Network Working Group C. Newman Internet-Draft Sun Microsystems Expires: May 26, 2003 November 25, 2002 ACAP Personal Addressbook Dataset Class draft-ietf-acap-abook-03.txt 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 May 26, 2003. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract Internet Message Access Protocol (IMAP) allows nomadic users to access their mail store from any client, but it does not support storage of personal addressbooks. Application Configuration Access Protocol (ACAP) provides a mechanism for storage of personal addressbooks. While ACAP permits the definition of vendor specific solutions to this problem, having a documented addressbook dataset class permits clients from different vendors to interoperably share the same personal addressbooks. This specification defines an ACAP dataset class for personal addressbooks. Newman Expires May 26, 2003 [Page 1] Internet-Draft ACAP Addressbook Dataset Class November 2002 Table of Contents 1. Conventions Used in this Document . . . . . . . . . . . . . . 3 2. Design Issues . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1 Reason for Publication . . . . . . . . . . . . . . . . . . . . 3 3. ACAP Personal Addressbooks . . . . . . . . . . . . . . . . . . 3 3.1 ACAP Addressbook Dataset Class . . . . . . . . . . . . . . . . 3 3.2 ACAP Addressbook Capability . . . . . . . . . . . . . . . . . 4 3.3 ACAP Addressbook Hierarchy . . . . . . . . . . . . . . . . . . 4 4. Recommended ACAP Attributes . . . . . . . . . . . . . . . . . 4 4.1 Basic Attributes . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Naming Attributes . . . . . . . . . . . . . . . . . . . . . . 5 4.3 Reference Attribute . . . . . . . . . . . . . . . . . . . . . 7 4.4 Computer Communication Attributes . . . . . . . . . . . . . . 7 4.5 Telephone Number Attributes . . . . . . . . . . . . . . . . . 10 4.6 Postal Address Attributes . . . . . . . . . . . . . . . . . . 12 4.7 Commentary Attributes . . . . . . . . . . . . . . . . . . . . 12 4.8 Locational Attributes . . . . . . . . . . . . . . . . . . . . 13 4.9 Public Keys . . . . . . . . . . . . . . . . . . . . . . . . . 14 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6. Mapping vCards to ACAP addressbooks . . . . . . . . . . . . . 16 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 8. Security Considerations . . . . . . . . . . . . . . . . . . . 18 Normative References . . . . . . . . . . . . . . . . . . . . . 19 Informative References . . . . . . . . . . . . . . . . . . . . 19 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 21 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Intellectual Property and Copyright Statements . . . . . . . . 23 Newman Expires May 26, 2003 [Page 2] Internet-Draft ACAP Addressbook Dataset Class November 2002 1. Conventions Used in this Document The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as defined in "Key words for use in RFCs to Indicate Requirement Levels" [2]. The attribute syntax specifications use the Augmented Backus-Naur Form (ABNF) [3] notation including the core rules defined in Appendix A. This also inherits ABNF rules from ACAP [4], SMTP [7], URI [6] and Language Tags [8]. When UTF-8 [5] is referred to in this document, it refers to an encoding of Unicode version 2.0 or later, and not Unicode version 1.1. 2. Design Issues Although this is not a white pages service, in order to provide more consistency, this was designed to match the Common Schema for Internet White Pages [13]. It was also designed to minimize email client complexity, provide a clean model for personal distribution lists and hierarchical addressbooks and permit storage of vCards [17] for correspondents. Personal addressbooks differ from white pages services because all the attributes and entries are controlled by the user who owns the addressbook rather than a directory administrator. The user or the clients he uses may add new attributes at any time and some of these attributes are not suitable for a white pages service. 2.1 Reason for Publication This document is the result of some hard work in the mid to late 1990s. Given the current direction of the market for which this protocol was designed, it appears relatively unlikely the specific combination of ACAP [4] with this specification will be widely deployed on the Internet. However, the author believes this work will be valuable for future reference by those working on personal address book systems. 3. ACAP Personal Addressbooks 3.1 ACAP Addressbook Dataset Class Datasets whose names begin with "/addressbook" are assumed to contain addressbook entries as defined in this specification. Newman Expires May 26, 2003 [Page 3] Internet-Draft ACAP Addressbook Dataset Class November 2002 3.2 ACAP Addressbook Capability The "addressbook.Expand.Address" and "addressbook.Expand.Complete" attributes require active client or server support. The attribute "capability.addressbook.expand" in the "/capability/~/addressbook" entry is non-NIL if they are supported. 3.3 ACAP Addressbook Hierarchy Hierarchical addressbooks SHOULD be represented using ACAP hierarchy. Any entry in an addressbook can also be a hierarchy node by setting the "subdataset" attribute. This structure is used to represent both sub-addressbooks and mailing lists. 4. Recommended ACAP Attributes The following attributes MAY be used in an ACAP addressbook entry. An addressbook entry MUST have an "entry" attribute, and one or more of "addressbook.Alias", "addressbook.CommonName" and "addressbook.Email" attributes. The purpose of this rule is to make it possible to easily select an attribute which can be displayed to a user. An addressbook entry MUST have at most one of the attributes "addressbook.List", "addressbook.Reference", and "addressbook.Email". The purpose of this rule is to force each entry to be either a regular addressbook entry with an Email address, a pointer to another addressbook entry, or a distribution list. In order to resolve ambiguities, if there is an "addressbook.List" attribute, both "addressbook.Email" and "addressbook.Reference" attributes MUST be ignored. If there is no "addressbook.List" attribute but there is an "addressbook.Email" attribute, then the "addressbook.Reference" attribute MUST be ignored. Beyond these rules, clients MAY choose any subset of these attributes as well as using registered private attributes. Clients are encouraged to provide a way to view all textual attributes in an entry regardless of whether the client knows the special semantics associated with them. The ABNF defines the content of the attribute values prior to their encoding as an ACAP string. Clients MUST conform to the syntax when generating these attributes, but MUST NOT assume that the attribute values will conform to this syntax on access. Servers MUST NOT enforce the syntax. Unless otherwise stated, all attributes in this specification are single-valued and textual. Newman Expires May 26, 2003 [Page 4] Internet-Draft ACAP Addressbook Dataset Class November 2002 4.1 Basic Attributes These attributes are defined in ACAP [4] and have meaning in all dataset classes. This section describes how they are used in an addressbook dataset. entry The "entry" attribute is a unique string used to refer to an addressbook entry within an addressbook dataset. It is client defined and may not be suitable for display to users. subdataset The "subdataset" attribute is used both for addressbook hierarchy and for addressbook distribution lists. It indicates there is another addressbook dataset underneath this entry. If there is also an "addressbook.List" attribute, then this entry is an email distribution list and the subdataset contains the members of that list. If "subdataset" exists, then any "addressbook.Email" or "addressbook.Reference" attributes SHOULD be ignored. 4.2 Naming Attributes These attributes contain information about the name of the person or entity to which the entry refers. addressbook.CommonName The "addressbook.CommonName" attribute holds the full common name of the person or entity to which the addressbook entry refers. If a person or entity has multiple names, they may be stored in the "addressbook.AlternateNames" attribute. abook-common-name = 1*TEXT-UTF8-CHAR addressbook.GivenName The "addressbook.GivenName" attribute holds the given name of the person to which the addressbook entry refers. abook-given-name = 1*TEXT-UTF8-CHAR Newman Expires May 26, 2003 [Page 5] Internet-Draft ACAP Addressbook Dataset Class November 2002 addressbook.Surname The "addressbook.Surname" attribute holds the surname (or family name) of the person to which the addressbook entry refers. abook-surname = 1*TEXT-UTF8-CHAR addressbook.MiddleName This holds the middle name(s) or initial(s) of the person to which the addressbook entry refers. If there are multiple such names or initials, they are separated by a space. abook-middle = 1*TEXT-UTF8-CHAR addressbook.Prefix This holds any prefixes (e.g., "Mr.", "Mrs.") for the person to which the addressbook entry refers. abook-prefix = 1*TEXT-UTF8-CHAR addressbook.Suffix This holds any suffixes (e.g., "Jr.", "M.D.") for the person to which the addressbook entry refers. abook-suffix = 1*TEXT-UTF8-CHAR addressbook.AlternateNames This is a multi-value attribute containing a list of alternate names for the entry. Short attributes describing the use of the alternate name may follow the name, separated by a NUL character. NUL = %x00 ; US-ASCII NUL character abook-alt-name = 1*TEXT-UTF8-CHAR *(NUL 1*TEXT-UTF8-CHAR) ; multi-valued addressbook.Alias A shorthand way to refer to this entry (e.g., a nickname). Clients are discouraged from storing characters which fall into the class of "white-space" or "specials" as defined in Internet Message Format [21] with the exception of period ("."). The alias is typically used by clients as a way for users to quickly refer to a particular addressbook entry via a type-in field. For this Newman Expires May 26, 2003 [Page 6] Internet-Draft ACAP Addressbook Dataset Class November 2002 to work best, clients are encouraged to avoid using the same alias in multiple entries within a dataset. abook-alias = 1*<"." or any TEXT-UTF8-CHAR except white-space or specials as defined in RFC 2822> 4.3 Reference Attribute addressbook.Reference This addressbook entry is a reference to another ACAP addressbook entry, or an LDAP white pages entry. The reference is in the form of a relative or absolute URI [6]. Clients SHOULD support this attribute for the local ACAP server and MAY support it for other ACAP or LDAP servers. abook-reference = relativeURI / absoluteURI ; as defined in RFC 2396 4.4 Computer Communication Attributes These attributes are related to computer communication. The format for email addresses MUST be canonicalized so it is suitable for use over SMTP [7]. Linear-white-space and obsolete address formats from Internet Message Format [21] are not permitted in a canon-addr-spec. The canonical format for a "mailbox" eliminates folding and obsolete formats. canon-addr-spec = Local-part "@" Domain ; Terminals defined in RFC 2821 canon-disp-name = (Atom / Quoted-string) *(SP (Atom / Quoted-string)) ; Terminals defined in RFC 2821 canon-mailbox = canon-disp-name SP "<" canon-addr-spec ">" canon-address = canon-mailbox / canon-addr-spec addressbook.CommonName.MIME This contains the CommonName encoded as a US-ASCII string according to the rules in MIME Headers [1]. This is set when a personal addressbook entry is created from an Internet Mail Address [21] which uses MIME Header encoding for the common name Newman Expires May 26, 2003 [Page 7] Internet-Draft ACAP Addressbook Dataset Class November 2002 portion of the address. This is the preferred attribute to use for the phrase portion of the Internet Mail Address as it preserves the sender's preferred character set. Otherwise, the phrase is constructed from the "addressbook.CommonName" field with all non US-ASCII characters encoded according to MIME headers using UTF-8. This attribute SHOULD be NIL if the CommonName is made up of only US-ASCII characters or the sender's preferred character set is UTF-8. abook-mime-hdr = canon-disp-name addressbook.Email The primary email address for contacting the person or entity to which this entry refers. abook-email = canon-addr-spec addressbook.EmailOther This is a multi-valued attribute containing alternate email addresses for the user. The purpose of a particular email address may be included in short tokens after the address, separated by a NUL. abook-emailother = canon-addr-spec *(NUL 1*TEXT-UTF8-CHAR) addressbook.List If both this attribute and the "subdataset" attribute exist then this entry is an email distribution list. The entries in the subdataset are the members of the list. When this attribute exists, then any "addressbook.Email" or "addressbook.Reference" attributes SHOULD be ignored. abook-list = "1" addressbook.Expand.Address This is an operational attribute which is present if the ACAP server announces the ADDRESSBOOK capability. Its value is computed by the ACAP server. The result is a CRLF-separated list of all the values from the addressbook.Email attributes of this entry, any entry referred to by "addressbook.Reference" on the local server, and any entries contained in the "subdataset" on this server. This expansion is recursive. abook-expand-addr = canon-addr-spec *(CRLF canon-addr-spec) Newman Expires May 26, 2003 [Page 8] Internet-Draft ACAP Addressbook Dataset Class November 2002 addressbook.Expand.Complete This is an operational attribute which is present if the ACAP server announces the ADDRESSBOOK capability. Its value is computed by the ACAP server. The result is a CRLF-separated list of all the Internet Mail Addresses as computed from the addressbook.Email, addressbook.CommonName, and addressbook.CommonName.MIME attributes. The entry itself, any entry referred to by "addressbook.Reference" on the local server, and any entries contained in the "subdataset" on the local server are expanded. This expansion is recursive. abook-expand-compl = canon-address *(CRLF canon-address) addressbook.List.Subscribe This entry contains a URI [6] for the subscription address of the mailing list to which this entry refers (mailto URLs [15] are preferred). Any unknown "?" portions of a mailto URL in this context are ignored to permit future extension. The addressbook.List attributes are based on the List-* headers defined in The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields [16]. abook-subscribe = absoluteURI addressbook.List.Unsubscribe This entry contains a URI [6] for the un-subscription address of the mailing list to which this entry refers (mailto URLs are preferred). Any unknown "?" portions of a mailto URL in this context are ignored to permit future extension. abook-unsubscribe = absoluteURI addressbook.List.Help This entry contains a URI [6] for help information about the mailing list to which this entry refers. Any unknown "?" portions of a mailto URL in this context are ignored to permit future extension. abook-listhelp = absoluteURI Newman Expires May 26, 2003 [Page 9] Internet-Draft ACAP Addressbook Dataset Class November 2002 addressbook.Subscribed If this attribute is non-NIL, then the entry refers to a mailing list address to which the addressbook's owner is currently subscribed. abook-subscribed = "1" addressbook.HomePage This contains the URI [6] to the primary home page describing the person or entity to which the addressbook entry refers. abook-home-page = absoluteURI addressbook.HomePageOther This is a multi-valued attribute containing alternate home page URLs for the person or entity to which the addressbook entry refers. abook-home-page = absoluteURI 4.5 Telephone Number Attributes Fully qualified international form is preferred for telephone numbers +1 555 555 1234 ext 54 but as these are likely to be human-entered any form is permitted. A telephone number may be qualified with attributes describing its uses. These attributes are separated from the number by a NUL character. The following attributes are initially defined: home This is a residence phone number work This is an office phone number msg This number has voice messaging support cell This is a cellular telephone number voice This number is a voice number fax This number has fax support modem This number has modem support pager This is a pager number Newman Expires May 26, 2003 [Page 10] Internet-Draft ACAP Addressbook Dataset Class November 2002 Thus a number such as: +1 555 555 1234 ext 54officevoicemsg Indicates an office voice phone with voice messaging. The intention is to keep the telephone attributes aligned with the vCARD [VCARD] specification. The formal syntax is as follows: abook-phone = 1*TEXT-UTF8-CHAR *(NUL abook-use-attribute) abook-use-attribute = "home" / "work" / "msg" / "cell" / "voice" / "fax" / "modem" / "pager" / abook-use-ext abook-use-ext = 1*ATOM-CHAR ; see ACAP base spec for ATOM-CHAR ; reserved for future extension addressbook.Telephone This is the primary telephone number for the person referred to by the entry. abook-telephone = abook-phone addressbook.TelephoneOther This multi-valued attribute may hold additional telephone numbers. abook-phone-other = abook-phone Newman Expires May 26, 2003 [Page 11] Internet-Draft ACAP Addressbook Dataset Class November 2002 4.6 Postal Address Attributes Postal addresses should be in the same format that they appear on an envelope, preferably fully qualified. The multiple lines are CRLF separated within the attribute. addressbook.Postal This contains the preferred postal address for the person or entity referred to by the entry. Attributes may be added to the end of the address with a NUL separator. The attributes "home" and "work" are initially defined to refer to home and work addresses. abook-postal = 1*TEXT-UTF8-CHAR *(CRLF *TEXT-UTF8-CHAR) *(NUL abook-postal-attr) abook-postal-attr = "home" / "work" / abook-use-ext addressbook.PostalOther This is a multi-valued attribute which contains alternate postal addresses. This uses the same syntax as the Postal attribute. abook-postalother = abook-postal 4.7 Commentary Attributes These are free-form text attributes used to store commentary about the entry. addressbook.Comment This is a free-form text field where the owner of the addressbook may put comments about the person or entity referred to by the entry. abook-comment = 1*UTF8-CHAR addressbook.Description This is a free-form comment field for a self-description of the person or entity referred to by the entry. It is primarily used when an entry is imported from a remote directory. abook-description = 1*UTF8-CHAR Newman Expires May 26, 2003 [Page 12] Internet-Draft ACAP Addressbook Dataset Class November 2002 4.8 Locational Attributes These contain information about the location of the person or entity referred to by this entry. addressbook.Organization If the person or entity to which the entry refers is a member of an organization, this attribute contains the name of that organization. abook-organization = 1*TEXT-UTF8-CHAR addressbook.Title This is the title of the person referred to by the entry. abook-title = 1*TEXT-UTF8-CHAR addressbook.Locality This is the name of the locality where the person or entity is normally located. abook-locality = 1*TEXT-UTF8-CHAR addressbook.Country This is the country code [23] where the person or entity is normally located. abook-country = 2*3ALPHA addressbook.Language This is the language code [8] for the language which the person or entity prefers to speak. abook-language = Language-Tag ; as defined in RFC 3066 addressbook.LanguageOther This is a multi-valued attribute containing language tags for alternate languages which the person or entity can speak. abook-languageother = Language-Tag ; as defined in RFC 3066 Newman Expires May 26, 2003 [Page 13] Internet-Draft ACAP Addressbook Dataset Class November 2002 4.9 Public Keys The PGP [18] or S/MIME [20] public key for a correspondent MAY be included in the addressbook entry. addressbook.PGP.bin This holds the binary form of the primary signature PGP public key for the person or entity referred to by the addressbook entry. The format is as documented in [18]. Clients MUST check the version number field to permit future versions. abook-pgp = *OCTET ; as defined in RFC 2440 addressbook.PGPOther.bin This is a multi-valued attribute containing alternate PGP public keys for this entry. It is assumed that the purpose for the alternate keys is encoded in the key format itself. abook-pgp-other = *OCTET ; as defined in RFC 2440 addressbook.SMIMEv3.bin This holds the binary form of the primary signature S/MIME public key for the person or entity referred to by the addressbook entry. abook-smime3 = *OCTET ; as defined in RFC 2633 addressbook.SMIMEv3Other.bin This is a multi-valued attribute containing alternate S/MIME public keys for the person or entity referred to by the addressbook entry. It is assumed that the purpose for the alternate keys is encoded in the key format itself. abook-smime3-other = *OCTET ; as defined in RFC 2633 Newman Expires May 26, 2003 [Page 14] Internet-Draft ACAP Addressbook Dataset Class November 2002 5. Examples Some sample entries from addressbook /addressbook/user/hubert: attribute name value -------------- ----- entry ABC123 addressbook.CommonName Patrik Faltstrom addressbook.GivenName Patrik addressbook.Surname Faltstrom addressbook.Email paf@example.com addressbook.CommonName.MIME =?ISO-8859-1?Q?Patrik_F=E4ltstr=F6m?= addressbook.Expand.Address paf@example.com addressbook.Expand.Complete =?ISO-8859-1?Q?Patrik_F=E4ltstr=F6m?= entry ABC567 addressbook.CommonName Terry Gray addressbook.GivenName Terry addressbook.Surname Gray addressbook.Alias teg addressbook.Email gray@example.com addressbook.Expand.Address gray@example.com addressbook.Expand.Complete Terry Gray entry defghi subdataset . addressbook.List 1 addressbook.CommonName List of Two addressbook.CommonName.MIME List of Two addressbook.Expand.Address paf@example.com gray@example.com fred@bedrock.example.com addressbook.Expand.Complete =?ISO-8859-1?Q?Patrik_F=E4ltstr=F6m?= Terry Gray Fred Flintstone Newman Expires May 26, 2003 [Page 15] Internet-Draft ACAP Addressbook Dataset Class November 2002 In dataset /addressbook/user/hubert/defghi: entry xyz1 addressbook.Reference ../ABC123 addressbook.Expand.Address paf@example.com addressbook.Expand.Complete =?ISO-8859-1?Q?Patrik_F=E4ltstr=F6m?= entry xyz2 addressbook.Reference ../ABC567 addressbook.Expand.Address gray@example.com addressbook.Expand.Complete Terry Gray entry z2t addressbook.CommonName Fred Flintstone addressbook.GivenName Fred addressbook.Surname Flintstone addressbook.Email fred@bedrock.example.com addressbook.CommonName.MIME Fred Flintstone addressbook.Expand.Address fred@bedrock.example.com addressbook.Expand.Complete Fred Flintstone 6. Mapping vCards to ACAP addressbooks An ACAP addressbook can store vCards [17]. It provides access to business cards of your contacts from any machine you use regularly, complete with the ability to annotate the contact information. The following table describes the mapping. A multi-valued vCard "type" is mapped to either a multi-valued ACAP attribute or the "preferred" instance is mapped to a single value ACAP attribute and other instances are mapped to a separate multi-valued ACAP attribute. A vCard "type" which may be either a URI or a binary value is mapped to one of two ACAP attributes named appropriately. vCard "TYPE=" parameters from vCard types are mapped to ACAP attribute value syntax in a similar fashion to the addressbook.Telephone attribute. ACAP attributes not defined above follow the same syntax and semantics as an untyped vCard attribute. vCard "type" ACAP personal addressbook attribute(s) ------------ -------------------------------------- FN addressbook.CommonName N addressbook.Surname addressbook.GivenName addressbook.MiddleName addressbook.Prefix addressbook.Suffix Newman Expires May 26, 2003 [Page 16] Internet-Draft ACAP Addressbook Dataset Class November 2002 NICKNAME addressbook.AlternateNames *1 PHOTO addressbook.Photo.bin or addressbook.Photo.URI BDAY addressbook.Bday ADR addressbook.Adr *2 LABEL addressbook.Postal and addressbook.PostalOther TEL addressbook.Telephone and addressbook.TelephoneOther EMAIL addressbook.Email *3 addressbook.EmailOther MAILER addressbook.Mailer TZ addressbook.TZ GEO addressbook.GEO TITLE addressbook.Title ROLE addressbook.Role LOGO addressbook.Logo.bin addressbook.Logo.URI AGENT addressbook.Agent.URI ORG addressbook.Organization CATEGORIES addressbook.Categories (multi-valued) NOTE addressbook.Note PRODID addressbook.vCard.Prodid *4 REV addressbook.vCard.Rev *4 SORT-STRING addressbook.SortString SOUND addressbook.Sound.bin addressbook.Sound.URI UID addressbook.vCard.uid *4 URL addressbook.HomePage VERSION addressbook.vCard.Version *4 CLASS addressbook.vCard.Class *4 KEY addressbook.PGP.bin *5 KEY addressbook.SMIMEv3.bin *5 *1 - space separated single valued attribute *2 - Multi-valued attribute. Each value follows vCard value syntax, with vCard type "TYPE=" parameters mapped in a similar fashion to the addressbook.Telephone attribute. *3 - only for "TYPE=internet". No mapping exists for other types. *4 - only used when mapping from a vCard *5 - map with appropriate "TYPE=" attribute. Newman Expires May 26, 2003 [Page 17] Internet-Draft ACAP Addressbook Dataset Class November 2002 7. IANA Considerations This document constitutes the registration for the "addressbook" dataset class per section 7.3 of ACAP [4]. Dataset class name/attribute prefix: addressbook Purpose: Personal addressbooks (Section 4) Published Specification(s): This specification Person and email address to contact for further information: See the "Author's Address" section near the end of this specification. 8. Security Considerations An ACAP dataset class inherits the security considerations of the ACAP specification [4]. Personal addressbooks have frequently been used as an extremely effective mechanism to distribute email-bourne worms. Recipients often trust active content from frequent correspondents, and the personal addressbook provides a convenient list of such potential recipients. Clients which access personal address books and support active content MUST have a mechanism which prevents active content from accessing the personal addressbook without explicit permission from the end-user. The risks of active content described in MIME Media Types [11] also apply to such clients. Because the use of a personal address book as a worm distribution list is such a serious risk, the password (or other credential) used to access an ACAP server holding personal addressbooks has to be treated with great care. If the ACAP password is stored on persistent media (e.g., the hard disk), it SHOULD be stored in an encrypted keychain which verifies a secure hash of any binary or active content prior to granting access to that password. The MacOS X keychain is an example of such a system. This secure hash validation is particularly important for single-sign-on mechanisms such as the one provided by Kerberos [9]. An application which provides an indirect interface to an ACAP personal address book (e.g. via a scripting language) will inherit these security considerations and has to provide an authorization mechanism for the consumer of that interface. While it is common to share an organizational directory with the Newman Expires May 26, 2003 [Page 18] Internet-Draft ACAP Addressbook Dataset Class November 2002 entire organization, personal addressbooks need to be treated as private information by default. Public exposure of otherwise private comments in an addressbook can have serious consequences (e.g., if an employee uses the alias "idiot" for his boss, that employee might be fired if that addressbook was exposed publicly). Therefore, addressbook user interfaces need to clearly indicate when the ACAP access controls on an addressbook dataset permit access by users other than the owner. If PGP or S/MIME public keys are stored in a remote personal addressbook this creates a situation where an attacker could substitute a different public key for the purpose of impersonating a correspondent. Using an ACAP protocol security layer (such as TLS [19] or SASL [14]) which provides at least integrity protection would defend against this attack. If the public key includes an appropriate trust chain and/or signed email address, verifying those items can also mitigate this attack. Normative References [1] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [3] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [4] Newman, C. and J. Myers, "ACAP -- Application Configuration Access Protocol", RFC 2244, November 1997. [5] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC 2279, January 1998. [6] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. [7] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, April 2001. [8] Alvestrand, H., "Tags for the Identification of Languages", BCP 47, RFC 3066, January 2001. Informative References [9] Kohl, J. and B. Neuman, "The Kerberos Network Authentication Newman Expires May 26, 2003 [Page 19] Internet-Draft ACAP Addressbook Dataset Class November 2002 Service (V5)", RFC 1510, September 1993. [10] Hovey, R. and S. Bradner, "The Organizations Involved in the IETF Standards Process", BCP 11, RFC 2028, October 1996. [11] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [12] Crispin, M., "Internet Message Access Protocol - Version 4rev1", RFC 2060, December 1996. [13] Genovese, T. and B. Jennings, "A Common Schema for the Internet White Pages Service", RFC 2218, October 1997. [14] Myers, J., "Simple Authentication and Security Layer (SASL)", RFC 2222, October 1997. [15] Hoffman, P., Masinter, L. and J. Zawinski, "The mailto URL scheme", RFC 2368, July 1998. [16] Neufeld, G. and J. Baer, "The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields", RFC 2369, July 1998. [17] Dawson, F. and T. Howes, "vCard MIME Directory Profile", RFC 2426, September 1998. [18] Callas, J., Donnerhacke, L., Finney, H. and R. Thayer, "OpenPGP Message Format", RFC 2440, November 1998. [19] Newman, C., "Using TLS with IMAP, POP3 and ACAP", RFC 2595, June 1999. [20] Ramsdell, B., "S/MIME Version 3 Message Specification", RFC 2633, June 1999. [21] Resnick, P., "Internet Message Format", RFC 2822, April 2001. [22] Elkins, M., Del Torto, D., Levien, R. and T. Roessler, "MIME Security with OpenPGP", RFC 3156, August 2001. [23] International Organization for Standardization, "Codes for the representation of names of countries, 3rd edition", ISO Standard 3166, August 1988. Newman Expires May 26, 2003 [Page 20] Internet-Draft ACAP Addressbook Dataset Class November 2002 Author's Address Chris Newman Sun Microsystems 1050 Lakes Drive West Covina, CA 91790 US EMail: chris.newman@sun.com Newman Expires May 26, 2003 [Page 21] Internet-Draft ACAP Addressbook Dataset Class November 2002 Index A addressbook.Alias 6 addressbook.AlternateNames 6 addressbook.Comment 12 addressbook.CommonName 5 addressbook.CommonName.MIME 7 addressbook.Country 13 addressbook.Description 12 addressbook.Email 8 addressbook.EmailOther 8 addressbook.Expand.Address 8 addressbook.Expand.Complete 9 addressbook.GivenName 5 addressbook.HomePage 10 addressbook.HomePageOther 10 addressbook.Language 13 addressbook.LanguageOther 13 addressbook.List 8 addressbook.List.Help 9 addressbook.List.Subscribe 9 addressbook.List.Unsubscribe 9 addressbook.Locality 13 addressbook.MiddleName 6 addressbook.Organization 13 addressbook.PGP.bin 14 addressbook.PGPOther.bin 14 addressbook.Postal 12 addressbook.PostalOther 12 addressbook.Prefix 6 addressbook.Reference 7 addressbook.SMIMEv3.bin 14 addressbook.SMIMEv3Other.bin 14 addressbook.Subscribed 9 addressbook.Suffix 6 addressbook.Surname 5 addressbook.Telephone 11 addressbook.TelephoneOther 11 addressbook.Title 13 E entry 5 S subdataset 5 Newman Expires May 26, 2003 [Page 22] Internet-Draft ACAP Addressbook Dataset Class November 2002 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. 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