Make TransactionID generation non-blocking about dhcp HOT 5 CLOSED

It's necessary to use crypto/rand as a way to prevent "MITM" (without the middle). I.e. if you're a malicious actor in your network, and you don't get to see DHCP requests, but you can arbitrarily send responses out... wouldn't it be nice if you could predict the transaction ID?

from dhcp.

Good point. I'll rather make the generation not to block forever, and fail (configurably) if it's taking too many rounds or too much time

from dhcp.

See u-root/u-root#1129

from dhcp.

see also golang/go@1961d8d

in Go 1.12, crypto/rand will print a warning after 60 seconds of blocking.

from dhcp.

in Go 1.12, crypto/rand will print a warning after 60 seconds of blocking.

That's how we got it quickly this time :)

from dhcp.