X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/59919ae4b1721ca271c3d3e5955c09d322573821..e9026a0a6d8fc5cbcfa8d658176bfd2776cb550e:/gkcdsa.h

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+/* -*-c-*-
+ *
+ * $Id: gkcdsa.h,v 1.1 2004/04/04 19:42:59 mdw Exp $
+ *
+ * Generalized version of KCDSA
+ *
+ * (c) 2004 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.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: gkcdsa.h,v $
+ * Revision 1.1  2004/04/04 19:42:59  mdw
+ * Add set -e.
+ *
+ */
+
+#ifndef CATACOMB_GKCDSA_H
+#define CATACOMB_GKCDSA_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#ifndef CATACOMB_GROUP_H
+#  include "group.h"
+#endif
+
+#ifndef CATACOMB_GHASH_H
+#  include "ghash.h"
+#endif
+
+#ifndef CATACOMB_GDSA_H
+#  include "gdsa.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+/* --- Careful! --- *
+ *
+ * These structures are the same as for DSA.  However, the private key @u@ is
+ * the %$\emph{inverse}$% of the exponent.  Do this wrong and the maths will
+ * fail hopelessly.
+ */
+
+typedef gdsa gkcdsa;
+
+typedef struct gkcdsa_sig {
+  octet *r;				/* Null means @xmalloc@ me */
+  mp *s;
+} gkcdsa_sig;
+#define GKCDSA_SIG_INIT { 0, 0 }
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @gdsa_beginhash@ --- *
+ *
+ * Arguments:	@const gdsa *c@ = pointer to the context structure
+ *
+ * Returns:	A hashing context for you to hash the message.
+ *
+ * Use:		Initializes a hash function correctly for you to hash a
+ *		message.  Requires @h@, @g@ and @p@.
+ */
+
+extern ghash *gkcdsa_beginhash(const gkcdsa */*c*/);
+
+/* --- @gkcdsa_endhash@ --- *
+ *
+ * Arguments:	@const gkcdsa *c@ = pointer to the context structure
+ *		@ghash *h@ = the hashing context
+ *
+ * Returns:	---
+ *
+ * Use:		Does any final thing that KCDSA wants to do when hashing a
+ *		message.  (Actually, there's nothing.)  The hashing context
+ *		isn't finalized.
+ */
+
+extern void gkcdsa_endhash(gkcdsa */*c*/, ghash */*h*/);
+
+/* --- @gkcdsa_sign@ --- *
+ *
+ * Arguments:	@const gkcdsa *c@ = my context structure
+ *		@gkcdsa_sig *s@ = where to put the signature (initialized)
+ *		@const void *m@ = pointer to message hash
+ *		@mp *k@ = random exponent for this message or null
+ *
+ * Returns:	---
+ *
+ * Use:		Signs a message.  Requires @g@, @u@, @h@, and @r@ if @k@ is
+ *		null.  This is a better idea than inventing @k@ yourself.
+ */
+
+extern void gkcdsa_sign(const gkcdsa */*c*/, gkcdsa_sig */*s*/,
+			const void */*m*/, mp */*k*/);
+
+/* --- @gkcdsa_verify@ --- *
+ *
+ * Arguments:	@const gkcdsa *c@ = my context structure
+ *		@const gkcdsa_sig *s@ = the signature to verify
+ *		@const void *m@ = pointer to message hash
+ *
+ * Returns:	Zero if OK, negative on failure.
+ *
+ * Use:		Checks a signature on a message,  Requires @g@, @p@, @h@.
+ */
+
+extern int gkcdsa_verify(const gkcdsa */*c*/, const gkcdsa_sig */*s*/,
+			 const void */*m*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif