From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc8160.txt | 227 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 doc/rfc/rfc8160.txt (limited to 'doc/rfc/rfc8160.txt') diff --git a/doc/rfc/rfc8160.txt b/doc/rfc/rfc8160.txt new file mode 100644 index 0000000..d282ab9 --- /dev/null +++ b/doc/rfc/rfc8160.txt @@ -0,0 +1,227 @@ + + + + + + +Internet Engineering Task Force (IETF) S. Tatham +Request for Comments: 8160 PuTTY +Category: Standards Track D. Tucker +ISSN: 2070-1721 OpenSSH + April 2017 + + + IUTF8 Terminal Mode in Secure Shell (SSH) + +Abstract + + This document specifies a new opcode in the Secure Shell terminal + modes encoding. The new opcode describes the widely used IUTF8 + terminal mode bit, which indicates that terminal I/O uses UTF-8 + character encoding. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc8160. + +Copyright Notice + + Copyright (c) 2017 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) 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. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + + + + + +Tatham & Tucker Standards Track [Page 1] + +RFC 8160 IUTF8 Terminal Mode in SSH April 2017 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Conventions Used in This Document . . . . . . . . . . . . . . 2 + 3. New IUTF8 Opcode for Terminal Mode Encoding . . . . . . . . . 2 + 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 + 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 6.1. Normative References . . . . . . . . . . . . . . . . . . 3 + 6.2. Informative References . . . . . . . . . . . . . . . . . 3 + Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 4 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 + +1. Introduction + + The Secure Shell (SSH) connection protocol [RFC4254] provides an + encoding for terminal modes, used in the "pty-req" channel request + type. + + A commonly used terminal mode is IUTF8, which indicates that the + terminal driver should assume that terminal I/O uses the UTF-8 + character encoding [RFC3629]. This is typically used by the kernel's + terminal driver on the server to decide how many bytes of input to + treat as a single logical character during line editing. + + SSH does not currently provide an encoding for IUTF8. This document + specifies one. + +2. Conventions Used in This Document + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [RFC2119]. + +3. New IUTF8 Opcode for Terminal Mode Encoding + + The opcode value 42 is defined for the IUTF8 terminal mode. + + As specified in Section 8 of [RFC4254], all opcodes in the range 1 to + 159 have a single uint32 argument; therefore, the IUTF8 opcode is + followed by a single uint32 argument. The value 0 indicates that the + IUTF8 mode is disabled, and the value 1 indicates that it is enabled. + + As with all other encoded terminal modes, the client SHOULD transmit + a value for this mode if it knows about one, and the server MAY + ignore it. + + + + + +Tatham & Tucker Standards Track [Page 2] + +RFC 8160 IUTF8 Terminal Mode in SSH April 2017 + + +4. IANA Considerations + + This document augments the list of "Pseudo-Terminal Encoded Terminal + Modes" defined in Section 8 of [RFC4254]. + + IANA has added the following opcode to the "Pseudo-Terminal Encoded + Terminal Modes" registry: + + opcode mnemonic description + ------ -------- ----------- + 42 IUTF8 Terminal input and output is assumed to be + encoded in UTF-8. + +5. Security Considerations + + The security considerations of [RFC4254] apply. This additional + terminal mode encoding is believed to have no security implications + differing from the existing set of encoded terminal modes. + + Since the IUTF8 terminal mode is intended for use in conjunction with + the UTF-8 character encoding, the security considerations of + [RFC3629] also apply to systems in which this mode is enabled. In + particular, terminal drivers that interpret this bit as enabling + UTF-8-aware line-editing behavior should carefully consider how that + behavior will treat illegal sequences, overlong encodings, and + redundant representations of composed characters (see [UNICODE]). + +6. References + +6.1. 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, + . + + [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO + 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November + 2003, . + + [RFC4254] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) + Connection Protocol", RFC 4254, DOI 10.17487/RFC4254, + January 2006, . + +6.2. Informative References + + [UNICODE] The Unicode Consortium, "The Unicode Standard", + . + + + +Tatham & Tucker Standards Track [Page 3] + +RFC 8160 IUTF8 Terminal Mode in SSH April 2017 + + +Acknowledgements + + The authors are indebted to Colin Watson for originally suggesting + this terminal mode in 2005, and David Madore and Jakub Jelen for + prior implementation efforts. + +Authors' Addresses + + Simon Tatham + PuTTY + + Email: anakin@pobox.com + + + Darren Tucker + OpenSSH + + Email: dtucker@openssh.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Tatham & Tucker Standards Track [Page 4] + -- cgit v1.2.3