Identification Protocol
RFC 1413
Document | Type |
RFC - Proposed Standard
(February 1993; Errata)
Obsoletes RFC 931
|
|
---|---|---|---|
Author | Michael StJohns | ||
Last updated | 2020-01-21 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1413 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group M. St. Johns Request for Comments: 1413 US Department of Defense Obsoletes: 931 February 1993 Identification Protocol Status of this Memo This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited. 1. INTRODUCTION The Identification Protocol (a.k.a., "ident", a.k.a., "the Ident Protocol") provides a means to determine the identity of a user of a particular TCP connection. Given a TCP port number pair, it returns a character string which identifies the owner of that connection on the server's system. The Identification Protocol was formerly called the Authentication Server Protocol. It has been renamed to better reflect its function. This document is a product of the TCP Client Identity Protocol Working Group of the Internet Engineering Task Force (IETF). 2. OVERVIEW This is a connection based application on TCP. A server listens for TCP connections on TCP port 113 (decimal). Once a connection is established, the server reads a line of data which specifies the connection of interest. If it exists, the system dependent user identifier of the connection of interest is sent as the reply. The server may then either shut the connection down or it may continue to read/respond to multiple queries. The server should close the connection down after a configurable amount of time with no queries - a 60-180 second idle timeout is recommended. The client may close the connection down at any time; however to allow for network delays the client should wait at least 30 seconds (or longer) after a query before abandoning the query and closing the connection. St. Johns [Page 1] RFC 1413 Identification Protocol February 1993 3. RESTRICTIONS Queries are permitted only for fully specified connections. The query contains the local/foreign port pair -- the local/foreign address pair used to fully specify the connection is taken from the local and foreign address of query connection. This means a user on address A may only query the server on address B about connections between A and B. 4. QUERY/RESPONSE FORMAT The server accepts simple text query requests of the form: <port-on-server> , <port-on-client> where <port-on-server> is the TCP port (decimal) on the target (where the "ident" server is running) system, and <port-on-client> is the TCP port (decimal) on the source (client) system. N.B - If a client on host A wants to ask a server on host B about a connection specified locally (on the client's machine) as 23, 6191 (an inbound TELNET connection), the client must actually ask about 6191, 23 - which is how the connection would be specified on host B. For example: 6191, 23 The response is of the form <port-on-server> , <port-on-client> : <resp-type> : <add-info> where <port-on-server>,<port-on-client> are the same pair as the query, <resp-type> is a keyword identifying the type of response, and <add-info> is context dependent. The information returned is that associated with the fully specified TCP connection identified by <server-address>, <client-address>, <port-on-server>, <port-on-client>, where <server-address> and <client-address> are the local and foreign IP addresses of the querying connection -- i.e., the TCP connection to the Identification Protocol Server. (<port-on-server> and <port-on-client> are taken from the query.) For example: 6193, 23 : USERID : UNIX : stjohns 6195, 23 : ERROR : NO-USER St. Johns [Page 2] RFC 1413 Identification Protocol February 1993 5. RESPONSE TYPES A response can be one of two types: USERID In this case, <add-info> is a string consisting of an operating system name (with an optional character set identifier), followed by ":", followed by an identification string. The character set (if present) is separated from the operating system name by ",". The character set identifier is used to indicate the character set of the identification string. The character set identifier, if omitted, defaults to "US-ASCII" (see below). Permitted operating system names and character set names are specified in RFC 1340, "Assigned Numbers" or its successors. In addition to those operating system and character set names specified in "Assigned Numbers" there is oneShow full document text