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 201