Do we need elliptic curve point compression?
GnuTLS has recently added support for elliptic curves (ECDSA and Elliptic curve Diffie-Hellman). Elliptic curves are an improvement on public key technologies, mostly in efficiency because they require...
View ArticleThe need for SSH-like authentication in TLS
After the Diginotar CA compromise it is apparent that verifying web sites using only a trusted certificate authority (CA) is not sufficient. Currently a web site's certificate is verified against the...
View ArticleGoogle summer of code
This year GnuTLS participates in the Google summer of code under the GNU project umbrella. If you are a student willing to spend this summer coding, check our ideas.
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TLS in embedded systems
In some embedded systems space may often be a serious constraint. However, there are many such systems that contain several megabytes of flash either as an SD memory card, or as raw NAND, having no...
View ArticleA flaw in the smart card Kerberos (PKINIT) protocol
Reading security protocols is not always fun nor easy. Protocols like public key Kerberos are hard to read because they just define the packet format and expect the reader to assume a correct message...
View ArticleUsing the Trusted Platform Module to protect your keys
There was a big hype when the Trusted Platform Module (TPM) was introduced into computers. Briefly it is a co-processor in your PC that allows it to perform calculations independently of the main...
View ArticleSome thoughts on the DANE protocol
A while ago I was writing on why we need an alternative authentication method in TLS. Then I described the SSH-style authentication and how it was implemented it GnuTLS. Another approach is the DANE...
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Time is money (in CBC ciphersuites)
While protocols are not always nicely written, deviating from them has a big disadvantage. You cannot blame someone else if there is a problem. It has a small advantage though, you avoid monoculture...
View ArticleThe perils of LGPLv3
LGPLv3 is the latest version of the GNU Lesser General Public License. It follows the successful LGPLv2.1 license, and was released by Free Software Foundation as a counterpart to its GNU General...
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Salsa20 and UMAC in TLS
Lately while I was implementing and deploying an SSL VPN server, I realized that even for a peer-to-peer connections the resources taken for encryption on the two ARM systems I used were quite...
View ArticleInside an SSL VPN protocol
Some time ago when trying to provide a way to interconnect the routers of the company I was working on, I attempted to evaluate the various secure VPN solutions available as free software. As I was...
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software has bugs... now what?
The recent bugs uncovered in TLS/SSL implementations, were received in the blogo-sphere with a quest for the perfectly secure implementations, that have no bugs. That is the modern quest for perpetual...
View ArticleWhat about POODLE?
Yesterday POODLE was announced, a fancy named new attack on the SSL 3.0 protocol, which relies on applications using a non-standard fallback mechanism, typically found in browsers. The attack takes...
View ArticleA quick overview of GnuTLS development in 2014
2014 was a very interesting year in the development of GnuTLS. On the development side, this year we have incorporated patches with fixes or enhanced functionality from more than 25 people according to...
View ArticleSoftware Isolation in Linux
Starting from the assumption that software will always have bugs, we need a way to isolate and neutralize the effects of the bugs. One approach is by isolating components of the software such that a...
View ArticleAn overview of GnuTLS 3.4.x
This April GnuTLS 3.4.0 was released, as our stable-next branch, i.e., the branch to replace the current stable branch of GnuTLS (which as of today is the 3.3.x branch). During that time, we also...
View ArticleWhy do we need SSL VPNs today?
One question that has been bothering me for quite a while, is why do we need SSL VPNs? There is an IETF standardized VPN type, IPSec, and given that, why do SSL VPNs still get deployed? Why not just...
View ArticleAn overview of the new features in GnuTLS 3.5.0
Few minutes ago I've released GnuTLS 3.5.0. This is the stable-next branch of GnuTLS which will replace the stable GnuTLS 3.4.x branch within a year. It is fully backwards compatible and comes with...
View ArticleRestricting the scope of CA certificates
The granting of an intermediate CA certificate to a surveillance firm generated quite some fuss. Setting theories aside, the main reason behind that outcry, is the fact that any intermediate CA...
View ArticleA brief look at the Linux-kernel random generator interfaces
Most modern operating systems provide a cryptographic pseudo-random number generator (CPRNG), as part of their OS kernel, intended to be used by applications involving cryptographic operations. Linux...
View ArticleUsing the Nitrokey HSM with GnuTLS applications
The Nitrokey HSM is an open hardware security module, in the form of a smart card token, which is used to isolate a server's private key from the application. That is, if you have an HTTPS server, such...
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Improving by simplifying the GnuTLS PRNG
One of the most unwanted baggages for crypto implementations written prior to this decade is the (pseudo-)random generator, or simply PRNG. Speaking for GnuTLS, the random generator was written at a...
View ArticleThe mess with internationalized domain names
While internationalized domain names (DNS names) are not common in the English speaking world, they exist and their use was standardized by IETF's IDNA standards. I first found out the existence of...
View ArticleAn overview of GnuTLS 3.6.0
The new 3.6.0 GnuTLS release contains several new features, back-end changes and clean ups. This is a release which re-spins the so-called 'stable-next' branch, meaning that once considered stable...
View ArticleGnuTLS and TLS 1.3
GnuTLS already contains support for the latest TLS 1.3 draft (draft-ietf-tls-tls13-26) on its master git branch. TLS 1.3 will be included and enabled by default in the upcoming 3.6.3 release, once the...
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