Skip to content

{ Category Archives } cryptography

Google Authenticator One-time Password Algorithm in Javascript

I’ve recently setup 2-factor authentication on my Google account.  The new 2nd factor or “thing you have” is a smartphone application which generates 6 digit one-time passwords. I was a bit surprised when I stumbled on this article Two Factor SSH with Google Authenticator. Turns out the algorithm used to generate the OTPs is an […]

Subject Alternative Names for SSL

Last time I blogged about SSL and host-headers I was convinced it is only possible to host multiple SSL sites on one IP address when using a wildcard certifcate. I think I was right at the time, and now comes along Unified Communications UC SSL Certificates (aka Subject Alternative Name). Same issue as before: host-headers […]

Should you trust lastpass.com?

lastpass.com looks like a handy online service for storing all your website passwords. Browser extensions are available to make the whole process easier. If you use the web from several PCs it does sound nice to have all your passwords available and synced between your PCs. First thought was wether I should hand over my […]

Sending a DKIM Signed Email from C#

First off this code is intended to be instructional only! Yes it is possible to send a DKIM email from .net’s SmtpClient. But there are a few hacks/warnings to go with the following code. I’m pretty sure DKIM is designed for signatures to be added by the STMP server. All the emails I’ve seen with […]