/// <summary>
/// Check the signature of the specified signed document (created with CreateSignedDoc) using the specified public key.
/// </summary>
/// <param name="signedDoc"></param>
/// <param name="keyPub">Public key</param>
/// <returns></returns>
public static bool CheckSignature(System.Xml.XmlDocument signedDoc, string keyPub)
{
System.Security.Cryptography.RSACryptoServiceProvider rsa = new System.Security.Cryptography.RSACryptoServiceProvider();
rsa.FromXmlString(keyPub);
// Create a new SignedXml object and pass it
// the XML document class.
System.Security.Cryptography.Xml.SignedXml sx = new System.Security.Cryptography.Xml.SignedXml(signedDoc);
// Load the first <signature> node.
sx.LoadXml(GetSignatureFromSignedDoc(signedDoc));
// Check the signature and return the result.
return(sx.CheckSignature(rsa));
}
// Verify the signature of an XML file against an asymmetric
// algorithm and return the result.
private Boolean VerifyXml(XmlDocument Doc, RSA Key)
{
// Check arguments.
if (Doc == null)
{
throw new ArgumentException("Doc");
}
if (Key == null)
{
throw new ArgumentException("Key");
}
// Create a new SignedXml object and pass it
// the XML document class.
var signedXml = new System.Security.Cryptography.Xml.SignedXml(Doc);
// Find the "Signature" node and create a new XmlNodeList object.
XmlNodeList nodeList = Doc.GetElementsByTagName("Signature");
// Throw an exception if no signature was found.
if (nodeList.Count <= 0)
{
throw new CryptographicException("Verification failed: No Signature was found in the document.");
}
// Though it is possible to have multiple signatures on
// an XML document, this app only supports one signature for
// the entire XML document. Throw an exception
// if more than one signature was found.
if (nodeList.Count >= 2)
{
throw new CryptographicException("Verification failed: More that one signature was found for the document.");
}
// Load the first <signature> node.
signedXml.LoadXml((XmlElement)nodeList[0]);
// Check the signature and return the result.
return(signedXml.CheckSignature(Key));
}
/// <summary>
/// Check the signature of the specified signed document (created with CreateSignedDoc) using the specified public key.
/// </summary>
/// <param name="signedDoc"></param>
/// <param name="keyPub">Public key</param>
/// <returns></returns>
public static bool CheckSignature(System.Xml.XmlDocument signedDoc, string keyPub)
{
System.Security.Cryptography.RSACryptoServiceProvider rsa = new System.Security.Cryptography.RSACryptoServiceProvider();
rsa.FromXmlString(keyPub);
// Create a new SignedXml object and pass it
// the XML document class.
System.Security.Cryptography.Xml.SignedXml sx = new System.Security.Cryptography.Xml.SignedXml(signedDoc);
// Load the first <signature> node.
sx.LoadXml(GetSignatureFromSignedDoc(signedDoc));
// Check the signature and return the result.
return sx.CheckSignature(rsa);
}
