Network Working Group M. Richardson Internet-Draft SSW Expires: December 27, 2007 June 25, 2007 An interface between applications and keying systems draft-ietf-btns-abstract-api-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 December 27, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Richardson Expires December 27, 2007 [Page 1] Internet-Draft btns-abstract-api June 2007 Abstract The "BTNS" (Better Than Nothing Security) protocols specifies how to use IKEv1 and IKEv2 to do unauthenticated IPsec. This document explains in the abstract (no language bindings are provided) how an application may learn that BTNS IPsec has been applied to a conversation, such that the application can plan to do it's own authentication using a channel binding. In addition, applications can use this API (Application Programming Interface) to request BTNS treatment of the applications' connections. Table of Contents 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Objects involved . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Scope of Protection Token . . . . . . . . . . . . . . . . . 5 3.2. Scope of Identity Token . . . . . . . . . . . . . . . . . . 5 3.3. Validity period of Protection Token . . . . . . . . . . . . 5 3.4. Validity period of Identity Token . . . . . . . . . . . . . 6 4. Namespace . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. pToken discovery . . . . . . . . . . . . . . . . . . . . . . 8 6. Properties of pToken objects . . . . . . . . . . . . . . . . 9 7. Properties of iToken objects . . . . . . . . . . . . . . . . 10 8. Accessor Functions . . . . . . . . . . . . . . . . . . . . . 12 9. Security Considerations . . . . . . . . . . . . . . . . . . 13 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 14 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 15 12. TRACKING . . . . . . . . . . . . . . . . . . . . . . . . . . 16 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 17 13.1. Normative references . . . . . . . . . . . . . . . . . . . . 17 13.2. Non-normative references . . . . . . . . . . . . . . . . . . 17 Author's Address . . . . . . . . . . . . . . . . . . . . . . 18 Intellectual Property and Copyright Statements . . . . . . . 19 Richardson Expires December 27, 2007 [Page 2] Internet-Draft btns-abstract-api June 2007 1. Overview 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 [RFC2119]. Richardson Expires December 27, 2007 [Page 3] Internet-Draft btns-abstract-api June 2007 2. Introduction Purpose of this API. Richardson Expires December 27, 2007 [Page 4] Internet-Draft btns-abstract-api June 2007 3. Objects involved There are two major kinds of objects that are defined by this document. These are the Protection Token (pToken) and the Identity Token (iToken). Both objects are abstracted into unique opaque tokens which may be manipulated only indirectly by applications. Each object has a series of attributes associated with it. The API provides a mechanism to query the value of attributes of the token. The attributes are where all of the content of the objects are. Each token has a scope - the place and time in which it can be considered valid. There are many conflicting qualities that one would wish for the token, and the result is a different compromise among these qualities for each token type. The tokens should be: small easy to allocate and deallocate automatically cleaned up when an application terminates (both properly and inproperly) easily compared easily passed back in a recvmsg(2) call as auxiliary data (for pToken) 3.1. Scope of Protection Token The protection token has a per-process (i.e. per-address space) scope. The scope of the token is not related to the underlying protection provided by IPsec. The token is a handle. 3.2. Scope of Identity Token The identity token has a per-system scope, although two applications running on the same system may not be able to compare it literally. 3.3. Validity period of Protection Token The pToken is valid only within the scope of a single process. The token may not be saved in any long term storage. It is permitted for one protection token to be replaced with another (equivalent) protection token due to a node moving, suspending and resuming, or due to extended network outages, however the underlying identity token would be guaranteed to be the same. This would most Richardson Expires December 27, 2007 [Page 5] Internet-Draft btns-abstract-api June 2007 likely occur with unconnected sockets, where due to the outage/ downtime, the keying system was unable to maintain a keying channel, and had to re-create the keys from scratch. 3.4. Validity period of Identity Token The iToken may be valid across the entire system, although it may need to be turned into an external representation. Some forms of identity token may be valid across systems, but in general an identity token is only valid in reference to a local set of trust anchors. (See [RFC2692]). Richardson Expires December 27, 2007 [Page 6] Internet-Draft btns-abstract-api June 2007 4. Namespace All functions and macros defined by this API are prefixed with "ipsec_" for functions and variables, and with "IPSEC_" if they are macros or enumerated types. (cf. to appropriate POSIX section?) Whenever sensible, the enumerated values defined in [RFC2367] are used if appropriate. Richardson Expires December 27, 2007 [Page 7] Internet-Draft btns-abstract-api June 2007 5. pToken discovery An application that receives a connection using accept(2), or with recvmsg(2) needs to get a protection token that is associated with the socket. For connected sockets (such as TCP and some SCTP modes), the protection token should not change during the lifetime of the socket, so a simple process is appropriate. For unconnected sockets (such as UDP and some SCTP modes), each datagram received may be received may arrive from a different source, and therefore may have different protections applied. A protection token needs to be returned with each datagram, so it must be returned as ancilliary data with recvmsg(2). For connected sockets, the pToken will not change during the connection. (see notes about rekeying). A simple function is provided to return a pToken from a file descriptor. Many implementions are likely to implement this using getsockopt(2), but an interface in those terms is not specified in order to keep it more abstract, and therefore more portable. Richardson Expires December 27, 2007 [Page 8] Internet-Draft btns-abstract-api June 2007 6. Properties of pToken objects privacyProtected - boolean. readonly on responder, get/set on initiator. set to false if the connection has either no privacy configured (AH, ESP-null), or if the privacy configured is known to be untrustworthy by the administrator. Returns true otherwise. (XXX: False does not mean that there will be no IPsec, but that it should not be considered useful) integrityProtected - boolean. readonly on responder, get/set on initiator. set to false if there is no data integrity protection other than the UDP/TCP checksum. compressionAvailable - boolean. readonly on responder, get/set on initiator. Set to true if data count sent/received from socket may not map linearly to data sent/received on wire. iToken - object. readonly on responder. get/set on initiator. Set to iToken object which represents identity of remote system. auditString - string. readonly on responder and readonly on initiator after connection establishment. Contains a string which can be used in system auditing and logging functions which describes the details of the IPsec SA that was negotiated. No structure of this string may be assumed. No session keys are disclosed by this string. Richardson Expires December 27, 2007 [Page 9] Internet-Draft btns-abstract-api June 2007 7. Properties of iToken objects auditString - string. readonly on responder and readonly on initiator after connection establishment. Contains a string which can be used in system auditing and logging functions which describes the remote identity, and the method by which it was authenticated (i.e. it may list the CA or origin of a public key) authenticationMethod - enumerated type. Indicates which method was used to authenticate the peer, possible values are: NONE - the peer was not authenticated in anyway BTNS - the peer was authenticated using an inline key which was not verified in anyway LEAFOFFAITH - the peer was authenticated using a key which was previously cached, but was previously received inline, and was not verified in anyway. PRESHAREDKEY - the peer was authenticated using a unique pre- shared key GROUPKEY - the peer was authenticated using a non-unique pre- shared key XAUTH - the type of phase1/PARENT-SA is not relevant, as the peer was authenticated using a username/password. EAP - the type of phase1/PARENT-SA is not relevant, as the peer was authenticated using an EAP method. (Additional properties may provide more information) PKIX_TRUSTED - the peer was authenticated using a PKIX/X.509 certificate that was found in the trusted store. PKIX_INLINE - the peer was authenticated using a PKIX/X.509 certificate that was transmitted inline, and was verified by using a Certificate Authority that was found in the trusted store. PKIX_OFFLINE - the peer was authenticated using a PKIX/X.509 certificate that was retrieved out-of-band (such as by LDAP or HTTP), and was verified by using a Certificate Authority that was found in the trusted store. Richardson Expires December 27, 2007 [Page 10] Internet-Draft btns-abstract-api June 2007 certificateAuthorityDN - string. readonly. the Distinguished Name (DN) of certificate authority that was used to verify the key (for methods that involved PKIX) certificateDN - string. readonly. the DN of the peer that was authenticated pubKeyID - string. readonly. a somewhat unique identifier for the public key. A suggestion is to use the first 9 base64 digits of the RFC3110 public key modulus, but this is a local matter. channelBinding - binary blog. readonly. provides the concatenated set of public keys Richardson Expires December 27, 2007 [Page 11] Internet-Draft btns-abstract-api June 2007 8. Accessor Functions Methods to access the properties of the two objects are specific to the language in which the bindings are done. See YYYY for C-bindings. Richardson Expires December 27, 2007 [Page 12] Internet-Draft btns-abstract-api June 2007 9. Security Considerations Probably lots to say here. Please help. Richardson Expires December 27, 2007 [Page 13] Internet-Draft btns-abstract-api June 2007 10. IANA Considerations There are no registries created by this document. The names (and language specific enum, if applicable) of the pToken and iToken proprties are internal to a single system, and therefore do not need standization. Richardson Expires December 27, 2007 [Page 14] Internet-Draft btns-abstract-api June 2007 11. Acknowledgments stuff Richardson Expires December 27, 2007 [Page 15] Internet-Draft btns-abstract-api June 2007 12. TRACKING Document RCS tracking info $Revision: 1.1 $ $Log: ietf-btns-abstract-api-00.txt,v $ Revision 1.1 2007/06/25 15:37:06 mcr added ietf-btns-abstract-api Revision 1.1 2007/06/25 15:34:08 mcr renamed drafts in Makefile Revision 1.3 2007/05/14 19:56:37 mcr added abstract Revision 1.2 2007/05/12 20:38:56 mcr fixed id string Revision 1.1 2007/05/12 01:31:00 mcr updates to abstract api document Revision 1.4 2007/02/16 03:24:09 mcr updated to make XML happy, and dates corrected Revision 1.3 2007/02/16 03:04:44 mcr C API document. Revision 1.2 2006/03/21 22:02:47 mcr added API requirements and skeleton of original API spec Revision 1.1 2006/03/21 21:04:43 mcr added documents from ipsp WG Revision 1.1 2003/06/03 20:45:06 mcr initial template Figure 1: document tracking Richardson Expires December 27, 2007 [Page 16] Internet-Draft btns-abstract-api June 2007 13. References 13.1. Normative references [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2367] McDonald, D., Metz, C., and B. Phan, "PF_KEY Key Management API, Version 2", RFC 2367, July 1998. [RFC2692] Ellison, C., "SPKI Requirements", RFC 2692, September 1999. 13.2. Non-normative references [RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005. Richardson Expires December 27, 2007 [Page 17] Internet-Draft btns-abstract-api June 2007 Author's Address Michael C. Richardson Sandelman Software Works 470 Dawson Avenue Ottawa, ON K1Z 5V7 CA Email: mcr@sandelman.ottawa.on.ca URI: http://www.sandelman.ottawa.on.ca/ Richardson Expires December 27, 2007 [Page 18] Internet-Draft btns-abstract-api June 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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, THE IETF TRUST 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. 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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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Richardson Expires December 27, 2007 [Page 19]