From fc1b6d6de2208774efd2a20bf0daddb02d18b1e0 Mon Sep 17 00:00:00 2001 From: Tuong Lien Date: Fri, 8 Nov 2019 12:05:11 +0700 Subject: tipc: introduce TIPC encryption & authentication This commit offers an option to encrypt and authenticate all messaging, including the neighbor discovery messages. The currently most advanced algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All encryption/decryption is done at the bearer layer, just before leaving or after entering TIPC. Supported features: - Encryption & authentication of all TIPC messages (header + data); - Two symmetric-key modes: Cluster and Per-node; - Automatic key switching; - Key-expired revoking (sequence number wrapped); - Lock-free encryption/decryption (RCU); - Asynchronous crypto, Intel AES-NI supported; - Multiple cipher transforms; - Logs & statistics; Two key modes: - Cluster key mode: One single key is used for both TX & RX in all nodes in the cluster. - Per-node key mode: Each nodes in the cluster has one specific TX key. For RX, a node requires its peers' TX key to be able to decrypt the messages from those peers. Key setting from user-space is performed via netlink by a user program (e.g. the iproute2 'tipc' tool). Internal key state machine: Attach Align(RX) +-+ +-+ | V | V +---------+ Attach +---------+ | IDLE |---------------->| PENDING |(user = 0) +---------+ +---------+ A A Switch| A | | | | | | Free(switch/revoked) | | (Free)| +----------------------+ | |Timeout | (TX) | | |(RX) | | | | | | v | +---------+ Switch +---------+ | PASSIVE |<----------------| ACTIVE | +---------+ (RX) +---------+ (user = 1) (user >= 1) The number of TFMs is 10 by default and can be changed via the procfs 'net/tipc/max_tfms'. At this moment, as for simplicity, this file is also used to print the crypto statistics at runtime: echo 0xfff1 > /proc/sys/net/tipc/max_tfms The patch defines a new TIPC version (v7) for the encryption message (- backward compatibility as well). The message is basically encapsulated as follows: +----------------------------------------------------------+ | TIPCv7 encryption | Original TIPCv2 | Authentication | | header | packet (encrypted) | Tag | +----------------------------------------------------------+ The throughput is about ~40% for small messages (compared with non- encryption) and ~9% for large messages. With the support from hardware crypto i.e. the Intel AES-NI CPU instructions, the throughput increases upto ~85% for small messages and ~55% for large messages. By default, the new feature is inactive (i.e. no encryption) until user sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO" in the kernel configuration to enable/disable the new code when needed. MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller --- net/tipc/crypto.h | 167 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 167 insertions(+) create mode 100644 net/tipc/crypto.h (limited to 'net/tipc/crypto.h') diff --git a/net/tipc/crypto.h b/net/tipc/crypto.h new file mode 100644 index 000000000000..c3de769f49e8 --- /dev/null +++ b/net/tipc/crypto.h @@ -0,0 +1,167 @@ +/* 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 " +#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 -- cgit v1.2.3-59-g8ed1b