nix/libutil/gcrypt-hash.hh

   1 /* GNU Guix --- Functional package management for GNU
   2    Copyright (C) 2012, 2013  Ludovic Courtès <ludo@gnu.org>
   3
   4    This file is part of GNU Guix.
   5
   6    GNU Guix is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or (at
   9    your option) any later version.
  10
  11    GNU Guix is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 /* An OpenSSL-like interface to GNU libgcrypt cryptographic hash
  20    functions.  */
  21
  22 #pragma once
  23 #include <gcrypt.h>
  24 #include <unistd.h>
  25
  26 struct guix_hash_context
  27 {
  28   /* This copy constructor is needed in 'HashSink::currentHash()' where we
  29      expect the copy of a 'Ctx' object to yield a truly different context.  */
  30   guix_hash_context (guix_hash_context &ref)
  31   {
  32     if (ref.md_handle == NULL)
  33       md_handle = NULL;
  34     else
  35       gcry_md_copy (&md_handle, ref.md_handle);
  36   }
  37
  38   /* Make sure 'md_handle' is always initialized.  */
  39   guix_hash_context (): md_handle (NULL) { };
  40
  41   gcry_md_hd_t md_handle;
  42 };
  43
  44 extern "C" {
  45 extern void guix_hash_init (struct guix_hash_context *ctx, int algo);
  46 extern void guix_hash_update (struct guix_hash_context *ctx, const void *buffer,
  47                               size_t len);
  48 extern void guix_hash_final (void *resbuf, struct guix_hash_context *ctx,
  49                              int algo);
  50 }