LXR linux/kernel/system

   1/* System trusted keyring for trusted public keys
   2 *
   3 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public Licence
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the Licence, or (at your option) any later version.
  10 */
  11
  12#include <linux/export.h>
  13#include <linux/kernel.h>
  14#include <linux/sched.h>
  15#include <linux/cred.h>
  16#include <linux/err.h>
  17#include <keys/asymmetric-type.h>
  18#include <keys/system_keyring.h>
  19#include "module-internal.h"
  20
  21struct key *system_trusted_keyring;
  22EXPORT_SYMBOL_GPL(system_trusted_keyring);
  23#ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING
  24struct key *system_blacklist_keyring;
  25#endif
  26
  27extern __initconst const u8 system_certificate_list[];
  28extern __initconst const unsigned long system_certificate_list_size;
  29
  30/*
  31 * Load the compiled-in keys
  32 */
  33static __init int system_trusted_keyring_init(void)
  34{
  35        pr_notice("Initialise system trusted keyring\n");
  36
  37        system_trusted_keyring =
  38                keyring_alloc(".system_keyring",
  39                              KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
  40                              ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
  41                              KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
  42                              KEY_ALLOC_NOT_IN_QUOTA, NULL);
  43        if (IS_ERR(system_trusted_keyring))
  44                panic("Can't allocate system trusted keyring\n");
  45
  46        set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags);
  47
  48#ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING
  49        system_blacklist_keyring = keyring_alloc(".system_blacklist_keyring",
  50                                    KUIDT_INIT(0), KGIDT_INIT(0),
  51                                    current_cred(),
  52                                    (KEY_POS_ALL & ~KEY_POS_SETATTR) |
  53                                    KEY_USR_VIEW | KEY_USR_READ,
  54                                    KEY_ALLOC_NOT_IN_QUOTA, NULL);
  55        if (IS_ERR(system_blacklist_keyring))
  56                panic("Can't allocate system blacklist keyring\n");
  57
  58        set_bit(KEY_FLAG_TRUSTED_ONLY, &system_blacklist_keyring->flags);
  59#endif
  60
  61        return 0;
  62}
  63
  64/*
  65 * Must be initialised before we try and load the keys into the keyring.
  66 */
  67device_initcall(system_trusted_keyring_init);
  68
  69/*
  70 * Load the compiled-in list of X.509 certificates.
  71 */
  72static __init int load_system_certificate_list(void)
  73{
  74        key_ref_t key;
  75        const u8 *p, *end;
  76        size_t plen;
  77
  78        pr_notice("Loading compiled-in X.509 certificates\n");
  79
  80        p = system_certificate_list;
  81        end = p + system_certificate_list_size;
  82        while (p < end) {
  83                /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
  84                 * than 256 bytes in size.
  85                 */
  86                if (end - p < 4)
  87                        goto dodgy_cert;
  88                if (p[0] != 0x30 &&
  89                    p[1] != 0x82)
  90                        goto dodgy_cert;
  91                plen = (p[2] << 8) | p[3];
  92                plen += 4;
  93                if (plen > end - p)
  94                        goto dodgy_cert;
  95
  96                key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
  97                                           "asymmetric",
  98                                           NULL,
  99                                           p,
 100                                           plen,
 101                                           ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
 102                                           KEY_USR_VIEW | KEY_USR_READ),
 103                                           KEY_ALLOC_NOT_IN_QUOTA |
 104                                           KEY_ALLOC_TRUSTED);
 105                if (IS_ERR(key)) {
 106                        pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
 107                               PTR_ERR(key));
 108                } else {
 109                        set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
 110                        pr_notice("Loaded X.509 cert '%s'\n",
 111                                  key_ref_to_ptr(key)->description);
 112                        key_ref_put(key);
 113                }
 114                p += plen;
 115        }
 116
 117        return 0;
 118
 119dodgy_cert:
 120        pr_err("Problem parsing in-kernel X.509 certificate list\n");
 121        return 0;
 122}
 123late_initcall(load_system_certificate_list);
 124