Issue with RSA signing in IBM DataPower

I am unable to generate specific sections of SAML assertions in IBM DataPower while trying to digitally sign a request (Product details: Build: 277257, Firmware: IDG.7.5.1.0). I have the uploaded the public crypto certificate on DataPower but I am unable to configure DataPower to generate the following two sections (The below is the format in which the backend expects the DataPower output):

1.

<ds:KeyInfo>
  <ds:KeyValue>
    <ds:RSAKeyValue>
      <ds:Modulus>xxx</ds:Modulus>
      <ds:Exponent>xxx</ds:Exponent>
    </ds:RSAKeyValue>
  </ds:KeyValue>
</ds:KeyInfo>

2.

<ds:KeyInfo Id="KeyId-xxx">
  <wsse:SecurityTokenReference wsse11:TokenType="http://docs.oasis-open.org/wss/oasis-wss-saml-token-profile-1.1#SAMLV2.0" wsu:Id="xxx" xmlns:wsse11="http://docs.oasis-open.org/wss/oasis-wss-wssecurity-secext-1.1.xsd">
    <wsse:KeyIdentifier ValueType="http://docs.oasis-open.org/wss/oasis-wss-saml-token-profile-1.1#SAMLID">xxx</wsse:KeyIdentifier>
  </wsse:SecurityTokenReference>
</ds:KeyInfo>

Are there any settings on DataPower to generate these header? Or we need to place a custom XSL transform to generate these headers?