public bool VerifyXmlFile(XmlDocument xmlDocument)
{
if (xmlDocument == null)
{
throw new ArgumentException($"{nameof(xmlDocument)} cannot be null. Please supply a valid xml document");
}
var signedXml = new CustomIdSignedXml(xmlDocument);
var nodeList = xmlDocument.GetElementsByTagName(SignatureElementName, NS2);
var xmlDigitalSignature = (XmlElement)nodeList[0];
if (xmlDigitalSignature == null)
{
return(true);
}
signedXml.LoadXml(xmlDigitalSignature);
// Check the signature and return the result.
return(signedXml.CheckSignature());
}
public void Hack()
{
XmlDocument doc = new XmlDocument();
doc.PreserveWhitespace = true;
doc.Load(@"C:\TMP\cache.xml");
SignedXml sig = new CustomIdSignedXml(doc);
XmlNodeList nodeList = doc.GetElementsByTagName("Signature", "http://www.w3.org/2000/09/xmldsig#");
foreach (XmlElement e in nodeList)
{
sig.LoadXml(e);
Assert.IsTrue(sig.CheckSignature());
}
}
public string SignXmlFile(XmlDocument xmlDocument, X509Certificate2 certificate, string xmlSignatureSyntax)
{
if (xmlDocument == null)
{
throw new ArgumentException($"{nameof(xmlDocument)} cannot be null. Please supply a valid xml document");
}
if (certificate == null)
{
throw new ArgumentException($"{nameof(certificate)} cannot be null. Please supply a valid certificate");
}
if (string.IsNullOrWhiteSpace(xmlSignatureSyntax))
{
throw new ArgumentException($"{nameof(xmlSignatureSyntax)} cannot be null. Please supply a valid XmlSignatureSyntax");
}
// Load xml and set signing parameters
var signedXml = new CustomIdSignedXml(xmlDocument);
signedXml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigC14NTransformUrl;
signedXml.SignedInfo.SignatureMethod = SignatureMethod;
signedXml.SigningKey = certificate.GetRSAPrivateKey();;
// Set the namespases
var nsmgr = new XmlNamespaceManager(xmlDocument.NameTable);
nsmgr.AddNamespace("ns", xmlSignatureSyntax);
nsmgr.AddNamespace("ns2", NS2);
// Select message node for signing
var reference = new Reference();
reference.DigestMethod = DigestMethod;
reference.Uri = "#" + xmlDocument.SelectSingleNode($"//ns:{MessageElementName}", nsmgr)
.Attributes["messageId"].Value;
signedXml.AddReference(reference);
// Set signing key and sign xml data
var keyInfo = new KeyInfo();
keyInfo.AddClause(new KeyInfoX509Data(certificate));
signedXml.KeyInfo = keyInfo;
signedXml.ComputeSignature();
// Get signature
var xmlDigitalSignature = signedXml.GetXml();
// Assign ds prefix
AssignNameSpacePrefixToElementTree(xmlDigitalSignature, CustomPrefix);
//load SignedInfo and compute final signature based on correct SignedInfo
signedXml.LoadXml(xmlDigitalSignature);
signedXml.SignedInfo.References.Clear();
signedXml.ComputeSignature();
// Replace signature
ReplaceSignature(xmlDigitalSignature, Convert.ToBase64String(signedXml.SignatureValue));
// Append signature to the xml doc
xmlDocument.DocumentElement.AppendChild(xmlDocument.ImportNode(xmlDigitalSignature, true));
using var stringWriter = new StringWriter();
using var xmlTextWriter = new XmlTextWriter(stringWriter);
xmlDocument.WriteTo(xmlTextWriter);
xmlTextWriter.Flush();
return(stringWriter.ToString());
}
