gnupg/g10/openfile.c

/* openfile.c
 * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
 *               2005 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 <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "util.h"
#include "memory.h"
#include "ttyio.h"
#include "options.h"
#include "main.h"
#include "status.h"
#include "i18n.h"

#ifdef USE_ONLY_8DOT3
#define SKELEXT ".skl"
#else
#define SKELEXT EXTSEP_S "skel"
#endif

#if defined (HAVE_DRIVE_LETTERS) || defined (__riscos__)
#define CMP_FILENAME(a,b) ascii_strcasecmp( (a), (b) )
#else
#define CMP_FILENAME(a,b) strcmp( (a), (b) )
#endif

#ifdef MKDIR_TAKES_ONE_ARG
#undef mkdir
#define mkdir(a,b) mkdir(a)
#endif

/* FIXME:  Implement opt.interactive. */

/****************
 * Check whether FNAME exists and ask if it's okay to overwrite an
 * existing one.
 * Returns: True: it's okay to overwrite or the file does not exist
 *	    False: Do not overwrite
 */
int
overwrite_filep( const char *fname )
{
    if( iobuf_is_pipe_filename (fname) )
	return 1; /* Writing to stdout is always okay */

    if( access( fname, F_OK ) )
	return 1; /* does not exist */

#ifndef HAVE_DOSISH_SYSTEM
    if ( !strcmp ( fname, "/dev/null" ) )
        return 1; /* does not do any harm */
#endif

    /* fixme: add some backup stuff in case of overwrite */
    if( opt.answer_yes )
	return 1;
    if( opt.answer_no || opt.batch )
	return 0;  /* do not overwrite */

    tty_printf(_("File `%s' exists. "), fname);
    if( cpr_get_answer_is_yes("openfile.overwrite.okay",
			       _("Overwrite? (y/N) ")) )
	return 1;
    return 0;
}


/****************
 * Strip know extensions from iname and return a newly allocated
 * filename.  Return NULL if we can't do that.
 */
char *
make_outfile_name( const char *iname )
{
    size_t n;

    if ( iobuf_is_pipe_filename (iname) )
	return xstrdup("-");

    n = strlen(iname);
    if( n > 4 && (    !CMP_FILENAME(iname+n-4, EXTSEP_S "gpg")
		   || !CMP_FILENAME(iname+n-4, EXTSEP_S "pgp")
		   || !CMP_FILENAME(iname+n-4, EXTSEP_S "sig")
		   || !CMP_FILENAME(iname+n-4, EXTSEP_S "asc") ) ) {
	char *buf = xstrdup( iname );
	buf[n-4] = 0;
	return buf;
    }
    else if( n > 5 && !CMP_FILENAME(iname+n-5, EXTSEP_S "sign") ) {
	char *buf = xstrdup( iname );
	buf[n-5] = 0;
	return buf;
    }

    log_info(_("%s: unknown suffix\n"), iname );
    return NULL;
}


/****************
 * Ask for a outputfilename and use the given one as default.
 * Return NULL if no file has been given or it is not possible to
 * ask the user.
 */
char *
ask_outfile_name( const char *name, size_t namelen )
{
    size_t n;
    const char *s;
    char *prompt;
    char *fname;
    char *defname;

    if( opt.batch )
	return NULL;

    s = _("Enter new filename");

    n = strlen(s) + namelen + 10;
    defname = name && namelen? make_printable_string( name, namelen, 0): NULL;
    prompt = xmalloc(n);
    if( defname )
	sprintf(prompt, "%s [%s]: ", s, defname );
    else
	sprintf(prompt, "%s: ", s );
    tty_enable_completion(NULL);
    fname = cpr_get("openfile.askoutname", prompt );
    cpr_kill_prompt();
    tty_disable_completion();
    xfree(prompt);
    if( !*fname ) {
	xfree( fname ); fname = NULL;
	fname = defname; defname = NULL;
    }
    xfree(defname);
    if (fname)
        trim_spaces (fname);
    return fname;
}


/****************
 * Make an output filename for the inputfile INAME.
 * Returns an IOBUF and an errorcode
 * Mode 0 = use ".gpg"
 *	1 = use ".asc"
 *	2 = use ".sig"
 */
int
open_outfile( const char *iname, int mode, IOBUF *a )
{
  int rc = 0;

  *a = NULL;
  if( iobuf_is_pipe_filename (iname) && !opt.outfile ) {
    *a = iobuf_create(NULL);
    if( !*a ) {
      log_error(_("can't open `%s': %s\n"), "[stdout]", strerror(errno) );
      rc = G10ERR_CREATE_FILE;
    }
    else if( opt.verbose )
      log_info(_("writing to stdout\n"));
  }
  else {
    char *buf = NULL;
    const char *name;
    
    if( opt.dry_run )
      name = "/dev/null";
    else if( opt.outfile )
      name = opt.outfile;
    else {
#ifdef USE_ONLY_8DOT3
      if (opt.mangle_dos_filenames)
        {
          /* It is quite common DOS system to have only one dot in a
           * a filename So if we have something like this, we simple
           * replace the suffix execpt in cases where the suffix is
           * larger than 3 characters and not the same as.
           * We should really map the filenames to 8.3 but this tends to
           * be more complicated and is probaly a duty of the filesystem
           */
          char *dot;
          const char *newsfx = mode==1 ? ".asc" :
                               mode==2 ? ".sig" : ".gpg";
          
          buf = xmalloc(strlen(iname)+4+1);
          strcpy(buf,iname);
          dot = strchr(buf, '.' );
          if ( dot && dot > buf && dot[1] && strlen(dot) <= 4
				  && CMP_FILENAME(newsfx, dot) )
            {
              strcpy(dot, newsfx );
            }
          else if ( dot && !dot[1] ) /* don't duplicate a dot */
            strcpy( dot, newsfx+1 );
          else
            strcat ( buf, newsfx );
        }
      if (!buf)
#endif /* USE_ONLY_8DOT3 */
        {
          buf = xmalloc(strlen(iname)+4+1);
          strcpy(stpcpy(buf,iname), mode==1 ? EXTSEP_S "asc" :
		                   mode==2 ? EXTSEP_S "sig" : EXTSEP_S "gpg");
        }
      name = buf;
    }

    rc = 0;
    while( !overwrite_filep (name) )
      {
        char *tmp = ask_outfile_name (NULL, 0);
        if ( !tmp || !*tmp )
          {
            xfree (tmp);
            rc = G10ERR_FILE_EXISTS;
            break;
          }
        xfree (buf);
        name = buf = tmp;
      }
    
    if( !rc )
      {
        if (is_secured_filename (name) )
          {
            *a = NULL;
            errno = EPERM;
          }
        else
          *a = iobuf_create( name );
        if( !*a )
          {
            log_error(_("can't create `%s': %s\n"), name, strerror(errno) );
            rc = G10ERR_CREATE_FILE;
          }
        else if( opt.verbose )
          log_info(_("writing to `%s'\n"), name );
      }
    xfree(buf);
  }

  if (*a)
    iobuf_ioctl (*a,3,1,NULL); /* disable fd caching */

  return rc;
}


/****************
 * Try to open a file without the extension ".sig" or ".asc"
 * Return NULL if such a file is not available.
 */
IOBUF
open_sigfile( const char *iname, progress_filter_context_t *pfx )
{
    IOBUF a = NULL;
    size_t len;

    if( !iobuf_is_pipe_filename (iname) ) {
	len = strlen(iname);
	if( len > 4 && ( !strcmp(iname + len - 4, EXTSEP_S "sig")
                        || ( len > 5 && !strcmp(iname + len - 5, EXTSEP_S "sign") )
                        || !strcmp(iname + len - 4, EXTSEP_S "asc")) ) {
	    char *buf;
	    buf = xstrdup(iname);
	    buf[len-(buf[len-1]=='n'?5:4)] = 0 ;
	    a = iobuf_open( buf );
            if (a && is_secured_file (iobuf_get_fd (a)))
              {
                iobuf_close (a);
                a = NULL;
                errno = EPERM;
              }
	    if( a && opt.verbose )
		log_info(_("assuming signed data in `%s'\n"), buf );
	    if (a && pfx)
	      handle_progress (pfx, a, buf);
            xfree(buf);
	}
    }
    return a;
}

/****************
 * Copy the option file skeleton to the given directory.
 */
static void
copy_options_file( const char *destdir )
{
    const char *datadir = GNUPG_DATADIR;
    char *fname;
    FILE *src, *dst;
    int linefeeds=0;
    int c;
    mode_t oldmask;
    int esc = 0;
    int any_option = 0;

    if( opt.dry_run )
	return;

    fname = xmalloc( strlen(datadir) + strlen(destdir) + 15 );
    strcpy(stpcpy(fname, datadir), DIRSEP_S "options" SKELEXT );
    src = fopen( fname, "r" );
    if (src && is_secured_file (fileno (src)))
      {
        fclose (src);
        src = NULL;
        errno = EPERM;
      }
    if( !src ) {
	log_error(_("can't open `%s': %s\n"), fname, strerror(errno) );
	xfree(fname);
	return;
    }
    strcpy(stpcpy(fname, destdir), DIRSEP_S "gpg" EXTSEP_S "conf" );
    oldmask=umask(077);
    if ( is_secured_filename (fname) )
      {
        dst = NULL;
        errno = EPERM;
      }
    else
      dst = fopen( fname, "w" );
    umask(oldmask);
    if( !dst ) {
	log_error(_("can't create `%s': %s\n"), fname, strerror(errno) );
	fclose( src );
	xfree(fname);
	return;
    }

    while( (c=getc(src)) != EOF ) {
	if( linefeeds < 3 ) {
	    if( c == '\n' )
		linefeeds++;
	}
	else {
	    putc( c, dst );
            if (c== '\n')
                esc = 1;
            else if (esc == 1) {
                if (c == ' ' || c == '\t')
                    ;
                else if (c == '#')
                    esc = 2;
                else 
                    any_option = 1;
            }
        }
    }
    fclose( dst );
    fclose( src );
    log_info(_("new configuration file `%s' created\n"), fname );
    if (any_option)
        log_info (_("WARNING: options in `%s'"
                    " are not yet active during this run\n"),
                  fname);
    xfree(fname);
}


void
try_make_homedir( const char *fname )
{
    const char *defhome = GNUPG_HOMEDIR;

    /* Create the directory only if the supplied directory name
     * is the same as the default one.  This way we avoid to create
     * arbitrary directories when a non-default homedirectory is used.
     * To cope with HOME, we do compare only the suffix if we see that
     * the default homedir does start with a tilde.
     */
    if( opt.dry_run || opt.no_homedir_creation )
	return;

    if ( ( *defhome == '~'
           && ( strlen(fname) >= strlen (defhome+1)
                && !strcmp(fname+strlen(fname)-strlen(defhome+1),
                           defhome+1 ) ))
         || ( *defhome != '~'
              && !compare_filenames( fname, defhome ) )
        ) {
	if( mkdir( fname, S_IRUSR|S_IWUSR|S_IXUSR ) )
	    log_fatal( _("can't create directory `%s': %s\n"),
					fname,	strerror(errno) );
	else if( !opt.quiet )
	    log_info( _("directory `%s' created\n"), fname );
	copy_options_file( fname );
/*  	log_info(_("you have to start GnuPG again, " */
/*  		   "so it can read the new configuration file\n") ); */
/*  	g10_exit(1); */
    }
}