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(The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). -- The document date (August 11, 2020) is 1347 days in the past. Is this intentional? Checking references for intended status: Experimental ---------------------------------------------------------------------------- == Outdated reference: A later version (-34) exists of draft-ietf-quic-transport-29 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group N. Banks 3 Internet-Draft Microsoft Corporation 4 Intended status: Experimental August 11, 2020 5 Expires: February 12, 2021 7 QUIC Disable Encryption 8 draft-banks-quic-disable-encryption-00 10 Abstract 12 The disable_1rtt_encryption transport parameter can be used to 13 negotiate the disablement of encryption on 1-RTT packets, allowing 14 for reduced CPU load and improved performance. This extension is 15 only meant to be used in environments where both endpoints completely 16 trust the path between themselves; not, for instance, on the open 17 internet. 19 Status of This Memo 21 This Internet-Draft is submitted in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF). Note that other groups may also distribute 26 working documents as Internet-Drafts. The list of current Internet- 27 Drafts is at https://datatracker.ietf.org/drafts/current/. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 This Internet-Draft will expire on February 12, 2021. 36 Copyright Notice 38 Copyright (c) 2020 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents 43 (https://trustee.ietf.org/license-info) in effect on the date of 44 publication of this document. Please review these documents 45 carefully, as they describe your rights and restrictions with respect 46 to this document. Code Components extracted from this document must 47 include Simplified BSD License text as described in Section 4.e of 48 the Trust Legal Provisions and are provided without warranty as 49 described in the Simplified BSD License. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 54 1.1. Terms and Definitions . . . . . . . . . . . . . . . . . . 2 55 1.2. Applicable Scenarios for Use . . . . . . . . . . . . . . 2 56 2. Specification . . . . . . . . . . . . . . . . . . . . . . . . 3 57 2.1. Disable 1-RTT Encryption Transport Parameter . . . . . . 3 58 2.2. Negotiating the Extension . . . . . . . . . . . . . . . . 3 59 2.3. Disabling 1-RTT Encryption . . . . . . . . . . . . . . . 4 60 2.4. Interactions with Path Changes . . . . . . . . . . . . . 4 61 3. Security Considerations . . . . . . . . . . . . . . . . . . . 4 62 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 63 5. Normative References . . . . . . . . . . . . . . . . . . . . 5 64 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 66 1. Introduction 68 By default QUIC Transport Protocol [I-D.ietf-quic-transport] provides 69 secured (authenticated and encrypted) connections via a TLS 70 handshake. The handshake allows for the endpoints to be 71 authenticated by a certificate and then securely generates shared 72 secrets to encrypt the QUIC packet traffic. Post-handshake, this 73 packet encryption can occupy a considerable percentage of CPU usage, 74 depending on the scenario. Additionally, there are scenarios where 75 the protections given by this encryption are either unnecessary or 76 unwanted. For these scenarios, this document defines an extension to 77 the QUIC protocol to allow for mutually participating endpoints to 78 negotiate the disablement of encryption for the 1-RTT packets sent 79 after the handshake. 81 1.1. Terms and Definitions 83 The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 84 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 85 "OPTIONAL" in this document are to be interpreted as described in BCP 86 14 [RFC2119] [RFC8174] when, and only when, they appear in all 87 capitals, as shown here. 89 1.2. Applicable Scenarios for Use 91 QUIC connections are generally meant to always be encrypted, to 92 prevent unauthenticated middleboxes from reading or modifying the 93 QUIC packets. This is the desired behavior for most environments; 94 especially any that go over the open internet. There are two 95 possible scenarios where disabling packet encryption makes sense: 97 o Trusted Environment/Path - There are scenarios or environments 98 where there is no need for the additional security measures of 99 QUIC encryption; such as walled-gardens or tunneled connections. 100 These scenarios are either already trusted or secured by other 101 means. 103 o Performance Testing - When the actual contents of the QUIC packets 104 are unimportant and the goal is purely to measure the performance 105 characteristics of either the network, machine or QUIC 106 implementation without encryption. 108 2. Specification 110 The disable_1rtt_encryption transport parameter used for negotiating 111 the use of the extension is defined below. 113 2.1. Disable 1-RTT Encryption Transport Parameter 115 The disable_1rtt_encryption transport parameter can be sent by both a 116 client and server. The transport parameter is sent with an optional 117 variable-length value by the client and an empty value by the server; 118 a client that understands this transport parameter MUST treat the 119 receipt of a non-empty value as a connection error of type 120 TRANSPORT_PARAMETER_ERROR. 122 Advertising the disable_1rtt_encryption transport parameter indicates 123 that the endpoint wishes to disable encryption for 1-RTT packets. 124 Both sides must advertise support for the feature for it to be 125 considered successfully negotiated. 127 If successfully negotiated, all packets that would normally be 128 encrypted with the 1-RTT key are instead sent as cleartext; both 129 header and packet protections are disabled. 131 2.2. Negotiating the Extension 133 The payload sent in the transport parameter by the client, along with 134 any other information the server has about the client (such as IP 135 address) may be used to negotiate the extension on the server side. 136 The TP payload could be considered a key or identifier used by the 137 server to verify the client should be allowed to disable encryption. 138 These additional security measures are optional, but RECOMMENDED to 139 ensure encryption is not accidentally enabled when it should not be. 141 2.3. Disabling 1-RTT Encryption 143 When the extension is negotiated, all aspects of encryption on 1-RTT 144 packets are removed: 146 o Header protection 148 o Payload protection 150 o AEAD tag 152 This effectively gives the transport an additional 16 bytes per 153 packet to be used for payload, since it is no longer including an 154 AEAD tag. 156 Because the AEAD tag is removed along with the encryption, the UDP 157 checksum must be relied upon to determine any packet corruption. 159 2.4. Interactions with Path Changes 161 When making the trust determination about the path, each endpoints 162 must take into account possible path changes; NAT rebinding for 163 instance. An endpoint MUST NOT enable enable this extension if it is 164 possible for the path to change during the connection to some 165 untrusted state. 167 Additionally, a client MUST NOT try to migrate to any path that is 168 untrusted if this extension is negotiated. If a server receives a 169 packet for a connection with this extension negotiated on an 170 untrusted path, it MUST silently drop the packet. 172 3. Security Considerations 174 Disabling encryption for 1-RTT packets has some fairly obvious 175 security drawbacks: 177 o Packets can be read, modified and injected by any middleboxes 179 This extension is not meant to be used for any practical application 180 protocol on the open internet. Internet facing servers MUST NOT 181 enable this extension. Clients that do not trust their network and 182 path to the server MUST NOT enable this extension. 184 This extension does not modify the packet protections used during the 185 handshake, so the handshake can still be securely authenticated. 186 This prevents scenarios where one endpoint might trust (or think it 187 trusts) the path, but the other endpoint does not, and a man-in-the- 188 middle tries to force this extension to be used. 190 To prevent accidental use of the feature on production systems it is 191 RECOMMENDED for servers to have additional measures such as IP 192 filtering or a security key. 194 4. IANA Considerations 196 This document registers a new value in the QUIC Transport Parameter 197 Registry: 199 Value: TBD (using value 0xBAAD in early deployments) 201 Parameter Name: disable_1rtt_encryption 203 Specification: Indicates disabled 1-RTT encryption is being 204 negotiated 206 5. Normative References 208 [I-D.ietf-quic-transport] 209 Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed 210 and Secure Transport", draft-ietf-quic-transport-29 (work 211 in progress), June 2020. 213 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 214 Requirement Levels", BCP 14, RFC 2119, 215 DOI 10.17487/RFC2119, March 1997, 216 . 218 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 219 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 220 May 2017, . 222 Author's Address 224 Nick Banks 225 Microsoft Corporation 227 Email: nibanks@microsoft.com