Gather up another utility.

[u/mdw/catacomb] / bbs-rand.c

diff --git a/bbs-rand.c b/bbs-rand.c
index 054a158..3d2563a 100644 (file)
--- a/bbs-rand.c
+++ b/bbs-rand.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: bbs-rand.c,v 1.1 1999/12/10 23:14:59 mdw Exp $
+ * $Id: bbs-rand.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
  *
  * Blum-Blum-Shub secure random number generator
  *
@@ -27,14 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: bbs-rand.c,v $
- * Revision 1.1  1999/12/10 23:14:59  mdw
- * Blum-Blum-Shub generator, and Blum-Goldwasser encryption.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include <stdarg.h>
@@ -44,11 +36,14 @@
 #include <mLib/bits.h>
 #include <mLib/sub.h>
 
+#include "arena.h"
 #include "bbs.h"
 #include "grand.h"
 #include "mp.h"
 #include "mpbarrett.h"
 #include "mpint.h"
+#include "mprand.h"
+#include "paranoia.h"
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -124,8 +119,7 @@ void bbs_step(bbs *b)
 
 void bbs_set(bbs *b, mp *x)
 {
-  if (b->x)
-    mp_drop(b->x);
+  mp_drop(b->x);
   b->x = MP_COPY(x);
   bbs_step(b);
 }
@@ -208,7 +202,7 @@ 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.
  */
 
 void bbs_wrap(bbs *b)
@@ -228,7 +222,8 @@ static void gdestroy(grand *r)
 {
   gctx *g = (gctx *)r;
   bbs_destroy(&g->b);
-  DESTROY(g);
+  BURN(*g);
+  S_DESTROY(g);
 }
 
 static int gmisc(grand *r, unsigned op, ...)
@@ -245,6 +240,7 @@ static int gmisc(grand *r, unsigned op, ...)
         case GRAND_SEEDINT:
         case GRAND_SEEDUINT32:
         case GRAND_SEEDMP:
+       case GRAND_SEEDRAND:
        case BBS_SET:
           rc = 1;
           break;
@@ -266,6 +262,12 @@ static int gmisc(grand *r, unsigned op, ...)
     case GRAND_SEEDMP:
       bbs_seed(&g->b, va_arg(ap, mp *));
       break;
+    case GRAND_SEEDRAND: {
+      grand *rr = va_arg(ap, grand *);
+      mp *m = mprand(MP_NEW, mp_bits(g->b.mb.m) - 1, rr, 0);
+      bbs_seed(&g->b, m);
+      mp_drop(m);
+    } break;
     case BBS_SET:
       bbs_set(&g->b, va_arg(ap, mp *));
       break;
@@ -292,7 +294,7 @@ static uint32 gword(grand *r)
 
 static const grand_ops gops = {
   "bbs",
-  0,
+  GRAND_CRYPTO, 0,
   gmisc, gdestroy,
   gword, gbyte, gword, grand_range, grand_fill
 };
@@ -310,7 +312,7 @@ static const grand_ops gops = {
 
 grand *bbs_rand(mp *m, mp *x)
 {
-  gctx *g = CREATE(gctx);
+  gctx *g = S_CREATE(gctx);
   g->r.ops = &gops;
   bbs_create(&g->b, m, x);
   return (&g->r);