Internet DRAFT - draft-jiang7369-webrtc-uri-scheme
draft-jiang7369-webrtc-uri-scheme
Network Working Group Jiang,Jianxing
Internet-Draft 19 April 2023
Intended status: Standards Track
Expires: 21 October 2023
The WebRTC URI Scheme
draft-jiang7369-webrtc-uri-scheme-02
Abstract
This document registers the "wr://" and "wrs://" URI schemes to aid
in the connect of WebRTC.
Note to Readers
_RFC EDITOR: please remove this section before publication_
The issues list for this draft can be found at
https://github.com/jiang7369/I-D/issues/
(https://github.com/jiang7369/I-D/issues/).
The most recent (unpublished) draft and demos is at
https://jiang7369.github.io/I-D/ (https://jiang7369.github.io/I-D/).
Recent changes are listed at https://github.com/jiang7369/I-
D/commits/gh-pages/ (https://github.com/jiang7369/I-D/commits/gh-
pages/).
See also the draft's current status in the IETF datatracker, at
https://datatracker.ietf.org/doc/draft-jiang7369-webrtc-uri-scheme/
(https://datatracker.ietf.org/doc/draft-jiang7369-webrtc-uri-
scheme/).
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 21 October 2023.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3
2. WebRTC URIs . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
3.1. Registration of New URI Schemes . . . . . . . . . . . . . 5
3.1.1. Registration of "wr" Scheme . . . . . . . . . . . . . 5
3.1.2. Registration of "wrs" Scheme . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Normative References . . . . . . . . . . . . . . . . . . 6
5.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. Example URIs . . . . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 9
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
URI is short and compact, convenient for transmission. You can even
send it offline to others without using any server, for example, you
can generate a QR Code for use.
WebRTC is a widely used real-time connection protocol, but unlike
WebSocket, it has no URI scheme.
This document registers the "wr://" and "wrs://" URI schemes to
supplement such gaps. When use the URI quickly open the connection,
you can immediately to realize communication between two clients.
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Use this URI Scheme to easily open a connection. You can open a data
channel, then the connection can be used as a file transfer or
signalling server, etc. You can also directly open a stable and
complex connection by passing more parameters.
WebRTC URI Scheme defines one endpoint of the connection, rather than
one port of the device. It defines the connection mode of WebRTC in
the Internet/LAN that conforms to human intuition. One device can
open multiple connections, corresponding to multiple endpoints,
without paying special attention to which port is currently used for
connection.
WebRTC URI Scheme may look like a compressed version of the SDP file.
It avoids the trouble of inconvenient transmission of SDP newline
characters, and does not expose more information in the first
connection.
In addition, the WebRTC URI Scheme facilitates communication between
two computers through browser application under the premise of light
server or no server. Changing connections on the network connect
pairs of endpoints. WebRTC endpoints are characterized by great
variability and fast variability. We can dynamically connect these
points to form a dynamic network.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
This document uses ABNF [RFC5234], Base64 [RFC4648]. It also uses
the pchar rule from [RFC3986].
2. WebRTC URIs
This specification defines two URI schemes, using the ABNF syntax
defined in RFC 5234 [RFC5234], and terminology and ABNF productions
defined by the URI specification RFC 3986 [RFC3986].
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wr-URI = "wr" ":" [ host-part ] "/" endpoint [ "?" query ]
wrs-URI = "wrs" ":" [ host-part ] "/" endpoint [ "?" query ]
host-part = "//" [ hostport ]
hostport = host [ ":" port ]
host = <host, defined in [RFC3986], Section 3.2.2>
port = <port, defined in [RFC3986], Section 3.2.3>
endpoint = basehash pwd ufrag
query = <query, defined in [RFC3986], Section 3.4>
basehash = 44<pchar>
pwd = *255<pchar>
ufrag = *255<pchar>
See [RFC3986], Section 3.3 for a definition of pchar. Disallowed
characters -- including non-ASCII characters -- MUST be encoded into
UTF-8 [RFC3629] and then percent-encoded ([RFC3986], Section 2.1).
The hostport component is OPTIONAL; By default, WebRTC connection
without STUN or TURN.
The port component is OPTIONAL; By default, "wr" runs on the same
ports as STUN and TURN: 3478 for "wr" over UDP and TCP, and 5349 for
"wrs" over TLS.
The ufrag component, pwd component and fingerprint used in basehash
component below can be find in attributes ([RFC8859], Section 5.12)
of SDP ([RFC8864], Section 5.12).
The basehash component MUST be calculated by the following steps:
1. get the length of pwd component
2. convert length of pwd component to hexadecimal (1 Byte)
3. get the fingerprint hexadecimal (32 Byte)
4. connect the length hexadecimal after the fingerprint hexadecimal
5. Calculate the Base64([RFC3986], Section 2.1) of the result
(33 Byte)
The advantage of this is to take endpoint component as a whole while
taking readability into consideration.
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Fragment identifiers are meaningless in the context of WebRTC URIs
and MUST NOT be used on these URIs. As with any URI scheme, the
character "#", when not indicating the start of a fragment, MUST be
escaped as %23.
Example URIs are listed in Appendix A.
3. IANA Considerations
3.1. Registration of New URI Schemes
3.1.1. Registration of "wr" Scheme
A |wr| URI identifies a WebRTC offer and answer name.
Scheme name:
wr
Status:
Permanent
Applications/protocols that use this scheme:
none yet
Security considerations:
See "Security Considerations" section.
Contact:
IETF <iesg@ietf.org>
Change controller:
IETF <iesg@ietf.org>
References:
(this document)
3.1.2. Registration of "wrs" Scheme
A |wrs| URI identifies a WebRTC offer and answer name and indicates
that traffic over that connection is to be protected via TLS
(including standard benefits of TLS such as data confidentiality and
integrity and endpoint authentication).
Scheme name:
wrs
Status:
Permanent
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Applications/protocols that use this scheme:
none yet
Security considerations:
See "Security Considerations" section.
Contact:
IETF <iesg@ietf.org>
Change controller:
IETF <iesg@ietf.org>
References:
(this document)
4. Security Considerations
The token ABNF rule allows tokens as small as 0 character. This is
not recommended practice; applications should evaluate their
requirements for entropy and issue tokens correspondingly. See
[RFC8445] for more information.
This document not solve the problem that attackers can flood stun/
turn servers. Too many open ports may cause network layer rejection.
Although the WebRTC URI Scheme makes connections easy to open, you
may connect untrusted nodes in static pages, just like click the link
of a phishing website. Before connecting, you must confirm whether
the URI provider is trusted.
If the stun/turn server is not trusted, man-in-the-middle attack may
occur on the "ws://" connection. "wrs://" is intended to reduce the
incidence of man-in-the-middle attack; it cannot prevent man-in-the-
middle attack on client to client connections.
And The server side of "wrs://" protocol SHALL ensure the security of
each link and the handling of blacklist.
5. References
5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
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[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/rfc/rfc3629>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/rfc/rfc3986>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/rfc/rfc4648>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/rfc/rfc5234>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8859] Nandakumar, S., "A Framework for Session Description
Protocol (SDP) Attributes When Multiplexing", RFC 8859,
DOI 10.17487/RFC8859, January 2021,
<https://www.rfc-editor.org/rfc/rfc8859>.
[RFC8864] Drage, K., Makaraju, M., Ejzak, R., Marcon, J., and R.
Even, Ed., "Negotiation Data Channels Using the Session
Description Protocol (SDP)", RFC 8864,
DOI 10.17487/RFC8864, January 2021,
<https://www.rfc-editor.org/rfc/rfc8864>.
5.2. Informative References
[RFC8445] Keranen, A., Holmberg, C., and J. Rosenberg, "Interactive
Connectivity Establishment (ICE): A Protocol for Network
Address Translator (NAT) Traversal", RFC 8445,
DOI 10.17487/RFC8445, July 2018,
<https://www.rfc-editor.org/rfc/rfc8445>.
[RFC8959] Nottingham, M., "The "secret-token" URI Scheme", RFC 8959,
DOI 10.17487/RFC8959, January 2021,
<https://www.rfc-editor.org/rfc/rfc8959>.
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Appendix A. Example URIs
The content of sdp is as follows:
a=ice-ufrag:Yb1d
a=ice-pwd:uCiLWVRLVIKkrl14SzyO4TMF
a=fingerprint:sha-256 B6:9E:F3:DD:8B:83:8D:F6:95:4E:76:40:AF:F2:78
:0B:CA:78:DA:0B:73:21:1E:28:93:4F:70:DA:47:B4:41:7E
The ufrag component is "Yb1d".
The pwd component is "uCiLWVRLVIKkrl14SzyO4TMF"
The basehash component before Base64 is
0xB69EF3DD8B838DF6954E7640AFF2780BCA78DA0B73211E28934F70DA47B4417E18,
The basehash component is
"tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w2ke0QX4Y"
So, the endpoint component is
"tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w2ke0QX4YuCiLWVRLVIKk
rl14SzyO4TMFYb1d"
Without STUN or TURN:
o If no STUN or TURN, expressed in "wr:///". For example:
* "wr:///tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w2ke0QX4YuCiLWVRLVI
Kkrl14SzyO4TMFYb1d?query=required&for&connect"
o Or omit "//", expressed in "wr:/". For example:
* "wr:/tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w2ke0QX4YuCiLWVRLVIKk
rl14SzyO4TMFYb1d?query"
With STUN or TURN:
o Use STUN or TURN server, For example:
* "wr://host.example.com/tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w2
ke0QX4YuCiLWVRLVIKkrl14SzyO4TMFYb1d?query"
o Use STUNs or TURNs server, For example:
* "wrs://host.example.com/tp7z3YuDjfaVTnZAr/J4C8p42gtzIR4ok09w
2ke0QX4YuCiLWVRLVIKkrl14SzyO4TMFYb1d?query"
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Acknowledgements
Frankly speaking, the document format refers to [RFC8959] when
writing.
Thank you~
Author's Address
Jiang,Jianxing
China
Email: jiang.7369@163.com
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