xref: /linux/security/keys/encrypted-keys/masterkey_trusted.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2010 IBM Corporation
4  * Copyright (C) 2010 Politecnico di Torino, Italy
5  *                    TORSEC group -- https://security.polito.it
6  *
7  * Authors:
8  * Mimi Zohar <zohar@us.ibm.com>
9  * Roberto Sassu <roberto.sassu@polito.it>
10  *
11  * See Documentation/security/keys/trusted-encrypted.rst
12  */
13 
14 #include <linux/uaccess.h>
15 #include <linux/err.h>
16 #include <keys/trusted-type.h>
17 #include <keys/encrypted-type.h>
18 #include "encrypted.h"
19 
20 /*
21  * request_trusted_key - request the trusted key
22  *
23  * Trusted keys are sealed to PCRs and other metadata. Although userspace
24  * manages both trusted/encrypted key-types, like the encrypted key type
25  * data, trusted key type data is not visible decrypted from userspace.
26  */
request_trusted_key(const char * trusted_desc,const u8 ** master_key,size_t * master_keylen)27 struct key *request_trusted_key(const char *trusted_desc,
28 				const u8 **master_key, size_t *master_keylen)
29 {
30 	struct trusted_key_payload *tpayload;
31 	struct key *tkey;
32 
33 	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
34 	if (IS_ERR(tkey))
35 		goto error;
36 
37 	down_read(&tkey->sem);
38 	tpayload = tkey->payload.data[0];
39 	*master_key = tpayload->key;
40 	*master_keylen = tpayload->key_len;
41 error:
42 	return tkey;
43 }
44