C#、VB.NET使用HttpWebRequest访问https地址(SSL)的实现

今天，有个网友问我：

用httpwebrequest访问一个SSL类型的地址 https://xxxx 时，报错 “未能为 SSL/TLS 安全通道建立信任关系(Could not establish trust relationship for the SSL/TLS secure channel)”

查了下MSDN，找到了解决方法，SSL网站，连接时需要提供证书，对于非必须提供客户端证书的情况，只要返回一个安全确认即可。但是此方法的实现，在.NET 1.1 和 .NET 2.0 下是不同的，下面写出2个framework版本下的实现方法：

使用的命名空间：

using System.Net;
using System.Net.Security;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;

.Net 2.0

public bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{   
    //直接确认，否则打不开   
    return true;
}
    
private void button1_Click(object sender, EventArgs e)
{
    ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
    HttpWebRequest req = (HttpWebRequest)WebRequest.CreateDefault(new Uri("https://zu14.cn/"));
    req.Method = "GET";
    HttpWebResponse res = (HttpWebResponse)req.GetResponse();
    //...正常使用了，和访问普通的 http:// 地址一样了
}

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.Net 1.1

internal class AcceptAllCertificatePolicy : ICertificatePolicy
{
    public AcceptAllCertificatePolicy()
    {
    }

    public bool CheckValidationResult(ServicePoint sPoint, System.Security.Cryptography.X509Certificates.X509Certificate cert, WebRequest wRequest, int certProb)
    {
        //直接确认
        return true;
    }
} 
    
private void button1_Click(object sender, EventArgs e)
{
    ServicePointManager.CertificatePolicy = new AcceptAllCertificatePolicy();
    HttpWebRequest req = (HttpWebRequest)WebRequest.CreateDefault(new Uri("https://zu14.cn/"));
    req.Method = "GET";
    HttpWebResponse res = (HttpWebResponse)req.GetResponse();
    //...正常使用了，和访问普通的 http:// 地址一样了
}