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
msg_key_gen(struct tipc_msg * m)179 static inline u32 msg_key_gen(struct tipc_msg *m)
180 {
181 return msg_bits(m, 4, 16, 0xffff);
182 }
183
msg_set_key_gen(struct tipc_msg * m,u32 gen)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
msg_key_mode(struct tipc_msg * m)189 static inline u32 msg_key_mode(struct tipc_msg *m)
190 {
191 return msg_bits(m, 4, 0, 0xf);
192 }
193
msg_set_key_mode(struct tipc_msg * m,u32 mode)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
