X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/4f743df55ac05e51bc69aaabd188132f2f94543b..d34decd2b2b88240cf4ca68a2a5feb7bf36de6e7:/bbs.h

diff --git a/bbs.h b/bbs.h
index 485fb76..2098745 100644
--- a/bbs.h
+++ b/bbs.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: bbs.h,v 1.2 1999/12/22 15:52:08 mdw Exp $
+ * $Id: bbs.h,v 1.4 2000/06/17 10:45:48 mdw Exp $
  *
  * The Blum-Blum-Shub random bit generator
  *
@@ -30,6 +30,12 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: bbs.h,v $
+ * Revision 1.4  2000/06/17 10:45:48  mdw
+ * Minor changes for key fetching.  Typesetting fixes.
+ *
+ * Revision 1.3  2000/02/12 18:21:02  mdw
+ * Overhaul of key management (again).
+ *
  * Revision 1.2  1999/12/22 15:52:08  mdw
  * Rename `bbs_params' to `bbs_param' for consistency.
  *
@@ -44,14 +50,14 @@
  * sequence %$x_i = x_{i - 1}^2 \bmod n$%, where %$n = pq$% is the product of
  * two primes %$p$% and %$q$%, each of which are congruent to %$3 \bmod 4$%.
  * For maximum period of the generator, %$(p - 1)/2$% and %$(q - 1)/1$%
- * should be coprime.  It is safe to use the least significant %$\log \log
- * n$% bits of each step in the sequence -- an adversary must factor the
- * modulus before being able to work forwards or backwards.  The output of
- * the generator cannot be distinguished from a (uniform, independent) random
- * sequence of bits using any polynomial-time test.  This is by far the
- * strongest pseudorandom number generator provided in Catacomb, and by far
- * the slowest too.  For normal use, the standard Catacomb @rand@ generator
- * should be more than adequate.
+ * should be coprime.  It is safe to use the least significant
+ * %$\log \log n$% bits of each step in the sequence -- an adversary must
+ * factor the modulus before being able to work forwards or backwards.  The
+ * output of the generator cannot be distinguished from a (uniform,
+ * independent) random sequence of bits using any polynomial-time test.  This
+ * is by far the strongest pseudorandom number generator provided in
+ * Catacomb, and by far the slowest too.  For normal use, the standard
+ * Catacomb @rand@ generator should be more than adequate.
  */
 
 #ifndef CATACOMB_BBS_H
@@ -69,6 +75,10 @@
 #  include "grand.h"
 #endif
 
+#ifndef CATACOMB_KEY_H
+#  include "key.h"
+#endif
+
 #ifndef CATACOMB_MP_H
 #  include "mp.h"
 #endif
@@ -95,10 +105,22 @@ typedef struct bbs {
 
 /* --- Parameters --- */
 
+typedef struct bbs_pub {
+  mp *n;
+} bbs_pub;
+
 typedef struct bbs_param {
   mp *p, *q;				/* Prime factors (3 mod 4) */
   mp *n;				/* Product @pq@ -- a Blum integer */
-} bbs_param;
+} bbs_param, bbs_priv;
+
+/*----- Key fetching ------------------------------------------------------*/
+
+extern const key_fetchdef bbs_pubfetch[];
+#define BBS_PUBFETCHSZ 3
+
+extern const key_fetchdef bbs_privfetch[];
+#define BBS_PRIVFETCHSZ 7
 
 /*----- The basic generator -----------------------------------------------*/
 
@@ -189,7 +211,7 @@ extern uint32 bbs_bits(bbs */*b*/, unsigned /*bits*/);
  *
  *		If a generator is seeded, %$b$% bits are extracted, and then
  *		@bbs_wrap@ is called, the generator will have been stepped
- *		%$\lceil b/k \rceil% times.
+ *		%$\lceil b/k \rceil$% times.
  */
 
 extern void bbs_wrap(bbs */*b*/);
@@ -231,8 +253,9 @@ extern void bbs_rew(bbs */*b*/, bbs_param */*bp*/, unsigned long /*n*/);
 /* --- @bbs_gen@ --- *
  *
  * Arguments:	@bbs_param *bp@ = pointer to parameter block
- *		@mp *p, *q@ = initial numbers to search from
- *		@size_t n@ = number of attempts to make
+ *		@unsigned nbits@ = number of bits in the modulus
+ *		@grand *r@ = pointer to random number source
+ *		@unsigned n@ = number of attempts to make
  *		@pgen_proc *event@ = event handler function
  *		@void *ectx@ = argument for event handler
  *
@@ -245,8 +268,8 @@ extern void bbs_rew(bbs */*b*/, bbs_param */*bp*/, unsigned long /*n*/);
  *		Shub pseudorandom bit generator.
  */
 
-extern int bbs_gen(bbs_param */*bp*/, mp */*p*/, mp */*q*/, size_t /*n*/,
-		   pgen_proc */*event*/, void */*ectx*/);
+extern int bbs_gen(bbs_param */*bp*/, unsigned /*nbits*/, grand */*r*/,
+		   unsigned /*n*/, pgen_proc */*event*/, void */*ectx*/);
 
 /*----- Generic random number generator interface -------------------------*/