/* Asymmetric Public-key cryptography key type interface
 *
 * See Documentation/security/asymmetric-keys.txt
 *
 * 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.
 */

#ifndef _KEYS_ASYMMETRIC_TYPE_H
#define _KEYS_ASYMMETRIC_TYPE_H

//#include <linux/key-type.h>
//#include <linux/verification.h>

#include <fltKernel.h>

// extern struct key_type key_type_asymmetric;

/*
 * The key payload is four words.  The asymmetric-type key uses them as
 * follows:
 */
enum asymmetric_payload_bits
{
    asym_crypto,  /* The data representing the key */
    asym_subtype, /* Pointer to an asymmetric_key_subtype struct */
    asym_key_ids, /* Pointer to an asymmetric_key_ids struct */
    asym_auth     /* The key's authorisation (signature, parent key ID) */
};

/*
 * Identifiers for an asymmetric key ID.  We have three ways of looking up a
 * key derived from an X.509 certificate:
 *
 * (1) Serial Number & Issuer.  Non-optional.  This is the only valid way to
 *     map a PKCS#7 signature to an X.509 certificate.
 *
 * (2) Issuer & Subject Unique IDs.  Optional.  These were the original way to
 *     match X.509 certificates, but have fallen into disuse in favour of (3).
 *
 * (3) Auth & Subject Key Identifiers.  Optional.  SKIDs are only provided on
 *     CA keys that are intended to sign other keys, so don't appear in end
 *     user certificates unless forced.
 *
 * We could also support an PGP key identifier, which is just a SHA1 sum of the
 * public key and certain parameters, but since we don't support PGP keys at
 * the moment, we shall ignore those.
 *
 * What we actually do is provide a place where binary identifiers can be
 * stashed and then compare against them when checking for an id match.
 */
struct asymmetric_key_id
{
    unsigned short len;
    unsigned char data[1];
};

struct asymmetric_key_ids
{
    void *id[2];
};

extern unsigned char
asymmetric_key_id_same(const struct asymmetric_key_id *kid1, const struct asymmetric_key_id *kid2);

// extern bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
//				      const struct asymmetric_key_id *kid2);

extern struct asymmetric_key_id *
asymmetric_key_generate_id(const void *val_1, size_t len_1, const void *val_2, size_t len_2);
// static inline
// const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key)
//{
//	return key->payload.data[asym_key_ids];
// }

// extern struct key *find_asymmetric_key(struct key *keyring,
//				       const struct asymmetric_key_id *id_0,
//				       const struct asymmetric_key_id *id_1,
//				       bool partial);

/*
 * The payload is at the discretion of the subtype.
 */

#endif /* _KEYS_ASYMMETRIC_TYPE_H */