From: Leonard Crestez <cdleonard@gmail.com>
To: David Ahern <dsahern@kernel.org>, Shuah Khan <shuah@kernel.org>,
Dmitry Safonov <0x7f454c46@gmail.com>,
Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Herbert Xu <herbert@gondor.apana.org.au>,
Kuniyuki Iwashima <kuniyu@amazon.co.jp>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Jakub Kicinski <kuba@kernel.org>,
Yuchung Cheng <ycheng@google.com>,
Francesco Ruggeri <fruggeri@arista.com>,
Mat Martineau <mathew.j.martineau@linux.intel.com>,
Christoph Paasch <cpaasch@apple.com>,
Ivan Delalande <colona@arista.com>,
Priyaranjan Jha <priyarjha@google.com>,
netdev@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 13/25] tcp: authopt: Add support for signing skb-less replies
Date: Mon, 1 Nov 2021 18:34:48 +0200 [thread overview]
Message-ID: <23d0934b85fa00e8f2aa8ebb1af3005fbed5b347.1635784253.git.cdleonard@gmail.com> (raw)
In-Reply-To: <cover.1635784253.git.cdleonard@gmail.com>
This is required because tcp ipv4 sometimes sends replies without
allocating a full skb that can be signed by tcp authopt.
Handle this with additional code in tcp authopt.
Signed-off-by: Leonard Crestez <cdleonard@gmail.com>
---
include/net/tcp_authopt.h | 7 ++
net/ipv4/tcp_authopt.c | 147 ++++++++++++++++++++++++++++++++++++++
2 files changed, 154 insertions(+)
diff --git a/include/net/tcp_authopt.h b/include/net/tcp_authopt.h
index 7360bda20f97..ae7d6a1eab8d 100644
--- a/include/net/tcp_authopt.h
+++ b/include/net/tcp_authopt.h
@@ -101,10 +101,17 @@ static inline struct tcp_authopt_key_info *tcp_authopt_select_key(
int tcp_authopt_hash(
char *hash_location,
struct tcp_authopt_key_info *key,
struct tcp_authopt_info *info,
struct sock *sk, struct sk_buff *skb);
+int tcp_v4_authopt_hash_reply(
+ char *hash_location,
+ struct tcp_authopt_info *info,
+ struct tcp_authopt_key_info *key,
+ __be32 saddr,
+ __be32 daddr,
+ struct tcphdr *th);
int __tcp_authopt_openreq(struct sock *newsk, const struct sock *oldsk, struct request_sock *req);
static inline int tcp_authopt_openreq(
struct sock *newsk,
const struct sock *oldsk,
struct request_sock *req)
diff --git a/net/ipv4/tcp_authopt.c b/net/ipv4/tcp_authopt.c
index c9d201d8f7a7..aef63e35b56f 100644
--- a/net/ipv4/tcp_authopt.c
+++ b/net/ipv4/tcp_authopt.c
@@ -799,10 +799,74 @@ static int tcp_authopt_get_traffic_key(struct sock *sk,
out:
tcp_authopt_put_kdf_shash(key, kdf_tfm);
return err;
}
+struct tcp_v4_authopt_context_data {
+ __be32 saddr;
+ __be32 daddr;
+ __be16 sport;
+ __be16 dport;
+ __be32 sisn;
+ __be32 disn;
+ __be16 digestbits;
+} __packed;
+
+static int tcp_v4_authopt_get_traffic_key_noskb(struct tcp_authopt_key_info *key,
+ __be32 saddr,
+ __be32 daddr,
+ __be16 sport,
+ __be16 dport,
+ __be32 sisn,
+ __be32 disn,
+ u8 *traffic_key)
+{
+ int err;
+ struct crypto_shash *kdf_tfm;
+ SHASH_DESC_ON_STACK(desc, kdf_tfm);
+ struct tcp_v4_authopt_context_data data;
+
+ BUILD_BUG_ON(sizeof(data) != 22);
+
+ kdf_tfm = tcp_authopt_get_kdf_shash(key);
+ if (IS_ERR(kdf_tfm))
+ return PTR_ERR(kdf_tfm);
+
+ err = tcp_authopt_setkey(kdf_tfm, key);
+ if (err)
+ goto out;
+
+ desc->tfm = kdf_tfm;
+ err = crypto_shash_init(desc);
+ if (err)
+ goto out;
+
+ // RFC5926 section 3.1.1.1
+ // Separate to keep alignment semi-sane
+ err = crypto_shash_update(desc, "\x01TCP-AO", 7);
+ if (err)
+ return err;
+ data.saddr = saddr;
+ data.daddr = daddr;
+ data.sport = sport;
+ data.dport = dport;
+ data.sisn = sisn;
+ data.disn = disn;
+ data.digestbits = htons(crypto_shash_digestsize(desc->tfm) * 8);
+
+ err = crypto_shash_update(desc, (u8 *)&data, sizeof(data));
+ if (err)
+ goto out;
+ err = crypto_shash_final(desc, traffic_key);
+ if (err)
+ goto out;
+
+out:
+ tcp_authopt_put_kdf_shash(key, kdf_tfm);
+ return err;
+}
+
static int crypto_shash_update_zero(struct shash_desc *desc, int len)
{
u8 zero = 0;
int i, err;
@@ -1205,10 +1269,93 @@ int tcp_authopt_hash(char *hash_location,
memset(hash_location, 0, TCP_AUTHOPT_MACLEN);
return err;
}
EXPORT_SYMBOL(tcp_authopt_hash);
+/**
+ * tcp_v4_authopt_hash_reply - Hash tcp+ipv4 header without SKB
+ *
+ * @hash_location: output buffer
+ * @info: sending socket's tcp_authopt_info
+ * @key: signing key, from tcp_authopt_select_key.
+ * @saddr: source address
+ * @daddr: destination address
+ * @th: Pointer to TCP header and options
+ */
+int tcp_v4_authopt_hash_reply(char *hash_location,
+ struct tcp_authopt_info *info,
+ struct tcp_authopt_key_info *key,
+ __be32 saddr,
+ __be32 daddr,
+ struct tcphdr *th)
+{
+ struct crypto_shash *mac_tfm;
+ u8 macbuf[TCP_AUTHOPT_MAXMACBUF];
+ u8 traffic_key[TCP_AUTHOPT_MAX_TRAFFIC_KEY_LEN];
+ SHASH_DESC_ON_STACK(desc, tfm);
+ __be32 sne = 0;
+ int err;
+
+ /* Call special code path for computing traffic key without skb
+ * This can be called from tcp_v4_reqsk_send_ack so caching would be
+ * difficult here.
+ */
+ err = tcp_v4_authopt_get_traffic_key_noskb(key, saddr, daddr,
+ th->source, th->dest,
+ htonl(info->src_isn), htonl(info->dst_isn),
+ traffic_key);
+ if (err)
+ goto out_err_traffic_key;
+
+ /* Init mac shash */
+ mac_tfm = tcp_authopt_get_mac_shash(key);
+ if (IS_ERR(mac_tfm))
+ return PTR_ERR(mac_tfm);
+ err = crypto_shash_setkey(mac_tfm, traffic_key, key->alg->traffic_key_len);
+ if (err)
+ goto out_err;
+
+ desc->tfm = mac_tfm;
+ err = crypto_shash_init(desc);
+ if (err)
+ return err;
+
+ err = crypto_shash_update(desc, (u8 *)&sne, 4);
+ if (err)
+ return err;
+
+ err = tcp_authopt_hash_tcp4_pseudoheader(desc, saddr, daddr, th->doff * 4);
+ if (err)
+ return err;
+
+ // TCP header with checksum set to zero. Caller ensures this.
+ if (WARN_ON_ONCE(th->check != 0))
+ goto out_err;
+ err = crypto_shash_update(desc, (u8 *)th, sizeof(*th));
+ if (err)
+ goto out_err;
+
+ // TCP options
+ err = tcp_authopt_hash_opts(desc, th, !(key->flags & TCP_AUTHOPT_KEY_EXCLUDE_OPTS));
+ if (err)
+ goto out_err;
+
+ err = crypto_shash_final(desc, macbuf);
+ if (err)
+ goto out_err;
+ memcpy(hash_location, macbuf, TCP_AUTHOPT_MACLEN);
+
+ tcp_authopt_put_mac_shash(key, mac_tfm);
+ return 0;
+
+out_err:
+ tcp_authopt_put_mac_shash(key, mac_tfm);
+out_err_traffic_key:
+ memset(hash_location, 0, TCP_AUTHOPT_MACLEN);
+ return err;
+}
+
static struct tcp_authopt_key_info *tcp_authopt_lookup_recv(struct sock *sk,
struct sk_buff *skb,
struct tcp_authopt_info *info,
int recv_id)
{
--
2.25.1
next prev parent reply other threads:[~2021-11-01 16:36 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 16:34 [PATCH v2] tcp: Initial support for RFC5925 auth option Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 01/25] tcp: authopt: Initial support and key management Leonard Crestez
2021-11-03 2:29 ` David Ahern
2021-11-05 12:10 ` Leonard Crestez
2021-11-05 1:22 ` Dmitry Safonov
2021-11-05 7:04 ` Leonard Crestez
2021-11-05 14:50 ` Dmitry Safonov
2021-11-05 18:00 ` Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 02/25] docs: Add user documentation for tcp_authopt Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 03/25] selftests: Initial tcp_authopt test module Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 04/25] selftests: tcp_authopt: Initial sockopt manipulation Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 05/25] tcp: authopt: Add crypto initialization Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 06/25] tcp: authopt: Compute packet signatures Leonard Crestez
2021-11-05 1:53 ` Dmitry Safonov
2021-11-05 6:39 ` Leonard Crestez
2021-11-05 2:08 ` Dmitry Safonov
2021-11-05 6:09 ` Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 07/25] tcp: Use BIT() for OPTION_* constants Leonard Crestez
2021-11-03 2:31 ` David Ahern
2021-11-03 22:19 ` Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 08/25] tcp: authopt: Hook into tcp core Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 09/25] tcp: authopt: Disable via sysctl by default Leonard Crestez
2021-11-03 2:39 ` David Ahern
2021-11-05 8:50 ` Leonard Crestez
2021-11-05 1:46 ` Dmitry Safonov
2021-11-01 16:34 ` [PATCH v2 10/25] selftests: tcp_authopt: Test key address binding Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 11/25] tcp: authopt: Implement Sequence Number Extension Leonard Crestez
2021-11-01 19:22 ` Francesco Ruggeri
2021-11-02 10:03 ` Leonard Crestez
2021-11-02 19:21 ` Francesco Ruggeri
2021-11-03 22:01 ` Leonard Crestez
2021-11-01 20:54 ` Eric Dumazet
2021-11-02 9:50 ` Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 12/25] tcp: ipv6: Add AO signing for tcp_v6_send_response Leonard Crestez
2021-11-03 2:44 ` David Ahern
2021-11-03 22:09 ` Leonard Crestez
2021-11-01 16:34 ` Leonard Crestez [this message]
2021-11-01 16:34 ` [PATCH v2 14/25] tcp: ipv4: Add AO signing for skb-less replies Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 15/25] selftests: tcp_authopt: Implement SNE in python Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 16/25] selftests: tcp_authopt: Add scapy-based packet signing code Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 17/25] selftests: tcp_authopt: Add packet-level tests Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 18/25] selftests: tcp_authopt: Initial sne test Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 19/25] tcp: authopt: Add key selection controls Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 20/25] selftests: tcp_authopt: Add tests for rollover Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 21/25] tcp: authopt: Add initial l3index support Leonard Crestez
2021-11-03 3:06 ` David Ahern
2021-11-05 12:26 ` Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 22/25] selftests: tcp_authopt: Initial tests for l3mdev handling Leonard Crestez
2021-11-01 16:34 ` [PATCH v2 23/25] selftests: nettest: Rename md5_prefix to key_addr_prefix Leonard Crestez
2021-11-03 3:08 ` David Ahern
2021-11-01 16:34 ` [PATCH v2 24/25] selftests: nettest: Initial tcp_authopt support Leonard Crestez
2021-11-03 3:09 ` David Ahern
2021-11-01 16:35 ` [PATCH v2 25/25] selftests: net/fcnal: " Leonard Crestez
2021-11-03 3:18 ` [PATCH v2] tcp: Initial support for RFC5925 auth option David Ahern
2021-11-03 22:22 ` Leonard Crestez
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