cryptsetup allows to create keyslot with non existing hash applied to AF splitter (LUKS2, argon2 pbkdf only)
[root@machine ~]# cryptsetup luksFormat --type luks2 --hash some-nonsense /dev/sdx -q -v
Enter passphrase for /dev/sdx:
Key slot 0 created.
Command successful.
[root@machine ~]# cryptsetup open /dev/sdx -v --test-passphrase
Enter passphrase for /dev/sdx:
Command failed with code -1 (wrong or missing parameters).
Command creates unusable LUKS2 container. It may happen also if you pass non-existing hash to luksAddKey operation on valid LUKS2 container. The keyslot gets created, but it can't be unlocked.
Edited by Ondrej Kozina