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Diffstat (limited to 'g10/verify.c')
| -rw-r--r-- | g10/verify.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/g10/verify.c b/g10/verify.c new file mode 100644 index 0000000..082db89 --- /dev/null +++ b/g10/verify.c @@ -0,0 +1,211 @@ +/* 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; +} |