[v4,0/4] fscrypt preparations for encryption+casefolding

Message

Eric Biggers Jan. 20, 2020, 4:43 a.m. UTC

This is a cleaned up version of the fscrypt patches to prepare for
directories that are both encrypted and casefolded.

Patches 1-3 start deriving a SipHash key for the new dirhash method that
will be used by encrypted+casefolded directories.  To avoid unnecessary
overhead, we only do this if the directory is actually casefolded.

Patch 4 modifies the fscrypt no-key names to always include the dirhash,
since with the new dirhash method the dirhash will no longer be
computable from the ciphertext filename without the key.  It also fixes
a longstanding issue where there could be collisions in the no-key
names, due to not using a proper cryptographic hash to abbreviate names.

For more information see the main patch series, which includes the
filesystem-specific changes:
https://lkml.kernel.org/linux-fscrypt/[e-mail]/T/#u

This applies to fscrypt.git#master.

Daniel Rosenberg (3):
  fscrypt: don't allow v1 policies with casefolding
  fscrypt: derive dirhash key for casefolded directories
  fscrypt: improve format of no-key names

Eric Biggers (1):
  fscrypt: clarify what is meant by a per-file key

 Documentation/filesystems/fscrypt.rst |  40 +++--
 fs/crypto/Kconfig                     |   1 +
 fs/crypto/fname.c                     | 239 ++++++++++++++++++++------
 fs/crypto/fscrypt_private.h           |  19 +-
 fs/crypto/hooks.c                     |  44 +++++
 fs/crypto/keysetup.c                  |  81 ++++++---
 fs/crypto/keysetup_v1.c               |   4 +-
 fs/crypto/policy.c                    |   7 +
 fs/inode.c                            |   3 +-
 include/linux/fscrypt.h               |  94 +++-------
 10 files changed, 360 insertions(+), 172 deletions(-)


base-commit: 2d8f7f119b0b2ce5e7ff0e8024b0763bf42b99c9