Feedback on Lab 22.2 Encrypted Swap
I just wanted to point out that at step 5 (a) it gives an example config for /etc/crypttab. Specifically:
swapcrypt /dev/sda11 /dev/urandom swap,cipher=aes-cbc-essiv:sha256,size=256
Because i read the man pages as extensively as i can, i noticed that:
1) From man crypttab "...note however that LUKS requires a persistent key and therefore does not support random data keys"
2) From man cryptsetup "The current default in the distributed sources is "aes-cbc-essiv:sha256" for plain dm-crypt and "aes-xts-plain64" for LUKS."
So it seems that both /dev/urandom and cipher don't (or won't) work. I know that it mentions that it is an example but it could cause trouble to some.
i didn't tyr to replicate the above to see if it will work at all, since i had already done twice the 22.1 lab, with 2 virtual drives (one with boot mount, and one with not), and i had to troubleshoot, since i did a mistake of "sudo vim crypttab" instead of "sudo vim /etc/crypttab" (you guess what happened, system didn't boot, and ended up in emergency mode. Thankfully i found the error in the first couple of minutes).
The above is from the last update March 27th, 2020.