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/rfc4709.txt | 843 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 843 insertions(+) create mode 100644 doc/rfc/rfc4709.txt (limited to 'doc/rfc/rfc4709.txt') diff --git a/doc/rfc/rfc4709.txt b/doc/rfc/rfc4709.txt new file mode 100644 index 0000000..fb1a5ab --- /dev/null +++ b/doc/rfc/rfc4709.txt @@ -0,0 +1,843 @@ + + + + + + +Network Working Group J. Reschke +Request for Comments: 4709 greenbytes +Category: Informational October 2006 + + + Mounting Web Distributed Authoring and Versioning (WebDAV) Servers + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2006). + +Abstract + + In current Web browsers, there is no uniform way to specify that a + user clicking on a link will be presented with an editable view of a + Web Distinguished Authoring and Versioning (WebDAV) server. For + example, it is frequently desirable to be able to click on a link and + have this link open a window that can handle drag-and-drop + interaction with the resources of a WebDAV server. + + This document specifies a mechanism and a document format that + enables WebDAV servers to send "mounting" information to a WebDAV + client. The mechanism is designed to work on any platform and with + any combination of browser and WebDAV client, relying solely on the + well-understood dispatch of documents through their MIME type. + + + + + + + + + + + + + + + + + + + + +Reschke Informational [Page 1] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +Table of Contents + + 1. Introduction ....................................................2 + 2. Terminology .....................................................3 + 3. Format ..........................................................3 + 3.1. dm:mount ...................................................4 + 3.2. dm:url .....................................................4 + 3.3. dm:open ....................................................4 + 3.4. dm:username ................................................4 + 4. Example .........................................................4 + 5. Internationalization Considerations .............................5 + 6. IANA Considerations .............................................6 + 6.1. MIME Type Registration .....................................6 + 7. Security Considerations .........................................8 + 8. Acknowledgements ................................................8 + 9. References ......................................................9 + 9.1. Normative References .......................................9 + 9.2. Informative References .....................................9 + Appendix A. Alternative Approaches ...............................10 + A.1. ...Through HTML/CSS Extensions ............................10 + A.2. ...Through Custom URI Schemes .............................10 + Appendix B. Implementations ......................................10 + B.1. Example Implementation for Webfolder Client ...............10 + B.2. Xythos ....................................................14 + +1. Introduction + + By definition, a Web Distributed Authoring and Versioning (WebDAV) + server ([RFC2518]) is an HTTP server as well ([RFC2616]). Most + WebDAV servers can be (at least partly) operated from an HTML-based + user interface in a web browser. However, it is frequently desirable + to be able to switch from an HTML-based view to a presentation + provided by a native WebDAV client, directly supporting the authoring + features defined in WebDAV and related specifications. + + This document specifies a platform-neutral mechanism based on the + dispatch of documents through their MIME type. For completeness, + Appendix A lists other approaches that have been implemented in + existing clients. + + For example, many educational institutions use WebDAV servers as a + mechanism for sharing documents among students. Each student owns a + separate collection structure on a WebDAV server, often called his/ + her "locker". Ideally, when users click on a link in an HTML page + provided by the university (perhaps by their university Web portal), + an editable view of their locker will appear. + + + + + +Reschke Informational [Page 2] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +2. Terminology + + The terminology used here follows that in the WebDAV Distributed + Authoring Protocol specification [RFC2518]. + + 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]. + + This document uses XML DTD fragments ([XML]) as a purely notational + convention. In particular: + + o Element names use the namespace + "http://purl.org/NET/webdav/mount". When an XML element type in + this namespace is referenced in this document outside of the + context of an XML fragment, the string "dm:" will be prefixed to + the element name. + + o Element ordering is irrelevant. + + o Extension elements/attributes (elements/attributes not already + defined as valid child elements) may be added anywhere, except + when explicitly stated otherwise. + +3. Format + + A WebDAV mount request is encoded in a specific XML format ([XML]) + with a well-defined MIME type (see Section 6.1). The MIME type + allows user agents to dispatch the content to a handler specific to + the system's WebDAV client. + + The elements defined below use the namespace + "http://purl.org/NET/webdav/mount". + + + + + + + + + + + + + + + + +Reschke Informational [Page 3] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +3.1. dm:mount + + The element acts as a container for all the remaining + elements defined by this protocol. + +3.2. dm:url + + The mandatory element provides the HTTP URL of the WebDAV + collection that should be mounted by the client. + +3.3. dm:open + + The optional element instructs the client to display the + specified child collection; its URL is computed by concatenating this + element's value with the URL obtained from the (Section 3.2) + element (see Section 7 for a discussion about why this element only + supports displaying collections rather than opening arbitrary + documents). + +3.4. dm:username + + The server can use the optional element to specify the + name of the currently authenticated principal. A client can use this + value to select a matching mount point (different users may have + mounted the URL with different credentials under different local + mount points) or to provide a meaningful default for authentication + against the server. It is common that a browser and WebDAV client do + not share HTTP connections, so including this information in the + mount document increases usability. + + Implementation Note: If a element is present, public + caching of the document should be disallowed. Thus, appropriate + 'Vary' or 'Cache-Control' headers are needed in the server response. + +4. Example + + In the example below, the client first retrieves a representation of + a WebDAV collection using a generic Web browser (1). The returned + HTML content contains a hyperlink that identifies the "davmount" + document in the format defined in Section 3 (2). The user follows + this link (3), which causes the server to return the "davmount" + document to the user's browser (4). The browser in turn passes the + content to the application that was registered to handle the + "application/davmount+xml" MIME type, usually the default WebDAV + client on the client's system. + + + + + + +Reschke Informational [Page 4] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + (1) Client retrieves representation of WebDAV collection "/user42/ + inbox/". + + GET /user42/inbox/ HTTP/1.1 + Host: www.example.com + + (2) Server returns representation. + + HTTP/1.1 200 OK + Content-Type: text/html + Content-Length: xxx + + .. + View this collection in your + WebDAV client + .. + + (note that the example shows only that part of the HTML page that + contains the relevant link) + + (3) Client follows link to "davmount" document + + GET /user42/inbox/?action=davmount HTTP/1.1 + Host: www.example.com + + (4) Server returns "davmount" document + + HTTP/1.1 200 OK + Content-Type: application/davmount+xml + Content-Length: xxx + Cache-Control: private + + + http://www.example.com/user42/ + inbox/ + + +5. Internationalization Considerations + + This document does not introduce any new internationalization + considerations beyond those discussed in [RFC2518], Section 16. + + + + + + + + + + +Reschke Informational [Page 5] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +6. IANA Considerations + +6.1. MIME Type Registration + + Type name: + + application + + Subtype name: + + davmount+xml + + Required parameters: + + none + + Optional parameters: + + "charset": This parameter has identical semantics to the charset + parameter of the "application/xml" media type as specified in + [RFC3023]. + + Encoding considerations: + + Identical to those of "application/xml" as described in [RFC3023], + Section 3.2. + + Security considerations: + + As defined in this specification. In addition, as this media type + uses the "+xml" convention, it shares the same security + considerations as described in [RFC3023], Section 10. + + Interoperability considerations: + + There are no known interoperability issues. + + Published specification: + + This specification. + + Applications that use this media type: + + SAP Netweaver Knowledge Management, Xythos Drive. + + + + + + + +Reschke Informational [Page 6] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + Additional information: + + Magic number(s): + + As specified for "application/xml" in [RFC3023], Section 3.2. + + File extension(s): + + .davmount + + Fragment identifiers: + + As specified for "application/xml" in [RFC3023], Section 5. + + Base URI: + + As specified in [RFC3023], Section 6. + + Macintosh file type code(s): + + TEXT + + Person & email address to contact for further information: + + Julian Reschke + + Intended usage: + + COMMON + + Restrictions on usage: + + None. + + Author: + + Julian Reschke + + Change controller: + + IESG + + + + + + + + + + +Reschke Informational [Page 7] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +7. Security Considerations + + All security considerations connected to HTTP/WebDAV and XML apply + for this specification as well, namely, [RFC2518] (Section 17) and + [RFC3470] (Section 7). + + In addition, client implementers must be careful when implementing + the element (see Section 3.3). It MUST NOT be used to + initiate any action beyond displaying the contents of a WebDAV + collection (supporting "opening" documents could be abused to trick a + user into letting the operating system's shell execute arbitrary + content, possibly running it as an executable program). + + The OPTIONAL element defined in Section 3.4 allows the + inclusion of user names into mount documents. However in some cases, + user name information is considered to be security sensitive. Should + this be the case, parties generating mount documents are advised to + either not to include user names, or to use access control to + restrict access to the information as desired. + +8. Acknowledgements + + This document has benefited from thoughtful discussion by Emile + Baizel, Spencer Dawkins, Lisa Dusseault, Stefan Eissing, Joe + Gregorio, Michal Gregr, Russ Housley, Jim Luther, Jaroslav Mazanec, + and Jim Whitehead. + + + + + + + + + + + + + + + + + + + + + + + + + +Reschke Informational [Page 8] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +9. References + +9.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D. + Jensen, "HTTP Extensions for Distributed Authoring -- + WEBDAV", RFC 2518, February 1999. + + [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., + Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext + Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. + + [RFC3023] Murata, M., St.Laurent, S., and D. Kohn, "XML Media + Types", RFC 3023, January 2001. + + [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform + Resource Identifier (URI): Generic Syntax", STD 66, + RFC 3986, January 2005. + + [XML] Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and + F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fourth + Edition)", W3C REC-xml-20060816, August 2006, + . + +9.2. Informative References + + [RFC3470] Hollenbeck, S., Rose, M., and L. Masinter, "Guidelines for + the Use of Extensible Markup Language (XML) within IETF + Protocols", RFC 3470, BCP 70, January 2003. + + [WEBARCH] Walsh, N. and I. Jacobs, "Architecture of the World Wide + Web, Volume One", W3C REC-webarch-20041215, December 2004, + . + + + + + + + + + + + + + + + +Reschke Informational [Page 9] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +Appendix A. Alternative Approaches + +A.1. ...Through HTML/CSS Extensions + + Microsoft Internet Explorer implements a Cascading Style Sheet (CSS) + extension that allows switching to its own WebDAV client + ("Webfolder", see ). However, at the time of + this writing, this extension was not implemented by any other user + agent. + +A.2. ...Through Custom URI Schemes + + The "kio" library of the "K Desktop Enviroment" + () uses the URI scheme "webdav" to dispatch to + the system's WebDAV client. This URI scheme is not registered, nor + is it supported on other platforms. Furthermore, the W3C's + "Architecture of the World Wide Web, Volume One" explicitly advises + against defining new schemes when existing schemes can be used: + + A specification SHOULD reuse an existing URI scheme (rather than + create a new one) when it provides the desired properties of + identifiers and their relation to resources. + + (See [WEBARCH], Section 2.4.) + +Appendix B. Implementations + +B.1. Example Implementation for Webfolder Client + + The figure below shows a sample implementation of a dispatcher for + the application/davmount+xml datatype, suited for Win32 systems and + the Microsoft "Webfolder" client. + + // sample implementation of application/davmount+xml + // dispatcher for Windows Webfolder client + // + // to install/uninstall: + // wscript davmount.js + // + // to open the webfolder: + // wscript davmount.js filename + // (where filename refers to an XML document with MIME type + // application/davmount+xml) + + var EXTENSION = ".davmount"; + var MIMETYPE = "application/davmount+xml"; + var REGKW = "WebDAV.mount"; + + + +Reschke Informational [Page 10] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + var NS = "xmlns:m='http://purl.org/NET/webdav/mount"; + + // remove keys/entries from the registry + + function regdel(shell, key) { + try { + var x = shell.RegRead(key); + try { + shell.RegDelete(key); + } + catch(e) { + WScript.Echo("Error removing key " + key + ": " + e); + } + } + catch(e) { + // entry not present + } + } + + + // methods for registering/unregistering the handler + + function install() { + + var WshShell = new ActiveXObject("WScript.Shell"); + if (WshShell == null) { + WScript.Echo("Couldn't instantiate WScript.Shell object"); + return 2; + } + + var fso = new ActiveXObject("Scripting.FileSystemObject"); + + var RegExt = "HKCR\\" + EXTENSION + "\\"; + var RegMimeType = "HKCR\\MIME\\DataBase\\Content Type\\" + + MIMETYPE + "\\"; + var RegKw = "HKCR\\" + REGKW + "\\"; + + var extension = null; + try { + extension = WshShell.RegRead(RegMimeType + "Extension"); + } + catch (e) { + } + + if (extension == null) { + var but = WshShell.popup("Install the dispatcher for mime type " + + MIMETYPE + "?", 0, MIMETYPE + " installation", 4); + + + + +Reschke Informational [Page 11] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + if (but == 6) { + try { + WshShell.RegWrite(RegExt, REGKW); + WshShell.RegWrite(RegExt + "Content Type", MIMETYPE); + WshShell.RegWrite(RegMimeType + "Extension", EXTENSION); + WshShell.RegWrite(RegKw, "WebDAV Mount Request"); + WshShell.RegWrite(RegKw + "DefaultIcon\\", + "shell32.dll,103"); + var path = fso.getAbsolutePathName("davmount.js"); + WshShell.RegWrite(RegKw + "shell\\open\\command\\", + "%SystemRoot%\\system32\\wscript.exe /nologo \"" + + path + "\" \"%1\"", "REG_EXPAND_SZ"); + } + catch (e) { + WScript.Echo("Error writing to registry"); + return 1; + } + + return 0; + } + else { + return 1; + } + } + else { + var but = WshShell.popup("Remove the dispatcher for mime type " + + MIMETYPE + "?", 0, MIMETYPE + " installation", 4); + + if (but == 6) { + regdel(WshShell, RegExt + "Content Type"); + regdel(WshShell, RegExt); + regdel(WshShell, RegKw + "shell\\open\\command\\"); + regdel(WshShell, RegKw + "DefaultIcon\\"); + regdel(WshShell, RegKw); + regdel(WshShell, RegMimeType + "Extension"); + regdel(WshShell, RegMimeType); + return 0; + } + else { + return 1; + } + } + } + + + if (WScript.Arguments.length == 0) { + // install/uninstall + WScript.Quit(install()); + + + +Reschke Informational [Page 12] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + } + else { + // try to invoke Webfolder + + var inp = new ActiveXObject("MSXML2.DOMDocument"); + var furi = encodeURI(WScript.Arguments(0)); + if (! inp.load(furi)) { + WScript.Echo("Can't read from '" + + WScript.Arguments(0) + "'!"); + WScript.Quit(2); + } + + inp.setProperty("SelectionLanguage", "XPath"); + inp.setProperty("SelectionNamespaces", + "xmlns:m='http://purl.org/NET/webdav/mount'"); + + var n1 = inp.selectSingleNode("/m:mount/m:url"); + var n2 = inp.selectSingleNode("/m:mount/m:open"); + + if (n1 == null) { + WScript.Echo(" element missing."); + WScript.Quit(2); + } + + var ie = new ActiveXObject("InternetExplorer.Application"); + + ie.Navigate("about:blank"); + var doc = ie.Document; + + var folder = doc.createElement("span"); + folder.addBehavior("#default#httpFolder"); + + var result = folder.navigate(n1.text + + (n2 == null ? "" : n2.text)); + + // close the window again when there was no element + if (n2 == null) ie.Quit(); + + if (result != "OK") { + if (result == "PROTOCOL_NOT_SUPPORTED") { + WScript.Echo("This site doesn't seem to support WebDAV."); + WScript.Quit(1); + } + else { + WScript.Echo("Unexpected status: " + result); + WScript.Quit(2); + } + } + + + +Reschke Informational [Page 13] + +RFC 4709 Mounting WebDAV Servers October 2006 + + + } + +B.2. Xythos + + The "Xythos Drive" WebDAV client for WebDAV supports this + specification starting with version 4.4. + +Author's Address + + Julian F. Reschke + greenbytes GmbH + Hafenweg 16 + Muenster, NW 48155 + Germany + + Phone: +49 251 2807760 + Fax: +49 251 2807761 + EMail: julian.reschke@greenbytes.de + URI: http://greenbytes.de/tech/webdav/ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Reschke Informational [Page 14] + +RFC 4709 Mounting WebDAV Servers October 2006 + + +Full Copyright Statement + + Copyright (C) The Internet Society (2006). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET + ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, + INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE + INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + +Acknowledgement + + Funding for the RFC Editor function is provided by the IETF + Administrative Support Activity (IASA). + + + + + + + +Reschke Informational [Page 15] + -- cgit v1.2.3