添加 c14n 独占转换后，Xml 签名无效

Question

这是我生成 xml 签名的代码：

DOMSignContext dsc = new DOMSignContext
  (prk, xmldoc.getDocumentElement());

XMLSignatureFactory fac = 
  XMLSignatureFactory.getInstance("DOM");   

  DigestMethod digestMethod = 
      fac.newDigestMethod("http://www.w3.org/2000/09/xmldsig#sha1", null);
  C14NMethodParameterSpec spec = null;
  CanonicalizationMethod cm = fac.newCanonicalizationMethod(
      "http://www.w3.org/2001/10/xml-exc-c14n#",spec);
  SignatureMethod sm = fac.newSignatureMethod( 
      "http://www.w3.org/2000/09/xmldsig#rsa-sha1",null);
  ArrayList transformList = new ArrayList();
  TransformParameterSpec transformSpec = null;
  Transform envTransform =   fac.newTransform("http://www.w3.org/2000/09/xmldsig#enveloped-signature",transformSpec);
  Transform exc14nTransform = fac.newTransform(
      "http://www.w3.org/2001/10/xml-exc-c14n#",transformSpec);
transformList.add(exc14nTransform); 
transformList.add(envTransform);

 Reference ref = fac.newReference("",digestMethod,transformList,null,null);
 ArrayList refList = new ArrayList();
 refList.add(ref);
 SignedInfo si =fac.newSignedInfo(cm,sm,refList);

这使得参考验证为假，并且核心有效性为假。但是当我删除 envTrasnform 变量即 fac.new Transform("http://www.w3.org/2001/10/xml-exc-c14n#",transformSpec) 并使用以下代码执行：

DOMSignContext dsc = new DOMSignContext
  (prk, xmldoc.getDocumentElement());

XMLSignatureFactory fac = 
  XMLSignatureFactory.getInstance("DOM");   

  DigestMethod digestMethod = 
      fac.newDigestMethod("http://www.w3.org/2000/09/xmldsig#sha1", null);
  C14NMethodParameterSpec spec = null;
  CanonicalizationMethod cm = fac.newCanonicalizationMethod(
      "http://www.w3.org/2001/10/xml-exc-c14n#",spec);
  SignatureMethod sm = fac.newSignatureMethod( 
      "http://www.w3.org/2000/09/xmldsig#rsa-sha1",null);
  ArrayList transformList = new ArrayList();
  TransformParameterSpec transformSpec = null;
  Transform envTransform = fac.newTransform(
      "http://www.w3.org/2000/09/xmldsig#enveloped-signature",transformSpec);
 transformList.add(envTransform);
 Reference ref = fac.newReference("",digestMethod,transformList,null,null);
 ArrayList refList = new ArrayList();
 refList.add(ref);
 SignedInfo si =fac.newSignedInfo(cm,sm,refList);

这使得核心效度和参考效度为真。为什么会出现这种情况。我得到了这个代码表格 这 链接（创建封装签名部分中的代码片段2）。

Answer 1

实际上，c14n 变换应该在封装签名变换之后执行。提取要签名的文档后应对其进行规范化（该文档当前也包含签名元素。因此，在规范化要签名的实际部分之前必须将其分开）。顺序应该是这样的：

transformList.add(envTransform);
 transformList.add(exc14nTransform);