private string ValidateIssuer(X509Certificate2 issuerCertificate)
{
Contract.Requires(issuerCertificate != null);
Contract.Ensures(!String.IsNullOrEmpty(Contract.Result<string>()));
if ((Configuration == null) || (Configuration.IssuerNameRegistry == null))
{
throw new SecurityTokenException("No IssuerNameRegistry configured");
}
string issuer = Configuration.IssuerNameRegistry.GetIssuerName(new X509SecurityToken(issuerCertificate));
if (string.IsNullOrEmpty(issuer))
{
throw new SecurityTokenException("No issuer name found");
}
return issuer;
}