LXR linux/security/keys/encrypted-keys/masterkey

   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
  22/*
  23 * request_trusted_key - request the trusted key
  24 *
  25 * Trusted keys are sealed to PCRs and other metadata. Although userspace
  26 * manages both trusted/encrypted key-types, like the encrypted key type
  27 * data, trusted key type data is not visible decrypted from userspace.
  28 */
  29struct key *request_trusted_key(const char *trusted_desc,
  30                                u8 **master_key, size_t *master_keylen)
  31{
  32        struct trusted_key_payload *tpayload;
  33        struct key *tkey;
  34
  35        tkey = request_key(&key_type_trusted, trusted_desc, NULL);
  36        if (IS_ERR(tkey))
  37                goto error;
  38
  39        down_read(&tkey->sem);
  40        tpayload = rcu_dereference(tkey->payload.data);
  41        *master_key = tpayload->key;
  42        *master_keylen = tpayload->key_len;
  43error:
  44        return tkey;
  45}
  46