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| author |   Daniel Rosenberg <drosen@google.com> | 2020-01-20 14:31:56 -0800 |
|---|---|---|
| committer |   Eric Biggers <ebiggers@google.com> | 2020-01-22 14:47:15 -0800 |
| commit | 6e1918cfb263acacd3fc9239127732b69de64695 (patch) | |
| tree | f568fcd5fbed7df8ff441c664f18be933593ebd7 /include/linux/fscrypt.h | |
| parent | fscrypt: add "fscrypt_" prefix to fname_encrypt() (diff) | |
| download | wireguard-linux-6e1918cfb263acacd3fc9239127732b69de64695.tar.xz wireguard-linux-6e1918cfb263acacd3fc9239127732b69de64695.zip | |
fscrypt: don't allow v1 policies with casefolding
Casefolded encrypted directories will use a new dirhash method that
requires a secret key. If the directory uses a v2 encryption policy,
it's easy to derive this key from the master key using HKDF. However,
v1 encryption policies don't provide a way to derive additional keys.
Therefore, don't allow casefolding on directories that use a v1 policy.
Specifically, make it so that trying to enable casefolding on a
directory that has a v1 policy fails, trying to set a v1 policy on a
casefolded directory fails, and trying to open a casefolded directory
that has a v1 policy (if one somehow exists on-disk) fails.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
[EB: improved commit message, updated fscrypt.rst, and other cleanups]
Link: https://lore.kernel.org/r/20200120223201.241390-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'include/linux/fscrypt.h')
| -rw-r--r-- | include/linux/fscrypt.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 6fe8d0f96a4a..3984eadd7023 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -263,6 +263,8 @@ extern int __fscrypt_prepare_rename(struct inode *old_dir, unsigned int flags); extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, struct fscrypt_name *fname); +extern int fscrypt_prepare_setflags(struct inode *inode, + unsigned int oldflags, unsigned int flags); extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, struct fscrypt_str *disk_link); @@ -519,6 +521,13 @@ static inline int __fscrypt_prepare_lookup(struct inode *dir, return -EOPNOTSUPP; } +static inline int fscrypt_prepare_setflags(struct inode *inode, + unsigned int oldflags, + unsigned int flags) +{ + return 0; +} + static inline int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, |