aboutsummaryrefslogtreecommitdiffstats
path: root/net/tipc/crypto.h
blob: c3de769f49e8883c93c967e1cc4737f02a53f136 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/* SPDX-License-Identifier: GPL-2.0 */
/**
 * net/tipc/crypto.h: Include file for TIPC crypto
 *
 * Copyright (c) 2019, Ericsson AB
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#ifdef CONFIG_TIPC_CRYPTO
#ifndef _TIPC_CRYPTO_H
#define _TIPC_CRYPTO_H

#include "core.h"
#include "node.h"
#include "msg.h"
#include "bearer.h"

#define TIPC_EVERSION			7

/* AEAD aes(gcm) */
#define TIPC_AES_GCM_KEY_SIZE_128	16
#define TIPC_AES_GCM_KEY_SIZE_192	24
#define TIPC_AES_GCM_KEY_SIZE_256	32

#define TIPC_AES_GCM_SALT_SIZE		4
#define TIPC_AES_GCM_IV_SIZE		12
#define TIPC_AES_GCM_TAG_SIZE		16

/**
 * TIPC crypto modes:
 * - CLUSTER_KEY:
 *	One single key is used for both TX & RX in all nodes in the cluster.
 * - PER_NODE_KEY:
 *	Each nodes in the cluster has one TX key, for RX a node needs to know
 *	its peers' TX key for the decryption of messages from those nodes.
 */
enum {
	CLUSTER_KEY = 1,
	PER_NODE_KEY = (1 << 1),
};

extern int sysctl_tipc_max_tfms __read_mostly;

/**
 * TIPC encryption message format:
 *
 *     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
 *     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
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * w0:|Ver=7| User  |D|TX |RX |K|                 Rsvd                |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * w1:|                             Seqno                             |
 * w2:|                           (8 octets)                          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * w3:\                            Prevnode                           \
 *    /                        (4 or 16 octets)                       /
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    \                                                               \
 *    /       Encrypted complete TIPC V2 header and user data         /
 *    \                                                               \
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                                                               |
 *    |                             AuthTag                           |
 *    |                           (16 octets)                         |
 *    |                                                               |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * Word0:
 *	Ver	: = 7 i.e. TIPC encryption message version
 *	User	: = 7 (for LINK_PROTOCOL); = 13 (for LINK_CONFIG) or = 0
 *	D	: The destined bit i.e. the message's destination node is
 *	          "known" or not at the message encryption
 *	TX	: TX key used for the message encryption
 *	RX	: Currently RX active key corresponding to the destination
 *	          node's TX key (when the "D" bit is set)
 *	K	: Keep-alive bit (for RPS, LINK_PROTOCOL/STATE_MSG only)
 *	Rsvd	: Reserved bit, field
 * Word1-2:
 *	Seqno	: The 64-bit sequence number of the encrypted message, also
 *		  part of the nonce used for the message encryption/decryption
 * Word3-:
 *	Prevnode: The source node address, or ID in case LINK_CONFIG only
 *	AuthTag	: The authentication tag for the message integrity checking
 *		  generated by the message encryption
 */
struct tipc_ehdr {
	union {
		struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
			__u8	destined:1,
				user:4,
				version:3;
			__u8	reserved_1:3,
				keepalive:1,
				rx_key_active:2,
				tx_key:2;
#elif defined(__BIG_ENDIAN_BITFIELD)
			__u8	version:3,
				user:4,
				destined:1;
			__u8	tx_key:2,
				rx_key_active:2,
				keepalive:1,
				reserved_1:3;
#else
#error  "Please fix <asm/byteorder.h>"
#endif
			__be16	reserved_2;
		} __packed;
		__be32 w0;
	};
	__be64 seqno;
	union {
		__be32 addr;
		__u8 id[NODE_ID_LEN]; /* For a LINK_CONFIG message only! */
	};
#define EHDR_SIZE	(offsetof(struct tipc_ehdr, addr) + sizeof(__be32))
#define EHDR_CFG_SIZE	(sizeof(struct tipc_ehdr))
#define EHDR_MIN_SIZE	(EHDR_SIZE)
#define EHDR_MAX_SIZE	(EHDR_CFG_SIZE)
#define EMSG_OVERHEAD	(EHDR_SIZE + TIPC_AES_GCM_TAG_SIZE)
} __packed;

int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
		      struct tipc_node *node);
void tipc_crypto_stop(struct tipc_crypto **crypto);
void tipc_crypto_timeout(struct tipc_crypto *rx);
int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
		     struct tipc_bearer *b, struct tipc_media_addr *dst,
		     struct tipc_node *__dnode);
int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
		    struct sk_buff **skb, struct tipc_bearer *b);
int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
			 u8 mode);
void tipc_crypto_key_flush(struct tipc_crypto *c);
int tipc_aead_key_validate(struct tipc_aead_key *ukey);
bool tipc_ehdr_validate(struct sk_buff *skb);

#endif /* _TIPC_CRYPTO_H */
#endif