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/rfc933.txt | 228 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) create mode 100644 doc/rfc/rfc933.txt (limited to 'doc/rfc/rfc933.txt') diff --git a/doc/rfc/rfc933.txt b/doc/rfc/rfc933.txt new file mode 100644 index 0000000..db85b33 --- /dev/null +++ b/doc/rfc/rfc933.txt @@ -0,0 +1,228 @@ + + +Network Working Group S. Silverman +Request for Comments: 933 MITRE-Washington + January 1985 + + OUTPUT MARKING TELNET OPTION + + +Status of this Memo + + This RFC proposes a new option for Telnet for the ARPA-Internet + community, and requests discussion and suggestions for improvements. + Distribution of this memo is unlimited. + +Overview + + This proposed option would allow a Server-Telnet to send a banner to + a User-Telnet so that this banner would be displayed on the + workstation screen independently of the application software running + in the Server-Telnet. + +1. Command Name and Code + + OUTMRK 27 + +2. Command Meanings + + IAC WILL OUTMRK + + Sender is willing to send output marking information in a + subsequent sub-negotiation. + + IAC WON'T OUTMRK + + Sender refuses to send output marking information. + + IAC DO OUTMRK + + Sender is willing to receive output marking information in a + subsequent sub-negotiation. + + IAC DON'T OUTMRK + + Sender refuses to accept output marking information. + + IAC SB OUTMRK CNTL data IAC SE + + The sender requests receiver to use the data in this + subnegotiation as a marking for the normally transmitted Telnet + data until further notice. The CNTL octet indicates the position + of the marking (see below). + + + +Silverman [Page 1] + + + +RFC 933 January 1985 +Output Marking Telnet Option + + + IAC SB OUTMRK ACK IAC SE + + The sender acknowledges the data and agrees to use it to perform + output marking (see below). + + IAC SB OUTMRK NAK IAC SE + + The sender objects to using the data to perform output marking + (see below). + +3. Default + + WON'T OUTMRK + + Output marking information will not be exchanged. + + DON'T OUTMRK + + Output marking information will not be exchanged. + +4. Motivation for the Option + + The security architecture of some military systems identifies a + security level with each Telnet connection. There is a corresponding + need to display a security banner on visual display devices. + (Reference: Department of Defense Trusted Computer System Evaluation + Criteria, Section 3.1.1.3.2.3, Labeling Human-Readable Output.) + + The output marking is currently done by transmitting the banner as + data within each screen of data. It would be more efficient to + transmit the data once with instructions and have User-Telnet + maintain the banner automatically without any additional + Server-Telnet action. This frees Server-Telnet from needing to know + the output device page size. + + Under this proposal Server-Telnet would send an option sequence with + the command, a control flag, and the banner to be used. While + current systems use the top of the screen, it is conceivable other + systems would want to put the banner at the bottom or perhaps even + the side of the screen. This is the reason for the control flag. + +5. Description of the Option + + Either side of the session can initiate the option; however, normally + it will be the server side that initiates the request to perform + output marking. Either the Server-Telnet sends "WILL OUTMRK" or the + User-Telnet sends a "DO OUTMRK". The party receiving the initial + + +Silverman [Page 2] + + + +RFC 933 January 1985 +Output Marking Telnet Option + + + "WILL" (or "DO") would respond with "DO" (or "WILL") to accept the + option. Then Server-Telnet responds with the marking data. The + format of this is: + + "IAC SB OUTMRK CNTL data IAC SE" + + CNTL is the Control Flag described below, + the data is in ASCII. + + If this is satisfactory, User-Telnet responds: + + "IAC SB OUTMRK ACK IAC SE" + + ACK is the ASCII ACK (6). + + From this point, User-Telnet will have to translate any command which + uses cursor controls so that the application data is mapped to the + application part of the screen. + + If the data passed in the subnegotiation field is unacceptable to + User-Telnet, then it responds with: + + "IAC SB OUTMRK NAK IAC SE" + + NAK is the ASCII NAK (21). + + It is now up to Server-Telnet to start the sequence over again and + use "more acceptable" data (or possibly take other action such as + connection termination). + + To terminate output marking, Server-Telnet transmits "WON'T OUTMRK". + + If necessary, User-Telnet would notify Server-Telnet about the new + effective page size. User-Telnet would then map the output data to + the allowed usable space on the screen. + + User-Telnet may request OUTMRK data or initiate setup of this + convention at anytime by transmitting "DO OUTMRK". If a WILL, DO + OUTMRK exchange is not followed by the OUTMRK subnegotiation of the + marking data, the User-Telnet may terminate the output marking option + by sending a "DON'T OUTMRK". + + + + + + + + +Silverman [Page 3] + + + +RFC 933 January 1985 +Output Marking Telnet Option + + + Control Flag + + The CNTL flag is defined as: + + D = Default, the placement of the markings is up to + User-Telnet. This is the expected mode for most + interactions. + + T = Top, this banner is to be used as the top of the screen. + If multiple output markings are desired, then T and B (or R + & L ) are to be used. + + B = Bottom, this banner is to be used at the bottom of the + screen. + + L = Left, markings on the left. (The precise meaning of this + is to be defined.) + + R = Right, marking on right. (The precise meaning of this is + to be defined.) + + Banner Data + + The use of Carriage Return and Line Feed (CRLF) will be + interpreted as a end of line in the marking banner text. If the + user wants a multiline banner, CRLF will be used between each + line. No CRLF is needed at the end of the marking data. + + To use multiple banners, all of the banners will be included in + one subnegotiation command of the form: + + "IAC SB OUTMRK CNTL data GS CNTL data IAC SE" + + where GS is the ASCII Group Separator (29) character. + + User-Telnet will be responsible for positioning the marking banner + data on the screen. + + + + + + + + + + + + +Silverman [Page 4] + -- cgit v1.2.3