mdw@git.distorted.org.uk Git - catacomb/blob - symm/latinpoly.h

   1 /* -*-c-*-
   2  *
   3  * AEAD schemes based on Salsa20/ChaCha and Poly1305
   4  *
   5  * (c) 2018 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software: you can redistribute it and/or modify it
  13  * under the terms of the GNU Library General Public License as published
  14  * by the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 /*----- Notes on this construction ----------------------------------------*
  29  *
  30  * The AEAD class @chacha20_poly1305@ with a 96-bit nonce is exactly the
  31  * scheme specified in RFC7539.  This implementation extends that
  32  * specification in two ways:
  33  *
  34  *   * It permits ciphers other than ChaCha20: specifically ChaCha%$r$% and
  35  *     Salsa20/%$r$% with %$r \in \{ 8, 12, 20 \}$%.
  36  *
  37  *   * It allows nonces of 64, 96, and 192 bits.  A 64-bit nonce matches
  38  *     Bernstein's original specification of Salsa20 and ChaCha; the 96-bit
  39  *     nonce matches RFC7539; and the 192-bit nonce matches Bernstein's
  40  *     XSalsa20.  The implementation uses XSalsa20 or XChaCha as appropriate
  41  *     automatically based on the provided nonce length.
  42  *
  43  * These extensions do not significantly affect Procter's security analysis
  44  * except that an application should not mix nonce sizes with the same key.
  45  * (It is possible to do this safely, but it requires detailed understanding
  46  * of how everything fits together and isn't worth the effort.)
  47  */
  48
  49 #ifndef CATACOMB_LATINPOLY_H
  50 #define CATACOMB_LATINPOLY_H
  51
  52 #ifdef __cplusplus
  53   extern "C" {
  54 #endif
  55
  56 /*----- Header files ------------------------------------------------------*/
  57
  58 #ifndef CATACOMB_GAEAD_H
  59 #  include "gaead.h"
  60 #endif
  61
  62 /*----- Definitions -------------------------------------------------------*/
  63
  64 extern const gcaead
  65   chacha20_poly1305, chacha12_poly1305, chacha8_poly1305,
  66   salsa20_poly1305, salsa2012_poly1305, salsa208_poly1305;
  67
  68 /*----- That's all, folks -------------------------------------------------*/
  69
  70 #ifdef __cplusplus
  71   }
  72 #endif
  73
  74 #endif