There are more POODLEs in the forest

In December it was announced that several TLS server implementations were affected by a problem similar to an SSL v3 issue called POODLE disclosed by Google researchers in October. This attack worked by modifying the padding bytes of the encrypted SSL/TLS records that are used to make the records into even multiples of 8 or 16 byte blocks of data, checking how the server responded, and used this to deduce the plain text of the transmitted data, one byte at a time, with just a few tries.

Several major vendors were affected by the TLS variant of the POODLE issue, and released patches. Continue reading «There are more POODLEs in the forest»

The POODLE has friends

In October last year, researchers from Google published details about an attack on SSL v3, called POODLE. This attack worked by modifying the padding bytes of the encrypted SSL records that are used to make the records into even multiples of 8 or 16 byte blocks of data, as used by 3DES and AES encryption in the «CBC» mode, checking how the server responded, and used this to deduce the plain text of the transmitted data, one byte at a time, with just a few tries. Continue reading «The POODLE has friends»

Usikker registrering av persondata i mange nettbutikker

[Apologies to my English language readers, as this article mainly concerns encryption in Norwegian online shopping sites, I decided to write it in Norwegian]

Jeg har ved at par tidligere anledninger undersøkt bruken av kryptering av norske nettbutikker, sist i 2013. Konklusjonen begge ganger har vært at kryptering er lite brukt.

I løpet av januar gjennomførte jeg en ny undersøkelse av kryptering i norske nettbutikker. I tillegg til 59 butikker jeg hadde undersøkt tidligere, inkluderte jeg denne gangen 184 nye nettbutikker fra Posten.no‘s liste over nettbutikker, totalt 243 butikker.  Continue reading «Usikker registrering av persondata i mange nettbutikker»

Not out of the woods yet: There are more POODLEs

As I wrote in my previous article about this, in October a group of Google security researchers had discovered a problem, called POODLE, in SSL v3 that in combination with another issue, browsers’ automatic fallback to older TLS and SSL versions, allowed an attacker to quickly break the encryption of sensitive content, like cookies.

The main mitigating methods for this problem are disabling SSL v3 support, both server side (now down to 66.2%, but slowing down) and in the client, and to limit the automatic fallback, either by not falling back to SSL v3 (which is now implemented by several browsers), or by a new method called TLS_FALLBACK_SCSV (introduced by Google Chrome and others). Continue reading «Not out of the woods yet: There are more POODLEs»

Attack of the POODLEs

Three weeks ago a group of researchers from Google announced an attack against the SSL v3 protocol (the ancestor of the TLS 1.x protocol) called POODLE (a stylish abbreviation of «Padding Oracle On Downgraded Legacy Encryption»). This attack is similar to the BEAST attack that was revealed a few years ago, and one of the researchers that found the POODLE attack was part of the team that found BEAST.

POODLE is able to quickly discover the content of a HTTPS request, such as a session cookie, but only if the connection is using the SSL v3 protocol, a version of SSL/TLS that became obsolete with the introduction of TLS 1.0 in 1999. As almost all (>99%) secure web servers now support at least TLS 1.0 (which is not vulnerable to the attack, provided the server is correctly implemented), it might sound like this attack is not very useful. Unfortunately, that is not so. Continue reading «Attack of the POODLEs»

What is tls-testing.tlsprober.net?

Executive summary: The TLS Prober is a tool that gathers information and statistics about the state of the SSL/TLS protocol security features and vulnerabilities across the internet. It does nothing that will harm your server.

The TLS Prober is a tool I developed while I worked I worked at Opera Software, originally to track the progress of the TLS Renego problem, and which I was allowed to take with me when I left Opera in early 2013. It is primarily used to scan a set of 23 million hostnames, most of the names derived from Alexa top million domain names, resulting in tests of about 500000 unique servers, for their support of SSL and TLS features, as well as checking for various interoperability issues and vulnerabilities.

Similar tools are also in use by others, such as the Qualys SSL Labs prober. Continue reading «What is tls-testing.tlsprober.net?»

Vivaldi.net now showing EV-green in browsers

Friday evening (20 December) those who keep an eye on the browser UI would have observed a small but significant change take effect at Vivaldi.net: The browser turned on the Extended Validation «Green Bar» for us, indicating that the identity of our website was now better assured than it has been, though the encryption is just as good as before.

Previously, while we were developing the site and during the first days of it being live, we used a Domain Validated SSL/TLS certificate for our sites that indicated that we had control over the domain, but not who we are. This is a useful level of web site identity verification for smaller sites that only need to present information securely and without any major collection of personal information. 

For users of a web site that collects or manages personal and payment information, it is not just important to know that the people managing the web site are in control of the domain. It is even more important to know, or be able find out, who they are, legally speaking, in case there is a problem.

This need for verifiable identity information was why a group of Certificate Authorities, such as Verisign and Entrust, and Browsers, such as Microsoft, Mozilla and Opera (including yours truly), gathered to found the CA/Browser Forum so that we could define what eventually became the Extended Validation (EV) Guidelines for CAs, and the associated «Green Bar» in browsers.

When Jon decided to start the Vivaldi.net social web site project, one of my suggestions was to have an encrypted site. Given recent revelations (e.g., NSA) it is now, or should be, unthinkable to have a social web site that is unencrypted. While many sites have been using a hybrid approach where the login, account management, and sometimes authoring, is encrypted, there are just too many ways to sniff information that way, so the whole site needs to be encrypted. Another of my suggestions was to use EV certificates on the sites, to provide better identity information and assurances to our users.

While I would have wished to have unveiled Vivaldi.net on Wednesday with an EV certificate, the process of obtaining one was intentionally designed to include a lot of paperwork that has to be completed before the certificate can be issued, and that paperwork was not completed by our CA, GlobalSign, until early evening Friday.

So, go ahead and enjoy Vivaldi.net, assured that it is Jon’s company, Vivaldi Technologies AS, that is operating it.