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path: root/fs/ext4/crypto_key.c
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2015-07-22ext4 crypto: fix spelling typo in commentLaurent Navet1-1/+1
Signed-off-by: Laurent Navet <laurent.navet@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-07-22ext4 crypto: exit cleanly if ext4_derive_key_aes() failsLaurent Navet1-0/+2
Return value of ext4_derive_key_aes() is stored but not used. Add test to exit cleanly if ext4_derive_key_aes() fail. Also fix coverity CID 1309760. Signed-off-by: Laurent Navet <laurent.navet@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-31ext4 crypto: use per-inode tfm structureTheodore Ts'o1-30/+78
As suggested by Herbert Xu, we shouldn't allocate a new tfm each time we read or write a page. Instead we can use a single tfm hanging off the inode's crypt_info structure for all of our encryption needs for that inode, since the tfm can be used by multiple crypto requests in parallel. Also use cmpxchg() to avoid races that could result in crypt_info structure getting doubly allocated or doubly freed. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-18ext4 crypto: get rid of ci_mode from struct ext4_crypt_infoTheodore Ts'o1-6/+5
The ci_mode field was superfluous, and getting rid of it gets rid of an unused hole in the structure. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-18ext4 crypto: use slab cachesTheodore Ts'o1-3/+9
Use slab caches the ext4_crypto_ctx and ext4_crypt_info structures for slighly better memory efficiency and debuggability. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-18ext4 crypto: reorganize how we store keys in the inodeTheodore Ts'o1-17/+57
This is a pretty massive patch which does a number of different things: 1) The per-inode encryption information is now stored in an allocated data structure, ext4_crypt_info, instead of directly in the node. This reduces the size usage of an in-memory inode when it is not using encryption. 2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode encryption structure instead. This remove an unnecessary memory allocation and free for the fname_crypto_ctx as well as allowing us to reuse the ctfm in a directory for multiple lookups and file creations. 3) We also cache the inode's policy information in the ext4_crypt_info structure so we don't have to continually read it out of the extended attributes. 4) We now keep the keyring key in the inode's encryption structure instead of releasing it after we are done using it to derive the per-inode key. This allows us to test to see if the key has been revoked; if it has, we prevent the use of the derived key and free it. 5) When an inode is released (or when the derived key is freed), we will use memset_explicit() to zero out the derived key, so it's not left hanging around in memory. This implies that when a user logs out, it is important to first revoke the key, and then unlink it, and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to release any decrypted pages and dcache entries from the system caches. 6) All this, and we also shrink the number of lines of code by around 100. :-) Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-18ext4 crypto: separate kernel and userspace structure for the keyTheodore Ts'o1-10/+11
Use struct ext4_encryption_key only for the master key passed via the kernel keyring. For internal kernel space users, we now use struct ext4_crypt_info. This will allow us to put information from the policy structure so we can cache it and avoid needing to constantly looking up the extended attribute. We will do this in a spearate patch. This patch is mostly mechnical to make it easier for patch review. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-01ext4 crypto: add padding to filenames before encryptingTheodore Ts'o1-0/+1
This obscures the length of the filenames, to decrease the amount of information leakage. By default, we pad the filenames to the next 4 byte boundaries. This costs nothing, since the directory entries are aligned to 4 byte boundaries anyway. Filenames can also be padded to 8, 16, or 32 bytes, which will consume more directory space. Change-Id: Ibb7a0fb76d2c48e2061240a709358ff40b14f322 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-04-16ext4 crypto: enable encryption feature flagTheodore Ts'o1-12/+15
Also add the test dummy encryption mode flag so we can more easily test the encryption patches using xfstests. Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-04-12ext4 crypto: add encryption key management facilitiesMichael Halcrow1-0/+162
Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Ildar Muslukhov <muslukhovi@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>