Editare

Partajați prin

FtpWebRequest.EnableSsl Property

  • Reference

Definition

Namespace:
System.Net
Assembly:
System.Net.Requests.dll
Assembly:
System.dll
Assembly:
netstandard.dll
Source:
FtpWebRequest.cs
Source:
FtpWebRequest.cs
Source:
FtpWebRequest.cs

Gets or sets a Boolean that specifies that an SSL connection should be used.

public:
 property bool EnableSsl { bool get(); void set(bool value); };
public bool EnableSsl { get; set; }
member this.EnableSsl : bool with get, set
Public Property EnableSsl As Boolean

Property Value

Boolean

true if control and data transmissions are encrypted; otherwise, false. The default value is false.

Exceptions

InvalidOperationException

The connection to the FTP server has already been established.

Examples

The following code example uses an encrypted connection to download the directory listing from an FTP server.

static bool ListFilesOnServerSsl( Uri^ serverUri )
{
   // The serverUri should start with the ftp:// scheme.
   if ( serverUri->Scheme != Uri::UriSchemeFtp )
   {
      return false;
   }

   // Get the object used to communicate with the server.
   FtpWebRequest^ request = dynamic_cast<FtpWebRequest^>(WebRequest::Create( serverUri ));
   request->Method = WebRequestMethods::Ftp::ListDirectory;
   request->EnableSsl = true;

   // Get the ServicePoint object used for this request, and limit it to one connection.
   // In a real-world application you might use the default number of connections (2),
   // or select a value that works best for your application.
   ServicePoint^ sp = request->ServicePoint;
   Console::WriteLine( "ServicePoint connections = {0}.", sp->ConnectionLimit );
   sp->ConnectionLimit = 1;
   FtpWebResponse^ response = dynamic_cast<FtpWebResponse^>(request->GetResponse());
   Console::WriteLine( "The content length is {0}", response->ContentLength );

   // The following streams are used to read the data returned from the server.
   Stream^ responseStream = nullptr;
   StreamReader^ readStream = nullptr;
   responseStream = response->GetResponseStream();
   readStream = gcnew StreamReader( responseStream,System::Text::Encoding::UTF8 );

   // Display the data received from the server.
   Console::WriteLine( readStream->ReadToEnd() );
   Console::WriteLine( "List status: {0}", response->StatusDescription );
   readStream->Close();
   response->Close();

   Console::WriteLine( "Banner message: {0}", response->BannerMessage );

   Console::WriteLine( "Welcome message: {0}", response->WelcomeMessage );

   Console::WriteLine( "Exit message: {0}", response->ExitMessage );

   return true;
}

public static bool ListFilesOnServerSsl(Uri serverUri)
{
    // The serverUri should start with the ftp:// scheme.
    if (serverUri.Scheme != Uri.UriSchemeFtp)
    {
        return false;
    }
    // Get the object used to communicate with the server.
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverUri);
    request.Method = WebRequestMethods.Ftp.ListDirectory;
    request.EnableSsl = true;

    // Get the ServicePoint object used for this request, and limit it to one connection.
    // In a real-world application you might use the default number of connections (2),
    // or select a value that works best for your application.

    ServicePoint sp = request.ServicePoint;
    Console.WriteLine("ServicePoint connections = {0}.", sp.ConnectionLimit);
    sp.ConnectionLimit = 1;

    FtpWebResponse response = (FtpWebResponse) request.GetResponse();
     Console.WriteLine("The content length is {0}", response.ContentLength);
    // The following streams are used to read the data returned from the server.
    Stream responseStream = null;
    StreamReader readStream = null;
    try
    {
        responseStream = response.GetResponseStream();
        readStream = new StreamReader(responseStream, System.Text.Encoding.UTF8);

        if (readStream != null)
        {
            // Display the data received from the server.
            Console.WriteLine(readStream.ReadToEnd());
        }
        Console.WriteLine("List status: {0}",response.StatusDescription);
    }
    finally
    {
        if (readStream != null)
        {
            readStream.Close();
        }
        if (response != null)
        {
            response.Close();
        }
    }

    Console.WriteLine("Banner message: {0}",
        response.BannerMessage);

    Console.WriteLine("Welcome message: {0}",
        response.WelcomeMessage);

    Console.WriteLine("Exit message: {0}",
        response.ExitMessage);
    return true;
}

Remarks

Caution

Unless the EnableSsl property is true, all data and commands, including your user name and password information, are sent to the server in clear text. Anyone monitoring network traffic can view your credentials and use them to connect to the server. If you are connecting to an FTP server that requires credentials and supports SSL, you should set EnableSsl to true.

The "AUTH TLS" command is sent to the server to request an encrypted session. If the server does not recognize this command, you receive a WebException exception.

Applies to

See also