doc/en_US.ISO8859-1/captions/2007/meetbsd/brueffer-torprvacy.sbv
2011-05-15 20:41:31 +00:00

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Fortunately my slide will be centered, because
I'll have to change resolutions. I think this works out...
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And, it's about protecting your privacy with FreeBSD and Tor
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and, uh...
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Privacy.
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What I mean here is mostly anonymity
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but there are some other aspects that
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I'll talk about later
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uh, so...
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I want to first talk about who needs anonymity anyway
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Is it just for criminals or some other bad guys, right?
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After this
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anonymization concepts, then Tor. Tor's a, well, a tool
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to, uh...
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anonymize you on the Web. Then I'll talk about what
FreeBSD can do with it
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and what else
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you have to take care of
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when you want to be anonymous on the Web or the Internet
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And uh,
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if time permits I'd like to do a little demonstration
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Ok, so who needs anonymity anyway?
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Anonymity is a pretty vast
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interest to most people
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but it's really important for
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journalists... There was a case in, uh,
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Thailand last year
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when the military coup was going on
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and the journalists in Thailand couldn't really uh
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Journalists couldn't really, uh
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get the information they needed to do their work
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Also, uh, informants
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whistleblowers... people who want to tell you about
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corruption going on in governments and companies
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and don't want to lose their job for it... Dissidents
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Uh, best case
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when in Myanmar
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last few weeks ago
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When the
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all the Buddhists monks were going to the streets and uh,
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the Internet was heavily censored
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It was really dangerous to do anything on the Internet
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So, so umm
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socially sensitive information, like when you want to uh,
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when you were abused
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and want to talk to other people about it
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you don't... naturally you don't want other people to
know who you are
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as it will be very embarrassing
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Also Law Enforcement, ah
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for example, uh, when you want to set up a
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an anonymous tipline for crime reporting
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And uh, also companies that want to, uh
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research competition, as one case that, uh
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that a company went to check the, uh
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website competition and they noticed when they used Tor
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that, uh, they were actually getting a different website
when they
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uh, were coming from the corporate LAN
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than anyone else was getting, so ah,
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it's a good way to, uh,
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check out... competition like this
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Also military
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actually military was one of the, uh
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original
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driving forces behind the
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anonymization research.
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And maybe you
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may have heard of the European Union
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Data Retention Directive?
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Where, umm
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collection data gets stored
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six to twenty-four months? Depends on the limitation
on the different nations
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Two weeks back this was, uh,
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the law was passed in Germany
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So, uh
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from first January on,
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every connection, phone connection,
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SMS, IP connections,
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email, or the dial-in data needs to be stored
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by providers for six months
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And, uh,
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sooner or later it's going to be in Poland as well
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[talking]
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Well, you're part of the Euro Union now, so ah, welcome!
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Okay, uh
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that's a
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Maybe you want to hide what interests you have and uh,
who you talk to, I mean uh,
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like all of you know the Internet isn't very
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secure in the first place so your ISP can see who you're
talking to
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if they bother to find out
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Yeah, and also
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criminals, but they already do illegal stuff and they
don't care about
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doing more illegal stuff to stay anonymous, right? They can
steal people's identities, they can rent botnets or
create them in the first place
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and uh,
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or just
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crack one of the thousands of Windows computers online,
no big deal
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So, uh
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Criminals already do this and uh,
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the normal
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citizens can't do this so...
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So all the groups that need anonymization are very different,
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but they all have the same goal, and uh
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that's also one of the
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key concepts of
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anonymization
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you can't really
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stay anonymous on your own
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you need the help of more people
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and uh,
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the more diverse the group that needs
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anonymity, the better
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Ok, so on to talking about two
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anonymization concepts
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Proxy? Everyone here probably knows how a proxy works,
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LANs connect to the proxy and request
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a website or whatever and the proxy
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just passes it on and pass through
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Proxys are fast and simple but it's really a single point of
failure, like uh,
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when law enforcement or anyone else wants to
uh, know
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who you're talking to they just
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get a subpoena or
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break into the computer room or whatever
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It's pretty easy
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Second anonymization concept is MIX,
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it's really old from nineteen eighty one
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So you can see, uh,
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how long the research in this area is going on
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The MIX is kind of similar to a proxy
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Like, trying to connect to it to send the messages
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and the MIX collects them
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and coalesces them
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Like, it puts them all
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into coming sites and uhm,
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you see here it
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shuffles them. It waits
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until there's enough data in it and just
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shuffles them and sends them back out so
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um, this is to protect against correlation attacks.
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But second in...
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Oh yeah, and
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when you actually put several MIXes uh
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behind them; it's a MIX cascade and uh,
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between mixes is also
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encryption going on, uh, the first
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or the client which
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you could see here if the slides would be centered, uh,
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what else gets the
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public keys of all the mixes
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and encrypts the message first for each of them
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and each mix removes one encryption layer and
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uh, the last one actually passes on the message unencrypted
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and uhm, loop back backwards the same
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So, as you can probably imagine,
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if you wait until you have enough messages, ah, and all
public key encryption
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is going pretty slow
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and uh,
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this concept is mostly used for
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remailers like
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MixMinion, for example uh
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where it's not really a possib... um
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it's not really important
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if the message is a couple of seconds
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late or something, but it's not really
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great for uh, for
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low latency connections,
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like web routing for example
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but what's good about it it's uh
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distributed trust uh,
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just one these MIXes has to be secure to actually
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anonymize the whole connection
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so it's slow but it's
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distributed trust, which is good.
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So, I want to introduce Tor
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Tor stands for The Onion Router.
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It's a concept that is actually built on
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both these concepts
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MIXes and proxies.
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It's a TCP-Overlay network,
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that means you can, uh
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channel any
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TCP connection through it
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theoretically
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Uh, theoretically I will explain
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a couple of slides later
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It provides a SOCKS interface so you don't need any uh,
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special application proxies like any application that uses
SOCKS interface can just
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talk to Tor
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and it's available on, um, all major platforms
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What is uh, especially important it's available in Windows
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Because, uhm, like I said earlier once
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you want a really diverse,
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really diverse group of users
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so you actually need uh,
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the normal user
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not just geeks.
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Um, well it aims to uhm
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combine the positive attributes of
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proxies and MIXes
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Like, proxies are fast, but
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seem prone to failure
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and MIXes
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distributed trust, you want to combine them
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so uh
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Fast, uh, Tor uses not only public key
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encryption but also session keys
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so it's symmetrically encrypted.
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So uh
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all the connection set up is this public key so you just, uh
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authentication and stuff
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And uh, the actual communication that's going on later
is always symmetrically encrypted
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And uh, so it's also TCP multiplexing
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so you can run
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several TCP connections through one
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virtual Tor connection.
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And the design goals are
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yeah
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deployability
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like dums want the user to actually have
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to patch his PC off the Operating System or something
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just be in a... workable state really fast.
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Um, usability,
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so you get the uh,
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normal users
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not just the geeks. Flexibility, uhm
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it's aimed to
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enable more research
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in this whole area.
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So, uh
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the protocol Tor users
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should be really flexible
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And uh, for simplicity it's a security application and
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well complexity doesn't play well with uh,
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security
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So, this uh,
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it's how Tor works, more or less
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Dave is uh, a directory server,
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it uh, caches information about the network state
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and uh, which Tor servers are available in the network
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and uh
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Alice downloads
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this whole list from Dave
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you see the Tor nodes with the plus here?
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Through this random
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tree of service
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when she wants to talk to Jane
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for example
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The first one is the entry node, middleman nodes, and the
uh exit nodes, I will leave these for later
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uh, so this
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Alice talks to the entry node
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there's a connection that is going on and is public key
encrypted
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and they establish a session key and same
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thing goes on
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between these two and these two so they can communicate
later on
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What's really important here
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is the last connection here
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is actually unencrypted.
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I will talk about it later
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So it has to be unencrypted
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so you can actually get your request through
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This is a virtual circuit
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that gets established and uh
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every, every
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ten minutes
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a new circuit is built
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when a new website, when a new request comes through, so uh
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this one stays, all these connections above stay
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in this circuit
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and after ten
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when after ten minutes, ah
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Alice wants to talk to Jane, a new circuit is built
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and uh, this is important
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to get strong
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anonymity
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in case one connection is compromised, for example.
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And these ten minutes
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are really an arbitrary value,
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you can choose anything
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you have to do the research
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which value is best and so
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ten minutes is compromised.
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With Tor you get exit policies,
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this is important for the exit node
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the one which actually sends the uh,
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original request to the destination server
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and huh
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you can control which
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TCP connections you want
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to allow from your own node if you want
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As default policy which uh
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blocks SMTP and NNTP to prevent uh
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spamming and all stuff
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but you can actually allow
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SMTP if you want
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and there's some other ports blocked
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but the rest of it works so
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HTTP SSH
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all the important stuff
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that you would want to anonymize just works
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and uh, if you uh
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this is important for uh, if you
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want to run you own node, uh
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what kind of node you actually want to run
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if you look at the picture, uh earlier
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there's these three different nodes: entry node,
middleman node, and exit node
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and uh, which node you want to run
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depends on how many problems you want afterwards
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I will talk about it later uh
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this one,
0:15:40.970,0:15:46.950
the exit node actually forwards the uh, requested date, uh
0:15:46.950,0:15:47.700
depends upon what
0:15:47.700,0:15:51.570
what the user actually uh wants, that's
0:15:51.570,0:15:52.830
if the user uh
0:15:52.830,0:15:58.020
Alice in this case uh
0:15:58.020,0:16:02.080
insults someone out on a web forum, then uh the uh
0:16:02.080,0:16:03.470
administrator of the forum will see the IP address
0:16:03.470,0:16:05.340
of the
0:16:05.340,0:16:11.230
exit node in his logs and not the one
0:16:11.230,0:16:15.330
of Alice so uh he's going to have the problems later on
0:16:15.330,0:16:18.250
so I will talk about it later
0:16:18.250,0:16:21.600
but you have to keep this in mind
0:16:21.600,0:16:28.600
And uh, keep up everything and uh we can play the role of
entry nodes and middleman nodes
0:16:30.170,0:16:37.170
which is also important
0:16:39.130,0:16:42.930
Special feature of Tor are hidden services
0:16:42.930,0:16:45.850
these are services which can be
0:16:45.850,0:16:46.990
accessed
0:16:46.990,0:16:49.420
without having the IP address of them
0:16:49.420,0:16:50.960
so uh
0:16:50.960,0:16:56.300
you can't really find them physically
0:16:56.300,0:16:57.880
So if you want to run a
0:16:57.880,0:16:59.720
hidden service you can do it from anywhere
0:16:59.720,0:17:01.850
You can even do it from inside this private network here
0:17:01.850,0:17:05.950
You can set up a service and everyone in the outside world
can actually access it
0:17:05.950,0:17:07.770
even if you don't have the rights to do
0:17:07.770,0:17:11.330
port forwarding or something
0:17:11.330,0:17:13.580
uh, this is really important to, uh
0:17:13.580,0:17:15.690
resist Denial of Service, for example
0:17:15.690,0:17:20.160
Because every uh,
0:17:20.160,0:17:20.519
every client that wants to
0:17:20.519,0:17:22.829
access the service uh,
0:17:22.829,0:17:25.700
gets a different route in the network
0:17:25.700,0:17:26.529
and uh, it's hard
0:17:26.529,0:17:28.460
to actually uh
0:17:28.460,0:17:31.970
DOS it. And it's also important to
0:17:31.970,0:17:33.610
resist censorship
0:17:33.610,0:17:38.510
And the addresses look like this:
0:17:38.510,0:17:43.280
it's really a hash of a public key
0:17:43.280,0:17:47.340
and each hidden service is actually, well, identified
0:17:47.340,0:17:53.300
by a public key
0:17:53.300,0:17:59.000
This how it works, uhm, yet Alice the client
0:17:59.000,0:18:02.170
and the hidden server, Bob.
0:18:02.170,0:18:04.120
And if Bob wants to, uh,
0:18:04.120,0:18:07.640
wants to set up a service,
0:18:07.640,0:18:08.159
he chooses three introduction points
0:18:08.159,0:18:09.899
out of the whole mass
0:18:09.899,0:18:11.920
of Tor servers.
0:18:11.920,0:18:18.920
And Bob has the public key to identify the service,
and uh he sends
0:18:22.530,0:18:26.860
this public key and the list of three introduction
points to the directory server.
0:18:26.860,0:18:28.740
Now Alice wants to uh,
0:18:28.740,0:18:31.610
connect to Bob, the first the first thing she does
0:18:31.610,0:18:34.480
is download this
0:18:34.480,0:18:38.910
this list with the introduction points and the uh
0:18:38.910,0:18:45.910
public key from the directory server. After that, uh
0:18:50.120,0:18:54.299
she chooses one of the uh introduction points
0:18:54.299,0:18:55.930
and uh,
0:18:55.930,0:19:02.920
posts a circle rendezvous cookie there. A piece of
data so uh, she can, uh
0:19:02.920,0:19:05.480
identify herself
0:19:05.480,0:19:06.900
and uh, she also
0:19:06.900,0:19:07.860
gives the introduction point
0:19:07.860,0:19:14.500
the address of her random rendezvous point that
Alice has chosen
0:19:14.500,0:19:18.550
so what happens then is uh, Bob notices that uh,
0:19:18.550,0:19:23.760
some data has been stored in the introduction point
0:19:23.760,0:19:28.160
and Alice and Bob uh,
0:19:28.160,0:19:31.230
make a rendezvous point, and
0:19:31.230,0:19:34.940
Bob uses this, this uh
0:19:34.940,0:19:36.700
rendezvous cookie to
0:19:36.700,0:19:38.180
actually identify himself on the rendezvous point
0:19:38.180,0:19:39.990
and after that
0:19:39.990,0:19:46.990
all the connection of data runs through this rendezvous point.
0:19:50.870,0:19:53.180
uh, if time permits I'll actually uh,
0:19:53.180,0:19:54.710
set up a rendezvous
0:19:54.710,0:19:55.960
a hidden service here
0:19:55.960,0:19:59.120
so you can actually see how it works
0:19:59.120,0:20:06.120
I'll also demonstrate Tor, like I said
0:20:08.800,0:20:09.770
uh, there's some legal issues to be uhm
0:20:09.770,0:20:12.450
recognized, uh. As you can imagine, Tor may be
forbidden in some
0:20:12.450,0:20:14.880
countries; especially totalitarian countries
0:20:14.880,0:20:17.530
which censor the Internet anyway
0:20:17.530,0:20:18.719
and uh,
0:20:18.719,0:20:21.030
you may get into trouble for using Tor
0:20:21.030,0:20:25.580
practically, anyone knows this
0:20:25.580,0:20:27.580
there can be crypto restrictions
0:20:27.580,0:20:29.070
for example Great Britain, the uh
0:20:29.070,0:20:33.200
RIPA act, I'm not even sure what it stands for
0:20:33.200,0:20:36.140
but basically says that uh,
0:20:36.140,0:20:37.510
if the government wants,
0:20:37.510,0:20:40.410
then you have to give up your crypto keys
0:20:40.410,0:20:42.910
so they can decrypt it later
0:20:42.910,0:20:47.860
and uh, yeah, it's not really great
0:20:47.860,0:20:50.010
and actually last week was the first case
0:20:50.010,0:20:52.890
when this was actually used in
0:20:52.890,0:20:56.600
Great Britain
0:20:56.600,0:21:00.720
Uh, there can be special laws like in Germany
0:21:00.720,0:21:03.480
sort of like a hacker paragraph
0:21:03.480,0:21:06.990
It's just a nickname, it has some cryptic legal name
0:21:06.990,0:21:07.940
uh, in reality
0:21:07.940,0:21:11.090
and it says that uh
0:21:11.090,0:21:14.570
you're liable if you, uh,
0:21:14.570,0:21:17.360
if you give people access to tools
0:21:17.360,0:21:20.020
that they can use to uh,
0:21:20.020,0:21:22.270
well, to do illegal stuff.
0:21:22.270,0:21:23.630
More or less.
0:21:23.630,0:21:27.080
It's really uh,
0:21:27.080,0:21:29.080
not concrete and no one really...
0:21:29.080,0:21:30.440
it could uh,
0:21:30.440,0:21:31.929
it could
0:21:31.929,0:21:36.669
restrict anything. From a map to a
0:21:36.669,0:21:39.210
to God know what Network tools.
0:21:39.210,0:21:40.880
and uh
0:21:40.880,0:21:43.559
But it was actually, it was actually passed so no one
really knows
0:21:43.559,0:21:45.510
what's the, uhm
0:21:45.510,0:21:46.490
what's really
0:21:46.490,0:21:50.260
restrict by it. So Tor could be restricted
0:21:50.260,0:21:55.590
by it, because it could really enable people to do
illegal stuff,
0:21:55.590,0:21:58.640
but no one really knows
0:21:58.640,0:22:00.990
and uh, the biggest Tor
0:22:00.990,0:22:02.250
problem is
0:22:02.250,0:22:07.480
that, uh
0:22:07.480,0:22:10.180
when uh, when it actually gets sent to a Tor network
0:22:10.180,0:22:13.210
the uh, the
0:22:13.210,0:22:14.669
IP address that
0:22:14.669,0:22:16.210
gets sent
0:22:16.210,0:22:17.220
well that's what the destination server
0:22:17.220,0:22:19.090
actually sees
0:22:19.090,0:22:21.200
is one of the exit nodes.
0:22:21.200,0:22:22.380
So when, uh
0:22:22.380,0:22:23.740
when a client
0:22:23.740,0:22:26.090
actually causes trouble,
0:22:26.090,0:22:26.950
then the one
0:22:26.950,0:22:29.790
that gets into trouble
0:22:29.790,0:22:32.460
is the exit nodes provider. And uh,
0:22:32.460,0:22:33.560
so stuff that gets done
0:22:33.560,0:22:38.620
for torment purpose like sending ransom mails or uh,
0:22:38.620,0:22:40.480
distributing illegal stuff
0:22:40.480,0:22:42.040
and it, this all happened
0:22:42.040,0:22:43.500
and, if you are
0:22:43.500,0:22:46.460
unlucky as an exit node operator
0:22:46.460,0:22:47.109
your server gets seized or something
0:22:47.109,0:22:52.059
and uh,
0:22:52.059,0:22:55.530
that's random stuff that can happen
0:22:55.530,0:22:56.540
So uh,
0:22:56.540,0:22:59.559
as an exit nodes provider you can get
0:22:59.559,0:23:03.690
letters from Law Enforcement agencies, and uh
0:23:03.690,0:23:05.649
What are you doing there?
0:23:05.649,0:23:06.830
Maybe some illegal stuff?
0:23:06.830,0:23:10.040
And you have to explain to them that you are
0:23:10.040,0:23:12.260
providing Tor server and
0:23:12.260,0:23:13.980
it wasn't you
0:23:13.980,0:23:15.120
and stuff.
0:23:15.120,0:23:18.020
For example the FBI
0:23:18.020,0:23:19.960
in America
0:23:19.960,0:23:23.580
actually knows what you're talking about when you tell them
0:23:23.580,0:23:24.580
that you're using Tor...
0:23:24.580,0:23:26.019
so, uh
0:23:26.019,0:23:26.600
they won't bother.
0:23:26.600,0:23:28.810
But in Germany the uh,
0:23:28.810,0:23:34.830
Law Enforcement agencies, actually are, so so
0:23:34.830,0:23:41.440
depends on what kind of guy you're actually talking to
0:23:41.440,0:23:47.120
So what's... What kind of role plays FreeBSD here?
0:23:47.120,0:23:51.880
uh, FreeBSD is really well suited as a Tor node, uh
0:23:51.880,0:23:55.490
when you're operating the client you just want to use the
network, uh
0:23:55.490,0:23:57.830
it doesn't matter what kind of system you use
0:23:57.830,0:23:59.150
and it shouldn't matter
0:23:59.150,0:24:00.830
This is one of the, uh
0:24:00.830,0:24:03.130
like I said earlier one of the design
0:24:03.130,0:24:05.500
criteria of Tor
0:24:05.500,0:24:08.610
so it doesn't matter if you're using Windows or FreeBSD.
0:24:08.610,0:24:09.929
But if you're using the Tor
0:24:09.929,0:24:14.290
as actually uh,
0:24:14.290,0:24:17.320
the security of others depends on your node
0:24:17.320,0:24:20.690
and uh,
0:24:20.690,0:24:22.950
when you're operating a node is important to
0:24:22.950,0:24:25.310
have Operational Security
0:24:25.310,0:24:25.980
and Jails
0:24:25.980,0:24:27.550
are really great for this,
0:24:27.550,0:24:29.980
so you can run a Tor server in Jail.
0:24:29.980,0:24:32.950
It's also Disk and Swap encryption
0:24:32.950,0:24:38.010
which is important, especially the swap encryption. And uh,
0:24:38.010,0:24:39.390
there's also audit
0:24:39.390,0:24:40.740
and the MAC framework
0:24:40.740,0:24:43.780
when you want to run your installation
0:24:43.780,0:24:46.220
What's also nice,
0:24:46.220,0:24:46.659
Tor servers do a lot of public key encryption
0:24:46.659,0:24:48.440
and it's pretty slow
0:24:48.440,0:24:49.480
so it's great to have
0:24:49.480,0:24:54.750
hardware acceleration for this.
0:24:54.750,0:24:56.160
And uh, probably the biggest feature:
0:24:56.160,0:25:03.160
Well maintained Tor-related ports.
0:25:04.060,0:25:07.390
There is the main port, security/Tor
0:25:07.390,0:25:11.370
Which is a client and server if you want to run
0:25:11.370,0:25:13.610
a network node, or just a client.
0:25:13.610,0:25:15.210
There's tor-devel
0:25:15.210,0:25:16.450
and these are really up to date, uhm
0:25:16.450,0:25:22.830
Tor development happens really fast
0:25:22.830,0:25:23.710
and the ports get updated
0:25:23.710,0:25:30.710
pretty soon after a release is made.
0:25:32.050,0:25:39.050
There's Privoxy, which is an uhm web proxy and uhm,
we'll use it later when we do the demonstration
0:25:41.320,0:25:44.310
And there's net management Vidalia which is a
graphical frontend
0:25:44.310,0:25:47.200
also for Windows
0:25:47.200,0:25:48.260
and, uhm
0:25:48.260,0:25:53.929
there's trans-proxy-tor
0:25:53.929,0:25:58.650
which enables you to actually
0:25:58.650,0:25:59.560
uhm, well there's some
0:25:59.560,0:26:02.080
badly written applications out there
0:26:02.080,0:26:05.280
that do stuff that's
0:26:05.280,0:26:07.510
that makes it hard for Tor to
0:26:07.510,0:26:08.860
anonymize them
0:26:08.860,0:26:10.810
and you can use trans-proxy-tor
0:26:10.810,0:26:15.510
to tunnel such connections through the Tor network.
0:26:15.510,0:26:20.580
We'll actually talk about them in the next slide.
0:26:20.580,0:26:24.960
Yeah. What else do you need to take care of
besides running Tor?
0:26:24.960,0:26:27.130
Uh, there's name resolution, uh...
0:26:27.130,0:26:28.760
Some applications just
0:26:28.760,0:26:30.500
bypass the configured proxy
0:26:30.500,0:26:34.500
for example Firefox versions below version 1.5,
0:26:34.500,0:26:35.700
which send every data,
0:26:35.700,0:26:38.320
all data through the proxy
0:26:38.320,0:26:38.909
but not
0:26:38.909,0:26:40.880
DNS requests
0:26:40.880,0:26:44.380
so they actually result in mistrust
0:26:44.380,0:26:46.450
and uh, so yeah
0:26:46.450,0:26:49.280
the connection is actually anonymized
0:26:49.280,0:26:51.080
but the DNS server
0:26:51.080,0:26:52.250
really knows
0:26:52.250,0:26:53.870
uh, who you were talking to
0:26:53.870,0:27:00.870
and this is really the intention of Tor, but uh,
newer versions actually takes.
0:27:03.130,0:27:04.240
Uh, there's the usual
0:27:04.240,0:27:09.990
cookies, web-bugs, referrer and stuff, uhm
0:27:09.990,0:27:11.800
which uh,
0:27:11.800,0:27:13.530
sites can use to check which
0:27:13.530,0:27:20.530
websites you're visiting, and it's just the
usual disabling stuff
0:27:20.549,0:27:23.250
Privoxy is a great tool to
0:27:23.250,0:27:28.160
normalize HTTP traffic.
0:27:28.160,0:27:30.010
And it's also great to uhm, well filter off advertising
0:27:30.010,0:27:36.370
and stuff.
0:27:36.370,0:27:38.660
This should be really obvious
0:27:38.660,0:27:41.110
but apparently is not. Uhm,
0:27:41.110,0:27:43.770
There's so many people who don't realize
0:27:43.770,0:27:44.700
that the last connection
0:27:44.700,0:27:46.380
chain is actually unencrypted
0:27:46.380,0:27:50.900
if you're using, uh
0:27:50.900,0:27:53.250
if you're not using a secure protocol.
0:27:53.250,0:27:54.100
So,
0:27:54.100,0:27:56.440
people actually uhm,
0:27:56.440,0:27:59.430
get their mail through POP3 or something
0:27:59.430,0:28:04.870
and the exit nodes can just run desniff and sniff
out all the passwords.
0:28:04.870,0:28:11.870
And it's really surprising how many people uh, do this.
0:28:13.450,0:28:16.700
So, lesson learned: use secure protocols.
0:28:16.700,0:28:18.220
There are also other services that require
0:28:18.220,0:28:20.630
registration, for example,
0:28:20.630,0:28:22.040
with your e-mail address or
0:28:22.040,0:28:23.640
personal
0:28:23.640,0:28:25.360
data
0:28:25.360,0:28:27.590
and uh, well
0:28:27.590,0:28:28.620
if you're using Tor and you
0:28:28.620,0:28:35.620
actually log on to one of those services, Tor can help you
0:28:40.850,0:28:42.440
So, once I actually demonstrate how
0:28:42.440,0:28:49.440
this all works.
0:29:13.550,0:29:15.520
Uh, I've installed Tor and
0:29:15.520,0:29:22.520
Privoxy on this system
0:29:24.810,0:29:27.180
Config files are on the usual places.
0:29:27.180,0:29:34.180
And if you read this, this little... small...
Is this alright?
0:29:46.950,0:29:50.600
So there is this torrc sample file
0:29:50.600,0:29:57.600
which we can use
0:30:07.020,0:30:08.370
so this
0:30:08.370,0:30:10.340
there's the usual commands and stuff
0:30:10.340,0:30:11.030
and this,
0:30:11.030,0:30:15.720
much stuff that we don't need for the moment
0:30:15.720,0:30:19.840
there's this uh,
0:30:19.840,0:30:24.220
SOCKS port and SOCKS listen address information
0:30:24.220,0:30:31.220
that just
0:30:32.770,0:30:34.659
tells you where to connect your uh,
0:30:34.659,0:30:36.679
your proxy to
0:30:36.679,0:30:38.200
so this is the information that we use in Privoxy to
0:30:38.200,0:30:41.450
access Tor.
0:30:41.450,0:30:42.190
Uhm,
0:30:42.190,0:30:45.320
all we have to do to actually use Tor is
0:30:45.320,0:30:48.970
copy over the config file.
0:30:48.970,0:30:55.970
Start the service
0:31:04.110,0:31:10.570
so, it tells us it's running... Now we have to
0:31:10.570,0:31:12.350
take a look at Privoxy
0:31:20.880,0:31:25.120
There's also lots of stuff that we don't need
right now
0:31:25.120,0:31:30.360
What we need is the uh,
0:31:30.360,0:31:31.740
we need to tell
0:31:31.740,0:31:33.809
Privoxy uh,
0:31:33.809,0:31:40.809
where to send connection requests.
0:31:51.740,0:31:53.659
Ok, I've actually entered this earlier
0:31:53.659,0:31:54.860
uhm,
0:31:54.860,0:31:58.700
all it says is uh,
0:31:58.700,0:32:03.490
forward all requests to
0:32:03.490,0:32:10.490
the uh, SOCKS client
0:32:13.020,0:32:20.020
So we just start
0:32:34.120,0:32:38.870
Ok, so we are all set
0:32:38.870,0:32:40.480
Now we can just do
0:32:40.480,0:32:47.480
everything with our browser
0:32:50.790,0:32:52.029
Startup time sucks a bit
0:32:52.029,0:32:59.029
because of my external drive
0:33:06.860,0:33:08.070
okay, uh
0:33:08.070,0:33:11.470
proxy settings
0:33:11.470,0:33:16.140
we just put in our Privoxy server
0:33:16.140,0:33:23.140
which listens on port 3128, hopefully, or doesn't?
Oh, 8108, that's it.
0:33:47.360,0:33:49.060
Ok, so every
0:33:49.060,0:33:56.060
connection we want to make should actually be routed
through the Tor network
0:33:56.820,0:33:58.880
uhm, this is going to take a little bit,
0:33:58.880,0:34:01.950
Because all the route selection needs to be done
0:34:01.950,0:34:08.950
all the public crypto, there's also network latency
0:34:13.059,0:34:14.539
Once the connections are actually setup
0:34:14.539,0:34:17.789
it's pretty fast, not like this
0:34:17.789,0:34:21.159
and it's uh, really dependent upon uh,
0:34:21.159,0:34:21.419
which
0:34:21.419,0:34:23.059
kind of nodes you get
0:34:23.059,0:34:26.669
if you have a node that is running a modem then,
0:34:26.669,0:34:33.669
you'll have problem, it's really slow
0:34:36.099,0:34:42.989
Ok, while waiting
0:34:42.989,0:34:45.319
we can actually take a look
0:34:45.319,0:34:52.319
at how our hidden service is configured
0:34:59.699,0:35:03.369
There's some lines for the Tor config file
0:35:03.369,0:35:07.439
the routing services
0:35:07.439,0:35:14.219
Ok, so you can see here hidden services here and
hidden service port
0:35:14.219,0:35:19.369
as I said, the hidden service is identified by a
public key, and uh, if you
0:35:19.369,0:35:22.159
uncomment this stuff,
0:35:22.159,0:35:24.999
and uh,
0:35:24.999,0:35:26.619
we start Tor
0:35:26.619,0:35:28.249
quickly
0:35:28.249,0:35:31.690
generate a public key and put it into the start tree
0:35:31.690,0:35:38.690
and it will, uh, well it actually says to uh,
0:35:40.659,0:35:47.659
where this omni address earlier,
0:35:48.549,0:35:49.539
we'll just
0:35:49.539,0:35:56.539
route every connection through this address to this
local nodes line
0:36:02.119,0:36:07.199
This could be the case that uh,
0:36:07.199,0:36:08.640
that an exit node
0:36:08.640,0:36:11.599
doesn't uh,
0:36:11.599,0:36:18.599
allow DNS
0:36:19.779,0:36:22.900
Ok, this is typical that when you want to show stuff
it doesn't work
0:36:22.900,0:36:25.369
It worked earlier, so uh, it's not the network's fault
0:36:25.369,0:36:27.619
let's uh,
0:36:27.619,0:36:31.609
back to the hidden services
0:36:31.609,0:36:38.609
So we actually need to
0:36:39.230,0:36:46.230
change this
0:36:51.170,0:36:55.099
The default directory in FreeBSD is /var/db/tor
0:36:55.099,0:36:57.909
and uh,
0:36:57.909,0:37:03.249
and when we start Tor it will actually, uh
0:37:03.249,0:37:07.499
create the service directory
0:37:07.499,0:37:11.789
by itself. It's also a web server listening on port 80
on localhost
0:37:11.789,0:37:13.889
so we can
0:37:13.889,0:37:20.889
and hopefully will be able to see it later on
0:37:45.849,0:37:48.529
Okay, so let's see if
0:37:48.529,0:37:49.679
this stuff is already
0:37:49.679,0:37:56.679
actually created.
0:38:02.829,0:38:03.790
Ok, so you have
0:38:03.790,0:38:05.069
two parts in this directory
0:38:05.069,0:38:11.650
hostname and private key. Private key is uh,
self-explanatory
0:38:11.650,0:38:14.739
and the hostname is actually what you give to people
if you want to
0:38:14.739,0:38:21.739
to publish your service
0:38:33.319,0:38:36.039
This is actually less likely to work right now
0:38:36.039,0:38:40.059
because it takes some time for Tor to choose these
0:38:40.059,0:38:41.639
introduction points,
0:38:41.639,0:38:44.880
send all this stuff to directory services
0:38:44.880,0:38:47.369
It takes time for directory services to sync up
0:38:47.369,0:38:54.329
and actually distribute information to the clients
0:38:54.329,0:39:00.789
and when we want to access the service, we actually put
this address into the uh,
0:39:00.789,0:39:03.889
the address line, and uh,
0:39:03.889,0:39:05.069
Tor knows how to
0:39:05.069,0:39:12.069
deal with this uh, the Onion top-level domain, so uh
0:39:15.410,0:39:22.410
this usually actually works. Let's see what's going on here...
0:39:33.499,0:39:35.049
Well, like I said
0:39:35.049,0:39:37.529
this one will take a while and
0:39:37.529,0:39:40.450
what's going on with the other one? I can actually see
0:39:40.450,0:39:45.039
But uh,
0:39:45.039,0:39:47.850
usually you can just go to one of these server websites
0:39:47.850,0:39:50.209
that tell you your IP address, and
0:39:50.209,0:39:52.899
Google is a fair example
0:39:52.899,0:39:56.709
you can go to Google and Google will get you a
0:39:56.709,0:40:00.589
localized web page.
0:40:00.589,0:40:02.879
For example, when you are from Germany, and you go to
0:40:02.879,0:40:04.099
google.com, you get a German webpage
0:40:04.099,0:40:07.379
and if you're using Tor and you go to Google,
0:40:07.379,0:40:09.679
it depends
0:40:09.679,0:40:10.319
upon where your exit point is located
0:40:10.319,0:40:11.859
for example,
0:40:11.859,0:40:14.029
if it is in the Netherlands,
0:40:14.029,0:40:21.029
you get a Dutch Google, which is uh, pretty cool.
0:40:23.329,0:40:25.549
So uh,
0:40:25.549,0:40:27.419
I'll have to take a look later
0:40:27.419,0:40:28.829
while I'm working
0:40:28.829,0:40:35.829
So let's just, continue for a moment
0:40:38.569,0:40:41.009
Ok, to summarize, uh
0:40:41.009,0:40:44.799
Tor is actually useful if
0:40:44.799,0:40:51.799
you want to be hidden on the net. If it actually works.
Not in this case, uh
0:40:55.519,0:40:59.339
Tor is usually pretty cool to offer services from anywhere
0:40:59.339,0:41:00.410
so theoretically
0:41:00.410,0:41:02.509
it should work
0:41:02.509,0:41:03.549
that I
0:41:03.549,0:41:06.049
publish my hidden service around here
0:41:06.049,0:41:10.429
and anyone in the world that's connected to the Tor network
can actually access it
0:41:10.429,0:41:12.169
and uh
0:41:12.169,0:41:14.799
FreeBSD is a pretty cool platform for Tor
0:41:14.799,0:41:18.819
Because it has very nice
0:41:18.819,0:41:21.779
security features like jail
0:41:21.779,0:41:23.949
and if you want to run a Tor node
0:41:23.949,0:41:25.899
and uh,
0:41:25.899,0:41:27.949
tools like Tor are really needed
0:41:27.949,0:41:28.860
in our time
0:41:28.860,0:41:35.860
this isn't going
0:41:36.599,0:41:43.599
to get better any time soon; so uh, we better
create the tools now
0:41:45.779,0:41:52.779
to circumvent this
0:41:52.899,0:41:59.039
Take a quick look at the uh browser again
0:41:59.039,0:42:00.089
currently the uh,
0:42:00.089,0:42:02.660
connection set up failed
0:42:02.660,0:42:04.070
which I can't do anything about right now.
0:42:04.070,0:42:11.070
uh, which one?
0:42:23.089,0:42:25.629
Oh, that's all me
0:42:25.629,0:42:27.539
uhm
0:42:27.539,0:42:30.249
it depends upon
0:42:30.249,0:42:33.140
you can use any port you like
0:42:33.140,0:42:34.539
It depends on uh,
0:42:34.539,0:42:39.279
what port the nodes use. Nodes can use any port
0:42:39.279,0:42:42.259
for example, when I don't want to run nodes
0:42:42.259,0:42:44.109
I can put it on pause
0:42:44.109,0:42:45.679
port 80 if you want
0:42:45.679,0:42:47.470
so anyone who uh
0:42:47.470,0:42:49.219
who has uh
0:42:49.219,0:42:50.979
HTTP access can actually access my node
0:42:53.009,0:42:56.529
so uh
0:42:56.529,0:43:01.299
In theory uh
0:43:01.299,0:43:05.959
you can use any port you like.
0:43:05.959,0:43:12.009
So, this isn't going to work.
0:43:12.009,0:43:13.519
Maybe I'll just uh,
0:43:13.519,0:43:20.519
if anyone is interested, I'll just try again later
0:43:33.089,0:43:34.680
That's port 80
0:43:34.680,0:43:39.369
it's a you know, HTTP connection so,
0:43:39.369,0:43:42.359
So, are there any questions?
0:43:42.359,0:43:49.359
Yes?
0:44:06.140,0:44:08.689
Well, usually I use Opera, so
0:44:13.679,0:44:15.659
I didn't know
0:44:26.839,0:44:28.970
Yes, there are about 300 uh,
0:44:32.879,0:44:35.040
I think about
0:44:35.040,0:44:39.759
300 Tor servers around the world
0:44:39.759,0:44:43.349
No, it's uh correct
0:44:43.349,0:44:47.119
at the moment there are three directory servers
0:44:47.119,0:44:49.579
worldwide
0:44:49.579,0:44:51.630
you can recognize them by their public key
0:44:51.630,0:44:52.909
and their public keys are
0:44:52.909,0:44:56.119
hard coded into the source code at the moment
0:44:56.119,0:44:58.799
so, the uh
0:44:58.799,0:45:01.499
Tor developers actually run those directory servers
0:45:01.499,0:45:08.499
but this is really critical infrastructure
0:45:11.729,0:45:12.719
uhm
0:45:12.719,0:45:14.729
Well it's it's hard to say
0:45:14.729,0:45:16.219
Because the question was uh
0:45:16.219,0:45:21.799
Were there any estimates on uh,
0:45:21.799,0:45:26.489
net usage and other stuff
0:45:26.489,0:45:31.730
it's really hard to say because it's an anonymization
network so uh,
0:45:31.730,0:45:32.999
you can't say for sure, but there are estimates of
one hundred thousand users around the world
0:45:32.999,0:45:36.949
and uh, I'm not sure of the traffic.
0:45:36.949,0:45:39.219
I used to run a middleman node,
0:45:39.219,0:45:40.369
and in one month
0:45:40.369,0:45:42.699
it would make
0:45:42.699,0:45:43.849
it was on a one hundred megabits
0:45:43.849,0:45:45.359
or dedicated line,
0:45:45.359,0:45:47.249
and it made about one terabyte of traffic
0:45:47.249,0:45:49.459
so it's a lot of traffic
0:45:49.459,0:45:52.449
going on
0:45:52.449,0:45:56.259
and unfortunately also a lot of filesharing systems
0:45:56.259,0:45:59.739
which it doesn't really make sense because they're slow
0:45:59.739,0:46:00.570
So uhm,
0:46:00.570,0:46:01.609
Tor is really cool
0:46:01.609,0:46:03.359
for web browsing and stuff
0:46:03.359,0:46:10.359
but if you really want to move a lot of data it's
not a good tool
0:46:10.759,0:46:11.479
Ah, any other questions? Doesn't seem to be the case. Ok!