1 /*
2  * Copyright (C) 2010 IBM Corporation
3  * Copyright (C) 2010 Politecnico di Torino, Italy
4  *                    TORSEC group -- http://security.polito.it
5  *
6  * Authors:
7  * Mimi Zohar <zohar@us.ibm.com>
8  * Roberto Sassu <roberto.sassu@polito.it>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation, version 2 of the License.
13  *
14  * See Documentation/security/keys-trusted-encrypted.txt
15  */
16 
17 #include <linux/uaccess.h>
18 #include <linux/module.h>
19 #include <linux/err.h>
20 #include <keys/trusted-type.h>
21 #include <keys/encrypted-type.h>
22 #include "encrypted.h"
23 
24 /*
25  * request_trusted_key - request the trusted key
26  *
27  * Trusted keys are sealed to PCRs and other metadata. Although userspace
28  * manages both trusted/encrypted key-types, like the encrypted key type
29  * data, trusted key type data is not visible decrypted from userspace.
30  */
31 struct key *request_trusted_key(const char *trusted_desc,
32 				u8 **master_key, size_t *master_keylen)
33 {
34 	struct trusted_key_payload *tpayload;
35 	struct key *tkey;
36 
37 	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
38 	if (IS_ERR(tkey))
39 		goto error;
40 
41 	down_read(&tkey->sem);
42 	tpayload = rcu_dereference(tkey->payload.data);
43 	*master_key = tpayload->key;
44 	*master_keylen = tpayload->key_len;
45 error:
46 	return tkey;
47 }
48