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Independent Submission                                       R. HartmannRequest for Comments: 7194                                   August 2014Updates:1459Category: InformationalISSN: 2070-1721Default Port for Internet Relay Chat (IRC) via TLS/SSLAbstract   This document describes the commonly accepted practice of listening   on TCP port 6697 for incoming Internet Relay Chat (IRC) connections   encrypted via TLS/SSL.Status of This Memo   This document is not an Internet Standards Track specification; it is   published for informational purposes.   This is a contribution to the RFC Series, independently of any other   RFC stream.  The RFC Editor has chosen to publish this document at   its discretion and makes no statement about its value for   implementation or deployment.  Documents approved for publication by   the RFC Editor are not a candidate for any level of Internet   Standard; seeSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc7194.Copyright Notice   Copyright (c) 2014 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 78 and the IETF Trust's Legal   Provisions Relating to IETF Documents   (http://trustee.ietf.org/license-info) in effect on the date of   publication of this document.  Please review these documents   carefully, as they describe your rights and restrictions with respect   to this document.Hartmann                      Informational                     [Page 1]

RFC 7194            Default Port for IRC via TLS/SSL         August 2014Table of Contents1. Rationale .......................................................22. Technical Details ...............................................22.1. Connection Establishment ...................................22.2. Certificate Details ........................................32.2.1. Server Certificate ..................................32.2.2. Client Certificate ..................................33. Security Considerations .........................................34. IANA Considerations .............................................45. Normative References ............................................46. Informative References ..........................................47. Acknowledgements ................................................5Appendix A. Supporting Data ........................................61.  Rationale   Although system port assignments exist for IRC traffic that is plain   text (TCP/UDP port 194) or TLS/SSL encrypted (TCP/UDP port 994)   [IANALIST], it is common practice amongst IRC networks not to use   them for reasons of convenience and general availability on systems   where no root access is granted or desired.   IRC networks have defaulted to listening on TCP port 6667 for plain   text connections for a considerable time now.  This is covered by the   IRCU assignment of TCP/UDP ports 6665-6669.   Similar consensus has been reached within the IRC community about   listening on TCP port 6697 for incoming IRC connections encrypted via   TLS/SSL [RFC5246].2.  Technical Details2.1.  Connection Establishment   An IRC client connects to an IRC server.  Immediately after that, a   normal TLS/SSL handshake takes place.  Once the TLS/SSL connection   has been established, a normal IRC connection is established via the   tunnel.  Optionally, the IRC server may set a specific user mode   (umode) for the client, marking it as using TLS/SSL.  Again,   optionally, an IRC server might offer the option to create channels   in such a way that only clients connected via TLS/SSL may join.   For details on how IRC works, see [RFC1459], [RFC2810], [RFC2811],   [RFC2812], and [RFC2813].  Please note that IRC is extremely   fragmented, and implementation details can vary wildly.  Most   implementations regard the latter RFCs as suggestions, not as   binding.Hartmann                      Informational                     [Page 2]

RFC 7194            Default Port for IRC via TLS/SSL         August 20142.2.  Certificate Details2.2.1.  Server Certificate   The IRC server's certificate should be issued by a commonly trusted   certification authority (CA).   The Common Name should match the Fully Qualified Domain Name (FQDN)   of the IRC server or have appropriate wildcards, if applicable.   The IRC client should verify the certificate.2.2.2.  Client Certificate   If the client is using a certificate as well, it should be issued by   a commonly trusted CA or a CA designated by the IRC network.   The certificate's Common Name should match the main IRC nickname.   If the network offers nick registration, this nick should be used.   If the network offers grouped nicks, the main nick or account name   should be used.   If the network offers nick registration, the client certificate   should be used to identify the user against the nick database.  See   [CERTFP] for a possible implementation.3.  Security Considerations   The lack of a common, well-established listening port for IRC via   TLS/SSL could lead to end users being unaware of their IRC network of   choice supporting TLS/SSL.  Thus, they might not use encryption even   if they wanted to.   It should be noted that this document merely describes client-to-   server encryption.  There are still other attack vectors like   malicious administrators, compromised servers, insecure server-to-   server communication, channels that do not enforce encryption for all   channel members, malicious clients, or comprised client machines on   which logs are stored.   Those attacks can by their very nature not be addressed by client-to-   server encryption.  Additional safeguards are needed if a user fears   any of the threats above.Hartmann                      Informational                     [Page 3]

RFC 7194            Default Port for IRC via TLS/SSL         August 2014   This document does not address server links as there are no commonly   accepted ports or even back-end protocols.  Ports and back-end   protocols are normally established in a bilateral agreement.  All   operators are encouraged to use strong encryption for back-end   traffic, no matter if they offer IRC via TLS/SSL to end users.4.  IANA Considerations   An assignment of TCP port 6697 for IRC via TLS/SSL has been made.   The service name is "ircs-u" and the description "Internet Relay Chat   via TLS/SSL":   ircs-u  6697/tcp       Internet Relay Chat via TLS/SSL5.  Normative References   [RFC1459]  Oikarinen, J. and D. Reed, "Internet Relay Chat Protocol",RFC 1459, May 1993.   [RFC2810]  Kalt, C., "Internet Relay Chat: Architecture",RFC 2810,              April 2000.   [RFC2811]  Kalt, C., "Internet Relay Chat: Channel Management",RFC2811, April 2000.   [RFC2812]  Kalt, C., "Internet Relay Chat: Client Protocol",RFC2812, April 2000.   [RFC2813]  Kalt, C., "Internet Relay Chat: Server Protocol",RFC2813, April 2000.   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security              (TLS) Protocol Version 1.2",RFC 5246, August 2008.6.  Informative References   [IANALIST] IANA, "Service Name and Transport Protocol Port Number              Registry", <http://www.iana.org/assignments/service-names-port-numbers>.   [TOP100]   netsplit.de, "IRC Networks - Top 100",              <http://irc.netsplit.de/networks/top100.php>.   [MAVERICK] netsplit.de, "IRC Networks - in alphabetical order",              <http://irc.netsplit.de/networks/lists.php?query=maverick>.Hartmann                      Informational                     [Page 4]

RFC 7194            Default Port for IRC via TLS/SSL         August 2014   [CERTFP]   The Open and Free Technology Community, "OFTC -              NickServ/CertFP",              <http://www.oftc.net/oftc/NickServ/CertFP>.7.  Acknowledgements   Thanks go to the IRC community at large for reaching a consensus.   Special thanks go to the IRC operators who were eager to support port   6697 on their respective networks.   Special thanks also go to Nevil Brownlee and James Schaad for working   on this document in their capacities as Independent Submissions   Editor and Reviewer, respectively.Hartmann                      Informational                     [Page 5]

RFC 7194            Default Port for IRC via TLS/SSL         August 2014Appendix A.  Supporting Data   As of October 2010, out of the top twenty IRC networks [TOP100]   [MAVERICK], ten support TLS/SSL.  Only one of those networks does not   support TLS/SSL via port 6697 and has no plans to support it.  All   others supported it already or are supporting it since being   contacted by the author.  A more detailed analysis is available but   does not fit within the scope of this document.Authors' Address   Richard Hartmann   Munich   Germany   EMail: richih.mailinglist@gmail.com   URI:http://richardhartmann.deHartmann                      Informational                     [Page 6]