Network Working Group P. Stickler Internet-Draft Nokia Research Center Expires: July 17, 2002 January 16, 2002 The 'auth:' URI Scheme for Hierarchical Authority Identifiers draft-pstickler-auth-00 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on July 17, 2002. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract This document describes the 'auth:' Uniform Resource Identifier (URI) scheme for hierarchical authority identifiers. The 'auth:' URI scheme belongs to the class of Hierarchical URI Schemes as defined in RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax". Stickler Expires July 17, 2002 [Page 1] Internet-Draft The auth: URI Scheme January 2002 Table of Contents 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. BNF for the 'auth:' URI Scheme . . . . . . . . . . . . . . . . . 3 3. Hierarchical Characteristics of 'auth:' URIs . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . 8 Stickler Expires July 17, 2002 [Page 2] Internet-Draft The auth: URI Scheme January 2002 1. Overview The 'auth:' URI scheme is intended for defining hierarchical identifiers for authorities, to which ownership, control, and/or source of knowledge and information is ascribed. The 'auth:' URI scheme belongs to the class of Hierarchical URI Schemes as defined in RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax" [7] and as such provides for parsing into distinct subcomponents, each constituting a hierarchically distinct level. The hierarchical characteristics of 'auth:' URIs are discussed later in this document. The 'auth:' URI scheme also belongs to the class of URIs known as Uniform Resource Values (URV) which are themselves a subclass of Uniform Resource Primitives (URP), a class of URI which constitutes a "WYSIWYG" URI, one which is not dereferencible to and does not denote another web resource, but constitutes a self-contained resource where the full realization of that resource is expressed in the URI itself. For a full discussion of the properties of URPs and URVs, please see [1]. Familiarity with the concepts defined therein will facilitate the full understanding of this document. Examples: auth://abc.com auth://abc.com/sales/europe/finland auth://cool.net;2001-11-29 auth://john.doe@widgets.org auth://f81d4fae-7dec-11d0-a765-00a0c91e6bf6 auth://f81d4fae-7dec-11d0-a765-00a0c91e6bf6;1996:2001 These examples are provided for illustrative purposes only and do not necessarily constitute actual URIs. See the BNF definition below for an explicit definition of 'auth:' URI syntax. 2. BNF for the 'auth:' URI Scheme This is a BNF-like description of the 'auth:' Uniform Resource Identifier syntax, using the conventions of RFC 822[2], except that "|" is used to designate alternatives, and brackets [] are used around optional or repeated elements. Briefly, literals are quoted with "", optional elements are enclosed in [brackets], and elements may be preceded with * to designate n or more repetitions of the following element; n defaults to 0. This BNF description adopts sub-definitions defined in RFC 1738 "Uniform Resource Locators (URL)" [3]. The definition of UUID is Stickler Expires July 17, 2002 [Page 3] Internet-Draft The auth: URI Scheme January 2002 adopted from the Internet Draft draft-kindel-uuid-uri-00 [6] defining the UUID string representation conforming to ISO-11578 [5] and adopted by RFC 2518 "HTTP Extensions for Distributed Authoring -- WEBDAV" [4]. voc-URI = "auth://" root-authority [ "/" sub-auth-path ] [ dates ] root-authority = ( [ user "@" ] host ) | UUID sub-auth-path = sub-authority *( "/" sub-authority ) sub-authority = 1*uchar dates = ";" start-date [ ":" end-date ] start-date = date end-date = date date = year [ "-" month [ "-" day ] ] year = 4digit month = 2digit day = 2digit ; Sub-definitions adopted from draft-kindel-uuid-uri-00: UUID = 8hex "-" 4hex "-" 4hex "-" 4hex "-" 12hex ; Sub-definitions adopted from RFC 1738: host = hostname | hostnumber hostname = *[ domainlabel "." ] toplabel domainlabel = alphadigit | alphadigit *[ alphadigit | "-" ] alphadigit toplabel = alpha | alpha *[ alphadigit | "-" ] alphadigit hostnumber = digits "." digits "." digits "." digits user = *[ uchar | ";" | "?" | "&" | "=" ] lowalpha = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z" hialpha = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" alpha = lowalpha | hialpha digits = 1*digit alphadigit = alpha | digit safe = "$" | "-" | "_" | "." | "+" extra = "!" | "*" | "'" | "(" | ")" | "," hex = digit | "A" | "B" | "C" | "D" | "E" | "F" | Stickler Expires July 17, 2002 [Page 4] Internet-Draft The auth: URI Scheme January 2002 "a" | "b" | "c" | "d" | "e" | "f" escape = "%" hex hex unreserved = alpha | digit | safe | extra uchar = unreserved | escape 3. Hierarchical Characteristics of 'auth:' URIs The 'auth:' URI scheme belongs to the class of Hierarchical URI Schemes as defined in RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax" [7] and as such provides for parsing into distinct subcomponents, each constituting a hierarchically distinct level. Each 'auth:' URI containing one or more levels beyond the URI authority implies a 'auth:' URI for each level up to and including the authority level, though implied 'auth:' URIs need not have any properties associated with them nor be meaningful to any particular system. The optional suffixed dates are not part of the hierarchical structure of an 'auth:' URI and serve only to qualify a specific 'auth:' URI by limiting its validity or significance to a particular period of time. Note that this dating mechanism provides a means to qualify assertions made by a given authority identified by an 'auth:' URI with a bound period of validity; allowing one to define the precise point in time when a given assertion comes into force and subsequently expires. It also allows for the query selection/ filtering of assertions made by a given authority during a specific period of time. E.g. the following 'auth:' URI auth://abc.com/sales/europe/finland implies all of the following superordinate 'auth:' URIs auth://abc.com/sales/europe auth://abc.com/sales auth://abc.com Note that it is not required that a 'auth:' URI have any levels beyond the first root-authority level. Thus, the 'auth:' URI scheme is suitable both for "flat" authority identifiers as well as for hierarchical identifiers. No special meaning or interpretation is ascribed by this specification to particular 'auth:' URI levels or to the relations Stickler Expires July 17, 2002 [Page 5] Internet-Draft The auth: URI Scheme January 2002 between 'auth:' URI levels other than the following: o each of the levels corresponds to a distinct authority identifier o the authority denoted by the 'auth:' URI for a given level is subordinate in some manner to all authorities denoted by each level 'auth:' URI implied by its hierarchical structure o in a query comparison of two 'auth:' URIs for logical (not lexical) equivalence: * A superordinate 'auth:' query URI without dates is deemed to match all same level and subordinate target URIs with or without dates * An 'auth:' query URI with start-date only is deemed to match all same level or subordinate target URIs with a start-date only where the target start date is equal or later than the query start-date * An 'auth:' query URI with start-date only is deemed to match all same level or subordinate target URIs with both start-date and end-date where the target start date is equal or later than the query start-date and the query start-date is prior to the target end-date * An 'auth:' query URI with both start-date and end-date is deemed to match all same level or subordinate target URIs with only a start-date where the target URI start-date is equal or later than the query start-date and prior to the query end-date * An 'auth:' query URI with both start-date and end-date is deemed to match all same level or subordinate target URIs with both a start-date and an end date where the target URI start-date is equal or later than the query start- date and prior to the query end-date and the target end- date is equal or prior to the query end-date Other, more specialized, URI schemes which are derived from the 'auth:' URI scheme may ascribe more specific interpretations to particular levels implicit in the URI as well as more specific relational semantics between different levels. Note that the URI scheme prefix "auth:" is considered to be a valid URI denoting this URI scheme, though it is not itself a valid URI according to this URI scheme. Stickler Expires July 17, 2002 [Page 6] Internet-Draft The auth: URI Scheme January 2002 4. Security Considerations This document raises no known security issues. References [1] Stickler, P., "An Extended Class Taxonomy of Uniform Resource Identifier Schemes", January 2002, . [2] Crocker, D., "STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES", RFC 822, August 1982. [3] Berners-Lee, T., Masinter, L. and M. McCahill, "Uniform Resource Locators (URL)", RFC 1738, December 1994. [4] Goland, Y., Whitehead, E., Faizi, A., Carter, S. and D. Jensen, "HTTP Extensions for Distributed Authoring -- WEBDAV", RFC 2518, February 1999. [5] International Organization for Standardization, "ISO/IEC 11578:1996 Information technology -- Open Systems Interconnection -- Remote Procedure Call", August 2001. [6] Kindel, C., "The uuid: URI scheme", November 1997, . [7] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. Author's Address Patrick Stickler Nokia Research Center Visiokatu 1 Tampere 33720 FI EMail: patrick.stickler@nokia.com Stickler Expires July 17, 2002 [Page 7] Internet-Draft The auth: URI Scheme January 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. 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Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Stickler Expires July 17, 2002 [Page 8]