Signing root node without childs

[alphanso]

Hi,

I am trying to sign a root node with only attributes and without any child nodes. It keeps failing signature verification but if I add a single space then it works. Is it an issue with library or my code. Please help me debug.

var SignedXml = require('xml-crypto').SignedXml
      , fs = require('fs')
      , dom = require('xmldom').DOMParser
      , select = require('xml-crypto').xpath
      , FileKeyInfo = require('xml-crypto').FileKeyInfo;

function main() {
  var xml = '<?xml version="1.0" encoding="UTF-8"?><library> </library>'
  var myXML = '<?xml version="1.0" encoding="UTF-8"?><library></library>'

  sign(xml, "library");
  console.log("\n\n\n\n");
  sign(myXML, "library");
}

function sign (xml) {
  var sig = new SignedXml()
  sig.addReference("/*", ["http://www.w3.org/2000/09/xmldsig#enveloped-signature"], "http://www.w3.org/2000/09/xmldsig#sha1", "", "", "", true);
  sig.signingKey = fs.readFileSync("./private.pem")
  sig.computeSignature(xml)
  var signed = sig.getSignatureXml()
  var withIds = sig.getOriginalXmlWithIds()
  console.log(signed)
  console.log(withIds)
  console.log(sig.getSignedXml())

  verify(signed, withIds);
}

function verify(signed, withIds) {
  var sig = new SignedXml()
  sig.keyInfoProvider = new FileKeyInfo("./public.pem")
  sig.loadSignature(signed)
  var res = sig.checkSignature(withIds)
  console.log(res)
  if (!res) console.log(sig.validationErrors)
  else console.log('Valid Signature')
}

main();

I actually need to encrypt following xml

<?xml version="1.0" encoding="UTF-8"?>
<Node att1="val1" ver="1.0" ts="2017-07-11T21:06:46.128" att2="val2" att3="1dea22d1-f153-4fd2-befa-527ffda2f692"/>

[alphanso]

I have identified the issue
https://github.com/yaronn/xml-crypto/blob/master/lib/enveloped-signature.js#L9

We are using xpath in above given line. Once we remove signature then xpath reduce tag to which is not canonicalized form which leads to problem in xml signature as show above.

[cjbarth]

@alphanso , I'm very glad you found and fixed your issue. To help the community benefit from your efforts, would you consider creating a PR with a test suite and your solution?