"final" RetrievalMethod

<h3>4.4.3 The <a id="sec-RetrievalMethod"

<p>A <code>RetrievalMethod</code> element within <code>KeyInfo</code>
is used to convey a <u>reference</u> to <code>KeyInfo</code>
information that is stored at <u>another</u> location. For example,
<u>several sigantures in a document might use a key verified by</u> an
X.509v3 certificate chain <u>appearing once in the document or
remotely outside the document</u>; each <u>signature's
<code>KeyInfo</code></u> can reference this chain using a single
<code>RetrievalMethod</code> element instead of including the entire
chain with a sequence of <code>X509Certificate</code> elements.</p>

<p><u><code>RetrievalMethod</code> uses the same syntax as
<code>Reference</code> except that there is no
<code>DigestMethod</code> or <code>DigestValue</code> sub-element and
presence of the <code>URI</code> and <code>Type</code> attributes is
mandatory.  The referenced data is a <code>KeyInfo</code> sub-element
type.  The <code>Type</code> attribute, as in Section 4.3.3, is a URI
consisting of "http://www.w3.org/2000/07/xmldsig#" suffixed with a
<code>KeyInfo</code> sub-element type, such as

<pre class="xml-dtd">
   Schema Definition:

   &lt;element name='RetrievalMethod'&gt; 
     &lt;complexType content='elementOnly'&gt;
       &lt;element ref='ds:Transforms' minOccurs='0' maxOccurs='1'/&gt; 
       &lt;attribute name='URI' type='uriReference'/&gt; 
       &lt;attribute name='Type' type='uriReference'/&gt; 

<pre class="xml-dtd">

   &lt;!ELEMENT RetrievalMethod (Transforms?) &gt;
   &lt;!ATTLIST Type 
             URI       CDATA   #REQUIRED
             Encoding  CDATA   #REQUIRED &gt;

Received on Friday, 25 August 2000 16:23:39 UTC