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/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 0032a9f..59ab793 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -377,6 +377,7 @@
#define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 0x00000010
#define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK 0x00000020
#define ECRYPTFS_GLOBAL_ENCFN_USE_FEK 0x00000040
+#define ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY 0x00000080
u32 flags;
struct list_head global_auth_tok_list;
struct mutex global_auth_tok_list_mutex;
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
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index cbd4e18..09eb529 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -208,7 +208,8 @@
ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
- ecryptfs_opt_unlink_sigs, ecryptfs_opt_err };
+ ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
+ ecryptfs_opt_err };
static const match_table_t tokens = {
{ecryptfs_opt_sig, "sig=%s"},
@@ -223,6 +224,7 @@
{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
{ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
+ {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
{ecryptfs_opt_err, NULL}
};
@@ -406,6 +408,10 @@
case ecryptfs_opt_unlink_sigs:
mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
break;
+ case ecryptfs_opt_mount_auth_tok_only:
+ mount_crypt_stat->flags |=
+ ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
+ break;
case ecryptfs_opt_err:
default:
printk(KERN_WARNING