X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/bc985cefafea2e1b02095a2ff2a9982c4c647d17..1ba83484ee5bb486da9aa958576de4bc29ef0c1d:/field.h

diff --git a/field.h b/field.h
index db27e63..7af9b4f 100644
--- a/field.h
+++ b/field.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: field.h,v 1.6 2004/03/23 15:19:32 mdw Exp $
+ * $Id: field.h,v 1.8 2004/03/27 17:54:11 mdw Exp $
  *
  * Definitions for field arithmetic
  *
@@ -30,6 +30,12 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: field.h,v $
+ * Revision 1.8  2004/03/27 17:54:11  mdw
+ * Standard curves and curve checking.
+ *
+ * Revision 1.7  2004/03/27 00:04:46  mdw
+ * Implement efficient reduction for pleasant-looking primes.
+ *
  * Revision 1.6  2004/03/23 15:19:32  mdw
  * Test elliptic curves more thoroughly.
  *
@@ -73,11 +79,18 @@
 #  include "mp.h"
 #endif
 
+#ifndef CATACOMB_QDPARSE_H
+#  include "qdparse.h"
+#endif
+
 /*----- Data structures ---------------------------------------------------*/
 
 typedef struct field {
   const struct field_ops *ops;		/* Field operations */
   mp *zero, *one;			/* Identities in the field */
+  mp *m;				/* Modulus (prime and binary) */
+  unsigned long nbits;			/* Length of field element in bits */
+  size_t noctets;			/* Length of element in octets */
 } field;
 
 enum {
@@ -179,6 +192,18 @@ extern mp *field_id(field */*f*/, mp */*d*/, mp */*x*/);
 
 extern field *field_prime(mp */*p*/);
 
+/* --- @field_niceprime@ --- *
+ *
+ * Arguments:	@mp *p@ = the characteristic of the field
+ *
+ * Returns:	A pointer to the field.
+ *
+ * Use:		Creates a field structure for a prime field of size %$p$%,
+ *		using efficient reduction for nice primes.
+ */
+
+extern field *field_niceprime(mp */*p*/);
+
 /* --- @field_binpoly@ --- *
  *
  * Arguments:	@mp *p@ = an irreducible polynomial over %$\gf{2}$%
@@ -191,6 +216,21 @@ extern field *field_prime(mp */*p*/);
 
 extern field *field_binpoly(mp */*p*/);
 
+/* --- @field_parse@ --- *
+ *
+ * Arguments:	@qd_parse *qd@ = parser context
+ *
+ * Returns:	Field pointer if OK, or null.
+ *
+ * Use:		Parses a field description, which has the form
+ *
+ *		  * `prime', `niceprime' or `binpoly'
+ *		  * an optional `:'
+ *		  * the field modulus
+ */
+
+extern field *field_parse(qd_parse */*qd*/);
+
 /*----- That's all, folks -------------------------------------------------*/
 
 #ifdef __cplusplus