Line data Source code
1 : /* mdfilter.c - filter data and calculate a message digest
2 : * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
3 : *
4 : * This file is part of GnuPG.
5 : *
6 : * GnuPG is free software; you can redistribute it and/or modify
7 : * it under the terms of the GNU General Public License as published by
8 : * the Free Software Foundation; either version 3 of the License, or
9 : * (at your option) any later version.
10 : *
11 : * GnuPG is distributed in the hope that it will be useful,
12 : * but 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 this program; if not, see <http://www.gnu.org/licenses/>.
18 : */
19 :
20 : #include <config.h>
21 : #include <stdio.h>
22 : #include <stdlib.h>
23 : #include <string.h>
24 : #include <errno.h>
25 :
26 : #include "gpg.h"
27 : #include "status.h"
28 : #include "iobuf.h"
29 : #include "util.h"
30 : #include "filter.h"
31 :
32 :
33 :
34 : /****************
35 : * This filter is used to collect a message digest
36 : */
37 : int
38 746 : md_filter( void *opaque, int control,
39 : IOBUF a, byte *buf, size_t *ret_len)
40 : {
41 746 : size_t size = *ret_len;
42 746 : md_filter_context_t *mfx = opaque;
43 746 : int i, rc=0;
44 :
45 746 : if( control == IOBUFCTRL_UNDERFLOW ) {
46 480 : if( mfx->maxbuf_size && size > mfx->maxbuf_size )
47 0 : size = mfx->maxbuf_size;
48 480 : i = iobuf_read( a, buf, size );
49 480 : if( i == -1 ) i = 0;
50 480 : if( i ) {
51 347 : gcry_md_write(mfx->md, buf, i );
52 347 : if( mfx->md2 )
53 0 : gcry_md_write(mfx->md2, buf, i );
54 : }
55 : else
56 133 : rc = -1; /* eof */
57 480 : *ret_len = i;
58 : }
59 266 : else if( control == IOBUFCTRL_DESC )
60 0 : mem2str (buf, "md_filter", *ret_len);
61 746 : return rc;
62 : }
63 :
64 :
65 : void
66 2274 : free_md_filter_context( md_filter_context_t *mfx )
67 : {
68 2274 : gcry_md_close(mfx->md);
69 2274 : gcry_md_close(mfx->md2);
70 2274 : mfx->md = NULL;
71 2274 : mfx->md2 = NULL;
72 2274 : mfx->maxbuf_size = 0;
73 2274 : }
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