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<p class="MsoNormal"><span style="color:#1F497D">This is the speclet we’d discussed for a JWK Thumbprint, which is pertinent to the revised “sub” computation needed for issue #920 -
<a href="https://bitbucket.org/openid/connect/issue/920/attack-identified-against-self-issued-sub">
https://bitbucket.org/openid/connect/issue/920/attack-identified-against-self-issued-sub</a>.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> -- Mike<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Mike Jones
<br>
<b>Sent:</b> Thursday, April 10, 2014 5:50 PM<br>
<b>To:</b> jose@ietf.org<br>
<b>Subject:</b> JSON Web Key (JWK) Thumbprint Specification<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I created a new simple spec that defines a way to create a thumbprint of an arbitrary key, based upon its JWK representation. The abstract of the spec is:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-left:.5in"><span lang="EN" style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black">This specification defines a means of computing a thumbprint value (a.k.a. digest) of JSON Web Key (JWK) objects analogous
to the </span><tt><span lang="EN" style="font-size:10.0pt">x5t</span></tt><span lang="EN" style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> (X.509 Certificate SHA-1 Thumbprint) value defined for X.509 certificate objects. This specification
also registers the new JSON Web Signature (JWS) and JSON Web Encryption (JWE) Header Parameters and the new JSON Web Key (JWK) member name
</span><tt><span lang="EN" style="font-size:10.0pt">jkt</span></tt><span lang="EN" style="font-size:10.0pt;font-family:"Verdana","sans-serif";color:black"> (JWK SHA-256 Thumbprint) for holding these values.</span><span style="font-size:10.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The desire for this came up in an OpenID Connect context, but it’s of general applicability, so I decided to submit the spec to the JOSE working group. Thanks to James Manger, John Bradley, and Nat Sakimura for the discussions that led
up to this spec.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The specification is available at:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><a href="http://tools.ietf.org/html/draft-jones-jose-jwk-thumbprint-00">http://tools.ietf.org/html/draft-jones-jose-jwk-thumbprint-00</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">An HTML formatted version is also available at:<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo4"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><a href="https://self-issued.info/docs/draft-jones-jose-jwk-thumbprint-00.html">https://self-issued.info/docs/draft-jones-jose-jwk-thumbprint-00.html</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> -- Mike<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">P.S. I also posted this notice at <a href="http://self-issued.info/?p=1213">
http://self-issued.info/?p=1213</a> and as @selfissued.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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