Line data Source code
1 : /* verify.c - Verify signed data
2 : * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006,
3 : * 2007, 2010 Free Software Foundation, Inc.
4 : *
5 : * This file is part of GnuPG.
6 : *
7 : * GnuPG is free software; you can redistribute it and/or modify
8 : * it under the terms of the GNU General Public License as published by
9 : * the Free Software Foundation; either version 3 of the License, or
10 : * (at your option) any later version.
11 : *
12 : * GnuPG is distributed in the hope that it will be useful,
13 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 : * GNU General Public License for more details.
16 : *
17 : * You should have received a copy of the GNU General Public License
18 : * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 : */
20 :
21 : #include <config.h>
22 : #include <stdio.h>
23 : #include <stdlib.h>
24 : #include <string.h>
25 : #include <errno.h>
26 :
27 : #include "gpg.h"
28 : #include "options.h"
29 : #include "packet.h"
30 : #include "status.h"
31 : #include "iobuf.h"
32 : #include "keydb.h"
33 : #include "util.h"
34 : #include "main.h"
35 : #include "status.h"
36 : #include "filter.h"
37 : #include "ttyio.h"
38 : #include "i18n.h"
39 :
40 :
41 : /****************
42 : * Assume that the input is a signature and verify it without
43 : * generating any output. With no arguments, the signature packet
44 : * is read from stdin (it may be a detached signature when not
45 : * used in batch mode). If only a sigfile is given, it may be a complete
46 : * signature or a detached signature in which case the signed stuff
47 : * is expected from stdin. With more than 1 argument, the first should
48 : * be a detached signature and the remaining files are the signed stuff.
49 : */
50 :
51 : int
52 45 : verify_signatures (ctrl_t ctrl, int nfiles, char **files )
53 : {
54 : IOBUF fp;
55 45 : armor_filter_context_t *afx = NULL;
56 45 : progress_filter_context_t *pfx = new_progress_context ();
57 : const char *sigfile;
58 : int i, rc;
59 : strlist_t sl;
60 :
61 : /* Decide whether we should handle a detached or a normal signature,
62 : * which is needed so that the code later can hash the correct data and
63 : * not have a normal signature act as detached signature and ignoring the
64 : * indended signed material from the 2nd file or stdin.
65 : * 1. gpg <file - normal
66 : * 2. gpg file - normal (or detached)
67 : * 3. gpg file <file2 - detached
68 : * 4. gpg file file2 - detached
69 : * The question is how decide between case 2 and 3? The only way
70 : * we can do it is by reading one byte from stdin and then unget
71 : * it; the problem here is that we may be reading from the
72 : * terminal (which could be detected using isatty() but won't work
73 : * when under contol of a pty using program (e.g. expect)) and
74 : * might get us in trouble when stdin is used for another purpose
75 : * (--passphrase-fd 0). So we have to break with the behaviour
76 : * prior to gpg 1.0.4 by assuming that case 3 is a normal
77 : * signature (where file2 is ignored and require for a detached
78 : * signature to indicate signed material comes from stdin by using
79 : * case 4 with a file2 of "-".
80 : *
81 : * Actually we don't have to change anything here but can handle
82 : * that all quite easily in mainproc.c
83 : */
84 :
85 45 : sigfile = nfiles? *files : NULL;
86 :
87 : /* open the signature file */
88 45 : fp = iobuf_open(sigfile);
89 45 : if (fp && is_secured_file (iobuf_get_fd (fp)))
90 : {
91 0 : iobuf_close (fp);
92 0 : fp = NULL;
93 0 : gpg_err_set_errno (EPERM);
94 : }
95 45 : if( !fp ) {
96 0 : rc = gpg_error_from_syserror ();
97 0 : log_error(_("can't open '%s': %s\n"),
98 : print_fname_stdin(sigfile), gpg_strerror (rc));
99 0 : goto leave;
100 : }
101 45 : handle_progress (pfx, fp, sigfile);
102 :
103 45 : if ( !opt.no_armor && use_armor_filter( fp ) )
104 : {
105 23 : afx = new_armor_context ();
106 23 : push_armor_filter (afx, fp);
107 : }
108 :
109 45 : sl = NULL;
110 47 : for(i=nfiles-1 ; i > 0 ; i-- )
111 2 : add_to_strlist( &sl, files[i] );
112 45 : rc = proc_signature_packets (ctrl, NULL, fp, sl, sigfile );
113 42 : free_strlist(sl);
114 42 : iobuf_close(fp);
115 42 : if( (afx && afx->no_openpgp_data && rc == -1)
116 39 : || gpg_err_code (rc) == GPG_ERR_NO_DATA ) {
117 4 : log_error(_("the signature could not be verified.\n"
118 : "Please remember that the signature file (.sig or .asc)\n"
119 : "should be the first file given on the command line.\n") );
120 4 : rc = 0;
121 : }
122 :
123 : leave:
124 42 : release_armor_context (afx);
125 42 : release_progress_context (pfx);
126 42 : return rc;
127 : }
128 :
129 :
130 :
131 : void
132 0 : print_file_status( int status, const char *name, int what )
133 : {
134 0 : char *p = xmalloc(strlen(name)+10);
135 0 : sprintf(p, "%d %s", what, name );
136 0 : write_status_text( status, p );
137 0 : xfree(p);
138 0 : }
139 :
140 :
141 : static int
142 0 : verify_one_file (ctrl_t ctrl, const char *name )
143 : {
144 : IOBUF fp;
145 0 : armor_filter_context_t *afx = NULL;
146 0 : progress_filter_context_t *pfx = new_progress_context ();
147 : int rc;
148 :
149 0 : print_file_status( STATUS_FILE_START, name, 1 );
150 0 : fp = iobuf_open(name);
151 0 : if (fp)
152 0 : iobuf_ioctl (fp, IOBUF_IOCTL_NO_CACHE, 1, NULL);
153 0 : if (fp && is_secured_file (iobuf_get_fd (fp)))
154 : {
155 0 : iobuf_close (fp);
156 0 : fp = NULL;
157 0 : gpg_err_set_errno (EPERM);
158 : }
159 0 : if( !fp ) {
160 0 : rc = gpg_error_from_syserror ();
161 0 : log_error(_("can't open '%s': %s\n"),
162 0 : print_fname_stdin(name), strerror (errno));
163 0 : print_file_status( STATUS_FILE_ERROR, name, 1 );
164 0 : goto leave;
165 : }
166 0 : handle_progress (pfx, fp, name);
167 :
168 0 : if( !opt.no_armor ) {
169 0 : if( use_armor_filter( fp ) ) {
170 0 : afx = new_armor_context ();
171 0 : push_armor_filter (afx, fp);
172 : }
173 : }
174 :
175 0 : rc = proc_signature_packets (ctrl, NULL, fp, NULL, name );
176 0 : iobuf_close(fp);
177 0 : write_status( STATUS_FILE_DONE );
178 :
179 0 : reset_literals_seen();
180 :
181 : leave:
182 0 : release_armor_context (afx);
183 0 : release_progress_context (pfx);
184 0 : return rc;
185 : }
186 :
187 : /****************
188 : * Verify each file given in the files array or read the names of the
189 : * files from stdin.
190 : * Note: This function can not handle detached signatures.
191 : */
192 : int
193 0 : verify_files (ctrl_t ctrl, int nfiles, char **files )
194 : {
195 : int i;
196 :
197 0 : if( !nfiles ) { /* read the filenames from stdin */
198 : char line[2048];
199 0 : unsigned int lno = 0;
200 :
201 0 : while( fgets(line, DIM(line), stdin) ) {
202 0 : lno++;
203 0 : if( !*line || line[strlen(line)-1] != '\n' ) {
204 0 : log_error(_("input line %u too long or missing LF\n"), lno );
205 0 : return GPG_ERR_GENERAL;
206 : }
207 : /* This code does not work on MSDOS but how cares there are
208 : * also no script languages available. We don't strip any
209 : * spaces, so that we can process nearly all filenames */
210 0 : line[strlen(line)-1] = 0;
211 0 : verify_one_file (ctrl, line );
212 : }
213 :
214 : }
215 : else { /* take filenames from the array */
216 0 : for(i=0; i < nfiles; i++ )
217 0 : verify_one_file (ctrl, files[i] );
218 : }
219 0 : return 0;
220 : }
221 :
222 :
223 :
224 :
225 : /* Perform a verify operation. To verify detached signatures, DATA_FD
226 : shall be the descriptor of the signed data; for regular signatures
227 : it needs to be -1. If OUT_FP is not NULL and DATA_FD is not -1 the
228 : the signed material gets written that stream.
229 :
230 : FIXME: OUTFP is not yet implemented.
231 : */
232 : int
233 0 : gpg_verify (ctrl_t ctrl, int sig_fd, int data_fd, estream_t out_fp)
234 : {
235 : int rc;
236 : iobuf_t fp;
237 0 : armor_filter_context_t *afx = NULL;
238 0 : progress_filter_context_t *pfx = new_progress_context ();
239 :
240 : (void)ctrl;
241 : (void)out_fp;
242 :
243 0 : if (is_secured_file (sig_fd))
244 : {
245 0 : fp = NULL;
246 0 : gpg_err_set_errno (EPERM);
247 : }
248 : else
249 0 : fp = iobuf_fdopen_nc (sig_fd, "rb");
250 0 : if (!fp)
251 : {
252 0 : rc = gpg_error_from_syserror ();
253 0 : log_error (_("can't open fd %d: %s\n"), sig_fd, strerror (errno));
254 0 : goto leave;
255 : }
256 :
257 0 : handle_progress (pfx, fp, NULL);
258 :
259 0 : if ( !opt.no_armor && use_armor_filter (fp) )
260 : {
261 0 : afx = new_armor_context ();
262 0 : push_armor_filter (afx, fp);
263 : }
264 :
265 0 : rc = proc_signature_packets_by_fd (ctrl, NULL, fp, data_fd);
266 :
267 0 : if ( afx && afx->no_openpgp_data
268 0 : && (rc == -1 || gpg_err_code (rc) == GPG_ERR_EOF) )
269 0 : rc = gpg_error (GPG_ERR_NO_DATA);
270 :
271 : leave:
272 0 : iobuf_close (fp);
273 0 : release_progress_context (pfx);
274 0 : release_armor_context (afx);
275 0 : return rc;
276 : }
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