Commit f3c777d5ea added the `-devrandom` option:
commit f3c777d5ea
Author: @slackner
Date: Sun Nov 19 13:30:04 2017 +0100
main: Add '-devrandom' commandline option
Allows to use /dev/random for generating the master key instead of the
default Go implementation. When the kernel random generator has been
properly initialized both are considered equally secure, however:
* Versions of Go prior to 1.9 just fall back to /dev/urandom if the
getrandom() syscall would be blocking (Go Bug #19274)
* Kernel versions prior to 3.17 do not support getrandom(), and there
is no check if the random generator has been properly initialized
before reading from /dev/urandom
This is especially useful for embedded hardware with low-entroy. Please
note that generation of the master key might block indefinitely if the
kernel cannot harvest enough entropy.
We now require Go v1.13 and Kernel versions should have also moved on.
Make the flag a no-op.
https://github.com/rfjakob/gocryptfs/issues/596