XEP-0076: Malicious Stanzas

This document defines an XMPP protocol extension for flagging malicious stanzas within Jabber/XMPP.

NOTICE: This document is Humorous. It MAY provide amusement but SHOULD NOT be taken seriously.

Document Information

Author Information

Peter Saint-Andre

JabberID: stpeter@jabber.org
URI: https://stpeter.im/

Joe Hildebrand

Email: jhildebrand@jabber.com
JabberID: hildjj@jabber.org

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1. Introduction
2. Requirements and Approach
3. Use Cases
    3.1. Evil Messages
    3.2. Evil Presence
    3.3. Evil IQs
4. Security Considerations
5. IANA Considerations
6. XMPP Registrar Considerations
Notes
Revision History

1. Introduction

RFC 3514 [1], published just today (2003-04-01), defines a mechanism for specifying the "evil bit" in IPv4 in order to determine if a packet was sent with malicious intent. In Section 5 ("Related Work") of that RFC, reference is made to complementary mechanisms for other forms of evil such as IPv6 support and the application/evil MIME type. Because the XMPP Standards Foundation (XSF) [2] desires to maintain compliance with protocols developed by core Internet standards bodies, the current document defines a complementary mechanism for Jabber support of evil.

2. Requirements and Approach

Any one of the foregoing data elements can be used with malicious intent. Therefore a generalized mechanism is needed. Because XML namespaces are used within Jabber to properly scope data, this document proposes a new namespace ('http://jabber.org/protocol/evil') to implement the desired functionality.

3. Use Cases

3.1 Evil Messages

If a Jabber entity sends an evil message, it MUST include an appropriately namespaced extension in the message stanza:

Example 1. Jabber Entity Sends Evil Message

<message 
    from='iago@shakespeare.lit/pda'
    to='emilia@shakespeare.lit/cell'>
  <body>
      I told him what I thought, and told no more
      Than what he found himself was apt and true.
  </body>
  <evil xmlns='http://jabber.org/protocol/evil'/>
</message>

3.2 Evil Presence

If a Jabber entity sends evil presence information, it MUST include an appropriately namespaced extension in the presence stanza:

Example 2. Jabber Entity Sends Evil Presence

<presence from='iago@shakespeare.lit/pda'>
  <show>dnd</show>
  <status>Fomenting dissension</status>
  <evil xmlns='http://jabber.org/protocol/evil'/>
</presence>

3.3 Evil IQs

If a Jabber entity provides evil information in an IQ exchange, it MUST include an appropriately namespaced extension in the IQ stanza:

Example 3. Jabber Entity Sends Evil Message

<iq 
    from='iago@shakespeare.lit/pda'
    to='emilia@shakespeare.lit/cell'
    id='evil1'>
  <query xmlns='jabber:iq:version'>
    <name>Stabber</name>
    <version>666</version>
    <os>FiendOS</os>
  </query>
  <evil xmlns='http://jabber.org/protocol/evil'/>
</iq>

4. Security Considerations

Because the 'http://jabber.org/protocol/evil' namespace flags an XML stanza as malicious, it is critically important that an entity appropriately process an XML stanza that contains the evil extension. Mission-critical applications SHOULD ignore any stanzas tagged with the evil extension. Evil servers MAY pass through evil stanzas unmodified. Really evil servers MAY silently delete the evil extension. Jabber entities that are evil to the core SHOULD support channel-level evil as defined in RFC 3514, since this document defines per-stanza evil only.

5. IANA Considerations

6. XMPP Registrar Considerations

The XMPP Registrar [4] shall register the 'http://jabber.org/protocol/evil' namespace as a result of this document.

Notes

1. RFC 3514: The Security Flag in the IPv4 Header <http://tools.ietf.org/html/rfc3514>.

2. The XMPP Standards Foundation (XSF) is an independent, non-profit membership organization that develops open extensions to the IETF's Extensible Messaging and Presence Protocol (XMPP). For further information, see <http://www.xmpp.org/xsf/>.

3. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.

4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://www.xmpp.org/registrar/>.