I'm a big fan of hardware tokens for access. The three basic technologies where you have public key crypto are SSH, GPG and SSL. Here I will show how to use a Yubikey NEO to protect GPG and SSH keys so that they cannot be stolen or copied. (well, they can be physically stolen, of course).
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Last time I was at a hacker conference I for obvious reasons didn't want to connect to the local network. It's not just a matter of setting up some simple firewall rules, since the people around you are people who have and are inventing new and unusual attacks. Examples of this would be rogue IPv6 RA and NDs, and people who have actually generated their own signed root CAs. There's also the risk (or certainty) of having all your unencrypted traffic sniffed and altered.
For next time I've prepared a SheevaPlug computer I had laying around. I updated it to a modern Debian installation, added a USB network card, and set it up to provide always-on VPN. This could also be done using a raspberry pi, but I don't have one.
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As you remember from long ago hashes are O(1) best case, but can be O(n)
if you get hash collisions. And if you're adding n new entries
that means O(n^2).
I thought I'd take a look at the hash_set/hash_map GNU C++ extension.
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As you can plainly see from this graph, my TPM chip can do approximately 1.4 SSL handshakes per second. A handshake takes about 0.7 seconds of TPM time, so when two clients are connecting the average connect time is 1.4 seconds. This means probably not useful on server side, but should be good for some client side applications.
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This is a short howto on setting up TPM-backed SSL. This means that the secret key belonging to an SSL cert is protected by the TPM and cannot be copied off of the machine or otherwise inspected.
Meaning even if you get hacked the attackers cannot impersonate you, if you manage to kick them off or just shut down the server. The secret key is safe. It has never been outside the TPM and never will be.
This can be used for both client and server certs.
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When connecting to a possibly hostile network I want to tunnel all traffic from my browser to some proxy I have set up on the Internet.
The obvious way to do this is with a proxy. The problem with that is that the traffic from the browser to the proxy is not encrypted. Even when you browse to secure SSL sites some traffic is being sent in the clear, such as the host name. That's not so bad, but I want to hide my HTTP traffic too.
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Yubico and their products are awesome.
That pretty much sums up this blog post but I'm going to go on anyway. If you're thinking of introducing two-factor authentication to your company, or you're using something that's fundamentally broken (like RSA SecureID) you simply must at least take Yubikeys into consideration.
Read the rest of this entry »The documentation for OpenSSH certificates (introduced in OpenSSH 5.4) are, shall we say, a bit lacking. So I'm writing down the essentials of what they are and how to use them.
In other words if your .pub file doesn't end in -cert.pub and you haven't used ssh-keygen -s, then you aren't using certificates.
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I've started writing a replacement for SSH.
Why? Because SSH has some drawbacks that sometimes annoy me. I also wanted an authentication scheme that's more similar to SSL/TLS than what SSH does.
With tlssh you don't specify username or password, you simply connect to the server using a client-side certificate to log in as the user specified in the certificate. No interaction until you reach the shell prompt on the server.
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Yes clipboard, not keyboard. I've made a clipboard sniffer for X called ClipSniff.
It periodically saves whatever is in the clipboard (both the "PRIMARY" and the "CLIPBOARD") into a sqlite database.
git clone http://github.com/ThomasHabets/clipsniff.gitRead the rest of this entry »
