dracut/modules.d/98ecryptfs

# Directions for creating the encrypted key that will be used to mount an
# eCryptfs filesystem

# Create the eCryptfs key (encrypted key type)
#
# The encrypted key type supports two formats: the 'default' format allows
# to generate a random symmetric key of the length specified, the 'ecryptfs'
# format generates an authentication token for the eCryptfs filesystem,
# which contains a randomly generated key. Two requirements for the latter
# format is that the key description must contain exactly 16 hexadecimal
# characters and that the encrypted key length must be equal to 64.
$ keyctl add encrypted 1000100010001000 "new ecryptfs trusted:kmk-trusted 64" @u
782117972

# Save the encrypted key
$ su -c 'keyctl pipe `keyctl search @u encrypted 1000100010001000` > /etc/keys/ecryptfs-trusted.blob'

# The eCryptfs key path name can be set in one of the following ways (specified in
# the order in which the variable is overwritten):

1) use the default value:
--------------------------------------------------------------------------
ECRYPTFSKEY="/etc/keys/ecryptfs-trusted.blob"
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2) create the configuration file '/etc/sysconfig/ecryptfs' and set the ECRYPTFSKEY
variable;

3) specify the eCryptfs key path name in the 'ecryptfskey=' parameter of the kernel command
line.

# The configuration file '/etc/sysconfig/ecryptfs' is also used to specify
# more options for mounting the eCryptfs filesystem:

ECRYPTFSSRCDIR: existent directory in the lower root filesystem;
ECRYPTFSDSTDIR: mount point directory for the eCryptfs filesystem (the directory must be
                created in the root filesystem before rebooting the platform);
ECRYPTFS_EXTRA_MOUNT_OPTS: extra mount options for the eCryptfs filesystem (the 'ecryptfs_sig'
                           option is automatically added by the dracut script).

# Example of the configuration file:
----------- '/etc/sysconfig/ecryptfs' (with default values) -----------
ECRYPTFS_KEY="/etc/keys/ecryptfs-trusted.blob"
ECRYPTFSSRCDIR="/secret"
ECRYPTFSDSTDIR="${ECRYPTFSSRCDIR}"
ECRYPTFS_EXTRA_MOUNT_OPTS=""
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# If the variable ECRYPTFSDSTDIR is not specified in the configuration file,
# its value will be equal to that of ECRYPTFSSRCDIR.