e4crypt(8) — Linux manual page


E4CRYPT(8)               System Manager's Manual              E4CRYPT(8)

NAME         top

       e4crypt - ext4 file system encryption utility

SYNOPSIS         top

       e4crypt add_key -S [ -k keyring ] [-v] [-q] [ -p pad ] [ path ...
       e4crypt new_session
       e4crypt get_policy path ...
       e4crypt set_policy [ -p pad ] policy path ...

DESCRIPTION         top

       e4crypt performs encryption management for ext4 file systems.

COMMANDS         top

       e4crypt add_key [-vq] [-S salt ] [-k keyring ] [ -p pad ] [ path
       ... ]
              Prompts the user for a passphrase and inserts it into the
              specified keyring.  If no keyring is specified, e4crypt
              will use the session keyring if it exists or the user
              session keyring if it does not.

              The salt argument is interpreted in a number of different
              ways, depending on how its prefix value.  If the first two
              characters are "s:", then the rest of the argument will be
              used as an text string and used as the salt value.  If the
              first two characters are "0x", then the rest of the
              argument will be parsed as a hex string as used as the
              salt.  If the first characters are "f:" then the rest of
              the argument will be interpreted as a filename from which
              the salt value will be read.  If the string begins with a
              '/' character, it will similarly be treated as filename.
              Finally, if the salt argument can be parsed as a valid
              UUID, then the UUID value will be used as a salt value.

              The keyring argument specifies the keyring to which the
              key should be added.

              The pad value specifies the number of bytes of padding
              will be added to directory names for obfuscation purposes.
              Valid pad values are 4, 8, 16, and 32.

              If one or more directory paths are specified, e4crypt will
              try to set the policy of those directories to use the key
              just added by the add_key command.  If a salt was
              explicitly specified, then it will be used to derive the
              encryption key of those directories.  Otherwise a
              directory-specific default salt will be used.

       e4crypt get_policy path ...
              Print the policy for the directories specified on the
              command line.

       e4crypt new_session
              Give the invoking process (typically a shell) a new
              session keyring, discarding its old session keyring.

       e4crypt set_policy [ -p pad ] policy path ...
              Sets the policy for the directories specified on the
              command line.  All directories must be empty to set the
              policy; if the directory already has a policy established,
              e4crypt will validate that the policy matches what was
              specified.  A policy is an encryption key identifier
              consisting of 16 hexadecimal characters.

AUTHOR         top

       Written by Michael Halcrow <mhalcrow@google.com>, Ildar Muslukhov
       <muslukhovi@gmail.com>, and Theodore Ts'o <tytso@mit.edu>

SEE ALSO         top

       keyctl(1), mke2fs(8), mount(8).

COLOPHON         top

       This page is part of the e2fsprogs (utilities for ext2/3/4
       filesystems) project.  Information about the project can be found
       at ⟨http://e2fsprogs.sourceforge.net/⟩.  It is not known how to
       report bugs for this man page; if you know, please send a mail to
       man-pages@man7.org.  This page was obtained from the project's
       upstream Git repository
       ⟨git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git⟩ on
       2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-07.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

E2fsprogs version 1.47.0      February 2023                   E4CRYPT(8)