X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ea303d6c25ad89731319b1e704888d06f85a94b1..4e66da02f19648ee1be862e67ba1d1fc5549fb7f:/gfshare.c

diff --git a/gfshare.c b/gfshare.c
index 7854f7d..841e556 100644
--- a/gfshare.c
+++ b/gfshare.c
@@ -1,8 +1,8 @@
 /* -*-c-*-
  *
- * $Id: gfshare.c,v 1.5 2000/06/24 19:11:47 mdw Exp $
+ * $Id: gfshare.c,v 1.8 2004/04/02 01:03:49 mdw Exp $
  *
- * Secret sharing over %$\gf(2^8)$%
+ * Secret sharing over %$\gf{2^8}$%
  *
  * (c) 2000 Straylight/Edgeware
  */
@@ -30,6 +30,16 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: gfshare.c,v $
+ * Revision 1.8  2004/04/02 01:03:49  mdw
+ * Miscellaneous constification.
+ *
+ * Revision 1.7  2001/06/16 23:42:17  mdw
+ * Typesetting fixes.
+ *
+ * Revision 1.6  2000/12/06 20:30:10  mdw
+ * Change secret sharing interface: present the secret at share
+ * construction time.
+ *
  * Revision 1.5  2000/06/24 19:11:47  mdw
  * Fix daft error in the comment for @gfshare_get@.
  *
@@ -66,7 +76,7 @@
 
 /*----- Static variables --------------------------------------------------*/
 
-static octet gflog[] = GFSHARE_LOG, gfexp[] = GFSHARE_EXP;
+static const octet gflog[] = GFSHARE_LOG, gfexp[] = GFSHARE_EXP;
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -86,7 +96,6 @@ void gfshare_create(gfshare *s, unsigned t, size_t sz)
   s->t = t;
   s->i = 0;
   s->sz = sz;
-  s->s = 0;
   s->v = 0;
 }
 
@@ -111,22 +120,23 @@ void gfshare_destroy(gfshare *s)
  *
  * Arguments:	@gfshare *s@ = pointer to share context to fill in
  *		@grand *r@ = pointer to random number source
+ *		@const void *buf@ = pointer to the secret to share
  *
  * Returns:	---
  *
  * Use:		Initializes a sharing context to be able to create shares.
  *		The context structure is expected to be mostly filled in.  In
- *		particular, @t@ and @s@ must be initialized.  If @v@ is zero,
- *		a vector of appropriate size is allocated.  You should use
- *		the macro @GFSHARE_INIT@ or @gfshare_create@ to construct
- *		sharing contexts.
+ *		particular, @t@ must be initialized.  If @v@ is zero, a
+ *		vector of appropriate size is allocated.  You should use the
+ *		macro @GFSHARE_INIT@ or @gfshare_create@ to construct sharing
+ *		contexts.
  */
 
-void gfshare_mkshares(gfshare *s, grand *r)
+void gfshare_mkshares(gfshare *s, grand *r, const void *buf)
 {
   s->v = XS_ALLOC(s->sz * s->t);
   r->ops->fill(r, s->v, s->sz * (s->t - 1));
-  memcpy(s->v + s->sz * (s->t - 1), s->s, s->sz);
+  memcpy(s->v + s->sz * (s->t - 1), buf, s->sz);
 }
 
 /* --- @gfshare_get@ --- *
@@ -290,9 +300,8 @@ static int verify(grand *r)
   r->ops->fill(r, sec, len);
 
   gfshare_create(&s, t, len);
-  s.s = sec;
 
-  gfshare_mkshares(&s, r);
+  gfshare_mkshares(&s, r, sec);
   for (i = 0; i < t; i++)
     gfshare_get(&s, p[i], v + (i * len));
   gfshare_destroy(&s);