Explained: Kerberos

It is 9 a.m. on a Monday. You type your password once to log into your work laptop. Then the day just happens: the shared drive opens, the intranet loads, Outlook connects, you print to the machine down the hall, you SSH into a build server. Not one of those systems asked for your password. Somehow, they all know who you are. That quiet magic is, in most corporate networks, Kerberos . It has been running underneath Windows Active Directory since 2… Read More

Explained: SASL

You're wiring up a new mail server. You reach the part where clients log in, and you open the SMTP docs to find not one login method but a menu of them: PLAIN , LOGIN , CRAM-MD5 , SCRAM-SHA-256 , OAUTHBEARER , GSSAPI . Then you open the IMAP docs for the same server, and it's the same menu again. Then LDAP. Then XMPP. The same names, the same handshakes, described separately in four different specifications. That repetition is exactly the probl… Read More