lib/opencdk/hash.c

   1 /* hash.c - Hash filters
   2  * Copyright (C) 2002-2012 Free Software Foundation, Inc.
   3  *
   4  * Author: Timo Schulz
   5  *
   6  * This file is part of OpenCDK.
   7  *
   8  * The OpenCDK library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  20  *
  21  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26 #include <stdio.h>
  27 #include <sys/stat.h>
  28
  29 #include "opencdk.h"
  30 #include "main.h"
  31 #include "filters.h"
  32
  33 static cdk_error_t
  34 hash_encode (void *data, FILE * in, FILE * out)
  35 {
  36   md_filter_t *mfx = data;
  37   byte buf[BUFSIZE];
  38   int err;
  39   int nread;
  40
  41   if (!mfx)
  42     {
  43       gnutls_assert ();
  44       return CDK_Inv_Value;
  45     }
  46
  47   _cdk_log_debug ("hash filter: encode algo=%d\n", mfx->digest_algo);
  48
  49   if (!mfx->md_initialized)
  50     {
  51       err = _gnutls_hash_init (&mfx->md, mfx->digest_algo);
  52       if (err < 0)
  53         {
  54           gnutls_assert ();
  55           return map_gnutls_error (err);
  56         }
  57
  58       mfx->md_initialized = 1;
  59     }
  60
  61   while (!feof (in))
  62     {
  63       nread = fread (buf, 1, BUFSIZE, in);
  64       if (!nread)
  65         break;
  66       _gnutls_hash (&mfx->md, buf, nread);
  67     }
  68
  69   memset (buf, 0, sizeof (buf));
  70   return 0;
  71 }
  72
  73 cdk_error_t
  74 _cdk_filter_hash (void *data, int ctl, FILE * in, FILE * out)
  75 {
  76   if (ctl == STREAMCTL_READ)
  77     return hash_encode (data, in, out);
  78   else if (ctl == STREAMCTL_FREE)
  79     {
  80       md_filter_t *mfx = data;
  81       if (mfx)
  82         {
  83           _cdk_log_debug ("free hash filter\n");
  84           _gnutls_hash_deinit (&mfx->md, NULL);
  85           mfx->md_initialized = 0;
  86           return 0;
  87         }
  88     }
  89
  90   gnutls_assert ();
  91   return CDK_Inv_Mode;
  92 }