Xml Digital signature with C# .NET Core 1.1

Question

I am working on a client side communication with a SOAP web services using .NET Core (latest version at the moment 1.1.) and C# (actually Omnisharp). Requests should be digitally signed with an enveloped signature, using RSA-SHA1 signing method, ending up with structure like this:

<soap:Envelope> 
  <soap:Body> 
    <MyRootElement>
      <MyData>
          ...
      </MyData> 
     <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
       <SignedInfo>
         <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
         <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
         <Reference URI="#G0xcabf5080-4D">
           <Transforms>
             <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
             <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
           </Transforms>
           <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
           <DigestValue>4j9JKFMvg6Mmfx7ERu8R3WkZTtQ=</DigestValue>
         </Reference>
       </SignedInfo>
       <SignatureValue>....</SignatureValue>
       <KeyInfo>
         <X509Data>
           <X509Certificate>....</X509Certificate> 
           <X509IssuerSerial>
             <X509IssuerName>...</X509IssuerName>
             <X509SerialNumber>72672627</X509SerialNumber>
           </X509IssuerSerial>
         </X509Data>
       </KeyInfo>
     </Signature>
   </MyRootElement>
  </soap:Body>
</soap:Envelope>

All documentation I was able to find refer to using SignedXml class that is not available in .NET Core. Does anyone have suggestion or link to share how can I make this signature (and required canonicalization) without SignedXml class? Or maybe there is some unofficial version of SignedXml that I am not aware of?

Answer 1

SignedXml is in the tree at https://github.com/dotnet/corefx and presumably will be available with the upcoming 2.0 release (as a nuget package, not the shared framework bundle).

It has a lot of dependencies on 2.0 types, so it would be difficult to try to port it back to 1.1; but maybe you could carve it down to your specific needs.

Or, try with the 2.0 preview release and see if things just work.