include/keys/asymmetric-type.h

   1 /* Asymmetric Public-key cryptography key type interface
   2  *
   3  * See Documentation/security/asymmetric-keys.txt
   4  *
   5  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
   6  * Written by David Howells (dhowells@redhat.com)
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public Licence
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the Licence, or (at your option) any later version.
  12  */
  13
  14 #ifndef _KEYS_ASYMMETRIC_TYPE_H
  15 #define _KEYS_ASYMMETRIC_TYPE_H
  16
  17 #include <linux/key-type.h>
  18
  19 extern struct key_type key_type_asymmetric;
  20
  21 /*
  22  * Identifiers for an asymmetric key ID.  We have three ways of looking up a
  23  * key derived from an X.509 certificate:
  24  *
  25  * (1) Serial Number & Issuer.  Non-optional.  This is the only valid way to
  26  *     map a PKCS#7 signature to an X.509 certificate.
  27  *
  28  * (2) Issuer & Subject Unique IDs.  Optional.  These were the original way to
  29  *     match X.509 certificates, but have fallen into disuse in favour of (3).
  30  *
  31  * (3) Auth & Subject Key Identifiers.  Optional.  SKIDs are only provided on
  32  *     CA keys that are intended to sign other keys, so don't appear in end
  33  *     user certificates unless forced.
  34  *
  35  * We could also support an PGP key identifier, which is just a SHA1 sum of the
  36  * public key and certain parameters, but since we don't support PGP keys at
  37  * the moment, we shall ignore those.
  38  *
  39  * What we actually do is provide a place where binary identifiers can be
  40  * stashed and then compare against them when checking for an id match.
  41  */
  42 struct asymmetric_key_id {
  43         unsigned short  len;
  44         unsigned char   data[];
  45 };
  46
  47 struct asymmetric_key_ids {
  48         void            *id[2];
  49 };
  50
  51 extern bool asymmetric_key_id_same(const struct asymmetric_key_id *kid1,
  52                                    const struct asymmetric_key_id *kid2);
  53
  54 extern bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
  55                                       const struct asymmetric_key_id *kid2);
  56
  57 extern struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1,
  58                                                             size_t len_1,
  59                                                             const void *val_2,
  60                                                             size_t len_2);
  61
  62 /*
  63  * The payload is at the discretion of the subtype.
  64  */
  65
  66 #endif /* _KEYS_ASYMMETRIC_TYPE_H */