From patchwork Thu Dec 23 15:40:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 527764 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9263C43217 for ; Thu, 23 Dec 2021 15:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349215AbhLWPlS (ORCPT ); Thu, 23 Dec 2021 10:41:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349012AbhLWPk5 (ORCPT ); Thu, 23 Dec 2021 10:40:57 -0500 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4B2FC0617A1; Thu, 23 Dec 2021 07:40:55 -0800 (PST) Received: by mail-ed1-x534.google.com with SMTP id j21so22920883edt.9; Thu, 23 Dec 2021 07:40:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QbGn+12SmWm9XZSkxI+H9M/uSYS0f/ErlL5WlEkQuTY=; b=adsLgII17gxA8WfT3MHq0YtX5IWhIk3It+CB9roewYAaJ6YTFssvKYEv6jG/TFZ1Pi GBxoZZRLm+DQNLG0tvZpG/A8vbpbSIn/o2MrOBVNm6zkbtcSLzLI23dGPRWponHAuzJI 6MYDCpqMccmhE/PVRunZrqFOMHrAtBwhQfr5XW1SyWf03tSkx0Nl750+Yf17VG8r/ufb CRKXf4NnWC6X2ioHI0iEYG0OFuDSODjT0muOUySGPh2nGYBN9kC0X0kA4fDmDaUHka7G fYN26/RdBGNhQvSX02kNZiYDqJwhNJma6wB7U2pM7uzt875V5vav2XuSj+1apU4NRaR0 zo/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QbGn+12SmWm9XZSkxI+H9M/uSYS0f/ErlL5WlEkQuTY=; b=70xeKX6JwahQNuFKBu0stotyH9GO3Ek6BRkNRzv5933BXb03jwsfrSMFlAygm7PLeF bQvPBgM12Fb+ew3ZlH/n4JbpOVa5oNCBd3ADHGYRb+vtZfjxv1tN3qHDZFud1nLff+Vw cv0L1ay40btgrxb0a5ld9+vpSYX/nJAlv2Xpbcq9aH0ySDWPusmfk7WXzV1TUEEOJtoX lZFlYHTJIEDp3pe4v1ZIkkPSOoLQtsoidbW8qPu1+uIag5JZuTnmySal1ZCTBWXwAd1U MAzfg8m1OfHri8XsDXRmx0Hksh8o6eqJASeeLxJ0/9q4mW6QmZvCZz1Vo+za1Uzi8E/G P3tA== X-Gm-Message-State: AOAM531YJZTdmBOWNPGWlV0xEoUgjQfgbjn9pbtF5Pk2H6NnP9hSUhN8 DH2XOL5k1SVyWucuPVY9RHo= X-Google-Smtp-Source: ABdhPJyLwLWPO0ernvKv6pby6H04cOtGTdeAie5twflvYJL6MdBAbl7XJ6oS5pS8vUi4NUICM9VUwg== X-Received: by 2002:a17:907:2be9:: with SMTP id gv41mr2438145ejc.468.1640274054324; Thu, 23 Dec 2021 07:40:54 -0800 (PST) Received: from ponky.lan ([2a04:241e:501:3870:7c02:dfc6:b554:ab10]) by smtp.gmail.com with ESMTPSA id bx6sm2088617edb.78.2021.12.23.07.40.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Dec 2021 07:40:53 -0800 (PST) From: Leonard Crestez To: David Ahern , Eric Dumazet , Philip Paeps , Dmitry Safonov <0x7f454c46@gmail.com> Cc: Shuah Khan , "David S. Miller" , Herbert Xu , Kuniyuki Iwashima , Hideaki YOSHIFUJI , Jakub Kicinski , Yuchung Cheng , Francesco Ruggeri , Mat Martineau , Christoph Paasch , Ivan Delalande , Priyaranjan Jha , netdev@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 10/19] tcp: authopt: Add support for signing skb-less replies Date: Thu, 23 Dec 2021 17:40:05 +0200 Message-Id: <95cd9a5582e868083d742548d35f39eb6584211b.1640273966.git.cdleonard@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org 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 --- include/net/tcp_authopt.h | 7 ++ net/ipv4/tcp_authopt.c | 144 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 151 insertions(+) diff --git a/include/net/tcp_authopt.h b/include/net/tcp_authopt.h index 6e9b5ca22f62..9ee5165388b1 100644 --- a/include/net/tcp_authopt.h +++ b/include/net/tcp_authopt.h @@ -115,10 +115,17 @@ 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 dbe92c87af5a..6803fc39f9b6 100644 --- a/net/ipv4/tcp_authopt.c +++ b/net/ipv4/tcp_authopt.c @@ -922,10 +922,72 @@ static int tcp_authopt_get_traffic_key(struct sock *sk, out: tcp_authopt_put_kdf_pool(key, pool); 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 tcp_authopt_alg_pool *pool; + struct tcp_v4_authopt_context_data data; + + BUILD_BUG_ON(sizeof(data) != 22); + + pool = tcp_authopt_get_kdf_pool(key); + if (IS_ERR(pool)) + return PTR_ERR(pool); + + err = tcp_authopt_setkey(pool, key); + if (err) + goto out; + err = crypto_ahash_init(pool->req); + if (err) + goto out; + + // RFC5926 section 3.1.1.1 + // Separate to keep alignment semi-sane + err = crypto_ahash_buf(pool->req, "\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_ahash_digestsize(pool->tfm) * 8); + + err = crypto_ahash_buf(pool->req, (u8 *)&data, sizeof(data)); + if (err) + goto out; + ahash_request_set_crypt(pool->req, NULL, traffic_key, 0); + err = crypto_ahash_final(pool->req); + if (err) + goto out; + +out: + tcp_authopt_put_kdf_pool(key, pool); + return err; +} + static int crypto_ahash_buf_zero(struct ahash_request *req, int len) { u8 zeros[TCP_AUTHOPT_MACLEN] = {0}; int buflen, err; @@ -1185,10 +1247,92 @@ 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 tcp_authopt_alg_pool *pool; + u8 macbuf[TCP_AUTHOPT_MAXMACBUF]; + u8 traffic_key[TCP_AUTHOPT_MAX_TRAFFIC_KEY_LEN]; + __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 */ + pool = tcp_authopt_get_mac_pool(key); + if (IS_ERR(pool)) + return PTR_ERR(pool); + err = crypto_ahash_setkey(pool->tfm, traffic_key, key->alg->traffic_key_len); + if (err) + goto out_err; + err = crypto_ahash_init(pool->req); + if (err) + return err; + + err = crypto_ahash_buf(pool->req, (u8 *)&sne, 4); + if (err) + return err; + + err = tcp_authopt_hash_tcp4_pseudoheader(pool, 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_ahash_buf(pool->req, (u8 *)th, sizeof(*th)); + if (err) + goto out_err; + + // TCP options + err = tcp_authopt_hash_opts(pool, th, (struct tcphdr_authopt *)(hash_location - 4), + !(key->flags & TCP_AUTHOPT_KEY_EXCLUDE_OPTS)); + if (err) + goto out_err; + + ahash_request_set_crypt(pool->req, NULL, macbuf, 0); + err = crypto_ahash_final(pool->req); + if (err) + goto out_err; + memcpy(hash_location, macbuf, TCP_AUTHOPT_MACLEN); + + tcp_authopt_put_mac_pool(key, pool); + return 0; + +out_err: + tcp_authopt_put_mac_pool(key, pool); +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 netns_tcp_authopt *net, int recv_id, bool *anykey)