PASV mode options and Hybrid Authenticator

.gitignore

@@ -1,6 +1,8 @@
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 
+RunConfig.xml
+
 # User-specific files
 *.suo
 *.user

Library/Authenticate/FtpUser.cs

@@ -0,0 +1,26 @@
+// <copyright file="FtpUser.cs" company="Zhaoquan Huang">
+// Copyright (c) Zhaoquan Huang. All rights reserved
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Zhaobang.FtpServer.Authenticate
+{
+    /// <summary>
+    /// Ftp authenticator user model.
+    /// </summary>
+    public class FtpUser
+    {
+        /// <summary>
+        /// Gets or sets user name.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets user password.
+        /// </summary>
+        public string Password { get; set; }
+    }
+}

Library/Authenticate/HybridAuthenticator.cs

@@ -0,0 +1,43 @@
+// <copyright file="HybridAuthenticator.cs" company="Zhaoquan Huang">
+// Copyright (c) Zhaoquan Huang. All rights reserved
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Zhaobang.FtpServer.Authenticate
+{
+    /// <summary>
+    /// The authenticator that accepts both userName/password and anonymous.
+    /// </summary>
+    public class HybridAuthenticator : IAuthenticator
+    {
+        private readonly List<FtpUser> users;
+        private readonly bool enableAnonymous;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="HybridAuthenticator"/> class.
+        /// </summary>
+        /// <param name="users">The users to accept.</param>
+        /// <param name="enableAnonymous">Enable anonymous mode or not.</param>
+        public HybridAuthenticator(List<FtpUser> users, bool enableAnonymous)
+        {
+            this.users = users;
+            this.enableAnonymous = enableAnonymous;
+        }
+
+        /// <summary>
+        /// Verifies if the username-password pair is correct.
+        /// </summary>
+        /// <param name="userName">The user name user inputted.</param>
+        /// <param name="password">The password user inputted.</param>
+        /// <returns>Whether the pair is correct.</returns>
+        public bool Authenticate(string userName, string password)
+        {
+            if (this.enableAnonymous && userName.ToUpper() == "ANONYMOUS") return true;
+            return users.Any(u => u.Name.ToUpper() == userName.ToUpper() && u.Password.ToUpper() == password.ToUpper());
+        }
+    }
+}

Library/Connections/ControlConnection.cs

@@ -14,6 +14,7 @@
 using Zhaobang.FtpServer.Connections;
 using Zhaobang.FtpServer.Exceptions;
 using Zhaobang.FtpServer.File;
+using Zhaobang.FtpServer.Options;
 
 namespace Zhaobang.FtpServer.Connections
 {
@@ -30,6 +31,7 @@ internal class ControlConnection : IDisposable
 
         private readonly IPEndPoint remoteEndPoint;
         private readonly IPEndPoint localEndPoint;
+        private readonly FtpServerOptions ftpServerOptions;
 
         /// <summary>
         /// This should be available all time, but needs to check
@@ -78,7 +80,8 @@ internal class ControlConnection : IDisposable
         /// </summary>
         /// <param name="server">The <see cref="FtpServer"/> that creates the connection.</param>
         /// <param name="tcpClient">The TCP client of the connection.</param>
-        internal ControlConnection(FtpServer server, TcpClient tcpClient)
+        /// <param name="ftpServerOptions">The ftp options.</param>
+        internal ControlConnection(FtpServer server, TcpClient tcpClient, FtpServerOptions ftpServerOptions)
         {
             this.server = server;
             this.tcpClient = tcpClient;
@@ -90,8 +93,8 @@ internal ControlConnection(FtpServer server, TcpClient tcpClient)
 
             var localUri = new Uri("ftp://" + this.tcpClient.Client.LocalEndPoint.ToString());
             localEndPoint = new IPEndPoint(IPAddress.Parse(localUri.Host), localUri.Port);
-
-            dataConnection = server.DataConnector.GetDataConnection(localEndPoint.Address);
+            this.ftpServerOptions = ftpServerOptions;
+            dataConnection = server.DataConnector.GetDataConnection(localEndPoint.Address, ftpServerOptions.PassiveMinPort, ftpServerOptions.PassiveMaxPort);
 
             stream = this.tcpClient.GetStream();
         }
@@ -235,6 +238,7 @@ private async Task ProcessCommandAsync(string message)
                     await fileProvider.DeleteAsync(parameter);
                     await ReplyAsync(FtpReplyCode.FileActionOk, "Delete succeeded");
                     return;
+                case "XRMD":
                 case "RMD":
                     if (!authenticated)
                     {
@@ -244,6 +248,7 @@ private async Task ProcessCommandAsync(string message)
                     await fileProvider.DeleteDirectoryAsync(parameter);
                     await ReplyAsync(FtpReplyCode.FileActionOk, "Directory deleted");
                     return;
+                case "XMKD":
                 case "MKD":
                     if (!authenticated)
                     {
@@ -257,6 +262,7 @@ await ReplyAsync(
                             "\"{0}\"",
                             fileProvider.GetWorkingDirectory().Replace("\"", "\"\"")));
                     return;
+                case "XPWD":
                 case "PWD":
                     if (!authenticated)
                     {
@@ -654,7 +660,11 @@ await ReplyAsync(
         private async Task CommandPasvAsync()
         {
             var localEP = dataConnection.Listen();
-            var ipBytes = localEP.Address.GetAddressBytes();
+
+            // var ipBytes = localEP.Address.GetAddressBytes();
+            var passiveIpValid = IPAddress.TryParse(ftpServerOptions.PassiveIp, out var pasvIP);
+            if (!passiveIpValid) pasvIP = localEP.Address;
+            var ipBytes = pasvIP.GetAddressBytes();
             if (ipBytes.Length != 4) throw new Exception();
             var passiveEPString =
                 string.Format(

Library/Connections/IDataConnectionFactory.cs

@@ -18,7 +18,9 @@ public interface IDataConnectionFactory
         /// Gets <see cref="IDataConnection"/> for a control connection.
         /// </summary>
         /// <param name="localIP">The server IP that was connected by the user.</param>
+        /// <param name="minPort">The min port in PASSIVE mode.</param>
+        /// <param name="maxPort">The max port in PASSIVE mode.</param>
         /// <returns>The <see cref="IDataConnection"/> for that control connection.</returns>
-        IDataConnection GetDataConnection(IPAddress localIP);
+        IDataConnection GetDataConnection(IPAddress localIP, int minPort, int maxPort);
     }
 }

Library/Connections/LocalDataConnection.cs

@@ -18,9 +18,12 @@ namespace Zhaobang.FtpServer.Connections
     /// </summary>
     public class LocalDataConnection : IDisposable, IDataConnection
     {
-        private const int MinPort = 1024;
-        private const int MaxPort = 65535;
-        private static int lastUsedPort = new Random().Next(MinPort, MaxPort);
+#pragma warning disable SA1306 // Field names should begin with lower-case letter
+        private static int MinPort = 1024;
+        private static int MaxPort = 65535;
+#pragma warning restore SA1306 // Field names should begin with lower-case letter
+        private static object portLock = new object();
+        private static int lastUsedPort = 0; // new Random().Next(MinPort, MaxPort);
 
         private readonly IPAddress listeningIP;
 
@@ -39,8 +42,18 @@ public class LocalDataConnection : IDisposable, IDataConnection
         /// NO connection will be initiated immediately.
         /// </summary>
         /// <param name="localIP">The IP which was connected by the user.</param>
-        public LocalDataConnection(IPAddress localIP)
+        /// <param name="minPort">The min port in PASSIVE mode.</param>
+        /// <param name="maxPort">The max port in PASSIVE mode.</param>
+        public LocalDataConnection(IPAddress localIP, int minPort, int maxPort)
         {
+            MinPort = minPort;
+            MaxPort = maxPort;
+            if (lastUsedPort == 0)
+            {
+                lock (portLock)
+                    if (lastUsedPort == 0)
+                        lastUsedPort = new Random().Next(MinPort, MaxPort);
+            }
             listeningIP = localIP;
         }
 

Library/Connections/LocalDataConnectionFactory.cs

@@ -21,10 +21,12 @@ public class LocalDataConnectionFactory : IDataConnectionFactory
         /// Gets <see cref="LocalDataConnection"/> for a user.
         /// </summary>
         /// <param name="localIP">The IP which was connected by the user.</param>
+        /// <param name="minPort">The min port in PASSIVE mode.</param>
+        /// <param name="maxPort">The max port in PASSIVE mode.</param>
         /// <returns>The data connection for the user.</returns>
-        public IDataConnection GetDataConnection(IPAddress localIP)
+        public IDataConnection GetDataConnection(IPAddress localIP, int minPort, int maxPort)
         {
-            return new LocalDataConnection(localIP);
+            return new LocalDataConnection(localIP, minPort, maxPort);
         }
     }
 }

Library/Connections/SslLocalDataConnection.cs

@@ -20,8 +20,10 @@ namespace Zhaobang.FtpServer.Connections
     /// </summary>
     public class SslLocalDataConnection : IDisposable, IDataConnection, ISslDataConnection
     {
-        private const int MinPort = 1024;
-        private const int MaxPort = 65535;
+#pragma warning disable SA1306 // Field names should begin with lower-case letter
+        private static int MinPort = 1024;
+        private static int MaxPort = 65535;
+#pragma warning restore SA1306 // Field names should begin with lower-case letter
         private static int lastUsedPort = new Random().Next(MinPort, MaxPort);
 
         private readonly IPAddress listeningIP;
@@ -43,8 +45,12 @@ public class SslLocalDataConnection : IDisposable, IDataConnection, ISslDataConn
         /// </summary>
         /// <param name="localIP">The IP which was connected by the user.</param>
         /// <param name="certificate">The certificate to upgrade to encrypted stream.</param>
-        public SslLocalDataConnection(IPAddress localIP, X509Certificate certificate)
+        /// <param name="minPort">The min port for PASV mode.</param>
+        /// <param name="maxPort">The max port for PASV mode.</param>
+        public SslLocalDataConnection(IPAddress localIP, X509Certificate certificate, int minPort, int maxPort)
         {
+            MinPort = minPort;
+            MaxPort = maxPort;
             listeningIP = localIP;
             this.certificate = certificate ?? throw new ArgumentNullException(nameof(certificate));
         }

Library/Connections/SslLocalDataConnectionFactory.cs

@@ -31,10 +31,12 @@ public SslLocalDataConnectionFactory(X509Certificate certificate)
         /// Gets the data connection instance.
         /// </summary>
         /// <param name="localIP">The local IP to bind the socket.</param>
+        /// <param name="minPort">The min port for PASV mode.</param>
+        /// <param name="maxPort">The max port for PASV mode.</param>
         /// <returns>The created data connection instance.</returns>
-        public IDataConnection GetDataConnection(IPAddress localIP)
+        public IDataConnection GetDataConnection(IPAddress localIP, int minPort, int maxPort)
         {
-            return new SslLocalDataConnection(localIP, certificate);
+            return new SslLocalDataConnection(localIP, certificate, minPort, maxPort);
         }
     }
 }

Library/FtpServer.cs

@@ -14,6 +14,7 @@
 using Zhaobang.FtpServer.Authenticate;
 using Zhaobang.FtpServer.Connections;
 using Zhaobang.FtpServer.File;
+using Zhaobang.FtpServer.Options;
 using Zhaobang.FtpServer.Trace;
 
 namespace Zhaobang.FtpServer
@@ -29,6 +30,8 @@ public sealed class FtpServer
         private readonly IControlConnectionSslFactory controlConnectionSslFactory;
         private readonly FtpTracer tracer = new FtpTracer();
 
+        private readonly FtpServerOptions ftpServerOptions;
+
         private IPEndPoint endPoint;
         private TcpListener tcpListener;
 
@@ -57,7 +60,7 @@ public FtpServer(
             IFileProviderFactory fileProviderFactory,
             IDataConnectionFactory dataConnFactory,
             IAuthenticator authenticator)
-            : this(endPoint, fileProviderFactory, dataConnFactory, authenticator, null)
+            : this(endPoint, fileProviderFactory, dataConnFactory, authenticator, null, new FtpServerOptions())
         {
         }
 
@@ -70,12 +73,14 @@ public FtpServer(
         /// <param name="dataConnFactory">The <see cref="IDataConnectionFactory"/> to use.</param>
         /// <param name="authenticator">The <see cref="IAuthenticator"/> to use.</param>
         /// <param name="controlConnectionSslFactory">The <see cref="IControlConnectionSslFactory"/> to upgrade control connection to SSL.</param>
+        /// <param name="ftpServerOptions">The <see cref="FtpServerOptions"/> set ftp options.</param>
         public FtpServer(
             IPEndPoint endPoint,
             IFileProviderFactory fileProviderFactory,
             IDataConnectionFactory dataConnFactory,
             IAuthenticator authenticator,
-            IControlConnectionSslFactory controlConnectionSslFactory)
+            IControlConnectionSslFactory controlConnectionSslFactory,
+            FtpServerOptions ftpServerOptions)
         {
             this.endPoint = endPoint;
             tcpListener = new TcpListener(endPoint);
@@ -85,6 +90,8 @@ public FtpServer(
             this.authenticator = authenticator;
             this.controlConnectionSslFactory = controlConnectionSslFactory;
 
+            this.ftpServerOptions = ftpServerOptions;
+
             tracer.CommandInvoked += Tracer_CommandInvoked;
             tracer.ReplyInvoked += Tracer_ReplyInvoked;
         }
@@ -139,7 +146,7 @@ public async Task RunAsync(CancellationToken cancellationToken)
 
                     try
                     {
-                        ControlConnection handler = new ControlConnection(this, tcpClient);
+                        ControlConnection handler = new ControlConnection(this, tcpClient, ftpServerOptions);
                         var result = handler.RunAsync(cancellationToken);
                     }
                     catch (Exception)

Library/Options/FtpServerOptions.cs

@@ -0,0 +1,31 @@
+// <copyright file="FtpServerOptions.cs" company="Zhaoquan Huang">
+// Copyright (c) Zhaoquan Huang. All rights reserved
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Zhaobang.FtpServer.Options
+{
+    /// <summary>
+    /// Ftp server options.
+    /// </summary>
+    public class FtpServerOptions
+    {
+        /// <summary>
+        /// Gets or sets the min port of the FTP file system in passive mode.
+        /// </summary>
+        public string PassiveIp { get; set; } = string.Empty;
+
+        /// <summary>
+        /// Gets or sets the min port of the FTP file system in passive mode.
+        /// </summary>
+        public int PassiveMinPort { get; set; } = 1024;
+
+        /// <summary>
+        /// Gets or sets the max port of the FTP file system in passive mode.
+        /// </summary>
+        public int PassiveMaxPort { get; set; } = 65535;
+    }
+}

Library/README.md

@@ -49,7 +49,8 @@ var server = new FtpServer(
     new MyFileProviderFactory(),
     new MyDataConnectionFactory(),
     new MyAuthenticator(),
-    new MyControlConnectionSslFactory()
+    new MyControlConnectionSslFactory(),
+    new FtpServerOptions()
 );
 // the remaining is same as simple use
 ```
@@ -65,7 +66,7 @@ var fileProviderFactory = new SimpleFileProviderFactory(config.BaseDirectory);
 var dataConnectionFactory = new SslLocalDataConnectionFactory(certificate);
 var authenticator = new AnonymousAuthenticator();
 var controlConnectionSslFactory = new ControlConnectionSslFactory(certificate);
-var server = new FtpServer(ep, fileProviderFactory, dataConnectionFactory, authenticator, controlConnectionSslFactory);
+var server = new FtpServer(ep, fileProviderFactory, dataConnectionFactory, authenticator, controlConnectionSslFactory, new FtpServerOptions());
 ```
 
 The .NET Standard 1.4 version requires your own implementation of those classes. You can refer to the source code for a sample implementation.