private static bool InternalValidate(XElement signatureToValidate, Federation.Federation federation, ICredentialVault vault, bool checkForTrustedCertificates, bool checkRevoked)
{
if (signatureToValidate.NodeType != XmlNodeType.Element)
{
throw new ModelException("The signature to validate must be a ds:Signature Element!");
}
var xml = new XmlDocument();
xml.Load(signatureToValidate.CreateReader());
bool isAssertion = false;
var nsManager = NameSpaces.MakeNsManager(xml.NameTable);
var sig = xml.SelectSingleNode("/soap:Envelope/soap:Header/wsse:Security/ds:Signature", nsManager) as XmlElement;
if (sig == null)
{
sig = xml.SelectSingleNode("/saml:Assertion/ds:Signature", nsManager) as XmlElement;
isAssertion = true;
if (sig == null)
{
sig = xml.GetElementsByTagName("Signature", NameSpaces.ds)[0] as XmlElement;
isAssertion = true;
}
}
if (sig == null)
{
return(false);
}
var signature = new Signature();
sig = MakeSignatureCheckSamlCompliant(sig);
signature.LoadXml(sig);
var cert = signature.KeyInfo.Cast <KeyInfoX509Data>().Select(d => d.Certificates[0] as X509Certificate2).FirstOrDefault(c => c != null);
if (!ConfigurationManager.AppSettings.AllKeys.Contains("CheckDate") || !ConfigurationManager.AppSettings["CheckDate"].ToLower().Equals("false"))
{
//check if certificate is expired or cannot be used yet
if (!CheckDates(cert))
{
return(false);
}
}
//Check that the certificate used for validation is trusted. If a Federation has been specified
//the signature must have been created by the STS. If no federation is specified, the
//certificate must be trusted in the CredentialVault.
if (checkForTrustedCertificates)
{
var trusted = false;
if (federation != null)
{
trusted = federation.IsValidSTSCertificate(cert);
}
else if (vault != null)
{
trusted = vault.IsTrustedCertificate(cert);
}
if (!trusted)
{
throw new ModelException("The certificate that signed the security token is not trusted!");
}
}
// check the certificates CRL if the certificate is revoked
if (checkRevoked)
{
CrlCertificateStatusChecker crlChecker = new CrlCertificateStatusChecker();
var isValid = crlChecker.GetRevocationStatus(cert).IsValid;
if (!isValid)
{
throw new ModelException("The certificate or one in its certificate chain has been revoked!");
}
}
// check if xml is actually signed with key sent in message
var signed = new SealSignedXml(signatureToValidate);
if (isAssertion)
{
return(signed.CheckAssertionSignature());
}
return(signed.CheckEnvelopeSignature());
}