< draft-schinazi-masque-00.txt   draft-schinazi-masque-01.txt >
Network Working Group D. Schinazi Network Working Group D. Schinazi
Internet-Draft Google LLC Internet-Draft Google LLC
Intended status: Experimental February 28, 2019 Intended status: Experimental July 08, 2019
Expires: September 1, 2019 Expires: January 9, 2020
The MASQUE Protocol The MASQUE Protocol
draft-schinazi-masque-00 draft-schinazi-masque-01
Abstract Abstract
This document describes MASQUE (Multiplexed Application Substrate This document describes MASQUE (Multiplexed Application Substrate
over QUIC Encryption). MASQUE is a mechanism that allows co-locating over QUIC Encryption). MASQUE is a mechanism that allows co-locating
and obfuscating networking applications behind an HTTPS web server. and obfuscating networking applications behind an HTTPS web server.
The currently prevalent use-case is to allow running a VPN server The currently prevalent use-case is to allow running a proxy or VPN
that is indistinguishable from an HTTPS server to any unauthenticated server that is indistinguishable from an HTTPS server to any
observer. We do not expect major providers and CDNs to deploy this unauthenticated observer. We do not expect major providers and CDNs
behind their main TLS certificate, as they are not willing to take to deploy this behind their main TLS certificate, as they are not
the risk of getting blocked, as shown when domain fronting was willing to take the risk of getting blocked, as shown when domain
blocked. An expected use would be for individuals to enable this fronting was blocked. An expected use would be for individuals to
behind their personal websites via easy to configure open-source enable this behind their personal websites via easy to configure
software. open-source software.
This document is a straw-man proposal. It does not contain enough This document is a straw-man proposal. It does not contain enough
details to implement the protocol, and is currently intended to spark details to implement the protocol, and is currently intended to spark
discussions on the approach it is taking. As we have not yet found a discussions on the approach it is taking. Discussion of this work is
home for this work, discussion is encouraged to happen on the GitHub encouraged to happen on the MASQUE IETF mailing list masque@ietf.org
repository which contains the draft: [1] or on the GitHub repository which contains the draft:
https://github.com/DavidSchinazi/masque-drafts [1]. https://github.com/DavidSchinazi/masque-drafts [2].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 https://datatracker.ietf.org/drafts/current/. Drafts is at https://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 1, 2019. This Internet-Draft will expire on January 9, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 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
(https://trustee.ietf.org/license-info) in effect on the date of (https://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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions and Definitions . . . . . . . . . . . . . . . 3 1.1. Conventions and Definitions . . . . . . . . . . . . . . . 3
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Invisibility of VPN Usage . . . . . . . . . . . . . . . . 3 2.1. Protection from Network Providers . . . . . . . . . . . . 3
2.2. Invisibility of the Server . . . . . . . . . . . . . . . 3 2.2. Protection from Web Servers . . . . . . . . . . . . . . . 4
2.3. Fallback to HTTP/2 over TLS over TCP . . . . . . . . . . 4 2.3. Making a Home Server Available . . . . . . . . . . . . . 4
3. Overview of the Mechanism . . . . . . . . . . . . . . . . . . 4 2.4. Onion Routing . . . . . . . . . . . . . . . . . . . . . . 4
4. Mechanisms the Server Can Advertise to Authenticated Clients 5 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. HTTP Proxy . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Invisibility of Usage . . . . . . . . . . . . . . . . . . 4
4.2. DNS over HTTPS . . . . . . . . . . . . . . . . . . . . . 5 3.2. Invisibility of the Server . . . . . . . . . . . . . . . 5
4.3. UDP Proxying . . . . . . . . . . . . . . . . . . . . . . 5 3.3. Fallback to HTTP/2 over TLS over TCP . . . . . . . . . . 5
4.4. IP Proxying . . . . . . . . . . . . . . . . . . . . . . . 6 4. Overview of the Mechanism . . . . . . . . . . . . . . . . . . 5
4.5. Path MTU Discovery . . . . . . . . . . . . . . . . . . . 6 5. Mechanisms the Server Can Advertise to Authenticated Clients 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5.1. HTTP Proxy . . . . . . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 5.2. DNS over HTTPS . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.3. UDP Proxying . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 7 5.4. QUIC Proxying . . . . . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 8 5.5. IP Proxying . . . . . . . . . . . . . . . . . . . . . . . 7
7.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.6. Path MTU Discovery . . . . . . . . . . . . . . . . . . . 7
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.7. Service Registration . . . . . . . . . . . . . . . . . . 7
Design Justifications . . . . . . . . . . . . . . . . . . . . . . 9 6. Operation over HTTP/2 . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7.1. Traffic Analysis . . . . . . . . . . . . . . . . . . . . 8
7.2. Untrusted Servers . . . . . . . . . . . . . . . . . . . . 8
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
9.1. Normative References . . . . . . . . . . . . . . . . . . 9
9.2. Informative References . . . . . . . . . . . . . . . . . 10
9.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 11
Design Justifications . . . . . . . . . . . . . . . . . . . . . . 11
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
This document describes MASQUE (Multiplexed Application Substrate This document describes MASQUE (Multiplexed Application Substrate
over QUIC Encryption). MASQUE is a mechanism that allows co-locating over QUIC Encryption). MASQUE is a mechanism that allows co-locating
and obfuscating networking applications behind an HTTPS web server. and obfuscating networking applications behind an HTTPS web server.
The currently prevalent use-case is to allow running a VPN server The currently prevalent use-case is to allow running a proxy or VPN
that is indistinguishable from an HTTPS server to any unauthenticated server that is indistinguishable from an HTTPS server to any
observer. We do not expect major providers and CDNs to deploy this unauthenticated observer. We do not expect major providers and CDNs
behind their main TLS certificate, as they are not willing to take to deploy this behind their main TLS certificate, as they are not
the risk of getting blocked, as shown when domain fronting was willing to take the risk of getting blocked, as shown when domain
blocked. An expected use would be for individuals to enable this fronting was blocked. An expected use would be for individuals to
behind their personal websites via easy to configure open-source enable this behind their personal websites via easy to configure
software. open-source software.
This document is a straw-man proposal. It does not contain enough This document is a straw-man proposal. It does not contain enough
details to implement the protocol, and is currently intended to spark details to implement the protocol, and is currently intended to spark
discussions on the approach it is taking. As we have not yet found a discussions on the approach it is taking. Discussion of this work is
home for this work, discussion is encouraged to happen on the GitHub encouraged to happen on the MASQUE IETF mailing list masque@ietf.org
repository which contains the draft: [3] or on the GitHub repository which contains the draft:
https://github.com/DavidSchinazi/masque-drafts [2]. https://github.com/DavidSchinazi/masque-drafts [4].
MASQUE leverages the efficient head-of-line blocking prevention MASQUE leverages the efficient head-of-line blocking prevention
features of the QUIC transport protocol [I-D.ietf-quic-transport] features of the QUIC transport protocol [I-D.ietf-quic-transport]
when MASQUE is used in an HTTP/3 [I-D.ietf-quic-http] server. MASQUE when MASQUE is used in an HTTP/3 [I-D.ietf-quic-http] server. MASQUE
can also run in an HTTP/2 server [RFC7540] but at a performance cost. can also run in an HTTP/2 server [RFC7540] but at a performance cost.
1.1. Conventions and Definitions 1.1. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
2. Requirements 2. Usage Scenarios
There are currently multiple usage scenarios that can benefit from
MASQUE.
2.1. Protection from Network Providers
Some users may wish to obfuscate the destination of their network
traffic from their network provider. This prevents network providers
from using data harvested from this network traffic in ways the user
did not intend.
2.2. Protection from Web Servers
There are many clients who would rather not establish a direct
connection to web servers, for example to avoid location tracking.
The clients can do that by running their traffic through a MASQUE
server. The web server will only see the IP address of the MASQUE
server, not that of the client.
2.3. Making a Home Server Available
It is often difficult to connect to a home server. The IP address
might change over time. Firewalls in the home router or in the
network may block incoming connections. Using a MASQUE server as a
rendez-vous point helps resolve these issues.
2.4. Onion Routing
Routing traffic through a MASQUE server only provides partial
protection against tracking, because the MASQUE server knows the
address of the client. Onion routing as it exists today mitigates
this issue for TCP/TLS. A MASQUE server could allow onion routing
over QUIC.
In this scenario, the client establishes a connection to the MASQUE
server, then through that to another MASQUE server, etc. This
creates a tree of MASQUE servers rooted at the client. QUIC
connections are mapped to a specific branch of the tree. The first
MASQUE server knows the actual address of the client, but the other
MASQUE servers only know the address of the previous server. To
assure reasonable privacy, the path should include at least 3 MASQUE
servers.
3. Requirements
This section describes the goals and requirements chosen for the This section describes the goals and requirements chosen for the
MASQUE protocol. MASQUE protocol.
2.1. Invisibility of VPN Usage 3.1. Invisibility of Usage
An authenticated client using the VPN appears to observers as a An authenticated client using MASQUE features appears to observers as
regular HTTPS client. Observers only see that HTTP/3 or HTTP/2 is a regular HTTPS client. Observers only see that HTTP/3 or HTTP/2 is
being used over an encrypted channel. No part of the exchanges being used over an encrypted channel. No part of the exchanges
between client and server may stick out. Note that traffic analysis between client and server may stick out. Note that traffic analysis
is currently considered out of scope. is discussed in Section 7.1.
2.2. Invisibility of the Server 3.2. Invisibility of the Server
To anyone without private keys, the server is indistinguishable from To anyone without private keys, the server is indistinguishable from
a regular web server. It is impossible to send an unauthenticated a regular web server. It is impossible to send an unauthenticated
probe that the server would reply to differently than if it were a probe that the server would reply to differently than if it were a
normal web server. normal web server.
2.3. Fallback to HTTP/2 over TLS over TCP 3.3. Fallback to HTTP/2 over TLS over TCP
When QUIC is blocked, MASQUE can run over TCP and still satisfy When QUIC is blocked, MASQUE can run over TCP and still satisfy
previous requirements. Note that in this scenario performance may be previous requirements. Note that in this scenario performance may be
negatively impacted. negatively impacted.
3. Overview of the Mechanism 4. Overview of the Mechanism
The server runs an HTTPS server on port 443, and has a valid TLS The server runs an HTTPS server on port 443, and has a valid TLS
certificate for its domain. The client has a public/private key certificate for its domain. The client has a public/private key
pair, and the server maintains a list of authorized MASQUE clients, pair, and the server maintains a list of authorized MASQUE clients,
and their public key. (Alternatively, clients can also be and their public key. (Alternatively, clients can also be
authenticated using a shared secret.) The client starts by authenticated using a shared secret.) The client starts by
establishing a regular HTTPS connection to the server (HTTP/3 over establishing a regular HTTPS connection to the server (HTTP/3 over
QUIC or HTTP/2 over TLS 1.3 [RFC8446] over TCP), and validates the QUIC or HTTP/2 over TLS 1.3 [RFC8446] over TCP), and validates the
server's TLS certificate as it normally would for HTTPS. If server's TLS certificate as it normally would for HTTPS. If
validation fails, the connection is aborted. The client then uses a validation fails, the connection is aborted. At this point the
TLS keying material exporter [RFC5705] with label "EXPORTER-masque" client can send regular unauthenticated HTTP requests to the server.
and no context to generate a 32-byte key. This key is then used as a When it wishes to start MASQUE, the client uses HTTP Transport
nonce to prevent replay attacks. The client then sends an HTTP Authentication (draft-schinazi-httpbis-transport-auth) to prove its
CONNECT request for "/.well-known/masque/initial" with the :protocol possession of its associated key. The client sends the Transport-
pseudo-header field set to "masque", and a "Masque-Authentication:" Authentication header alongside an HTTP CONNECT request for "/.well-
header. The MASQUE authentication header differs from the HTTP known/masque/initial" with the :protocol pseudo-header field set to
"Authorization" header in that it applies to the underlying "masque".
connection instead of being per-request. It can use either a shared
secret or asymmetric authentication. The asymmetric variant uses
authentication method "PublicKey", and it transmits a signature of
the nonce with the client's public key encoded in base64 format,
followed by other information such as the client username and
signature algorithm OID. The symmetric variant uses authentication
method "HMAC" and transmits an HMAC of the nonce with the shared
secret instead of a signature. For example this header could look
like:
Masque-Authentication: PublicKey u="am9obi5kb2U=";a=1.3.101.112;
s="SW5zZXJ0IHNpZ25hdHVyZSBvZiBub25jZSBoZXJlIHdo
aWNoIHRha2VzIDUxMiBiaXRzIGZvciBFZDI1NTE5IQ=="
Masque-Authentication: HMAC u="am9obi5kb2U=";a=2.16.840.1.101.3.4.2.3;
s="SW5zZXJ0IHNpZ25hdHVyZSBvZiBub25jZSBoZXJlIHdo
aWNoIHRha2VzIDUxMiBiaXRzIGZvciBFZDI1NTE5IQ=="
Figure 1: MASQUE Authentication Format Example When the server receives this CONNECT request, it authenticates the
client and if that fails responds with code "405 Method Not Allowed",
making sure its response is the same as what it would return for any
unexpected CONNECT request. If authentication succeeds, the server
responds with code "101 Switching Protocols", and from then on this
HTTP stream is now dedicated to the MASQUE protocol. That protocol
provides a reliable bidirectional message exchange mechanism, which
is used by the client and server to negotiate what protocol options
are supported and enabled by policy, and client VPN configuration
such as IP addresses. When using QUIC, this protocol also allows
endpoints to negotiate the use of QUIC extensions, such as support
for the DATAGRAM extension [I-D.pauly-quic-datagram].
When the server receives this CONNECT request, it verifies the Clients MUST NOT attempt to "resume" MASQUE state similarly to how
signature and if that fails responds with code "405 Method Not TLS sessions can be resumed. Every new QUIC or TLS connection
Allowed", making sure its response is the same as what it would requires fully authenticating the client and server. QUIC 0-RTT and
return for any unexpected CONNECT request. If the signature TLS early data MUST NOT be used with MASQUE as they are not forward
verifies, the server responds with code "101 Switching Protocols", secure.
and from then on this HTTP stream is now dedicated to the MASQUE
protocol. That protocol provides a reliable bidirectional message
exchange mechanism, which is used by the client and server to
negotiate what protocol options are supported and enabled by policy,
and client VPN configuration such as IP addresses. When using QUIC,
this protocol also allows endpoints to negotiate the use of QUIC
extensions, such as support for the DATAGRAM extension
[I-D.pauly-quic-datagram].
4. Mechanisms the Server Can Advertise to Authenticated Clients 5. Mechanisms the Server Can Advertise to Authenticated Clients
Once a server has authenticated the client's MASQUE CONNECT request, Once a server has authenticated the client's MASQUE CONNECT request,
it advertises services that the client may use. These services allow it advertises services that the client may use.
for example varying degrees of proxying services to help a client
obfuscate the ultimate destination of their traffic.
4.1. HTTP Proxy 5.1. HTTP Proxy
The client can make proxied HTTP requests through the server to other The client can make proxied HTTP requests through the server to other
servers. In practice this will mean using the CONNECT method to servers. In practice this will mean using the CONNECT method to
establish a stream over which to run TLS to a different remote establish a stream over which to run TLS to a different remote
destination. destination. The proxy applies back-pressure to streams in both
directions.
4.2. DNS over HTTPS 5.2. DNS over HTTPS
The client can send DNS queries using DNS over HTTPS (DoH) [RFC8484] The client can send DNS queries using DNS over HTTPS (DoH) [RFC8484]
to the MASQUE server. to the MASQUE server.
4.3. UDP Proxying 5.3. UDP Proxying
In order to support WebRTC or QUIC to further servers, clients need a In order to support WebRTC or QUIC to further servers, clients need a
way to relay UDP onwards to a remote server. In practice for most way to relay UDP onwards to a remote server. In practice for most
widely deployed protocols other than DNS, this involves many widely deployed protocols other than DNS, this involves many
datagrams over the same ports. Therefore this mechanism implements datagrams over the same ports. Therefore this mechanism implements
that efficiently: clients can use the MASQUE protocol stream to that efficiently: clients can use the MASQUE protocol stream to
request an UDP association to an IP address and UDP port pair. In request an UDP association to an IP address and UDP port pair. In
QUIC, the server would reply with a DATAGRAM_ID that the client can QUIC, the server would reply with a DATAGRAM_ID that the client can
then use to have UDP datagrams sent to this remote server. Datagrams then use to have UDP datagrams sent to this remote server. Datagrams
are then simply transferred between the DATAGRAMs with this ID and are then simply transferred between the DATAGRAMs with this ID and
the outer server. There will also be a message on the MASQUE the outer server. There will also be a message on the MASQUE
protocol stream to request shutdown of a UDP association to save protocol stream to request shutdown of a UDP association to save
resources when it is no longer needed. When running over TCP, the resources when it is no longer needed. When running over TCP, the
client opens a new stream with a CONNECT request to the "masque-udp- client opens a new stream with a CONNECT request to the "masque-udp-
proxy" protocol and then sends datagrams encapsulated inside the proxy" protocol and then sends datagrams encapsulated inside the
stream with a two-byte length prefix in network byte order. The stream with a two-byte length prefix in network byte order. The
target IP and port are sent as part of the URL query. Resetting that target IP and port are sent as part of the URL query. Resetting that
stream instructs the server to release any associates resources. stream instructs the server to release any associates resources.
4.4. IP Proxying 5.4. QUIC Proxying
By leveraging QUIC client connection IDs, a MASQUE server can act as
a QUIC proxy while only using one UDP port. The server informs the
client of a scheme for client connection IDs (for example, random of
a minimum length or vended by the MASQUE server) and then the server
can forward those packets to further web servers.
This mechanism can elide the connection IDs on the link between the
client and MASQUE server by negotiating a mapping between
DATAGRAM_IDs and the tuple (client connection ID, server connection
ID, server IP address, server port).
Compared to UDP proxying, this mode has the advantage of only
requiring one UDP port to be open on the MASQUE server, and can lower
the overhead on the link between client and MASQUE server by
compressing connection IDs.
5.5. IP Proxying
For the rare cases where the previous mechanisms are not sufficient, For the rare cases where the previous mechanisms are not sufficient,
proxying can be performed at the IP layer. This would use a proxying can be performed at the IP layer. This would use a
different DATAGRAM_ID and IP datagrams would be encoded inside it different DATAGRAM_ID and IP datagrams would be encoded inside it
without framing. Over TCP, a dedicated stream with two byte length without framing. Over TCP, a dedicated stream with two byte length
prefix would be used. The server can inspect the IP datagram to look prefix would be used. The server can inspect the IP datagram to look
for the destination address in the IP header. for the destination address in the IP header.
4.5. Path MTU Discovery 5.6. Path MTU Discovery
In the main deployment of this mechanism, QUIC will be used between In the main deployment of this mechanism, QUIC will be used between
client and server, and that will most likely be the smallest MTU link client and server, and that will most likely be the smallest MTU link
in the path due to QUIC header and authentication tag overhead. The in the path due to QUIC header and authentication tag overhead. The
client is responsible for not sending overly large UDP packets and client is responsible for not sending overly large UDP packets and
notifying the server of the low MTU. Therefore PMTUD is currently notifying the server of the low MTU. Therefore PMTUD is currently
seen as out of scope of this document. seen as out of scope of this document.
5. Security Considerations 5.7. Service Registration
MASQUE can be used to make a home server accessible on the wide area.
The home server authenticates to the MASQUE server and registers a
domain name it wishes to serve. The MASQUE server can then forward
any traffic it receives for that domain name (by inspecting the TLS
Server Name Indication (SNI) extension) to the home server. This
received traffic is not authenticated and it allows non-modified
clients to communicate with the home server without knowing it is not
colocated with the MASQUE server.
To help obfuscate the home server, deployments can use Encrypted
Server Name Indication (ESNI) [I-D.ietf-tls-esni]. That will require
the MASQUE server sending the cleartext SNI to the home server.
6. Operation over HTTP/2
MASQUE implementations using HTTP/3 MUST support the fallback to
HTTP/2 to avoid incentivizing censors to block HTTP/3 or QUIC. When
running over HTTP/2, MASQUE uses the Extended CONNECT method to
negotiate the use of datagrams over an HTTP/2 stream
[I-D.kinnear-httpbis-http2-transport].
MASQUE implementations SHOULD discover that HTTP/3 is available (as
opposed to only HTTP/2) using the same mechanism as regular HTTP
traffic. This current standardized mechanism for this is HTTP
Alternative Services [RFC7838], but future mechanisms such as
[I-D.schwartz-httpbis-dns-alt-svc] can be used if they become
widespread.
7. Security Considerations
Here be dragons. TODO: slay the dragons. Here be dragons. TODO: slay the dragons.
6. IANA Considerations 7.1. Traffic Analysis
We will need to register: While MASQUE ensures that proxied traffic appears similar to regular
HTTP traffic, it doesn't inherently defeat traffic analysis.
However, the fact that MASQUE leverages QUIC allows it to segment
STREAM frames over multiple packets and add PADDING frames to change
the observable characteristics of its encrypted traffic. The exact
details of how to change traffic patterns to defeat traffic analysis
is considered an open research question and is out of scope for this
document.
o the TLS keying material exporter label "EXPORTER-masque" (spec When multiple MASQUE servers are available, a client can leverage
required) QUIC connection migration to seamlessly transition its end-to-end
QUIC connections by treating separate MASQUE servers as different
paths. This could afford an additional level of obfuscation in hopes
of rendering traffic analysis less effective.
https://www.iana.org/assignments/tls-parameters/tls- 7.2. Untrusted Servers
parameters.xhtml#exporter-labels [3]
o the new HTTP header "Masque-Authentication" As with any proxy or VPN technology, MASQUE hides some of the
client's private information (such as who they are communicating
with) from their network provider by transferring that information to
the MASQUE server. It is paramount that clients only use MASQUE
servers that they trust, as a malicious actor could easily setup a
MASQUE server and advertise it as a privacy solution in hopes of
attracting users to send it their traffic.
https://www.iana.org/assignments/message-headers/message- 8. IANA Considerations
headers.xhtml [4]
o the "/.well-known/masque/" URI (expert review) We will need to register:
o the "/.well-known/masque/" URI (expert review)
https://www.iana.org/assignments/well-known-uris/well-known- https://www.iana.org/assignments/well-known-uris/well-known-
uris.xhtml [5] uris.xhtml [5]
o The "masque" and "masque-udp-proxy" extended HTTP CONNECT o The "masque" and "masque-udp-proxy" extended HTTP CONNECT
protocols protocols
We will also need to define the MASQUE control protocol and that will We will also need to define the MASQUE control protocol and that will
be likely to define new registries of its own. be likely to define new registries of its own.
7. References 9. References
7.1. Normative References 9.1. Normative References
[I-D.ietf-quic-http] [I-D.ietf-quic-http]
Bishop, M., "Hypertext Transfer Protocol Version 3 Bishop, M., "Hypertext Transfer Protocol Version 3
(HTTP/3)", draft-ietf-quic-http-18 (work in progress), (HTTP/3)", draft-ietf-quic-http-20 (work in progress),
January 2019. April 2019.
[I-D.ietf-quic-transport] [I-D.ietf-quic-transport]
Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
and Secure Transport", draft-ietf-quic-transport-18 (work and Secure Transport", draft-ietf-quic-transport-20 (work
in progress), January 2019. in progress), April 2019.
[I-D.kinnear-httpbis-http2-transport]
Kinnear, E. and T. Pauly, "Using HTTP/2 as a Transport for
Arbitrary Bytestreams", draft-kinnear-httpbis-
http2-transport-01 (work in progress), March 2019.
[I-D.pauly-quic-datagram] [I-D.pauly-quic-datagram]
Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
Datagram Extension to QUIC", draft-pauly-quic-datagram-02 Datagram Extension to QUIC", draft-pauly-quic-datagram-03
(work in progress), February 2019. (work in progress), July 2019.
[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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5705] Rescorla, E., "Keying Material Exporters for Transport
Layer Security (TLS)", RFC 5705, DOI 10.17487/RFC5705,
March 2010, <https://www.rfc-editor.org/info/rfc5705>.
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext [RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540, Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015, DOI 10.17487/RFC7540, May 2015,
<https://www.rfc-editor.org/info/rfc7540>. <https://www.rfc-editor.org/info/rfc7540>.
[RFC7838] Nottingham, M., McManus, P., and J. Reschke, "HTTP
Alternative Services", RFC 7838, DOI 10.17487/RFC7838,
April 2016, <https://www.rfc-editor.org/info/rfc7838>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>. <https://www.rfc-editor.org/info/rfc8446>.
[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS [RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018, (DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/info/rfc8484>. <https://www.rfc-editor.org/info/rfc8484>.
7.2. Informative References 9.2. Informative References
[I-D.ietf-httpbis-http2-secondary-certs] [I-D.ietf-httpbis-http2-secondary-certs]
Bishop, M., Sullivan, N., and M. Thomson, "Secondary Bishop, M., Sullivan, N., and M. Thomson, "Secondary
Certificate Authentication in HTTP/2", draft-ietf-httpbis- Certificate Authentication in HTTP/2", draft-ietf-httpbis-
http2-secondary-certs-03 (work in progress), October 2018. http2-secondary-certs-04 (work in progress), April 2019.
[I-D.ietf-tls-esni]
Rescorla, E., Oku, K., Sullivan, N., and C. Wood,
"Encrypted Server Name Indication for TLS 1.3", draft-
ietf-tls-esni-03 (work in progress), March 2019.
[I-D.pardue-httpbis-http-network-tunnelling] [I-D.pardue-httpbis-http-network-tunnelling]
Pardue, L., "HTTP-initiated Network Tunnelling (HiNT)", Pardue, L., "HTTP-initiated Network Tunnelling (HiNT)",
draft-pardue-httpbis-http-network-tunnelling-01 (work in draft-pardue-httpbis-http-network-tunnelling-01 (work in
progress), October 2018. progress), October 2018.
[I-D.schwartz-httpbis-dns-alt-svc]
Schwartz, B. and M. Bishop, "Finding HTTP Alternative
Services via the Domain Name Service", draft-schwartz-
httpbis-dns-alt-svc-02 (work in progress), April 2018.
[I-D.schwartz-httpbis-helium] [I-D.schwartz-httpbis-helium]
Schwartz, B., "Hybrid Encapsulation Layer for IP and UDP Schwartz, B., "Hybrid Encapsulation Layer for IP and UDP
Messages (HELIUM)", draft-schwartz-httpbis-helium-00 (work Messages (HELIUM)", draft-schwartz-httpbis-helium-00 (work
in progress), June 2018. in progress), June 2018.
[I-D.sullivan-tls-post-handshake-auth] [I-D.sullivan-tls-post-handshake-auth]
Sullivan, N., Thomson, M., and M. Bishop, "Post-Handshake Sullivan, N., Thomson, M., and M. Bishop, "Post-Handshake
Authentication in TLS", draft-sullivan-tls-post-handshake- Authentication in TLS", draft-sullivan-tls-post-handshake-
auth-00 (work in progress), August 2016. auth-00 (work in progress), August 2016.
[RFC7427] Kivinen, T. and J. Snyder, "Signature Authentication in
the Internet Key Exchange Version 2 (IKEv2)", RFC 7427,
DOI 10.17487/RFC7427, January 2015,
<https://www.rfc-editor.org/info/rfc7427>.
[RFC8441] McManus, P., "Bootstrapping WebSockets with HTTP/2", [RFC8441] McManus, P., "Bootstrapping WebSockets with HTTP/2",
RFC 8441, DOI 10.17487/RFC8441, September 2018, RFC 8441, DOI 10.17487/RFC8441, September 2018,
<https://www.rfc-editor.org/info/rfc8441>. <https://www.rfc-editor.org/info/rfc8441>.
[RFC8471] Popov, A., Ed., Nystroem, M., Balfanz, D., and J. Hodges, [RFC8471] Popov, A., Ed., Nystroem, M., Balfanz, D., and J. Hodges,
"The Token Binding Protocol Version 1.0", RFC 8471, "The Token Binding Protocol Version 1.0", RFC 8471,
DOI 10.17487/RFC8471, October 2018, DOI 10.17487/RFC8471, October 2018,
<https://www.rfc-editor.org/info/rfc8471>. <https://www.rfc-editor.org/info/rfc8471>.
7.3. URIs 9.3. URIs
[1] https://github.com/DavidSchinazi/masque-drafts [1] mailto:masque@ietf.org
[2] https://github.com/DavidSchinazi/masque-drafts [2] https://github.com/DavidSchinazi/masque-drafts
[3] https://www.iana.org/assignments/tls-parameters/tls- [3] mailto:masque@ietf.org
parameters.xhtml#exporter-labels
[4] https://www.iana.org/assignments/message-headers/message- [4] https://github.com/DavidSchinazi/masque-drafts
headers.xhtml
[5] https://www.iana.org/assignments/well-known-uris/well-known- [5] https://www.iana.org/assignments/well-known-uris/well-known-
uris.xhtml uris.xhtml
Acknowledgments Acknowledgments
This proposal was inspired directly or indirectly by prior work from This proposal was inspired directly or indirectly by prior work from
many people. In particular, this work is related to many people. In particular, this work is related to
[I-D.schwartz-httpbis-helium] and [I-D.schwartz-httpbis-helium] and
[I-D.pardue-httpbis-http-network-tunnelling]. The mechanism used to [I-D.pardue-httpbis-http-network-tunnelling]. The mechanism used to
run the MASQUE protocol over HTTP/2 streams was inspired by run the MASQUE protocol over HTTP/2 streams was inspired by
[RFC8441]. Using the OID for the signature algorithm was inspired by [RFC8441]. Brendan Moran is to thank for the idea of leveraging
Signature Authentication in IKEv2 [RFC7427]. connection migration across MASQUE servers.
The author would like to thank Christophe A., an inspiration and true The author would like to thank Christophe A., an inspiration and true
leader of VPNs. leader of VPNs.
Design Justifications Design Justifications
Using an exported key as a nonce allows us to prevent replay attacks Using an exported key as a nonce allows us to prevent replay attacks
(since it depends on randomness from both endpoints of the TLS (since it depends on randomness from both endpoints of the TLS
connection) without requiring the server to send an explicit nonce connection) without requiring the server to send an explicit nonce
before it has authenticated the client. Adding an explicit nonce before it has authenticated the client. Adding an explicit nonce
 End of changes. 52 change blocks. 
144 lines changed or deleted 254 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/