From patchwork Mon Sep 5 07:05:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 605413 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 C5C91C6FA8B for ; Mon, 5 Sep 2022 07:07:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237152AbiIEHHh (ORCPT ); Mon, 5 Sep 2022 03:07:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237191AbiIEHGg (ORCPT ); Mon, 5 Sep 2022 03:06:36 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D740F3D586; Mon, 5 Sep 2022 00:06:33 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id cu2so15231574ejb.0; Mon, 05 Sep 2022 00:06:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=di4x9TAxPTC63VUTw6cCZzEo+mtNXmMeptdsWxYJLB8=; b=dxE9JZmQgOSmiA6DHETgX+2/moWT0FeXXbEB+OCCk6Y7wnLHbCnC+Wd2fgAs1iVZUu XaMA/55qcBhOuWNlhMY9oQEEnoshDYVsifSTuxSPiN87jLgJGeagMMIJblcWXI+TBRg7 PpYhj1ckaXUa9mXCJ6jxegKmCrPQ2OmwXCcHOixmxb17T8Ypk7NFbtiAhA3TYac8nx6t NiJyufTNLkClrg30Z8iyWmKA62DYvxKcAn8qQMxHP6Jh8JcwiI2eArQto5px5/6NKobB 6+Yb4mpZd/rnh2oyazllH+yOmZ6GqyEjSW3/IT5vWUaOSnX2LFoYM+7/rk8Ak1aWzZbe WCoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=di4x9TAxPTC63VUTw6cCZzEo+mtNXmMeptdsWxYJLB8=; b=D09sK/PvwtMQ0eI63wDcIIWryaRH7toss2xKlgefzXnHckfBVig8dJ3pCFVW0BG9kQ QzYENvvs34e0qpvPdMLkmoePfPNunOC0dnJ89dglLScpFpgilFObb/hdq2RqX6fL8MEo qAwjEPdRQ/DRAlB7SpKXVxVCNVtYlsT6Dv5DCdjTYXYB4chwEW4fHzlFqBVjEexag2Nv Mpb6GW48A1QO0sQi39HA155drfblslHa3W+OMXykUmV7sMdM2jDWmOiJb3F6uPL2/xOA kJGOkx93KaINbz+ez2iQw2E+mAvrorppdMD3nuxNvA9ub+lHWxaAeBRDNPwjTrefo2LP +N+A== X-Gm-Message-State: ACgBeo39clKkxVLQwEv8GeYrv0O1tIgVLSIxtI42lvPx0JVq2kRDdXjS a7Kd9OOn7FcN8064ss+yD0Y= X-Google-Smtp-Source: AA6agR64WSpjDVGBBm99fvmaS+23o2D3WuzEOTJyjJsEaephpsqj3dpS8oqdg0X/tYTtS6ORrxHD5Q== X-Received: by 2002:a17:907:d94:b0:73e:82a6:d284 with SMTP id go20-20020a1709070d9400b0073e82a6d284mr31246780ejc.392.1662361592442; Mon, 05 Sep 2022 00:06:32 -0700 (PDT) Received: from localhost.localdomain ([2a04:241e:502:a080:40ec:9f50:387:3cfb]) by smtp.gmail.com with ESMTPSA id n27-20020a056402515b00b0043cf2e0ce1csm5882775edd.48.2022.09.05.00.06.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Sep 2022 00:06:31 -0700 (PDT) From: Leonard Crestez To: David Ahern , Eric Dumazet , Dmitry Safonov <0x7f454c46@gmail.com> Cc: Francesco Ruggeri , Salam Noureddine , Philip Paeps , Shuah Khan , "David S. Miller" , Herbert Xu , Kuniyuki Iwashima , Hideaki YOSHIFUJI , Jakub Kicinski , Yuchung Cheng , Mat Martineau , Christoph Paasch , Ivan Delalande , Caowangbao , Priyaranjan Jha , netdev@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v8 11/26] tcp: authopt: Add support for signing skb-less replies Date: Mon, 5 Sep 2022 10:05:47 +0300 Message-Id: <6f0cd64a171de117ca98dbbd4f6bb56948196cb7.1662361354.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 1fa1b968c80c..9bc0f58a78cb 100644 --- a/include/net/tcp_authopt.h +++ b/include/net/tcp_authopt.h @@ -114,10 +114,17 @@ 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 bb74ab96b18f..0260173cd546 100644 --- a/net/ipv4/tcp_authopt.c +++ b/net/ipv4/tcp_authopt.c @@ -940,10 +940,72 @@ 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; @@ -1210,10 +1272,92 @@ int tcp_authopt_hash(char *hash_location, 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; +} + +/* * tcp_authopt_lookup_recv - lookup key for receive * * @sk: Receive socket * @skb: Packet, used to compare addr and iface * @net: Per-namespace information containing keys