doc: Fix acronym "FEKEK" in ecryptfs

"FEFEK" was incorrectly used as acronym for "File Encryption Key
Encryption Key". This replaces all occurences with "FEKEK".

Signed-off-by: Felix Eckhofer <felix@eckhofer.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Felix Eckhofer 2018-09-17 11:34:48 +02:00 committed by Jonathan Corbet
parent c03e2fa753
commit ff34876377

View File

@ -5,10 +5,10 @@ Encrypted keys for the eCryptfs filesystem
ECryptfs is a stacked filesystem which transparently encrypts and decrypts each
file using a randomly generated File Encryption Key (FEK).
Each FEK is in turn encrypted with a File Encryption Key Encryption Key (FEFEK)
Each FEK is in turn encrypted with a File Encryption Key Encryption Key (FEKEK)
either in kernel space or in user space with a daemon called 'ecryptfsd'. In
the former case the operation is performed directly by the kernel CryptoAPI
using a key, the FEFEK, derived from a user prompted passphrase; in the latter
using a key, the FEKEK, derived from a user prompted passphrase; in the latter
the FEK is encrypted by 'ecryptfsd' with the help of external libraries in order
to support other mechanisms like public key cryptography, PKCS#11 and TPM based
operations.
@ -22,12 +22,12 @@ by the userspace utility 'mount.ecryptfs' shipped with the package
The 'encrypted' key type has been extended with the introduction of the new
format 'ecryptfs' in order to be used in conjunction with the eCryptfs
filesystem. Encrypted keys of the newly introduced format store an
authentication token in its payload with a FEFEK randomly generated by the
authentication token in its payload with a FEKEK randomly generated by the
kernel and protected by the parent master key.
In order to avoid known-plaintext attacks, the datablob obtained through
commands 'keyctl print' or 'keyctl pipe' does not contain the overall
authentication token, which content is well known, but only the FEFEK in
authentication token, which content is well known, but only the FEKEK in
encrypted form.
The eCryptfs filesystem may really benefit from using encrypted keys in that the