#!/usr/bin/perl
########################################################
#
# This script is intended to provide a means for
# detecting changes made to files, via a regular
# comparison of MD5 hashes to an established
# "baseline". In this respect, it vaguely resembles
# the Tripwire product, hence the name.
#
#
# This script requires perl (duh), Berkeley DBM support
# and the md5 command, which is a standard part of the
# FreeBSD loadout. I'll probably replace this dependency
# with the perl MD5 module shortly.
#
########################################################
########################################################
#
# Usage:
#
# ./slipwire [options] [hashfilename] [file_list]|file1 file2 file3...
#
# The options are as follows:
#	
#	-create		Initialize database file
#
# 	-compare	Compare MD5 hashes to 
#			baseline configuration
#
#       -only           Index only the filenames given,
#                       ie, don't use a list of files.
#
#
# hashfilename is the name of the Berkeley DBM file created
# for storing the filenames and MD5 hashes.
#
# file_list is a text file containing a list of
# paths that you want to index.
#
#
# example:
#
# slipwire.pl -create foo.dbm dir_list.txt
#
#  ...creates foo.dbm and recursively generates 
#  entries and MD5 hashes for all directories listed
#  in dir_list.txt, which is an ascii file containing
#  one path per line
#
# slipwire.pl -only foo.dbm file1 file2 file3 file4
# ...creates foo.dbm but only indexes file1, file2,
# file3 and file4. 
#
# slipwire.pl -compare foo.dbm dir_list.txt
# ...checks the MD5 hashes of the files in 
# dir_list.txt against the current entries
# in foo.dbm, alerting you to changes.
#
# slipwire.pl -compare foo.dbm file1 file2 file3 file4
# ...checks the MD5 hashes of file1, file2,file3, file4
#
# There isn't much in the way of error-checking in this
# yet, but I thought that this might be useful to someone
# even in its current form. I'm still working on it.
#
# This script can be redistributed under the same terms
# as perl itself.
#
# Cheers,
#
# James Quinby 
# jquinby@node.to
#
#######################################################
#######################################################

use DB_File;
use FileHandle;

if ($ENV{USER} ne "root"){
  print "\nSorry, you must be root to run this program.\n\n";
  exit;
}


if ($ARGV[0] =~ /-create/) {
  create();
  exit;
}

if ($ARGV[0] =~ /-compare/) {
  compare();
  exit;
}

if ($ARGV[0] =~ /-only/) {
  only();
  exit;
}

if ($ARGV[0] =~ //) {
  usage();
  exit;
}


sub create {
 print "You chose to create.\n";

 my $file_list = new FileHandle;
 my $i = 0;

 $file_list->open($ARGV[2]); 

 open(FINDPIPE, "$find |");
 $db = tie  %hashfile, "DB_File", $ARGV[1];

my $file_list_line;

 while ($file_list_line = $file_list->getline()){
  chop $file_list_line;
  print "\nCreating hashes for $file_list_line...\n\n";
  
  my $find = "find " . $file_list_line . ' \! -type d -print -exec /sbin/md5 -q {} \;';
  open(FINDPIPE, "$find |");
  my $find_pipe_line;

   while ($find_pipe_line = <FINDPIPE>) {

     $i++;

     my $key = $find_pipe_line;
     chop $key;

     my $value = <FINDPIPE>;
     chop $value;

     print "$key: $value\n";	 	
     $db->put($key, $value);
   }
 }
 print "\nHash database created successfully. $i files entered.\n";

}


sub compare {  
  print "Comparing files in the current hash database.\n\n";

  my $file_list = new FileHandle;
  my $i;
  my $j = 0;

  $db = tie  %hashfile, "DB_File", $ARGV[1];

  $file_list->open($ARGV[1]);

  my $file_list_line;

  while (($key, $old_value) = each %hashfile){ 
    
    $new_value = `md5 -q $key`;
    chop $new_value;

    $i++;

    if ($new_value ne $old_value){

      print "ALERT! FILE CHANGED: $key\n";
      print "old: " . $old_value . "\n";
      print "new: " . $new_value . "\n";
      
      $j++;
	
    }
  }
  print "\nComparison complete. $i files checked with $j alerts.\n\n";
}


sub only {

print "You want to use the ONLY option\n";

my $file_list;
my $i = 0;
my @file_list = splice(@ARGV, 2);


$db = tie  %hashfile, "DB_File", $ARGV[1];
print "\nCreating hashes...\n\n";

while ($file_list = shift @file_list){

    $i++;

    my $key = $file_list;
    chomp $key;  
   
    my $value = `md5 -q $key`;
    chomp $value;



    print "$key: $value\n";	 	
    $db->put($key, $value);
   }
 
 print "\nHash database created successfully. $i files entered.\n";

}



sub usage {
  print "\n";
  print "Usage: slipwire.pl [options] hashfile [file-list|file1 file2 file3...]\n";
  print "\n\n";
  print "Options:\n\n";
  print "-create  \t Initialize the hash.dbm database\n";
  print "-compare \t Check the filesystems listed in [file-list] against the old values\n";
  print "-only\t\t Create index with supplied filenames only\n";
  print "\n";
  print "hashfile is a DBM file created and used for storing the file and MD5 information.";
  print "\n";
  print "file-list is a text file containing paths and/or filenames to be indexed.\n";
  print "\n";
}