xref: /openbmc/linux/net/tipc/crypto.h (revision 37744fee)
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 
71 /**
72  * TIPC encryption message format:
73  *
74  *     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
75  *     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
76  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77  * w0:|Ver=7| User  |D|TX |RX |K|                 Rsvd                |
78  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
79  * w1:|                             Seqno                             |
80  * w2:|                           (8 octets)                          |
81  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
82  * w3:\                            Prevnode                           \
83  *    /                        (4 or 16 octets)                       /
84  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
85  *    \                                                               \
86  *    /       Encrypted complete TIPC V2 header and user data         /
87  *    \                                                               \
88  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
89  *    |                                                               |
90  *    |                             AuthTag                           |
91  *    |                           (16 octets)                         |
92  *    |                                                               |
93  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
94  *
95  * Word0:
96  *	Ver	: = 7 i.e. TIPC encryption message version
97  *	User	: = 7 (for LINK_PROTOCOL); = 13 (for LINK_CONFIG) or = 0
98  *	D	: The destined bit i.e. the message's destination node is
99  *	          "known" or not at the message encryption
100  *	TX	: TX key used for the message encryption
101  *	RX	: Currently RX active key corresponding to the destination
102  *	          node's TX key (when the "D" bit is set)
103  *	K	: Keep-alive bit (for RPS, LINK_PROTOCOL/STATE_MSG only)
104  *	Rsvd	: Reserved bit, field
105  * Word1-2:
106  *	Seqno	: The 64-bit sequence number of the encrypted message, also
107  *		  part of the nonce used for the message encryption/decryption
108  * Word3-:
109  *	Prevnode: The source node address, or ID in case LINK_CONFIG only
110  *	AuthTag	: The authentication tag for the message integrity checking
111  *		  generated by the message encryption
112  */
113 struct tipc_ehdr {
114 	union {
115 		struct {
116 #if defined(__LITTLE_ENDIAN_BITFIELD)
117 			__u8	destined:1,
118 				user:4,
119 				version:3;
120 			__u8	reserved_1:3,
121 				keepalive:1,
122 				rx_key_active:2,
123 				tx_key:2;
124 #elif defined(__BIG_ENDIAN_BITFIELD)
125 			__u8	version:3,
126 				user:4,
127 				destined:1;
128 			__u8	tx_key:2,
129 				rx_key_active:2,
130 				keepalive:1,
131 				reserved_1:3;
132 #else
133 #error  "Please fix <asm/byteorder.h>"
134 #endif
135 			__be16	reserved_2;
136 		} __packed;
137 		__be32 w0;
138 	};
139 	__be64 seqno;
140 	union {
141 		__be32 addr;
142 		__u8 id[NODE_ID_LEN]; /* For a LINK_CONFIG message only! */
143 	};
144 #define EHDR_SIZE	(offsetof(struct tipc_ehdr, addr) + sizeof(__be32))
145 #define EHDR_CFG_SIZE	(sizeof(struct tipc_ehdr))
146 #define EHDR_MIN_SIZE	(EHDR_SIZE)
147 #define EHDR_MAX_SIZE	(EHDR_CFG_SIZE)
148 #define EMSG_OVERHEAD	(EHDR_SIZE + TIPC_AES_GCM_TAG_SIZE)
149 } __packed;
150 
151 int tipc_crypto_start(struct tipc_crypto **crypto, struct net *net,
152 		      struct tipc_node *node);
153 void tipc_crypto_stop(struct tipc_crypto **crypto);
154 void tipc_crypto_timeout(struct tipc_crypto *rx);
155 int tipc_crypto_xmit(struct net *net, struct sk_buff **skb,
156 		     struct tipc_bearer *b, struct tipc_media_addr *dst,
157 		     struct tipc_node *__dnode);
158 int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx,
159 		    struct sk_buff **skb, struct tipc_bearer *b);
160 int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey,
161 			 u8 mode);
162 void tipc_crypto_key_flush(struct tipc_crypto *c);
163 int tipc_aead_key_validate(struct tipc_aead_key *ukey);
164 bool tipc_ehdr_validate(struct sk_buff *skb);
165 
166 #endif /* _TIPC_CRYPTO_H */
167 #endif
168