Tech-invite3GPPspaceIETF RFCsSIP
929190898887868584838281807978777675747372717069686766656463626160595857565554535251504948474645444342414039383736353433323130292827262524232221201918171615141312111009080706050403020100
in Index   Prev   Next

RFC 4059

Internet X.509 Public Key Infrastructure Warranty Certificate Extension

Pages: 9
Informational

ToP   noToC   RFC4059 - Page 1
Network Working Group                                     D. Linsenbardt
Request for Comments: 4059                                    S. Pontius
Category: Informational                                      A. Sturgeon
                                                                  SPYRUS
                                                                May 2005

                Internet X.509 Public Key Infrastructure
                     Warranty Certificate Extension

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 (2005).

Abstract

This document describes a certificate extension to explicitly state the warranty offered by a Certificate Authority (CA) for the certificate containing the extension.

1. Introduction

The warranty certificate extension identifies the warranty policy associated with a X.509 public key certificate [X.509-97, PROFILE]. Often the Certificate Authority (CA) will obtain an insurance policy to ensure coverage of the warranty. The certificate warranty provides an extended monetary coverage for the end entities. The certificate warranty primarily concerns the use, storage, and reliance on a certificate by a subscriber, a relying party, and the CA. It is common for a CA to establish reliance limits on the use of a certificate. It is not uncommon for a CA to attempt through contractual means to exclude its liability entirely. However, this undermines the confidence that commerce requires to gainfully use certificates. Alternatively a CA may provide extended coverage for the use of the certificate. Usually, the subscriber pays for the extended warranty coverage. In turn, subscribers are covered by an appropriately drafted insurance policy. The certificate warranty is backed by an insurance policy issued by a licensed insurance company, which results in a financial backing that is far greater than that of the
ToP   noToC   RFC4059 - Page 2
   CA.  This extra financial backing provides a further element of
   confidence necessary to encourage the use of certificates in
   commerce.

   A relying party that has a warranty from a CA may obtain compensation
   from a CA depending on the conditions for such compensation expressed
   in either the CA's Certificate Policy, the CA's insurance policy, or
   both.  Evidence of an extended warranty, provided through the
   certificate extension, will give the relying party additional
   confidence that compensation is possible, and therefore will enhance
   trust in the process.  Risk for a non-subscriber relying party may be
   reduced by the presence of a warranty extension with an explicit
   warranty stated.  The warranty extension allows this aspect of risk
   management to be automated.

   When a certificate contains a warranty certificate extension, the
   extension MUST be non-critical, and MUST contain either a NULL to
   indicate that no warranty is provided or base warranty data to
   indicate that a warranty is provided.  The extension MAY contain
   optional qualifiers.

1.1. 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 [RFC2119].

2. Warranty Extension Format

Like all X.509 certificate extensions, the warranty certificate extension is defined using ASN.1 [X.208-88, X.209-88]. The non-critical warranty extension is identified by id-pe-warranty. PKIX Object Identifier Registry id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) } PKIX Arcs id-mod OBJECT IDENTIFIER ::= { id-pkix 0 } -- modules id-pe OBJECT IDENTIFIER ::= { id-pkix 1 } -- private certificate extensions PKIX modules id-mod-warranty-extn OBJECT IDENTIFIER ::= { id-mod 27 } id-pe-warranty OBJECT IDENTIFIER ::= { id-pe 16 }
ToP   noToC   RFC4059 - Page 3
   A non-null warranty always includes a base warranty.  The warranty
   information includes the period during which the warranty applies, a
   warranty value, and a warranty type.  The warranty type tells the
   warranty limit against claims.  The extension definition supports two
   alternatives: aggregated and per-transaction.  With aggregation,
   claims are fulfilled until a ceiling value is reached.  After that,
   no further claims are fulfilled.  With per-transaction, a ceiling
   value is imposed on each claim, but each transaction is considered
   independently.

   The warranty extension permits inclusion of two optional warranty
   qualifiers.  The first qualifier provides extended warranty
   information, the second provides a pointer to the warranty terms and
   conditions.

   When present, the extended warranty information provides information
   about coverage beyond the scope of the base warranty.  Like the base
   warranty information, the extended warranty information includes the
   period during which the warranty applies, a warranty value, and a
   warranty type.

   When present, the terms and conditions pointer provides a reference
   to a document containing the terms and conditions associated with the
   warranty.  The document may be a Certificate Policy that contains
   this information, a document specifically about the warranty, or a
   Relying Party Agreement.  The pointer is always a uniform resource
   locator (URL).  The URL MUST be a non-relative URL using the http
   scheme.  The URL MUST follow the URL syntax and encoding rules
   specified in RFC 3986 [URI].

2.1. Warranty Extension Syntax

The syntax for the warranty extension is: Warranty ::= CHOICE { none NULL, -- No warranty provided wData WarrantyData } -- Explicit warranty WarrantyData ::= SEQUENCE { base WarrantyInfo, extended WarrantyInfo OPTIONAL, tcURL TermsAndConditionsURL OPTIONAL } WarrantyInfo ::= SEQUENCE { validity WarrantyValidityPeriod, amount CurrencyAmount, wType WarrantyType }
ToP   noToC   RFC4059 - Page 4
   WarrantyValidityPeriod  ::=  CHOICE  {
     sameAsCertificate    NULL,
     explicitPeriod       ValidityPeriod  }

   ValidityPeriod  ::=  SEQUENCE  {
     notBefore            GeneralizedTime,
     notAfter             GeneralizedTime  }

   -- CurrencyAmount specifies the currency and a monetary value.
   -- Currency codes are defined in [ISO4217].  The monetary value
   -- is: amount / (10 ** amtExp10), and the exponent MUST be the
   -- minor unit of currency specified in [ISO4217].

   CurrencyAmount  ::=  SEQUENCE  {
     currency             INTEGER (1..999),
     amount               INTEGER (0..MAX),
     amtExp10             INTEGER (0..MAX)  }

   WarrantyType  ::=  INTEGER  {
     aggregated           (0),
     perTransaction       (1)  }

   TermsAndConditionsURL  ::=  IA5String  -- MUST use http scheme

2.2. Warranty Extension Semantics

Warranty is a CHOICE; it is represented either by NULL or WarrantyData. If the CA selects NULL, then the CA is explicitly stating that no warranty is provided. If the CA selects WarrantyData, then the CA is explicitly stating that a warranty is provided, and the fields within the WarrantyData type MUST provide details about that warranty. WarrantyData MUST contain information about the base warranty. WarrantyData MAY contain information about an extended warranty. Both base warranty and extended warranty information is provided using the WarrantyInfo type. WarrantyData MAY contain a URL that points to the terms and conditions of the warranty. The URL is provided using the TermsAndConditionsURL type, which is an IA5 string. The IA5String MUST contain a URI [URI] using the http scheme, such as "http://www.example.com/warranty/t_and_c.html". WarrantyInfo MUST contain the warranty validity period, the currency amount of the warranty, and the type of warranty. The warranty validity period is provided using the WarrantyValidityPeriod type. The currency amount of the warranty is provided using the CurrencyAmount type. The type of warranty is provided using the WarrantyType type.
ToP   noToC   RFC4059 - Page 5
   WarrantyValidityPeriod is a CHOICE; it is represented either by NULL
   or ValidityPeriod.  If the CA selects NULL, then the validity periods
   of the warranty and the certificate MUST be exactly the same.  If the
   CA selects ValidityPeriod, then the CA is explicitly stating a
   warranty validity period that is different than the validity period
   of the certificate.  If the validity periods of the warranty and the
   certificate are the same, then the CA MUST select the NULL choice.
   The validity periods are expected to be the same in the vast majority
   of the cases.  ValidityPeriod is a SEQUENCE of two GeneralizedTime
   values.  The first (notBefore) GeneralizedTime value MUST indicate
   the date and time that the warranty becomes valid, and the second
   (notAfter) GeneralizedTime value MUST indicate the date and time that
   the warranty expires.

   CurrencyAmount is a SEQUENCE of three integers which together specify
   the currency and a monetary value.  The first integer (currency) MUST
   indicate the currency using one of the currency codes defined in
   [ISO4217].  The second integer (amount) MUST indicate the value of
   the warranty.  The third integer (amtExp10) MUST indicate the correct
   placement of the decimal point in the monetary value, and MUST be the
   minor unit of currency specified in [ISO4217].  For example
   $48,525.50 (in US dollars) is represented as:

      currency =      840
      amount   =  4852550
      amtExp10 =        2

   WarrantyType is an integer.  A value of zero indicates that claims
   against the warranty will be aggregated, and once the value of
   fulfilled claims reaches the warranty currency amount, then no
   further claim will be fulfilled.  A value of one indicates that each
   claim is handled independently, but no individual claim can exceed
   the warranty currency amount.  The CA MUST select either zero or one
   for this integer value.

3. Security Considerations

The procedures and practices employed by the CA MUST ensure that the correct values for the warranty are inserted in each issued certificate. Relying parties and users may accept or reject a particular certificate for an intended use based on the information provided in warranty extension. Incorrect representation of the actual warranty may result in otherwise avoidable warranty claims for the CA.
ToP   noToC   RFC4059 - Page 6

4. IANA Considerations

Certificate extensions and extended key usage values are identified by object identifiers (OIDs). The OIDs used in this document are derived from X.509 [X.509-97]. No further action by the IANA is necessary for this document or any anticipated updates.

5. ASN.1 Module

WarrantyExtn { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-warranty-extn(27) } DEFINITIONS IMPLICIT TAGS ::= BEGIN -- OID Arcs id-pe OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) 1 } -- Warranty Extension id-pe-warranty-extn OBJECT IDENTIFIER ::= { id-pe 16 } Warranty ::= CHOICE { none NULL, -- No warranty provided wData WarrantyData } -- Explicit warranty WarrantyData ::= SEQUENCE { base WarrantyInfo, extended WarrantyInfo OPTIONAL, tcURL TermsAndConditionsURL OPTIONAL } WarrantyInfo ::= SEQUENCE { validity WarrantyValidityPeriod, amount CurrencyAmount, wType WarrantyType } WarrantyValidityPeriod ::= CHOICE { sameAsCertificate NULL, explicitPeriod ValidityPeriod }
ToP   noToC   RFC4059 - Page 7
   ValidityPeriod ::= SEQUENCE  {
       notBefore            GeneralizedTime,
       notAfter             GeneralizedTime  }

   -- CurrencyAmount specifies the currency and a monetary value.
   -- Currency codes are defined in [ISO4217].  The monetary value
   -- is: amount / (10 ** amtExp10), and the exponent MUST be the
   -- minor unit of currency specified in [ISO4217].

   CurrencyAmount ::= SEQUENCE  {
       currency             INTEGER (1..999),
       amount               INTEGER (0..MAX),
       amtExp10             INTEGER (0..MAX)  }

   WarrantyType ::= INTEGER {
       aggregated           (0),
       perTransaction       (1)  }

   TermsAndConditionsURL ::= IA5String

   END

6. Normative References

[ISO4217] ISO. "Codes for the Representation of Currencies and Funds", ISO 4217. 1995. [PROFILE] Housley, R., Ford, W., Polk, W., and D. Solo, "Internet X.509 Public Key Infrastructure Certificate and CRL Profile", RFC 2459, January 1999. [URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [X.208-88] CCITT. Recommendation X.208: Specification of Abstract Syntax Notation One (ASN.1). 1988. [X.209-88] CCITT. Recommendation X.209: Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1). 1988.

7. Informative References

[X.509-97] ITU-T. Recommendation X.509: The Directory- Authentication Framework. 1997.
ToP   noToC   RFC4059 - Page 8

Acknowledgements

This document was developed with the expertise and support of Russ Housley, Vigil Security LLC, and Dr. Adrian McCullagh, Freehills Australia.

Authors' Addresses

Duane Linsenbardt SPYRUS 2355 Oakland Road Suite 1 San Jose CA 95131 USA EMail: dlinsenbardt@spyrus.com Sue Pontius SPYRUS 2355 Oakland Road Suite 1 San Jose CA 95131 USA EMail: spontius@spyrus.com Alice Sturgeon SPYRUS Suite 1502, 222 Queen St., Ottawa ON K0A 2T0 Canada EMail: asturgeon@spyrus.com
ToP   noToC   RFC4059 - Page 9
Full Copyright Statement

   Copyright (C) The Internet Society (2005).

   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 currently provided by the
   Internet Society.