ecryptfs: added ecryptfs_mount_auth_tok_only mount parameter
This patch adds a new mount parameter 'ecryptfs_mount_auth_tok_only' to
force ecryptfs to use only authentication tokens which signature has
been specified at mount time with parameters 'ecryptfs_sig' and
'ecryptfs_fnek_sig'. In this way, after disabling the passthrough and
the encrypted view modes, it's possible to make available to users only
files encrypted with the specified authentication token.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
[Tyler: Clean up coding style errors found by checkpatch]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index e7f029f..b1f6858 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -459,6 +459,15 @@
if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
mount_crypt_stat, sig)) {
+ /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
+ * mount_crypt_stat structure, we prevent to use auth toks that
+ * are not inserted through the ecryptfs_add_global_auth_tok
+ * function.
+ */
+ if (mount_crypt_stat->flags
+ & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
+ return -EINVAL;
+
rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
sig);
} else