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When you put your credit card into a website what happens to it?  The goal of this article is to explore some of the possible answers to that question.

With all the changes that are happening in the payment card industry these days, I’ve been thinking about security around it. EMV/Chip and PIN is coming and there are weird things happening around NFC/ApplePay/Google Wallet/Tap to Pay.  There have also been a lot of breaches in the last year, that are really helping expose the weaknesses in how this data is stored and transmitted.  This post is really more a thought experiment about how you store hashed information “securely”.

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Have you ever wondered what would happen if you tried to connect to a website that was serving a certificate chain way longer than normal?  I know, me too.  Often times security research is about thinking outside the box, and this is just one of those times.  Plus we might learn a few things along the way.

I’m new here.  What is a certificate chain?

When you connect to a secure website, your browser uses a TLS certificate to verify the authenticity of the connection and to help set ensign tonyup the encryption of the connection.  The way that you know that the certificate is valid is either because you have seen it before and saved it as a remembered certificate(this is common in a self-signed certificate situation or with SSH), in most cases someone else that you trust “signs” the website’s certificate.  Allow me to use Star Trek The Next Generation characters(source) to illustrate how this works.  If you meet Ensign Tony at Ten Forward, the next time that you meet him you will know who he is based on what he looks or sounds like.  This is how self-signed certificates work.
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A while ago Google announced its project zero, which is a team of security researchers, whose goal is to find bugs in software, so that you, dear user, can use the web and technology securely.  They were very up front about how the team would work.  They would report bugs and vulnerabilities that they have found to the companies or people responsible for maintaining the software.  Google would give the developers 90 days to fix the bug and then let the world know about it.

It turns out that Microsoft Windows has a few bugs in it(who knew?).  On more than one occasion Google discovered vulnerabilities in Windows.  On two of these occasions Microsoft was notified of these vulnerabilities and was “unable” to patch the vulnerability before the 90 days elapsed.  I have read many articles about this and I feel like they are almost all completely out to lunch.  I won’t even link to them because I feel they are so poorly informed on this topic.
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What is Firesheep?

You may remember about 4 years ago Eric Butler released a Firefox extension that did something very clever.  It hooked into a packet capture library and could capture cookies that weren’t sent over SSL, at an open Wi-Fi access point.   That extension was Firesheep.  The press grabbed onto this story as it made “hacking” into someone’s Facebook account something almost anyone could do.  At the time, many sites would shuttle you securely over https:// for the login and then give you an authentication cookie that was served insecurely over http://.  This authentication cookie is the thing that proves you are who you say you are so if a bad guy got access to this cookie, they could easily impersonate you on that site.

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I was thinking about this question the other day.  It SEEMS obvious…  I relialized that it relates to one of my favourite misconceptions about https or SSL/TLS.  Often people get too focused on the encryption aspect of SSL/TLS and not the authenticity and verification properties of it.  When Google first announced that Google search was going to be over “https” a few years ago I, like a lot of people, assumed that it was because it was to make your search results private.


Google’s support page, regarding SSL Search, quite correctly points out:

SSL doesn’t always protect:

  • The fact that you visited
  • The search terms that you typed


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VPN Introduction

I have been doing some work with VPNs lately, having set up a PPTP(Point to Point Tunneling Protocol) VPN for some Android network analysis that I have been doing lately.  It is easy to set up on a server and a mobile device, but PPTP generally isn’t secure unless you are using (P)EAP.  I wanted to try out something that overlaps with something that I’m pretty knowledgeable about, TLS/SSL, with something I have never had to actually set up, an SSL VPN.  Most people who use a VPN to connect into work use an SSL VPN.  Probably either from someone like Cisco or Juniper.  They are pretty easy to set up on the router side of things, and relatively easy for client device to get set up.  Other advantages are that they can be run over port 443, so they won’t be blocked by most firewalls, and that they use the verification properties inherent to TLS/SSL rather than some sort of challenge-response handshake.  Using TLS/SSL allows them to also be flexible about key sizes and cipher suites used and upgrade them as the future requires.
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I’m very excited to announce the launch of AM I SHA-1 – the SHA-1 Checkinator. This is a site that I have been working on for a few months off and on. Ever since Google announced that they were going to sunset support for SHA-1 support in Chrome, I felt that it would be cool to have an easy site to check your SSL/TLS certs. It isn’t difficult to check your certificates yourself, but not everyone is able to analyze their own certificates and understand the context under which they need to act to upgrade their certificates before the end of 2016. The tool/site I made takes a URL and downloads and parses the certificates for a site, and then helps you determine what action if any is required on your certificates. I realize that there are several tools out there that check for this already, but most of these are bundled into more extensive tests and the tests often take a long time to run. My goal with this site, was to be lean and quick so I focused on just checking for the presence of SHA-1 signatures in chain and leaf certificates. Plus it was a great learning experience.
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