/* SPDX-License-Identifier: GPL-2.0-or-later */
/* RxRPC key type
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#ifndef _KEYS_RXRPC_TYPE_H
#define _KEYS_RXRPC_TYPE_H

#include <linux/key.h>
#include <crypto/krb5.h>

/*
 * key type for AF_RXRPC keys
 */
extern struct key_type key_type_rxrpc;

extern struct key *rxrpc_get_null_key(const char *);

/*
 * RxRPC key for Kerberos IV (type-2 security)
 */
struct rxkad_key {
        u32     vice_id;
        u32     start;                  /* time at which ticket starts */
        u32     expiry;                 /* time at which ticket expires */
        u32     kvno;                   /* key version number */
        u8      primary_flag;           /* T if key for primary cell for this user */
        u16     ticket_len;             /* length of ticket[] */
        u8      session_key[8];         /* DES session key */
        u8      ticket[];               /* the encrypted ticket */
};

/*
 * RxRPC key for YFS-RxGK (type-6 security)
 */
struct rxgk_key {
        s64             begintime;      /* Time at which the ticket starts */
        s64             endtime;        /* Time at which the ticket ends */
        u64             lifetime;       /* Maximum lifespan of a connection (seconds) */
        u64             bytelife;       /* Maximum number of bytes on a connection */
        unsigned int    enctype;        /* Encoding type */
        s8              level;          /* Negotiated security RXRPC_SECURITY_PLAIN/AUTH/ENCRYPT */
        struct krb5_buffer key;         /* Master key, K0 */
        struct krb5_buffer ticket;      /* Ticket to be passed to server */
        u8              _key[];         /* Key storage */
};

/*
 * list of tokens attached to an rxrpc key
 */
struct rxrpc_key_token {
        u16     security_index;         /* RxRPC header security index */
        bool    no_leak_key;            /* Don't copy the key to userspace */
        struct rxrpc_key_token *next;   /* the next token in the list */
        union {
                struct rxkad_key *kad;
                struct rxgk_key *rxgk;
        };
};

/*
 * structure of raw payloads passed to add_key() or instantiate key
 */
struct rxrpc_key_data_v1 {
        u16             security_index;
        u16             ticket_length;
        u32             expiry;                 /* time_t */
        u32             kvno;
        u8              session_key[8];
        u8              ticket[];
};

/*
 * AF_RXRPC key payload derived from XDR format
 * - based on openafs-1.4.10/src/auth/afs_token.xg
 */
#define AFSTOKEN_LENGTH_MAX             16384   /* max payload size */
#define AFSTOKEN_STRING_MAX             256     /* max small string length */
#define AFSTOKEN_DATA_MAX               64      /* max small data length */
#define AFSTOKEN_CELL_MAX               64      /* max cellname length */
#define AFSTOKEN_MAX                    8       /* max tokens per payload */
#define AFSTOKEN_BDATALN_MAX            16384   /* max big data length */
#define AFSTOKEN_RK_TIX_MAX             12000   /* max RxKAD ticket size */
#define AFSTOKEN_GK_KEY_MAX             64      /* max GSSAPI key size */
#define AFSTOKEN_GK_TOKEN_MAX           16384   /* max GSSAPI token size */

/*
 * Truncate a time64_t to the range from 1970 to 2106 as in the network
 * protocol.
 */
static inline u32 rxrpc_time64_to_u32(time64_t time)
{
        if (time < 0)
                return 0;

        if (time > UINT_MAX)
                return UINT_MAX;

        return (u32)time;
}

/*
 * Extend u32 back to time64_t using the same 1970-2106 range.
 */
static inline time64_t rxrpc_u32_to_time64(u32 time)
{
        return (time64_t)time;
}

#endif /* _KEYS_RXRPC_TYPE_H */