C#从基于FTPS的FTP server下载数据 (FtpWebRequest 的使用)SSL 加密

 1 using System;
 2 using System.Net;
 3 using System.IO;
 4 using System.Net.Security;
 5 using System.Security.Cryptography.X509Certificates;
 6 
 7 namespace FtpWebrequestBlogCase
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             DownLoadFile("ftp://xxx/xxx.zip");
14             Console.ReadKey();
15         }
16 
17         public static void DownLoadFile(string addr)
18         {
19             var req = (FtpWebRequest)WebRequest.Create(addr);
20             req.Method = WebRequestMethods.Ftp.DownloadFile;
21             req.UseBinary = true;
22             req.UsePassive = true;
23             const string userName = "xxxx";
24             const string password = "xxxx";
25             req.Credentials = new NetworkCredential(userName, password);
26 
27             //如果要连接的 FTP 服务器要求凭据并支持安全套接字层 (SSL)，则应将 EnableSsl 设置为 true。
28             //如果不写会报出421错误（服务不可用）
29             req.EnableSsl = true;
30 
31             // 首次连接FTP server时，会有一个证书分配过程。
32             //如果没有下面的代码会报异常：
33             //System.Security.Authentication.AuthenticationException: 根据验证过程，远程证书无效。
34             ServicePointManager.ServerCertificateValidationCallback =
35                 new RemoteCertificateValidationCallback(ValidateServerCertificate);
36             try
37             {
38                 using (var res = (FtpWebResponse)req.GetResponse())
39                 {
40                     const string localfile = "test.zip";
41                     var fs = new FileStream(localfile, FileMode.Create, FileAccess.Write);
42                     const int buffer = 1024*1000;
43                     var b = new byte[buffer];
44                     var i = 0;
45                     var stream = res.GetResponseStream();
46                     while (stream != null && (i = stream.Read(b, 0, buffer)) > 0)
47                     {
48                         fs.Write(b, 0, i);
49                         fs.Flush();
50                     }
51                 }
52                 Console.WriteLine("done!");
53 
54             }
55             catch (Exception ex)
56             {
57                 var message = ex.ToString();
58                 Console.WriteLine(message);
59             }
60             finally
61             {
62 
63             }
64         }
65 
66         public static bool ValidateServerCertificate
67             (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
68         {
69             return true;
70         }
71     }
72 }