Return-Path: X-Original-To: quic-issues@ietfa.amsl.com Delivered-To: quic-issues@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2D8BD12008A for ; Mon, 26 Aug 2019 15:37:40 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -8 X-Spam-Level: X-Spam-Status: No, score=-8 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=github.com Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fAWfmM7Rh6iS for ; Mon, 26 Aug 2019 15:37:38 -0700 (PDT) Received: from out-18.smtp.github.com (out-18.smtp.github.com [192.30.252.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 04F26120013 for ; Mon, 26 Aug 2019 15:37:37 -0700 (PDT) Date: Mon, 26 Aug 2019 15:37:37 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1566859057; bh=CJYA7HR+K4A1QWZJBAAaLzfY2ARNAk/PzaoOAebyKO0=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=CCFMRv6UgC1ylT8TgRpKVs2QMoLgPw/fJiHta218/M9/EZ8gplXPbnoY1iq95A26R vPBwIkkIRUsboORSIZzixbOm2fyrBe6fQJTITrJPOa+mLubMtZdvWTGo1dfbBGlxAw 80zN9IbB4hgJEmd5jASMj+J/6Hrnn7XWfCI5fWBw= From: Martin Thomson Reply-To: quicwg/base-drafts To: quicwg/base-drafts Cc: Subscribed Message-ID: In-Reply-To: References: Subject: Re: [quicwg/base-drafts] Receiver's behavior on key update (#2791) Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="--==_mimepart_5d645f312f139_342c3f8e272cd9644912a4"; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: list X-GitHub-Sender: martinthomson X-GitHub-Recipient: quic-issues X-GitHub-Reason: subscribed X-Auto-Response-Suppress: All X-GitHub-Recipient-Address: quic-issues@ietf.org Archived-At: X-BeenThere: quic-issues@ietf.org X-Mailman-Version: 2.1.29 List-Id: Notification list for GitHub issues related to the QUIC WG List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Aug 2019 22:37:40 -0000 ----==_mimepart_5d645f312f139_342c3f8e272cd9644912a4 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit martinthomson commented on this pull request. > -what it is expecting. It creates a new secret (see Section 7.2 of {{!TLS13}}) -and the corresponding read key and IV using the KDF function provided by TLS. -The header protection key is not updated. - -If the packet can be decrypted and authenticated using the updated key and IV, -then the keys the endpoint uses for packet protection are also updated. The -next packet sent by the endpoint MUST then use the new keys. Once an endpoint -has sent a packet encrypted with a given key phase, it MUST NOT send a packet -encrypted with an older key phase. +While only one send key is used at a time, an endpoint MUST retain at least two +receive keys. + +Packets received with the current key phase are unprotected using the +corresponding receive key. When a packet arrives with the opposite key phase, +an endpoint determines which receive key to use by tracking the lowest packet +number among the packets received with the currently key phase. If a packet is ```suggestion number among the packets received with the current key phase. If a packet is ``` > + +Packets received with the current key phase are unprotected using the +corresponding receive key. When a packet arrives with the opposite key phase, +an endpoint determines which receive key to use by tracking the lowest packet +number among the packets received with the currently key phase. If a packet is +received that has a different KEY_PHASE bit and a lower packet number than this +value, the endpoint uses the receive key of the previous key phase for +unprotecting the packet, if that key is available. If the packet has a higher +packet number, the endpoint derives the receive key of the next key phase by +calculating the next secret (see Section 7.2 of {{!TLS13}}), the corresponding +read key and IV using the KDF function provided by TLS, unless the next receive +key has already been derived. The header protection key is not updated. + +Once derived, an endpoint retains the receive key of the next key phase, to +prevent attackers from targeting the calculation process of the next receive key +as an attack vector. An endpoint that retains only two receive keys drops the An attack on what? > +corresponding receive key. When a packet arrives with the opposite key phase, +an endpoint determines which receive key to use by tracking the lowest packet +number among the packets received with the currently key phase. If a packet is +received that has a different KEY_PHASE bit and a lower packet number than this +value, the endpoint uses the receive key of the previous key phase for +unprotecting the packet, if that key is available. If the packet has a higher +packet number, the endpoint derives the receive key of the next key phase by +calculating the next secret (see Section 7.2 of {{!TLS13}}), the corresponding +read key and IV using the KDF function provided by TLS, unless the next receive +key has already been derived. The header protection key is not updated. + +Once derived, an endpoint retains the receive key of the next key phase, to +prevent attackers from targeting the calculation process of the next receive key +as an attack vector. An endpoint that retains only two receive keys drops the +receive key of the previous key phase in favor of retaining the next receive +key. This has to happen *after* you successfully use the new key. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/quicwg/base-drafts/pull/2791#pullrequestreview-279593687 ----==_mimepart_5d645f312f139_342c3f8e272cd9644912a4 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

@martinthomson commented on this pull request.

=0D =0D
=0D =0D

In draft-ietf-quic-tls.md:

=0D 
> -what it is expecting.  It creates a new s=
ecret (see Section 7.2 of {{!TLS13}})=0D
-and the corresponding read key and IV using the KDF function provided by=
 TLS.=0D
-The header protection key is not updated.=0D
-=0D
-If the packet can be decrypted and authenticated using the updated key a=
nd IV,=0D
-then the keys the endpoint uses for packet protection are also updated. =
 The=0D
-next packet sent by the endpoint MUST then use the new keys.  Once an en=
dpoint=0D
-has sent a packet encrypted with a given key phase, it MUST NOT send a p=
acket=0D
-encrypted with an older key phase.=0D
+While only one send key is used at a time, an endpoint MUST retain at le=
ast two=0D
+receive keys.=0D
+=0D
+Packets received with the current key phase are unprotected using the=0D=

+corresponding receive key.  When a packet arrives with the opposite key =
phase,=0D
+an endpoint determines which receive key to use by tracking the lowest p=
acket=0D
+number among the packets received with the currently key phase.  If a pa=
cket is=0D
=0D =E2=AC=87=EF=B8=8F Suggested change=0D 
-number among the packets received with the cu=
rrently key phase.  If a packet is=0D
+number among the packets received with the current key phase.  If a pack=
et is=0D
=0D =0D =0D
=0D =0D

In draft-ietf-quic-tls.md:

=0D 
> +=0D
+Packets received with the current key phase are unprotected using the=0D=

+corresponding receive key.  When a packet arrives with the opposite key =
phase,=0D
+an endpoint determines which receive key to use by tracking the lowest p=
acket=0D
+number among the packets received with the currently key phase.  If a pa=
cket is=0D
+received that has a different KEY_PHASE bit and a lower packet number th=
an this=0D
+value, the endpoint uses the receive key of the previous key phase for=0D=

+unprotecting the packet, if that key is available.  If the packet has a =
higher=0D
+packet number, the endpoint derives the receive key of the next key phas=
e by=0D
+calculating the next secret (see Section 7.2 of {{!TLS13}}), the corresp=
onding=0D
+read key and IV using the KDF function provided by TLS, unless the next =
receive=0D
+key has already been derived.  The header protection key is not updated.=
=0D
+=0D
+Once derived, an endpoint retains the receive key of the next key phase,=
 to=0D
+prevent attackers from targeting the calculation process of the next rec=
eive key=0D
+as an attack vector.  An endpoint that retains only two receive keys dro=
ps the=0D
=0D

An attack on what?

=0D =0D
=0D =0D

In draft-ietf-quic-tls.md:

=0D 
> +corresponding receive key.  When a packet=
 arrives with the opposite key phase,=0D
+an endpoint determines which receive key to use by tracking the lowest p=
acket=0D
+number among the packets received with the currently key phase.  If a pa=
cket is=0D
+received that has a different KEY_PHASE bit and a lower packet number th=
an this=0D
+value, the endpoint uses the receive key of the previous key phase for=0D=

+unprotecting the packet, if that key is available.  If the packet has a =
higher=0D
+packet number, the endpoint derives the receive key of the next key phas=
e by=0D
+calculating the next secret (see Section 7.2 of {{!TLS13}}), the corresp=
onding=0D
+read key and IV using the KDF function provided by TLS, unless the next =
receive=0D
+key has already been derived.  The header protection key is not updated.=
=0D
+=0D
+Once derived, an endpoint retains the receive key of the next key phase,=
 to=0D
+prevent attackers from targeting the calculation process of the next rec=
eive key=0D
+as an attack vector.  An endpoint that retains only two receive keys dro=
ps the=0D
+receive key of the previous key phase in favor of retaining the next rec=
eive=0D
+key.=0D
=0D

This has to happen after you successfully use the new key.=0D =0D

&m= dash;
You are receiving this because you are subscribed to this thre= ad.
Reply to this email directly, view it on GitHub, or mute the th= read.3D""=

=0D = ----==_mimepart_5d645f312f139_342c3f8e272cd9644912a4--