<html>
  <head>
    <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    Seems to me you want to add the URI needed to initiate the WebID
    authentication protocol to HTTP requests. Why don't you just create
    a WebID-specific header (e.g. "webid") or a WebID-specific
    authorization scheme? Or is it imagined to initiate a OpenID process
    as well?<br>
    <br>
    regards,<br>
    Torsten.<br>
    <br>
    <div class="moz-cite-prefix">Am 19.07.2013 17:45, schrieb Kingsley
      Idehen:<br>
    </div>
    <blockquote cite="mid:51E95F17.5000203@openlinksw.com" type="cite">
      <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
      <div class="moz-cite-prefix">On 7/19/13 11:10 AM, Torsten
        Lodderstedt wrote:<br>
      </div>
      <blockquote
        cite="mid:D671F542-FF0B-4FC9-99AC-37F09E0A01D1@lodderstedt.net"
        type="cite">
        <div>Hi Kingsley,</div>
        <div><br>
        </div>
        <div>so your are essentially saying, the user agent (or a
          similar application) sets a URL, which the server uses in turn
          to obtain some values. </div>
      </blockquote>
      <br>
      To be precise, an end-user would (via UI/UX) have the *option* to
      provide a URI that's added to the HTTP payload via an HTTP client
      (e.g., a Browser or other User Agents). <br>
      <br>
      <blockquote
        cite="mid:D671F542-FF0B-4FC9-99AC-37F09E0A01D1@lodderstedt.net"
        type="cite">
        <div>These values are used to meet access control decisions. Did
          I get this right?</div>
      </blockquote>
      <br>
      The header values would then be incorporated into a mechanism for
      protected resource access control and anything else that benefits
      from verifiable identity. <br>
      <br>
      <blockquote
        cite="mid:D671F542-FF0B-4FC9-99AC-37F09E0A01D1@lodderstedt.net"
        type="cite">
        <div><br>
        </div>
        <div>How does the server ensure the caller is the user
          represented by this URL? </div>
      </blockquote>
      <br>
      Through the logic of "shared secrets" and "mirrored claims" . This
      is just about the ability to make an verify claims based on logic.
      <br>
      <br>
      <blockquote
        cite="mid:D671F542-FF0B-4FC9-99AC-37F09E0A01D1@lodderstedt.net"
        type="cite">
        <div>So for example, how would you prevent an attacker from
          sending your user id URL to the server (and in turn
          impersonating you on this server)?</div>
      </blockquote>
      <br>
      The server would verify identity based on logic. For instance, it
      can verify that the user agent is being driven by an entity that
      has access to:<br>
      <br>
      1. private key which was used to make a signature -- stored
      locally and accessed via native OS UI/UX controls (e.g., Keychain
      on Mac OS X)<br>
      2. certificate bearing claims that are mirrored in the document to
      which the URI resolves<br>
      3. any other relationship that the data access policy deems worthy
      .<br>
      <br>
      Note, this already works. We are just seeking to simplify
      exploitation entry points. <br>
      <br>
      Links:<br>
      <br>
      1. <a moz-do-not-send="true" class="moz-txt-link-freetext"
        href="http://bit.ly/UuWZSI">http://bit.ly/UuWZSI</a> -- various
      posts about this matter<br>
      2. <a moz-do-not-send="true" class="moz-txt-link-freetext"
        href="http://bit.ly/UDlwc6">http://bit.ly/UDlwc6</a> --
      multi-identifier and multi-protocol based identity verification.<br>
      <br>
      Kingsley
      <blockquote
        cite="mid:D671F542-FF0B-4FC9-99AC-37F09E0A01D1@lodderstedt.net"
        type="cite">
        <div><br>
          Am 19.07.2013 um 15:42 schrieb Kingsley Idehen <<a
            moz-do-not-send="true" href="mailto:kidehen@openlinksw.com">kidehen@openlinksw.com</a>>:<br>
          <br>
        </div>
        <blockquote type="cite">
          <div>
            <meta content="text/html; charset=UTF-8"
              http-equiv="Content-Type">
            <div class="moz-cite-prefix">On 7/19/13 4:14 AM, Torsten
              Lodderstedt wrote:<br>
            </div>
            <blockquote
              cite="mid:58653cc8-cb68-4d29-9460-8c3d9c7f71d4@email.android.com"
              type="cite">
              <meta content="text/html; charset=UTF-8"
                http-equiv="Content-Type">
              <meta content="text/html; charset=UTF-8"
                http-equiv="Content-Type">
              Hi,<br>
              <br>
              could you please shed some light on the use case for the
              User field? What entity sets the value, what entitity uses
              it for what purpose? <br>
            </blockquote>
            <br>
            It holds a URI that resolves to a document bearing content
            that describes the URIs referent. For example, this document
            could be comprised of a machine-readable
            entity->attribute->value  or
            subject->predicate->object based relations. <br>
            <br>
            An end-user application (including browser extensions or
            plugins) will set the value. A server will make use of these
            values e.g., looking up the URIs to locate the description
            of the entity denoted (named) by the URI. It can then use
            this description as the basis for ACLs and sophisticated
            data access policies which are all driven by logic. <br>
            <br>
            <br>
            Kingsley <br>
            <blockquote
              cite="mid:58653cc8-cb68-4d29-9460-8c3d9c7f71d4@email.android.com"
              type="cite"> <br>
              Regards,<br>
              Torsten.<br>
              <br>
              <div class="gmail_quote"><br>
                <br>
                Kingsley Idehen <a moz-do-not-send="true"
                  class="moz-txt-link-rfc2396E"
                  href="mailto:kidehen@openlinksw.com"><kidehen@openlinksw.com></a>
                schrieb:
                <blockquote class="gmail_quote" style="margin: 0pt 0pt
                  0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204);
                  padding-left: 1ex;">
                  <div class="moz-cite-prefix">On 7/18/13 1:38 PM,
                    Torsten Lodderstedt wrote:<br>
                  </div>
                  <blockquote
                    cite="mid:79cf3a27-c0d1-43e1-b1e6-6442e1d2c13c@email.android.com"
                    type="cite"> I fully agree with George und would
                    like to add: why don't you just use the
                    authorization header to send identity
                    data/credentials/tokens to the server in order to
                    allow for access control?<br>
                  </blockquote>
                  <br>
                  This is already possible. The requirement here stems
                  from the fact that "From:" is bound specifically to
                  mailto: scheme URIs (Uniform Resource Identifiers). We
                  are looking to "User:" to be the superClass of "From:"
                  which is basically URI scheme agnostic. That's it. <br>
                  <br>
                  [SNIP]<br>
                  <pre class="moz-signature" cols="72">-- 

Regards,

Kingsley Idehen       
Founder & CEO 
OpenLink Software     
Company Web: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com">http://www.openlinksw.com</a>
Personal Weblog: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com/blog/%7Ekidehen">http://www.openlinksw.com/blog/~kidehen</a>
Twitter/<a moz-do-not-send="true" href="http://Identi.ca">Identi.ca</a> handle: @kidehen
Google+ Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://plus.google.com/112399767740508618350/about">https://plus.google.com/112399767740508618350/about</a>
LinkedIn Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.linkedin.com/in/kidehen">http://www.linkedin.com/in/kidehen</a>




</pre>
                </blockquote>
              </div>
            </blockquote>
            <br>
            <br>
            <pre class="moz-signature" cols="72">-- 

Regards,

Kingsley Idehen       
Founder & CEO 
OpenLink Software     
Company Web: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com">http://www.openlinksw.com</a>
Personal Weblog: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com/blog/%7Ekidehen">http://www.openlinksw.com/blog/~kidehen</a>
Twitter/<a moz-do-not-send="true" href="http://Identi.ca">Identi.ca</a> handle: @kidehen
Google+ Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://plus.google.com/112399767740508618350/about">https://plus.google.com/112399767740508618350/about</a>
LinkedIn Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.linkedin.com/in/kidehen">http://www.linkedin.com/in/kidehen</a>




</pre>
          </div>
        </blockquote>
      </blockquote>
      <br>
      <br>
      <pre class="moz-signature" cols="72">-- 

Regards,

Kingsley Idehen       
Founder & CEO 
OpenLink Software     
Company Web: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com">http://www.openlinksw.com</a>
Personal Weblog: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.openlinksw.com/blog/%7Ekidehen">http://www.openlinksw.com/blog/~kidehen</a>
Twitter/Identi.ca handle: @kidehen
Google+ Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://plus.google.com/112399767740508618350/about">https://plus.google.com/112399767740508618350/about</a>
LinkedIn Profile: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.linkedin.com/in/kidehen">http://www.linkedin.com/in/kidehen</a>




</pre>
    </blockquote>
    <br>
  </body>
</html>