encrypted-keys: remove trusted-keys dependency

Encrypted keys are decrypted/encrypted using either a trusted-key or,
for those systems without a TPM, a user-defined key.  This patch
removes the trusted-keys and TCG_TPM dependencies.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

security/Kconfig

@@ -38,7 +38,9 @@ config TRUSTED_KEYS
 
 config ENCRYPTED_KEYS
 	tristate "ENCRYPTED KEYS"
-	depends on KEYS && TRUSTED_KEYS
+	depends on KEYS
+	select CRYPTO
+	select CRYPTO_HMAC
 	select CRYPTO_AES
 	select CRYPTO_CBC
 	select CRYPTO_SHA256

security/keys/encrypted-keys/Makefile

@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o ecryptfs_format.o
+obj-$(CONFIG_TRUSTED_KEYS) += masterkey_trusted.o

security/keys/encrypted-keys/encrypted.c

@@ -298,31 +298,6 @@ out:
 	return ascii_buf;
 }
 
-/*
- * request_trusted_key - request the trusted key
- *
- * Trusted keys are sealed to PCRs and other metadata. Although userspace
- * manages both trusted/encrypted key-types, like the encrypted key type
- * data, trusted key type data is not visible decrypted from userspace.
- */
-static struct key *request_trusted_key(const char *trusted_desc,
-				       u8 **master_key, size_t *master_keylen)
-{
-	struct trusted_key_payload *tpayload;
-	struct key *tkey;
-
-	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
-	if (IS_ERR(tkey))
-		goto error;
-
-	down_read(&tkey->sem);
-	tpayload = rcu_dereference(tkey->payload.data);
-	*master_key = tpayload->key;
-	*master_keylen = tpayload->key_len;
-error:
-	return tkey;
-}
-
 /*
  * request_user_key - request the user key
  *
@@ -469,8 +444,14 @@ static struct key *request_master_key(struct encrypted_key_payload *epayload,
 		goto out;
 
 	if (IS_ERR(mkey)) {
-		pr_info("encrypted_key: key %s not found",
-			epayload->master_desc);
+		int ret = PTR_ERR(epayload);
+
+		if (ret == -ENOTSUPP)
+			pr_info("encrypted_key: key %s not supported",
+				epayload->master_desc);
+		else
+			pr_info("encrypted_key: key %s not found",
+				epayload->master_desc);
 		goto out;
 	}
 

security/keys/encrypted-keys/encrypted.h

@@ -2,6 +2,17 @@
 #define __ENCRYPTED_KEY_H
 
 #define ENCRYPTED_DEBUG 0
+#ifdef CONFIG_TRUSTED_KEYS
+extern struct key *request_trusted_key(const char *trusted_desc,
+				       u8 **master_key, size_t *master_keylen);
+#else
+static inline struct key *request_trusted_key(const char *trusted_desc,
+					      u8 **master_key,
+					      size_t *master_keylen)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
 
 #if ENCRYPTED_DEBUG
 static inline void dump_master_key(const u8 *master_key, size_t master_keylen)

security/keys/encrypted-keys/masterkey_trusted.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * See Documentation/security/keys-trusted-encrypted.txt
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <keys/trusted-type.h>
+
+/*
+ * request_trusted_key - request the trusted key
+ *
+ * Trusted keys are sealed to PCRs and other metadata. Although userspace
+ * manages both trusted/encrypted key-types, like the encrypted key type
+ * data, trusted key type data is not visible decrypted from userspace.
+ */
+struct key *request_trusted_key(const char *trusted_desc,
+				u8 **master_key, size_t *master_keylen)
+{
+	struct trusted_key_payload *tpayload;
+	struct key *tkey;
+
+	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
+	if (IS_ERR(tkey))
+		goto error;
+
+	down_read(&tkey->sem);
+	tpayload = rcu_dereference(tkey->payload.data);
+	*master_key = tpayload->key;
+	*master_keylen = tpayload->key_len;
+error:
+	return tkey;
+}