gnupg/g10/openfile.c

/* openfile.c
 *	Copyright (C) 1998, 1999, 2000 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 <gcrypt.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 ".skel"
#endif

#ifdef HAVE_DRIVE_LETTERS
  #define CMP_FILENAME(a,b) stricmp( (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( !fname || (*fname == '-' && !fname[1]) )
	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( (!iname || (*iname=='-' && !iname[1]) ))
	return gcry_xstrdup("-");

    n = strlen(iname);
    if( n > 4 && (    !CMP_FILENAME(iname+n-4,".gpg")
		   || !CMP_FILENAME(iname+n-4,".pgp")
		   || !CMP_FILENAME(iname+n-4,".sig")
		   || !CMP_FILENAME(iname+n-4,".asc") ) ) {
	char *buf = gcry_xstrdup( iname );
	buf[n-4] = 0;
	return buf;
    }
    else if( n > 5 && !CMP_FILENAME(iname+n-5,".sign") ) {
	char *buf = gcry_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 = gcry_xmalloc(n);
    if( defname )
	sprintf(prompt, "%s [%s]: ", s, defname );
    else
	sprintf(prompt, "%s: ", s );
    fname = cpr_get("openfile.askoutname", prompt );
    cpr_kill_prompt();
    gcry_free(prompt);
    if( !*fname ) {
	gcry_free( fname ); fname = NULL;
	fname = defname; defname = NULL;
    }
    gcry_free(defname);
    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( (!iname || (*iname=='-' && !iname[1])) && !opt.outfile ) {
	if( !(*a = iobuf_create(NULL)) ) {
	    log_error(_("%s: can't open: %s\n"), "[stdout]", strerror(errno) );
	    rc = GPGERR_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
	    /* 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 = gcry_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 );
	  #else
	    buf = gcry_xmalloc(strlen(iname)+4+1);
	    strcpy(stpcpy(buf,iname), mode==1 ? ".asc" :
				      mode==2 ? ".sig" : ".gpg");
	  #endif
	    name = buf;
	}

	if( overwrite_filep( name ) ) {
	    if( !(*a = iobuf_create( name )) ) {
		log_error(_("%s: can't create: %s\n"), name, strerror(errno) );
		rc = GPGERR_CREATE_FILE;
	    }
	    else if( opt.verbose )
		log_info(_("writing to `%s'\n"), name );
	}
	else
	    rc = GPGERR_FILE_EXISTS;
	gcry_free(buf);
    }
    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 )
{
    IOBUF a = NULL;
    size_t len;

    if( iname && !(*iname == '-' && !iname[1]) ) {
	len = strlen(iname);
	if( len > 4 && ( !strcmp(iname + len - 4, ".sig")
                        || ( len > 5 && !strcmp(iname + len - 5, ".sign") )
			|| !strcmp(iname + len - 4, ".asc")) ) {
	    char *buf;
	    buf = gcry_xstrdup(iname);
	    buf[len-4] = 0 ;
	    a = iobuf_open( buf );
	    if( opt.verbose )
		log_info(_("assuming signed data in `%s'\n"), buf );
	    gcry_free(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;

    if( opt.dry_run )
	return;

    fname = gcry_xmalloc( strlen(datadir) + strlen(destdir) + 15 );
    strcpy(stpcpy(fname, datadir), "/options" SKELEXT );
    src = fopen( fname, "r" );
    if( !src ) {
	log_error(_("%s: can't open: %s\n"), fname, strerror(errno) );
	gcry_free(fname);
	return;
    }
    strcpy(stpcpy(fname, destdir), "/options" );
    dst = fopen( fname, "w" );
    if( !dst ) {
	log_error(_("%s: can't create: %s\n"), fname, strerror(errno) );
	fclose( src );
	gcry_free(fname);
	return;
    }

    while( (c=getc(src)) != EOF ) {
	if( linefeeds < 3 ) {
	    if( c == '\n' )
		linefeeds++;
	}
	else
	    putc( c, dst );
    }
    fclose( dst );
    fclose( src );
    log_info(_("%s: new options file created\n"), fname );
    gcry_free(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 )
	return;

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