Merge branch 'master' of git+ssh://metalzone.distorted.org.uk/~mdw/public-git/catacomb/

[u/mdw/catacomb] / rabin.c

diff --git a/rabin.c b/rabin.c
index 200ab0d..4c08f87 100644 (file)
--- a/rabin.c
+++ b/rabin.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rabin.c,v 1.8 2004/04/02 01:03:49 mdw Exp $
+ * $Id$
  *
  * Miller-Rabin primality test
  *
@@ -27,37 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: rabin.c,v $
- * Revision 1.8  2004/04/02 01:03:49  mdw
- * Miscellaneous constification.
- *
- * Revision 1.7  2002/01/13 13:42:53  mdw
- * More efficient Rabin-Miller test: with random witnesses, skip redundant
- * Montgomerization.  (Being bijective, it can't affect the distribution.)
- *
- * Revision 1.6  2001/06/16 12:56:38  mdw
- * Fixes for interface change to @mpmont_expr@ and @mpmont_mexpr@.
- *
- * Revision 1.5  2000/10/08 12:11:22  mdw
- * Use @MP_EQ@ instead of @MP_CMP@.
- *
- * Revision 1.4  2000/06/22 19:03:02  mdw
- * Use the new @mp_odd@ function.
- *
- * Revision 1.3  1999/12/22 15:50:29  mdw
- * Reworking for new prime-search system.  Add function for working out how
- * many iterations to use for a particular number.
- *
- * Revision 1.2  1999/12/10 23:29:48  mdw
- * Change header file guard names.
- *
- * Revision 1.1  1999/11/19 13:17:57  mdw
- * Prime number generator and tester.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include "mp.h"
@@ -73,19 +42,23 @@
  * Arguments:  @rabin *r@ = pointer to Rabin-Miller context
  *             @mp *m@ = pointer to number to test
  *
- * Returns:    ---
+ * Returns:    Zero on success, nonzero on failure.
  *
  * Use:                Precomputes some useful values for performing the
  *             Miller-Rabin probabilistic primality test.
  */
 
-void rabin_create(rabin *r, mp *m)
+int rabin_create(rabin *r, mp *m)
 {
   mp *m1 = mp_sub(MP_NEW, m, MP_ONE);
-  mpmont_create(&r->mm, m);
+  if (mpmont_create(&r->mm, m)) {
+    MP_DROP(m1);
+    return (-1);
+  }
   r->r = mp_odd(MP_NEW, m1, &r->s);
   r->m1 = mp_sub(MP_NEW, m, r->mm.r);
   mp_drop(m1);
+  return (0);
 }
 
 /* --- @rabin_destroy@ --- *