We are doing Integration with external systems and unable to calcualte ds:DigestValue and ds:SignatureValue values

<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:v1=".........." xmlns:v11="........">
  <soap:Header xmlns:wsa="http://www.w3.org/2005/08/addressing">
    <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
      <wsu:Timestamp wsu:Id="TS-128F375C5B3256FAE8151780686184254">
        <wsu:Created>2018-02-05T15:07:42Z</wsu:Created>
        <wsu:Expires>2018-02-05T15:12:42Z</wsu:Expires>
      </wsu:Timestamp>
      <wsse:BinarySecurityToken EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary" ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3" wsu:Id="X509-128F375C5B3256FAE8151780686183551"> ----
 --Certificate-</wsse:BinarySecurityToken>
      <ds:Signature Id="SIG-128F375C5B3256FAE8151780686183653" xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
        <ds:SignedInfo>
          <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#">
            <ec:InclusiveNamespaces PrefixList="wsa soap v1 v11" xmlns:ec="http://www.w3.org/2001/10/xml-exc-c14n#"/>
          </ds:CanonicalizationMethod>
          <ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
          <ds:Reference URI="#id-128F375C5B3256FAE8151780686183652">
            <ds:Transforms>
              <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#">
                <ec:InclusiveNamespaces PrefixList="soap v1 v11" xmlns:ec="http://www.w3.org/2001/10/xml-exc-c14n#"/>
              </ds:Transform>
            </ds:Transforms>
            <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
            <ds:DigestValue>--How to calcualte this?--</ds:DigestValue>
          </ds:Reference>
        </ds:SignedInfo>
        <ds:SignatureValue> --How to calcualte this?--</ds:SignatureValue>
        <ds:KeyInfo Id="KI-128F375C5B3256FAE8151780686183550">
          <wsse:SecurityTokenReference wsu:Id="STR-128F375C5B3256FAE8151780686183551">
            <wsse:Reference URI="#X509-128F375C5B3256FAE8151780686183549" ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3"/>
          </wsse:SecurityTokenReference>
        </ds:KeyInfo>
      </ds:Signature>
    </wsse:Security>
    
  </soap:Header>

Please let me know how to get ds:DigestValue, ds:SignatureValue values and in which order we have to calculate.