LEMONADE Working Group S. Maes Internet-Draft Oracle Expires: August 2, 2006 A. Melnikov Isode D. Cridland Details To Be Added January 29, 2006 LEMONADE profile bis draft-ietf-lemonade-profile-bis-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 August 2, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document describes LEMONADE profile bis. It contains pointers or mention to all the features that are normatively part of LEMONADE profile bis. It is based on a combination of the content of LEMONADE profile [4] Maes, et al. Expires August 2, 2006 [Page 1] Internet-Draft LEMONADE profile bis January 2006 and the OMA MEM realization internet draft [21], initially considered for internet draft publication as information or standard track by LEMONADE. It reflects the agreed content for LEMONADE profile bis after the Beijing LEMONADE Intermediate face to face meeting. 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 RFC 2119 [1]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. LEMONADE Profile . . . . . . . . . . . . . . . . . . . . . . . 4 3. OMA MEM Requirement document . . . . . . . . . . . . . . . . . 5 4. OMA MEM Architecture . . . . . . . . . . . . . . . . . . . . . 6 5. OMA MEM Deployment Issues . . . . . . . . . . . . . . . . . . 7 6. OMA MEM proxy . . . . . . . . . . . . . . . . . . . . . . . . 8 7. IETF LEMONADE Architecture . . . . . . . . . . . . . . . . . . 9 8. LEMONADE profile bis logical architecture . . . . . . . . . . 11 8.1. Relationship between the OMA MEM and LEMONADE logical architectures . . . . . . . . . . . . . . . . . . . . . . 11 8.2. LEMONADE realization of OMA MEM with non-LEMONADE compliant servers . . . . . . . . . . . . . . . . . . . . 12 8.2.1. LEMONADE realization of OMA MEM with non-LEMONADE enhanced IMAP servers . . . . . . . . . . . . . . . . 12 8.2.2. LEMONADE realization of OMA MEM with non-IMAP servers . . . . . . . . . . . . . . . . . . . . . . . 13 9. Filters and server to client notifications and LEMONADE . . . 15 10. LEMONADE Profile bis features . . . . . . . . . . . . . . . . 17 11. Security considerations . . . . . . . . . . . . . . . . . . . 19 12. IANA considerations . . . . . . . . . . . . . . . . . . . . . 20 13. Future work . . . . . . . . . . . . . . . . . . . . . . . . . 21 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 22 15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 24 Intellectual Property and Copyright Statements . . . . . . . . . . 25 Maes, et al. Expires August 2, 2006 [Page 2] Internet-Draft LEMONADE profile bis January 2006 1. Introduction This document describes LEMONADE profile bis. It contains pointers or mention to all the features that are normatively part of LEMONADE profile bis. It is based on LEMONADE profile [4] with extensions to provide the support to a realization of OMA mobile email enabler (MEM) using Internet Mail protocols defined by the IETF. Many of these protocols have been enhanced by the LEMONADE work group for use in the mobile environment and are summarized in the LEMONADE profile [4]. This document also supports the requirements captured in OMA MEM Requirement document [3] and mechanisms of the OMA MEM Architecture [2], following the LEMONADE point of view described in the OMA MEM realization internet draft [21]. This document contains the current view of the work. It refers to stable specifications and work in progress. As the work progress, it is expected that this document will evolve and be updated accordingly. Also, it is to be noted that this document solely describes normatively the LEMONADE profile bis. It discusses LEMONADE understanding of the work in progress at OMA MEM ([3] and [2] but does not provide a normative reading of these documents. Readers MUST refer to the open mobiel alliance web site for normative references on the Mobile Email Enabler (OMA MEM). LEMONADE assumes that the LEMONADE profile bis can be used as basis for an OMA technical specification of a realization based on LEMONADE of the OMA MEM enabler. Maes, et al. Expires August 2, 2006 [Page 3] Internet-Draft LEMONADE profile bis January 2006 2. LEMONADE Profile LEMONADE profile bis incorporates normatively the LEMONADE profile [4]. Maes, et al. Expires August 2, 2006 [Page 4] Internet-Draft LEMONADE profile bis January 2006 3. OMA MEM Requirement document The OMA MEM activity has collected a set of use cases and derived requirements for a mobile email enabler (MEM). the resulting work is summarized in OMA MEM Requirement document [3]. Some requirements relates to email protocols, some involve other OMA technologies outside the scope of IETF and some relate to implementations and normative interoperability statements for clients and servers. Maes, et al. Expires August 2, 2006 [Page 5] Internet-Draft LEMONADE profile bis January 2006 4. OMA MEM Architecture The OMA MEM activity has derived a logical architecture from the requirements and use cases described in [3]. The logical architecture, its elements and interfaces and the notations that it uses can be found in [2]. Maes, et al. Expires August 2, 2006 [Page 6] Internet-Draft LEMONADE profile bis January 2006 5. OMA MEM Deployment Issues The OMA MEM Architecture document [2] further identifies deployment models. Certain of these deployment models are not what IETF has conventionally modeled. They require special attention to end-to-end security aspects and may warrant introduction of additional security measures (e.g. object level encryption). Maes, et al. Expires August 2, 2006 [Page 7] Internet-Draft LEMONADE profile bis January 2006 6. OMA MEM proxy The OMA MEM Architecture document [2] identifies OMA MEM server proxies as server components that may be deployed ahead of firewalls to facilitate traversal of firewalls. Both IMAP and SMTP generally are compatible with proxies between the client and the server. Such proxies may disrupt end-to-end encryption, with the transport-level encryption ending at the proxy and re-generating from the proxy to the server. Again this may require additional security measures like object level encryption. Maes, et al. Expires August 2, 2006 [Page 8] Internet-Draft LEMONADE profile bis January 2006 7. IETF LEMONADE Architecture This section gives a brief introduction to the LEMONADE Architecture. The IETF LEMONADE activity has derived a LEMONADE profile [4] with the logical architecture represented in Figure 1, where arrows indicate content flows. ______________ | | _________| Notification | | | Mechanism | | |______________| |Notif. ^ |Protocol | | ___|______ | | | _____ __v__ IMAP | LEMONADE | ESMTP | | | |<----------->| IMAP |<---------------| MTA | | MUA |- | Store | |_____| |_____| \ |__________| \ | \ |URLAUTH \SUBMIT | \ ____v_____ \ | | _____ \ | LEMONADE | ESMTP | | ---->| Submit |--------------->| MTA | | Server | |_____| |__________| Figure 1: LEMONADE logical architecture The LEMONADE profile bis assumes: o IMAP protocol [5] including LEMONADE profile extensions [4] o SUBMIT protocol (SMTP [7], ...) including LEMONADE profile extensions o LEMONADE profile compliant IMAP store connected to MTA (Mail Transfer Agent) via ESMTP [6] o LEMONADE profile compliant Submit server connected to MTA via ESMTP o Lemonade profile ptotocols between message store and submit server (URLAUTH) (see [4]). Maes, et al. Expires August 2, 2006 [Page 9] Internet-Draft LEMONADE profile bis January 2006 o Outband server to client notifications relying on external notification mechanisms (and notification protocols) that may be out of scope of the LEMONADE profile bis. o A LEMONADE aware MUA (Mail User Agent). While use of outband notification is described in the LEMONADE profile bis, support for the underlying notifications mechanisms/protocols is out of scope of the LEMONADE specifications. Further details on the IETF email protocol stack and architecture can be found in [8] Note that in Figure 1 the IMAP server and Submit server are represented connected to MTAs (Mail Transfer Agents) via ESMTP [6]. This is not really essential. It could as well be X.400 so long as the message in the store is in the internet form. OMA MEM identifies other functionalities. These are considered as out of scope of the LEMONADE work and will need to be specified by OMA MEM. Maes, et al. Expires August 2, 2006 [Page 10] Internet-Draft LEMONADE profile bis January 2006 8. LEMONADE profile bis logical architecture This section details the LEMONADE profile bis logical architecture. Thsi architecture is also expected to support the OMA MEM logical Architecture. 8.1. Relationship between the OMA MEM and LEMONADE logical architectures Figure 2 illustrates the mapping of the IETF LEMONADE logical architecture on the OMA MEM logical architecture. _____________________ | Other_Mob. Enablers | | |--------------| | _________| Notification | | | | | Mechanism | | | | |______________| | |Notif. |____________^________| |Protocol ______|__________ ME-4 | | ___|_ME-3_ | ___|____ | | | | _____ | __v__ | IMAP | | LEMONADE | | ESMTP | | || |<----------->| IMAP |<-----------| MTA | || MUA || ME-2a | | Store | | |_____| ||_____||\ME-1 | |__________| | | MEM | \ | | | | Client| \ | |URLAUTH | |_______| \SUBMIT | | \ | ____v_____ | \ | | | | _____ \ | | LEMONADE | | ESMTP | | ---->| Submit |----------->| MTA | ME-2b | | Server | | |_____| | |__________| | |MEM Email | |Server Server| |_________________| ^ |ME-5 | Figure 2: Mapping of LEMONADE profile bis logical architecture onto the OMA MEM logical architecture. As described in Section 7, the LEMONADE profile bis assumes LEMONADE profile bis compliant IMAP stores and Submit servers. Because the Maes, et al. Expires August 2, 2006 [Page 11] Internet-Draft LEMONADE profile bis January 2006 LEMONADE profile bis extends the IMAP store and the submit server, the mobile enablement of email provided by the LEMONADE profile bis is directly provided in these server. Mapped to OMA MEM logical architecture, for the case considered and specified by the LEMONADE profile bis, the MEM server and email server logically combined. They are however split into distinct LEMONADE message store and LEMONADE submit server. The OMA MEM interfaces ME-2 ([2]) consists of two interfaces ME-2a and ME-2b associated respectively to IMAP extended according to the LEMONADE profile bis and SUBMIT extended according to the LEMONADE profile bis. The MUA is part of the MEM client. External notifications mechanism can be part of the other OMA enabler specified by OMA (or other activities). 8.2. LEMONADE realization of OMA MEM with non-LEMONADE compliant servers The OMA MEM activity is not limited to enabling Lemonade compliant servers. It explicitly identifies the need to support other backends. 8.2.1. LEMONADE realization of OMA MEM with non-LEMONADE enhanced IMAP servers Figure 3 illustrates the case of IMAP servers that are not (yet) LEMONADE compliant / enhanced with LEMONADE. In such case, the I2 interface between the MEM server components and the IMAP store and submit server are IMAP and SUBMIT. Maes, et al. Expires August 2, 2006 [Page 12] Internet-Draft LEMONADE profile bis January 2006 ______________ | | _________| Notification | | | Mechanism | | |______________| |Notif. ^ |Protocol | | ___|______ _____________ | | LEMONADE | | | _____ __v__ IMAP | MEM | IMAP |NON-LEMONADE | ESMTP | | | |<--------->|Enabler |<------>|IMAP |<----->| MTA | | MUA |\ ME-2a | Server | |Store | |_____| |_____| \ |__________| |_____________| \ | \ |URLAUTH \SUBMIT | \ ____v_____ _____________ \ | | | | _____ \ | LEMONADE | SUBMIT |NON-LEMONADE | ESMTP | | -->| MEM | |Submit | | | | Enabler |------->|Server |------>| MTA | ME-2b | Server | | | |_____| |__________| |_____________| Figure 3: Architecture to support non-LEMONADE enhanced IMAP servers with a LEMONADE realization of OMA MEM enabler. In Figure 3, the server may be a separate proxy. 8.2.2. LEMONADE realization of OMA MEM with non-IMAP servers Figure 4 illustrates the cases where the message store and submit servers are not IMAP store or submit servers. They may be POP3 servers or other proprietary message stores. Maes, et al. Expires August 2, 2006 [Page 13] Internet-Draft LEMONADE profile bis January 2006 ______________ | | _________| Notification | | | Mechanism | | |______________| |Notif. ^ |Protocol | | ___|______ _____________ | | LEMONADE | | | _____ __v__ IMAP | MEM | I2 |Proprietary | ESMTP | | | |<--------->|Enabler |<------>|Message |<----->| MTA | | MUA |\ ME-2a | Server | |Store | |_____| |_____| \ |__________| |_____________| \ | \ |URLAUTH \SUBMIT | \ ____v_____ _____________ \ | | | | _____ \ | LEMONADE | I2 |Proprietary | ESMTP | | -->| MEM | |Submit | | | | Enabler |------->|Server |------>| MTA | ME-2b | Server | | | |_____| |__________| |_____________| Figure 4: Architecture to support non-IMAP servers with a LEMONADE realization of OMA MEM enabler. I2 designates proprietary adapters to the backends. They may invoved functions performed in the message stores or submit server as well as in the MEM enabler server. In Figure 4, the server may be a separate proxy. Maes, et al. Expires August 2, 2006 [Page 14] Internet-Draft LEMONADE profile bis January 2006 9. Filters and server to client notifications and LEMONADE OMA MEM RD [3] and AD [2] emphasize the need to provide mechanisms for server to client notifications of email events and filtering. Figure 5 illustrates how notification and filterings are introduced in LEMONADE profile bis. ______________ | | _________| Notification | | | Mechanism | | |______________| |Notif. ^ |Protocol -------\ _|_ | ______| ___\>|NF|____ | | | ---- | _____ __v__| IMAP |__ LEMONADE |___ ESMTP __| | | |<-------->|VF| IMAP |DF |<--------|AF| MTA | | MUA |\ ME-2a |-- Store |-^- --|_____| |_____| \ |_____________| | \_\_______________|_______| \ |URLAUTH \SUBMIT | \ ____v_____ \ | | _____ \ | LEMONADE | ESMTP | | ---->| Submit |--------------->| MTA | ME-2b | Server | |_____| |__________| Figure 5: Filtering mechanism defined in LEMONADE architecture In Figure 5, four categories of filters are defined: o AF: Administrative Filters - Set up by email service provider. AF are typically not configured by the user and set to apply policies content filtering, virus protection, spam filtering etc... o DF: Deposit Filters - Filters that are executed on deposit of new emails. They can be defined as SIEVE filters [9]. They can include vacation notices. o VF: View Filters - Filters that define which emails are visible to the MUA. View filters can be defined as virtual folders [10] as described in [10] and [23]. Maes, et al. Expires August 2, 2006 [Page 15] Internet-Draft LEMONADE profile bis January 2006 o NF: Notification Filters - Filters that define for what email server event an outband notification is sent to the client. The filters are manageable from the MUA: o NF and DF: via SIEVE management protocol o VF: via virtual folder mechanisms as discussed in [10] and [23] Maes, et al. Expires August 2, 2006 [Page 16] Internet-Draft LEMONADE profile bis January 2006 10. LEMONADE Profile bis features The LEMONADE Profile bis provides normative support for the technical features identified within scope of IETF LEMONADE work in the OMA MEM realization internet draft [21]. The following is a list of features that will be normatively described: o LEMONADE profile [4] features, evolved to include capabilities to edit on MUA and send differences to server even for address fields.. o Notifications (server to client) as discussed in [23]. o Filters as discussed in [23], [10], [9] and [22]. Events that can be bound to notifications are described in [13]. Filter remote management are discussed in [23], [10] and [26] o Virtual folders as discussed in [10] o Media conversion as discussed in [15]. Streamed media conversion is still under consideration. o Quick reconnect as discussed in [17] o Compression as discussed in [24] o Intermediaries as discussed in [20] to become a best practice document (draft-ietf-lemonade-deployments). It is also addressed by informational track draft [18] o Object level encryption and Proxies are still under discussion. We await proposals. An example of object level encryption is Maes, et al. Expires August 2, 2006 [Page 17] Internet-Draft LEMONADE profile bis January 2006 provided in [25] as XENCRYPT. [23] further discusses the use for notification encryption. o Message recall within SUBMIT domain. Maes, et al. Expires August 2, 2006 [Page 18] Internet-Draft LEMONADE profile bis January 2006 11. Security considerations This specification provides no security measures beyond those in the referenced Internet Mail and LEMONADE documents. We note however the security risks associated to: o Outband notifications o Server configuration by client o Client configuration by server o Presence of proxy servers o Presence of servers as intermediaries o In general the deployment models considered by OMA MEM that are not conventional IETF deployment models. o Measures to address the need to traverse firewalls and mobile network intermediaries. Maes, et al. Expires August 2, 2006 [Page 19] Internet-Draft LEMONADE profile bis January 2006 12. IANA considerations No specific IANA considerations have been identified yet that are not covered by the different drafts and RFCs included in the realization described in this document. Maes, et al. Expires August 2, 2006 [Page 20] Internet-Draft LEMONADE profile bis January 2006 13. Future work The different drafts and RFCs referenced in this document must be completed. Some require initial proposals (e.g. object level encryption, proxies, recall and conversion of streamed media). Text will be updated as described in editor's notes Maes, et al. Expires August 2, 2006 [Page 21] Internet-Draft LEMONADE profile bis January 2006 14. Acknowledgements The author acknowledges and appreciates the work and comments of the IETF LEMONADE working group and the OMA MEM working group. This text was partially co-authored with G. Vaudreuil (Lucent) and Eric Burger (Excel) and reviewed in detail by them as well as by Fan Xiaohui (China Mobile - CMCC). 15. References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirements Levels", RFC 2119, BCP 14, March 1997. [2] "Mobile Email Architecture Document", OMA (Work in Progress), http://www.openmobilealliance.org/, October 2005. [3] "Mobile Email RequirementS Document", OMA http:// www.openmobilealliance.org/release_program/docs/RD/ OMA-RD-MobileEmail-V1_0_20051018-C.pdf, Oct 2005. [4] Maes, S. and A. Melnikov, "LEMONADE profile", draft-ietf-lemonade-profile-0x (work in progress). [5] Crispin, M., "IMAP4, Internet Message Access Protocol Version 4 rev1", RFC 3501, March 2003. [6] Klensin, J., "SMTP Service Extensions", RFC 1861, November 1995. [7] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, April 2001. [8] Crocker, D., "Internet Mail Architecture", draft-crocker-email-arch-0x (work in progress). [9] "SIEVE WG", http://www.ietf.org/html.charters/sieve- charter.html. [10] Maes, S. and et Al., "Persistent Search Extensions and Virtual Folder to the IMAP Protocol", draft-maes-lemonade-vfolder-0x, to become draft-ietf-lemonade-vfolder-0x and draft-ietf-lemonade-search-while-0x (work in progress). [11] Maes, S. and et Al., "Server to Client Notifications and Filtering", draft-maes-lemonade-notifications-server-to-client-0x (work in progress). Maes, et al. Expires August 2, 2006 [Page 22] Internet-Draft LEMONADE profile bis January 2006 [12] Leiba, B., "IMAP4 IDLE command", RFC 2177, June 1997. [13] Newman, C., "Internet Message Store Events", draft-newman-lemonade-msgevent-0x (work in progress). [14] "Open Mobile Alliance Email Notification Version 1.0", OMA http://www.openmobilealliance.org/tech/docs/EmailNot/OMA- Push-EMN-V1_0-20020830-C.pdf, August 2002. [15] Maes, S. and et Al., "CONVERT", draft-ietf-lemonade-convert-0x (work in progress). [16] Melnikov, A. and et Al., "IMAP URL Scheme", draft-ietf-lemonade-rfc2192bis-0x (work in progress). [17] Melnikov, A. and et Al., "IMAP4 extension for quick reconnect", draft-ietf-lemonade-reconnect-0x (work in progress). [18] Maes, S. and et Al., "Lemonade HTTP Binding", draft-maes-lemonade-http-binding-0x to target informational RFC (work in progress). [19] Freed, N., "Behavior of and Requirements for Internet Firewalls", RFC 2979, October 2000. [20] Maes, S., "Lemonade and the challenges of Intermediaries", draft-smaes-lemonade-intermediary-challenges-0x (work in progress). [21] Maes, S. and G. Parsons, "Realization of OMA Mobile Email (MEM) Architecture using Internet Mail", draft-ietf-lemonade-oma-mem-realization-0x (work in progress). [22] Leiba, B., "Support for Sieve in Internet Message Access Protocol (IMAP4)", draft-ietf-lemonade-imap-sieve-0x (work in progress). [23] Maes, S., "Lemonade notifications and filters", draft-ietf-lemonade-notifications-0x (work in progress). [24] Maes, S. and R. Cromwell, "LZIP", draft-maes-lemonade-lzip-0x to become draft-ietf-lemonade-compress-0x (work in progress). [25] Maes, S. and et Al., "Push Extensions to the IMAP Protocol (P-IMAP)", draft-maes-lemonade-p-imap-xx (work in progress). [26] Martin, T. and A. melnikov, "A Protocol for Remotely Managing Sieve Scripts", draft-martin-managesieve-0x (work in progress). Maes, et al. Expires August 2, 2006 [Page 23] Internet-Draft LEMONADE profile bis January 2006 Authors' Addresses Stephane H. Maes Oracle MS 4op634, 500 Oracle Parkway Redwood Shores, CA 94539 USA Phone: +1-203-300-7786 Email: stephane.maes@oracle.com Alexey Melnikov Isode 5 Castle Business Village, 36 Station Road Hampton, Middlesex TW12 2BX UK Email: alexey.melnikov@isode.com Dave Cridland Details To Be Added Email: dave@cridland.net Maes, et al. Expires August 2, 2006 [Page 24] Internet-Draft LEMONADE profile bis January 2006 Intellectual Property Statement 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. Disclaimer of Validity 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. 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Maes, et al. Expires August 2, 2006 [Page 25]