X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/math/strongprime.h

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+/* -*-c-*-
+ *
+ * Generate `strong' prime numbers
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#ifndef CATACOMB_STRONGPRIME_H
+#define CATACOMB_STRONGPRIME_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#ifndef CATACOMB_GRAND_H
+#  include "grand.h"
+#endif
+
+#ifndef CATACOMB_PGEN_H
+#  include "pgen.h"
+#endif
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @strongprime_setup@ --- *
+ *
+ * Arguments:	@const char *name@ = pointer to name root
+ *		@mp *d@ = destination for search start point
+ *		@pfilt *f@ = where to store filter jump context
+ *		@unsigned nbits@ = number of bits wanted
+ *		@grand *r@ = random number source
+ *		@unsigned n@ = number of attempts to make
+ *		@pgen_proc *event@ = event handler function
+ *		@void *ectx@ = argument for the event handler
+ *
+ * Returns:	A starting point for a `strong' prime search, or zero.
+ *
+ * Use:		Sets up for a strong prime search, so that primes with
+ *		particular properties can be found.  It's probably important
+ *		to note that the number left in the filter context @f@ is
+ *		congruent to 2 (mod 4).
+ */
+
+extern mp *strongprime_setup(const char */*name*/, mp */*d*/, pfilt */*f*/,
+			     unsigned /*nbits*/, grand */*r*/,
+			     unsigned /*n*/, pgen_proc */*event*/,
+			     void */*ectx*/);
+
+/* --- @strongprime@ --- *
+ *
+ * Arguments:	@const char *name@ = pointer to name root
+ *		@mp *d@ = destination integer
+ *		@unsigned nbits@ = number of bits wanted
+ *		@grand *r@ = random number source
+ *		@unsigned n@ = number of attempts to make
+ *		@pgen_proc *event@ = event handler function
+ *		@void *ectx@ = argument for the event handler
+ *
+ * Returns:	A `strong' prime, or zero.
+ *
+ * Use:		Finds `strong' primes.  A strong prime %$p$% is such that
+ *
+ *		  * %$p - 1$% has a large prime factor %$r$%,
+ *		  * %$p + 1$% has a large prime factor %$s$%, and
+ *		  * %$r - 1$% has a large prime factor %$t$%.
+ *
+ *		The numbers produced may be slightly larger than requested,
+ *		by a few bits.
+ */
+
+extern mp *strongprime(const char */*name*/, mp */*d*/, unsigned /*nbits*/,
+		       grand */*r*/, unsigned /*n*/,
+		       pgen_proc */*event*/, void */*ectx*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif