RE: making a decision on CEM

"Richard Bigelow" <[email protected]> Mon, 13 Feb 2006 12:34:21 -0800
Newsgroups gmane.ietf.ediint
Message-ID <[email protected]>
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In CEM, I suggest distinguishing between the protocol for certificate
exchange and the specific CEM message structure and protocols.  In CEM
draft 2 of 8/8/05, section 2.4 Certificate Implementation describes
requirements on the initiator and recipient of CEM messages.  Paragraphs
2-4 say (<>s added)

=20

<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.

=20

<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 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.

=20

<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.

=20

These requirements (particularly the parts in red and <>s above) can
apply to any certificate exchange protocol, not just to CEM.  That is,
regardless of how the certificates are exchanged, the same requirements
apply to when the certificates are put in use and to acceptance of both
old and new certificates.  There is value in describing these exchange
requirements as a protocol, distinct from the CEM message structure and
request/response protocol.  CEM is then an implementation of the
exchange protocol.  Describing the exchange protocol separately might be
valuable to people who use certificates in non-ASn protocols or who do
not yet have or do not want to use CEM.  (For instance, one company has
an elaborate procedure for coordinating changes at both systems so both
sides change certificates at the same time.  This should not be
necessary.  I want to lead people away from such procedures, even if
they retain manual methods.  CEM would go further and allow automated
implementations of the exchange protocol.)

=20

Richard Bigelow
Inovis
[email protected] <mailto:[email protected]>=20


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<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>In CEM, I suggest distinguishing =
between
the protocol for certificate exchange and the specific CEM message =
structure
and protocols.&nbsp; In CEM draft 2 of 8/8/05, section 2.4 Certificate
Implementation describes requirements on the initiator and recipient of =
CEM
messages.&nbsp; Paragraphs 2-4 say (&lt;&gt;s =
added)<o:p></o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DRFCText><font size=3D3 color=3Dred face=3D"Courier New"><span
style=3D'font-size:12.0pt;color:red'>&lt;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.&gt;</span></font>
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.<o:p></o:p></p>

<p class=3DRFCText><font size=3D3 face=3D"Courier New"><span =
style=3D'font-size:12.0pt'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DRFCText><font size=3D3 color=3Dred face=3D"Courier New"><span
style=3D'font-size:12.0pt;color:red'>&lt;When a certificate is intended =
for use
in digital signatures or TLS/SSL client authentication, the initiator =
MUST NOT
use the certificate until&gt;</span></font> the recipient trading =
partner
generates a CEM Response accepting the certificate or <font =
color=3Dred><span
style=3D'color:red'>&lt;the respond by date&gt;</span></font>, which is =
listed in
the RespondByDate XML element. The initiator MAY use the 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.<o:p></o:p></p>

<p class=3DRFCText><font size=3D3 face=3D"Courier New"><span =
style=3D'font-size:12.0pt'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DRFCText><font size=3D3 color=3Dred face=3D"Courier New"><span
style=3D'font-size:12.0pt;color:red'>&lt;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.&gt; =
</span></font>Revoking
a certificate MUST be done outside of CEM.<o:p></o:p></p>

<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>These requirements (particularly =
the parts
in red and &lt;&gt;s above) can apply to any certificate exchange =
protocol, not
just to CEM.&nbsp; That is, regardless of how the certificates are =
exchanged,
the same requirements apply to when the certificates are put in use and =
to
acceptance of both old and new certificates.&nbsp; There is value in =
describing
these exchange requirements as a protocol, distinct from the CEM message
structure and request/response protocol.&nbsp; CEM is then an =
implementation of
the exchange protocol.&nbsp; Describing the exchange protocol separately =
might
be valuable to people who use certificates in non-ASn protocols or who =
do not yet
have or do not want to use CEM.&nbsp; (For instance, one company has an
elaborate procedure for coordinating changes at both systems so both =
sides
change certificates at the same time.&nbsp; This should not be =
necessary.&nbsp;
I want to lead people away from such procedures, even if they retain =
manual
methods.&nbsp; CEM would go further and allow automated implementations =
of the exchange
protocol.)<o:p></o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p>&nbsp;</o:p></span></font></p>

<div>

<p class=3DMsoNormal><font size=3D3 color=3Dnavy face=3D"Times New =
Roman"><span
style=3D'font-size:12.0pt;color:navy'>Richard Bigelow<br>
</span></font><ns0:Street w:insAuthor=3D"IPNet" =
w:insDate=3D"2006-02-13T11:49:00Z"
 w:endInsAuthor=3D"IPNet" =
w:endInsDate=3D"2006-02-13T11:49:00Z"><ns0:address
  w:insAuthor=3D"IPNet" w:insDate=3D"2006-02-13T11:49:00Z" =
w:endInsAuthor=3D"IPNet"
  w:endInsDate=3D"2006-02-13T11:49:00Z"><font color=3Dnavy><span =
style=3D'color:navy'>Inovis</span></font></ns0:address></ns0:Street><ns0:=
Street
 w:insAuthor=3D"IPNet" w:insDate=3D"2006-02-13T11:49:00Z" =
w:endInsAuthor=3D"IPNet"
 w:endInsDate=3D"2006-02-13T11:49:00Z"><ns0:address =
w:insAuthor=3D"IPNet"
  w:insDate=3D"2006-02-13T11:49:00Z" w:endInsAuthor=3D"IPNet"
  w:endInsDate=3D"2006-02-13T11:49:00Z"><font color=3Dnavy><span =
style=3D'color:navy'><br>
  </span></font></ns0:address></ns0:Street><font color=3Dnavy><span
style=3D'color:navy'><a href=3D"mailto:[email protected]"><font =
size=3D1
face=3DVerdana><span =
style=3D'font-size:9.0pt;font-family:Verdana'>[email protected]<=
/span></font></a></span></font><o:p></o:p></p>

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No virus found in this outgoing message.<BR>
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Version: 7.1.375 / Virus Database: 267.15.4/255 - Release Date: =
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