.Finer control over MACs in SSH with `crypto-policies`
You can now set additional options for message authentication codes (MACs) for the SSH protocol in the system-wide cryptographic policies (`crypto-policies`). With this update, the `crypto-policies` option `ssh_etm` has been converted into a tri-state `
etm@SSH` option. The previous `ssh_etm` option has been deprecated.
You can now set `ssh_etm` to one of the following values:
`ANY`:: Allows both `encrypt-then-mac` and `encrypt-and-mac` MACs.
`DISABLE_ETM`:: Disallows `encrypt-then-mac` MACs.
`DISABLE_NON_ETM`:: Disallows MACs that do not use `encrypt-then-mac`.
Note that ciphers that use implicit MACs are always allowed because they use authenticated encryption.