3 * $Id: field.c,v 1.3 2004/04/01 12:50:09 mdw Exp $
5 * Abstract field operations
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.3 2004/04/01 12:50:09 mdw
34 * Add cyclic group abstraction, with test code. Separate off exponentation
35 * functions for better static linking. Fix a buttload of bugs on the way.
36 * Generally ensure that negative exponents do inversion correctly. Add
37 * table of standard prime-field subgroups. (Binary field subgroups are
38 * currently unimplemented but easy to add if anyone ever finds a good one.)
40 * Revision 1.2 2004/03/21 22:52:06 mdw
41 * Merge and close elliptic curve branch.
43 * Revision 1.1.4.1 2003/06/10 13:43:53 mdw
44 * Simple (non-projective) curves over prime fields now seem to work.
46 * Revision 1.1 2001/05/07 17:30:13 mdw
47 * Add an internal-representation no-op function.
51 /*----- Header files ------------------------------------------------------*/
56 /*----- Main code ---------------------------------------------------------*/
58 /* --- @field_id@ --- *
60 * Arguments: @field *f@ = pointer to a field
61 * @mp *d@ = a destination element
62 * @mp *x@ = a source element
64 * Returns: The result element.
66 * Use: An identity operation which can be used if your field has no
67 * internal representation.
70 mp
*field_id(field
*f
, mp
*d
, mp
*x
)
77 /* --- @field_samep@ --- *
79 * Arguments: @field *f, *g@ = two fields
81 * Returns: Nonzero if the fields are identical (not just isomorphic).
83 * Use: Checks for sameness of fields. This function does the full
84 * check, not just the field-type-specific check done by the
85 * @sampep@ field operation.
88 int field_samep(field
*f
, field
*g
)
90 return (f
->ops
== g
->ops
&& F_SAMEP(f
, g
));
93 /* --- @field_stdsamep@ --- *
95 * Arguments: @field *f, *g@ = two fields
97 * Returns: Nonzero if the fields are identical (not just isomorphic).
99 * Use: Standard sameness check, based on equality of the @m@
103 int field_stdsamep(field
*f
, field
*g
)
105 return (MP_EQ(f
->m
, g
->m
));
108 /*----- That's all, folks -------------------------------------------------*/