sub start_file_download
{
	return "Bad Encryption Key" unless(decrypt_param(pop(@_)) eq "Encryption checking OK");
	my ($url, $destination, $filename, $action, $post_script) = &decrypt_params(@_);
	logger
	  "Starting to download URL $url. Destination: $destination - Filename: $filename";

	if (!-e $destination)
	{
		logger "Creating destination directory.";
		if (!mkpath $destination )
		{
			logger "Could not create destination '$destination' directory : $!";
			return -2;
		}
	}

	my $download_file_path = Path::Class::File->new($destination, "$filename");

	my $pid = fork();
	if (not defined $pid)
	{
		logger "Could not allocate resources for download.";
		return -3;
	}

	# Only the forked child goes here.
	elsif ($pid == 0)
	{
		my $ua = LWP::UserAgent->new( ssl_opts => { verify_hostname => 0,
													SSL_verify_mode => 0x00 } );
		$ua->agent('Mozilla/5.0');
		my $response = $ua->get($url, ':content_file' => "$download_file_path");

		if ($response->is_success)
		{
			logger "Successfully fetched $url and stored it to $download_file_path. Retval: ".$response->status_line;

			if (!-e $download_file_path)
			{
				logger "File $download_file_path does not exist.";
				exit(0);
			}

			if ($action eq "uncompress")
			{
				logger "Starting file uncompress as ordered.";
				uncompress_file_without_decrypt($download_file_path,
												$destination);
			}

			# Run post scripts if any
			if ($post_script ne "")
			{
				logger "1 Running postscript commands.";
				my @postcmdlines = split /[\r\n]+/, $post_script;
				my $postcmdfile = $destination."/".'postinstall.sh';
				open  FILE, '>', $postcmdfile;
				print FILE "cd $destination\n";
				print FILE "while kill -0 $pid >/dev/null 2>&1\n";
				print FILE "do\n";
				print FILE "	sleep 1\n";
				print FILE "done\n";
				foreach my $line (@postcmdlines) {
					print FILE "$line\n";
					logger "1 Postscript command received \"" . $line ."\".";
				}
				print FILE "rm -f $destination/postinstall.sh\n";
				close FILE;
				chmod 0755, $postcmdfile;
				my $screen_id = create_screen_id("post_script", $pid);
				my $cli_bin = create_screen_cmd($screen_id, "bash $postcmdfile");
				system($cli_bin);
			}
		}
		else
		{
			logger
			  "Unable to fetch $url, or save to $download_file_path. Retval: ".$response->status_line;
			exit(0);
		}

		# Child process must exit.
		exit(0);
	}
	else
	{
		sleep 10;
		if ($post_script ne "")
		{
			logger "2 Running postscript commands.";
			my @postcmdlines = split /[\r\n]+/, $post_script;
			my $postcmdfile = $destination."/".'postinstall.sh';
			open  FILE, '>', $postcmdfile;
			print FILE "cd $destination\n";
			print FILE "while kill -0 $pid >/dev/null 2>&1\n";
			print FILE "do\n";
			print FILE "	sleep 1\n";
			print FILE "done\n";
			foreach my $line (@postcmdlines) {
				print FILE "$line\n";
				logger "2 Postscript command received \"" . $line ."\".";
			}
			print FILE "rm -f $destination/postinstall.sh\n";
			close FILE;
			chmod 0755, $postcmdfile;
			my $screen_id = create_screen_id("post_script", $pid);
			sudo_exec_without_decrypt("bash $postcmdfile");
		}
		logger "Download process for $download_file_path has pid number $pid.";
		return "$pid";
	}
}