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

   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 -- http://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 */
  27struct 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;
  41error:
  42        return tkey;
  43}
  44