#region Disclaimer / License
// Copyright (C) 2015, The Duplicati Team
// http://www.duplicati.com, info@duplicati.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.FtpClient;
using System.Net.Security;
using System.Security.Authentication;
using Duplicati.Library.Interface;
using Uri = System.Uri;
using CoreUtility = Duplicati.Library.Utility.Utility;
namespace Duplicati.Library.Backend.AlternativeFTP
{
// ReSharper disable once RedundantExtendsListEntry
public class AlternativeFtpBackend : IBackend, IStreamingBackend
{
private System.Net.NetworkCredential _userInfo;
private const string OPTION_ACCEPT_SPECIFIED_CERTIFICATE = "accept-specified-ssl-hash"; // Global option
private const string OPTION_ACCEPT_ANY_CERTIFICATE = "accept-any-ssl-certificate"; // Global option
private const FtpDataConnectionType DEFAULT_DATA_CONNECTION_TYPE = FtpDataConnectionType.AutoPassive;
private const FtpEncryptionMode DEFAULT_ENCRYPTION_MODE = FtpEncryptionMode.None;
private const SslProtocols DEFAULT_SSL_PROTOCOLS = SslProtocols.Default;
private const string CONFIG_KEY_AFTP_ENCRYPTION_MODE = "aftp-encryption-mode";
private const string CONFIG_KEY_AFTP_DATA_CONNECTION_TYPE = "aftp-data-connection-type";
private const string CONFIG_KEY_AFTP_SSL_PROTOCOLS = "aftp-ssl-protocols";
private const string TEST_FILE_NAME = "duplicati-access-privileges-test.tmp";
private const string TEST_FILE_CONTENT = "This file used by Duplicati to test access permissions and could be safely deleted.";
// ReSharper disable InconsistentNaming
private static readonly string DEFAULT_DATA_CONNECTION_TYPE_STRING = DEFAULT_DATA_CONNECTION_TYPE.ToString();
private static readonly string DEFAULT_ENCRYPTION_MODE_STRING = DEFAULT_ENCRYPTION_MODE.ToString();
private static readonly string DEFAULT_SSL_PROTOCOLS_STRING = DEFAULT_SSL_PROTOCOLS.ToString();
// ReSharper restore InconsistentNaming
private readonly string _url;
private readonly bool _listVerify = true;
private readonly FtpEncryptionMode _encryptionMode;
private readonly FtpDataConnectionType _dataConnectionType;
private readonly SslProtocols _sslProtocols;
private readonly byte[] _copybuffer = new byte[CoreUtility.DEFAULT_BUFFER_SIZE];
private readonly bool _accepAllCertificates;
private readonly string[] _validHashes;
///
/// The localized name to display for this backend
///
public string DisplayName
{
get { return Strings.DisplayName; }
}
///
/// The protocol key, eg. ftp, http or ssh
///
public string ProtocolKey
{
get { return "aftp"; }
}
private FtpClient Client
{ get; set; }
public IList SupportedCommands
{
get
{
return new List(new ICommandLineArgument[] {
new CommandLineArgument("auth-password", CommandLineArgument.ArgumentType.Password, Strings.DescriptionAuthPasswordShort, Strings.DescriptionAuthPasswordLong),
new CommandLineArgument("auth-username", CommandLineArgument.ArgumentType.String, Strings.DescriptionAuthUsernameShort, Strings.DescriptionAuthUsernameLong),
new CommandLineArgument("disable-upload-verify", CommandLineArgument.ArgumentType.Boolean, Strings.DescriptionDisableUploadVerifyShort, Strings.DescriptionDisableUploadVerifyLong),
new CommandLineArgument(CONFIG_KEY_AFTP_DATA_CONNECTION_TYPE, CommandLineArgument.ArgumentType.Enumeration, Strings.DescriptionFtpDataConnectionTypeShort, Strings.DescriptionFtpDataConnectionTypeLong, DEFAULT_DATA_CONNECTION_TYPE_STRING, null, Enum.GetNames(typeof(FtpDataConnectionType))),
new CommandLineArgument(CONFIG_KEY_AFTP_ENCRYPTION_MODE, CommandLineArgument.ArgumentType.Enumeration, Strings.DescriptionFtpEncryptionModeShort, Strings.DescriptionFtpEncryptionModeLong, DEFAULT_ENCRYPTION_MODE_STRING, null, Enum.GetNames(typeof(FtpEncryptionMode))),
new CommandLineArgument(CONFIG_KEY_AFTP_SSL_PROTOCOLS, CommandLineArgument.ArgumentType.Flags, Strings.DescriptionSslProtocolsShort, Strings.DescriptionSslProtocolsLong, DEFAULT_SSL_PROTOCOLS_STRING, null, Enum.GetNames(typeof(SslProtocols))),
});
}
}
///
/// Initialize a new instance.
///
public AlternativeFtpBackend()
{
}
///
/// Initialize a new instance/
///
/// Configured url.
/// Configured options. cannot be null.
public AlternativeFtpBackend(string url, Dictionary options)
{
_accepAllCertificates = CoreUtility.ParseBoolOption(options, OPTION_ACCEPT_ANY_CERTIFICATE);
string certHash;
options.TryGetValue(OPTION_ACCEPT_SPECIFIED_CERTIFICATE, out certHash);
_validHashes = certHash == null ? null : certHash.Split(new[] { ",", ";" }, StringSplitOptions.RemoveEmptyEntries);
var u = new Utility.Uri(url);
u.RequireHost();
if (!string.IsNullOrEmpty(u.Username))
{
_userInfo = new System.Net.NetworkCredential();
_userInfo.UserName = u.Username;
if (!string.IsNullOrEmpty(u.Password))
_userInfo.Password = u.Password;
else if (options.ContainsKey("auth-password"))
_userInfo.Password = options["auth-password"];
}
else
{
if (options.ContainsKey("auth-username"))
{
_userInfo = new System.Net.NetworkCredential();
_userInfo.UserName = options["auth-username"];
if (options.ContainsKey("auth-password"))
_userInfo.Password = options["auth-password"];
}
}
//Bugfix, see http://connect.microsoft.com/VisualStudio/feedback/details/695227/networkcredential-default-constructor-leaves-domain-null-leading-to-null-object-reference-exceptions-in-framework-code
if (_userInfo != null)
_userInfo.Domain = "";
_url = u.SetScheme("ftp").SetQuery(null).SetCredentials(null, null).ToString();
if (!_url.EndsWith("/", StringComparison.Ordinal))
{
_url += "/";
}
_listVerify = !CoreUtility.ParseBoolOption(options, "disable-upload-verify");
// Process the aftp-data-connection-type option
string dataConnectionTypeString;
if (!options.TryGetValue(CONFIG_KEY_AFTP_DATA_CONNECTION_TYPE, out dataConnectionTypeString) || string.IsNullOrWhiteSpace(dataConnectionTypeString))
{
dataConnectionTypeString = null;
}
if (dataConnectionTypeString == null || !Enum.TryParse(dataConnectionTypeString, true, out _dataConnectionType))
{
_dataConnectionType = DEFAULT_DATA_CONNECTION_TYPE;
}
// Process the aftp-encryption-mode option
string encryptionModeString;
if (!options.TryGetValue(CONFIG_KEY_AFTP_ENCRYPTION_MODE, out encryptionModeString) || string.IsNullOrWhiteSpace(encryptionModeString))
{
encryptionModeString = null;
}
if (encryptionModeString == null || !Enum.TryParse(encryptionModeString, true, out _encryptionMode))
{
_encryptionMode = DEFAULT_ENCRYPTION_MODE;
}
// Process the aftp-ssl-protocols option
string sslProtocolsString;
if (!options.TryGetValue(CONFIG_KEY_AFTP_SSL_PROTOCOLS, out sslProtocolsString) || string.IsNullOrWhiteSpace(sslProtocolsString))
{
sslProtocolsString = null;
}
if (sslProtocolsString == null || !Enum.TryParse(sslProtocolsString, true, out _sslProtocols))
{
_sslProtocols = DEFAULT_SSL_PROTOCOLS;
}
}
public IEnumerable List()
{
return List("");
}
public IEnumerable List(string filename)
{
return List(filename, false);
}
private IEnumerable List(string filename, bool stripFile)
{
var list = new List();
string remotePath = filename;
try
{
var ftpClient = CreateClient();
// Get the remote path
var url = new Uri(this._url);
remotePath = "/" + (url.AbsolutePath.EndsWith("/", StringComparison.Ordinal) ? url.AbsolutePath.Substring(0, url.AbsolutePath.Length - 1) : url.AbsolutePath);
if (!string.IsNullOrEmpty(filename))
{
if (!stripFile)
{
// Append the filename
remotePath += filename;
}
else if (filename.Contains("/"))
{
remotePath += filename.Substring(0, filename.LastIndexOf("/", StringComparison.Ordinal));
}
// else: stripping the filename in this case ignoring it
}
foreach (FtpListItem item in ftpClient.GetListing(remotePath, FtpListOption.Modify | FtpListOption.Size | FtpListOption.DerefLinks))
{
switch (item.Type)
{
case FtpFileSystemObjectType.Directory:
{
if (item.Name == "." || item.Name == "..")
{
continue;
}
list.Add(new FileEntry(item.Name, -1, new DateTime(), item.Modified)
{
IsFolder = true,
});
break;
}
case FtpFileSystemObjectType.File:
{
list.Add(new FileEntry(item.Name, item.Size, new DateTime(), item.Modified));
break;
}
case FtpFileSystemObjectType.Link:
{
if (item.Name == "." || item.Name == "..")
{
continue;
}
if (item.LinkObject != null)
{
switch (item.LinkObject.Type)
{
case FtpFileSystemObjectType.Directory:
{
if (item.Name == "." || item.Name == "..")
{
continue;
}
list.Add(new FileEntry(item.Name, -1, new DateTime(), item.Modified)
{
IsFolder = true,
});
break;
}
case FtpFileSystemObjectType.File:
{
list.Add(new FileEntry(item.Name, item.Size, new DateTime(), item.Modified));
break;
}
}
}
break;
}
}
}
}// Message "Directory not found." string
catch (FtpCommandException ex)
{
if (ex.Message == "Directory not found.")
{
throw new FolderMissingException(Strings.MissingFolderError(remotePath, ex.Message), ex);
}
throw;
}
return list;
}
public void Put(string remotename, System.IO.Stream input)
{
string remotePath = remotename;
long streamLen = -1;
try
{
var ftpClient = CreateClient();
try
{
streamLen = input.Length;
}
// ReSharper disable once EmptyGeneralCatchClause
catch
{
}
// Get the remote path
remotePath = "";
if (!string.IsNullOrEmpty(remotename))
{
// Append the filename
remotePath += remotename;
}
using (var outputStream = ftpClient.OpenWrite(remotePath))
{
try
{
CoreUtility.CopyStream(input, outputStream, true, _copybuffer);
}
finally
{
outputStream.Close();
}
}
if (_listVerify)
{
var fileEntries = List(remotename, true);
foreach (var fileEntry in fileEntries)
{
if (fileEntry.Name.Equals(remotename) || fileEntry.Name.EndsWith("/" + remotename, StringComparison.Ordinal) || fileEntry.Name.EndsWith("\\" + remotename, StringComparison.Ordinal))
{
if (fileEntry.Size < 0 || streamLen < 0 || fileEntry.Size == streamLen)
{
return;
}
throw new UserInformationException(Strings.ListVerifySizeFailure(remotename, fileEntry.Size, streamLen), "AftpListVerifySizeFailure");
}
}
throw new UserInformationException(Strings.ListVerifyFailure(remotename, fileEntries.Select(n => n.Name)), "AftpListVerifySizeFailure");
}
}
catch (FtpCommandException ex)
{
if (ex.Message == "Directory not found.")
{
throw new FolderMissingException(Strings.MissingFolderError(remotePath, ex.Message), ex);
}
throw;
}
}
public void Put(string remotename, string localname)
{
using (System.IO.FileStream fs = System.IO.File.Open(localname, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))
{
Put(remotename, fs);
}
}
public void Get(string remotename, System.IO.Stream output)
{
var ftpClient = CreateClient();
// Get the remote path
var remotePath = "";
if (!string.IsNullOrEmpty(remotename))
{
// Append the filename
remotePath += remotename;
}
using (var inputStream = ftpClient.OpenRead(remotePath))
{
try
{
CoreUtility.CopyStream(inputStream, output, false, _copybuffer);
}
finally
{
inputStream.Close();
}
}
}
public void Get(string remotename, string localname)
{
using (System.IO.FileStream fs = System.IO.File.Open(localname, System.IO.FileMode.Create, System.IO.FileAccess.Write, System.IO.FileShare.None))
{
Get(remotename, fs);
}
}
public void Delete(string remotename)
{
var ftpClient = CreateClient();
// Get the remote path
var remotePath = "";
if (!string.IsNullOrEmpty(remotename))
{
// Append the filename
remotePath += remotename;
}
ftpClient.DeleteFile(remotePath);
}
///
/// A localized description of the backend, for display in the usage information
///
public string Description
{
get
{
return Strings.Description;
}
}
public string[] DNSName
{
get { return new string[] { new Uri(_url).Host }; }
}
private static System.IO.Stream StringToStream(string str)
{
var stream = new System.IO.MemoryStream();
var writer = new System.IO.StreamWriter(stream) { AutoFlush = true };
writer.Write(str);
return stream;
}
///
/// Test FTP access permissions.
///
public void Test()
{
var list = List();
// Delete test file if exists
if (list.Any(entry => entry.Name == TEST_FILE_NAME))
{
try
{
Delete(TEST_FILE_NAME);
}
catch (Exception e)
{
throw new Exception(string.Format(Strings.ErrorDeleteFile, e.Message), e);
}
}
// Test write permissions
using (var testStream = StringToStream(TEST_FILE_CONTENT))
{
try
{
Put(TEST_FILE_NAME, testStream);
}
catch (Exception e)
{
throw new Exception(string.Format(Strings.ErrorWriteFile, e.Message), e);
}
}
// Test read permissions
using (var stream = new System.IO.MemoryStream())
{
try
{
Get(TEST_FILE_NAME, stream);
}
catch (Exception e)
{
throw new Exception(string.Format(Strings.ErrorReadFile, e.Message), e);
}
}
// Cleanup
try
{
Delete(TEST_FILE_NAME);
}
catch (Exception e)
{
throw new Exception(string.Format(Strings.ErrorDeleteFile, e.Message), e);
}
}
public void CreateFolder()
{
var client = CreateClient();
var url = new Uri(_url);
// Get the remote path
var remotePath = url.AbsolutePath.EndsWith("/", StringComparison.Ordinal) ? url.AbsolutePath.Substring(0, url.AbsolutePath.Length - 1) : url.AbsolutePath;
// Try to create the directory
client.CreateDirectory(remotePath, true);
}
public void Dispose()
{
if (Client != null)
Client.Dispose();
Client = null;
_userInfo = null;
}
private FtpClient CreateClient()
{
if (this.Client == null) // Create connection if it doesn't exist yet
{
var url = _url;
var uri = new Uri(url);
var ftpClient = new FtpClient
{
Host = uri.Host,
Port = uri.Port == -1 ? 21 : uri.Port,
Credentials = _userInfo,
EncryptionMode = _encryptionMode,
DataConnectionType = _dataConnectionType,
SslProtocols = _sslProtocols,
EnableThreadSafeDataConnections = true, // Required to work properly but can result in up to 3 connections being used even when you expect just one..
};
ftpClient.ValidateCertificate += HandleValidateCertificate;
// Get the remote path
var remotePath = uri.AbsolutePath.EndsWith("/", StringComparison.Ordinal) ? uri.AbsolutePath.Substring(0, uri.AbsolutePath.Length - 1) : uri.AbsolutePath;
ftpClient.SetWorkingDirectory(remotePath);
this.Client = ftpClient;
} // else reuse existing connection
return this.Client;
}
private void HandleValidateCertificate(FtpClient control, FtpSslValidationEventArgs e)
{
if (e.PolicyErrors == SslPolicyErrors.None || _accepAllCertificates)
{
e.Accept = true;
return;
}
try
{
var certHash = (_validHashes != null && _validHashes.Length > 0) ? CoreUtility.ByteArrayAsHexString(e.Certificate.GetCertHash()) : null;
if (certHash != null)
{
if (_validHashes.Any(hash => !string.IsNullOrEmpty(hash) && certHash.Equals(hash, StringComparison.OrdinalIgnoreCase)))
{
e.Accept = true;
}
}
}
catch
{
e.Accept = false;
}
}
}
}