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authorMichael Halcrow <mhalcrow@google.com>2015-04-12 07:43:56 +0300
committerTheodore Ts'o <tytso@mit.edu>2015-04-12 07:43:56 +0300
commitb30ab0e03407d2aa2d9316cba199c757e4bfc8ad (patch)
tree900754eb3fe069f90bb5ea2c1df1ed88cf701eb5 /fs/ext4/crypto_policy.c
parent9bd8212f981ea6375911fe055382ad7529be5b28 (diff)
downloadlinux-b30ab0e03407d2aa2d9316cba199c757e4bfc8ad.tar.xz
ext4 crypto: add ext4 encryption facilities
On encrypt, we will re-assign the buffer_heads to point to a bounce page rather than the control_page (which is the original page to write that contains the plaintext). The block I/O occurs against the bounce page. On write completion, we re-assign the buffer_heads to the original plaintext page. On decrypt, we will attach a read completion callback to the bio struct. This read completion will decrypt the read contents in-place prior to setting the page up-to-date. The current encryption mode, AES-256-XTS, lacks cryptographic integrity. AES-256-GCM is in-plan, but we will need to devise a mechanism for handling the integrity data. Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Ildar Muslukhov <ildarm@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/crypto_policy.c')
-rw-r--r--fs/ext4/crypto_policy.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
index 532b69c0afab..a4bf762b3ba9 100644
--- a/fs/ext4/crypto_policy.c
+++ b/fs/ext4/crypto_policy.c
@@ -52,6 +52,13 @@ static int ext4_create_encryption_context_from_policy(
ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
memcpy(ctx.master_key_descriptor, policy->master_key_descriptor,
EXT4_KEY_DESCRIPTOR_SIZE);
+ if (!ext4_valid_contents_enc_mode(policy->contents_encryption_mode)) {
+ printk(KERN_WARNING
+ "%s: Invalid contents encryption mode %d\n", __func__,
+ policy->contents_encryption_mode);
+ res = -EINVAL;
+ goto out;
+ }
ctx.contents_encryption_mode = policy->contents_encryption_mode;
ctx.filenames_encryption_mode = policy->filenames_encryption_mode;
BUILD_BUG_ON(sizeof(ctx.nonce) != EXT4_KEY_DERIVATION_NONCE_SIZE);
@@ -60,6 +67,7 @@ static int ext4_create_encryption_context_from_policy(
res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
sizeof(ctx), 0);
+out:
if (!res)
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
return res;