X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/b817bfc642225b8c3c0b6a7e42d1fb949b61a606..1d7857e79cfb9d5b41fe13935b0a0bf68f6049f5:/field.h

diff --git a/field.h b/field.h
index 5790284..4164bce 100644
--- a/field.h
+++ b/field.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: field.h,v 1.11 2004/04/08 01:36:15 mdw Exp $
+ * $Id$
  *
  * Definitions for field arithmetic
  *
@@ -56,6 +56,7 @@ typedef struct field {
   mp *m;				/* Modulus (prime and binary) */
   unsigned long nbits;			/* Length of field element in bits */
   size_t noctets;			/* Length of element in octets */
+  mp *q;				/* Number of elements in field */
 } field;
 
 enum {
@@ -170,6 +171,25 @@ extern int field_samep(field */*f*/, field */*g*/);
 
 extern int field_stdsamep(field */*f*/, field */*g*/);
 
+/*----- Arithmetic --------------------------------------------------------*/
+
+/* --- @field_exp@ --- *
+ *
+ * Arguments:	@field *f@ = pointer to field
+ *		@mp *d@ = fake destination
+ *		@mp *a@ = base
+ *		@mp *e@ = exponent
+ *
+ * Returns:	Result, %$a^e$%.
+ *
+ * Use:		Exponentiation in a finite field.  Note that all quantities
+ *		are in internal format.  This is a generic implementation
+ *		suitable for use with all fields and is not intended to be
+ *		optimal.
+ */
+
+extern mp *field_exp(field */*f*/, mp */*d*/, mp */*a*/, mp */*e*/);
+
 /*----- Creating fields ---------------------------------------------------*/
 
 /* --- @field_prime@ --- *