eCryptfs: added support for the encrypted key type

The function ecryptfs_keyring_auth_tok_for_sig() has been modified in order
to search keys of both 'user' and 'encrypted' types.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

fs/ecryptfs/ecryptfs_kernel.h

@@ -29,6 +29,7 @@
 #define ECRYPTFS_KERNEL_H
 
 #include <keys/user-type.h>
+#include <keys/encrypted-type.h>
 #include <linux/fs.h>
 #include <linux/fs_stack.h>
 #include <linux/namei.h>
@@ -78,11 +79,47 @@ struct ecryptfs_page_crypt_context {
 	} param;
 };
 
+#if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE)
+static inline struct ecryptfs_auth_tok *
+ecryptfs_get_encrypted_key_payload_data(struct key *key)
+{
+	if (key->type == &key_type_encrypted)
+		return (struct ecryptfs_auth_tok *)
+			(&((struct encrypted_key_payload *)key->payload.data)->payload_data);
+	else
+		return NULL;
+}
+
+static inline struct key *ecryptfs_get_encrypted_key(char *sig)
+{
+	return request_key(&key_type_encrypted, sig, NULL);
+}
+
+#else
+static inline struct ecryptfs_auth_tok *
+ecryptfs_get_encrypted_key_payload_data(struct key *key)
+{
+	return NULL;
+}
+
+static inline struct key *ecryptfs_get_encrypted_key(char *sig)
+{
+	return ERR_PTR(-ENOKEY);
+}
+
+#endif /* CONFIG_ENCRYPTED_KEYS */
+
 static inline struct ecryptfs_auth_tok *
 ecryptfs_get_key_payload_data(struct key *key)
 {
+	struct ecryptfs_auth_tok *auth_tok;
+
+	auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
+	if (!auth_tok)
 		return (struct ecryptfs_auth_tok *)
-		(((struct user_key_payload*)key->payload.data)->data);
+			(((struct user_key_payload *)key->payload.data)->data);
+	else
+		return auth_tok;
 }
 
 #define ECRYPTFS_MAX_KEYSET_SIZE 1024

fs/ecryptfs/keystore.c

@@ -1634,6 +1634,8 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
 	int rc = 0;
 
 	(*auth_tok_key) = request_key(&key_type_user, sig, NULL);
+	if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
+		(*auth_tok_key) = ecryptfs_get_encrypted_key(sig);
 		if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
 			printk(KERN_ERR "Could not find key with description: [%s]\n",
 			      sig);
@@ -1641,6 +1643,7 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
 			(*auth_tok_key) = NULL;
 			goto out;
 		}
+	}
 	down_write(&(*auth_tok_key)->sem);
 	rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
 	if (rc) {