Modern digital currency mostly seem to revolve around a construct called a blockchain, which – by design – is a (mostly!) append-only distributed database that is intended to keeps all the transactions for all time. Blockchains use strong cryptographic methods to ensure its integrity and fidelity, and is typically decentralized, meaning that the entire chain is distributed in close-to-real-time fashion over the Internet to all computers that are using […]
how many factors, anyway?
I’ve been using Google’s 2 factor authentication for awhile now, it’s simple to use and seems effective (and is probalby the most commonly used 2F on earth.) But how many factors is it, really? But perhaps I could try to distill this even a bit more, and go radical… is the 2nd factor really necessary or just a productivity hit/distraction? Once per month or so it dutifully asks me […]
trivial command line…..
Was just noticing the shell option in ipmitool.. wondered if you could echo a set of commands to it via stdin, and sure enough… the final bit is sending it a ctrl^D via \003 and echo -e. This sends a chassis power status as well as a sol, channel, and mc info to BMC – $ echo -e "chassis power status\nsol info\nchannel info 0\nmc info\n\004" | ipmitool -I lanplus […]
The free certs from https://letsencrypt.org/ do indeed work as described. I wanted to check them out for some public facing services I wanted to run. To get the certificate you run a program on a host that DNS resolves to the cert you want to get – so if “foo.example.com” resolves to 10.6.6.6, you need to install the cert generation program on 10.6.6.6, and have either 80 or 443 free (I […]
really, really, really nuke iptables
I think this is the way to really clear out all the stuff in iptables, the arcane packet filtering thing for Linux. At least… I think. My take on it, at least. For somewhat modern Linuxes at the time of this writing, IPv4 only. Basic method: loop over all the types of tables, flushing… then loop over all the builtin tables for the various types, reset the policies… then […]