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.rst
  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 */
  31struct key *request_trusted_key(const char *trusted_desc,
  32                                const 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 = tkey->payload.data[0];
  43        *master_key = tpayload->key;
  44        *master_keylen = tpayload->key_len;
  45error:
  46        return tkey;
  47}
  48