Eugene Khabarov ekhabarov

My OS X “VPN only” Setup For #30C3

You should never let passwords or private data be transmitted over an untrusted network (your neighbor’s, the one at Starbucks or the company) anyway, but on a hacker congress like the #30C3, this rule is almost vital.

Hackers get bored easily, and when they’re bored, they’re starting to look for things to play with. And a network with several thousand connected users is certainly an interesting thing to play with. Some of them might start intercepting the data on the network or do other nasty things with the packets that they can get.

If these packets are encrypted, messing with them is much harder (but not impossible! – see the end of this article). So you want your packets to be always encrypted. And the best way to do that is by using a VPN.

Target audience

WAL-E needs to be installed on all machines, masters and slaves.

How to install WAL-E

Only one machine, the master, writes WAL segments via continuous archiving. The configuration for the master postgresql.conf is:

archive_mode = on
archive_command = 'envdir /etc/wal-e.d/env wal-e wal-push %p'
archive_timeout = 60

Configuring mutt to work with gmail and yandex

Information used:

So, thanks to authors for ideas and detailed tutorials how to get it working.

Make it real

Ideas are cheap. Make a prototype, sketch a CLI session, draw a wireframe. Discuss around concrete examples, not hand-waving abstractions. Don't say you did something, provide a URL that proves it.

Ship it

Nothing is real until it's being used by a real user. This doesn't mean you make a prototype in the morning and blog about it in the evening. It means you find one person you believe your product will help and try to get them to use it.

	package main

	import (
	"fmt"
	"log"
	"net/http"
	"time"
	)

	// Example SSE server in Golang.

	-- show running queries (pre 9.2)
	SELECT procpid, age(query_start, clock_timestamp()), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(query_start, clock_timestamp()), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

	CREATE OR REPLACE FUNCTION generate_object_id() RETURNS varchar AS $$
	DECLARE
	time_component bigint;
	machine_id int := FLOOR(random() * 16777215);
	process_id int;
	seq_id bigint := FLOOR(random() * 16777215);
	result varchar:= '';
	BEGIN
	SELECT FLOOR(EXTRACT(EPOCH FROM clock_timestamp())) INTO time_component;
	SELECT pg_backend_pid() INTO process_id;

	create table deps_saved_ddl
	(
	deps_id serial primary key,
	deps_view_schema varchar(255),
	deps_view_name varchar(255),
	deps_ddl_to_run text
	);

	create or replace function deps_save_and_drop_dependencies(p_view_schema varchar, p_view_name varchar) returns void as
	$$

	#!/bin/bash

	# This is a draft but it works

	# FIRST (I don't even know if it works but we'll assume yes)
	# sudo launchctl list
	# sudo launchctl disable system/netbiosd
	# sudo launchctl disable system/parsecd
	# sudo launchctl disable system/parentalcontrols.check
	# sudo launchctl disable system/airportd