internal static ExtractionResult ExtractHttpPost(IFormCollection requestForm, X509Certificate2 idpCertificate)
{
var payload = GetSamlPayload(requestForm);
var message = Convert.FromBase64String(payload.Item2).ToXmlDocument();
var result = new ExtractionResult
{
Message = message,
RelayState = requestForm[SamlAuthenticationDefaults.RelayStateKey]
};
var signatureNode = message.RemoveSignature();
if (signatureNode == null || idpCertificate == null)
{
return(result);
}
var signedXml = new SignedXml(message);
signedXml.LoadXml((XmlElement)signatureNode);
result.HasValidSignature = signedXml.CheckSignature(idpCertificate, true);
return(result);
}
internal static ExtractionResult ExtractHttpRedirect(IQueryCollection requestQuery, X509Certificate2 idpCertificate)
{
var payload = GetSamlPayload(requestQuery);
var result = new ExtractionResult();
var binaryMessage = Convert.FromBase64String(payload.Item2);
result.Message = binaryMessage.ToXmlDocument();
if (requestQuery.TryGetValue(SamlAuthenticationDefaults.RelayStateKey, out var relayState))
{
result.RelayState = relayState;
}
if (!requestQuery.TryGetValue(SamlAuthenticationDefaults.SignatureKey, out var signatureString) ||
!requestQuery.TryGetValue(SamlAuthenticationDefaults.SignatureAlgorithmKey, out var sigAlg) ||
idpCertificate == null)
{
return(result);
}
var signature = Convert.FromBase64String(signatureString);
var signatureDescription = (SignatureDescription)CryptoConfig.CreateFromName(sigAlg);
if (signatureDescription == null)
{
throw new SamlException($"Signature Algorithm '{sigAlg}' is not supported.");
}
var signedSequence = new StringBuilder();
signedSequence.Append($"{payload.Item1}={payload.Item2}&");
if (result.RelayState != null)
{
signedSequence.Append($"RelayState={result.RelayState}&");
}
signedSequence.Append($"SigAlg={sigAlg}");
var hashAlgorithm = signatureDescription.CreateDigest();
hashAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(signedSequence.ToString()));
result.HasValidSignature = signatureDescription.CreateDeformatter(idpCertificate.PublicKey.Key).VerifySignature(hashAlgorithm, signature);
return(result);
}
