使用 Windows 服务上承载的 WCF 针对 ADFS 进行身份验证

我有一个wcf服务，用于查询ADFS以获取SAML令牌。这是来自 Web 的常见代码段，用于查询 ADFS 并取回 SAML 令牌。然而，它总是最终在线路返回通道处断开。问题（rst）; .错误为 ID3082：请求范围无效或不受支持。至少在高级别上，我无法确定错误是在 ADFS 服务器端还是 WCF 服务的配置方式或代码。请帮忙。

public SecurityToken GetSamlToken()
{
    using (var factory = new WSTrustChannelFactory(
        new UserNameWSTrustBinding(SecurityMode.TransportWithMessageCredential),
        new EndpointAddress(new Uri("https://serv/adfs/services/trust/13/usernamemixed"))))
    {
        factory.Credentials.UserName.UserName = "username";
        factory.Credentials.UserName.Password = "password";
        factory.Credentials.ServiceCertificate.Authentication.CertificateValidationMode = X509CertificateValidationMode.None;
        factory.TrustVersion = TrustVersion.WSTrust13;                
        WSTrustChannel channel = null;                
        try
        {
            string KeyType;
            var rst = new RequestSecurityToken
            {
                RequestType = WSTrust13Constants.RequestTypes.Issue,
                AppliesTo = new EndpointAddress("net.tcp://localhost:xxxx/Service1/mex"),                         
                KeyType = Microsoft.IdentityModel.Protocols.WSTrust.WSTrust13Constants.KeyTypes.Bearer,                                        
            };
            channel = (WSTrustChannel)factory.CreateChannel();
            return channel.Issue(rst);
        }
        finally
        {
            if (channel != null)
            {
                channel.Abort();
            }
            factory.Abort();
        }
    }
}