draft-ietf-quic-tls-02.txt   draft-ietf-quic-tls-03.txt 
QUIC M. Thomson, Ed. QUIC M. Thomson, Ed.
Internet-Draft Mozilla Internet-Draft Mozilla
Intended status: Standards Track S. Turner, Ed. Intended status: Standards Track S. Turner, Ed.
Expires: September 14, 2017 sn3rd Expires: November 22, 2017 sn3rd
March 13, 2017 May 21, 2017
Using Transport Layer Security (TLS) to Secure QUIC Using Transport Layer Security (TLS) to Secure QUIC
draft-ietf-quic-tls-02 draft-ietf-quic-tls-03
Abstract Abstract
This document describes how Transport Layer Security (TLS) can be This document describes how Transport Layer Security (TLS) is used to
used to secure QUIC. secure QUIC.
Note to Readers Note to Readers
Discussion of this draft takes place on the QUIC working group Discussion of this draft takes place on the QUIC working group
mailing list (quic@ietf.org), which is archived at mailing list (quic@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/search/?email_list=quic . https://mailarchive.ietf.org/arch/search/?email_list=quic .
Working Group information can be found at https://github.com/quicwg ; Working Group information can be found at https://github.com/quicwg ;
source code and issues list for this draft can be found at source code and issues list for this draft can be found at
https://github.com/quicwg/base-drafts/labels/tls . https://github.com/quicwg/base-drafts/labels/tls .
skipping to change at page 1, line 42 skipping to change at page 1, line 42
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 14, 2017. This Internet-Draft will expire on November 22, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 23 skipping to change at page 2, line 23
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4
3. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 4 3. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 4
3.1. TLS Overview . . . . . . . . . . . . . . . . . . . . . . 5 3.1. TLS Overview . . . . . . . . . . . . . . . . . . . . . . 5
3.2. TLS Handshake . . . . . . . . . . . . . . . . . . . . . . 6 3.2. TLS Handshake . . . . . . . . . . . . . . . . . . . . . . 6
4. TLS Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. TLS Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Handshake and Setup Sequence . . . . . . . . . . . . . . 8 4.1. Handshake and Setup Sequence . . . . . . . . . . . . . . 7
4.2. Interface to TLS . . . . . . . . . . . . . . . . . . . . 9 4.2. Interface to TLS . . . . . . . . . . . . . . . . . . . . 9
4.2.1. Handshake Interface . . . . . . . . . . . . . . . . . 9 4.2.1. Handshake Interface . . . . . . . . . . . . . . . . . 9
4.2.2. Source Address Validation . . . . . . . . . . . . . . 11 4.2.2. Source Address Validation . . . . . . . . . . . . . . 10
4.2.3. Key Ready Events . . . . . . . . . . . . . . . . . . 11 4.2.3. Key Ready Events . . . . . . . . . . . . . . . . . . 11
4.2.4. Secret Export . . . . . . . . . . . . . . . . . . . . 12 4.2.4. Secret Export . . . . . . . . . . . . . . . . . . . . 12
4.2.5. TLS Interface Summary . . . . . . . . . . . . . . . . 12 4.2.5. TLS Interface Summary . . . . . . . . . . . . . . . . 12
4.3. TLS Version . . . . . . . . . . . . . . . . . . . . . . . 13 4.3. TLS Version . . . . . . . . . . . . . . . . . . . . . . . 13
4.4. ClientHello Size . . . . . . . . . . . . . . . . . . . . 13 4.4. ClientHello Size . . . . . . . . . . . . . . . . . . . . 13
4.5. Peer Authentication . . . . . . . . . . . . . . . . . . . 14 4.5. Peer Authentication . . . . . . . . . . . . . . . . . . . 13
4.6. TLS Errors . . . . . . . . . . . . . . . . . . . . . . . 14 4.6. TLS Errors . . . . . . . . . . . . . . . . . . . . . . . 14
5. QUIC Packet Protection . . . . . . . . . . . . . . . . . . . 14 5. QUIC Packet Protection . . . . . . . . . . . . . . . . . . . 14
5.1. Installing New Keys . . . . . . . . . . . . . . . . . . . 15 5.1. Installing New Keys . . . . . . . . . . . . . . . . . . . 14
5.2. QUIC Key Expansion . . . . . . . . . . . . . . . . . . . 15 5.2. QUIC Key Expansion . . . . . . . . . . . . . . . . . . . 15
5.2.1. 0-RTT Secret . . . . . . . . . . . . . . . . . . . . 15 5.2.1. 0-RTT Secret . . . . . . . . . . . . . . . . . . . . 15
5.2.2. 1-RTT Secrets . . . . . . . . . . . . . . . . . . . . 16 5.2.2. 1-RTT Secrets . . . . . . . . . . . . . . . . . . . . 15
5.2.3. Packet Protection Key and IV . . . . . . . . . . . . 17 5.2.3. Packet Protection Key and IV . . . . . . . . . . . . 17
5.3. QUIC AEAD Usage . . . . . . . . . . . . . . . . . . . . . 18 5.3. QUIC AEAD Usage . . . . . . . . . . . . . . . . . . . . . 17
5.4. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 19 5.4. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 18
5.5. Receiving Protected Packets . . . . . . . . . . . . . . . 19 5.5. Receiving Protected Packets . . . . . . . . . . . . . . . 19
6. Key Phases . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.6. Packet Number Gaps . . . . . . . . . . . . . . . . . . . 19
6.1. Packet Protection for the TLS Handshake . . . . . . . . . 20 6. Unprotected Packets . . . . . . . . . . . . . . . . . . . . . 19
6.1.1. Initial Key Transitions . . . . . . . . . . . . . . . 21 6.1. Integrity Check Processing . . . . . . . . . . . . . . . 19
6.1.2. Retransmission and Acknowledgment of Unprotected 6.2. The 64-bit FNV-1a Algorithm . . . . . . . . . . . . . . . 20
7. Key Phases . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.1. Packet Protection for the TLS Handshake . . . . . . . . . 21
7.1.1. Initial Key Transitions . . . . . . . . . . . . . . . 21
7.1.2. Retransmission and Acknowledgment of Unprotected
Packets . . . . . . . . . . . . . . . . . . . . . . . 22 Packets . . . . . . . . . . . . . . . . . . . . . . . 22
6.2. Key Update . . . . . . . . . . . . . . . . . . . . . . . 22 7.2. Key Update . . . . . . . . . . . . . . . . . . . . . . . 23
7. Client Address Validation . . . . . . . . . . . . . . . . . . 24
7.1. HelloRetryRequest Address Validation . . . . . . . . . . 24
7.2. NewSessionTicket Address Validation . . . . . . . . . . . 25
7.3. Address Validation Token Integrity . . . . . . . . . . . 26
8. Pre-handshake QUIC Messages . . . . . . . . . . . . . . . . . 26 8. Client Address Validation . . . . . . . . . . . . . . . . . . 24
8.1. Unprotected Packets Prior to Handshake Completion . . . . 27 8.1. HelloRetryRequest Address Validation . . . . . . . . . . 24
8.1.1. STREAM Frames . . . . . . . . . . . . . . . . . . . . 27 8.1.1. Stateless Address Validation . . . . . . . . . . . . 25
8.1.2. ACK Frames . . . . . . . . . . . . . . . . . . . . . 27 8.1.2. Sending HelloRetryRequest . . . . . . . . . . . . . . 26
8.1.3. WINDOW_UPDATE Frames . . . . . . . . . . . . . . . . 28 8.2. NewSessionTicket Address Validation . . . . . . . . . . . 26
8.1.4. Denial of Service with Unprotected Packets . . . . . 28 8.3. Address Validation Token Integrity . . . . . . . . . . . 27
8.2. Use of 0-RTT Keys . . . . . . . . . . . . . . . . . . . . 29 9. Pre-handshake QUIC Messages . . . . . . . . . . . . . . . . . 27
8.3. Receiving Out-of-Order Protected Frames . . . . . . . . . 29 9.1. Unprotected Packets Prior to Handshake Completion . . . . 28
9. QUIC-Specific Additions to the TLS Handshake . . . . . . . . 30 9.1.1. STREAM Frames . . . . . . . . . . . . . . . . . . . . 28
9.1. Protocol and Version Negotiation . . . . . . . . . . . . 30 9.1.2. ACK Frames . . . . . . . . . . . . . . . . . . . . . 28
9.2. QUIC Transport Parameters Extension . . . . . . . . . . . 31 9.1.3. Updates to Data and Stream Limits . . . . . . . . . . 29
9.3. Priming 0-RTT . . . . . . . . . . . . . . . . . . . . . . 31 9.1.4. Denial of Service with Unprotected Packets . . . . . 29
10. Security Considerations . . . . . . . . . . . . . . . . . . . 32 9.2. Use of 0-RTT Keys . . . . . . . . . . . . . . . . . . . . 30
10.1. Packet Reflection Attack Mitigation . . . . . . . . . . 32 9.3. Receiving Out-of-Order Protected Frames . . . . . . . . . 30
10.2. Peer Denial of Service . . . . . . . . . . . . . . . . . 32 10. QUIC-Specific Additions to the TLS Handshake . . . . . . . . 31
11. Error codes . . . . . . . . . . . . . . . . . . . . . . . . . 33 10.1. Protocol and Version Negotiation . . . . . . . . . . . . 31
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 33 10.2. QUIC Transport Parameters Extension . . . . . . . . . . 31
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 33 10.3. Priming 0-RTT . . . . . . . . . . . . . . . . . . . . . 32
13.1. Normative References . . . . . . . . . . . . . . . . . . 33 11. Security Considerations . . . . . . . . . . . . . . . . . . . 32
13.2. Informative References . . . . . . . . . . . . . . . . . 34 11.1. Packet Reflection Attack Mitigation . . . . . . . . . . 33
Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 35 11.2. Peer Denial of Service . . . . . . . . . . . . . . . . . 33
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 35 12. Error codes . . . . . . . . . . . . . . . . . . . . . . . . . 33
Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 35 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 34
C.1. Since draft-ietf-quic-tls-01: . . . . . . . . . . . . . . 35 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
C.2. Since draft-ietf-quic-tls-00: . . . . . . . . . . . . . . 35 14.1. Normative References . . . . . . . . . . . . . . . . . . 34
C.3. Since draft-thomson-quic-tls-01: . . . . . . . . . . . . 36 14.2. Informative References . . . . . . . . . . . . . . . . . 35
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 36 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 36
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 36
Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 36
C.1. Since draft-ietf-quic-tls-02 . . . . . . . . . . . . . . 36
C.2. Since draft-ietf-quic-tls-01 . . . . . . . . . . . . . . 36
C.3. Since draft-ietf-quic-tls-00 . . . . . . . . . . . . . . 37
C.4. Since draft-thomson-quic-tls-01 . . . . . . . . . . . . . 37
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37
1. Introduction 1. Introduction
QUIC [QUIC-TRANSPORT] provides a multiplexed transport. When used This document describes how QUIC [QUIC-TRANSPORT] is secured using
for HTTP [RFC7230] semantics [QUIC-HTTP] it provides several key Transport Layer Security (TLS) version 1.3 [I-D.ietf-tls-tls13]. TLS
advantages over HTTP/1.1 [RFC7230] or HTTP/2 [RFC7540] over TCP 1.3 provides critical latency improvements for connection
[RFC0793]. establishment over previous versions. Absent packet loss, most new
connections can be established and secured within a single round
This document describes how QUIC can be secured using Transport Layer trip; on subsequent connections between the same client and server,
Security (TLS) version 1.3 [I-D.ietf-tls-tls13]. TLS 1.3 provides the client can often send application data immediately, that is,
critical latency improvements for connection establishment over using a zero round trip setup.
previous versions. Absent packet loss, most new connections can be
established and secured within a single round trip; on subsequent
connections between the same client and server, the client can often
send application data immediately, that is, using a zero round trip
setup.
This document describes how the standardized TLS 1.3 can act a This document describes how the standardized TLS 1.3 acts a security
security component of QUIC. The same design could work for TLS 1.2, component of QUIC. The same design could work for TLS 1.2, though
though few of the benefits QUIC provides would be realized due to the few of the benefits QUIC provides would be realized due to the
handshake latency in versions of TLS prior to 1.3. handshake latency in versions of TLS prior to 1.3.
2. Notational Conventions 2. Notational Conventions
The words "MUST", "MUST NOT", "SHOULD", and "MAY" are used in this The words "MUST", "MUST NOT", "SHOULD", and "MAY" are used in this
document. It's not shouting; when they are capitalized, they have document. It's not shouting; when they are capitalized, they have
the special meaning defined in [RFC2119]. the special meaning defined in [RFC2119].
This document uses the terminology established in [QUIC-TRANSPORT]. This document uses the terminology established in [QUIC-TRANSPORT].
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+------------+ / / +------------+ / /
| QUIC | / / | QUIC | / /
| Packet |-------- Get Secret -------' / | Packet |-------- Get Secret -------' /
| Protection |<-------- Secret -----------' | Protection |<-------- Secret -----------'
+------------+ +------------+
Figure 1: QUIC and TLS Interactions Figure 1: QUIC and TLS Interactions
The initial state of a QUIC connection has packets exchanged without The initial state of a QUIC connection has packets exchanged without
any form of protection. In this state, QUIC is limited to using any form of protection. In this state, QUIC is limited to using
stream 1 and associated packets. Stream 1 is reserved for a TLS stream 0 and associated packets. Stream 0 is reserved for a TLS
connection. This is a complete TLS connection as it would appear connection. This is a complete TLS connection as it would appear
when layered over TCP; the only difference is that QUIC provides the when layered over TCP; the only difference is that QUIC provides the
reliability and ordering that would otherwise be provided by TCP. reliability and ordering that would otherwise be provided by TCP.
At certain points during the TLS handshake, keying material is At certain points during the TLS handshake, keying material is
exported from the TLS connection for use by QUIC. This keying exported from the TLS connection for use by QUIC. This keying
material is used to derive packet protection keys. Details on how material is used to derive packet protection keys. Details on how
and when keys are derived and used are included in Section 5. and when keys are derived and used are included in Section 5.
This arrangement means that some TLS messages receive redundant
protection from both the QUIC packet protection and the TLS record
protection. These messages are limited in number; the TLS connection
is rarely needed once the handshake completes.
3.1. TLS Overview 3.1. TLS Overview
TLS provides two endpoints a way to establish a means of TLS provides two endpoints with a way to establish a means of
communication over an untrusted medium (that is, the Internet) that communication over an untrusted medium (that is, the Internet) that
ensures that messages they exchange cannot be observed, modified, or ensures that messages they exchange cannot be observed, modified, or
forged. forged.
TLS features can be separated into two basic functions: an TLS features can be separated into two basic functions: an
authenticated key exchange and record protection. QUIC primarily authenticated key exchange and record protection. QUIC primarily
uses the authenticated key exchange provided by TLS but provides its uses the authenticated key exchange provided by TLS but provides its
own packet protection. own packet protection.
The TLS authenticated key exchange occurs between two entities: The TLS authenticated key exchange occurs between two entities:
client and server. The client initiates the exchange and the server client and server. The client initiates the exchange and the server
responds. If the key exchange completes successfully, both client responds. If the key exchange completes successfully, both client
and server will agree on a secret. TLS supports both pre-shared key and server will agree on a secret. TLS supports both pre-shared key
(PSK) and Diffie-Hellman (DH) key exchanges. PSK is the basis for (PSK) and Diffie-Hellman (DH) key exchanges. PSK is the basis for
0-RTT; the latter provides perfect forward secrecy (PFS) when the DH 0-RTT; the latter provides perfect forward secrecy (PFS) when the DH
keys are destroyed. keys are destroyed.
After completing the TLS handshake, the client will have learned and After completing the TLS handshake, the client will have learned and
authenticated an identity for the server and the server is optionally authenticated an identity for the server and the server is optionally
able to learn and authenticate an identity for the client. TLS able to learn and authenticate an identity for the client. TLS
supports X.509 certificate-based authentication [RFC5280] for both supports X.509 [RFC5280] certificate-based authentication for both
server and client. server and client.
The TLS key exchange is resistent to tampering by attackers and it The TLS key exchange is resistent to tampering by attackers and it
produces shared secrets that cannot be controlled by either produces shared secrets that cannot be controlled by either
participating peer. participating peer.
3.2. TLS Handshake 3.2. TLS Handshake
TLS 1.3 provides two basic handshake modes of interest to QUIC: TLS 1.3 provides two basic handshake modes of interest to QUIC:
o A full, 1-RTT handshake in which the client is able to send o A full 1-RTT handshake in which the client is able to send
application data after one round trip and the server immediately application data after one round trip and the server immediately
after receiving the first handshake message from the client. after receiving the first handshake message from the client.
o A 0-RTT handshake in which the client uses information it has o A 0-RTT handshake in which the client uses information it has
previously learned about the server to send immediately. This previously learned about the server to send application data
data can be replayed by an attacker so it MUST NOT carry a self- immediately. This application data can be replayed by an attacker
contained trigger for any non-idempotent action. so it MUST NOT carry a self-contained trigger for any non-
idempotent action.
A simplified TLS 1.3 handshake with 0-RTT application data is shown A simplified TLS 1.3 handshake with 0-RTT application data is shown
in Figure 2, see [I-D.ietf-tls-tls13] for more options and details. in Figure 2, see [I-D.ietf-tls-tls13] for more options and details.
Client Server Client Server
ClientHello ClientHello
(0-RTT Application Data) --------> (0-RTT Application Data) -------->
ServerHello ServerHello
{EncryptedExtensions} {EncryptedExtensions}
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relevant to this document: relevant to this document:
o The server can respond to a ClientHello with a HelloRetryRequest, o The server can respond to a ClientHello with a HelloRetryRequest,
which adds an additional round trip prior to the basic exchange. which adds an additional round trip prior to the basic exchange.
This is needed if the server wishes to request a different key This is needed if the server wishes to request a different key
exchange key from the client. HelloRetryRequest is also used to exchange key from the client. HelloRetryRequest is also used to
verify that the client is correctly able to receive packets on the verify that the client is correctly able to receive packets on the
address it claims to have (see [QUIC-TRANSPORT]). address it claims to have (see [QUIC-TRANSPORT]).
o A pre-shared key mode can be used for subsequent handshakes to o A pre-shared key mode can be used for subsequent handshakes to
avoid public key operations. This is the basis for 0-RTT data, reduce the number of public key operations. This is the basis for
even if the remainder of the connection is protected by a new 0-RTT data, even if the remainder of the connection is protected
Diffie-Hellman exchange. by a new Diffie-Hellman exchange.
4. TLS Usage 4. TLS Usage
QUIC reserves stream 1 for a TLS connection. Stream 1 contains a QUIC reserves stream 0 for a TLS connection. Stream 0 contains a
complete TLS connection, which includes the TLS record layer. Other complete TLS connection, which includes the TLS record layer. Other
than the definition of a QUIC-specific extension (see Section-TBD), than the definition of a QUIC-specific extension (see Section 10.2),
TLS is unmodified for this use. This means that TLS will apply TLS is unmodified for this use. This means that TLS will apply
confidentiality and integrity protection to its records. In confidentiality and integrity protection to its records. In
particular, TLS record protection is what provides confidentiality particular, TLS record protection is what provides confidentiality
protection for the TLS handshake messages sent by the server. protection for the TLS handshake messages sent by the server.
QUIC permits a client to send frames on streams starting from the QUIC permits a client to send frames on streams starting from the
first packet. The initial packet from a client contains a stream first packet. The initial packet from a client contains a stream
frame for stream 1 that contains the first TLS handshake messages frame for stream 0 that contains the first TLS handshake messages
from the client. This allows the TLS handshake to start with the from the client. This allows the TLS handshake to start with the
first packet that a client sends. first packet that a client sends.
QUIC packets are protected using a scheme that is specific to QUIC, QUIC packets are protected using a scheme that is specific to QUIC,
see Section 5. Keys are exported from the TLS connection when they see Section 5. Keys are exported from the TLS connection when they
become available using a TLS exporter (see Section 7.3.3 of become available using a TLS exporter (see Section 7.5 of
[I-D.ietf-tls-tls13] and Section 5.2). After keys are exported from [I-D.ietf-tls-tls13] and Section 5.2). After keys are exported from
TLS, QUIC manages its own key schedule. TLS, QUIC manages its own key schedule.
4.1. Handshake and Setup Sequence 4.1. Handshake and Setup Sequence
The integration of QUIC with a TLS handshake is shown in more detail The integration of QUIC with a TLS handshake is shown in more detail
in Figure 3. QUIC "STREAM" frames on stream 1 carry the TLS in Figure 3. QUIC "STREAM" frames on stream 0 carry the TLS
handshake. QUIC performs loss recovery [QUIC-RECOVERY] for this handshake. QUIC performs loss recovery [QUIC-RECOVERY] for this
stream and ensures that TLS handshake messages are delivered in the stream and ensures that TLS handshake messages are delivered in the
correct order. correct order.
Client Server Client Server
@C QUIC STREAM Frame(s) <1>: @C QUIC STREAM Frame(s) <0>:
ClientHello ClientHello
+ QUIC Extension + QUIC Extension
--------> -------->
0-RTT Key => @0 0-RTT Key => @0
@0 QUIC STREAM Frame(s) <any stream>: @0 QUIC STREAM Frame(s) <any stream>:
Replayable QUIC Frames Replayable QUIC Frames
--------> -------->
QUIC STREAM Frame <1>: @C QUIC STREAM Frame <0>: @C
ServerHello ServerHello
{TLS Handshake Messages} {TLS Handshake Messages}
<-------- <--------
1-RTT Key => @1 1-RTT Key => @1
QUIC Frames <any> @1 QUIC Frames <any> @1
<-------- <--------
@C QUIC STREAM Frame(s) <1>: @C QUIC STREAM Frame(s) <0>:
(EndOfEarlyData) (EndOfEarlyData)
{Finished} {Finished}
--------> -------->
@1 QUIC Frames <any> <-------> QUIC Frames <any> @1 @1 QUIC Frames <any> <-------> QUIC Frames <any> @1
Figure 3: QUIC over TLS Handshake Figure 3: QUIC over TLS Handshake
In Figure 3, symbols mean: In Figure 3, symbols mean:
o "<" and ">" enclose stream numbers. o "<" and ">" enclose stream numbers.
o "@" indicates the key phase that is currently used for protecting o "@" indicates the keys that are used for protecting the QUIC
QUIC packets. packet (C = cleartext, with integrity only; 0 = 0-RTT keys; 1 =
1-RTT keys).
o "(" and ")" enclose messages that are protected with TLS 0-RTT o "(" and ")" enclose messages that are protected with TLS 0-RTT
handshake or application keys. handshake or application keys.
o "{" and "}" enclose messages that are protected by the TLS o "{" and "}" enclose messages that are protected by the TLS
Handshake keys. Handshake keys.
If 0-RTT is not attempted, then the client does not send packets If 0-RTT is not attempted, then the client does not send packets
protected by the 0-RTT key (@0). In that case, the only key protected by the 0-RTT key (@0). In that case, the only key
transition on the client is from unprotected packets (@C) to 1-RTT transition on the client is from cleartext packets (@C) to 1-RTT
protection (@1), which happens after it sends its final set of TLS protection (@1), which happens after it sends its final set of TLS
handshake messages. handshake messages.
Note: the client uses two different types of cleartext packet during
the handshake. The Client Initial packet carries a TLS ClientHello
message; the remainder of the TLS handshake is carried in Client
Cleartext packets.
The server sends TLS handshake messages without protection (@C). The The server sends TLS handshake messages without protection (@C). The
server transitions from no protection (@C) to full 1-RTT protection server transitions from no protection (@C) to full 1-RTT protection
(@1) after it sends the last of its handshake messages. (@1) after it sends the last of its handshake messages.
Some TLS handshake messages are protected by the TLS handshake record Some TLS handshake messages are protected by the TLS handshake record
protection. These keys are not exported from the TLS connection for protection. These keys are not exported from the TLS connection for
use in QUIC. QUIC packets from the server are sent in the clear use in QUIC. QUIC packets from the server are sent in the clear
until the final transition to 1-RTT keys. until the final transition to 1-RTT keys.
The client transitions from cleartext (@C) to 0-RTT keys (@0) when The client transitions from cleartext (@C) to 0-RTT keys (@0) when
sending 0-RTT data, and subsequently to to 1-RTT keys (@1) after its sending 0-RTT data, and subsequently to to 1-RTT keys (@1) after its
second flight of TLS handshake messages. This creates the potential second flight of TLS handshake messages. This creates the potential
for unprotected packets to be received by a server in close proximity for unprotected packets to be received by a server in close proximity
to packets that are protected with 1-RTT keys. to packets that are protected with 1-RTT keys.
More information on key transitions is included in Section 6.1. More information on key transitions is included in Section 7.1.
4.2. Interface to TLS 4.2. Interface to TLS
As shown in Figure 1, the interface from QUIC to TLS consists of four As shown in Figure 1, the interface from QUIC to TLS consists of four
primary functions: Handshake, Source Address Validation, Key Ready primary functions: Handshake, Source Address Validation, Key Ready
Events, and Secret Export. Events, and Secret Export.
Additional functions might be needed to configure TLS. Additional functions might be needed to configure TLS.
4.2.1. Handshake Interface 4.2.1. Handshake Interface
In order to drive the handshake, TLS depends on being able to send In order to drive the handshake, TLS depends on being able to send
and receive handshake messages on stream 1. There are two basic and receive handshake messages on stream 0. There are two basic
functions on this interface: one where QUIC requests handshake functions on this interface: one where QUIC requests handshake
messages and one where QUIC provides handshake packets. messages and one where QUIC provides handshake packets.
Before starting the handshake QUIC provides TLS with the transport Before starting the handshake QUIC provides TLS with the transport
parameters (see Section 9.2) that it wishes to carry. parameters (see Section 10.2) that it wishes to carry.
A QUIC client starts TLS by requesting TLS handshake octets from TLS. A QUIC client starts TLS by requesting TLS handshake octets from TLS.
The client acquires handshake octets before sending its first packet. The client acquires handshake octets before sending its first packet.
A QUIC server starts the process by providing TLS with stream 1 A QUIC server starts the process by providing TLS with stream 0
octets. octets.
Each time that an endpoint receives data on stream 1, it delivers the Each time that an endpoint receives data on stream 0, it delivers the
octets to TLS if it is able. Each time that TLS is provided with new octets to TLS if it is able. Each time that TLS is provided with new
data, new handshake octets are requested from TLS. TLS might not data, new handshake octets are requested from TLS. TLS might not
provide any octets if the handshake messages it has received are provide any octets if the handshake messages it has received are
incomplete or it has no data to send. incomplete or it has no data to send.
Once the TLS handshake is complete, this is indicated to QUIC along Once the TLS handshake is complete, this is indicated to QUIC along
with any final handshake octets that TLS needs to send. TLS also with any final handshake octets that TLS needs to send. TLS also
provides QUIC with the transport parameters that the peer advertised provides QUIC with the transport parameters that the peer advertised
during the handshake. during the handshake.
Once the handshake is complete, TLS becomes passive. TLS can still Once the handshake is complete, TLS becomes passive. TLS can still
receive data from its peer and respond in kind, but it will not need receive data from its peer and respond in kind, but it will not need
to send more data unless specifically requested - either by an to send more data unless specifically requested - either by an
application or QUIC. One reason to send data is that the server application or QUIC. One reason to send data is that the server
might wish to provide additional or updated session tickets to a might wish to provide additional or updated session tickets to a
client. client.
When the handshake is complete, QUIC only needs to provide TLS with When the handshake is complete, QUIC only needs to provide TLS with
any data that arrives on stream 1. In the same way that is done any data that arrives on stream 0. In the same way that is done
during the handshake, new data is requested from TLS after providing during the handshake, new data is requested from TLS after providing
received data. received data.
Important: Until the handshake is reported as complete, the Important: Until the handshake is reported as complete, the
connection and key exchange are not properly authenticated at the connection and key exchange are not properly authenticated at the
server. Even though 1-RTT keys are available to a server after server. Even though 1-RTT keys are available to a server after
receiving the first handshake messages from a client, the server receiving the first handshake messages from a client, the server
cannot consider the client to be authenticated until it receives cannot consider the client to be authenticated until it receives
and validates the client's Finished message. and validates the client's Finished message.
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o abort the connection. o abort the connection.
If QUIC requests source address validation, it also provides a new If QUIC requests source address validation, it also provides a new
address validation token. TLS includes that along with any address validation token. TLS includes that along with any
information it requires in the cookie extension of a TLS information it requires in the cookie extension of a TLS
HelloRetryRequest message. In the other cases, the connection either HelloRetryRequest message. In the other cases, the connection either
proceeds or terminates with a handshake error. proceeds or terminates with a handshake error.
The client echoes the cookie extension in a second ClientHello. A The client echoes the cookie extension in a second ClientHello. A
ClientHello that contains a valid cookie extension will be always be ClientHello that contains a valid cookie extension will always be in
in response to a HelloRetryRequest. If address validation was response to a HelloRetryRequest. If address validation was requested
requested by QUIC, then this will include an address validation by QUIC, then this will include an address validation token. TLS
token. TLS makes a second address validation request of QUIC, makes a second address validation request of QUIC, including the
including the value extracted from the cookie extension. In response value extracted from the cookie extension. In response to this
to this request, QUIC cannot ask for client address validation, it request, QUIC cannot ask for client address validation, it can only
can only abort or permit the connection attempt to proceed. abort or permit the connection attempt to proceed.
QUIC can provide a new address validation token for use in session QUIC can provide a new address validation token for use in session
resumption at any time after the handshake is complete. Each time a resumption at any time after the handshake is complete. Each time a
new token is provided TLS generates a NewSessionTicket message, with new token is provided TLS generates a NewSessionTicket message, with
the token included in the ticket. the token included in the ticket.
See Section 7 for more details on client address validation. See Section 8 for more details on client address validation.
4.2.3. Key Ready Events 4.2.3. Key Ready Events
TLS provides QUIC with signals when 0-RTT and 1-RTT keys are ready TLS provides QUIC with signals when 0-RTT and 1-RTT keys are ready
for use. These events are not asynchronous, they always occur for use. These events are not asynchronous, they always occur
immediately after TLS is provided with new handshake octets, or after immediately after TLS is provided with new handshake octets, or after
TLS produces handshake octets. TLS produces handshake octets.
When TLS completed its handshake, 1-RTT keys can be provided to QUIC. When TLS completed its handshake, 1-RTT keys can be provided to QUIC.
On both client and server, this occurs after sending the TLS Finished On both client and server, this occurs after sending the TLS Finished
skipping to change at page 13, line 47 skipping to change at page 13, line 23
acceptable provided that the features of TLS 1.3 that are used by acceptable provided that the features of TLS 1.3 that are used by
QUIC are supported by the newer version. QUIC are supported by the newer version.
A badly configured TLS implementation could negotiate TLS 1.2 or A badly configured TLS implementation could negotiate TLS 1.2 or
another older version of TLS. An endpoint MUST terminate the another older version of TLS. An endpoint MUST terminate the
connection if a version of TLS older than 1.3 is negotiated. connection if a version of TLS older than 1.3 is negotiated.
4.4. ClientHello Size 4.4. ClientHello Size
QUIC requires that the initial handshake packet from a client fit QUIC requires that the initial handshake packet from a client fit
within a single packet of at least 1280 octets. With framing and within the payload of a single packet. The size limits on QUIC
packet overheads this value could be reduced. packets mean that a record containing a ClientHello needs to fit
within 1197 octets.
A TLS ClientHello can fit within this limit with ample space A TLS ClientHello can fit within this limit with ample space
remaining. However, there are several variables that could cause remaining. However, there are several variables that could cause
this limit to be exceeded. Implementations are reminded that large this limit to be exceeded. Implementations are reminded that large
session tickets or HelloRetryRequest cookies, multiple or large key session tickets or HelloRetryRequest cookies, multiple or large key
shares, and long lists of supported ciphers, signature algorithms, shares, and long lists of supported ciphers, signature algorithms,
versions, QUIC transport parameters, and other negotiable parameters versions, QUIC transport parameters, and other negotiable parameters
and extensions could cause this message to grow. and extensions could cause this message to grow.
For servers, the size of the session tickets and HelloRetryRequest For servers, the size of the session tickets and HelloRetryRequest
cookie extension can have an effect on a client's ability to connect. cookie extension can have an effect on a client's ability to connect.
Choosing a small value increases the probability that these values Choosing a small value increases the probability that these values
can be successfully used by a client. can be successfully used by a client.
A TLS implementation does not need to enforce this size constraint. The TLS implementation does not need to ensure that the ClientHello
QUIC padding can be used to reach this size, meaning that a TLS is sufficiently large. QUIC PADDING frames are added to increase the
server is unlikely to receive a large ClientHello message. size of the packet as necessary.
4.5. Peer Authentication 4.5. Peer Authentication
The requirements for authentication depend on the application The requirements for authentication depend on the application
protocol that is in use. TLS provides server authentication and protocol that is in use. TLS provides server authentication and
permits the server to request client authentication. permits the server to request client authentication.
A client MUST authenticate the identity of the server. This A client MUST authenticate the identity of the server. This
typically involves verification that the identity of the server is typically involves verification that the identity of the server is
included in a certificate and that the certificate is issued by a included in a certificate and that the certificate is issued by a
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handshake. A server MAY refuse a connection if the client is unable handshake. A server MAY refuse a connection if the client is unable
to authenticate when requested. The requirements for client to authenticate when requested. The requirements for client
authentication vary based on application protocol and deployment. authentication vary based on application protocol and deployment.
A server MUST NOT use post-handshake client authentication (see A server MUST NOT use post-handshake client authentication (see
Section 4.6.2 of [I-D.ietf-tls-tls13]). Section 4.6.2 of [I-D.ietf-tls-tls13]).
4.6. TLS Errors 4.6. TLS Errors
Errors in the TLS connection SHOULD be signaled using TLS alerts on Errors in the TLS connection SHOULD be signaled using TLS alerts on
stream 1. A failure in the handshake MUST be treated as a QUIC stream 0. A failure in the handshake MUST be treated as a QUIC
connection error of type TLS_HANDSHAKE_FAILED. Once the handshake is connection error of type TLS_HANDSHAKE_FAILED. Once the handshake is
complete, an error in the TLS connection that causes a TLS alert to complete, an error in the TLS connection that causes a TLS alert to
be sent or received MUST be treated as a QUIC connection error of be sent or received MUST be treated as a QUIC connection error of
type TLS_FATAL_ALERT_GENERATED or TLS_FATAL_ALERT_RECEIVED type TLS_FATAL_ALERT_GENERATED or TLS_FATAL_ALERT_RECEIVED
respectively. respectively.
5. QUIC Packet Protection 5. QUIC Packet Protection
QUIC packet protection provides authenticated encryption of packets. QUIC packet protection provides authenticated encryption of packets.
This provides confidentiality and integrity protection for the This provides confidentiality and integrity protection for the
content of packets (see Section 5.3). Packet protection uses keys content of packets (see Section 5.3). Packet protection uses keys
that are exported from the TLS connection (see Section 5.2). that are exported from the TLS connection (see Section 5.2).
Different keys are used for QUIC packet protection and TLS record Different keys are used for QUIC packet protection and TLS record
protection. Having separate QUIC and TLS record protection means protection. TLS handshake messages are protected solely with TLS
that TLS records can be protected by two different keys. This record protection, but post-handshake messages are redundantly
redundancy is limited to only a few TLS records, and is maintained proteted with both both the QUIC packet protection and the TLS record
for the sake of simplicity. protection. These messages are limited in number, and so the
additional overhead is small.
5.1. Installing New Keys 5.1. Installing New Keys
As TLS reports the availability of keying material, the packet As TLS reports the availability of keying material, the packet
protection keys and initialization vectors (IVs) are updated (see protection keys and initialization vectors (IVs) are updated (see
Section 5.2). The selection of AEAD function is also updated to Section 5.2). The selection of AEAD function is also updated to
match the AEAD negotiated by TLS. match the AEAD negotiated by TLS.
For packets other than any unprotected handshake packets (see For packets other than any unprotected handshake packets (see
Section 6.1), once a change of keys has been made, packets with Section 7.1), once a change of keys has been made, packets with
higher packet numbers MUST use the new keying material. The higher packet numbers MUST be sent with the new keying material. The
KEY_PHASE bit on these packets is inverted each time new keys are KEY_PHASE bit on these packets is inverted each time new keys are
installed to signal the use of the new keys to the recipient (see installed to signal the use of the new keys to the recipient (see
Section 6 for details). Section 7 for details).
An endpoint retransmits stream data in a new packet. New packets An endpoint retransmits stream data in a new packet. New packets
have new packet numbers and use the latest packet protection keys. have new packet numbers and use the latest packet protection keys.
This simplifies key management when there are key updates (see This simplifies key management when there are key updates (see
Section 6.2). Section 7.2).
5.2. QUIC Key Expansion 5.2. QUIC Key Expansion
QUIC uses a system of packet protection secrets, keys and IVs that QUIC uses a system of packet protection secrets, keys and IVs that
are modelled on the system used in TLS [I-D.ietf-tls-tls13]. The are modelled on the system used in TLS [I-D.ietf-tls-tls13]. The
secrets that QUIC uses as the basis of its key schedule are obtained secrets that QUIC uses as the basis of its key schedule are obtained
using TLS exporters (see Section 7.3.3 of [I-D.ietf-tls-tls13]). using TLS exporters (see Section 7.5 of [I-D.ietf-tls-tls13]).
QUIC uses HKDF with the same hash function negotiated by TLS for key QUIC uses HKDF with the same hash function negotiated by TLS for key
derivation. For example, if TLS is using the TLS_AES_128_GCM_SHA256, derivation. For example, if TLS is using the TLS_AES_128_GCM_SHA256,
the SHA-256 hash function is used. the SHA-256 hash function is used.
5.2.1. 0-RTT Secret 5.2.1. 0-RTT Secret
0-RTT keys are those keys that are used in resumed connections prior 0-RTT keys are those keys that are used in resumed connections prior
to the completion of the TLS handshake. Data sent using 0-RTT keys to the completion of the TLS handshake. Data sent using 0-RTT keys
might be replayed and so has some restrictions on its use, see might be replayed and so has some restrictions on its use, see
Section 8.2. 0-RTT keys are used after sending or receiving a Section 9.2. 0-RTT keys are used after sending or receiving a
ClientHello. ClientHello.
The secret is exported from TLS using the exporter label "EXPORTER- The secret is exported from TLS using the exporter label "EXPORTER-
QUIC 0-RTT Secret" and an empty context. The size of the secret MUST QUIC 0-RTT Secret" and an empty context. The size of the secret MUST
be the size of the hash output for the PRF hash function negotiated be the size of the hash output for the PRF hash function negotiated
by TLS. This uses the TLS early_exporter_secret. The QUIC 0-RTT by TLS. This uses the TLS early_exporter_secret. The QUIC 0-RTT
secret is only used for protection of packets sent by the client. secret is only used for protection of packets sent by the client.
client_0rtt_secret client_0rtt_secret
= TLS-Exporter("EXPORTER-QUIC 0-RTT Secret" = TLS-Exporter("EXPORTER-QUIC 0-RTT Secret"
skipping to change at page 16, line 39 skipping to change at page 16, line 15
client_pp_secret_0 client_pp_secret_0
= TLS-Exporter("EXPORTER-QUIC client 1-RTT Secret" = TLS-Exporter("EXPORTER-QUIC client 1-RTT Secret"
"", Hash.length) "", Hash.length)
server_pp_secret_0 server_pp_secret_0
= TLS-Exporter("EXPORTER-QUIC server 1-RTT Secret" = TLS-Exporter("EXPORTER-QUIC server 1-RTT Secret"
"", Hash.length) "", Hash.length)
These secrets are used to derive the initial client and server packet These secrets are used to derive the initial client and server packet
protection keys. protection keys.
After a key update (see Section 6.2), these secrets are updated using After a key update (see Section 7.2), these secrets are updated using
the HKDF-Expand-Label function defined in Section 7.1 of the HKDF-Expand-Label function defined in Section 7.1 of
[I-D.ietf-tls-tls13]. HKDF-Expand-Label uses the PRF hash function [I-D.ietf-tls-tls13]. HKDF-Expand-Label uses the PRF hash function
negotiated by TLS. The replacement secret is derived using the negotiated by TLS. The replacement secret is derived using the
existing Secret, a Label of "QUIC client 1-RTT Secret" for the client existing Secret, a Label of "QUIC client 1-RTT Secret" for the client
and "QUIC server 1-RTT Secret" for the server, an empty HashValue, and "QUIC server 1-RTT Secret" for the server, an empty HashValue,
and the same output Length as the hash function selected by TLS for and the same output Length as the hash function selected by TLS for
its PRF. its PRF.
client_pp_secret_<N+1> client_pp_secret_<N+1>
= HKDF-Expand-Label(client_pp_secret_<N>, = HKDF-Expand-Label(client_pp_secret_<N>,
"QUIC client 1-RTT Secret", "QUIC client 1-RTT Secret",
"", Hash.length) "", Hash.length)
server_pp_secret_<N+1> server_pp_secret_<N+1>
= HKDF-Expand-Label(server_pp_secret_<N>, = HKDF-Expand-Label(server_pp_secret_<N>,
"QUIC server 1-RTT Secret", "QUIC server 1-RTT Secret",
"", Hash.length) "", Hash.length)
This allows for a succession of new secrets to be created as needed. This allows for a succession of new secrets to be created as needed.
HKDF-Expand-Label uses HKDF-Expand [RFC5869] with a specially HKDF-Expand-Label uses HKDF-Expand [RFC5869] with a specially
formatted info parameter. The info parameter that includes the formatted info parameter, as shown:
output length (in this case, the size of the PRF hash output) encoded
on two octets in network byte order, the length of the prefixed Label HKDF-Expand-Label(Secret, Label, HashValue, Length) =
as a single octet, the value of the Label prefixed with "TLS 1.3, ", HKDF-Expand(Secret, HkdfLabel, Length)
and a zero octet to indicate an empty HashValue. For example, the
client packet protection secret uses an info parameter of: Where HkdfLabel is specified as:
struct {
uint16 length = Length;
opaque label<10..255> = "TLS 1.3, " + Label;
uint8 hashLength; // Always 0
} HkdfLabel;
For example, the client packet protection secret uses an info
parameter of:
info = (HashLen / 256) || (HashLen % 256) || 0x21 || info = (HashLen / 256) || (HashLen % 256) || 0x21 ||
"TLS 1.3, QUIC client 1-RTT secret" || 0x00 "TLS 1.3, QUIC client 1-RTT secret" || 0x00
5.2.3. Packet Protection Key and IV 5.2.3. Packet Protection Key and IV
The complete key expansion uses an identical process for key The complete key expansion uses an identical process for key
expansion as defined in Section 7.3 of [I-D.ietf-tls-tls13], using expansion as defined in Section 7.3 of [I-D.ietf-tls-tls13], using
different values for the input secret. QUIC uses the AEAD function different values for the input secret. QUIC uses the AEAD function
negotiated by TLS. negotiated by TLS.
The packet protection key and IV used to protect the 0-RTT packets The packet protection key and IV used to protect the 0-RTT packets
sent by a client use the QUIC 0-RTT secret. This uses the HKDF- sent by a client are derived from the QUIC 0-RTT secret. The packet
Expand-Label with the PRF hash function negotiated by TLS. protection keys and IVs for 1-RTT packets sent by the client and
server are derived from the current generation of client_pp_secret
The length of the output is determined by the requirements of the and server_pp_secret respectively. The length of the output is
AEAD function selected by TLS. The key length is the AEAD key size. determined by the requirements of the AEAD function selected by TLS.
As defined in Section 5.3 of [I-D.ietf-tls-tls13], the IV length is The key length is the AEAD key size. As defined in Section 5.3 of
the larger of 8 or N_MIN (see Section 4 of [RFC5116]). [I-D.ietf-tls-tls13], the IV length is the larger of 8 or N_MIN (see
Section 4 of [RFC5116]). For any secret S, the corresponding key and
client_0rtt_key = HKDF-Expand-Label(client_0rtt_secret, IV are derived as shown below:
"key", "", key_length)
client_0rtt_iv = HKDF-Expand-Label(client_0rtt_secret,
"iv", "", iv_length)
Similarly, the packet protection key and IV used to protect 1-RTT
packets sent by both client and server use the current packet
protection secret.
client_pp_key_<N> = HKDF-Expand-Label(client_pp_secret_<N>,
"key", "", key_length)
client_pp_iv_<N> = HKDF-Expand-Label(client_pp_secret_<N>,
"iv", "", iv_length)
server_pp_key_<N> = HKDF-Expand-Label(server_pp_secret_<N>,
"key", "", key_length)
server_pp_iv_<N> = HKDF-Expand-Label(server_pp_secret_<N>,
"iv", "", iv_length)
The client protects (or encrypts) packets with the client packet key = HKDF-Expand-Label(S, "key", "", key_length)
protection key and IV; the server protects packets with the server iv = HKDF-Expand-Label(S, "iv", "", iv_length)
packet protection key.
The QUIC record protection initially starts without keying material. The QUIC record protection initially starts without keying material.
When the TLS state machine reports that the ClientHello has been When the TLS state machine reports that the ClientHello has been
sent, the 0-RTT keys can be generated and installed for writing. sent, the 0-RTT keys can be generated and installed for writing.
When the TLS state machine reports completion of the handshake, the When the TLS state machine reports completion of the handshake, the
1-RTT keys can be generated and installed for writing. 1-RTT keys can be generated and installed for writing.
5.3. QUIC AEAD Usage 5.3. QUIC AEAD Usage
The Authentication Encryption with Associated Data (AEAD) [RFC5116] The Authentication Encryption with Associated Data (AEAD) [RFC5116]
function used for QUIC packet protection is AEAD that is negotiated function used for QUIC packet protection is AEAD that is negotiated
for use with the TLS connection. For example, if TLS is using the for use with the TLS connection. For example, if TLS is using the
TLS_AES_128_GCM_SHA256, the AEAD_AES_128_GCM function is used. TLS_AES_128_GCM_SHA256, the AEAD_AES_128_GCM function is used.
Regular QUIC packets are protected by an AEAD [RFC5116]. Version Regular QUIC packets are protected by an AEAD algorithm [RFC5116].
negotiation and public reset packets are not protected. Version negotiation and public reset packets are not protected.
Once TLS has provided a key, the contents of regular QUIC packets Once TLS has provided a key, the contents of regular QUIC packets
immediately after any TLS messages have been sent are protected by immediately after any TLS messages have been sent are protected by
the AEAD selected by TLS. the AEAD selected by TLS.
The key, K, for the AEAD is either the client packet protection key The key, K, is either the client packet protection key
(client_pp_key_n) or the server packet protection key (client_pp_key_n) or the server packet protection key
(server_pp_key_n), derived as defined in Section 5.2. (server_pp_key_n), derived as defined in Section 5.2.
The nonce, N, for the AEAD is formed by combining either the packet The nonce, N, is formed by combining the packet protection IV (either
protection IV (either client_pp_iv_n or server_pp_iv_n) with packet client_pp_iv_n or server_pp_iv_n) with the packet number. The 64
numbers. The 64 bits of the reconstructed QUIC packet number in bits of the reconstructed QUIC packet number in network byte order is
network byte order is left-padded with zeros to the size of the IV. left-padded with zeros to the size of the IV. The exclusive OR of
The exclusive OR of the padded packet number and the IV forms the the padded packet number and the IV forms the AEAD nonce.
AEAD nonce.
The associated data, A, for the AEAD is the contents of the QUIC The associated data, A, for the AEAD is the contents of the QUIC
header, starting from the flags octet in the common header. header, starting from the flags octet in the common header.
The input plaintext, P, for the AEAD is the contents of the QUIC The input plaintext, P, for the AEAD is the contents of the QUIC
frame following the packet number, as described in [QUIC-TRANSPORT]. frame following the packet number, as described in [QUIC-TRANSPORT].
The output ciphertext, C, of the AEAD is transmitted in place of P. The output ciphertext, C, of the AEAD is transmitted in place of P.
Prior to TLS providing keys, no record protection is performed and Prior to TLS providing keys, no record protection is performed and
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attacks where packets are dropped in other ways. QUIC is therefore attacks where packets are dropped in other ways. QUIC is therefore
not affected by this form of truncation. not affected by this form of truncation.
The QUIC packet number is not reset and it is not permitted to go The QUIC packet number is not reset and it is not permitted to go
higher than its maximum value of 2^64-1. This establishes a hard higher than its maximum value of 2^64-1. This establishes a hard
limit on the number of packets that can be sent. limit on the number of packets that can be sent.
Some AEAD functions have limits for how many packets can be encrypted Some AEAD functions have limits for how many packets can be encrypted
under the same key and IV (see for example [AEBounds]). This might under the same key and IV (see for example [AEBounds]). This might
be lower than the packet number limit. An endpoint MUST initiate a be lower than the packet number limit. An endpoint MUST initiate a
key update (Section 6.2) prior to exceeding any limit set for the key update (Section 7.2) prior to exceeding any limit set for the
AEAD that is in use. AEAD that is in use.
TLS maintains a separate sequence number that is used for record TLS maintains a separate sequence number that is used for record
protection on the connection that is hosted on stream 1. This protection on the connection that is hosted on stream 0. This
sequence number is not visible to QUIC. sequence number is not visible to QUIC.
5.5. Receiving Protected Packets 5.5. Receiving Protected Packets
Once an endpoint successfully receives a packet with a given packet Once an endpoint successfully receives a packet with a given packet
number, it MUST discard all packets with higher packet numbers if number, it MUST discard all packets with higher packet numbers if
they cannot be successfully unprotected with either the same key, or they cannot be successfully unprotected with either the same key, or
- if there is a key update - the next packet protection key (see - if there is a key update - the next packet protection key (see
Section 6.2). Similarly, a packet that appears to trigger a key Section 7.2). Similarly, a packet that appears to trigger a key
update, but cannot be unprotected successfully MUST be discarded. update, but cannot be unprotected successfully MUST be discarded.
Failure to unprotect a packet does not necessarily indicate the Failure to unprotect a packet does not necessarily indicate the
existence of a protocol error in a peer or an attack. The truncated existence of a protocol error in a peer or an attack. The truncated
packet number encoding used in QUIC can cause packet numbers to be packet number encoding used in QUIC can cause packet numbers to be
decoded incorrectly if they are delayed significantly. decoded incorrectly if they are delayed significantly.
6. Key Phases 5.6. Packet Number Gaps
[QUIC-TRANSPORT]; Section 7.5.1.1 also requires a secret to compute
packet number gaps on connection ID transitions. That secret is
computed as:
packet_number_secret
= TLS-Exporter("EXPORTER-QUIC Packet Number Secret"
"", Hash.length)
6. Unprotected Packets
QUIC adds an integrity check to all unprotected packets. Any packet
that is not protected by the negotiated AEAD (see Section 5),
includes an integrity check. This check does not prevent the packet
from being altered, it exists for added resilience against data
corruption and to provided added assurance that the sender intends to
use QUIC.
Unprotected packets all use the long form of the QUIC header and so
will include a version number. For this version of QUIC, the
integrity check uses the 64-bit FNV-1a hash (see Section 6.2). The
output of this hash is appended to the payload of the packet.
The integrity check algorithm MAY change for other versions of the
protocol.
6.1. Integrity Check Processing
An endpoint sending a packet that has a long header and a type that
does not indicate that the packet will be protected (that is, 0-RTT
Encrypted (0x05), 1-RTT Encrypted (key phase 0) (0x06), or 1-RTT
Encrypted (key phase 1) (0x07)) first constructs the packet that it
sends without the integrity check.
The sender then calculates the integrity check over the entire
packet, starting from the type field. The output of the hash is
appended to the packet.
A receiver that receives an unprotected packet first checks that the
version is correct, then removes the trailing 8 octets. It
calculates the integrity check over the remainder of the packet.
Unprotected packets that do not contain a valid integrity check MUST
be discarded.
6.2. The 64-bit FNV-1a Algorithm
QUIC uses the 64-bit version of the alternative Fowler/Noll/Vo hash
(FNV-1a) [FNV].
FNV-1a can be expressed in pseudocode as:
"hash := offset basis for each input octet: hash := hash XOR input
octet hash := hash * prime "
That is, a 64-bit unsigned integer is initialized with an offset
basis. Then, for each octet of the input, the exclusive binary OR of
the value is taken, then multiplied by a prime. Any overflow from
multiplication is discarded.
The offset basis for the 64-bit FNV-1a is the decimal value
14695981039346656037 (in hex, 0xcbf29ce484222325). The prime is
1099511628211 (in hex, 0x100000001b3; or as an expression 2^40 + 2^8
+ 0xb3).
Once all octets have been processed in this fashion, the final
integer value is encoded as 8 octets in network byte order.
7. Key Phases
As TLS reports the availability of 0-RTT and 1-RTT keys, new keying As TLS reports the availability of 0-RTT and 1-RTT keys, new keying
material can be exported from TLS and used for QUIC packet material can be exported from TLS and used for QUIC packet
protection. At each transition during the handshake a new secret is protection. At each transition during the handshake a new secret is
exported from TLS and packet protection keys are derived from that exported from TLS and packet protection keys are derived from that
secret. secret.
Every time that a new set of keys is used for protecting outbound Every time that a new set of keys is used for protecting outbound
packets, the KEY_PHASE bit in the public flags is toggled. The packets, the KEY_PHASE bit in the public flags is toggled. 0-RTT
exception is the transition from 0-RTT keys to 1-RTT keys, where the protected packets use the QUIC long header, they do not use the
presence of the version field and its associated bit is used (see KEY_PHASE bit to select the correct keys (see Section 7.1.1).
Section 6.1.1).
Once the connection is fully enabled, the KEY_PHASE bit allows a Once the connection is fully enabled, the KEY_PHASE bit allows a
recipient to detect a change in keying material without necessarily recipient to detect a change in keying material without necessarily
needing to receive the first packet that triggered the change. An needing to receive the first packet that triggered the change. An
endpoint that notices a changed KEY_PHASE bit can update keys and endpoint that notices a changed KEY_PHASE bit can update keys and
decrypt the packet that contains the changed bit, see Section 6.2. decrypt the packet that contains the changed bit, see Section 7.2.
The KEY_PHASE bit is the third bit of the public flags (0x04). The KEY_PHASE bit is included as the 0x20 bit of the QUIC short
header, or is determined by the packet type from the long header (a
type of 0x06 indicates a key phase of 0, 0x07 indicates key phase 1).
Transitions between keys during the handshake are complicated by the Transitions between keys during the handshake are complicated by the
need to ensure that TLS handshake messages are sent with the correct need to ensure that TLS handshake messages are sent with the correct
packet protection. packet protection.
6.1. Packet Protection for the TLS Handshake 7.1. Packet Protection for the TLS Handshake
The initial exchange of packets are sent without protection. These The initial exchange of packets are sent without protection. These
packets are marked with a KEY_PHASE of 0. packets use a cleartext packet type.
TLS handshake messages MUST NOT be protected using QUIC packet TLS handshake messages MUST NOT be protected using QUIC packet
protection. A KEY_PHASE of 0 is used for all of these packets, even protection. All TLS handshake messages up to the TLS Finished
during retransmission. The messages affected are all TLS handshake message sent by either endpoint use cleartext packets.
message up to the TLS Finished that is sent by each endpoint.
Any TLS handshake messages that are sent after completing the TLS Any TLS handshake messages that are sent after completing the TLS
handshake do not need special packet protection rules. Packets handshake do not need special packet protection rules. Packets
containing these messages use the packet protection keys that are containing these messages use the packet protection keys that are
current at the time of sending (or retransmission). current at the time of sending (or retransmission).
Like the client, a server MUST send retransmissions of its Like the client, a server MUST send retransmissions of its
unprotected handshake messages or acknowledgments for unprotected unprotected handshake messages or acknowledgments for unprotected
handshake messages sent by the client in unprotected packets handshake messages sent by the client in cleartext packets.
(KEY_PHASE=0).
6.1.1. Initial Key Transitions 7.1.1. Initial Key Transitions
Once the TLS handshake is complete, keying material is exported from Once the TLS handshake is complete, keying material is exported from
TLS and QUIC packet protection commences. TLS and QUIC packet protection commences.
Packets protected with 1-RTT keys have a KEY_PHASE bit set to 1. Packets protected with 1-RTT keys initially have a KEY_PHASE bit set
These packets also have a VERSION bit set to 0. to 0. This bit inverts with each subsequent key update (see
Section 7.2).
If the client sends 0-RTT data, it marks packets protected with 0-RTT
keys with a KEY_PHASE of 1 and a VERSION bit of 1. Setting the
version bit means that all packets also include the version field.
The client retains the VERSION bit, but reverts the KEY_PHASE bit for
the packet that contains the TLS EndOfEarlyData and Finished
messages.
The client clears the VERSION bit and sets the KEY_PHASE bit to 1
when it transitions to using 1-RTT keys.
Marking 0-RTT data with the both KEY_PHASE and VERSION bits ensures If the client sends 0-RTT data, it uses the 0-RTT packet type. The
that the server is able to identify these packets as 0-RTT data in packet that contains the TLS EndOfEarlyData and Finished messages are
case packets containing TLS handshake message are lost or delayed. sent in cleartext packets.
Including the version also ensures that the packet format is known to
the server in this case.
Using both KEY_PHASE and VERSION also ensures that the server is able Using distinct packet types during the handshake for handshake
to distinguish between cleartext handshake packets (KEY_PHASE=0, messages, 0-RTT data, and 1-RTT data ensures that the server is able
VERSION=1), 0-RTT protected packets (KEY_PHASE=1, VERSION=1), and to distinguish between the different keys used to remove packet
1-RTT protected packets (KEY_PHASE=1, VERSION=0). Packets with all protection. All of these packets can arrive concurrently at a
of these markings can arrive concurrently, and being able to identify server.
each cleanly ensures that the correct packet protection keys can be
selected and applied.
A server might choose to retain 0-RTT packets that arrive before a A server might choose to retain 0-RTT packets that arrive before a
TLS ClientHello. The server can then use those packets once the TLS ClientHello. The server can then use those packets once the
ClientHello arrives. However, the potential for denial of service ClientHello arrives. However, the potential for denial of service
from buffering 0-RTT packets is significant. These packets cannot be from buffering 0-RTT packets is significant. These packets cannot be
authenticated and so might be employed by an attacker to exhaust authenticated and so might be employed by an attacker to exhaust
server resources. Limiting the number of packets that are saved server resources. Limiting the number of packets that are saved
might be necessary. might be necessary.
The server transitions to using 1-RTT keys after sending its first The server transitions to using 1-RTT keys after sending its first
flight of TLS handshake messages. From this point, the server flight of TLS handshake messages. From this point, the server
protects all packets with 1-RTT keys. Future packets are therefore protects all packets with 1-RTT keys. Future packets are therefore
protected with 1-RTT keys and marked with a KEY_PHASE of 1. protected with 1-RTT keys. Initially, these are marked with a
KEY_PHASE of 0.
6.1.2. Retransmission and Acknowledgment of Unprotected Packets 7.1.2. Retransmission and Acknowledgment of Unprotected Packets
TLS handshake messages from both client and server are critical to TLS handshake messages from both client and server are critical to
the key exchange. The contents of these messages determines the keys the key exchange. The contents of these messages determines the keys
used to protect later messages. If these handshake messages are used to protect later messages. If these handshake messages are
included in packets that are protected with these keys, they will be included in packets that are protected with these keys, they will be
indecipherable to the recipient. indecipherable to the recipient.
Even though newer keys could be available when retranmitting, Even though newer keys could be available when retransmitting,
retransmissions of these handshake messages MUST be sent in retransmissions of these handshake messages MUST be sent in cleartext
unprotected packets (with a KEY_PHASE of 0). An endpoint MUST also packets. An endpoint MUST generate ACK frames for these messages and
generate ACK frames for these messages that are sent in unprotected send them in cleartext packets.
packets.
A HelloRetryRequest handshake message might be used to reject an A HelloRetryRequest handshake message might be used to reject an
initial ClientHello. A HelloRetryRequest handshake message and any initial ClientHello. A HelloRetryRequest handshake message is sent
second ClientHello that is sent in response MUST also be sent without in a Server Stateless Retry packet; any second ClientHello that is
packet protection. This is natural, because no new keying material sent in response uses a Client Initial packet type. Neither packet
will be available when these messages need to be sent. Upon receipt is protected. This is natural, because no new keying material will
of a HelloRetryRequest, a client SHOULD cease any transmission of be available when these messages need to be sent. Upon receipt of a
0-RTT data; 0-RTT data will only be discarded by any server that HelloRetryRequest, a client SHOULD cease any transmission of 0-RTT
sends a HelloRetryRequest. data; 0-RTT data will only be discarded by any server that sends a
HelloRetryRequest.
The KEY_PHASE and VERSION bits ensure that protected packets are The packet type ensures that protected packets are clearly
clearly distinguished from unprotected packets. Loss or reordering distinguished from unprotected packets. Loss or reordering might
might cause unprotected packets to arrive once 1-RTT keys are in use, cause unprotected packets to arrive once 1-RTT keys are in use,
unprotected packets are easily distinguished from 1-RTT packets. unprotected packets are easily distinguished from 1-RTT packets using
the packet type.
Once 1-RTT keys are available to an endpoint, it no longer needs the Once 1-RTT keys are available to an endpoint, it no longer needs the
TLS handshake messages that are carried in unprotected packets. TLS handshake messages that are carried in unprotected packets.
However, a server might need to retransmit its TLS handshake messages However, a server might need to retransmit its TLS handshake messages
in response to receiving an unprotected packet that contains ACK in response to receiving an unprotected packet that contains ACK
frames. A server MUST process ACK frames in unprotected packets frames. A server MUST process ACK frames in unprotected packets
until the TLS handshake is reported as complete, or it receives an until the TLS handshake is reported as complete, or it receives an
ACK frame in a protected packet that acknowledges all of its ACK frame in a protected packet that acknowledges all of its
handshake messages. handshake messages.
To limit the number of key phases that could be active, an endpoint To limit the number of key phases that could be active, an endpoint
MUST NOT initiate a key update while there are any unacknowledged MUST NOT initiate a key update while there are any unacknowledged
handshake messages, see Section 6.2. handshake messages, see Section 7.2.
6.2. Key Update 7.2. Key Update
Once the TLS handshake is complete, the KEY_PHASE bit allows for Once the TLS handshake is complete, the KEY_PHASE bit allows for
refreshes of keying material by either peer. Endpoints start using refreshes of keying material by either peer. Endpoints start using
updated keys immediately without additional signaling; the change in updated keys immediately without additional signaling; the change in
the KEY_PHASE bit indicates that a new key is in use. the KEY_PHASE bit indicates that a new key is in use.
An endpoint MUST NOT initiate more than one key update at a time. A An endpoint MUST NOT initiate more than one key update at a time. A
new key cannot be used until the endpoint has received and new key cannot be used until the endpoint has received and
successfully decrypted a packet with a matching KEY_PHASE. Note that successfully decrypted a packet with a matching KEY_PHASE. Note that
when 0-RTT is attempted the value of the KEY_PHASE bit will be when 0-RTT is attempted the value of the KEY_PHASE bit will be
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messages. A client cannot initiate a key update until all of its messages. A client cannot initiate a key update until all of its
handshake messages have been acknowledged by the server. handshake messages have been acknowledged by the server.
A packet that triggers a key update could arrive after successfully A packet that triggers a key update could arrive after successfully
processing a packet with a higher packet number. This is only processing a packet with a higher packet number. This is only
possible if there is a key compromise and an attack, or if the peer possible if there is a key compromise and an attack, or if the peer
is incorrectly reverting to use of old keys. Because the latter is incorrectly reverting to use of old keys. Because the latter
cannot be differentiated from an attack, an endpoint MUST immediately cannot be differentiated from an attack, an endpoint MUST immediately
terminate the connection if it detects this condition. terminate the connection if it detects this condition.
7. Client Address Validation 8. Client Address Validation
Two tools are provided by TLS to enable validation of client source Two tools are provided by TLS to enable validation of client source
addresses at a server: the cookie in the HelloRetryRequest message, addresses at a server: the cookie in the HelloRetryRequest message,
and the ticket in the NewSessionTicket message. and the ticket in the NewSessionTicket message.
7.1. HelloRetryRequest Address Validation 8.1. HelloRetryRequest Address Validation
The cookie extension in the TLS HelloRetryRequest message allows a The cookie extension in the TLS HelloRetryRequest message allows a
server to perform source address validation during the handshake. server to perform source address validation during the handshake.
When QUIC requests address validation during the processing of the When QUIC requests address validation during the processing of the
first ClientHello, the token it provides is included in the cookie first ClientHello, the token it provides is included in the cookie
extension of a HelloRetryRequest. As long as the cookie cannot be extension of a HelloRetryRequest. As long as the cookie cannot be
successfully guessed by a client, the server can be assured that the successfully guessed by a client, the server can be assured that the
client received the HelloRetryRequest if it includes the value in a client received the HelloRetryRequest if it includes the value in a
second ClientHello. second ClientHello.
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If TLS needs to send a HelloRetryRequest for other reasons, it needs If TLS needs to send a HelloRetryRequest for other reasons, it needs
to ensure that it can correctly identify the reason that the to ensure that it can correctly identify the reason that the
HelloRetryRequest was generated. During the processing of a second HelloRetryRequest was generated. During the processing of a second
ClientHello, TLS does not need to consult the transport protocol ClientHello, TLS does not need to consult the transport protocol
regarding address validation if address validation was not requested regarding address validation if address validation was not requested
originally. In such cases, the cookie extension could either be originally. In such cases, the cookie extension could either be
absent or it could indicate that an address validation token is not absent or it could indicate that an address validation token is not
present. present.
7.2. NewSessionTicket Address Validation 8.1.1. Stateless Address Validation
A server can use the cookie extension to store all state necessary to
continue the connection. This allows a server to avoid committing
state for clients that have unvalidated source addresses.
For instance, a server could use a statically-configured key to
encrypt the information that it requires and include that information
in the cookie. In addition to address validation information, a
server that uses encryption also needs to be able recover the hash of
the ClientHello and its length, plus any information it needs in
order to reconstruct the HelloRetryRequest.
8.1.2. Sending HelloRetryRequest
A server does not need to maintain state for the connection when
sending a HelloRetryRequest message. This might be necessary to
avoid creating a denial of service exposure for the server. However,
this means that information about the transport will be lost at the
server. This includes the stream offset of stream 0, the packet
number that the server selects, and any opportunity to measure round
trip time.
A server MUST send a TLS HelloRetryRequest in a Server Stateless
Retry packet. Using a Server Stateless Retry packet causes the
client to reset stream offsets. It also avoids the need for the
server select an initial packet number, which would need to be
remembered so that subsequent packets could be correctly numbered.
A HelloRetryRequest message MUST NOT be split between multiple Server
Stateless Retry packets. This means that HelloRetryRequest is
subject to the same size constraints as a ClientHello (see
Section 4.4).
8.2. NewSessionTicket Address Validation
The ticket in the TLS NewSessionTicket message allows a server to The ticket in the TLS NewSessionTicket message allows a server to
provide a client with a similar sort of token. When a client resumes provide a client with a similar sort of token. When a client resumes
a TLS connection - whether or not 0-RTT is attempted - it includes a TLS connection - whether or not 0-RTT is attempted - it includes
the ticket in the handshake message. As with the HelloRetryRequest the ticket in the handshake message. As with the HelloRetryRequest
cookie, the server includes the address validation token in the cookie, the server includes the address validation token in the
ticket. TLS provides the token it extracts from the session ticket ticket. TLS provides the token it extracts from the session ticket
to the transport when it asks whether source address validation is to the transport when it asks whether source address validation is
needed. needed.
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A server can send a NewSessionTicket message at any time. This A server can send a NewSessionTicket message at any time. This
allows it to update the state - and the address validation token - allows it to update the state - and the address validation token -
that is included in the ticket. This might be done to refresh the that is included in the ticket. This might be done to refresh the
ticket or token, or it might be generated in response to changes in ticket or token, or it might be generated in response to changes in
the state of the connection. QUIC can request that a the state of the connection. QUIC can request that a
NewSessionTicket be sent by providing a new address validation token. NewSessionTicket be sent by providing a new address validation token.
A server that intends to support 0-RTT SHOULD provide an address A server that intends to support 0-RTT SHOULD provide an address
validation token immediately after completing the TLS handshake. validation token immediately after completing the TLS handshake.
7.3. Address Validation Token Integrity 8.3. Address Validation Token Integrity
TLS MUST provide integrity protection for address validation token TLS MUST provide integrity protection for address validation token
unless the transport guarantees integrity protection by other means. unless the transport guarantees integrity protection by other means.
For a NewSessionTicket that includes confidential information - such For a NewSessionTicket that includes confidential information - such
as the resumption secret - including the token under authenticated as the resumption secret - including the token under authenticated
encryption ensures that the token gains both confidentiality and encryption ensures that the token gains both confidentiality and
integrity protection without duplicating the overheads of that integrity protection without duplicating the overheads of that
protection. protection.
8. Pre-handshake QUIC Messages 9. Pre-handshake QUIC Messages
Implementations MUST NOT exchange data on any stream other than Implementations MUST NOT exchange data on any stream other than
stream 1 without packet protection. QUIC requires the use of several stream 0 without packet protection. QUIC requires the use of several
types of frame for managing loss detection and recovery during this types of frame for managing loss detection and recovery during this
phase. In addition, it might be useful to use the data acquired phase. In addition, it might be useful to use the data acquired
during the exchange of unauthenticated messages for congestion during the exchange of unauthenticated messages for congestion
control. control.
This section generally only applies to TLS handshake messages from This section generally only applies to TLS handshake messages from
both peers and acknowledgments of the packets carrying those both peers and acknowledgments of the packets carrying those
messages. In many cases, the need for servers to provide messages. In many cases, the need for servers to provide
acknowledgments is minimal, since the messages that clients send are acknowledgments is minimal, since the messages that clients send are
small and implicitly acknowledged by the server's responses. small and implicitly acknowledged by the server's responses.
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o discard and ignore them o discard and ignore them
o use them, but reset any state that is established once the o use them, but reset any state that is established once the
handshake completes handshake completes
o use them and authenticate them afterwards; failing the handshake o use them and authenticate them afterwards; failing the handshake
if they can't be authenticated if they can't be authenticated
o save them and use them when they can be properly authenticated o save them and use them when they can be properly authenticated
o treat them as a fatal error o treat them as a fatal error
Different strategies are appropriate for different types of data. Different strategies are appropriate for different types of data.
This document proposes that all strategies are possible depending on This document proposes that all strategies are possible depending on
the type of message. the type of message.
o Transport parameters are made usable and authenticated as part of o Transport parameters are made usable and authenticated as part of
the TLS handshake (see Section 9.2). the TLS handshake (see Section 10.2).
o Most unprotected messages are treated as fatal errors when o Most unprotected messages are treated as fatal errors when
received except for the small number necessary to permit the received except for the small number necessary to permit the
handshake to complete (see Section 8.1). handshake to complete (see Section 9.1).
o Protected packets can either be discarded or saved and later used o Protected packets can either be discarded or saved and later used
(see Section 8.3). (see Section 9.3).
8.1. Unprotected Packets Prior to Handshake Completion 9.1. Unprotected Packets Prior to Handshake Completion
This section describes the handling of messages that are sent and This section describes the handling of messages that are sent and
received prior to the completion of the TLS handshake. received prior to the completion of the TLS handshake.
Sending and receiving unprotected messages is hazardous. Unless Sending and receiving unprotected messages is hazardous. Unless
expressly permitted, receipt of an unprotected message of any kind expressly permitted, receipt of an unprotected message of any kind
MUST be treated as a fatal error. MUST be treated as a fatal error.
8.1.1. STREAM Frames 9.1.1. STREAM Frames
"STREAM" frames for stream 1 are permitted. These carry the TLS "STREAM" frames for stream 0 are permitted. These carry the TLS
handshake messages. Once 1-RTT keys are available, unprotected handshake messages. Once 1-RTT keys are available, unprotected
"STREAM" frames on stream 1 can be ignored. "STREAM" frames on stream 0 can be ignored.
Receiving unprotected "STREAM" frames for other streams MUST be Receiving unprotected "STREAM" frames for other streams MUST be
treated as a fatal error. treated as a fatal error.
8.1.2. ACK Frames 9.1.2. ACK Frames
"ACK" frames are permitted prior to the handshake being complete. "ACK" frames are permitted prior to the handshake being complete.
Information learned from "ACK" frames cannot be entirely relied upon, Information learned from "ACK" frames cannot be entirely relied upon,
since an attacker is able to inject these packets. Timing and packet since an attacker is able to inject these packets. Timing and packet
retransmission information from "ACK" frames is critical to the retransmission information from "ACK" frames is critical to the
functioning of the protocol, but these frames might be spoofed or functioning of the protocol, but these frames might be spoofed or
altered. altered.
Endpoints MUST NOT use an unprotected "ACK" frame to acknowledge data Endpoints MUST NOT use an unprotected "ACK" frame to acknowledge data
that was protected by 0-RTT or 1-RTT keys. An endpoint MUST ignore that was protected by 0-RTT or 1-RTT keys. An endpoint MUST ignore
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problem if the handshake completes without loss, but it could mean problem if the handshake completes without loss, but it could mean
that 0-RTT stalls when a handshake packet disappears for any that 0-RTT stalls when a handshake packet disappears for any
reason. reason.
An endpoint SHOULD use data from unprotected or 0-RTT-protected "ACK" An endpoint SHOULD use data from unprotected or 0-RTT-protected "ACK"
frames only during the initial handshake and while they have frames only during the initial handshake and while they have
insufficient information from 1-RTT-protected "ACK" frames. Once insufficient information from 1-RTT-protected "ACK" frames. Once
sufficient information has been obtained from protected messages, sufficient information has been obtained from protected messages,
information obtained from less reliable sources can be discarded. information obtained from less reliable sources can be discarded.
8.1.3. WINDOW_UPDATE Frames 9.1.3. Updates to Data and Stream Limits
"WINDOW_UPDATE" frames MUST NOT be sent unprotected. "MAX_DATA", "MAX_STREAM_DATA", "BLOCKED", "STREAM_BLOCKED", and
"MAX_STREAM_ID" frames MUST NOT be sent unprotected.
Though data is exchanged on stream 1, the initial flow control window Though data is exchanged on stream 0, the initial flow control window
is sufficiently large to allow the TLS handshake to complete. This on that stream is sufficiently large to allow the TLS handshake to
limits the maximum size of the TLS handshake and would prevent a complete. This limits the maximum size of the TLS handshake and
server or client from using an abnormally large certificate chain. would prevent a server or client from using an abnormally large
certificate chain.
Stream 1 is exempt from the connection-level flow control window. Stream 0 is exempt from the connection-level flow control window.
8.1.4. Denial of Service with Unprotected Packets Consequently, there is no need to signal being blocked on flow
control.
Similarly, there is no need to increase the number of allowed streams
until the handshake completes.
9.1.4. Denial of Service with Unprotected Packets
Accepting unprotected - specifically unauthenticated - packets Accepting unprotected - specifically unauthenticated - packets
presents a denial of service risk to endpoints. An attacker that is presents a denial of service risk to endpoints. An attacker that is
able to inject unprotected packets can cause a recipient to drop even able to inject unprotected packets can cause a recipient to drop even
protected packets with a matching sequence number. The spurious protected packets with a matching sequence number. The spurious
packet shadows the genuine packet, causing the genuine packet to be packet shadows the genuine packet, causing the genuine packet to be
ignored as redundant. ignored as redundant.
Once the TLS handshake is complete, both peers MUST ignore Once the TLS handshake is complete, both peers MUST ignore
unprotected packets. From that point onward, unprotected messages unprotected packets. From that point onward, unprotected messages
can be safely dropped. can be safely dropped.
Since only TLS handshake packets and acknowledgments are sent in the Since only TLS handshake packets and acknowledgments are sent in the
clear, an attacker is able to force implementations to rely on clear, an attacker is able to force implementations to rely on
retransmission for packets that are lost or shadowed. Thus, an retransmission for packets that are lost or shadowed. Thus, an
attacker that intends to deny service to an endpoint has to drop or attacker that intends to deny service to an endpoint has to drop or
shadow protected packets in order to ensure that their victim shadow protected packets in order to ensure that their victim
continues to accept unprotected packets. The ability to shadow continues to accept unprotected packets. The ability to shadow
packets means that an attacker does not need to be on path. packets means that an attacker does not need to be on path.
ISSUE: This would not be an issue if QUIC had a randomized starting
sequence number. If we choose to randomize, we fix this problem
and reduce the denial of service exposure to on-path attackers.
The only possible problem is in authenticating the initial value,
so that peers can be sure that they haven't missed an initial
message.
In addition to causing valid packets to be dropped, an attacker can In addition to causing valid packets to be dropped, an attacker can
generate packets with an intent of causing the recipient to expend generate packets with an intent of causing the recipient to expend
processing resources. See Section 10.2 for a discussion of these processing resources. See Section 11.2 for a discussion of these
risks. risks.
To avoid receiving TLS packets that contain no useful data, a TLS To avoid receiving TLS packets that contain no useful data, a TLS
implementation MUST reject empty TLS handshake records and any record implementation MUST reject empty TLS handshake records and any record
that is not permitted by the TLS state machine. Any TLS application that is not permitted by the TLS state machine. Any TLS application
data or alerts that is received prior to the end of the handshake data or alerts that is received prior to the end of the handshake
MUST be treated as a fatal error. MUST be treated as a fatal error.
8.2. Use of 0-RTT Keys 9.2. Use of 0-RTT Keys
If 0-RTT keys are available, the lack of replay protection means that If 0-RTT keys are available, the lack of replay protection means that
restrictions on their use are necessary to avoid replay attacks on restrictions on their use are necessary to avoid replay attacks on
the protocol. the protocol.
A client MUST only use 0-RTT keys to protect data that is idempotent. A client MUST only use 0-RTT keys to protect data that is idempotent.
A client MAY wish to apply additional restrictions on what data it A client MAY wish to apply additional restrictions on what data it
sends prior to the completion of the TLS handshake. A client sends prior to the completion of the TLS handshake. A client
otherwise treats 0-RTT keys as equivalent to 1-RTT keys. otherwise treats 0-RTT keys as equivalent to 1-RTT keys.
A client that receives an indication that its 0-RTT data has been A client that receives an indication that its 0-RTT data has been
accepted by a server can send 0-RTT data until it receives all of the accepted by a server can send 0-RTT data until it receives all of the
server's handshake messages. A client SHOULD stop sending 0-RTT data server's handshake messages. A client SHOULD stop sending 0-RTT data
if it receives an indication that 0-RTT data has been rejected. if it receives an indication that 0-RTT data has been rejected.
A server MUST NOT use 0-RTT keys to protect packets. A server MUST NOT use 0-RTT keys to protect packets.
8.3. Receiving Out-of-Order Protected Frames 9.3. Receiving Out-of-Order Protected Frames
Due to reordering and loss, protected packets might be received by an Due to reordering and loss, protected packets might be received by an
endpoint before the final TLS handshake messages are received. A endpoint before the final TLS handshake messages are received. A
client will be unable to decrypt 1-RTT packets from the server, client will be unable to decrypt 1-RTT packets from the server,
whereas a server will be able to decrypt 1-RTT packets from the whereas a server will be able to decrypt 1-RTT packets from the
client. client.
Packets protected with 1-RTT keys MAY be stored and later decrypted Packets protected with 1-RTT keys MAY be stored and later decrypted
and used once the handshake is complete. A server MUST NOT use 1-RTT and used once the handshake is complete. A server MUST NOT use 1-RTT
protected packets before verifying either the client Finished message protected packets before verifying either the client Finished message
skipping to change at page 30, line 17 skipping to change at page 31, line 10
A server could receive packets protected with 0-RTT keys prior to A server could receive packets protected with 0-RTT keys prior to
receiving a TLS ClientHello. The server MAY retain these packets for receiving a TLS ClientHello. The server MAY retain these packets for
later decryption in anticipation of receiving a ClientHello. later decryption in anticipation of receiving a ClientHello.
Receiving and verifying the TLS Finished message is critical in Receiving and verifying the TLS Finished message is critical in
ensuring the integrity of the TLS handshake. A server MUST NOT use ensuring the integrity of the TLS handshake. A server MUST NOT use
protected packets from the client prior to verifying the client protected packets from the client prior to verifying the client
Finished message if its response depends on client authentication. Finished message if its response depends on client authentication.
9. QUIC-Specific Additions to the TLS Handshake 10. QUIC-Specific Additions to the TLS Handshake
QUIC uses the TLS handshake for more than just negotiation of QUIC uses the TLS handshake for more than just negotiation of
cryptographic parameters. The TLS handshake validates protocol cryptographic parameters. The TLS handshake validates protocol
version selection, provides preliminary values for QUIC transport version selection, provides preliminary values for QUIC transport
parameters, and allows a server to perform return routeability checks parameters, and allows a server to perform return routeability checks
on clients. on clients.
9.1. Protocol and Version Negotiation 10.1. Protocol and Version Negotiation
The QUIC version negotiation mechanism is used to negotiate the The QUIC version negotiation mechanism is used to negotiate the
version of QUIC that is used prior to the completion of the version of QUIC that is used prior to the completion of the
handshake. However, this packet is not authenticated, enabling an handshake. However, this packet is not authenticated, enabling an
active attacker to force a version downgrade. active attacker to force a version downgrade.
To ensure that a QUIC version downgrade is not forced by an attacker, To ensure that a QUIC version downgrade is not forced by an attacker,
version information is copied into the TLS handshake, which provides version information is copied into the TLS handshake, which provides
integrity protection for the QUIC negotiation. This does not prevent integrity protection for the QUIC negotiation. This does not prevent
version downgrade during the handshake, though it means that such a version downgrade prior to the completion of the handshake, though it
downgrade causes a handshake failure. means that a downgrade causes a handshake failure.
TLS uses Application Layer Protocol Negotiation (ALPN) [RFC7301] to TLS uses Application Layer Protocol Negotiation (ALPN) [RFC7301] to
select an application protocol. The application-layer protocol MAY select an application protocol. The application-layer protocol MAY
restrict the QUIC versions that it can operate over. Servers MUST restrict the QUIC versions that it can operate over. Servers MUST
select an application protocol compatible with the QUIC version that select an application protocol compatible with the QUIC version that
the client has selected. the client has selected.
If the server cannot select a compatible combination of application If the server cannot select a compatible combination of application
protocol and QUIC version, it MUST abort the connection. A client protocol and QUIC version, it MUST abort the connection. A client
MUST abort a connection if the server picks an incompatible MUST abort a connection if the server picks an incompatible
combination of QUIC version and ALPN identifier. combination of QUIC version and ALPN identifier.
9.2. QUIC Transport Parameters Extension 10.2. QUIC Transport Parameters Extension
QUIC transport parameters are carried in a TLS extension. Different QUIC transport parameters are carried in a TLS extension. Different
versions of QUIC might define a different format for this struct. versions of QUIC might define a different format for this struct.
Including transport parameters in the TLS handshake provides Including transport parameters in the TLS handshake provides
integrity protection for these values. integrity protection for these values.
enum { enum {
quic_transport_parameters(26), (65535) quic_transport_parameters(26), (65535)
} ExtensionType; } ExtensionType;
The "extension_data" field of the quic_transport_parameters extension The "extension_data" field of the quic_transport_parameters extension
contains a value that is defined by the version of QUIC that is in contains a value that is defined by the version of QUIC that is in
use. The quic_transport_parameters extension carries a use. The quic_transport_parameters extension carries a
TransportParameters when the version of QUIC defined in TransportParameters when the version of QUIC defined in
[QUIC-TRANSPORT] is used. [QUIC-TRANSPORT] is used.
9.3. Priming 0-RTT The quic_transport_parameters extension is carried in the ClientHello
and the EncryptedExtensions messages during the handshake. The
extension MAY be included in a NewSessionTicket message.
10.3. Priming 0-RTT
QUIC uses TLS without modification. Therefore, it is possible to use QUIC uses TLS without modification. Therefore, it is possible to use
a pre-shared key that was obtained in a TLS connection over TCP to a pre-shared key that was established in a TLS handshake over TCP to
enable 0-RTT in QUIC. Similarly, QUIC can provide a pre-shared key enable 0-RTT in QUIC. Similarly, QUIC can provide a pre-shared key
that can be used to enable 0-RTT in TCP. that can be used to enable 0-RTT in TCP.
All the restrictions on the use of 0-RTT apply, with the exception of All the restrictions on the use of 0-RTT apply, with the exception of
the ALPN label, which MUST only change to a label that is explicitly the ALPN label, which MUST only change to a label that is explicitly
designated as being compatible. The client indicates which ALPN designated as being compatible. The client indicates which ALPN
label it has chosen by placing that ALPN label first in the ALPN label it has chosen by placing that ALPN label first in the ALPN
extension. extension.
The certificate that the server uses MUST be considered valid for The certificate that the server uses MUST be considered valid for
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Source address validation is not completely portable between Source address validation is not completely portable between
different protocol stacks. Even if the source IP address remains different protocol stacks. Even if the source IP address remains
constant, the port number is likely to be different. Packet constant, the port number is likely to be different. Packet
reflection attacks are still possible in this situation, though the reflection attacks are still possible in this situation, though the
set of hosts that can initiate these attacks is greatly reduced. A set of hosts that can initiate these attacks is greatly reduced. A
server might choose to avoid source address validation for such a server might choose to avoid source address validation for such a
connection, or allow an increase to the amount of data that it sends connection, or allow an increase to the amount of data that it sends
toward the client without source validation. toward the client without source validation.
10. Security Considerations 11. Security Considerations
There are likely to be some real clangers here eventually, but the There are likely to be some real clangers here eventually, but the
current set of issues is well captured in the relevant sections of current set of issues is well captured in the relevant sections of
the main text. the main text.
Never assume that because it isn't in the security considerations Never assume that because it isn't in the security considerations
section it doesn't affect security. Most of this document does. section it doesn't affect security. Most of this document does.
10.1. Packet Reflection Attack Mitigation 11.1. Packet Reflection Attack Mitigation
A small ClientHello that results in a large block of handshake A small ClientHello that results in a large block of handshake
messages from a server can be used in packet reflection attacks to messages from a server can be used in packet reflection attacks to
amplify the traffic generated by an attacker. amplify the traffic generated by an attacker.
Certificate caching [RFC7924] can reduce the size of the server's Certificate caching [RFC7924] can reduce the size of the server's
handshake messages significantly. handshake messages significantly.
QUIC requires that the packet containing a ClientHello be padded to QUIC requires that the packet containing a ClientHello be padded to a
the size of the maximum transmission unit (MTU). A server is less minimum size. A server is less likely to generate a packet
likely to generate a packet reflection attack if the data it sends is reflection attack if the data it sends is a small multiple of this
a small multiple of this size. A server SHOULD use a size. A server SHOULD use a HelloRetryRequest if the size of the
HelloRetryRequest if the size of the handshake messages it sends is handshake messages it sends is likely to significantly exceed the
likely to significantly exceed the size of the packet containing the size of the packet containing the ClientHello.
ClientHello.
10.2. Peer Denial of Service 11.2. Peer Denial of Service
QUIC, TLS and HTTP/2 all contain a messages that have legitimate uses QUIC, TLS and HTTP/2 all contain a messages that have legitimate uses
in some contexts, but that can be abused to cause a peer to expend in some contexts, but that can be abused to cause a peer to expend
processing resources without having any observable impact on the processing resources without having any observable impact on the
state of the connection. If processing is disproportionately large state of the connection. If processing is disproportionately large
in comparison to the observable effects on bandwidth or state, then in comparison to the observable effects on bandwidth or state, then
this could allow a malicious peer to exhaust processing capacity this could allow a malicious peer to exhaust processing capacity
without consequence. without consequence.
QUIC prohibits the sending of empty "STREAM" frames unless they are QUIC prohibits the sending of empty "STREAM" frames unless they are
skipping to change at page 33, line 9 skipping to change at page 33, line 48
generate unnecessary work. Once the TLS handshake is complete, generate unnecessary work. Once the TLS handshake is complete,
endpoints SHOULD NOT send TLS application data records unless it is endpoints SHOULD NOT send TLS application data records unless it is
to hide the length of QUIC records. QUIC packet protection does not to hide the length of QUIC records. QUIC packet protection does not
include any allowance for padding; padded TLS application data include any allowance for padding; padded TLS application data
records can be used to mask the length of QUIC frames. records can be used to mask the length of QUIC frames.
While there are legitimate uses for some redundant packets, While there are legitimate uses for some redundant packets,
implementations SHOULD track redundant packets and treat excessive implementations SHOULD track redundant packets and treat excessive
volumes of any non-productive packets as indicative of an attack. volumes of any non-productive packets as indicative of an attack.
11. Error codes 12. Error codes
The portion of the QUIC error code space allocated for the crypto The portion of the QUIC error code space allocated for the crypto
handshake is 0xC0000000-0xFFFFFFFF. The following error codes are handshake is 0xC0000000-0xFFFFFFFF. The following error codes are
defined when TLS is used for the crypto handshake: defined when TLS is used for the crypto handshake:
TLS_HANDSHAKE_FAILED (0xC000001C): The TLS handshake failed. TLS_HANDSHAKE_FAILED (0xC000001C): The TLS handshake failed.
TLS_FATAL_ALERT_GENERATED (0xC000001D): A TLS fatal alert was sent, TLS_FATAL_ALERT_GENERATED (0xC000001D): A TLS fatal alert was sent,
causing the TLS connection to end prematurely. causing the TLS connection to end prematurely.
TLS_FATAL_ALERT_RECEIVED (0xC000001E): A TLS fatal alert was TLS_FATAL_ALERT_RECEIVED (0xC000001E): A TLS fatal alert was
received, causing the TLS connection to end prematurely. received, causing the TLS connection to end prematurely.
12. IANA Considerations 13. IANA Considerations
This document has no IANA actions. Yet. This document does not create any new IANA registries, but it does
utilize the following registries:
13. References o QUIC Transport Parameter Registry - IANA is to register the three
values found in Section 12.
13.1. Normative References o TLS ExtensionsType Registry - IANA is to register the
quic_transport_parameters extension found in Section 10.2.
Assigning 26 to the extension would be greatly appreciated. The
Recommended column is to be marked Yes.
o TLS Exporter Label Registry - IANA is requested to register
"EXPORTER-QUIC 0-RTT Secret" from Section 5.2.1 as well as
"EXPORTER-QUIC client 1-RTT Secret" and "EXPORTER-QUIC server
1-RTT Secret" from Section 5.2.2. The DTLS column is to be marked
No. The Recommended column is to be marked Yes.
14. References
14.1. Normative References
[I-D.ietf-tls-tls13] [I-D.ietf-tls-tls13]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", draft-ietf-tls-tls13-19 (work in progress), Version 1.3", draft-ietf-tls-tls13-20 (work in progress),
March 2017. April 2017.
[QUIC-TRANSPORT] [QUIC-TRANSPORT]
Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport". Multiplexed and Secure Transport", draft-ietf-quic-
transport (work in progress), May 2017.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated [RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated
Encryption", RFC 5116, DOI 10.17487/RFC5116, January 2008, Encryption", RFC 5116, DOI 10.17487/RFC5116, January 2008,
<http://www.rfc-editor.org/info/rfc5116>. <http://www.rfc-editor.org/info/rfc5116>.
[RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand [RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand
Key Derivation Function (HKDF)", RFC 5869, Key Derivation Function (HKDF)", RFC 5869,
DOI 10.17487/RFC5869, May 2010, DOI 10.17487/RFC5869, May 2010,
<http://www.rfc-editor.org/info/rfc5869>. <http://www.rfc-editor.org/info/rfc5869>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<http://www.rfc-editor.org/info/rfc7230>.
[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan, [RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
"Transport Layer Security (TLS) Application-Layer Protocol "Transport Layer Security (TLS) Application-Layer Protocol
Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301, Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
July 2014, <http://www.rfc-editor.org/info/rfc7301>. July 2014, <http://www.rfc-editor.org/info/rfc7301>.
13.2. Informative References 14.2. Informative References
[AEBounds] [AEBounds]
Luykx, A. and K. Paterson, "Limits on Authenticated Luykx, A. and K. Paterson, "Limits on Authenticated
Encryption Use in TLS", March 2016, Encryption Use in TLS", March 2016,
<http://www.isg.rhul.ac.uk/~kp/TLS-AEbounds.pdf>. <http://www.isg.rhul.ac.uk/~kp/TLS-AEbounds.pdf>.
[FNV] Fowler, G., Noll, L., Vo, K., Eastlake, D., and T. Hansen,
"The FNV Non-Cryptographic Hash Algorithm", draft-
eastlake-fnv-12 (work in progress), December 2016.
[QUIC-HTTP] [QUIC-HTTP]
Bishop, M., Ed., "Hypertext Transfer Protocol (HTTP) over Bishop, M., Ed., "Hypertext Transfer Protocol (HTTP) over
QUIC". QUIC", draft-ietf-quic-http (work in progress), May 2017.
[QUIC-RECOVERY] [QUIC-RECOVERY]
Iyengar, J., Ed. and I. Swett, Ed., "QUIC Loss Detection Iyengar, J., Ed. and I. Swett, Ed., "QUIC Loss Detection
and Congestion Control". and Congestion Control", draft-ietf-quic-recovery (work in
progress), May 2017.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981,
<http://www.rfc-editor.org/info/rfc793>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000, DOI 10.17487/RFC2818, May 2000,
<http://www.rfc-editor.org/info/rfc2818>. <http://www.rfc-editor.org/info/rfc2818>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<http://www.rfc-editor.org/info/rfc5280>. <http://www.rfc-editor.org/info/rfc5280>.
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015,
<http://www.rfc-editor.org/info/rfc7540>.
[RFC7924] Santesson, S. and H. Tschofenig, "Transport Layer Security [RFC7924] Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", RFC 7924, (TLS) Cached Information Extension", RFC 7924,
DOI 10.17487/RFC7924, July 2016, DOI 10.17487/RFC7924, July 2016,
<http://www.rfc-editor.org/info/rfc7924>. <http://www.rfc-editor.org/info/rfc7924>.
Appendix A. Contributors Appendix A. Contributors
Ryan Hamilton was originally an author of this specification. Ryan Hamilton was originally an author of this specification.
Appendix B. Acknowledgments Appendix B. Acknowledgments
skipping to change at page 35, line 22 skipping to change at page 36, line 22
Christian Huitema, Jana Iyengar, Adam Langley, Roberto Peon, Eric Christian Huitema, Jana Iyengar, Adam Langley, Roberto Peon, Eric
Rescorla, Ian Swett, and many others. Rescorla, Ian Swett, and many others.
Appendix C. Change Log Appendix C. Change Log
*RFC Editor's Note:* Please remove this section prior to *RFC Editor's Note:* Please remove this section prior to
publication of a final version of this document. publication of a final version of this document.
Issue and pull request numbers are listed with a leading octothorp. Issue and pull request numbers are listed with a leading octothorp.
C.1. Since draft-ietf-quic-tls-01: C.1. Since draft-ietf-quic-tls-02
o Updates to match changes in transport draft
C.2. Since draft-ietf-quic-tls-01
o Use TLS alerts to signal TLS errors (#272, #374) o Use TLS alerts to signal TLS errors (#272, #374)
o Require ClientHello to fit in a single packet (#338) o Require ClientHello to fit in a single packet (#338)
o The second client handshake flight is now sent in the clear (#262, o The second client handshake flight is now sent in the clear (#262,
#337) #337)
o The QUIC header is included as AEAD Associated Data (#226, #243, o The QUIC header is included as AEAD Associated Data (#226, #243,
#302) #302)
skipping to change at page 35, line 47 skipping to change at page 37, line 5
o Require at least TLS 1.3 (#138) o Require at least TLS 1.3 (#138)
o Define transport parameters as a TLS extension (#122) o Define transport parameters as a TLS extension (#122)
o Define handling for protected packets before the handshake o Define handling for protected packets before the handshake
completes (#39) completes (#39)
o Decouple QUIC version and ALPN (#12) o Decouple QUIC version and ALPN (#12)
C.2. Since draft-ietf-quic-tls-00: C.3. Since draft-ietf-quic-tls-00
o Changed bit used to signal key phase. o Changed bit used to signal key phase
o Updated key phase markings during the handshake. o Updated key phase markings during the handshake
o Added TLS interface requirements section. o Added TLS interface requirements section
o Moved to use of TLS exporters for key derivation. o Moved to use of TLS exporters for key derivation
o Moved TLS error code definitions into this document. o Moved TLS error code definitions into this document
C.3. Since draft-thomson-quic-tls-01: C.4. Since draft-thomson-quic-tls-01
o Adopted as base for draft-ietf-quic-tls. o Adopted as base for draft-ietf-quic-tls
o Updated authors/editors list. o Updated authors/editors list
o Added status note. o Added status note
Authors' Addresses Authors' Addresses
Martin Thomson (editor) Martin Thomson (editor)
Mozilla Mozilla
Email: martin.thomson@gmail.com Email: martin.thomson@gmail.com
Sean Turner (editor) Sean Turner (editor)
sn3rd sn3rd
Email: sean@sn3rd.com
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