After meeting Niels Möller at FOSDEM and learning about his Ed25519 implementation in GNU Nettle, I started working on a simple-to-implement description of Ed25519. The goal is to help implementers of various IETF (and non-IETF) protocols add support for Ed25519. As many are aware, OpenSSH and GnuPG has support for Ed25519 in recent versions, and OpenBSD since the v5.5 May 2014 release are signed with Ed25519. The paper describing EdDSA and Ed25519 is not aimed towards implementers, and does not include test vectors. I felt there were room for improvement to get wider and more accepted adoption.
Our work is published in the IETF as draft-josefsson-eddsa-ed25519 and we are soliciting feedback from implementers and others. Please help us iron out the mistakes in the document, and point out what is missing. For example, what could be done to help implementers avoid side-channel leakage? I don’t think the draft is the place for optimized and side-channel free implementations, and it is also not the place for a comprehensive tutorial on side-channel free programming. But maybe there is a middle ground where we can say something more than what we can do today. Ideas welcome!
I am happy to announce a project that I have been working quietly on for about a year: the OATH Toolkit. OATH stands for Open AuTHentication and is an organization that specify standards around authentication. That is a pretty broad focus, but practically it has translated into work on specifying standards around deploying and using electronic token based user authentication such as the YubiKey.
OATH’s most visible specification has been the HOTP algorithm which is a way to generate event-based one-time passwords from a shared secret using HMAC-SHA1. HOTP has been published through the IETF as RFC 4226. Built on top of HOTP is the time-based variant called TOTP, which requires a clock in the token. OATH do some other work too, like specifying a data format for transferring the token configuration data (e.g., serial number and shared secret) called PSKC. Continue reading →
The RFC Editor has announced a new document, RFC 6070, with test vectors for PKCS5 PBKDF2. The document grow out of my implementation of SCRAM for GNU SASL. During interop testing, more than one other implementation turned out to have mistakes in the PBKDF2 implementation. It didn’t help that there weren’t any stable test vectors for PBKDF2, so that we could do black-box testing of our PBKDF2 implementations against well-known and stable test vectors. Debugging this was time consuming. The document addresses this problem.
I have worked in the IETF on the specification for the next generation GSSAPI-to-SASL bridge called GS2 (see my status page for background) for a couple of years now. The specification is (finally!) in the RFC editor’s queue, and is supposed to be stable and final although we are still tuning some details. The next step is to implement the protocol and do interop testing. A couple of months of implementation and testing work culminated in tonight’s release of GNU SASL 1.5.0 (see announcement here). Or should I say that the work can now begin… Continue reading →