C# WebRequest處理Https請求

正常情況下，處理https和http沒有什么區別，如以下代碼，顯示了https://www.softlayer.com/的內容

string url = “https://www.softlayer.com/”;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string encoding = response.ContentEncoding;
if (encoding == null || encoding.Length < 1) {
    encoding = "UTF-8"; //默認編碼
}
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
Console.Write(reader.ReadToEnd());
response.Close();

和http的不同就是地址由http改為了https

但是，如果你將 https://www.softlayer.com/ 改為 https://softlayer.com/，會發現一個異常
未能為 SSL/TLS 安全通道建立信任關系
怎么回事？ 用瀏覽器試一下，訪問 https://www.softlayer.com/ 沒有問題
訪問 https://softlayer.com/ 會有證書問題（雖然是我們自己造成的）
這就對了，如果有證書問題，不做特殊處理，將會拋出異常
怎么處理呢？ 如果是dot net 2.0 或以上，加上一個確認函數就可以了，代碼如：

ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
string url = “https://softlayer.com/”;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string encoding = response.ContentEncoding;
if (encoding == null || encoding.Length < 1) {
    encoding = "UTF-8"; //默認編碼
}
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
Console.Write(reader.ReadToEnd());
response.Close();

public bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) { // Always accept
    Console.WriteLine(“accept ” + certificate.GetName());
    return true; //總是接受
}

using System.Net;
using System.IO;
using System.Web;
using System.Net.Security;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

如果是dot net 1.1，寫法略有不同

ServicePointManager.CertificatePolicy = new AcceptAllCertificatePolicy();

internal class AcceptAllCertificatePolicy : ICertificatePolicy {
    public AcceptAllCertificatePolicy() {
    }
    public bool CheckValidationResult(ServicePoint sPoint, System.Security.Cryptography.X509Certificates.X509Certificate cert, WebRequest wRequest, int certProb) {
    // Always accept
    return true;
    }
}

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