RE: Clean copy of CEM
Kyle Meadors <kyle <at> drummondgroup.com>
2005-07-12 13:03:56 GMT
Shan,
Try this.
I checked the IETF site and I see the odd
characters there as well. Will fix this on the next revision.
From:
owner-ietf-ediint <at> mail.imc.org [mailto:owner-ietf-ediint <at> mail.imc.org] On Behalf Of Shan Harter
Sent: Monday, July 11, 2005 6:53
PM
To: ietf-ediint <at> imc.org
Subject: Clean copy of CEM
The CEM protocol document contains some
unknown characters. This was also downloaded from IETF and, it too contains
these characters, such as an
Most of them are apostrophes and other
punctuation, but instead of me guessing, does anyone have a "clean"
copy of the CEM draft?
Shan
Shan Harter
VP of Project Services
PEBS, Inc.
TempeArizona,
85284
ph: 480-756-6777 Ext 205,
fax: 480-756-9755, cell: 602-821-2951
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Draft CEM for EDIINT February 2005
Private Working Group K. Meadors
Internet-Draft Drummond Group Inc.
Document: draft-meadors-certificate-exchange- D. Moberg
01.txt Cyclone Commerce
Expires: August 2005 February 2005
Certificate Exchange Messaging for EDIINT
draft-meadors-certificate-exchange-01.doc
By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed,
or will be disclosed, and any of which I become aware will be
disclosed, in accordance with RFC 3668.
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.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Any questions, comments, and reports of defects or ambiguities in
this specification may be sent to the mailing list for the EDIINT
working group of the IETF, using the address <ietf-ediint <at> imc.org>.
Requests to subscribe to the mailing list should be addressed to
<ietf-ediint-request <at> imc.org>.
Abstract
The EDIINT AS1, AS2 and AS3 message formats do not currently contain
any neutral provisions for transporting and exchanging trading
partner profiles or digital certificates. EDIINT Certificate Exchange
Messaging provides the format and means to effectively exchange
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certificates for use within trading partner relationships. The
messaging consists of two types of messages, Request and Response,
which allow trading partners to communicate certificates, their
intended usage and their acceptance through XML. Certificates can be
specified for use in digital signatures, data encryption or SSL/TLS
over HTTP (HTTPS).
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.
Feedback Instructions
NOTE TO RFC EDITOR: This section should be removed by the RFC editor
prior to publication.
If you want to provide feedback on this draft, follow these
guidelines:
-Send feedback via e-mail to kyle <at> drummondgroup.com, with
"Certificate Exchange" in the Subject field.
-Be specific as to what section you are referring to, preferably
quoting the portion that needs modification, after which you state
your comments.
-If you are recommending some text to be replaced with your suggested
text, again, quote the section to be replaced, and be clear on the
section in question.
Table of Contents
1. Introduction...................................................3
1.1 Overview...................................................3
1.2 Terminology and Key Word Convention........................4
1.3 Certificate Lifecycle......................................5
2. Message Processing.............................................6
2.1 Message Structure..........................................6
2.2 Version Header.............................................7
2.3 Certificate Exchanging.....................................7
2.4 Certificate Implementation.................................8
2.5 CEM Response...............................................9
3. XML Schema Description........................................10
3.1 EDIINTCertificateExchangeRequest element..................10
3.2 EDIINTCertificateExchangeResponse element.................13
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4. Use Case Scenarios............................................14
4.1 Maintenance Configuration Processing......................14
4.2 Initial Configuration Processing..........................15
5. Profile Exchange Messaging....................................17
6. Security Considerations.......................................18
7. IANA Considerations...........................................18
8. References....................................................19
8.1 Normative References......................................19
8.2 Informative References....................................20
9. Acknowledgments...............................................20
Author's Addresses...............................................20
Appendix.........................................................21
A.1 EDIINT Certificate Exchange XML Schema....................21
A.2 Example of EDIINT Certificate Exchange Request XML........23
A.3 Example of EDIINT Certificate Exchange Response XML.......24
Changes from Previous Versions...................................24
B.1 Updates from Version 00...................................25
1.
Introduction
1.1
Overview
The growth and acceptance of EDIINT protocols, AS1, AS2 and AS3, in
numerous supply-chains was due in part to the security feature which
was provided. The security is not possible without the digital
certificates which enable it. To maintain the level of security
necessary to transmit business documentation, existing certificates
must occasionally be replaced and exchanged with newer ones. The
exchanging of digital certificates is unavoidable given how
certificates can expire or become compromised. Complicating this is
supply-chains which cannot afford to shutdown their business
transactions while trading partners laboriously upload new
certificates. Certificate exchange must be accomplished in a reliable
and seamless format so as not to affect ongoing business
transactions.
This document describes how EDIINT products may exchange public-key
certificates. Since EDIINT is built upon the security provided by
public-private key pairs, it is vital that implementers are able to
update their trading partners with new certificates as their old
certificates expire, become outdated or insecure. EDIINT Certificate
Exchange Messaging (CEM) described here utilizes XML data to exchange
the certificate and provide information on its intended usage and
acceptance within the trading partner relationship. There are two
types of CEM messages, the CEM Request which presents the new
certificate to be introduced into the trading partner relationship
and the CEM Response which is the recipients response to the CEM
Request. CE messages can be exchanged through AS1 [AS1], AS2 [AS2] or
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AS3 [AS3] message transports. However, it is possible to leverage CE
messaging through other transport standards besides EDIINT.
1.2
Terminology and Key Word Convention
[RFC2818] provides a glossary of Internet security terms, and several
of their definitions are listed here verbatim. However, some
definitions required for this document were undefined by [RFC2818] or
rewritten to better explain their specific use within CEM.
Certificate A digital certificate contains the owners (End
Entitys) name, the issuers name, a serial number, expiration date,
and a copy of the owners Public Key. The Public Key is used for
Encrypting messages and Verifying Signatures (verifying a signature
is also called Authentication).
Certificate Revocation List (CRL) A data structure that enumerates
digital certificates that have been invalidated by their issuer prior
to when they were scheduled to expire. [RFC2828]
Certification Authority (CA) An entity that issues digital
certificates (especially X.509 certificates) and vouches for the
binding between the data items in a certificate. [RFC2828]
CA Certificate - A certificate issued by a trusted certification
authority. CA certificates are not used to encrypt data but to sign
other certificates. CA certificates are signed by themselves, but are
not considered self-signed certificates for the purpose of this
document.
Certification Hierarchy - In this structure, one CA is the top CA,
the highest level of the hierarchy. The top CA may issue public-key
certificates to one or more additional CAs that form the second
highest level. Each of these CAs may issue certificates to more CAs
at the third highest level, and so on. The CAs at the second-lowest
of the hierarchy issue certificates only to non-CA entities, called
"end entities" that form the lowest level. Thus, all certification
paths begin at the top CA and descend through zero or more levels of
other CAs. All certificate users base path validations on the top
CA's public key. [RFC2828]
CEM Request The EDIINT Certificate Exchange Messaging (CEM) Request
is one of two possible CEM messages. It presents a certificate to be
introduced into the trading partner relationship along with relevant
information on how it is to be implemented.
CEM Response The EDIINT Certificate Exchange Messaging (CEM)
Response is one of two possible CEM messages. It is the response to
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the CEM Request indicating whether or not the end entity certificate
present in the CEM Request was accepted.
End Entity A system entity that is the subject of a public-key
certificate and that is using, or is permitted and able to use, the
matching private key only for a purpose or purposes other than
signing a digital certificate; i.e., an entity that is not a CA.
[RFC2828]
End Entity Certificate - A certificate which is used to encrypt data
or authenticate a signature. (The private key associated with the
certificate is used to decrypt data or sign data). The certificate
may be self-signed or issued by a trusted certificate.
Intermediary Certificate - A certificate issued by a CA certificate
which itself issues another certificate (either intermediary or end
entity). Intermediary certificates are not used to encrypt data but
to sign other certificates.
Public Key - The publicly-disclosable component of a pair of
cryptographic keys used for asymmetric cryptography. [RFC2828]
Public Key Certificate - A digital certificate that binds a system
entity's identity to a public key value, and possibly to additional
data items. [RFC2828]
Self-signed Certificate - A certificate which is issued by itself
(both issuer and subject are the same) and is an End Entity
certificate.
1.3
Certificate Lifecycle
A certificate has five states.
1. Pending - Upon receiving a certificate from a trading partner, the
certificate is marked as Pending until a decision can be made to
trust it or if its validity period has not yet begun.
2. Rejected If a Pending certificate is not trusted, it is
considered Rejected.
3. Accepted - Once a Pending certificate has been trusted, it is
considered Accepted. An Accepted certificate may be used in
secure transactions.
4. Expired A certificate which is no longer valid because its
expiration date has passed. Expired certificates SHOULD be kept
in a certificate storehouse for decrypting and validating past
transactions.
5. Revoked A certificate which has been explicitly revoked by its
owner or the certificate authority.
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2.
Message Processing
2.1
Message Structure
CEM messages use the underlying EDIINT transport, such as AS2, to
communicate information on the certificate, its intended use and its
acceptance. Both digital certifications and the XML data describing
their intended use are stored within a multipart-related MIME
envelope [RFC2387]. The certificates are stored in certificate chains
through SMIME, certs-only MIME envelope [3851], and processing
information is XML data which is identified through the MIME content-
type of application/ediint-cert-exchange+xml. The format for CEM
messages is as follows:
Various EDIINT headers
Disposition-Notification-To: http://10.1.1.1:80/exchange/as2-company
Content-Type: multipart/signed; micalg=sha1;
protocol="application/pkcs7-signature";
boundary="--OUTER-BOUNDARY"
----OUTER-BOUNDARY
Content-Type: multipart/related; type=" application/ediint-cert-
exchange+xml"; boundary="--INNER-BOUNDARY"
----INNER-BOUNDARY
Content-Type: application/ediint-cert-exchange+xml
Content-ID: <20040101-1.alpha <at> example.org>
[CEM XML data]
----INNER-BOUNDARY
Content-Type: application/pkcs7-mime; smime-type=certs-only
Content-ID: <20040101-2.alpha <at> example.org>
[digital certificate]
----INNER-BOUNDARY--
----OUTER-BOUNDARY
Content-Type: application/pkcs7-signature
[Digital Signature]
----OUTER-BOUNDARY--
One and only one MIME type of application/ediint-cert-exchange+xml
MUST be present in the multipart/related structure, and it MUST be
the root element. Multiple certs-only media types may be included,
but at least one MUST be present. A unique content-id header MUST be
present within each of the multipart structures.
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If possible, both the CEM Request and CEM Response message SHOULD be
signed. Applying digital signatures will allow for automatic exchange
based on a previous trust relationship. However, it may not be
possible in the initial exchange of a new trading partner. If a CEM
message is signed, the signing certificate MUST be included in the
digital signature. Extra security such as applying data encryption or
compression is OPTIONAL. Also, CEM messages SHOULD request a MDN and
SHOULD request a signed MDN. The MDN can be either synchronous or
asynchronous. The MDN response verifies the transport delivery but is
not equivalent to the CEM Response message. All necessary headers
MUST be applied to the message per the underlying transport standard.
2.2
Version Header
Before a CEM Request message is generated, the initiator MUST
determine if the recipient can accept the CEM Request message. For
both AS2 and AS3, the version header value of 1.2 or greater (e.g.
1.3) indicates the implementation can both initiate and receive CEM
message exchanges. AS2 and AS3 implementers of CEM MUST utilize the
proper version header in all of their messages, both CEM messages and
normal document transport messages. Since there is no AS1 version
header, trading partners using AS1 MUST decide within the trading
partner agreement whether to utilize CEM.
For CEM Request messages of initial trading partner configurations,
the initiator MUST decide within the trading partner agreement if the
recipient can accept the CEM Request.
2.3
Certificate Exchanging
After obtaining the desired certificate, the initiator of the
certificate exchange transmits the end-entity certificate in the CEM
Request message. If the end-entity certificate is not self-signed,
then the CA certificate and any other certificates needed to create
the chain of trust for the end-entity certificate MUST be included in
the CEM Request message. Multiple end-entity certificates MAY also be
present.
The entire certificate trust chain is stored in a BER encoded P7C
format [REFERENCE LIKELY NEEDED] and placed within the SMIME certs-
only MIME envelope which is then stored in a single part of the
multipart/related structure. Each P7C trust chain MUST include a
single end-entity certificate and its trust authorities. No other
certificates are to be part of this chain. The number of P7C trust
chains in a CEM Request message MUST be equal to the number of end-
entity certificates being communicated in the CEM XML document.
If different end-entity certificates have common trust authorities
certificates, each P7C cert chain still MUST included each
certificate necessary to create a trust anchor. Thus, if a recipient
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can not create a trust relationship from the P7C cert chain, it MAY
reject the end-entity certificate in the CEM Request.
End-entity certificates are referenced and identified in the XML data
by their content-id used in the multipart-related structure.
Information on how the certificate is to be used, or certificate
usage, by the receiving user agent and other related information is
found in the XML data. A certificate can be used for a single
function, like digital signatures, or used for multiple functions,
such as both digital signatures and data encryption. If a certificate
is intended for multiple usages, such as for both digital signatures
and data encryption, the certificate MUST be listed only once in the
CEM Request message and its multiple usage listed through the
CertUsage XML element.
Upon receipt of the CEM Request, the recipient trading partner
processes the transport message as normal and returns the MDN. The
recipient MUST return the MDN before parsing and interpreting the CEM
XML data or certificate chains. The returned MDN only provides
information on the veracity of the transport message and not the
acceptance of the certificate(s) being exchanged.
2.4
Certificate Implementation
The new certificate is considered to be in the Pending state for the
recipient who MUST decide whether to accept the certificate as
trustworthy. This decision is arbitrary and left to each individual
trading partner. Upon accepting the certificate, it is to be
considered an Accepted certificate within the trading partner
relationship. If the certificate is not accepted, it is considered
Rejected.
When a certificate is intended for use in data encryption or TLS/SSL
server authentication, the initiator MUST consider the certificate to
be Accepted and be prepared for its trading partner to begin using
the certificate upon generating the CEM Request message. After a
recipient generates a positive CEM Response message for a
certificate, the recipient MUST immediately begin using the
certificate in trading with the initiator of the request. The
recipient MAY apply encryption to the CEM Response message using the
new Accepted certificate or MAY apply encryption to the CEM Response
message using the previously Accepted encryption certificate.
When a certificate is intended for use in digital signatures or
TLS/SSL client authentication, the initiator MUST NOT use the
certificate until the recipient trading partner generates a CEM
Response accepting the certificate or the respond by date, which is
listed in the RespondByDate XML element. The initiator MAY use the
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certificate after the respond by date, regardless of whether the
partner has accepted it or not. The certificate used for the digital
signature of the CEM Request message MUST be the one which is
currently Accepted within the trading partner relationship.
Since implementers of EDIINT often use the same certificate with
multiple trading partners, implementers of CEM MUST be able to keep
both the old and new certificates as Accepted. If the initiator has
generated a CEM Request and exchanged a new encryption certificate to
multiple trading partners, it MUST be able to accept encrypted data
which uses either the older, existing encryption certificate or the
newly exchanged encryption certificate. Likewise, a recipient of a
CEM Request MUST be able to authenticate digital signatures using
either the new or old certificates, since the initiator may not be
able to switch certificates until all trading partners accept the new
certificate. Similar provisions MUST be made for certificates
intended for TLS/SSL server and client authentication. Revoking a
certificate MUST be done outside of CEM.
If a CEM Request message contains a certificate which is currently
Accepted and has the identical usage for the certificate that has
been Accepted, the recipient MUST NOT reject the duplicate
certificate but MUST respond with a CEM Response message indicating
the certificate has been accepted. For example, if Certificate A is
currently Accepted as the encryption certificate for a user agent,
any CEM Request message containing Certificate A with the usage as
the encryption only MUST be accepted by an existing trading partner.
This situation may be necessary for an implementation intending to
verify its current trading partner certificate.
If two trading partners utilize multiple EDIINT protocols for
trading, such as AS2 for a primary transport and AS1 as the backup
transport, it is dependent upon implementation and trading partner
agreement how CEM messages are sent and which transports the
exchanged certificates affect.
2.5
CEM Response
If a CEM Request is received, the recipient MUST respond with a CEM
Response message indicating if the certificate is Accepted or
Rejected. If multiple end-entity certificates were included within
the CEM Request, the recipient MAY generate individual CEM Response
messages for each certificate or the recipient MAY consolidate
responses for multiple certificates in one or more CEM Response
messages. CEM Response are NOT sent for any certificates other than
end-entity certificates. Based on the CEM Response message, the
initiator determines if the exchanged certificate may be used in
future trading with the recipient partner.
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The recipient SHOULD NOT generate more than one CEM Response for a
given end-entity certificate. If the recipient sends more than one
response, the action of the originator of the CEM Request is not
defined.
3.
XML Schema Description
The CEM schema has two top-level elements,
EDIINTCertificateExchangeRequest and
EDIINTCertificateExchangeResponse. The
EDIINTCertificateExchangeRequest element is present only in the CEM
Request message, and the EDIINTCertificateExchangeResponse is present
only in the CEM Response message. All other elements nest directly or
indirectly from these. Please refer to the appendix for the actual
schema document.
3.1
EDIINTCertificateExchangeRequest element
EDIINTCertificateExchangeRequest contains two elements,
TradingPartnerInfo, which can only appear once and TrustRequest,
which may be present multiple times. TrustRequest contains
information on a certificate and its intended usage.
TradingPartnerInfo exists to provide information on the publication
of the CEM Request message since processing of the XML data may occur
apart from the handling of the accompanying transport message, for
example the AS2 request.
<xs:element name="EDIINTCertificateExchangeRequest">
<xs:complexType>
<xs:sequence>
<xs:element ref="tns:TradingPartnerInfo"/>
<xs:element name="TrustRequest"
type="tns:TrustRequestType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
TradingPartnerInfo identifies the entity that created the CEM message
through the nested Name element. Both the optional qualifier
attribute and the element value of Name are left open to the
implementer, but some suggested choices are to list the EDI
identification or the transport trading partner relationship, for
example the qualifier of AS2 and the value of the AS2 system
identifier (AS2-From value). MessageOriginated is included in
TradingPartnerInfo to identify the time and date the message was
created. The MessageOriginated date and time values MUST follow XML
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standard dateTime type syntax and be listed to at least the nearest
second and expressed in local time with UTC offset.
<xs:element name="TradingPartnerInfo">
<xs:complexType>
<xs:sequence>
<xs:element name="Name">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="qualifier"
type="xs:string" use="optional"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
<xs:element name="MessageOriginated" type="xs:dateTime"/>
</xs:sequence>
</xs:complexType>
</xs:element>
The TrustRequest element contains the EndEntity, CertUsage,
RespondByDate and ResponseURL elements. The required EndEntity
element is found only once in a TrustRequest element and contains the
content-id reference to the end-entity certificate being exchanged.
<xs:complexType name="TrustRequestType">
<xs:sequence>
<xs:element ref="tns:CertUsage" maxOccurs="unbounded"/>
<xs:element ref="tns:RespondByDate"/>
<xs:element ref="tns:ResponseURL"/>
<xs:element name="EndEntity" type="tns:EndEntityType"/>
</xs:sequence>
</xs:complexType>
EndEntity contains the nested elements of CertificateIdentifier and
CertificateContentID. CertificateContentID is a string element which
references the content-id of the multipart/related structure where
the certificate is stored. CertificateIdentifier comes from the XML
Signature schema namespace [XML-DSIG].
<xs:complexType name="EndEntityType">
<xs:sequence>
<xs:element name="CertificateIdentifier"
type="ds:X509IssuerSerialType"/>
<xs:element name="CertificateContentID" type="xs:string"/>
</xs:sequence>
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CertificateIdentifier contains the string element X509IssuerName and
the integer element X509SerialNumber. X509SerialNumber is the
assigned serial number of the end entity certificate as it is listed.
X509IssuerName contains the issuer name information of the end-entity
certificate, such as common name, organization, etc. This information
can be described in any format, but it is RECOMMENDED to list each
issuer attribute abbreviation [X.520] [PROFILE] followed by the equal
sign (i.e. =), then separating each attribute listing by a single
semi-colon (e.g. CN=The Common Name;O=Organization;
). Refer to the
appendix and the sample CEM Request message for an example of the
X509IssuerName.
<complexType name="X509IssuerSerialType">
<sequence>
<element name="X509IssuerName" type="string"/>
<element name="X509SerialNumber" type="integer"/>
</sequence>
</complexType>
CertUsage is an unbounded element which contains enumerated values on
how the exchanged certificate is to be used. There are enumerated
values for SMIME digital signatures (digitalSignature), SMIME data
encryption (keyEncipherment), the server certificate used in TLS
transport encryption (tlsServer) and the client certificate used in
TLS transport encryption (tlsClient). While the element is unbounded,
CertUsage only has a potential number of four occurrences due to the
limit of the enumerated values.
<xs:element name="CertUsage" type="tns:CertUsageType"/>
<xs:simpleType name="CertUsageType">
<xs:restriction base="xs:string">
<xs:enumeration value="tlsClient"/>
<xs:enumeration value="tlsServer"/>
<xs:enumeration value="keyEncipherment"/>
<xs:enumeration value="digitalSignature"/>
</xs:restriction>
</xs:simpleType>
RespondByDate is a required element of the XML standard dateTime type
expressed in local time with UTC offset, which provides information
on when the certificate should be trusted, inserted into the trading
partner relationship and responded to by a CEM Response message. If
the certificate can not be trusted or inserted into the trading
partner relationship, the CEM Response message should still be
returned by the date indicated.
<xs:element name="RespondByDate" type="xs:dateTime"/>
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ResponseURL is an element which indicates where the CEM Response
message should be sent. This value takes precedence over the existing
inbound URL of the current trading partner relationship. The Response
MUST use the same transport protocol (AS1, AS2, or AS3) as the
Request.
<xs:element name="ResponseURL" type="xs:anyURI"/>
3.2
EDIINTCertificateExchangeResponse element
EDIINTCertificateExchangeResponse contains the two elements
TradingPartnerInfo and TrustResponse. TradingPartnerInfo, which is
also found in EDIINTCertificateExchangeRequest, describes the trading
partner generating this response message. TrustResponse provides
information on the acceptance of a previously sent end entity
certificate. There can be multiple TrustResponse elements within an
EDIINTCertificateExchangeResponse.
<xs:element name="EDIINTCertificateExchangeResponse">
<xs:complexType>
<xs:sequence>
<xs:element ref="tns:TradingPartnerInfo"/>
<xs:element name="TrustResponse"
type="tns:TrustResponseType"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:complexType name="TrustResponseType">
<xs:sequence>
<xs:element ref="tns:CertStatus"/>
<xs:element ref="tns:ReasonForRejection" minOccurs="0"/>
<xs:element name="CertificateReference"
type="ds:X509IssuerSerialType"/>
</xs:sequence>
</xs:complexType>
A TrustResponse element identifies a certificate which has been
previously exchanged within the trading partner relationship through
a CEM Request and now has been either accepted or rejected by the
partner. The CertificateReference element is of the same type as the
CertificateIdentifier element. A CertificateReference element in a
CEM Response MUST be identical to its CertificateIdentifier
counterpart in the associated CEM Request since they identify the
same certificate in question.
The required element CertStatus has the enumerated values of
Accepted or Rejected. Accepted indicates the certificate was
trusted by the trading partner and is now ready for use within the
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trading partner relationship, and Rejected indicates the
certificate is not trusted by the trading partner nor can it be
currently used with the trading partner relationship. If the value of
Rejected is chosen, the optional string element ReasonForRejection
may be included. If present, ReasonForRejection should contain a
brief description of why the certificate was not accepted. Since the
value for this element is not enumerated but open, it MUST be
interpreted through human means.
<xs:element name="CertStatus" type="tns:CertStatusType"/>
<xs:simpleType name="CertStatusType">
<xs:restriction base="xs:string">
<xs:enumeration value="Rejected"/>
<xs:enumeration value="Accepted"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="ReasonForRejection" type="xs:string"/>
4.
Use Case Scenarios
These scenarios illustrate how the request and response messages
described in Section 2 and 3 can be used to exchange certificates.
The requirements of this standard are in Section 2 and 3; this
section is only illustrative.
4.1
Maintenance Configuration Processing
This use case assumes an established relationship with currently
working certificates. Examples of this use case include, but are not
limited to a certificate with an expiration date approaching. If the
current certificate is used to sign the Certificate Exchange
messages, this signature can be used to establish a level of trust in
the transaction. For this example, the AS2 transport protocol is
used.
4.1.1. Step 1
Initiator creates an EDIINTCertificateExchangeRequest as described in
Section 2. Message Processing and Section 3. XML Schema Description
and sends it according to EDIINT-AS2 protocol. A positive MDN
received during this step indicates successful transmission of the
message but does not imply successful action on the certificate. In
the case of an encryption certificate, the initiator MUST be
immediately ready to receive documents encrypted with the new
certificate. In the case of a signing certificate, the initiator can
begin signing documents with the new certificate at the RespondByDate
or upon receipt of an EDIINTCertificateExchangeResponse from the
partner indicating acceptance of the certificate. If an acceptance
response is not received by the RespondByDate, the initiator may or
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may not begin signing with the new certificate, depending on the
implementations capabilities and the policies of the initiator.
4.1.2. Step 2
Receiver validates the EDIINTCertificateExchangeRequest message at
the AS2 level and returns a correct MDN. If the message is a proper
AS2 document, the receiver MUST automatically accept or reject the
new certificate(s) or require manual intervention. If the certificate
is automatically accepted or rejected, an
EDIINTCertificateExchangeResponse MUST be generated and returned to
the initiator. Since the trading relationship could be hindered if
action is not taken prior to the RespondByDate, manual intervention
MUST be done before that date. When the manual intervention
determines to accept or reject the new certificate, an
EDIINTCertificateExchangeResponse MUST be generated and returned to
the initiator. Both automatic and manual
EDIINTCertificateExchangeResponses MUST be formatted according to
Section 2. Message Processing and Section 3. XML Schema Description
and sent according to EDIINT-AS2 protocol. A positive MDN received
for the response message indicates successful transmission of the
response message.
After the receiver accepts the new certificate and returns an
acceptance response, the receiver encrypts all messages to the
initiator with the new encryption certificate. The receiver
continues to accept messages from the initiator that are signed with
the old signing certificate, and also accepts messages signed with
the new signing certificate. The initiator may start signing with
the new certificate when it receives the acceptance response, or when
it receives acceptance responses from all its partners, or after the
RespondByDate, or when the old signing certificate expires.
4.1.3. Step 3
After the exchange is complete, some cleanup may be desirable,
including retiring or archiving the old certificates. This step is
considered an implementation detail that is left purely to the
vendors and users.
4.2
Initial Configuration Processing
This use case assumes all necessary elements of an EDIINT
relationship exist outside of the certificates, including an
understanding of the partners ability to support a CEM.
Establishing these elements may be accomplished via an automated
exchange, a manual process, or any other method desirable. No
methods of exchanging the additional information are described in
this specification. Examples of this use case include, but are not
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limited to the first exchange of a certificate, or recovery from an
expired or compromised certificate. This case assumes no signing
certificate has been established, precluding a signature being used
to establish a level of trust. Therefore, extra precautions may be
appropriate in this use case. There are additional use cases
possible where some certificates are already established. It is not
practical to cover every case here, but this case and the maintenance
case should give sufficient guidance.
4.2.1. Step 1
Initiator creates an EDIINTCertificateExchangeRequest as described in
Section 2.0 Message Format and Section 3.0 XML Schema. The initiator
sends it according to EDIINT-AS2 protocol. Using a digital signature
on the AS2 message is optional, as the receiver will not be able to
verify until after accepting the signature certificate. If the
receiver supports this use case, they MUST accept this message
regardless of the presence of a signature. Unless the initiator
possesses the receivers encryption certificate, encryption MUST NOT
be used. Unless the initiator possesses the receivers signature
certificate, they SHOULD NOT request a signed MDN. If the MDN is not
signed, there is no legal proof the receiver received the message.
In addition, a positive MDN received during this step gives some
indication of successful transmission of the message, but does not
imply successful action on the certificate. In the case of an
encryption certificate, the initiator MUST be immediately ready to
receive documents encrypted with the new certificate. In the case of
a signing certificate, the initiator can begin signing documents with
the new certificate at the RespondByDate or upon receipt of an
EDIINTCertificateExchangeResponse from the partner indicating they
are ready. If an acceptance response is not received by the
RespondByDate, the initiator may or may not begin signing with the
new certificate, depending on the implementations capabilities and
the policies of the initiator.
4.2.2. Step 2
Receiver validates the EDIINTCertificateExchangeRequest message at
the AS2 level and returns an MDN according to the EDIINT-AS2
protocol. If the message is a proper AS2 document, the receiver MUST
automatically accept or reject the new certificate(s), or require
manual intervention. Caution should be used in automatically
accepting the certificate, as it may be impossible to verify the
sender is authentic. If the certificate is automatically accepted or
rejected, an EDIINTCertificateExchangeResponse MUST be generated and
returned to the initiator. Since the trading relationship could be
hindered if action is not taken prior to the RespondByDate, manual
intervention MUST be done before that date. When the manual
intervention determines to accept or reject the certificate, an
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EDIINTCertificateExchangeResponse MUST be generated and returned to
the initiator.
In both the automatic and manual case, the
EDIINTCertificateExchangeResponses MUST be formatted according to
Section 2. Message Processing and Section 3. XML Schema Description
and sent according to EDIINT-AS2 protocol. If the original CEM
included the encryption certificate, or if the receiver has the
initiator encryption certificate on file, it may be used to encrypt
the AS2 message including the EDIINTCertificateExchangeResponse.
Otherwise, it may be necessary to send this
EDIINTCertificateExchangeResponse unencrypted. The message may be
signed, but it is possible the initiator will have no way to verify
the signature. The initiator MUST accept this response, regardless
of if it is signed. A positive MDN received for the response message
indicates successful transmission of the response message.
After the receiver accepts the certificate and returns an acceptance
response, the receiver may encrypt messages to the initiator with the
encryption certificate. The receiver begins to accept messages from
the initiator that are signed with the signing certificate. The
initiator may start signing with the certificate when it receives the
acceptance response, or when it receives acceptance responses from
all its partners, or after the RespondByDate.
4.2.3. Step 3
After the exchange is complete, additional certificates may need to
be exchanged before a complete trading relationship can be
successful. This step is considered an implementation detail that
is left purely to the vendors and users.
5.
Profile Exchange Messaging
CEM provides the means to exchange certificates among trading
partners. However, other profile information, such as URLs and
preferred security settings, is needed to create a trading partner
relationship. A future standard is needed to describe profile
descriptions and how they will be exchanged. The format for this
profile attachment is not defined in this specification but is
planned for a future document. It will build upon the existing CEM
protocol with profile information stored with XML data. Both
certificate and profile description information will be placed into a
multipart/related [RFC2387] body part entity. A possible format for a
profile description message is as follows:
Various EDIINT headers
Disposition-Notification-To: http://10.1.1.1:80/exchange/as2_company
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Disposition-Notification-Options: signed-receipt-protocol=optional,
pkcs7-signature; signed-receipt-micalg=optional, sha1
Content-Type: multipart/signed; micalg=sha1;
protocol="application/pkcs7-signature"; boundary="--BOUNDARY1"
----BOUNDARY1
Content-Type: multipart/related;
start=<aayxdfl01012000 <at> foo.com>";
type=application/ediint-cert-exchange+xml;
boundary="--BOUNDARY2"
----BOUNDARY2
Content-Type: application/ediint-cert-exchange+xml
Content-ID: <aayxdfl01012000 <at> foo.com>
[CEM XML data]
----BOUNDARY2
[Profile information attachment]
----BOUNDARY2--
----BOUNDARY1
Content-Type: application/pkcs7-signature
[Digital Signature]
----BOUNDARY1--
6.
Security Considerations
Certificate exchange is safe for transmitting. However, implementers
SHOULD verify the received certificate to determine if it is truly
from the stated originator through out-of-band means for the initial
use case of 4.2 or whenever the request is not signed.
7.
IANA Considerations
MIME Media type name: Application
MIME subtype name: EDIINT-cert-exchange+xml
Required parameters: None
Optional parameters: 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.
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Security considerations: See section 6.
Interoperability Considerations: See section 2.2
Published specification: This document.
Applications which use this media type: EDIINT applications, such as
AS1, AS2 and AS3 implementations.
Additional Information: None
Intended Usage: Common
Author/Change controller: See Authors section of this document.
8.
References
8.1
Normative References
[AS1] RFC3335 MIME-based Secure Peer-to-Peer Business Data
Interchange over the Internet using SMTP, T. Harding, R.
Drummond, C. Shih, 2002.
[AS2] draft-ietf-ediint-as2-15.txt MIME-based Secure Peer-to-Peer
Business Data Interchange over the Internet using HTTP, D.
Moberg, R. Drummond, 2004.
[AS3] draft-ietf-ediint-as3-02.txt MIME-based Secure Peer-to-Peer
Business Data Interchange over the Internet using FTP, T.
Harding, R. Scott, 2003.
[RFC2119] RFC2119 Key Words for Use in RFC's to Indicate Requirement
Levels, S.Bradner, March 1997.
[RFC2246] RFC2246 "The TLS Protocol", Dierks, T. and C. Allen,
January 1999.
[RFC2387] RFC2387 "The MIME Multipart/Related Content-type", E.
Levinson, August 1998.
[RFC2818] RFC2818 "HTTP over TLS", Rescorla, E., May 2000.
[RFC2828] RFC2828 Internet Security Glossary, R. Shirley, May 2000.
[RFC3023] RFC3023 XML Media Types, M. Murata, January 2001.
[3821] RFC3821 S/MIME Version 3.1 Message Specification, B.
Ramsdell, July 2004.
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[XML-DSIG] RFC3275 XML-Signature Syntax and Processing, D.
Eastlake, March 2002.
[X.520] ITU-T Recommendation X.520: Information Technology Open
Systems Interconnection - The Directory: Selected Attribute
Types, 1993.
[PROFILE] Housley, R., Polk, W., Ford, W. and D. Solo, "Internet
X.509 Public Key Infrastructure: Certificate and CRL Profile",
RFC 3280, April 2002.
8.2
Informative References
9.
Acknowledgments
The authors wish to extend gratitude to the ecGIF sub-committee
within the EAN.UCC organization from which this effort began. Of
special note is John Duker who chaired the sub-committee and provided
valuable editing, Richard Bigelow who greatly assisted development of
the ideas presented, John Koehring with his insights on
implementation and James Zwyer for his contribution to the use case
scenarios.
Author's Addresses
Kyle Meadors
Drummond Group Inc.
4700 Bryant Irvin Court, Suite 303
Fort Worth, TX 76107 USA
Email: kyle <at> drummondgroup.com
Dale Moberg
Cyclone Commerce
8388 E. Hartford Drive, Suite 100
Scottsdale, AZ 85255 USA
Email: dmoberg <at> cyclonecommerce.com
Copyright Notice
Copyright (C) The Internet Society 2004. 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
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WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Appendix
A.1 EDIINT Certificate Exchange XML Schema
<?xml version="1.0" encoding="UTF-8"?>
<!--W3C Schema generated by XMLSPY v2004 rel. 3 U
(http://www.xmlspy.com)-->
<xs:schema
targetNamespace="http://www.ietf.org/schemas/EDIINTCertificateExchang
e.xsd"
xmlns:tns="http://www.ietf.org/schemas/EDIINTCertificateExchange.xsd"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
elementFormDefault="qualified">
<xs:import namespace="http://www.w3.org/2000/09/xmldsig#"
schemaLocation="xmldsig-core-schema.xsd"/>
<xs:element name="EDIINTCertificateExchangeRequest">
<xs:complexType>
<xs:sequence>
<xs:element ref="tns:TradingPartnerInfo"/>
<xs:element name="TrustRequest"
type="tns:TrustRequestType" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="EDIINTCertificateExchangeResponse">
<xs:complexType>
<xs:sequence>
<xs:element ref="tns:TradingPartnerInfo"/>
<xs:element name="TrustResponse"
type="tns:TrustResponseType" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="TradingPartnerInfo">
<xs:complexType>
<xs:sequence>
<xs:element name="Name">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="qualifier"
type="xs:string" use="optional"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
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<xs:element name="MessageOriginated" type="xs:dateTime"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="CertUsage" type="tns:CertUsageType"/>
<xs:simpleType name="CertUsageType">
<xs:restriction base="xs:string">
<xs:enumeration value="tlsClient"/>
<xs:enumeration value="tlsServer"/>
<xs:enumeration value="keyEncipherment"/>
<xs:enumeration value="digitalSignature"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="CertStatus" type="tns:CertStatusType"/>
<xs:simpleType name="CertStatusType">
<xs:restriction base="xs:string">
<xs:enumeration value="Rejected"/>
<xs:enumeration value="Accepted"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="ReasonForRejection" type="xs:string"/>
<xs:element name="RespondByDate" type="xs:dateTime"/>
<xs:element name="ResponseURL" type="xs:anyURI"/>
<xs:complexType name="EndEntityType">
<xs:sequence>
<xs:element name="CertificateIdentifier"
type="ds:X509IssuerSerialType"/>
<xs:element name="CertificateContentID" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="TrustRequestType">
<xs:sequence>
<xs:element ref="tns:CertUsage" maxOccurs="unbounded"/>
<xs:element ref="tns:RespondByDate"/>
<xs:element ref="tns:ResponseURL"/>
<xs:element name="EndEntity" type="tns:EndEntityType"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="TrustResponseType">
<xs:sequence>
<xs:element ref="tns:CertStatus"/>
<xs:element ref="tns:ReasonForRejection" minOccurs="0"/>
<xs:element name="CertificateReference"
type="ds:X509IssuerSerialType"/>
</xs:sequence>
</xs:complexType>
</xs:schema>
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A.2 Example of EDIINT Certificate Exchange Request XML
<?xml version="1.0" standalone="yes"?>
<EDIINTCertificateExchangeRequest
xmlns="EDIINTCertificateExchange.xsd"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.ietf.org/schemas/EDIINTCertificateE
xchange.xsd
EDIINTCertificateExchange.xsd">
<TradingPartnerInfo>
<Name qualifier="AS2">DGI_Test_CEM</Name>
<MessageOriginated>2005-01-27T17:21:00-
05:00</MessageOriginated>
</TradingPartnerInfo>
<TrustRequest>
<CertUsage>keyEncipherment</CertUsage>
<CertUsage>digitalSignature</CertUsage>
<RespondByDate>2005-02-01T12:00:00-05:00</RespondByDate>
<ResponseURL>http://10.1.1.1/as2</ResponseURL>
<EndEntity>
<CertificateIdentifier>
<ds:X509IssuerName>CN=Cleo-SP;
E=as2selfpacedsupport <at> drummondgroup.com;
O=DGI; OU=DGI; L=Ft. Worth; S=Texas;
C=US</ds:X509IssuerName>
<ds:X509SerialNumber>9659684611094873474886</ds:X509SerialNumber>
</CertificateIdentifier>
<CertificateContentID>sign_enc-cert-
012705 <at> example.org</CertificateContentID>
</EndEntity>
</TrustRequest>
<TrustRequest>
<CertUsage>tlsServer</CertUsage>
<RespondByDate>2005-02-01T12:00:00-05:00</RespondByDate>
<ResponseURL>http://10.1.1.1/as2</ResponseURL>
<EndEntity>
<CertificateIdentifier>
<ds:X509IssuerName>CN=VeriSign Class 1 CA Individual
Subscriber-Persona Not Validated;
OU=www.verisign.com/repository/RPA Incorp. By
Ref.,LIAB.LTD(c)98 OU=VeriSign Trust Network
O=VeriSign, Inc.</ds:X509IssuerName>
<ds:X509SerialNumber>2673611014597817669550861744279966682</ds:X509Se
rialNumber>
</CertificateIdentifier>
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<CertificateContentID>ssl-cert-
012705 <at> example.org</CertificateContentID>
</EndEntity>
</TrustRequest>
</EDIINTCertificateExchangeRequest>
A.3 Example of EDIINT Certificate Exchange Response XML
<?xml version="1.0"?>
<EDIINTCertificateExchangeResponse
xmlns="EDIINTCertificateExchange.xsd"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.ietf.org/schemas/EDIINTCertificateExch
ange.xsd EDIINTCertificateExchange.xsd">
<TradingPartnerInfo>
<Name qualifier="AS2">DGI_Test_CEM_Trading_Partner</Name>
<MessageOriginated>2005-01-22T17:21:00-
05:00</MessageOriginated>
</TradingPartnerInfo>
<TrustResponse>
<CertStatus>Accepted</CertStatus>
<CertificateReference>
<ds:X509IssuerName>CN=Cleo-SP;
E=as2selfpacedsupport <at> drummondgroup.com;
O=DGI; OU=DGI; L=Ft. Worth; S=Texas;
C=US</ds:X509IssuerName>
<ds:X509SerialNumber>9659684611094873474886</ds:X509SerialNumber>
</CertificateReference>
</TrustResponse>
<TrustResponse>
<CertStatus>Accepted</CertStatus>
<CertificateReference>
<ds:X509IssuerName>CN=VeriSign Class 1 CA Individual
Subscriber-Persona Not Validated;
OU=www.verisign.com/repository/RPA Incorp. By
Ref.,LIAB.LTD(c)98 OU=VeriSign Trust Network
O=VeriSign, Inc.</ds:X509IssuerName>
<ds:X509SerialNumber>2673611014597817669550861744279966682</ds:X50
9SerialNumber>
</CertificateReference>
</TrustResponse>
</EDIINTCertificateExchangeResponse>
Changes from Previous Versions
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B.1 Updates from Version 00
. Updated security requirements in section 2.1, specifically in
regards to digital signatures.
. The XML element responseURL is now required. Modified section
3.1 and example messages in appendix accordingly.
. Certificates are exchanged within a full P7C cert chain. Section
2.3 reflects this.
. The XML element TrustChain is not longer necessary since the
entire cert chain is stored. Removed references in schema and
document.
. Added statement in 2.5 that multiple CEM Responses SHOULD NOT be
sent and that if this occurs, the action of the CEM Request
initiator is not defined.
. Updated the examples in Appendix B to reflect the current usage.
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