/* System trusted keyring for trusted public keys
   *
   * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public Licence
   * as published by the Free Software Foundation; either version
   * 2 of the Licence, or (at your option) any later version.
   */
  
  #include <linux/export.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/cred.h>
  #include <linux/err.h>
  #include <keys/asymmetric-type.h>
  #include <keys/system_keyring.h>
  #include "module-internal.h"
  
  struct key *system_trusted_keyring;
  EXPORT_SYMBOL_GPL(system_trusted_keyring);
  
  extern __initconst const u8 system_certificate_list[];

  extern __initconst const unsigned long system_certificate_list_size;

  
  /*
   * Load the compiled-in keys
   */
  static __init int system_trusted_keyring_init(void)
  {
  	pr_notice("Initialise system trusted keyring
  ");
  
  	system_trusted_keyring =
  		keyring_alloc(".system_keyring",
  			      KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
  			      ((KEY_POS_ALL & ~KEY_POS_SETATTR) |

  			      KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),

  			      KEY_ALLOC_NOT_IN_QUOTA, NULL);
  	if (IS_ERR(system_trusted_keyring))
  		panic("Can't allocate system trusted keyring
  ");

  	set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags);

  	return 0;
  }
  
  /*
   * Must be initialised before we try and load the keys into the keyring.
   */
  device_initcall(system_trusted_keyring_init);
  
  /*
   * Load the compiled-in list of X.509 certificates.
   */
  static __init int load_system_certificate_list(void)
  {
  	key_ref_t key;
  	const u8 *p, *end;
  	size_t plen;
  
  	pr_notice("Loading compiled-in X.509 certificates
  ");

  	p = system_certificate_list;

  	end = p + system_certificate_list_size;

  	while (p < end) {
  		/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
  		 * than 256 bytes in size.
  		 */
  		if (end - p < 4)
  			goto dodgy_cert;
  		if (p[0] != 0x30 &&
  		    p[1] != 0x82)
  			goto dodgy_cert;
  		plen = (p[2] << 8) | p[3];
  		plen += 4;
  		if (plen > end - p)
  			goto dodgy_cert;
  
  		key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
  					   "asymmetric",
  					   NULL,
  					   p,
  					   plen,

  					   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
  					   KEY_USR_VIEW | KEY_USR_READ),

  					   KEY_ALLOC_NOT_IN_QUOTA |
  					   KEY_ALLOC_TRUSTED);

  		if (IS_ERR(key)) {
  			pr_err("Problem loading in-kernel X.509 certificate (%ld)
  ",
  			       PTR_ERR(key));
  		} else {

  			set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);

  			pr_notice("Loaded X.509 cert '%s'
  ",
  				  key_ref_to_ptr(key)->description);
  			key_ref_put(key);
  		}
  		p += plen;
  	}
  
  	return 0;
  
  dodgy_cert:
  	pr_err("Problem parsing in-kernel X.509 certificate list
  ");
  	return 0;
  }
  late_initcall(load_system_certificate_list);