:   @const mp *m@ = a multiprecision integer
  64  *
  65  * Returns:     The number of octets required to represent @m@.
  66  *
  67  * Use:         Calculates the external storage required for a multiprecision
  68  *              integer.
  69  */
  70
  71 size_t mp_octets(const mp *m)
  72 {
  73   size_t sz;
  74   MPX_OCTETS(sz, m->v, m->vl);
  75   return (sz);
  76 }
  77
  78 /* --- @mp_octets2c@ --- *
  79  *
  80  * Arguments:   @const mp *m@ = a multiprecision integer
  81  *
  82  * Returns:     The number of octets required to represent @m@.
  83  *
  84  * Use:         Calculates the external storage required for a multiprecision
  85  *              integer represented as two's complement.
  86  */
  87
  88 size_t mp_octets2c(const mp *m)
  89 {
  90   size_t sz;
  91   MPX_OCTETS2C(sz, m->v, m->vl);
  92   return (sz);
  93 }
  94
  95 /* --- @mp_bits@ --- *
  96  *
  97  * Arguments:   @const mp *m@ = a multiprecision integer
  98  *
  99  * Returns:     The number of bits required to represent @m@.
 100  *
 101  * Use:         Calculates the external storage required for a multiprecision
 102  *              integer.
 103  */
 104
 105 unsigned long mp_bits(const mp *m)
 106 {
 107   unsigned long bits;
 108   MPX_BITS(bits, m->v, m->vl);
 109   return (bits);
 110 }
 111
 112 /* --- @mp_loadl@ --- *
 113  *
 114  * Arguments:   @mp *d@ = destination
 115  *              @const void *pv@ = pointer to source data
 116  *              @size_t sz@ = size of the source data
 117  *
 118  * Returns:     Resulting multiprecision number.
 119  *
 120  * Use:         Loads a multiprecision number from an array of octets.  The
 121  *              first byte in the array is the least significant.  More
 122  *              formally, if the bytes are %$b_0, b_1, \ldots, b_{n-1}$%
 123  *              then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%.
 124  */
 125
 126 mp *mp_loadl(mp *d, const void *pv, size_t sz)
 127 {
 128   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 129   mpx_loadl(d->v, d->vl, pv, sz);
 130   d->f &= ~(MP_UNDEF | MP_NEG);
 131   mp_shrink(d);
 132   return (d);
 133 }
 134
 135 /* --- @mp_storel@ --- *
 136  *
 137  * Arguments:   @const mp *m@ = source
 138  *              @void *pv@ = pointer to output array
 139  *              @size_t sz@ = size of the output array
 140  *
 141  * Returns:     ---
 142  *
 143  * Use:         Stores a multiprecision number in an array of octets.  The
 144  *              first byte in the array is the least significant.  If the
 145  *              array is too small to represent the number, high-order bits
 146  *              are truncated; if the array is too large, high order bytes
 147  *              are filled with zeros.  More formally, if the number is
 148  *              %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%,
 149  *              then the array is %$b_0, b_1, \ldots, b_{n-1}$%.
 150  */
 151
 152 void mp_storel(const mp *m, void *pv, size_t sz)
 153 {
 154   mpx_storel(m->v, m->vl, pv, sz);
 155 }
 156
 157 /* --- @mp_loadb@ --- *
 158  *
 159  * Arguments:   @mp *d@ = destination
 160  *              @const void *pv@ = pointer to source data
 161  *              @size_t sz@ = size of the source data
 162  *
 163  * Returns:     Resulting multiprecision number.
 164  *
 165  * Use:         Loads a multiprecision number from an array of octets.  The
 166  *              last byte in the array is the least significant.  More
 167  *              formally, if the bytes are %$b_{n-1}, b_{n-2}, \ldots, b_0$%
 168  *              then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%.
 169  */
 170
 171 mp *mp_loadb(mp *d, const void *pv, size_t sz)
 172 {
 173   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 174   mpx_loadb(d->v, d->vl, pv, sz);
 175   d->f &= ~(MP_UNDEF | MP_NEG);
 176   mp_shrink(d);
 177   return (d);
 178 }
 179
 180 /* --- @mp_storeb@ --- *
 181  *
 182  * Arguments:   @const mp *m@ = source
 183  *              @void *pv@ = pointer to output array
 184  *              @size_t sz@ = size of the output array
 185  *
 186  * Returns:     ---
 187  *
 188  * Use:         Stores a multiprecision number in an array of octets.  The
 189  *              last byte in the array is the least significant.  If the
 190  *              array is too small to represent the number, high-order bits
 191  *              are truncated; if the array is too large, high order bytes
 192  *              are filled with zeros.  More formally, if the number is
 193  *              %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%,
 194  *              then the array is %$b_{n-1}, b_{n-2}, \ldots, b_0$%.
 195  */
 196
 197 void mp_storeb(const mp *m, void *pv, size_t sz)
 198 {
 199   mpx_storeb(m->v, m->vl, pv, sz);
 200 }
 201
 202 /* --- @mp_loadl2c@ --- *
 203  *
 204  * Arguments:   @mp *d@ = destination
 205  *              @const void *pv@ = pointer to source data
 206  *              @size_t sz@ = size of the source data
 207  *
 208  * Returns:     Resulting multiprecision number.
 209  *
 210  * Use:         Loads a multiprecision number from an array of octets as
 211  *              two's complement.  The first byte in the array is the least
 212  *              significant.
 213  */
 214
 215 mp *mp_loadl2c(mp *d, const void *pv, size_t sz)
 216 {
 217   const octet *ov = pv;
 218   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 219   if (!sz || !(ov[sz - 1] & 0x80)) {
 220     mpx_loadl(d->v, d->vl, pv, sz);
 221     d->f &= ~MP_NEG;
 222   } else {
 223     mpx_loadl2cn(d->v, d->vl, pv, sz);
 224     d->f |= MP_NEG;
 225   }
 226   d->f &= ~MP_UNDEF;
 227   mp_shrink(d);
 228   return (d);
 229 }
 230
 231 /* --- @mp_storel2c@ --- *
 232  *
 233  * Arguments:   @const mp *m@ = source
 234  *              @void *pv@ = pointer to output array
 235  *              @size_t sz@ = size of the output array
 236  *
 237  * Returns:     ---
 238  *
 239  * Use:         Stores a multiprecision number in an array of octets as two's
 240  *              complement.  The first byte in the array is the least
 241  *              significant.  If the array is too small to represent the
 242  *              number, high-order bits are truncated; if the array is too
 243  *              large, high order bytes are sign-extended.
 244  */
 245
 246 void mp_storel2c(const mp *m, void *pv, size_t sz)
 247 {
 248   if (m->f & MP_NEG)
 249     mpx_storel2cn(m->v, m->vl, pv, sz);
 250   else
 251     mpx_storel(m->v, m->vl, pv, sz);
 252 }
 253
 254 /* --- @mp_loadb2c@ --- *
 255  *
 256  * Arguments:   @mp *d@ = destination
 257  *              @const void *pv@ = pointer to source data
 258  *              @size_t sz@ = size of the source data
 259  *
 260  * Returns:     Resulting multiprecision number.
 261  *
 262  * Use:         Loads a multiprecision number from an array of octets as
 263  *              two's complement.  The last byte in the array is the least
 264  *              significant.
 265  */
 266
 267 mp *mp_loadb2c(mp *d, const void *pv, size_t sz)
 268 {
 269   const octet *ov = pv;
 270   MP_DEST(d, MPW_RQ(sz), MP_UNDEF);
 271   if (!sz || !(ov[0] & 0x80)) {
 272     mpx_loadb(d->v, d->vl, pv, sz);
 273     d->f &= ~MP_NEG;
 274   } else {
 275     mpx_loadb2cn(d->v, d->vl, pv, sz);
 276     d->f |= MP_NEG;
 277   }
 278   d->f &= ~MP_UNDEF;
 279   mp_shrink(d);
 280   return (d);
 281 }
 282
 283 /* --- @mp_storeb2c@ --- *
 284  *
 285  * Arguments:   @const mp *m@ = source
 286  *              @void *pv@ = pointer to output array
 287  *              @size_t sz@ = size of the output array
 288  *
 289  * Returns:     ---
 290  *
 291  * Use:         Stores a multiprecision number in an array of octets, as
 292  *              two's complement.  The last byte in the array is the least
 293  *              significant.  If the array is too small to represent the
 294  *              number, high-order bits are truncated; if the array is too
 295  *              large, high order bytes are sign-extended.
 296  */
 297
 298 void mp_storeb2c(const mp *m, void *pv, size_t sz)
 299 {
 300   if (m->f & MP_NEG)
 301     mpx_storeb2cn(m->v, m->vl, pv, sz);
 302   else
 303     mpx_storeb(m->v, m->vl, pv, sz);
 304 }
 305
 306 /*----- That's all, folks -------------------------------------------------*/