title: unsupported SignatureMethod algorithm, but the algorithm is listed as available Service by BC-Provider
body: <p>to keep it short, my problem is as follows:</p>
  
  <p>I add the BC-Provider at the beginning of my function:</p>
  
  <pre><code>Security.addProvider(new BouncyCastleProvider());
  </code></pre>
  
  <p>when i List all Services</p>
  
  <pre><code>BouncyCastleProvider().getServices();
  </code></pre>
  
  <p>the List contains
  "RIPEMD160WITHECDSA"</p>
  
  <p>on the last line of this codesnippet: </p>
  
  <pre><code>XMLSignatureFactory factory = XMLSignatureFactory.getInstance("DOM");
  DOMValidateContext valContext = new DOMValidateContext(pubkeys[i], sigElement);
  valContext.setURIDereferencer(new FileDereferencer(
                                factory.getURIDereferencer(), new File("D:\\eclipseworkspace\\pathtoxml.xml")));
  javax.xml.crypto.dsig.XMLSignature xmlSignature = factory.unmarshalXMLSignature(valContext);
  </code></pre>
  
  <p>i get an Exception with the Message:</p>
  
  <p>unsupported SignatureMethod algorithm: <a href="http://www.w3.org/2007/05/xmldsig-more#ecdsa-ripemd160" rel="nofollow">http://www.w3.org/2007/05/xmldsig-more#ecdsa-ripemd160</a></p>
  
  <p>What does that mean? what is the difference between RIPEMD160WITHECDSA und the Algorithm specified by this URL?
  Or is the url just not mapped to this Algorithmname?</p>
  
  <p>Here is the stacktrace:</p>
  
  <pre><code>javax.xml.crypto.MarshalException: unsupported SignatureMethod algorithm: http://www.w3.org/2007/05/xmldsig-more#ecdsa-ripemd160
      at org.jcp.xml.dsig.internal.dom.DOMSignatureMethod.unmarshal(Unknown Source)
      at org.jcp.xml.dsig.internal.dom.DOMSignedInfo.&lt;init&gt;(Unknown Source)
      at org.jcp.xml.dsig.internal.dom.DOMXMLSignature.&lt;init&gt;(Unknown Source)
      at org.jcp.xml.dsig.internal.dom.DOMXMLSignatureFactory.unmarshal(Unknown Source)
      at org.jcp.xml.dsig.internal.dom.DOMXMLSignatureFactory.unmarshalXMLSignature(Unknown Source)
      at com.mobile.xmlsignature.XMLSigChecker.verify(XMLSigChecker.java:122)
      at com.mobile.xmlsignature.mainclass.main(mainclass.java:13)
  </code></pre>