Support for Optimal Asymmetric Encryption Padding.

[u/mdw/catacomb] / oaep.h

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+/* -*-c-*-
+ *
+ * $Id: oaep.h,v 1.1 2000/07/01 11:18:30 mdw Exp $
+ *
+ * Optimal asymmetric encryption packing
+ *
+ * (c) 2000 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: oaep.h,v $
+ * Revision 1.1  2000/07/01 11:18:30  mdw
+ * Support for Optimal Asymmetric Encryption Padding.
+ *
+ */
+
+/*----- Notes on OAEP -----------------------------------------------------*
+ *
+ * Applying OAEP before RSA encryption renders the construction plaintext-
+ * aware under the random oracle model.  This is probably a good thing.  OAEP
+ * was designed by Bellare and Rogaway.  This particular variant is the one
+ * specified in PKCS#1 version 2.0.  It's apparently not compatible with the
+ * OAEP used in the SET protocols.
+ */
+
+#ifndef CATACOMB_OAEP_H
+#define CATACOMB_OAEP_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+
+#ifndef CATACOMB_GCIPHER_H
+#  include "gcipher.h"
+#endif
+
+#ifndef CATACOMB_GHASH_H
+#  include "ghash.h"
+#endif
+
+#ifndef CATACOMB_GRAND_H
+#  include "grand.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct oaep {
+  const gccipher *cc;                  /* Cipher class for masking */
+  const gchash *ch;                    /* Hash class for parameter block */
+  grand *r;                            /* Random number source */
+  const void *ep;                      /* Encoding parameters block */
+  size_t epsz;                         /* Size of the parameter block */
+} oaep;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @oaep_encode@ --- *
+ *
+ * Arguments:  @const void *msg@ = pointer to message data
+ *             @size_t msz@ = size of message data
+ *             @void *buf@ = pointer to output buffer
+ *             @size_t sz@ = size of the output buffer
+ *             @void *p@ = pointer to OAEP parameter block
+ *
+ * Returns:    Zero if all went well, negative on failure.
+ *
+ * Use:                Implements the operation @EME-OAEP-ENCODE@, as defined in
+ *             PKCS#1 v. 2.0 (RFC2437).
+ */
+
+extern int oaep_encode(const void */*msg*/, size_t /*msz*/,
+                      void */*buf*/, size_t /*sz*/, void */*p*/);
+
+/* --- @oaep_decode@ --- *
+ *
+ * Arguments:  @const void *buf@ = pointer to encoded buffer
+ *             @size_t sz@ = size of the encoded buffer
+ *             @dstr *d@ = pointer to destination string
+ *             @void *p@ = pointer to OAEP parameter block
+ *
+ * Returns:    The length of the output string if successful, negative on
+ *             failure.
+ *
+ * Use:                Implements the operation @EME-OAEP-DECODE@, as defined in
+ *             PKCS#1 v. 2.0 (RFC2437).
+ */
+
+extern int oaep_decode(const void */*buf*/, size_t /*sz*/,
+                      dstr */*d*/, void */*p*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif