git.distorted.org.uk Git - u/mdw/catacomb/blob - field-parse.c

   1 /* -*-c-*-
   2  *
   3  * $Id: field-parse.c,v 1.2 2004/04/01 21:28:41 mdw Exp $
   4  *
   5  * Parse field descriptions
   6  *
   7  * (c) 2004 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: field-parse.c,v $
  33  * Revision 1.2  2004/04/01 21:28:41  mdw
  34  * Normal basis support (translates to poly basis internally).  Rewrite
  35  * EC and prime group table generators in awk, so that they can reuse data
  36  * for repeated constants.
  37  *
  38  * Revision 1.1  2004/03/27 17:54:11  mdw
  39  * Standard curves and curve checking.
  40  *
  41  */
  42
  43 /*----- Header files ------------------------------------------------------*/
  44
  45 #include "field.h"
  46
  47 /*----- Main code ---------------------------------------------------------*/
  48
  49 /* --- @field_parse@ --- *
  50  *
  51  * Arguments:   @qd_parse *qd@ = parser context
  52  *
  53  * Returns:     Field pointer if OK, or null.
  54  *
  55  * Use:         Parses a field description, which has the form
  56  *
  57  *                * `prime', `niceprime' or `binpoly'
  58  *                * an optional `:'
  59  *                * the field modulus
  60  */
  61
  62 field *field_parse(qd_parse *qd)
  63 {
  64   field *f = 0;
  65   mp *m = MP_NEW, *b = MP_NEW;
  66
  67   switch (qd_enum(qd, "prime,niceprime,binpoly,binnorm")) {
  68     case 0:
  69       qd_delim(qd, ':');
  70       if ((m = qd_getmp(qd)) == 0) goto done;
  71       f = field_prime(m);
  72       break;
  73     case 1:
  74       qd_delim(qd, ':');
  75       if ((m = qd_getmp(qd)) == 0) goto done;
  76       f = field_niceprime(m);
  77       break;
  78     case 2:
  79       qd_delim(qd, ':');
  80       if ((m = qd_getmp(qd)) == 0) goto done;
  81       f = field_binpoly(m);
  82       break;
  83     case 3:
  84       qd_delim(qd, ':');
  85       if ((m = qd_getmp(qd)) == 0) goto done;
  86       qd_delim(qd, ',');
  87       if ((b = qd_getmp(qd)) == 0) goto done;
  88       f = field_binnorm(m, b);
  89       break;
  90     default:
  91       f = 0;
  92       break;
  93   }
  94 done:
  95   mp_drop(m);
  96   mp_drop(b);
  97   return (f);
  98 }
  99
 100 /*----- That's all, folks -------------------------------------------------*/