We used to do validation using lists of mandatory feature flags.
With the introduction of XChaCha20Poly1305, this became too
simplistic, as it uses a different IV length, hence disabling
GCMIV128.
Add a dedicated function, Validate(), with open-coded validation
logic.
The validation and creation logic also gets XChaCha20Poly1305
support, and gocryptfs -init -xchacha now writes the flag into
gocryptfs.conf.
Our git version is v2+ for some time now, but go.mod
still declared v1. Hopefully making both match makes
https://pkg.go.dev/github.com/rfjakob/gocryptfs/v2 work.
All the import paths have been fixed like this:
find . -name \*.go | xargs sed -i s%github.com/rfjakob/gocryptfs/%github.com/rfjakob/gocryptfs/v2/%
TrezorPayload stores 32 random bytes used for unlocking
the master key using a Trezor security module. The randomness makes sure
that a unique unlock value is used for each gocryptfs filesystem.
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.
As we have dropped Go 1.4 compatibility already, and will add
a new feature flag for gocryptfs v1.3 anyway, this is a good
time to enable Raw64 as well.
tlog is used heavily everywhere and deserves a shorter name.
Renamed using sed magic, without any manual rework:
find * -type f -exec sed -i 's/toggledlog/tlog/g' {} +
This should make things saner and more extensible. It prepares
the infrastructure for "required feature flags" that will be used
to deprecate old gocryptfs version.
This field is added for the convenience of users and
may help them to identify which gocryptfs version
they need to mount a filesystem.
The same information is essentially contained in FeatureFlags,
but this is more difficult to decode for humans.
It is completely ignored programmatically (also by older gocryptfs
versions).
