HTTP Basic Authentication验证WCF Data Service

WCF Data Service是OData协议，也是RESTFul Service的一种，上篇文章已经介绍了HTTP Basic Authentication for RESTFul Service，也介绍了服务端如何设置。现在我们来一下客户端怎么样调用。

按照OData and Authentication – Part 6 – Custom Basic Authentication的介绍的方法调用：

Entities  ctx = new Entities(new Uri("http://localhost:8080/YupskyDataService.svc"));
var serviceCreds = new NetworkCredential("admin", "admin");
var cache = new CredentialCache();
var serviceUri = new Uri("http://localhost:8080/YupskyDataService.svc");
cache.Add(serviceUri, "Basic", serviceCreds);
ctx.Credentials = cache;
ctx.SendingRequest += new EventHandler<SendingRequestEventArgs>(OnSendingRequest);

static void OnSendingRequest(object sender, SendingRequestEventArgs e)
{
    var creds = "user" + ":" + "password";
    var bcreds = Encoding.ASCII.GetBytes(creds);
    var base64Creds = Convert.ToBase64String(bcreds);
    e.RequestHeaders.Add("Authorization", "Basic " + base64Creds);
}

上面的代码可以完成http方式的调用，如果是https方式调用就会出现错误：

“The remote certificate is invalid according to the validation procedure”

[WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.]

此时需要进行强制验证通过，解决方法是在执行你的代码之前先回调一个名为ServicePointManager的类，每当http客户端的堆栈进行证书验证时，都会检查是否可以回调，如果可以，则执行你你的代码。而要挂接该回调，则必须提供类型RemoteCertificateValidationCallback的一个委托，在调用之前加入如下代码：

ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(OnValidationCallback);

public bool OnValidationCallback(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors errors)
{
  5:      //不管服务端证书怎么样，都通过校验，嘿嘿           return true;
}

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HttpWebRequest使用SSL连接的时候，处理服务器证书不安全的方法