From patchwork Mon Jan 24 12:12:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 536530 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 A3AB5C4332F for ; Mon, 24 Jan 2022 12:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242650AbiAXMO7 (ORCPT ); Mon, 24 Jan 2022 07:14:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239296AbiAXMOF (ORCPT ); Mon, 24 Jan 2022 07:14:05 -0500 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58338C061765; Mon, 24 Jan 2022 04:13:40 -0800 (PST) Received: by mail-ed1-x535.google.com with SMTP id p12so56231206edq.9; Mon, 24 Jan 2022 04:13:40 -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=U2mXf2WXVZ5apcoUUDJSkauSWrTBrA2j8Gq8gmjJmeg=; b=bWdNLPF4TA1eQYTMuRtBo+AEqLNxNqPbgt5q4jnHgoVoxhhpSVMolZ0RJhhmpewNe7 Xx2gcZirTm6TCdTCAdAV3gnRjTJXaLlumKiNhpbsOSVXgLC0kQy+rcK1ycwE5gflC1mF vvxYKLvBcSb/JfA7kr7/U7EYDadCfHQSbKmAyBwzWf5o7VL/d3feamS/sFR0wATZYNzF izxE+Pt8iCmgi+nfmY/DxgUl2649XZ+5qxbNbV7vwjeLMKuzn7dkh1ZIW/WD9gULw5Il C+4ZO0DzsCj2jBl92O4ohYgWYrKHEb0gpokI/VwfRRBmfApvvEVksTAziFylMN8q7BHn x1Ew== 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=U2mXf2WXVZ5apcoUUDJSkauSWrTBrA2j8Gq8gmjJmeg=; b=TCD9g6Ta1EBWpC3JzaFeGwzIoQi4pNgU+4RNTfFC80E8NDrvlyk+NDtBe4ZLzDWCOD MBGTzfdhPvThIjMgR9Ag8l1ugC1SuhJU3AlmDdFdgHTsDXPoamH9F7EL/f67PjUf/w9u WYPvuBLgdlS4duWPF8zYWOgOuXAwB4lCFsFoxMLAmDE9o4jhjhDEVRogUORDHBjqR//E mnt8gSQ1Q03ocCV5AXUfS5slwRlOiVsWvw6q4s+A846piLU7cBPvMoqRoKQNYyszqKMS 4zKjBY2LLTHuw4DrKzO7zjhAh4PN7m1sI++Kabqx2tFzo7YLMRwSXZUzGybQrWeQ+tA8 99+Q== X-Gm-Message-State: AOAM532hXhGvk9kUHd9Shv0MspzAp4kBJNUY1a3IouJ2G7L2ksdh/TyR v0XKxsLvb0HP38R0KpEM91U= X-Google-Smtp-Source: ABdhPJwgV8l2/TF4uh8xjJ5HtzISrof0XakjK9m8PdjcCeDt+bTUyyjV9QCxz9EyCdm4hvj+GbpSaw== X-Received: by 2002:a05:6402:42d3:: with SMTP id i19mr13603965edc.52.1643026418779; Mon, 24 Jan 2022 04:13:38 -0800 (PST) Received: from ponky.lan ([2a04:241e:502:a09c:a21f:7a9f:9158:4a40]) by smtp.gmail.com with ESMTPSA id b16sm4847517eja.211.2022.01.24.04.13.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 04:13:38 -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 v5 10/20] tcp: authopt: Add support for signing skb-less replies Date: Mon, 24 Jan 2022 14:12:56 +0200 Message-Id: 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 3c05b6c55191..7a2e15dd80ba 100644 --- a/net/ipv4/tcp_authopt.c +++ b/net/ipv4/tcp_authopt.c @@ -933,10 +933,72 @@ 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; @@ -1203,10 +1265,92 @@ 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