[v2,10/35] net/tcp: Calculate TCP-AO traffic keys

Message ID	20220923201319.493208-11-dima@arista.com (mailing list archive)
State	Changes Requested
Delegated to:	Netdev Maintainers
Headers	show Return-Path: <netdev-owner@kernel.org> From: Dmitry Safonov <dima@arista.com> To: linux-kernel@vger.kernel.org, David Ahern <dsahern@kernel.org>, Eric Dumazet <edumazet@google.com> Cc: Dmitry Safonov <dima@arista.com>, Andy Lutomirski <luto@amacapital.net>, Ard Biesheuvel <ardb@kernel.org>, Bob Gilligan <gilligan@arista.com>, Dan Carpenter <dan.carpenter@oracle.com>, "David S. Miller" <davem@davemloft.net>, Dmitry Safonov <0x7f454c46@gmail.com>, Eric Biggers <ebiggers@kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, Francesco Ruggeri <fruggeri@arista.com>, Herbert Xu <herbert@gondor.apana.org.au>, Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>, Ivan Delalande <colona@arista.com>, Jakub Kicinski <kuba@kernel.org>, Leonard Crestez <cdleonard@gmail.com>, Paolo Abeni <pabeni@redhat.com>, Salam Noureddine <noureddine@arista.com>, Shuah Khan <shuah@kernel.org>, netdev@vger.kernel.org, linux-crypto@vger.kernel.org Subject: [PATCH v2 10/35] net/tcp: Calculate TCP-AO traffic keys Date: Fri, 23 Sep 2022 21:12:54 +0100 Message-Id: <20220923201319.493208-11-dima@arista.com> In-Reply-To: <20220923201319.493208-1-dima@arista.com> References: <20220923201319.493208-1-dima@arista.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	net/tcp: Add TCP-AO support \| expand [v2,00/35] net/tcp: Add TCP-AO support [v2,01/35] crypto: Introduce crypto_pool [v2,02/35] crypto_pool: Add crypto_pool_reserve_scratch() [v2,03/35] net/tcp: Separate tcp_md5sig_info allocation into tcp_md5sig_info_add() [v2,04/35] net/tcp: Disable TCP-MD5 static key on tcp_md5sig_info destruction [v2,05/35] net/tcp: Use crypto_pool for TCP-MD5 [v2,06/35] net/ipv6: sr: Switch to using crypto_pool [v2,07/35] tcp: Add TCP-AO config and structures [v2,08/35] net/tcp: Introduce TCP_AO setsockopt()s [v2,09/35] net/tcp: Prevent TCP-MD5 with TCP-AO being set [v2,10/35] net/tcp: Calculate TCP-AO traffic keys [v2,11/35] net/tcp: Add TCP-AO sign to outgoing packets [v2,12/35] net/tcp: Add tcp_parse_auth_options() [v2,13/35] net/tcp: Add AO sign to RST packets [v2,14/35] net/tcp: Add TCP-AO sign to twsk [v2,15/35] net/tcp: Wire TCP-AO to request sockets [v2,16/35] net/tcp: Sign SYN-ACK segments with TCP-AO [v2,17/35] net/tcp: Verify inbound TCP-AO signed segments [v2,18/35] net/tcp: Add TCP-AO segments counters [v2,19/35] net/tcp: Add TCP-AO SNE support [v2,20/35] net/tcp: Add tcp_hash_fail() ratelimited logs [v2,21/35] net/tcp: Ignore specific ICMPs for TCP-AO connections [v2,22/35] net/tcp: Add option for TCP-AO to (not) hash header [v2,23/35] net/tcp: Add getsockopt(TCP_AO_GET) [v2,24/35] net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs) [v2,25/35] selftests/net: Add TCP-AO library [v2,26/35] selftests/net: Verify that TCP-AO complies with ignoring ICMPs [v2,27/35] selftest/net: Add TCP-AO ICMPs accept test [v2,28/35] selftest/tcp-ao: Add a test for MKT matching [v2,29/35] selftest/tcp-ao: Add test for TCP-AO add setsockopt() command [v2,30/35] selftests/tcp-ao: Add TCP-AO + TCP-MD5 + no sign listen socket tests [v2,31/35] selftests/aolib: Add test/benchmark for removing MKTs [v2,32/35] selftests/nettest: Remove client_pw [v2,33/35] selftest/nettest: Rename md5_prefix* => auth_prefix* [v2,34/35] selftests/nettest: Add TCP-AO support [v2,35/35] selftests/fcnal-test.sh: Add TCP-AO tests

Context	Check	Description
netdev/tree_selection	success	Guessing tree name failed - patch did not apply, async

diff --git a/include/net/tcp.h b/include/net/tcp.h index 9c71f48cc99c..e140ae4fe653 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2078,6 +2078,11 @@ struct tcp_sock_af_ops { struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid); + int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, + u8 *key, + const struct sock *sk, + __be32 sisn, __be32 disn, + bool send); #endif }; diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index c550f1a6f5fd..f83a4d09a4ce 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -88,9 +88,33 @@ struct tcp_ao_info { }; #ifdef CONFIG_TCP_AO +/* TCP-AO structures and functions */ + +struct tcp4_ao_context { + __be32 saddr; + __be32 daddr; + __be16 sport; + __be16 dport; + __be32 sisn; + __be32 disn; +}; + +struct tcp6_ao_context { + struct in6_addr saddr; + struct in6_addr daddr; + __be16 sport; + __be16 dport; + __be32 sisn; + __be32 disn; +}; + int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, sockptr_t optval, int optlen); +int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, + unsigned int len); void tcp_ao_destroy_sock(struct sock *sk); +int tcp_ao_cache_traffic_keys(const struct sock *sk, struct tcp_ao_info *ao, + struct tcp_ao_key *ao_key); struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr, int family, int sndid, int rcvid, u16 port); @@ -98,13 +122,23 @@ struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen); struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid); +int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, + __be32 sisn, __be32 disn, bool send); /* ipv6 specific functions */ +int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, __be32 sisn, + __be32 disn, bool send); struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid); int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); -#else +void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb); +void tcp_ao_connect_init(struct sock *sk); + +#else /* CONFIG_TCP_AO */ + static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr, int family, int sndid, int rcvid, u16 port) @@ -115,6 +149,14 @@ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, static inline void tcp_ao_destroy_sock(struct sock *sk) { } + +static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb) +{ +} + +static inline void tcp_ao_connect_init(struct sock *sk) +{ +} #endif #endif /* _TCP_AO_H */ diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index 2e90b5a7b941..841f5db7393b 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -16,6 +16,42 @@ #include <net/tcp.h> #include <net/ipv6.h> +int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx, + unsigned int len) +{ + struct crypto_pool_ahash hp; + struct scatterlist sg; + int ret; + + if (crypto_pool_get(mkt->crypto_pool_id, (struct crypto_pool *)&hp)) + goto clear_hash_noput; + + if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), + mkt->key, mkt->keylen)) + goto clear_hash; + + ret = crypto_ahash_init(hp.req); + if (ret) + goto clear_hash; + + sg_init_one(&sg, ctx, len); + ahash_request_set_crypt(hp.req, &sg, key, len); + crypto_ahash_update(hp.req); + + /* TODO: Revisit on how to get different output length */ + ret = crypto_ahash_final(hp.req); + if (ret) + goto clear_hash; + + crypto_pool_put(); + return 0; +clear_hash: + crypto_pool_put(); +clear_hash_noput: + memset(key, 0, tcp_ao_digest_size(mkt)); + return 1; +} + static struct tcp_ao_key *tcp_ao_do_lookup_rcvid(struct sock *sk, u8 keyid) { struct tcp_sock *tp = tcp_sk(sk); @@ -181,6 +217,47 @@ void tcp_ao_destroy_sock(struct sock *sk) kfree_rcu(ao, rcu); } +/* 4 tuple and ISNs are expected in NBO */ +static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key, + __be32 saddr, __be32 daddr, + __be16 sport, __be16 dport, + __be32 sisn, __be32 disn) +{ + /* See RFC5926 3.1.1 */ + struct kdf_input_block { + u8 counter; + u8 label[6]; + struct tcp4_ao_context ctx; + __be16 outlen; + } __packed tmp; + + tmp.counter = 1; + memcpy(tmp.label, "TCP-AO", 6); + tmp.ctx.saddr = saddr; + tmp.ctx.daddr = daddr; + tmp.ctx.sport = sport; + tmp.ctx.dport = dport; + tmp.ctx.sisn = sisn; + tmp.ctx.disn = disn; + tmp.outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */ + + return tcp_ao_calc_traffic_key(mkt, key, &tmp, sizeof(tmp)); +} + +int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, + __be32 sisn, __be32 disn, bool send) +{ + if (send) + return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr, + sk->sk_daddr, htons(sk->sk_num), + sk->sk_dport, sisn, disn); + else + return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr, + sk->sk_rcv_saddr, sk->sk_dport, + htons(sk->sk_num), disn, sisn); +} + struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, int sndid, int rcvid) { @@ -189,6 +266,103 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0); } +int tcp_ao_cache_traffic_keys(const struct sock *sk, struct tcp_ao_info *ao, + struct tcp_ao_key *ao_key) +{ + u8 *traffic_key = snd_other_key(ao_key); + int ret; + + ret = tcp_sk(sk)->af_specific->ao_calc_key_sk(ao_key, traffic_key, sk, + ao->lisn, ao->risn, true); + if (ret) + return ret; + + traffic_key = rcv_other_key(ao_key); + return tcp_sk(sk)->af_specific->ao_calc_key_sk(ao_key, traffic_key, sk, + ao->lisn, ao->risn, + false); +} + +void tcp_ao_connect_init(struct sock *sk) +{ + struct tcp_ao_info *ao_info; + struct tcp_ao_key *key; + struct tcp_sock *tp = tcp_sk(sk); + union tcp_ao_addr *addr; + int family; + + ao_info = rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held(sk)); + if (!ao_info) + return; + + /* Remove all keys that don't match the peer */ + family = sk->sk_family; + if (family == AF_INET) + addr = (union tcp_ao_addr *)&sk->sk_daddr; +#if IS_ENABLED(CONFIG_IPV6) + else if (family == AF_INET6) + addr = (union tcp_ao_addr *)&sk->sk_v6_daddr; +#endif + else + return; + + hlist_for_each_entry_rcu(key, &ao_info->head, node) { + if (tcp_ao_key_cmp(key, addr, key->prefixlen, family, + -1, -1, sk->sk_dport) == 0) + continue; + + if (key == ao_info->current_key) + ao_info->current_key = NULL; + if (key == ao_info->rnext_key) + ao_info->rnext_key = NULL; + hlist_del_rcu(&key->node); + crypto_pool_release(key->crypto_pool_id); + atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc); + kfree_rcu(key, rcu); + } + + key = tp->af_specific->ao_lookup(sk, sk, -1, -1); + if (key) { + /* if current_key or rnext_key were not provided, + * use the first key matching the peer + */ + if (!ao_info->current_key) + ao_info->current_key = key; + if (!ao_info->rnext_key) + ao_info->rnext_key = key; + tp->tcp_header_len += tcp_ao_len(key); + + ao_info->lisn = htonl(tp->write_seq); + ao_info->snd_sne = 0; + ao_info->snd_sne_seq = tp->write_seq; + } else { + WARN_ON_ONCE(1); + rcu_assign_pointer(tp->ao_info, NULL); + kfree(ao_info); + } +} + +void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_ao_info *ao; + struct tcp_ao_key *key; + + ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, + lockdep_sock_is_held(sk)); + if (!ao) + return; + + ao->risn = tcp_hdr(skb)->seq; + + ao->rcv_sne = 0; + ao->rcv_sne_seq = ntohl(tcp_hdr(skb)->seq); + + hlist_for_each_entry_rcu(key, &ao->head, node) { + tcp_ao_cache_traffic_keys(sk, ao, key); + } +} + static int tcp_ao_current_rnext(struct sock *sk, u16 tcpa_flags, u8 tcpa_sndid, u8 tcpa_rcvid) { @@ -681,6 +855,12 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family, if (ret < 0) goto err_free_sock; + /* Change this condition if we allow adding keys in states + * like close_wait, syn_sent or fin_wait... + */ + if (sk->sk_state == TCP_ESTABLISHED) + tcp_ao_cache_traffic_keys(sk, ao_info, key); + tcp_ao_link_mkt(ao_info, key); if (first) { sk_gso_disable(sk); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bc2ea12221f9..ad9ced317768 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6051,6 +6051,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb) struct tcp_sock *tp = tcp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); + tcp_ao_finish_connect(sk, skb); tcp_set_state(sk, TCP_ESTABLISHED); icsk->icsk_ack.lrcvtime = tcp_jiffies32; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f3d183be2595..e05bdad361c3 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2251,6 +2251,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { #ifdef CONFIG_TCP_AO .ao_lookup = tcp_v4_ao_lookup, .ao_parse = tcp_v4_parse_ao, + .ao_calc_key_sk = tcp_v4_ao_calc_key_sk, #endif }; #endif diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 4b9ffd6b901d..23069a34dd47 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3661,6 +3661,7 @@ static void tcp_connect_init(struct sock *sk) if (tp->af_specific->md5_lookup(sk, sk)) tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED; #endif + tcp_ao_connect_init(sk); /* If user gave his TCP_MAXSEG, record it to clamp */ if (tp->rx_opt.user_mss) diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c index 221b8adb4f73..888ee6242334 100644 --- a/net/ipv6/tcp_ao.c +++ b/net/ipv6/tcp_ao.c @@ -13,6 +13,46 @@ #include <net/tcp.h> #include <net/ipv6.h> +int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key, + const struct in6_addr *saddr, + const struct in6_addr *daddr, + __be16 sport, __be16 dport, + __be32 sisn, __be32 disn) +{ + struct kdf_input_block { + u8 counter; + u8 label[6]; + struct tcp6_ao_context ctx; + __be16 outlen; + } __packed tmp; + + tmp.counter = 1; + memcpy(tmp.label, "TCP-AO", 6); + tmp.ctx.saddr = *saddr; + tmp.ctx.daddr = *daddr; + tmp.ctx.sport = sport; + tmp.ctx.dport = dport; + tmp.ctx.sisn = sisn; + tmp.ctx.disn = disn; + tmp.outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */ + + return tcp_ao_calc_traffic_key(mkt, key, &tmp, sizeof(tmp)); +} + +int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, __be32 sisn, + __be32 disn, bool send) +{ + if (send) + return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_rcv_saddr, + &sk->sk_v6_daddr, htons(sk->sk_num), + sk->sk_dport, sisn, disn); + else + return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_daddr, + &sk->sk_v6_rcv_saddr, sk->sk_dport, + htons(sk->sk_num), disn, sisn); +} + struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk, const struct in6_addr *addr, int sndid, int rcvid) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index f5780a3fbd1b..c6d2389030f2 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1905,6 +1905,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { #ifdef CONFIG_TCP_AO .ao_lookup = tcp_v6_ao_lookup, .ao_parse = tcp_v6_parse_ao, + .ao_calc_key_sk = tcp_v6_ao_calc_key_sk, #endif }; #endif

[v2,10/35] net/tcp: Calculate TCP-AO traffic keys

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