// SPDX-License-Identifier: GPL-2.0 /* * net/tipc/crypto.c: TIPC crypto for key handling & packet en/decryption * * 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. */ #include <crypto/aead.h> #include <crypto/aes.h> #include <crypto/rng.h> #include "crypto.h" #include "msg.h" #include "bcast.h" #define TIPC_TX_GRACE_PERIOD … #define TIPC_TX_LASTING_TIME … #define TIPC_RX_ACTIVE_LIM … #define TIPC_RX_PASSIVE_LIM … #define TIPC_MAX_TFMS_DEF … #define TIPC_MAX_TFMS_LIM … #define TIPC_REKEYING_INTV_DEF … /* * TIPC Key ids */ enum { … }; /* * TIPC Crypto statistics */ enum { … }; /* TIPC crypto statistics' header */ static const char *hstats[MAX_STATS] = …; /* Max TFMs number per key */ int sysctl_tipc_max_tfms __read_mostly = …; /* Key exchange switch, default: on */ int sysctl_tipc_key_exchange_enabled __read_mostly = …; /* * struct tipc_key - TIPC keys' status indicator * * 7 6 5 4 3 2 1 0 * +-----+-----+-----+-----+-----+-----+-----+-----+ * key: | (reserved)|passive idx| active idx|pending idx| * +-----+-----+-----+-----+-----+-----+-----+-----+ */ struct tipc_key { … }; /** * struct tipc_tfm - TIPC TFM structure to form a list of TFMs * @tfm: cipher handle/key * @list: linked list of TFMs */ struct tipc_tfm { … }; /** * struct tipc_aead - TIPC AEAD key structure * @tfm_entry: per-cpu pointer to one entry in TFM list * @crypto: TIPC crypto owns this key * @cloned: reference to the source key in case cloning * @users: the number of the key users (TX/RX) * @salt: the key's SALT value * @authsize: authentication tag size (max = 16) * @mode: crypto mode is applied to the key * @hint: a hint for user key * @rcu: struct rcu_head * @key: the aead key * @gen: the key's generation * @seqno: the key seqno (cluster scope) * @refcnt: the key reference counter */ struct tipc_aead { … } ____cacheline_aligned; /** * struct tipc_crypto_stats - TIPC Crypto statistics * @stat: array of crypto statistics */ struct tipc_crypto_stats { … }; /** * struct tipc_crypto - TIPC TX/RX crypto structure * @net: struct net * @node: TIPC node (RX) * @aead: array of pointers to AEAD keys for encryption/decryption * @peer_rx_active: replicated peer RX active key index * @key_gen: TX/RX key generation * @key: the key states * @skey_mode: session key's mode * @skey: received session key * @wq: common workqueue on TX crypto * @work: delayed work sched for TX/RX * @key_distr: key distributing state * @rekeying_intv: rekeying interval (in minutes) * @stats: the crypto statistics * @name: the crypto name * @sndnxt: the per-peer sndnxt (TX) * @timer1: general timer 1 (jiffies) * @timer2: general timer 2 (jiffies) * @working: the crypto is working or not * @key_master: flag indicates if master key exists * @legacy_user: flag indicates if a peer joins w/o master key (for bwd comp.) * @nokey: no key indication * @flags: combined flags field * @lock: tipc_key lock */ struct tipc_crypto { … } ____cacheline_aligned; /* struct tipc_crypto_tx_ctx - TX context for callbacks */ struct tipc_crypto_tx_ctx { … }; /* struct tipc_crypto_rx_ctx - RX context for callbacks */ struct tipc_crypto_rx_ctx { … }; static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead); static inline void tipc_aead_put(struct tipc_aead *aead); static void tipc_aead_free(struct rcu_head *rp); static int tipc_aead_users(struct tipc_aead __rcu *aead); static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim); static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim); static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val); static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead); static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey, u8 mode); static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src); static void *tipc_aead_mem_alloc(struct crypto_aead *tfm, unsigned int crypto_ctx_size, u8 **iv, struct aead_request **req, struct scatterlist **sg, int nsg); static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode); static void tipc_aead_encrypt_done(void *data, int err); static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b); static void tipc_aead_decrypt_done(void *data, int err); static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr); static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead, u8 tx_key, struct sk_buff *skb, struct tipc_crypto *__rx); static inline void tipc_crypto_key_set_state(struct tipc_crypto *c, u8 new_passive, u8 new_active, u8 new_pending); static int tipc_crypto_key_attach(struct tipc_crypto *c, struct tipc_aead *aead, u8 pos, bool master_key); static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending); static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx, struct tipc_crypto *rx, struct sk_buff *skb, u8 tx_key); static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb); static int tipc_crypto_key_revoke(struct net *net, u8 tx_key); static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode, u8 type); static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead, struct tipc_bearer *b, struct sk_buff **skb, int err); static void tipc_crypto_do_cmd(struct net *net, int cmd); static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf); static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new, char *buf); static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey, u16 gen, u8 mode, u32 dnode); static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr); static void tipc_crypto_work_tx(struct work_struct *work); static void tipc_crypto_work_rx(struct work_struct *work); static int tipc_aead_key_generate(struct tipc_aead_key *skey); #define is_tx(crypto) … #define is_rx(crypto) … #define key_next(cur) … #define tipc_aead_rcu_ptr(rcu_ptr, lock) … #define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) … #define tipc_crypto_key_detach(rcu_ptr, lock) … /** * tipc_aead_key_validate - Validate a AEAD user key * @ukey: pointer to user key data * @info: netlink info pointer */ int tipc_aead_key_validate(struct tipc_aead_key *ukey, struct genl_info *info) { … } /** * tipc_aead_key_generate - Generate new session key * @skey: input/output key with new content * * Return: 0 in case of success, otherwise < 0 */ static int tipc_aead_key_generate(struct tipc_aead_key *skey) { … } static struct tipc_aead *tipc_aead_get(struct tipc_aead __rcu *aead) { … } static inline void tipc_aead_put(struct tipc_aead *aead) { … } /** * tipc_aead_free - Release AEAD key incl. all the TFMs in the list * @rp: rcu head pointer */ static void tipc_aead_free(struct rcu_head *rp) { … } static int tipc_aead_users(struct tipc_aead __rcu *aead) { … } static void tipc_aead_users_inc(struct tipc_aead __rcu *aead, int lim) { … } static void tipc_aead_users_dec(struct tipc_aead __rcu *aead, int lim) { … } static void tipc_aead_users_set(struct tipc_aead __rcu *aead, int val) { … } /** * tipc_aead_tfm_next - Move TFM entry to the next one in list and return it * @aead: the AEAD key pointer */ static struct crypto_aead *tipc_aead_tfm_next(struct tipc_aead *aead) { … } /** * tipc_aead_init - Initiate TIPC AEAD * @aead: returned new TIPC AEAD key handle pointer * @ukey: pointer to user key data * @mode: the key mode * * Allocate a (list of) new cipher transformation (TFM) with the specific user * key data if valid. The number of the allocated TFMs can be set via the sysfs * "net/tipc/max_tfms" first. * Also, all the other AEAD data are also initialized. * * Return: 0 if the initiation is successful, otherwise: < 0 */ static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey, u8 mode) { … } /** * tipc_aead_clone - Clone a TIPC AEAD key * @dst: dest key for the cloning * @src: source key to clone from * * Make a "copy" of the source AEAD key data to the dest, the TFMs list is * common for the keys. * A reference to the source is hold in the "cloned" pointer for the later * freeing purposes. * * Note: this must be done in cluster-key mode only! * Return: 0 in case of success, otherwise < 0 */ static int tipc_aead_clone(struct tipc_aead **dst, struct tipc_aead *src) { … } /** * tipc_aead_mem_alloc - Allocate memory for AEAD request operations * @tfm: cipher handle to be registered with the request * @crypto_ctx_size: size of crypto context for callback * @iv: returned pointer to IV data * @req: returned pointer to AEAD request data * @sg: returned pointer to SG lists * @nsg: number of SG lists to be allocated * * Allocate memory to store the crypto context data, AEAD request, IV and SG * lists, the memory layout is as follows: * crypto_ctx || iv || aead_req || sg[] * * Return: the pointer to the memory areas in case of success, otherwise NULL */ static void *tipc_aead_mem_alloc(struct crypto_aead *tfm, unsigned int crypto_ctx_size, u8 **iv, struct aead_request **req, struct scatterlist **sg, int nsg) { … } /** * tipc_aead_encrypt - Encrypt a message * @aead: TIPC AEAD key for the message encryption * @skb: the input/output skb * @b: TIPC bearer where the message will be delivered after the encryption * @dst: the destination media address * @__dnode: TIPC dest node if "known" * * Return: * * 0 : if the encryption has completed * * -EINPROGRESS/-EBUSY : if a callback will be performed * * < 0 : the encryption has failed */ static int tipc_aead_encrypt(struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode) { … } static void tipc_aead_encrypt_done(void *data, int err) { … } /** * tipc_aead_decrypt - Decrypt an encrypted message * @net: struct net * @aead: TIPC AEAD for the message decryption * @skb: the input/output skb * @b: TIPC bearer where the message has been received * * Return: * * 0 : if the decryption has completed * * -EINPROGRESS/-EBUSY : if a callback will be performed * * < 0 : the decryption has failed */ static int tipc_aead_decrypt(struct net *net, struct tipc_aead *aead, struct sk_buff *skb, struct tipc_bearer *b) { … } static void tipc_aead_decrypt_done(void *data, int err) { … } static inline int tipc_ehdr_size(struct tipc_ehdr *ehdr) { … } /** * tipc_ehdr_validate - Validate an encryption message * @skb: the message buffer * * Return: "true" if this is a valid encryption message, otherwise "false" */ bool tipc_ehdr_validate(struct sk_buff *skb) { … } /** * tipc_ehdr_build - Build TIPC encryption message header * @net: struct net * @aead: TX AEAD key to be used for the message encryption * @tx_key: key id used for the message encryption * @skb: input/output message skb * @__rx: RX crypto handle if dest is "known" * * Return: the header size if the building is successful, otherwise < 0 */ static int tipc_ehdr_build(struct net *net, struct tipc_aead *aead, u8 tx_key, struct sk_buff *skb, struct tipc_crypto *__rx) { … } static inline void tipc_crypto_key_set_state(struct tipc_crypto *c, u8 new_passive, u8 new_active, u8 new_pending) { … } /** * tipc_crypto_key_init - Initiate a new user / AEAD key * @c: TIPC crypto to which new key is attached * @ukey: the user key * @mode: the key mode (CLUSTER_KEY or PER_NODE_KEY) * @master_key: specify this is a cluster master key * * A new TIPC AEAD key will be allocated and initiated with the specified user * key, then attached to the TIPC crypto. * * Return: new key id in case of success, otherwise: < 0 */ int tipc_crypto_key_init(struct tipc_crypto *c, struct tipc_aead_key *ukey, u8 mode, bool master_key) { … } /** * tipc_crypto_key_attach - Attach a new AEAD key to TIPC crypto * @c: TIPC crypto to which the new AEAD key is attached * @aead: the new AEAD key pointer * @pos: desired slot in the crypto key array, = 0 if any! * @master_key: specify this is a cluster master key * * Return: new key id in case of success, otherwise: -EBUSY */ static int tipc_crypto_key_attach(struct tipc_crypto *c, struct tipc_aead *aead, u8 pos, bool master_key) { … } void tipc_crypto_key_flush(struct tipc_crypto *c) { … } /** * tipc_crypto_key_try_align - Align RX keys if possible * @rx: RX crypto handle * @new_pending: new pending slot if aligned (= TX key from peer) * * Peer has used an unknown key slot, this only happens when peer has left and * rejoned, or we are newcomer. * That means, there must be no active key but a pending key at unaligned slot. * If so, we try to move the pending key to the new slot. * Note: A potential passive key can exist, it will be shifted correspondingly! * * Return: "true" if key is successfully aligned, otherwise "false" */ static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending) { … } /** * tipc_crypto_key_pick_tx - Pick one TX key for message decryption * @tx: TX crypto handle * @rx: RX crypto handle (can be NULL) * @skb: the message skb which will be decrypted later * @tx_key: peer TX key id * * This function looks up the existing TX keys and pick one which is suitable * for the message decryption, that must be a cluster key and not used before * on the same message (i.e. recursive). * * Return: the TX AEAD key handle in case of success, otherwise NULL */ static struct tipc_aead *tipc_crypto_key_pick_tx(struct tipc_crypto *tx, struct tipc_crypto *rx, struct sk_buff *skb, u8 tx_key) { … } /** * tipc_crypto_key_synch: Synch own key data according to peer key status * @rx: RX crypto handle * @skb: TIPCv2 message buffer (incl. the ehdr from peer) * * This function updates the peer node related data as the peer RX active key * has changed, so the number of TX keys' users on this node are increased and * decreased correspondingly. * * It also considers if peer has no key, then we need to make own master key * (if any) taking over i.e. starting grace period and also trigger key * distributing process. * * The "per-peer" sndnxt is also reset when the peer key has switched. */ static void tipc_crypto_key_synch(struct tipc_crypto *rx, struct sk_buff *skb) { … } static int tipc_crypto_key_revoke(struct net *net, u8 tx_key) { … } 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) { … } static inline void tipc_crypto_clone_msg(struct net *net, struct sk_buff *_skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode, u8 type) { … } /** * tipc_crypto_xmit - Build & encrypt TIPC message for xmit * @net: struct net * @skb: input/output message skb pointer * @b: bearer used for xmit later * @dst: destination media address * @__dnode: destination node for reference if any * * First, build an encryption message header on the top of the message, then * encrypt the original TIPC message by using the pending, master or active * key with this preference order. * If the encryption is successful, the encrypted skb is returned directly or * via the callback. * Otherwise, the skb is freed! * * Return: * * 0 : the encryption has succeeded (or no encryption) * * -EINPROGRESS/-EBUSY : the encryption is ongoing, a callback will be made * * -ENOKEK : the encryption has failed due to no key * * -EKEYREVOKED : the encryption has failed due to key revoked * * -ENOMEM : the encryption has failed due to no memory * * < 0 : the encryption has failed due to other reasons */ int tipc_crypto_xmit(struct net *net, struct sk_buff **skb, struct tipc_bearer *b, struct tipc_media_addr *dst, struct tipc_node *__dnode) { … } /** * tipc_crypto_rcv - Decrypt an encrypted TIPC message from peer * @net: struct net * @rx: RX crypto handle * @skb: input/output message skb pointer * @b: bearer where the message has been received * * If the decryption is successful, the decrypted skb is returned directly or * as the callback, the encryption header and auth tag will be trimed out * before forwarding to tipc_rcv() via the tipc_crypto_rcv_complete(). * Otherwise, the skb will be freed! * Note: RX key(s) can be re-aligned, or in case of no key suitable, TX * cluster key(s) can be taken for decryption (- recursive). * * Return: * * 0 : the decryption has successfully completed * * -EINPROGRESS/-EBUSY : the decryption is ongoing, a callback will be made * * -ENOKEY : the decryption has failed due to no key * * -EBADMSG : the decryption has failed due to bad message * * -ENOMEM : the decryption has failed due to no memory * * < 0 : the decryption has failed due to other reasons */ int tipc_crypto_rcv(struct net *net, struct tipc_crypto *rx, struct sk_buff **skb, struct tipc_bearer *b) { … } static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead, struct tipc_bearer *b, struct sk_buff **skb, int err) { … } static void tipc_crypto_do_cmd(struct net *net, int cmd) { … } static char *tipc_crypto_key_dump(struct tipc_crypto *c, char *buf) { … } static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new, char *buf) { … } /** * tipc_crypto_msg_rcv - Common 'MSG_CRYPTO' processing point * @net: the struct net * @skb: the receiving message buffer */ void tipc_crypto_msg_rcv(struct net *net, struct sk_buff *skb) { … } /** * tipc_crypto_key_distr - Distribute a TX key * @tx: the TX crypto * @key: the key's index * @dest: the destination tipc node, = NULL if distributing to all nodes * * Return: 0 in case of success, otherwise < 0 */ int tipc_crypto_key_distr(struct tipc_crypto *tx, u8 key, struct tipc_node *dest) { … } /** * tipc_crypto_key_xmit - Send a session key * @net: the struct net * @skey: the session key to be sent * @gen: the key's generation * @mode: the key's mode * @dnode: the destination node address, = 0 if broadcasting to all nodes * * The session key 'skey' is packed in a TIPC v2 'MSG_CRYPTO/KEY_DISTR_MSG' * as its data section, then xmit-ed through the uc/bc link. * * Return: 0 in case of success, otherwise < 0 */ static int tipc_crypto_key_xmit(struct net *net, struct tipc_aead_key *skey, u16 gen, u8 mode, u32 dnode) { … } /** * tipc_crypto_key_rcv - Receive a session key * @rx: the RX crypto * @hdr: the TIPC v2 message incl. the receiving session key in its data * * This function retrieves the session key in the message from peer, then * schedules a RX work to attach the key to the corresponding RX crypto. * * Return: "true" if the key has been scheduled for attaching, otherwise * "false". */ static bool tipc_crypto_key_rcv(struct tipc_crypto *rx, struct tipc_msg *hdr) { … } /** * tipc_crypto_work_rx - Scheduled RX works handler * @work: the struct RX work * * The function processes the previous scheduled works i.e. distributing TX key * or attaching a received session key on RX crypto. */ static void tipc_crypto_work_rx(struct work_struct *work) { … } /** * tipc_crypto_rekeying_sched - (Re)schedule rekeying w/o new interval * @tx: TX crypto * @changed: if the rekeying needs to be rescheduled with new interval * @new_intv: new rekeying interval (when "changed" = true) */ void tipc_crypto_rekeying_sched(struct tipc_crypto *tx, bool changed, u32 new_intv) { … } /** * tipc_crypto_work_tx - Scheduled TX works handler * @work: the struct TX work * * The function processes the previous scheduled work, i.e. key rekeying, by * generating a new session key based on current one, then attaching it to the * TX crypto and finally distributing it to peers. It also re-schedules the * rekeying if needed. */ static void tipc_crypto_work_tx(struct work_struct *work) { … }
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