/* verify.c - verify signed data
* Copyright (C) 1998, 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <unistd.h> /* for isatty() */
#include "options.h"
#include "packet.h"
#include "errors.h"
#include "iobuf.h"
#include "keydb.h"
#include "memory.h"
#include "util.h"
#include "main.h"
#include "status.h"
#include "filter.h"
#include "ttyio.h"
#include "i18n.h"
/****************
* Assume that the input is a signature and verify it without
* generating any output. With no arguments, the signature packet
* is read from stdin (it may be a detached signature when not
* used in batch mode). If only a sigfile is given, it may be a complete
* signature or a detached signature in which case the signed stuff
* is expected from stdin. With more than 1 argument, the first should
* be a detached signature and the remaining files are the signed stuff.
*/
int
verify_signatures( int nfiles, char **files )
{
IOBUF fp;
armor_filter_context_t afx;
progress_filter_context_t pfx;
const char *sigfile;
int i, rc;
STRLIST sl;
memset( &afx, 0, sizeof afx);
/* decide whether we should handle a detached or a normal signature,
* which is needed so that the code later can hash the correct data and
* not have a normal signature act as detached signature and ignoring the
* indended signed material from the 2nd file or stdin.
* 1. gpg <file - normal
* 2. gpg file - normal (or detached)
* 3. gpg file <file2 - detached
* 4. gpg file file2 - detached
* The question is how decide between case 2 and 3? The only way
* we can do it is by reading one byte from stdin and the unget
* it; the problem here is that we may be reading from the
* terminal (which could be detected using isatty() but won't work
* when under contol of a pty using program (e.g. expect)) and
* might get us in trouble when stdin is used for another purpose
* (--passphrase-fd 0). So we have to break with the behaviour
* prior to gpg 1.0.4 by assuming that case 3 is a normal
* signature (where file2 is ignored and require for a detached
* signature to indicate signed material comes from stdin by using
* case 4 with a file2 of "-".
*
* Actually we don't have to change anything here but can handle
* that all quite easily in mainproc.c
*/
sigfile = nfiles? *files : NULL;
/* open the signature file */
fp = iobuf_open(sigfile);
if (fp && is_secured_file (iobuf_get_fd (fp)))
{
iobuf_close (fp);
fp = NULL;
errno = EPERM;
}
if( !fp ) {
log_error(_("can't open `%s'\n"), print_fname_stdin(sigfile));
return G10ERR_OPEN_FILE;
}
handle_progress (&pfx, fp, sigfile);
if( !opt.no_armor && use_armor_filter( fp ) )
iobuf_push_filter( fp, armor_filter, &afx );
sl = NULL;
for(i=nfiles-1 ; i > 0 ; i-- )
add_to_strlist( &sl, files[i] );
rc = proc_signature_packets( NULL, fp, sl, sigfile );
free_strlist(sl);
iobuf_close(fp);
if( (afx.no_openpgp_data && rc == -1) || rc == G10ERR_NO_DATA ) {
log_error(_("the signature could not be verified.\n"
"Please remember that the signature file (.sig or .asc)\n"
"should be the first file given on the command line.\n") );
rc = 0;
}
return rc;
}
void
print_file_status( int status, const char *name, int what )
{
char *p = xmalloc(strlen(name)+10);
sprintf(p, "%d %s", what, name );
write_status_text( status, p );
xfree(p);
}
static int
verify_one_file( const char *name )
{
IOBUF fp;
armor_filter_context_t afx;
progress_filter_context_t pfx;
int rc;
print_file_status( STATUS_FILE_START, name, 1 );
fp = iobuf_open(name);
if (fp)
iobuf_ioctl (fp,3,1,NULL); /* disable fd caching */
if (fp && is_secured_file (iobuf_get_fd (fp)))
{
iobuf_close (fp);
fp = NULL;
errno = EPERM;
}
if( !fp ) {
print_file_status( STATUS_FILE_ERROR, name, 1 );
log_error(_("can't open `%s'\n"), print_fname_stdin(name));
return G10ERR_OPEN_FILE;
}
handle_progress (&pfx, fp, name);
if( !opt.no_armor ) {
if( use_armor_filter( fp ) ) {
memset( &afx, 0, sizeof afx);
iobuf_push_filter( fp, armor_filter, &afx );
}
}
rc = proc_signature_packets( NULL, fp, NULL, name );
iobuf_close(fp);
write_status( STATUS_FILE_DONE );
return rc;
}
/****************
* Verify each file given in the files array or read the names of the
* files from stdin.
* Note: This function can not handle detached signatures.
*/
int
verify_files( int nfiles, char **files )
{
int i;
if( !nfiles ) { /* read the filenames from stdin */
char line[2048];
unsigned int lno = 0;
while( fgets(line, DIM(line), stdin) ) {
lno++;
if( !*line || line[strlen(line)-1] != '\n' ) {
log_error(_("input line %u too long or missing LF\n"), lno );
return G10ERR_GENERAL;
}
/* This code does not work on MSDOS but how cares there are
* also no script languages available. We don't strip any
* spaces, so that we can process nearly all filenames */
line[strlen(line)-1] = 0;
verify_one_file( line );
iobuf_ioctl( NULL, 2, 0, NULL); /* Invalidate entire cache. */
}
}
else { /* take filenames from the array */
for(i=0; i < nfiles; i++ ) {
verify_one_file( files[i] );
iobuf_ioctl( NULL, 2, 0, NULL); /* Invalidate entire cache. */
}
}
return 0;
}