net/tipc/crypto.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * net/tipc/crypto.h: Include file for TIPC crypto
   4  *
   5  * Copyright (c) 2019, Ericsson AB
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 #ifdef CONFIG_TIPC_CRYPTO
  37 #ifndef _TIPC_CRYPTO_H
  38 #define _TIPC_CRYPTO_H
  39
  40 #include "core.h"
  41 #include "node.h"
  42 #include "msg.h"
  43 #include "bearer.h"
  44
  45 #define TIPC_EVERSION                   7
  46
  47 /* AEAD aes(gcm) */
  48 #define TIPC_AES_GCM_KEY_SIZE_128       16
  49 #define TIPC_AES_GCM_KEY_SIZE_192       24
  50 #define TIPC_AES_GCM_KEY_SIZE_256       32
  51
  52 #define TIPC_AES_GCM_SALT_SIZE          4
  53 #define TIPC_AES_GCM_IV_SIZE            12
  54 #define TIPC_AES_GCM_TAG_SIZE           16
  55
  56 /*
  57  * TIPC crypto modes:
  58  * - CLUSTER_KEY:
  59  *      One single key is used for both TX & RX in all nodes in the cluster.
  60  * - PER_NODE_KEY:
  61  *      Each nodes in the cluster has one TX key, for RX a node needs to know
  62  *      its peers' TX key for the decryption of messages from those nodes.
  63  */
  64 enum {
  65         CLUSTER_KEY = 1,
  66         PER_NODE_KEY = (1 << 1),
  67 };
  68
  69 extern int sysctl_tipc_max_tfms __read_mostly;
  70 extern int sysctl_tipc_key_exchange_enabled __read_mostly;
  71
  72 /*
  73  * TIPC encryption message format:
  74  *
  75  *     3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
  76  *     1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0
  77  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  78  * w0:|Ver=7| User  |D|TX |RX |K|M|N|             Rsvd                |
  79  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  80  * w1:|                             Seqno                             |
  81  * w2:|                           (8 octets)                          |
  82  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  83  * w3:\                            Prevnode                           \
  84  *    /                        (4 or 16 octets)                       /
  85  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86  *    \                                                               \
  87  *    /       Encrypted complete TIPC V2 header and user data         /
  88  *    \                                                               \
  89  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  90  *    |                                                               |
  91  *    |                             AuthTag                           |
  92  *    |                           (16 octets)                         |
  93  *    |                                                               |
  94  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  *
  96  * Word0:
  97  *      Ver     : = 7 i.e. TIPC encryption message version
  98  *      User    : = 7 (for LINK_PROTOCOL); = 13 (for LINK_CONFIG) or = 0
  99  *      D       : The destined bit i.e. the message's destination node is
 100  *                "known" or not at the message encryption
 101  *      TX      : TX key used for the message encryption
 102  *      RX      : Currently RX active key corresponding to the destination
 103  *                node's TX key (when the "D" bit is set)
 104  *      K       : Keep-alive bit (for RPS, LINK_PROTOCOL/STATE_MSG only)
 105  *      M       : Bit indicates if sender has master key
 106  *      N       : Bit indicates if sender has no RX keys corresponding to the
 107  *                receiver's TX (when the "D" bit is set)
 108  *      Rsvd    : Reserved bit, field
 109  * Word1-2:
 110  *      Seqno   : The 64-bit sequence number of the encrypted message, also
 111  *                part of the nonce used for the message encryption/decryption
 112  * Word3-:
 113  *      Prevnode: The source node address, or ID in case LINK_CONFIG only
 114  *      AuthTag : The authentication tag for the message integrity checking
 115  *                generated by the message encryption
 116  */
 117 struct tipc_ehdr {
 118         union {
 119                 struct {
 120 #if defined(__LITTLE_ENDIAN_BITFIELD)
 121                         __u8    destined:1,
 122                                 user:4,
 123                                 version:3;
 124                         __u8    reserved_1:1,
 125                                 rx_nokey:1,
 126                                 master_key:1,
 127                                 keepalive:1,
 128                                 rx_key_active:2,
 129                                 tx_key:2;
 130 #elif defined(__BIG_ENDIAN_BITFIELD)
 131                         __u8    version:3,
 132                                 user:4,
 133                                 destined:1;
 134                         __u8    tx_key:2,
 135                                 rx_key_active:2,
 136                                 keepalive:1,
 137                                 master_key:1,
 138                                 rx_nokey:1,
 139                                 reserved_1:1;
 140 #else
 141 #error  "Please fix <asm/byteorder.h>"
 142 #endif
 143                         __be16  reserved_2;
 144                 } __packed;
 145                 __be32 w0;
 146         };
 147         __be64 seqno;
 148         union {
 149                 __be32 addr;
 150                 __u8 id[NODE_ID_LEN]; /* For a LINK_CONFIG message only! */
 151         };
 152 #define EHDR_SIZE       (offsetof(struct tipc_ehdr, addr) + sizeof(__be32))
 153 #define EHDR_CFG_SIZE   (sizeof(struct tipc_ehdr))
 154 #define EHDR_MIN_SIZE   (EHDR_SIZE)
 155 #define EHDR_MAX_SIZE   (EHDR_CFG_SIZE)
 156 #define EMSG_OVERHEAD   (EHDR_SIZE + TIPC_AES_GCM_TAG_SIZE)
 157 } __packed;
 158
 159 int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
 160                       struct tipc_node *node);
 161 void tipc_crypto_stop(struct tipc_crypto **crypto);
 162 void tipc_crypto_timeout(struct tipc_crypto *rx);
 163 int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
 164                      struct tipc_bearer *b, struct tipc_media_addr *dst,
 165                      struct tipc_node *__dnode);
 166 int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
 167                     struct sk_buff **skb, struct tipc_bearer *b);
 168 int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
 169                          u8 mode, bool master_key);
 170 void tipc_crypto_key_flush(struct tipc_crypto *c);
 171 int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key,
 172                           struct tipc_node *dest);
 173 void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb);
 174 void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed,
 175                                 u32 new_intv);
 176 int tipc_aead_key_validate(struct tipc_aead_key *ukey, struct genl_info *info);
 177 bool tipc_ehdr_validate(struct sk_buff *skb);
 178
 179 static inline u32 msg_key_gen(struct tipc_msg *m)
 180 {
 181         return msg_bits(m, 4, 16, 0xffff);
 182 }
 183
 184 static inline void msg_set_key_gen(struct tipc_msg *m, u32 gen)
 185 {
 186         msg_set_bits(m, 4, 16, 0xffff, gen);
 187 }
 188
 189 static inline u32 msg_key_mode(struct tipc_msg *m)
 190 {
 191         return msg_bits(m, 4, 0, 0xf);
 192 }
 193
 194 static inline void msg_set_key_mode(struct tipc_msg *m, u32 mode)
 195 {
 196         msg_set_bits(m, 4, 0, 0xf, mode);
 197 }
 198
 199 #endif /* _TIPC_CRYPTO_H */
 200 #endif