From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B2F0B606A31A for ; Mon, 26 Oct 2026 11:25:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=svndqFrt; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=jbMZ2+GO DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=6eCgEceiFsvuqOLL4DtIMBpdvoUh9ThW46mPVQRJDrA=; b=svndqFrtg8bD9U 4MafO8QBPVsga+WFBZqgR5MvP/d/DMgKYYpsmpjDANIFT86pqiFaQZ5AhYOWR+V/BQzEZ4bfIsZbv Lrvu4vibeMawKW4+ydL974CqCRkz2omYZCf2as8I5Eq66Ue8F/oKV0ux8y0c9SuQUWJqUE5E3s2u+ 2f/AQ8bPz/kG8cQLk6MxElVrsHpAzn6ItFShlZJY9mz6FSwVA5WoxRNfPw8dWqFQgiCEVxWO6k2rs UOVFqt5/CER94ZLcqYPUJ6xNZCAa7yElo9ap3fxay+eRhsk/XPleoW8+vLpJr7vm2CuWsbr1+EVIv ZoIPBS1mAmS00WCrW9OA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLIpl-00000002Mud-0OU1; Mon, 26 Oct 2026 11:25:45 +0000 Received: from mail-yx2-x07.google.com ([2607:f8b0:4864:41::7]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLIpi-00000002MuG-3Gmv for linux-nvme@lists.infradead.org; Mon, 26 Oct 2026 11:25:43 +0000 Received: by mail-yx2-x07.google.com with SMTP id 00721157ae682-8a72cead747so6821507b3.0 for ; Mon, 26 Oct 2026 04:25:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1793013941; x=1793618741; darn=lists.infradead.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=6eCgEceiFsvuqOLL4DtIMBpdvoUh9ThW46mPVQRJDrA=; b=jbMZ2+GOhwjzVAL054WTh41PevL+gJfu/yoIV/IJdT3dn6pfshP0jmwW9OOFqvDLgJ KzPW0FZavgHdSddub5Eiw5S/YlADcRjSpCVMtaFhVNAg8UsrLQkAGftdPmgbNvJBAogP SgfvTFKm9et5xiWqnDyDFE2DMO4L+gbYY/au9i6EZ2V36tJx/IiOvK77Rl53KewkIv4g 685qc+eFsKzx1B+YNy5+fWB/wDR7bsjfQO7wdTSh6VzjmgFQXplWGniJQnhbOSrotMpq t826PKzwdzTwb/B5fVMN7uUkHMeX+kdsC2QihorJe4RR1LhbqqTPviQog+idpSOnwUAu 1/gA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793013941; x=1793618741; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=6eCgEceiFsvuqOLL4DtIMBpdvoUh9ThW46mPVQRJDrA=; b=dd7atRZz518Oo52/AX7xFQuw0/eeFZOVmPZqd6KzifRTER+M1JqEbqSa8C31HbG/L/ HNLpIvj41okrgeShVfJxH7Z3rxUo04f4rhn9RbGBpZf2/JIZc5hN/M8Z00ZlgW9EvpBM X8ot2dBv2zffBddNI6sQCDu6E/WbIZxMtV11mov/cH1coiUTsDHdbG+7CWt7k/pdF62j gsfglRn2/+512QD7bDoGSQJkCuegoM50np/5amYM7ZDRAa5yhlnf4px5vUCK/kY5AIyK kKpf/Y0elrkqON6HjUX3RvLoIZFVr0bv62T7Os2tpdiJrIzGC1NO39Nyz2aB4LVDAOum yr/A== X-Forwarded-Encrypted: i=1; AKwUvBxbiSccsysxqh4H1z0mv3frPhL2LQ30rEAvnnNop7njdW55KC0DXonGAtgkzQowIJpcSTn1CmVYY+2/@lists.infradead.org X-Gm-Message-State: AFq9FYJpUciwjhi9+6CjeILWj3ipeyYx5YmyGhUDuguN/YIK+MulAHaP vCTNFFa+dEuJ3oHtxbrx/dqprnOE82+u6ot1T0LX3B+odUSLmHl9EwTy X-Gm-Gg: AYBFou2ipLo9Ay8CjIZBLb3gdBcR6UL2WScqsitbY6ydp7rMHQkE6ZTzCy6qTyZ6b9B cF8L2o7vSeOMWzJd/cyPDhncnodBL2LkkOzAFCti8uolEn/8s+QVL621IH1LfK6dTGo8ukw+3Dc PFPcDmSBnebO5zNwQFA5FVIfarNrzViQGg/BH0viqGjqi3GZXrQeMjLp4b8TeKBStzhlTGUoM+d 36yXJxL51iXMHezX2XcvDlbRY7iOCpOslgVPjiolyWCPF6bU13C0DWBO6T6oJ9rDxtdstq8dpXS grIPhTMVwpu9/wiXOfy9XwEAVDvp8pVEAdRrxA/m5yexU/W+in0r6cvK3R5NqUX+gzVVist9i+R ppWS2lxfJLjHd+pvonKKfMIFK03OxQsZm4St7R71KAgjRh34mhvnIVzZM0TNgR4ea+3voPv3vfY Nvf205O6eRB7L+d4RCHgXdSciLQ5zHkJccIf4IOICi2rKSreJYMw5o8uj4vmBxWj55o64HFvDYo lpvzVVjXb4u8GzAwixaz6kkbJQUlKlmX2q9Ryc87fpKoJKIweAPkS8rHcZCQbx5 X-Received: by 2002:a05:690c:2788:b0:8b0:eab2:f502 with SMTP id 00721157ae682-8b166c93421mr38305577b3.61.1793013941439; Mon, 26 Oct 2026 04:25:41 -0700 (PDT) Received: from [10.0.0.48] ([71.69.222.122]) by smtp.gmail.com with ESMTPSA id 00721157ae682-8b166c5d605sm29719597b3.5.2026.10.26.04.25.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 26 Oct 2026 04:25:41 -0700 (PDT) Message-ID: Date: Mon, 26 Oct 2026 07:25:39 -0400 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC net-next 1/5] tls: add HKDF-Expand-Label for the TLS 1.3 key schedule To: Hannes Reinecke , John Fastabend , Jakub Kicinski , Sabrina Dubroca , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Jonathan Corbet , Shuah Khan , Randy Dunlap , Shuah Khan Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Hannes Reinecke , Chuck Lever , kernel-tls-handshake@lists.linux.dev, linux-nvme@lists.infradead.org, Alistair Francis , Martin Belanger References: <20261025-keyupdate-rfc-v1-0-60b7756eccbd@gmail.com> <20261025-keyupdate-rfc-v1-1-60b7756eccbd@gmail.com> Content-Language: en-US From: Martin Belanger In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261026_042542_823929_F082AD0A X-CRM114-Status: GOOD ( 14.95 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" X-Spam-Status: No, score=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/26/26 03:27, Hannes Reinecke wrote: > On 10/26/26 1:36 AM, Martin Belanger via B4 Relay wrote: >> From: Martin Belanger >> >> A TLS 1.3 KeyUpdate derives the next traffic secret, key and IV with >> HKDF-Expand-Label (RFC 9846, section 7.2). Add the helper for the >> kernel to do this itself. >> >> Only the part of the key schedule after the handshake is needed. The >> input is a traffic secret, which is already a pseudorandom key, so >> HKDF-Extract is not needed. Each output is at most Hash.length bytes, >> so each derivation is a single HMAC with the library SHA-256 or SHA-384 >> functions. >> >> Assisted-by: LLM >> Signed-off-by: Martin Belanger >> --- >>   net/tls/Kconfig    |  2 ++ >>   net/tls/Makefile   |  2 +- >>   net/tls/tls.h      |  2 ++ >>   net/tls/tls_hkdf.c | 82 >> ++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>   4 files changed, 87 insertions(+), 1 deletion(-) >> > And another HKDF implementation. Maybe it's time to split if off (again). > But anyway. > Yes. crypto/hkdf.c went away again in 6d888db2cfd9 ("crypto: remove HKDF library"), when fscrypt and nvme-auth moved to the HMAC library. tls_hkdf.c follows that pattern. It needs only HKDF-Expand-Label, which is one HMAC here. If a shared helper is wanted again, I would do it in a separate series. Thanks for the review. Martin > Reviewed-by: Hannes Reinecke > > Cheers, > > Hannes