g10/decrypt.c

   1 /* decrypt.c - verify signed data
   2  * Copyright (C) 1998,1999,2000,2001,2002,2003 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 2 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, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <assert.h>
  27
  28 #include "options.h"
  29 #include "packet.h"
  30 #include "errors.h"
  31 #include "iobuf.h"
  32 #include "keydb.h"
  33 #include "memory.h"
  34 #include "util.h"
  35 #include "main.h"
  36 #include "status.h"
  37 #include "i18n.h"
  38
  39
  40
  41 /****************
  42  * Assume that the input is an encrypted message and decrypt
  43  * (and if signed, verify the signature on) it.
  44  * This command differs from the default operation, as it never
  45  * writes to the filename which is included in the file and it
  46  * rejects files which don't begin with an encrypted message.
  47  */
  48
  49 int
  50 decrypt_message( const char *filename )
  51 {
  52     iobuf_t fp;
  53     armor_filter_context_t afx;
  54     progress_filter_context_t pfx;
  55     int rc;
  56     int no_out=0;
  57
  58     /* open the message file */
  59     fp = iobuf_open(filename);
  60     if( !fp ) {
  61         rc = gpg_error_from_errno (errno);
  62         log_error(_("can't open `%s'\n"), print_fname_stdin(filename));
  63         return rc;
  64     }
  65
  66     handle_progress (&pfx, fp, filename);
  67
  68     if( !opt.no_armor ) {
  69         if( use_armor_filter( fp ) ) {
  70             memset( &afx, 0, sizeof afx);
  71             iobuf_push_filter( fp, armor_filter, &afx );
  72         }
  73     }
  74
  75     if( !opt.outfile ) {
  76         no_out = 1;
  77         opt.outfile = "-";
  78     }
  79     rc = proc_encryption_packets( NULL, fp );
  80     if( no_out )
  81        opt.outfile = NULL;
  82     iobuf_close(fp);
  83     return rc;
  84 }
  85
  86 void
  87 decrypt_messages(int nfiles, char **files)
  88 {
  89   iobuf_t fp;
  90   armor_filter_context_t afx;
  91   progress_filter_context_t pfx;
  92   char *p, *output = NULL;
  93   int rc = 0;
  94
  95   if (opt.outfile)
  96     {
  97       log_error(_("--output doesn't work for this command\n"));
  98       return;
  99
 100     }
 101
 102   while (nfiles--)
 103     {
 104       print_file_status(STATUS_FILE_START, *files, 3);
 105       output = make_outfile_name(*files);
 106       if (!output)
 107         goto next_file;
 108       fp = iobuf_open(*files);
 109       if (!fp)
 110         {
 111           log_error(_("can't open `%s'\n"), print_fname_stdin(*files));
 112           goto next_file;
 113         }
 114
 115       handle_progress (&pfx, fp, *files);
 116
 117       if (!opt.no_armor)
 118         {
 119           if (use_armor_filter(fp))
 120             {
 121               memset(&afx, 0, sizeof afx);
 122               iobuf_push_filter(fp, armor_filter, &afx);
 123             }
 124         }
 125       rc = proc_packets(NULL, fp);
 126       iobuf_close(fp);
 127       if (rc)
 128         log_error("%s: decryption failed: %s\n", print_fname_stdin(*files),
 129                   gpg_strerror (rc));
 130       p = get_last_passphrase();
 131       set_next_passphrase(p);
 132       xfree (p);
 133
 134     next_file:
 135       /* Note that we emit file_done even after an error. */
 136       write_status( STATUS_FILE_DONE );
 137       xfree (output);
 138       files++;
 139     }
 140   set_next_passphrase(NULL);
 141 }
 142