When running Lustre client on RHEL8.2, Kerberos authentication can fail with the following message:

LustreError: 323835:0:(gss_crypto.c:68:gss_keyblock_init()) failed to allocate tfm: cbc(aes), mode 0: rc = -2

Problem stems from the fact that in RHEL8.2 (and Ubuntu 18.04 and possibly newer distros, as it depends on the kernel), the cbc(aes) crypto engine's type is now skcipher. In previous distros like RHEL7, type is blkcipher. This type has an impact on the primitive to call from Lustre in order to allocate an associated cipher handle.