RFC 6593
Service Undiscovery Using Hide-and-Go-Seek for the Domain Pseudonym System (DPS)
RFC 6593 ✨ Service Undiscovery Using Hide-and-Go-Seek for the Domain Pseudonym System (DPS)
Okay bestie, first the paperwork 💅 This is an Independent Submission, and it's labelled as an Experimental category document with ISSN 2070-1721. It was written by C. Pignataro, J. Clarke, and G. Salgueiro, all from Cisco Systems, and it's dated 1 April 2012. The date is 1 April, so make of that what you will 👀 It doesn't obsolete or update anything, since the title block doesn't list any RFCs.
Abstract
Service discovery is everywhere now, so curious clients are drowning in service instances and options every time they go browsing 😭 A typical domain might have web servers, remote desktop servers, printers, file servers, video content servers, automatons, Points of Presence using artificial intelligence, etc., all shouting that they exist 📣 Honestly, it's no surprise that some protocols and services want the comfort of anonymity and choose to avoid being discovered 🫶
This memo describes a new experimental protocol for this purpose, using the Domain Pseudonym System (DPS). It also talks about strategies for making it work and deploying it successfully ✨
Status of This Memo
This document is not an Internet Standards Track specification. It's being published for examination, experimental implementation, and evaluation 🧐
It defines an Experimental Protocol for the Internet community. It's a contribution to the RFC Series, independent of any other RFC stream. The RFC Editor chose to publish it at their discretion, and they make no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor aren't candidates for any level of Internet Standard, so see Section 2 of RFC 5741 for the full story 📚
Info about the current status of this document, any errata, and how to give feedback is at http://www.rfc-editor.org/info/rfc6593 🔗
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. 🎀
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) as they stand on the date of publication. Please read these carefully, because they describe your rights and restrictions for this document 💜
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Procedures Using the Domain Pseudonym System . . . . . . . . . 3
2.1. Count to Live (CTL) for IPv4 and Count Limit (CL) for
IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Implicit and Explicit Hiding . . . . . . . . . . . . . . . 4
2.3. Timeout State and Finite State Machine for Misbehaving
Clients . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4. Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.5. Service-as-a-Service (SaaS) Method . . . . . . . . . . . . 5
2.6. Foobar, Mononymous, and other Disguises . . . . . . . . . . 5
2.7. Hinting . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.8. Truth or Dare as Disambiguation . . . . . . . . . . . . . . 7
3. Protocol Definition . . . . . . . . . . . . . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Informative References . . . . . . . . . . . . . . . . . . . . 71. Introduction
Okay so, in today's domains there are services that, by choice, would rather not be advertised 🙈 They want to wrap themselves in a shroud of anonymity. The thing is, protocols just don't address what these services need 😤 So we're proposing a brand new paradigm: service hide-and-go-seek for services that do not want to be discovered 🧚
A client might be out looking for a service, but an apathetic, playful, overwhelmed, or shy service might prefer a hide or hint engagement instead of just showing itself 💀 Main character energy, honestly 💅
1.1. Scope
This document is unscoped, as the scoping service cannot be found. 🫥
2. Procedures Using the Domain Pseudonym System
Some services hide themselves so they won't be found, maybe by clients 👀 The sneaky client trying to find them is called the "seeker" (or, more precisely, "it") 🔍 The concealed service is called the "hider" 🦋 The whole Service Undiscovery process, using hide-and-go-seek, runs on the Domain Pseudonym System (DPS), where a service instance can hide behind a fictitious, fallacious, or facetious name 🎭 For example, a music streaming service might advertise itself as a tax collection agency's web site. Iconic 😭
2.1. Count to Live (CTL) for IPv4 and Count Limit (CL) for IPv6
The hide-and-go-seek process starts with a services "ready or not" sequence, where "it" counts up to a default Count to Live (CTL) or Count Limit (CL) of 50 🎀 Services in hiding can change their hiding names while "it" isn't looking, but each time they do, their CTL (or CL) goes down by one. It is imperative that "it" counts by one (count++) until reaching the CTL or CL 🔢 If "it" tries to skip-count, and this gets discovered, its count is reset to zero 🙅♀️
If a client ("it") tries to peek into a list of services before reaching the CTL, "it" gets placed into a "timeout" state 🚫 In that state "it" is denied access to all services until the hider feels "it" has learned its lesson. Other services may choose to mock "it" while "it" is in "timeout" 💀 Not me laughing 😭
2.2. Implicit and Explicit Hiding
Service hiders have all kinds of strategies so that "it" (the go-seeker) doesn't find them 🙈 Implicit strategies are the most common and also very effective, and they use Silence-as-a-Service (SiaaS) 🤫 Explicit strategies are best shown by the "I am not here" argument 🙅 The service names most commonly used for explicit hiding include:
emptyno%20onegone-fishing/dev/ilinside/dev/iousout-to-lunch/opt/out/opt/ional/vol/atileyou're-not-much-of-a-bloodhound-are-you-Sherlock
Tell me that last one isn't iconic 💅🔥
2.3. Timeout State and Finite State Machine for Misbehaving Clients
As we covered in Section 2.1, if "it" tries to access a hiding service before the CTL (or CL) has expired, "it" gets placed into a "timeout" state and denied access to all services 🚷 While "it" is in that period, if "it" tries to contact any IPv4-based service, the service replies with an ICMPv4 Destination Unreachable message type (1) and a code of "Communication Administratively Prohibited" (13) 📨 An IPv6 service replies with an ICMPv6 Destination Unreachable message type (3) and a code of "communication with destination administratively prohibited" (1) 📨 Services keep replying with these messages until they feel "it" has learned its lesson 🙄
During the "timeout" period, services may also randomly send ICMP insults to "it" 💀 ICMPv4 type 253 (reserved for experimentation [RFC4727]) is used to specify an "Insult" class of messages, and ICMPv6 type 200 (reserved for experimentation [RFC4443]) is used for the same purpose 🔥 Within each type there are three experimental codes, and they are the chef's kiss of roasts 👑
LOSER (code 0): The service wishes to convey that "it" is
incapable of winning
DORK (code 1): The service wants to imply that "it" is
stupid or silly
TODAY IS SPECIAL (code 2): The service intends to respond to the
question "are you always this stupid or
is today a special occasion?"2.4. Echo
Echo, derived from [RFC0862], can also be a super effective hiding technique 🪞 The hider just repeats the service name that another service instance advertises, and makes sure it's in UTF-27 lowercase to convey that it was fading out 🌫️ The hider may also choose to echo the go-seeker's request straight back to the go-seeker, as-is 💜
2.5. Service-as-a-Service (SaaS) Method
This method can be used recursively, and yes, the document really says it like this, nested parentheses and all 🌀
This method can be used recursively (i.e., this method can be used recursively (i.e., this method can be used recursively (i.e., this method can be used recursively))). (See Section 2.5). 🙃
2.6. Foobar, Mononymous, and other Disguises
It's common for services to use mononyms 🌟 There are actually documented use cases of mononyms, like great Brazilian athletes or famous musicians (think Prince, or "the-service-formally-known-as-Prince"), being used as a service 🎤 These are techniques the protocol definition allows for hiding a service ✨ Metasyntactic service names (e.g., foo, bar, foobar, baz, and other aliases) are also among the most evolved hiding techniques 🧠 Hypocorisms, on the other hand, do not hide the service, and they typically lead to confusion 🙃 And if the hiders need government-level security, they can simply respond with service-name-redacted, which basically hands the go-seeker a black bar where the service name would be 🖤🫢
2.7. Hinting 🌡️
Okay so, if a go-seeker asks a hider for its service list, the hider can optionally reply with a GUESS instead 🙈. Then the go-seeker starts asking for specific services using HINT-REQUEST PDUs, and the hider answers with temperature-based HINT-REPLY PDUs that say whether the go-seeker is getting close to finding an available service. It's giving hot-or-cold game 💅🔥. For example, the go-seeker might request a web service, and the hider can respond with WARM or COLD to hint that a related service might be around ✨. A go-seeker may only guess up to 20 times. After that, the go-seeker must reset the CTL/CL before it can guess again 💀. Figure 1 shows the whole flow 👇
"It" Hider
| |
|....."Ready or Not" Sequence.....|
| |
|-------Service List Request----->|
| |
|<-------------GUESS--------------|
| |
|----------HINT-REQUEST---------->|
| [web service] |
| |
|<----------HINT-REPLY------------|
| [COLD] |
| |
|----------HINT-REQUEST---------->|
| [print service] |
| |
|<----------HINT-REPLY------------|
| [FREEZING] |
| |
Figure 1: HintingThis document defines the following HINT types. HINTs are mutually exclusive, so only one can be the vibe at a time 🫶.
ABSOLUTE-ZERO : The seeker is not even close to identifying an
available service
FREEZING : The seeker is remotely close to identifying an
available service
COLD : The seeker is somewhat close to identifying an
available service
WARM : The seeker is fairly close to identifying an
available service
HOT : The seeker is very close to identifying an available
service
BURNING-UP : The seeker is extremely close and is on the verge of
identifying an available serviceNow, geographic weather is super variable, so vendors can add their own HINT types through extensibility 🌍. These might include things like "COLDER THAN A FREEZER IN ANTARCTICA" 🧊😭. New HINT types do not need registration 🌈.
2.8. Truth or Dare as Disambiguation 🎲
Hinting is not truth or dare 🙅♀️. The only challenge "it" has to finish is making guesses to get a service list, and that's it. "It" is also forbidden from asking the hider any personal questions 🙈✨. Boundaries, babe 💅.
3. Protocol Definition 🎀
DPS needs a reliable transport, so it uses TCP 🦋. However, DPS packets (both unicast and omnicast) need to signal their mood as Sneaky ;) [RFC5841] 😏💜.
4. Security Considerations 🔐
Okay, bestie, listen up 😭. Services that nobody discovers are inherently more secure than the ones that get discovered, because they're obscure. BUT the discoverability of a service is pretty much independent of its security characteristics, so don't get it twisted 🚨. Instead, an implementor is guided to [RFC3514] to denote evilness (and the associated security) status 😈. Since [RFC3514] only defines evil and non-evil intent for packets, this document suggests adding an "I am not sure" value for the evil bit 🤷♀️. The intentional ambiguity of this extra state makes it a perfect third value for a binary bit 👑🔥.
5. IANA Considerations 🧚
IANA is strongly encouraged to look the other way and pretend they know nothing about this 🙈💀. This document uses values that IANA reserved for experimentation 🧪. It uses ICMPv4 type 253 and ICMPv6 type 200 for "Insult", with three experimental codes in each: "LOSER" (0), "DORK" (1), and "TODAY IS SPECIAL" (2) 💅. After the experimental phase, well-known hiding names like "gone-fishing", "foobar", "service-name-redacted", and everything else listed throughout this document could be reserved 🌸. Famous stage names and Three-Letter Acronyms (TLAs) [RFC5513] could also get reserved 🌟. Lastly, IANA is begged to reserve the "I am not sure" value for the evil bit 🥺🙏.
6. Acknowledgments 🫶
The authors of this memo and all of their pseudonyms do not make any claims on the originality of the ideas described here 👑. Iconic humility, honestly 💖.
7. Informative References 📚
- [RFC0862] Postel, J., "Echo Protocol", STD 20, RFC 862, May 1983. 🏓
- [RFC3514] Bellovin, S., "The Security Flag in the IPv4 Header", RFC 3514, April 1 2003. 🚩
- [RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC 4443, March 2006. 🧾
- [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. 🧪
- [RFC5513] Farrel, A., "IANA Considerations for Three Letter Acronyms", RFC 5513, April 1 2009. 🔤
- [RFC5841] Hay, R. and W. Turkal, "TCP Option to Denote Packet Mood", RFC 5841, April 1 2010. 🌈
Authors' Addresses 💌
Carlos Pignataro
Cisco Systems
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
US
EMail: cpignata@cisco.com
Joe Clarke
Cisco Systems
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
US
EMail: jclarke@cisco.com
Gonzalo Salgueiro
Cisco Systems
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
US
EMail: gsalguei@cisco.com📦 where this page comes from
- ietf: rfc6593 2012-04
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms