replace NTP about portalofpi

[grugq]

tlsdate is available from the AUR, which is good. Unfortunately, it requires building. Which is less good. That means we'll have to pull in the whole of build-essential to get it up and running. I'm ok with this, provided there is a way to remove the whole of build-essential once we're done.

[grugq]

Ok, so the other issue with tlsdate is that it won't work unless NTP is already running. When the RPi boots up, the date+time is set to the epoch (0x0000000000) which has to be corrected by NTP before Tor will negotiate a circuit. The problem with tlsdate is that it fails if the time delta between the localhost and the remote server exceeds some value. Regardless of what that value is, it has been 40++ years since the epoch, that is a huge delta. I'm not sure what tlsdate buys us that NTP doesn't, and NTP is standard, mainline default, doesn't require a compile, etc.

Right now, I'm gonna say tlsdate is not useful enough to warrant dealing with these issues, particularly if one of them is "we need to keep NTP". Closing it out until someone wants to deal with it.