IPWorks SSH 2022 .NET Edition
Version 22.0 [Build 8304]

SFTPServer Component

Properties   Methods   Events   Config Settings   Errors  

The SFTPServer component is used to create a SFTP Server.

Syntax

nsoftware.IPWorksSSH.Sftpserver

Remarks

The SFTPServer component provides a simple way to create a SFTP server. Any SFTP client will be able to connect and transfer files to and from the server.

Getting Started

To begin, first provide a valid certificate with private key in the SSHCert property.

Optionally set the RootDirectory property to a valid local path. If this property is set the component will serve files from this location and when clients connect they will see this as their initial directory. If this property is not set then the component will fire events allowing customized responses for each operation.

To start the server set Listening to true.

Client Authentication

Client authentication is handled through the SSHUserAuthRequest event. Inside this event, the Accept parameter determines whether authentication is accepted; this parameter should be set to True if a successful authentication is detected and False otherwise.

When a client connects, the AuthMethod parameter indicates the method of authentication the client wishes to use. Connecting clients will initially attempt authentication with an AuthMethod of "none". This is done with the expectation that the request will fail and the server will provide a list of support authentication methods. The client then selects an available method and re-authenticates. If AuthMethod is "none", Accept should be set to False.

For password authentication, the User parameter will hold the client's username and the AuthParam parameter will hold the password provided by the client. An external list of known usernames and passwords should be maintained to check these values against.

For publickey authentication, the User parameter will hold the client's username and the AuthParam parameter will hold the key provided by the client. This key should be compared to and external list of known keys and usernames.

For keyboard-interactive authentication, the SSHUserAuthRequest event will fire multiple times; once for each prompt and response sent by the client. The index of the response is specified as a suffix in the AuthMethod parameter (e.g. keyboard-interactive-1, keyboard-interactive-2, etc), and AuthParam will contain the client's response to the prompt. Finally, SSHUserAuthRequest will fire one last time with AuthMethod set to "keyboard-interactive" and AuthParam set to an empty string. The Accept parameter must be set to True each time the event fires in order for the authentication process to succeed.

Directory Listing

When a client requests a directory listing, the DirList event fires with the Path parameter set to the directory to enumerate. If the directory listing is allowed, the appropriate set of files should be passed to the SetFileList method. The StatusCode parameter should be set according to the status of the operation, and the valid status codes can be found in the documentation for the DirList event.

Handling Events

Event handlers are the primary method of customizing the component's functionality. When a client attempts to connect, open a file, authenticate to the server, etc, the corresponding SFTPServer event will fire to allow for custom handling of the client's request.

The following events are fired both before and after the requested operation is executed:

Each of these events has a BeforeExec event parameter that is True when the event is fired before execution of the operation, and False after execution of the operation. Handling the event before execution provides an opportunity to use custom logic to determine whether the operation should be denied, diverted, or otherwise modified. Handling the event after execution provides an opportunity to report success or any errors related to the operation to the client.

The following events are fired only after the requested operation is executed:

Any logic to deny opening a file for read or write should be done in the FileOpen event handler.

Threading in Server Applications

In .NET, all socket-based components perform all Socket.IO through asynchronous methods. Each call consumes a thread from the system's thread pool, and thus the number of concurrent calls is limited to the number of worker threads returned by System.Threading.ThreadPool.GetMaxThreads. When using several components that can each create a socket connection or a single component that can create multiple socket connections, the application may enter a state in which all of the pool threads are in use for receiving. In a scenario such as this, the remote hosts may be waiting for data from the application before sending, but the application cannot send that data because all the threads are tied up waiting for inbound data. This is particularly important for server applications that use a daemon component.

For example, say a server application 'S' has a max thread pool size of three, and clients 'A' and 'B' connect to it and each client uploads a large file. After all uploads are complete, 'S' enqueues an asynchronous read request in the thread pool for each client. Because no work is being done, the thread pool immediately consumes two threads that wait for any further data from 'A' and 'B'. While 'S' is still processing the first two files it has received, client 'C' connects and uploads a relatively small file. Similarly, once that upload has completed 'S' enqueues a third read request, and the thread pool immediately consumes the third and final thread to wait for further data from 'C'. Once 'S' completes processing any of the files, it will enqueue a send request. However, because all three threads are in use and waiting for data from the clients, the send operation cannot be completed. The entire system becomes deadlocked because each of the clients is waiting for data from the server, which cannot send that data because all of its pool threads are in turn waiting for data from the clients.

To avoid a deadlock situation such as this, it is necessary to ensure that the maximum number of socket connections an application can make is always at least one less than the number of available worker threads. One method to achieve this is to call System.Threading.ThreadPool.SetMaxThreads during the application's startup to set the maximum number of threads to a value high enough to support the application for the duration of its execution. Another option is to trap an event such as ConnectionRequest and Disconnected from each component instance with logic to manage the maximum thread pool size according to the application's current needs.

Note: Server components are designed to process events as they occur. To ensure that events are processed in a timely manner, DoEvents should be called in a loop after the server is started.

Property List


The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

ConnectionBacklogThis property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.
ConnectionsA collection of currently connected SFTP clients.
DefaultAuthMethodsSpecifies the supported authentication methods.
DefaultTimeoutAn initial timeout value to be used by incoming connections.
KeyboardInteractiveMessageThe instructions to send to the client during keyboard-interactive authentication.
KeyboardInteractivePromptsA collection of prompts to present to the user for keyboard-interactive authentication.
ListeningIf set to True, the component accepts incoming connections on LocalPort.
LocalHostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPortThe TCP port in the local host where the component listens.
RootDirectoryThe root directory for the entire SFTP server.
SSHCertA certificate to be used during SSH negotiation.
SSHCompressionAlgorithmsA comma-separated list containing all allowable compression algorithms.
SSHEncryptionAlgorithmsA comma-separated list containing all allowable encryption algorithms.

Method List


The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

ConfigSets or retrieves a configuration setting.
DisconnectThis method disconnects the specified client.
DoEventsProcesses events from the internal message queue.
ExchangeKeysCauses the component to exchange a new set of session keys on the specified connection.
ResetReset the component.
SetFileListSets the file list for a connection during a directory listing request.
ShutdownThis method shuts down the server.
StartListeningThis method starts listening for incoming connections.
StopListeningThis method stops listening for new connections.

Event List


The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

ConnectedThis event is fired immediately after a connection completes (or fails).
ConnectionRequestThis event is fired when a request for connection comes from a remote host.
DirCreateFires when a client wants to create a new directory.
DirListFires when a client attempts to open a directory for listing.
DirRemoveFires when a client wants to delete a directory.
DisconnectedThis event is fired when a connection is closed.
ErrorInformation about errors during data delivery.
FileCloseFires when a client attempts to close an open file or directory handle.
FileOpenFires when a client wants to open or create a file.
FileReadFires when a client wants to read from an open file.
FileRemoveFires when a client wants to delete a file.
FileRenameFires when a client wants to rename a file.
FileWriteFires when a client wants to write to an open file.
GetAttributesFires when a client needs to get file information.
LogFires once for each log message.
ResolvePathFires when a client attempts to canonicalize a path.
SetAttributesFires when a client attempts to set file or directory attributes.
SSHStatusShows the progress of the secure connection.
SSHUserAuthRequestFires when a client attempts to authenticate a connection.

Config Settings


The following is a list of config settings for the component with short descriptions. Click on the links for further details.

DirListBufferSize[ConnectionId]The number of entries to be returned in one response to a request for a directory listing.
MaskSensitiveMasks passwords in logs.
ProtocolVersionThe highest allowable SFTP version to use.
ResolveOwnerAndGroup[ConnectionId]Whether to automatically determine the FileOwner and FileGroup.
RestrictUserToHomeDir[ConnectionId]Whether to restrict the user to their home directory.
ServerEOLSpecifies the line endings used in files on the server.
SFTPErrorMessage[ConnectionId]Specifies the error message to be returned to the client.
UserRootDirectory[ConnectionId]The path of the server root directory for a particular user.
AltSSHCertCountThe number of records in the AltSSHCert configuration settings.
AltSSHCertStore[i]The name of the certificate store.
AltSSHCertStorePassword[i]The password used to open the certificate store.
AltSSHCertStoreType[i]The type of certificate store.
AltSSHCertSubject[i]The alternative certificate subject.
KeyboardInteractivePrompts[ConnectionId]Specifies custom keyboard-interactive prompts for particular connections.
KeyRenegotiationThresholdSets the threshold for the SSH Key Renegotiation.
LogLevelSpecifies the level of detail that is logged.
MaxAuthAttemptsThe maximum authentication attempts allowed before forcing a disconnect.
ServerSSHVersionStringThe SSH version string sent to connecting clients.
SSHKeepAliveCountMaxThe maximum number of keep alive packets to send without a response.
SSHKeepAliveIntervalThe interval between keep alive packets.
SSHKeyExchangeAlgorithmsSpecifies the supported key exchange algorithms.
SSHMacAlgorithmsSpecifies the supported Mac algorithms.
SSHPubKeyAuthSigAlgorithmsSpecifies the allowed signature algorithms used by a client performing public key authentication.
SSHPublicKeyAlgorithmsSpecifies the supported public key algorithms for the server's public key.
SSHVersionPatternThe pattern used to match the remote host's version string.
UserAuthBanner[ConnectionId]A custom user authentication banner.
AllowedClientsA comma-separated list of host names or IP addresses that can access the component.
BindExclusivelyWhether or not the component considers a local port reserved for exclusive use.
CloseStreamAfterTransferIf true, the component will close the upload or download stream after the transfer.
DefaultConnectionTimeoutThe inactivity timeout applied to the SSL handshake.
InBufferSizeThe size in bytes of the incoming queue of the socket.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
MaxConnectionsThe maximum number of connections available.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
PreferredDHGroupBitsSize of the Diffie-Hellman group, in bits.
TcpNoDelayWhether or not to delay when sending packets.
UseBackgroundThreadWhether threads created by the component are background threads.
UseIPv6Whether to use IPv6.
BuildInfoInformation about the product's build.
GUIAvailableTells the component whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the component whether or not to use the system security libraries or an internal implementation.

ConnectionBacklog Property (SFTPServer Component)

This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.

Syntax

public int ConnectionBacklog { get; set; }
Public Property ConnectionBacklog As Integer

Default Value

5

Remarks

This property contains the maximum number of pending connections maintained by the TCP/IP subsystem. This value reflects the SOMAXCONN option for the main listening socket. The default value for most systems is 5. You may set this property to a larger value if the server is expected to receive a large number of connections, and queuing them is desirable.

This property is not available at design time.

Connections Property (SFTPServer Component)

A collection of currently connected SFTP clients.

Syntax

public SFTPConnectionMap Connections { get; }
Public ReadOnly Property Connections As SFTPConnectionMap

Remarks

This property is a collection of currently connected clients. All of the connections may be managed using this property. Each connection is described by the different fields of the SFTPConnection type.

This property is read-only.

DefaultAuthMethods Property (SFTPServer Component)

Specifies the supported authentication methods.

Syntax

public string DefaultAuthMethods { get; set; }
Public Property DefaultAuthMethods As String

Default Value

"password,publickey"

Remarks

This property specifies the supported authentication methods. The client will choose one of the supported mechanisms when authenticating to the component.

This must be a comma separated list of values. For more information on authenticating clients see the SSHUserAuthRequest event.

The following is a list of methods implemented by the component:

noneThis authentication method is used by most SSH clients to obtain the list of authentication methods available for the user's account. In most cases you should not accept a request using this authentication method.
passwordAuthParam will contain the user-supplied password. If the password is correct, set Accept to true.
publickeyAuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept to true. The component will then handle verifying the digital signature and will respond to the client accordingly.
keyboard-interactiveSSHUserAuthRequest will fire multiple times for keyboard-interactive authentication: It will fire once for each response sent by the client in the SSH_MSG_USERAUTH_INFO_RESPONSE packet (one for each prompt specified by the daemon). The index of each response will be specified as a suffix in AuthMethod, with AuthParam containing the response to the corresponding prompt (e.g keyboard-interactive-1, keyboard-interactive-2 and so on). Finally, SSHUserAuthRequest will fire one last time with AuthMethod set to "keyboard-interactive" and AuthParam set to an empty string. The daemon must set Accept to true every time to allow the authentication process to succeed.

DefaultTimeout Property (SFTPServer Component)

An initial timeout value to be used by incoming connections.

Syntax

public int DefaultTimeout { get; set; }
Public Property DefaultTimeout As Integer

Default Value

60

Remarks

If the DefaultTimeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If DefaultTimeout is set to a positive value, the component will wait for the operation to complete before returning control.

The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the component throws an exception.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the DefaultTimeout property is 60 (seconds).

KeyboardInteractiveMessage Property (SFTPServer Component)

The instructions to send to the client during keyboard-interactive authentication.

Syntax

public string KeyboardInteractiveMessage { get; set; }
Public Property KeyboardInteractiveMessage As String

Default Value

""

Remarks

This property should be set to the main instructions to send to the client during keyboard-interactive authentication.

KeyboardInteractivePrompts Property (SFTPServer Component)

A collection of prompts to present to the user for keyboard-interactive authentication.

Syntax

public SSHPromptList KeyboardInteractivePrompts { get; }
Public Property KeyboardInteractivePrompts As SSHPromptList

Remarks

This property is a collection of prompts to present to the user during keyboard-authentication. It is used together with the KeyboardInteractiveMessage property.

Listening Property (SFTPServer Component)

If set to True, the component accepts incoming connections on LocalPort.

Syntax

public bool Listening { get; set; }
Public Property Listening As Boolean

Default Value

False

Remarks

This property indicates whether the component is listening for connections on the port specified by the LocalPort property.

Note: Use the StartListening and StopListening methods to control whether the component is listening.

This property is not available at design time.

LocalHost Property (SFTPServer Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

public string LocalHost { get; set; }
Public Property LocalHost As String

Default Value

""

Remarks

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (SFTPServer Component)

The TCP port in the local host where the component listens.

Syntax

public int LocalPort { get; set; }
Public Property LocalPort As Integer

Default Value

22

Remarks

The LocalPort property must be set before TCPServer starts listening. If its value is 0, then the TCP/IP subsystem picks a port number at random. The port number can be found by checking the value of the LocalPort property after TCPServer is in listening mode (after successfully assigning True to the Listening property).

The service port is not shared among servers (i.e. there can be only one TCPServer 'listening' on a particular port at one time).

RootDirectory Property (SFTPServer Component)

The root directory for the entire SFTP server.

Syntax

public string RootDirectory { get; set; }
Public Property RootDirectory As String

Default Value

""

Remarks

RootDirectory specifies the root of the SFTP server ('/'). If a value is provided, the component will handle all requests by doing all file operations itself, but the events will still give you the opportunity to override the default values/operations as necessary.

If a value is not provided, all events must be handled appropriately to ensure correct operation.

SSHCert Property (SFTPServer Component)

A certificate to be used during SSH negotiation.

Syntax

public Certificate SSHCert { get; set; }
Public Property SSHCert As Certificate

Remarks

The digital certificate that the server will use during SSH negotiation. A certificate with a private key is required for session authentication and encryption.

This is the server's certificate, and must be set prior to setting Listening to True.

SSHCompressionAlgorithms Property (SFTPServer Component)

A comma-separated list containing all allowable compression algorithms.

Syntax

public string SSHCompressionAlgorithms { get; set; }
Public Property SSHCompressionAlgorithms As String

Default Value

"none,zlib"

Remarks

During the SSH handshake, this list will be used to negotiate the compression algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, the component will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following compression algorithms are supported by the component:

  • zlib
  • zlib@openssh.com
  • none

SSHEncryptionAlgorithms Property (SFTPServer Component)

A comma-separated list containing all allowable encryption algorithms.

Syntax

public string SSHEncryptionAlgorithms { get; set; }
Public Property SSHEncryptionAlgorithms As String

Default Value

"aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,arcfour256,arcfour128,arcfour,cast128-cbc,aes256-gcm@openssh.com,aes128-gcm@openssh.com,chacha20-poly1305@openssh.com"

Remarks

During the SSH handshake, this list will be used to negotiate the encryption algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, the component will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following encryption algorithms are supported by the component:

aes256-ctr256-bit AES encryption in CTR mode
aes256-cbc256-bit AES encryption in CBC mode
aes192-ctr192-bit AES encryption in CTR mode
aes192-cbc192-bit AES encryption in CBC mode
aes128-ctr128-bit AES encryption in CTR mode
aes128-cbc128-bit AES encryption in CBC mode
3des-ctr192-bit (3-key) triple DES encryption in CTR mode
3des-cbc192-bit (3-key) triple DES encryption in CBC mode
cast128-cbcCAST-128 encryption
blowfish-cbcBlowfish encryption
arcfourARC4 encryption
arcfour128128-bit ARC4 encryption
arcfour256256-bit ARC4 encryption
aes256-gcm@openssh.com256-bit AES encryption in GCM mode.
aes128-gcm@openssh.com128-bit AES encryption in GCM mode.
chacha20-poly1305@openssh.comChaCha20 with Poly1305-AES encryption.

Config Method (SFTPServer Component)

Sets or retrieves a configuration setting.

Syntax

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);
Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Disconnect Method (SFTPServer Component)

This method disconnects the specified client.

Syntax

public void Disconnect(string connectionId);

Async Version
public async Task Disconnect(string connectionId);
public async Task Disconnect(string connectionId, CancellationToken cancellationToken);
Public Sub Disconnect(ByVal ConnectionId As String)

Async Version
Public Sub Disconnect(ByVal ConnectionId As String) As Task
Public Sub Disconnect(ByVal ConnectionId As String, cancellationToken As CancellationToken) As Task

Remarks

Calling this method will disconnect the client specified by the ConnectionId parameter.

DoEvents Method (SFTPServer Component)

Processes events from the internal message queue.

Syntax

public void DoEvents();

Async Version
public async Task DoEvents();
public async Task DoEvents(CancellationToken cancellationToken);
Public Sub DoEvents()

Async Version
Public Sub DoEvents() As Task
Public Sub DoEvents(cancellationToken As CancellationToken) As Task

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

ExchangeKeys Method (SFTPServer Component)

Causes the component to exchange a new set of session keys on the specified connection.

Syntax

public void ExchangeKeys(string connectionId);

Async Version
public async Task ExchangeKeys(string connectionId);
public async Task ExchangeKeys(string connectionId, CancellationToken cancellationToken);
Public Sub ExchangeKeys(ByVal ConnectionId As String)

Async Version
Public Sub ExchangeKeys(ByVal ConnectionId As String) As Task
Public Sub ExchangeKeys(ByVal ConnectionId As String, cancellationToken As CancellationToken) As Task

Remarks

SSH key renegotiation can be initiated by either end of an established SSH connection. ExchangeKeys allows the server to start such a renegotiation with the client. During this process, SSHStatus events will fire containing updates regarding the key negotiation process.

The SSH 2.0 specification recommends that key renegotiation be done once for 2 gigabytes (GB) of data processed by the connection, or once every day. This makes it more difficult to break the security of data-intensive or long-lived connections.

Reset Method (SFTPServer Component)

Reset the component.

Syntax

public void Reset();

Async Version
public async Task Reset();
public async Task Reset(CancellationToken cancellationToken);
Public Sub Reset()

Async Version
Public Sub Reset() As Task
Public Sub Reset(cancellationToken As CancellationToken) As Task

Remarks

This method will reset the component's properties to their default values.

SetFileList Method (SFTPServer Component)

Sets the file list for a connection during a directory listing request.

Syntax

public void SetFileList(string connectionId, string[] list);

Async Version
public async Task SetFileList(string connectionId, string[] list);
public async Task SetFileList(string connectionId, string[] list, CancellationToken cancellationToken);
Public Sub SetFileList(ByVal ConnectionId As String, ByVal List As String())

Async Version
Public Sub SetFileList(ByVal ConnectionId As String, ByVal List As String()) As Task
Public Sub SetFileList(ByVal ConnectionId As String, ByVal List As String(), cancellationToken As CancellationToken) As Task

Remarks

SetFileList should be set when a directory listing is requested by the client.

Shutdown Method (SFTPServer Component)

This method shuts down the server.

Syntax

public void Shutdown();

Async Version
public async Task Shutdown();
public async Task Shutdown(CancellationToken cancellationToken);
Public Sub Shutdown()

Async Version
Public Sub Shutdown() As Task
Public Sub Shutdown(cancellationToken As CancellationToken) As Task

Remarks

This method shuts down the server. Calling this method is equivalent to calling StopListening and then breaking every client connection by calling Disconnect.

StartListening Method (SFTPServer Component)

This method starts listening for incoming connections.

Syntax

public void StartListening();

Async Version
public async Task StartListening();
public async Task StartListening(CancellationToken cancellationToken);
Public Sub StartListening()

Async Version
Public Sub StartListening() As Task
Public Sub StartListening(cancellationToken As CancellationToken) As Task

Remarks

This method begins listening for incoming connections on the port specified by LocalPort. Once listening, events will fire as new clients connect and data are transferred.

To stop listening for new connections, call StopListening. To stop listening for new connections and to disconnect all existing clients, call Shutdown.

StopListening Method (SFTPServer Component)

This method stops listening for new connections.

Syntax

public void StopListening();

Async Version
public async Task StopListening();
public async Task StopListening(CancellationToken cancellationToken);
Public Sub StopListening()

Async Version
Public Sub StopListening() As Task
Public Sub StopListening(cancellationToken As CancellationToken) As Task

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

To stop listening and to disconnect all existing clients, call Shutdown instead.

Connected Event (SFTPServer Component)

This event is fired immediately after a connection completes (or fails).

Syntax

public event OnConnectedHandler OnConnected;

public delegate void OnConnectedHandler(object sender, SftpserverConnectedEventArgs e);

public class SftpserverConnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int StatusCode { get; }
  public string Description { get; }
  public int CertStoreType { get; set; }
  public string CertStore { get; set; }
  public string CertPassword { get; set; }
  public string CertSubject { get; set; }
}
Public Event OnConnected As OnConnectedHandler

Public Delegate Sub OnConnectedHandler(sender As Object, e As SftpserverConnectedEventArgs)

Public Class SftpserverConnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
  Public Property CertStoreType As Integer
  Public Property CertStore As String
  Public Property CertPassword As String
  Public Property CertSubject As String
End Class

Remarks

If the connection is made normally, StatusCode is 0, and Description is "OK".

If the connection fails, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error.

Please refer to the Error Codes section for more information.

ConnectionId is the connection Id of the client requesting the connection.

CertStoreType is the store type of the alternate certificate to use for this connection. The component supports both public and private keys in a variety of formats. When the cstAuto value is used the component will automatically determine the type. This field can take one of the following values:

0 (cstUser - default)For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note: this store type is not available in Java.
1 (cstMachine)For Windows, this specifies that the certificate store is a machine store. Note: this store type is not available in Java.
2 (cstPFXFile)The certificate store is the name of a PFX (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) format.
4 (cstJKSFile)The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: this store type is only available in Java.
5 (cstJKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in Java Key Store (JKS) format. Note: this store type is only available in Java.
6 (cstPEMKeyFile)The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 (cstPEMKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a private key and an optional certificate.
8 (cstPublicKeyFile)The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate.
9 (cstPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a PEM- or DER-encoded public key certificate.
10 (cstSSHPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains an SSH-style public key.
11 (cstP7BFile)The certificate store is the name of a PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 format.
13 (cstSSHPublicKeyFile)The certificate store is the name of a file that contains an SSH-style public key.
14 (cstPPKFile)The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 (cstPPKBlob)The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 (cstXMLFile)The certificate store is the name of a file that contains a certificate in XML format.
17 (cstXMLBlob)The certificate store is a string that contains a certificate in XML format.
18 (cstJWKFile)The certificate store is the name of a file that contains a JWK (JSON Web Key).
19 (cstJWKBlob)The certificate store is a string that contains a JWK (JSON Web Key).
20 (cstSecurityKey)The certificate is present on a physical security key accessible via a PKCS11 interface.

To use a security key the necessary data must first be collected using the CertMgr component. The ListStoreCertificates method may be called after setting CertStoreType to cstSecurityKey, CertStorePassword to the PIN, and CertStore to the full path of the PKCS11 dll. The certificate information returned in the CertList event's CertEncoded parameter may be saved for later use.

When using a certificate, pass the previously saved security key information as the Store and set StorePassword to the PIN.

Code Example: SSH Authentication with Security Key certmgr.CertStoreType = CertStoreTypes.cstSecurityKey; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstSecurityKey, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

21 (cstBCFKSFile)The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). Note: this store type is only available in Java and .NET.
22 (cstBCFKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. Note: this store type is only available in Java and .NET.
99 (cstAuto)The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically.

CertStore is the store name or location of the alternate certificate to use for this connection.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

CertPassword is the password of the certificate store containing the alternate certificate to use for this connection.

CertSubject is the subject of the alternate certificate to use for this connection.

The special value * matches any subject and will select the first certificate in the store. The certificate subject is a comma separated list of distinguished name fields and values. For instance "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are displayed below.

FieldMeaning
CNCommon Name. This is commonly a host name like www.server.com.
OOrganization
OUOrganizational Unit
LLocality
SState
CCountry
EEmail Address

If a field value contains a comma it must be quoted.

ConnectionRequest Event (SFTPServer Component)

This event is fired when a request for connection comes from a remote host.

Syntax

public event OnConnectionRequestHandler OnConnectionRequest;

public delegate void OnConnectionRequestHandler(object sender, SftpserverConnectionRequestEventArgs e);

public class SftpserverConnectionRequestEventArgs : EventArgs {
  public string Address { get; }
  public int Port { get; }
  public bool Accept { get; set; }
}
Public Event OnConnectionRequest As OnConnectionRequestHandler

Public Delegate Sub OnConnectionRequestHandler(sender As Object, e As SftpserverConnectionRequestEventArgs)

Public Class SftpserverConnectionRequestEventArgs Inherits EventArgs
  Public ReadOnly Property Address As String
  Public ReadOnly Property Port As Integer
  Public Property Accept As Boolean
End Class

Remarks

This event indicates an incoming connection. The connection is accepted by default. Address and Port will contain information about the remote host requesting the inbound connection. If you want to refuse it, you can set the Accept parameter to False.

DirCreate Event (SFTPServer Component)

Fires when a client wants to create a new directory.

Syntax

public event OnDirCreateHandler OnDirCreate;

public delegate void OnDirCreateHandler(object sender, SftpserverDirCreateEventArgs e);

public class SftpserverDirCreateEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public int FileType { get; }
  public long FileSize { get; }
  public string FileOwner { get; }
  public string FileGroup { get; }
  public int FilePermissions { get; }
  public long FileATime { get; }
  public long FileCreateTime { get; }
  public long FileMTime { get; }
  public int FileAttribBits { get; }
  public int FileAttribBitsValid { get; }
  public string OtherAttributes { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnDirCreate As OnDirCreateHandler

Public Delegate Sub OnDirCreateHandler(sender As Object, e As SftpserverDirCreateEventArgs)

Public Class SftpserverDirCreateEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property FileType As Integer
  Public ReadOnly Property FileSize As Long
  Public ReadOnly Property FileOwner As String
  Public ReadOnly Property FileGroup As String
  Public ReadOnly Property FilePermissions As Integer
  Public ReadOnly Property FileATime As Long
  Public ReadOnly Property FileCreateTime As Long
  Public ReadOnly Property FileMTime As Long
  Public ReadOnly Property FileAttribBits As Integer
  Public ReadOnly Property FileAttribBitsValid As Integer
  Public ReadOnly Property OtherAttributes As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Path parameter specifies the path and name of the new directory.

This event is fired both before and after the directory is created. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

File/Directory Attributes are specified using the following values:

FileType: The type of file. Can be one of the following values:

  • SSH_FILEXFER_TYPE_REGULAR (1)
  • SSH_FILEXFER_TYPE_DIRECTORY (2)
  • SSH_FILEXFER_TYPE_SYMLINK (3)
  • SSH_FILEXFER_TYPE_SPECIAL (4)
  • SSH_FILEXFER_TYPE_UNKNOWN (5)
  • SSH_FILEXFER_TYPE_SOCKET (6)
  • SSH_FILEXFER_TYPE_CHAR_DEVICE (7)
  • SSH_FILEXFER_TYPE_BLOCK_DEVICE (8)
  • SSH_FILEXFER_TYPE_FIFO (9)

FileSize: The file size, in bytes.

FileOwner: The file owner. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like user identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FileGroup: The file owner group. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like group identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FilePermissions: The POSIX-style file permissions.

FileATime: The file last-access time, in milliseconds since Jan 1, 1970 in UTC.

FileCreateTime: The file creation time, in milliseconds since Jan 1, 1970 in UTC.

FileMTime: The file last-modified time, in milliseconds since Jan 1, 1970 in UTC.

FileAttrBits: The file attributes, as a combination of the following values:

  • SSH_FILEXFER_ATTR_FLAGS_READONLY (0x00000001)
  • SSH_FILEXFER_ATTR_FLAGS_SYSTEM (0x00000002)
  • SSH_FILEXFER_ATTR_FLAGS_HIDDEN (0x00000004)
  • SSH_FILEXFER_ATTR_FLAGS_CASE_INSENSITIVE (0x00000008)
  • SSH_FILEXFER_ATTR_FLAGS_ARCHIVE (0x00000010)
  • SSH_FILEXFER_ATTR_FLAGS_ENCRYPTED (0x00000020)
  • SSH_FILEXFER_ATTR_FLAGS_COMPRESSED (0x00000040)
  • SSH_FILEXFER_ATTR_FLAGS_SPARSE (0x00000080)
  • SSH_FILEXFER_ATTR_FLAGS_APPEND_ONLY (0x00000100)
  • SSH_FILEXFER_ATTR_FLAGS_IMMUTABLE (0x00000200)
  • SSH_FILEXFER_ATTR_FLAGS_SYNC (0x00000400)
  • SSH_FILEXFER_ATTR_FLAGS_TRANSLATION_ERR (0x00000800)

FileAttrBitsValid: A mask specifying which bits in FileAttrBits are supported by the server.

OtherAttributes: A semi-colon (';') delimited list of Name=Value pairs of other attributes supported by SFTP. These include:

  • MIMEType (String)
  • AllocationSize (64-bit int)
  • ATimeNS (int): ATime nanoseconds
  • CreateTimeNS (int): CreateTime nanoseconds
  • MTimeNS (int): MTime nanoseconds
  • TextHint (8-bit int)
  • LinkCount (int)
  • UntranslatedName (String)

FileMimeType: The MIME type of the file.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

DirList Event (SFTPServer Component)

Fires when a client attempts to open a directory for listing.

Syntax

public event OnDirListHandler OnDirList;

public delegate void OnDirListHandler(object sender, SftpserverDirListEventArgs e);

public class SftpserverDirListEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnDirList As OnDirListHandler

Public Delegate Sub OnDirListHandler(sender As Object, e As SftpserverDirListEventArgs)

Public Class SftpserverDirListEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The DirList event fires when an SFTP client sends an SSH_FXP_OPENDIR request. The Path parameter will contain the path of the directory to list.

When necessary, you should call SetFileList with the list of files and directories in Path.

This event is fired both before and after the directory is listed. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

DirRemove Event (SFTPServer Component)

Fires when a client wants to delete a directory.

Syntax

public event OnDirRemoveHandler OnDirRemove;

public delegate void OnDirRemoveHandler(object sender, SftpserverDirRemoveEventArgs e);

public class SftpserverDirRemoveEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnDirRemove As OnDirRemoveHandler

Public Delegate Sub OnDirRemoveHandler(sender As Object, e As SftpserverDirRemoveEventArgs)

Public Class SftpserverDirRemoveEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Path parameter will specify the directory to delete.

This event is fired both before and after the directory is deleted. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

Disconnected Event (SFTPServer Component)

This event is fired when a connection is closed.

Syntax

public event OnDisconnectedHandler OnDisconnected;

public delegate void OnDisconnectedHandler(object sender, SftpserverDisconnectedEventArgs e);

public class SftpserverDisconnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int StatusCode { get; }
  public string Description { get; }
}
Public Event OnDisconnected As OnDisconnectedHandler

Public Delegate Sub OnDisconnectedHandler(sender As Object, e As SftpserverDisconnectedEventArgs)

Public Class SftpserverDisconnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

If the connection is broken normally, StatusCode is 0, and Description is "OK".

If the connection is broken for any other reason, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error.

Please refer to the Error Codes section for more information.

Error Event (SFTPServer Component)

Information about errors during data delivery.

Syntax

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, SftpserverErrorEventArgs e);

public class SftpserverErrorEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int ErrorCode { get; }
  public string Description { get; }
}
Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As SftpserverErrorEventArgs)

Public Class SftpserverErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

ConnectionId contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

FileClose Event (SFTPServer Component)

Fires when a client attempts to close an open file or directory handle.

Syntax

public event OnFileCloseHandler OnFileClose;

public delegate void OnFileCloseHandler(object sender, SftpserverFileCloseEventArgs e);

public class SftpserverFileCloseEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public string Handle { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileClose As OnFileCloseHandler

Public Delegate Sub OnFileCloseHandler(sender As Object, e As SftpserverFileCloseEventArgs)

Public Class SftpserverFileCloseEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property Handle As String
  Public Property StatusCode As Integer
End Class

Remarks

The FileClose event fires when an SFTP client sends an SSH_FXP_CLOSE request. The Path parameter will contain the path of the file to close.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

FileOpen Event (SFTPServer Component)

Fires when a client wants to open or create a file.

Syntax

public event OnFileOpenHandler OnFileOpen;

public delegate void OnFileOpenHandler(object sender, SftpserverFileOpenEventArgs e);

public class SftpserverFileOpenEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public int DesiredAccess { get; }
  public int Flags { get; }
  public int FileType { get; }
  public long FileSize { get; }
  public string FileOwner { get; }
  public string FileGroup { get; }
  public int FilePermissions { get; }
  public long FileATime { get; }
  public long FileCreateTime { get; }
  public long FileMTime { get; }
  public int FileAttribBits { get; }
  public int FileAttribBitsValid { get; }
  public string OtherAttributes { get; }
  public string Handle { get; set; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileOpen As OnFileOpenHandler

Public Delegate Sub OnFileOpenHandler(sender As Object, e As SftpserverFileOpenEventArgs)

Public Class SftpserverFileOpenEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property DesiredAccess As Integer
  Public ReadOnly Property Flags As Integer
  Public ReadOnly Property FileType As Integer
  Public ReadOnly Property FileSize As Long
  Public ReadOnly Property FileOwner As String
  Public ReadOnly Property FileGroup As String
  Public ReadOnly Property FilePermissions As Integer
  Public ReadOnly Property FileATime As Long
  Public ReadOnly Property FileCreateTime As Long
  Public ReadOnly Property FileMTime As Long
  Public ReadOnly Property FileAttribBits As Integer
  Public ReadOnly Property FileAttribBitsValid As Integer
  Public ReadOnly Property OtherAttributes As String
  Public Property Handle As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Path parameter specifies the path and name of the file to open, create. If the operation can be completed successfully, the Handle parameter should be set to the handle identifying the opened file. Please note that the Handle parameter is limited to a 256 byte string. By default, the component will provide an incremental numeric string value for the Handle.

This event is fired both before and after the file is opened. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

The Flags parameter specifies file creation and locking options as a bitmask. This may be a combination of the following values:

  • SSH_FXF_READ (0x00000001)
  • SSH_FXF_WRITE (0x00000002)
  • SSH_FXF_APPEND (0x00000004)
  • SSH_FXF_CREAT (0x00000008)
  • SSH_FXF_TRUNC (0x00000010)
  • SSH_FXF_EXCL (0x00000020)

The DesiredAccess parameter is a bitmask containing a combination of values from the ace-mask flags (Only for protocol versions 4 and up). This may be a combination of the following values:

  • ACE4_READ_DATA (0x00000001)
  • ACE4_LIST_DIRECTORY (0x00000001)
  • ACE4_WRITE_DATA (0x00000002)
  • ACE4_ADD_FILE (0x00000002)
  • ACE4_APPEND_DATA (0x00000004)
  • ACE4_ADD_SUBDIRECTORY (0x00000004)
  • ACE4_READ_NAMED_ATTRS (0x00000008)
  • ACE4_WRITE_NAMED_ATTRS (0x00000010)
  • ACE4_EXECUTE (0x00000020)
  • ACE4_DELETE_CHILD (0x00000040)
  • ACE4_READ_ATTRIBUTES (0x00000080)
  • ACE4_WRITE_ATTRIBUTES (0x00000100)
  • ACE4_DELETE (0x00010000)
  • ACE4_READ_ACL (0x00020000)
  • ACE4_WRITE_ACL (0x00040000)
  • ACE4_WRITE_OWNER (0x00080000)
  • ACE4_SYNCHRONIZE (0x00100000)
Please see RFC 3010 for more information on the semantics of these values.

File/Directory Attributes are specified using the following values:

FileType: The type of file. Can be one of the following values:

  • SSH_FILEXFER_TYPE_REGULAR (1)
  • SSH_FILEXFER_TYPE_DIRECTORY (2)
  • SSH_FILEXFER_TYPE_SYMLINK (3)
  • SSH_FILEXFER_TYPE_SPECIAL (4)
  • SSH_FILEXFER_TYPE_UNKNOWN (5)
  • SSH_FILEXFER_TYPE_SOCKET (6)
  • SSH_FILEXFER_TYPE_CHAR_DEVICE (7)
  • SSH_FILEXFER_TYPE_BLOCK_DEVICE (8)
  • SSH_FILEXFER_TYPE_FIFO (9)

FileSize: The file size, in bytes.

FileOwner: The file owner. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like user identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FileGroup: The file owner group. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like group identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FilePermissions: The POSIX-style file permissions.

FileATime: The file last-access time, in milliseconds since Jan 1, 1970 in UTC.

FileCreateTime: The file creation time, in milliseconds since Jan 1, 1970 in UTC.

FileMTime: The file last-modified time, in milliseconds since Jan 1, 1970 in UTC.

FileAttrBits: The file attributes, as a combination of the following values:

  • SSH_FILEXFER_ATTR_FLAGS_READONLY (0x00000001)
  • SSH_FILEXFER_ATTR_FLAGS_SYSTEM (0x00000002)
  • SSH_FILEXFER_ATTR_FLAGS_HIDDEN (0x00000004)
  • SSH_FILEXFER_ATTR_FLAGS_CASE_INSENSITIVE (0x00000008)
  • SSH_FILEXFER_ATTR_FLAGS_ARCHIVE (0x00000010)
  • SSH_FILEXFER_ATTR_FLAGS_ENCRYPTED (0x00000020)
  • SSH_FILEXFER_ATTR_FLAGS_COMPRESSED (0x00000040)
  • SSH_FILEXFER_ATTR_FLAGS_SPARSE (0x00000080)
  • SSH_FILEXFER_ATTR_FLAGS_APPEND_ONLY (0x00000100)
  • SSH_FILEXFER_ATTR_FLAGS_IMMUTABLE (0x00000200)
  • SSH_FILEXFER_ATTR_FLAGS_SYNC (0x00000400)
  • SSH_FILEXFER_ATTR_FLAGS_TRANSLATION_ERR (0x00000800)

FileAttrBitsValid: A mask specifying which bits in FileAttrBits are supported by the server.

OtherAttributes: A semi-colon (';') delimited list of Name=Value pairs of other attributes supported by SFTP. These include:

  • MIMEType (String)
  • AllocationSize (64-bit int)
  • ATimeNS (int): ATime nanoseconds
  • CreateTimeNS (int): CreateTime nanoseconds
  • MTimeNS (int): MTime nanoseconds
  • TextHint (8-bit int)
  • LinkCount (int)
  • UntranslatedName (String)

FileMimeType: The MIME type of the file.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

FileRead Event (SFTPServer Component)

Fires when a client wants to read from an open file.

Syntax

public event OnFileReadHandler OnFileRead;

public delegate void OnFileReadHandler(object sender, SftpserverFileReadEventArgs e);

public class SftpserverFileReadEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Handle { get; }
  public long FileOffset { get; }
  public int Length { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileRead As OnFileReadHandler

Public Delegate Sub OnFileReadHandler(sender As Object, e As SftpserverFileReadEventArgs)

Public Class SftpserverFileReadEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Handle As String
  Public ReadOnly Property FileOffset As Long
  Public ReadOnly Property Length As Integer
  Public Property StatusCode As Integer
End Class

Remarks

The Handle parameter identifies an open file on the server. FileOffset specifies the position from which to read data. Length specifies how much data to read. The data read should be set to through FileData

When processing a read request, the server should attempt to read at most Length bytes, but it is OK to read less than Length bytes as well, if no more data is available.

When there is no more data to be read from the file, set StatusCode to SSH_FXS_EOF.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

FileRemove Event (SFTPServer Component)

Fires when a client wants to delete a file.

Syntax

public event OnFileRemoveHandler OnFileRemove;

public delegate void OnFileRemoveHandler(object sender, SftpserverFileRemoveEventArgs e);

public class SftpserverFileRemoveEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileRemove As OnFileRemoveHandler

Public Delegate Sub OnFileRemoveHandler(sender As Object, e As SftpserverFileRemoveEventArgs)

Public Class SftpserverFileRemoveEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Path parameter will specify the file to delete.

This event is fired both before and after the file is removed. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

FileRename Event (SFTPServer Component)

Fires when a client wants to rename a file.

Syntax

public event OnFileRenameHandler OnFileRename;

public delegate void OnFileRenameHandler(object sender, SftpserverFileRenameEventArgs e);

public class SftpserverFileRenameEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public string NewPath { get; }
  public int Flags { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileRename As OnFileRenameHandler

Public Delegate Sub OnFileRenameHandler(sender As Object, e As SftpserverFileRenameEventArgs)

Public Class SftpserverFileRenameEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property NewPath As String
  Public ReadOnly Property Flags As Integer
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Path parameter will specify the file to rename and NewPath will specify the new name. The Flags parameter will be a bit mask of the values SSH_FXF_RENAME_OVERWRITE (0x00000001), SSH_FXF_RENAME_ATOMIC (0x00000002) and SSH_FXF_RENAME_NATIVE (0x00000004)

This event is fired both before and after the file is renamed. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

FileWrite Event (SFTPServer Component)

Fires when a client wants to write to an open file.

Syntax

public event OnFileWriteHandler OnFileWrite;

public delegate void OnFileWriteHandler(object sender, SftpserverFileWriteEventArgs e);

public class SftpserverFileWriteEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Handle { get; }
  public long FileOffset { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnFileWrite As OnFileWriteHandler

Public Delegate Sub OnFileWriteHandler(sender As Object, e As SftpserverFileWriteEventArgs)

Public Class SftpserverFileWriteEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Handle As String
  Public ReadOnly Property FileOffset As Long
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The Handle parameter identifies an open file on the server. FileOffset specifies the position at which to write data. The data to write can be retrieved through FileData

This event is fired both before and after the file is written. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

GetAttributes Event (SFTPServer Component)

Fires when a client needs to get file information.

Syntax

public event OnGetAttributesHandler OnGetAttributes;

public delegate void OnGetAttributesHandler(object sender, SftpserverGetAttributesEventArgs e);

public class SftpserverGetAttributesEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public int Flags { get; }
  public int FileType { get; set; }
  public long FileSize { get; set; }
  public string FileOwner { get; set; }
  public string FileGroup { get; set; }
  public int FilePermissions { get; set; }
  public long FileATime { get; set; }
  public long FileCreateTime { get; set; }
  public long FileMTime { get; set; }
  public int FileAttribBits { get; set; }
  public int FileAttribBitsValid { get; set; }
  public string OtherAttributes { get; set; }
  public int StatusCode { get; set; }
}
Public Event OnGetAttributes As OnGetAttributesHandler

Public Delegate Sub OnGetAttributesHandler(sender As Object, e As SftpserverGetAttributesEventArgs)

Public Class SftpserverGetAttributesEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property Flags As Integer
  Public Property FileType As Integer
  Public Property FileSize As Long
  Public Property FileOwner As String
  Public Property FileGroup As String
  Public Property FilePermissions As Integer
  Public Property FileATime As Long
  Public Property FileCreateTime As Long
  Public Property FileMTime As Long
  Public Property FileAttribBits As Integer
  Public Property FileAttribBitsValid As Integer
  Public Property OtherAttributes As String
  Public Property StatusCode As Integer
End Class

Remarks

The GetAttributes event fires when an SFTP client sends an SSH_FXP_STAT, SSH_FXP_LSTAT or SSH_FXP_FSTAT request. Path is the file path. Flags specifies the set of file attributes the client is interested in.

File/Directory Attributes are specified using the following values:

FileType: The type of file. Can be one of the following values:

  • SSH_FILEXFER_TYPE_REGULAR (1)
  • SSH_FILEXFER_TYPE_DIRECTORY (2)
  • SSH_FILEXFER_TYPE_SYMLINK (3)
  • SSH_FILEXFER_TYPE_SPECIAL (4)
  • SSH_FILEXFER_TYPE_UNKNOWN (5)
  • SSH_FILEXFER_TYPE_SOCKET (6)
  • SSH_FILEXFER_TYPE_CHAR_DEVICE (7)
  • SSH_FILEXFER_TYPE_BLOCK_DEVICE (8)
  • SSH_FILEXFER_TYPE_FIFO (9)

FileSize: The file size, in bytes.

FileOwner: The file owner. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like user identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FileGroup: The file owner group. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like group identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FilePermissions: The POSIX-style file permissions.

FileATime: The file last-access time, in milliseconds since Jan 1, 1970 in UTC.

FileCreateTime: The file creation time, in milliseconds since Jan 1, 1970 in UTC.

FileMTime: The file last-modified time, in milliseconds since Jan 1, 1970 in UTC.

FileAttrBits: The file attributes, as a combination of the following values:

  • SSH_FILEXFER_ATTR_FLAGS_READONLY (0x00000001)
  • SSH_FILEXFER_ATTR_FLAGS_SYSTEM (0x00000002)
  • SSH_FILEXFER_ATTR_FLAGS_HIDDEN (0x00000004)
  • SSH_FILEXFER_ATTR_FLAGS_CASE_INSENSITIVE (0x00000008)
  • SSH_FILEXFER_ATTR_FLAGS_ARCHIVE (0x00000010)
  • SSH_FILEXFER_ATTR_FLAGS_ENCRYPTED (0x00000020)
  • SSH_FILEXFER_ATTR_FLAGS_COMPRESSED (0x00000040)
  • SSH_FILEXFER_ATTR_FLAGS_SPARSE (0x00000080)
  • SSH_FILEXFER_ATTR_FLAGS_APPEND_ONLY (0x00000100)
  • SSH_FILEXFER_ATTR_FLAGS_IMMUTABLE (0x00000200)
  • SSH_FILEXFER_ATTR_FLAGS_SYNC (0x00000400)
  • SSH_FILEXFER_ATTR_FLAGS_TRANSLATION_ERR (0x00000800)

FileAttrBitsValid: A mask specifying which bits in FileAttrBits are supported by the server.

OtherAttributes: A semi-colon (';') delimited list of Name=Value pairs of other attributes supported by SFTP. These include:

  • MIMEType (String)
  • AllocationSize (64-bit int)
  • ATimeNS (int): ATime nanoseconds
  • CreateTimeNS (int): CreateTime nanoseconds
  • MTimeNS (int): MTime nanoseconds
  • TextHint (8-bit int)
  • LinkCount (int)
  • UntranslatedName (String)

FileMimeType: The MIME type of the file.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

Log Event (SFTPServer Component)

Fires once for each log message.

Syntax

public event OnLogHandler OnLog;

public delegate void OnLogHandler(object sender, SftpserverLogEventArgs e);

public class SftpserverLogEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int LogLevel { get; }
  public string Message { get; }
  public string LogType { get; }
}
Public Event OnLog As OnLogHandler

Public Delegate Sub OnLogHandler(sender As Object, e As SftpserverLogEventArgs)

Public Class SftpserverLogEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property LogLevel As Integer
  Public ReadOnly Property Message As String
  Public ReadOnly Property LogType As String
End Class

Remarks

This event fires once for each log messages generated by the component. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the detail level of the message. Possible values are:

0 (None) No messages are logged.
1 (Info - Default) Informational events such as SSH handshake messages are logged.
2 (Verbose) Detailed data such as individual packet information is logged.
3 (Debug) Debug data including all relevant sent and received bytes are logged.

Message is the log message.

LogType is reserved for future use.

ConnectionId identifies the connection to which the log message applies.

ResolvePath Event (SFTPServer Component)

Fires when a client attempts to canonicalize a path.

Syntax

public event OnResolvePathHandler OnResolvePath;

public delegate void OnResolvePathHandler(object sender, SftpserverResolvePathEventArgs e);

public class SftpserverResolvePathEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string OriginalPath { get; }
  public int ControlFlags { get; }
  public string RealPath { get; set; }
  public int StatusCode { get; set; }
}
Public Event OnResolvePath As OnResolvePathHandler

Public Delegate Sub OnResolvePathHandler(sender As Object, e As SftpserverResolvePathEventArgs)

Public Class SftpserverResolvePathEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property OriginalPath As String
  Public ReadOnly Property ControlFlags As Integer
  Public Property RealPath As String
  Public Property StatusCode As Integer
End Class

Remarks

The ResolvePath event fires when an SFTP client sends an SSH_FXP_REALPATH request. The OriginalPath parameter will contain the path the client wants to canonicalize. ControlFlags can have one of the following values:

SSH_FXP_REALPATH_NO_CHECK (0x00000001)Server should not check if the path exists.
SSH_FXP_REALPATH_STAT_IF (0x00000002)Server should return the file/directory attributes if the path exists and is accessible, but should not fail otherwise.
SSH_FXP_REALPATH_STAT_ALWAYS (0x00000003)Server should return the file/directory attributes if the path exists and is accessible, otherwise fail with an error.

RealPath should be set to the resulting canonicalized path, and StatusCode should be set to indicate success or failure of the operation to the client.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

SetAttributes Event (SFTPServer Component)

Fires when a client attempts to set file or directory attributes.

Syntax

public event OnSetAttributesHandler OnSetAttributes;

public delegate void OnSetAttributesHandler(object sender, SftpserverSetAttributesEventArgs e);

public class SftpserverSetAttributesEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Path { get; }
  public int FileType { get; }
  public long FileSize { get; }
  public string FileOwner { get; }
  public string FileGroup { get; }
  public int FilePermissions { get; }
  public long FileATime { get; }
  public long FileCreateTime { get; }
  public long FileMTime { get; }
  public int FileAttribBits { get; }
  public int FileAttribBitsValid { get; }
  public string OtherAttributes { get; }
  public bool BeforeExec { get; }
  public int StatusCode { get; set; }
}
Public Event OnSetAttributes As OnSetAttributesHandler

Public Delegate Sub OnSetAttributesHandler(sender As Object, e As SftpserverSetAttributesEventArgs)

Public Class SftpserverSetAttributesEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Path As String
  Public ReadOnly Property FileType As Integer
  Public ReadOnly Property FileSize As Long
  Public ReadOnly Property FileOwner As String
  Public ReadOnly Property FileGroup As String
  Public ReadOnly Property FilePermissions As Integer
  Public ReadOnly Property FileATime As Long
  Public ReadOnly Property FileCreateTime As Long
  Public ReadOnly Property FileMTime As Long
  Public ReadOnly Property FileAttribBits As Integer
  Public ReadOnly Property FileAttribBitsValid As Integer
  Public ReadOnly Property OtherAttributes As String
  Public ReadOnly Property BeforeExec As Boolean
  Public Property StatusCode As Integer
End Class

Remarks

The SetAttributes event fires when an SFTP client sends an SSH_FXP_SETSTAT, SSH_FXP_FSETSTAT or SSH_FXP_FSTAT request. Path is the path of the file or directory the client wants to set attributes for.

This event is fired both before and after the attributes are set. The BeforeExec parameter is True before the operation has been executed and False otherwise. Handling this event before execution of the operation provides an opportunity to add custom logic that may prevent or deny the operation. Handling this event after execution of the operation provides an opportunity to report any errors that may have occurred during the operation.

File/Directory Attributes are specified using the following values:

FileType: The type of file. Can be one of the following values:

  • SSH_FILEXFER_TYPE_REGULAR (1)
  • SSH_FILEXFER_TYPE_DIRECTORY (2)
  • SSH_FILEXFER_TYPE_SYMLINK (3)
  • SSH_FILEXFER_TYPE_SPECIAL (4)
  • SSH_FILEXFER_TYPE_UNKNOWN (5)
  • SSH_FILEXFER_TYPE_SOCKET (6)
  • SSH_FILEXFER_TYPE_CHAR_DEVICE (7)
  • SSH_FILEXFER_TYPE_BLOCK_DEVICE (8)
  • SSH_FILEXFER_TYPE_FIFO (9)

FileSize: The file size, in bytes.

FileOwner: The file owner. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like user identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FileGroup: The file owner group. If the ProtocolVersion configuration option is "3" (default), this field should be a numeric Unix-like group identifier. V4-V6 of the SFTP Protocol allow an arbitrary string.

FilePermissions: The POSIX-style file permissions.

FileATime: The file last-access time, in milliseconds since Jan 1, 1970 in UTC.

FileCreateTime: The file creation time, in milliseconds since Jan 1, 1970 in UTC.

FileMTime: The file last-modified time, in milliseconds since Jan 1, 1970 in UTC.

FileAttrBits: The file attributes, as a combination of the following values:

  • SSH_FILEXFER_ATTR_FLAGS_READONLY (0x00000001)
  • SSH_FILEXFER_ATTR_FLAGS_SYSTEM (0x00000002)
  • SSH_FILEXFER_ATTR_FLAGS_HIDDEN (0x00000004)
  • SSH_FILEXFER_ATTR_FLAGS_CASE_INSENSITIVE (0x00000008)
  • SSH_FILEXFER_ATTR_FLAGS_ARCHIVE (0x00000010)
  • SSH_FILEXFER_ATTR_FLAGS_ENCRYPTED (0x00000020)
  • SSH_FILEXFER_ATTR_FLAGS_COMPRESSED (0x00000040)
  • SSH_FILEXFER_ATTR_FLAGS_SPARSE (0x00000080)
  • SSH_FILEXFER_ATTR_FLAGS_APPEND_ONLY (0x00000100)
  • SSH_FILEXFER_ATTR_FLAGS_IMMUTABLE (0x00000200)
  • SSH_FILEXFER_ATTR_FLAGS_SYNC (0x00000400)
  • SSH_FILEXFER_ATTR_FLAGS_TRANSLATION_ERR (0x00000800)

FileAttrBitsValid: A mask specifying which bits in FileAttrBits are supported by the server.

OtherAttributes: A semi-colon (';') delimited list of Name=Value pairs of other attributes supported by SFTP. These include:

  • MIMEType (String)
  • AllocationSize (64-bit int)
  • ATimeNS (int): ATime nanoseconds
  • CreateTimeNS (int): CreateTime nanoseconds
  • MTimeNS (int): MTime nanoseconds
  • TextHint (8-bit int)
  • LinkCount (int)
  • UntranslatedName (String)

FileMimeType: The MIME type of the file.

Valid status codes are:

  • SSH_FX_OK 0
  • SSH_FX_EOF 1
  • SSH_FX_NO_SUCH_FILE 2
  • SSH_FX_PERMISSION_DENIED 3
  • SSH_FX_FAILURE 4
  • SSH_FX_BAD_MESSAGE 5
  • SSH_FX_NO_CONNECTION 6
  • SSH_FX_CONNECTION_LOST 7
  • SSH_FX_OP_UNSUPPORTED 8
  • SSH_FX_INVALID_HANDLE 9
  • SSH_FX_NO_SUCH_PATH 10
  • SSH_FX_FILE_ALREADY_EXISTS 11
  • SSH_FX_WRITE_PROTECT 12
  • SSH_FX_NO_MEDIA 13
  • SSH_FX_NO_SPACE_ON_FILESYSTEM 14
  • SSH_FX_QUOTA_EXCEEDED 15
  • SSH_FX_UNKNOWN_PRINCIPAL 16
  • SSH_FX_LOCK_CONFLICT 17
  • SSH_FX_DIR_NOT_EMPTY 18
  • SSH_FX_NOT_A_DIRECTORY 19
  • SSH_FX_INVALID_FILENAME 20
  • SSH_FX_LINK_LOOP 21
  • SSH_FX_CANNOT_DELETE 22
  • SSH_FX_INVALID_PARAMETER 23
  • SSH_FX_FILE_IS_A_DIRECTORY 24
  • SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
  • SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
  • SSH_FX_DELETE_PENDING 27
  • SSH_FX_FILE_CORRUPT 28
  • SSH_FX_OWNER_INVALID 29
  • SSH_FX_GROUP_INVALID 30
  • SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31

SSHStatus Event (SFTPServer Component)

Shows the progress of the secure connection.

Syntax

public event OnSSHStatusHandler OnSSHStatus;

public delegate void OnSSHStatusHandler(object sender, SftpserverSSHStatusEventArgs e);

public class SftpserverSSHStatusEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string Message { get; }
}
Public Event OnSSHStatus As OnSSHStatusHandler

Public Delegate Sub OnSSHStatusHandler(sender As Object, e As SftpserverSSHStatusEventArgs)

Public Class SftpserverSSHStatusEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Message As String
End Class

Remarks

The event is fired for informational and logging purposes only. Used to track the progress of the connection.

SSHUserAuthRequest Event (SFTPServer Component)

Fires when a client attempts to authenticate a connection.

Syntax

public event OnSSHUserAuthRequestHandler OnSSHUserAuthRequest;

public delegate void OnSSHUserAuthRequestHandler(object sender, SftpserverSSHUserAuthRequestEventArgs e);

public class SftpserverSSHUserAuthRequestEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string User { get; }
  public string Service { get; }
  public string AuthMethod { get; }
  public string AuthParam { get; }
  public bool Accept { get; set; }
  public bool PartialSuccess { get; set; }
  public string AvailableMethods { get; set; }
  public string HomeDir { get; set; }
  public string KeyAlgorithm { get; }
}
Public Event OnSSHUserAuthRequest As OnSSHUserAuthRequestHandler

Public Delegate Sub OnSSHUserAuthRequestHandler(sender As Object, e As SftpserverSSHUserAuthRequestEventArgs)

Public Class SftpserverSSHUserAuthRequestEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property User As String
  Public ReadOnly Property Service As String
  Public ReadOnly Property AuthMethod As String
  Public ReadOnly Property AuthParam As String
  Public Property Accept As Boolean
  Public Property PartialSuccess As Boolean
  Public Property AvailableMethods As String
  Public Property HomeDir As String
  Public ReadOnly Property KeyAlgorithm As String
End Class

Remarks

The SSHUserAuthRequest event fires when an SSH client attempts to authenticate itself on a particular connection. ConnectionId will identify the connection being authenticated. User will be the name of the account requesting authentication, and Service will contain the name of the service the client is wishing to access.

AuthMethod will denote which method the client is attempting to use to authenticate itself. AuthParam will contain the value of the authentication token used by the client. If the token is acceptable, you may set Accept to true to allow the SFTPServer to authenticate the client. If it is not, set Accept to false.

Connecting clients will initially attempt authentication with an AuthMethod of "none". This is done with the expectation that the request will fail and the server will send a list of supported methods back to the client. In your implementation check the AuthMethod parameter, if it is "none" you should set AvailableMethods and reject the request. The client will select one of the available methods and re-authenticate.

You may set AvailableMethods to a comma-delimited string of authentication methods that are available for the user. This list will be sent back to the client so that it may perform further authentication attempts.

The following is a list of methods implemented by the component:

noneThis authentication method is used by most SSH clients to obtain the list of authentication methods available for the user's account. In most cases you should not accept a request using this authentication method.
passwordAuthParam will contain the user-supplied password. If the password is correct, set Accept to true.
publickeyAuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept to true. The component will then handle verifying the digital signature and will respond to the client accordingly.
keyboard-interactiveSSHUserAuthRequest will fire multiple times for keyboard-interactive authentication: It will fire once for each response sent by the client in the SSH_MSG_USERAUTH_INFO_RESPONSE packet (one for each prompt specified by the daemon). The index of each response will be specified as a suffix in AuthMethod, with AuthParam containing the response to the corresponding prompt (e.g keyboard-interactive-1, keyboard-interactive-2 and so on). Finally, SSHUserAuthRequest will fire one last time with AuthMethod set to "keyboard-interactive" and AuthParam set to an empty string. The daemon must set Accept to true every time to allow the authentication process to succeed.

In the case the user authentication succeeds, you may set HomeDir to the virtual path representing the initial directory for the user. If not set, the initial directory will be RootDirectory.

The PartialSuccess parameter is only used when multi-factor authentication is needed. To implement multi-factor authentication when this event fires first verify the AuthParam for the given AuthMethod. If accepted, set PartialSuccess to true and Accept to false. The client should then send the authentication request for a different form of authentication specified in AvailableMethods. You may continue to set PartialSuccess to true until all authentication requirements are satisfied. Once all requirements are satisfied set Accept to true.

KeyAlgorithm hold the signing algorithm used when the client attempts public key authentication. Possible values are:

  • ssh-rsa
  • rsa-sha2-256
  • rsa-sha2-512
  • ssh-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
  • x509v3-sign-rsa
  • x509v3-sign-dss

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

EffectiveDate
String

This is the date on which this certificate becomes valid. Before this date, it is not valid. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

Encoded
String

This is the certificate (PEM/base64 encoded). This field is used to assign a specific certificate. The Store and Subject fields also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

EncodedB
Byte []

This is the certificate (PEM/base64 encoded). This field is used to assign a specific certificate. The Store and Subject fields also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

ExpirationDate
String

This is the date the certificate expires. After this date, the certificate will no longer be valid. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

ExtendedKeyUsage
String

This is a comma-delimited list of extended key usage identifiers. These are the same as ASN.1 object identifiers (OIDs).

Fingerprint
String

This is the hex-encoded, 16-byte MD5 fingerprint of the certificate.

The following example illustrates the format: bc:2a:72:af:fe:58:17:43:7a:5f:ba:5a:7c:90:f7:02

FingerprintSHA1
String

This is the hex-encoded, 20-byte SHA-1 fingerprint of the certificate.

The following example illustrates the format: 30:7b:fa:38:65:83:ff:da:b4:4e:07:3f:17:b8:a4:ed:80:be:ff:84

FingerprintSHA256
String

This is the hex-encoded, 32-byte SHA-256 fingerprint of the certificate.

The following example illustrates the format: 6a:80:5c:33:a9:43:ea:b0:96:12:8a:64:96:30:ef:4a:8a:96:86:ce:f4:c7:be:10:24:8e:2b:60:9e:f3:59:53

Issuer
String

This is the issuer of the certificate. This field contains a string representation of the name of the issuing authority for the certificate.

PrivateKey
String

This is the private key of the certificate (if available). The key is provided as PEM/Base64-encoded data.

Note: The PrivateKey may be available but not exportable. In this case, PrivateKey returns an empty string.

PrivateKeyAvailable
Boolean

This field shows whether a PrivateKey is available for the selected certificate. If PrivateKeyAvailable is True, the certificate may be used for authentication purposes (e.g., server authentication).

PrivateKeyContainer
String

This is the name of the PrivateKey container for the certificate (if available). This functionality is available only on Windows platforms.

PublicKey
String

This is the public key of the certificate. The key is provided as PEM/Base64-encoded data.

PublicKeyAlgorithm
String

This field contains the textual description of the certificate's public key algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_DH") or an object identifier (OID) string representing the algorithm.

PublicKeyLength
Integer

This is the length of the certificate's public key (in bits). Common values are 512, 1024, and 2048.

SerialNumber
String

This is the serial number of the certificate encoded as a string. The number is encoded as a series of hexadecimal digits, with each pair representing a byte of the serial number.

SignatureAlgorithm
String

The field contains the text description of the certificate's signature algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_MD5RSA") or an object identifier (OID) string representing the algorithm.

Store
String

This is the name of the certificate store for the client certificate.

The StoreType field denotes the type of the certificate store specified by Store. If the store is password protected, specify the password in StorePassword.

Store is used in conjunction with the Subject field to specify client certificates. If Store has a value, and Subject or Encoded is set, a search for a certificate is initiated. Please see the Subject field for details.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

StoreB
Byte []

This is the name of the certificate store for the client certificate.

The StoreType field denotes the type of the certificate store specified by Store. If the store is password protected, specify the password in StorePassword.

Store is used in conjunction with the Subject field to specify client certificates. If Store has a value, and Subject or Encoded is set, a search for a certificate is initiated. Please see the Subject field for details.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

StorePassword
String

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

StoreType
CertStoreTypes

This is the type of certificate store for this certificate.

The component supports both public and private keys in a variety of formats. When the cstAuto value is used the component will automatically determine the type. This field can take one of the following values:

0 (cstUser - default)For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note: this store type is not available in Java.
1 (cstMachine)For Windows, this specifies that the certificate store is a machine store. Note: this store type is not available in Java.
2 (cstPFXFile)The certificate store is the name of a PFX (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) format.
4 (cstJKSFile)The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: this store type is only available in Java.
5 (cstJKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in Java Key Store (JKS) format. Note: this store type is only available in Java.
6 (cstPEMKeyFile)The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 (cstPEMKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a private key and an optional certificate.
8 (cstPublicKeyFile)The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate.
9 (cstPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a PEM- or DER-encoded public key certificate.
10 (cstSSHPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains an SSH-style public key.
11 (cstP7BFile)The certificate store is the name of a PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 format.
13 (cstSSHPublicKeyFile)The certificate store is the name of a file that contains an SSH-style public key.
14 (cstPPKFile)The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 (cstPPKBlob)The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 (cstXMLFile)The certificate store is the name of a file that contains a certificate in XML format.
17 (cstXMLBlob)The certificate store is a string that contains a certificate in XML format.
18 (cstJWKFile)The certificate store is the name of a file that contains a JWK (JSON Web Key).
19 (cstJWKBlob)The certificate store is a string that contains a JWK (JSON Web Key).
20 (cstSecurityKey)The certificate is present on a physical security key accessible via a PKCS11 interface.

To use a security key the necessary data must first be collected using the CertMgr component. The ListStoreCertificates method may be called after setting CertStoreType to cstSecurityKey, CertStorePassword to the PIN, and CertStore to the full path of the PKCS11 dll. The certificate information returned in the CertList event's CertEncoded parameter may be saved for later use.

When using a certificate, pass the previously saved security key information as the Store and set StorePassword to the PIN.

Code Example: SSH Authentication with Security Key certmgr.CertStoreType = CertStoreTypes.cstSecurityKey; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstSecurityKey, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

21 (cstBCFKSFile)The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). Note: this store type is only available in Java and .NET.
22 (cstBCFKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. Note: this store type is only available in Java and .NET.
99 (cstAuto)The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically.

Subject
String

This is the subject of the certificate used for client authentication.

This field will be populated with the full subject of the loaded certificate. When loading a certificate the subject is used to locate the certificate in the store.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma separated list of distinguished name fields and values. For instance "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are displayed below.

FieldMeaning
CNCommon Name. This is commonly a host name like www.server.com.
OOrganization
OUOrganizational Unit
LLocality
SState
CCountry
EEmail Address

If a field value contains a comma it must be quoted.

SubjectAltNames
String

This field contains comma-separated lists of alternative subject names for the certificate.

ThumbprintMD5
String

This field contains the MD5 hash of the certificate. If the hash does not already exist, it is computed.

ThumbprintSHA1
String

This field contains the SHA-1 hash of the certificate. If the hash does not already exist, it is computed.

ThumbprintSHA256
String

This field contains the SHA-256 hash of the certificate. If the hash does not already exist, it is computed.

Usage
String

This field contains the text description of UsageFlags.

This value will be of one or more of the following strings and will be separated by commas:

  • Digital Signatures
  • Key Authentication
  • Key Encryption
  • Data Encryption
  • Key Agreement
  • Certificate Signing
  • Key Signing

If the provider is OpenSSL, the value is a comma-separated list of X.509 certificate extension names.

UsageFlags
Integer

This field contains the flags that show intended use for the certificate. The value of UsageFlags is a combination of the following flags:

0x80Digital Signatures
0x40Key Authentication
0x20Key Encryption
0x10Data Encryption
0x08Key Agreement
0x04Certificate Signing
0x02Key Signing

Please see the Usage field for a text representation of UsageFlags.

This functionality currently is not available when the provider is OpenSSL.

Version
String

This field contains the certificate's version number. The possible values are the strings "V1", "V2", and "V3".

Constructors

public Certificate();
Public Certificate()

Creates a Certificate instance whose properties can be set. This is useful for use with CERTMGR when generating new certificates.

public Certificate( certificateFile);
Public Certificate(ByVal CertificateFile As )

Opens CertificateFile and reads out the contents as an X509 public key.

public Certificate( certificateData);
Public Certificate(ByVal CertificateData As Byte())

Parses CertificateData as an X509 public key.

public Certificate( certStoreType,  store,  storePassword,  subject);
Public Certificate(ByVal CertStoreType As , ByVal Store As , ByVal StorePassword As , ByVal Subject As )

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  store,  storePassword,  subject,  configurationString);
Public Certificate(ByVal CertStoreType As , ByVal Store As , ByVal StorePassword As , ByVal Subject As , ByVal ConfigurationString As )

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. ConfigurationString is a newline separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CyrptoAPI option. The default value is True (the key is persisted). "Thumbprint" - a MD5, SHA1, or SHA256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to cstUser, cstMachine, cstPublicKeyFile, and cstPFXFile store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  store,  storePassword,  encoded);
Public Certificate(ByVal CertStoreType As , ByVal Store As , ByVal StorePassword As , ByVal Encoded As Byte())

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

public Certificate( certStoreType,  storeBlob,  storePassword,  subject);
Public Certificate(ByVal CertStoreType As , ByVal StoreBlob As Byte(), ByVal StorePassword As , ByVal Subject As )

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  storeBlob,  storePassword,  subject,  configurationString);
Public Certificate(ByVal CertStoreType As , ByVal StoreBlob As Byte(), ByVal StorePassword As , ByVal Subject As , ByVal ConfigurationString As )

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  storeBlob,  storePassword,  encoded);
Public Certificate(ByVal CertStoreType As , ByVal StoreBlob As Byte(), ByVal StorePassword As , ByVal Encoded As Byte())

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a string (binary- or base64-encoded) containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

SFTPConnection Type

A currently connected client.

Remarks

This type describes the connection of a client which is currently connected to the component. You may use the different fields of this type to manage the connection.

Fields

Connected
Boolean

Used to disconnect individual connections and/or show their status.

The Connected is used to close connections.

Connected also shows the status of a particular connection (connected/disconnected).

How and when the connection is closed is controlled by the Linger property. Please refer to its description for more information.

Note:It is recommended to use the Disconnect method instead of setting this property.

ConnectionId
String

An id generated by the component to identify each connection. This id is unique to this connection.

ErrorMessage
String

ErrorMessage is used together with status codes returned from events to send informative errors back to the SFTP client through the SSH_FXP_STATUS message. If left blank, the component will set a default message based on the returned status code.

FileData
String

The FileData should be set or read when processing read/write file events.

FileDataB
Byte []

The FileData should be set or read when processing read/write file events.

LocalAddress
String

This field shows the IP address of the interface through which the connection is passing.

LocalAddress is important for multihomed hosts where it can be used to find which particular network interface an individual connection is going through.

ProtocolVersion
Integer

The ProtocolVersion shows the SFTP protocol version negotiated with the client when the SFTP connection was established.

RemoteHost
String

The RemoteHost shows the IP address of the remote host through which the connection is coming.

The connection must be valid or an error will be fired.

If the component is configured to use a SOCKS firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution.

RemotePort
Integer

The RemotePort shows the TCP port on the remote host through which the connection is coming.

The connection must be valid or an error will be fired.

Timeout
Integer

A timeout for the component.

If the Timeout field is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If Timeout is set to a positive value, the component will wait for the operation to complete before returning control.

The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the component throws an exception.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for Timeout is specified by the DefaultTimeout property.

Constructors

public SFTPConnection();
Public SFTPConnection()

SSHPrompt Type

A prompt to provide to the client during keyboard-interactive authentication.

Remarks

This type describes a prompt the SSH daemon will send to the client when requesting keyboard-interactive authentication.

Fields

Echo
Boolean

Specifies if the client should echo the value entered by the user or not.

Prompt
String

The prompt label/text the client should present to the user.

Constructors

public SSHPrompt();
Public SSHPrompt()
public SSHPrompt( prompt,  echo);
Public SSHPrompt(ByVal Prompt As , ByVal Echo As )

Config Settings (SFTPServer Component)

The component accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

SFTPServer Config Settings

DirListBufferSize[ConnectionId]:   The number of entries to be returned in one response to a request for a directory listing.

The default value for this configuration setting is 1, which means that the component will return one entry at a time in response to a request for a directory listing. Changing this value will allow the component to bundle multiple entries into a single response.

MaskSensitive:   Masks passwords in logs.

The default value is False. When set to True, the component will mask passwords that otherwise would appear in its logs.

ProtocolVersion:   The highest allowable SFTP version to use.

This governs the highest allowable SFTP version to use when negotiating the version with the client. The default value is 3 as this is the most common version. The component supports values from 3 to 6.

ResolveOwnerAndGroup[ConnectionId]:   Whether to automatically determine the FileOwner and FileGroup.

When set to True (default), this configuration setting will allow the component to determine the user name from the Unix-like user identifier, and the group name from the Unix-like group identifier. When set to False, the component will return the Unix-like user and group identifiers instead.

NOTE: This functionality is not available in Mono.

RestrictUserToHomeDir[ConnectionId]:   Whether to restrict the user to their home directory.

When True, this setting will restrict the user to the path specified by the "HomeDir" parameter in the SSHUserAuthRequest event. When False (default), the user will be able to navigate outside of the home directory. "ConnectionId" specifies the connection to which the restriction applies.

sftpserver.Config("RestrictUserToHomeDir[" + e.ConnectionId + "]=true");

Example

If the RootDirectory property of a certain SFTP server is set to /, then the directory structure of the server might look like this...

Root Directory: /

bin
boot
etc
home
  user1
    testfolder
When RestrictUserToHomeDir is set to True and the "HomeDir" parameter is set to /home/user1, User 1 will land in the home directory and see the following file system when it connects:
Home Directory: /home/user1

/testfolder
The client will only be able to perform operations against /home/user1 and its children but the client can see its working directory relative to the server root directory.

ServerEOL:   Specifies the line endings used in files on the server.

This setting is used to inform the connecting client what line endings are used in the files on the system. This is only applicable when ProtocolVersion is set to 4 or higher and a connecting client negotiates protocol version 4 or higher. When a client negotiates version 4 or higher this value is reported using the "newline" protocol convention. The client may use that to transform line endings when downloading. The default value is CrLF.

SFTPErrorMessage[ConnectionId]:   Specifies the error message to be returned to the client.

If an SFTP operation would return an error to the client (e.g., permission denied, file does not exist, etc) then this configuration option can be used to specify the error message to be returned to the client. This configuration option is only effective when set within an event that uses the "StatusCode" field.

UserRootDirectory[ConnectionId]:   The path of the server root directory for a particular user.

When set to a subdirectory of the server root, this setting will override the server RootDirectory for a particular user. The "HomeDir" parameter of the SSHUserAuthRequest event will represent the initial path of the client relative to the UserRootDirectory. "ConnectionId" specifies the connection to which the restriction applies. sftpserver.Config("UserRootDirectory[" + e.ConnectionId + "]=" + userRootDirectory );

Example

If the RootDirectory property of a certain SFTP server is set to /, then the directory structure of the server might look like this...

Root Directory: /

bin
boot
etc
home
  user1
    testfolder
When UserRootDirectory is set to /home/user1 and the HomeDir event parameter is set to /, when User 1 connects they will land in the home directory and see the following file system:
Home Directory: /

/testfolder
The client will only be able to perform operations against / and its children and the client cannot see its working directory relative to the server root directory.

SSHServer Config Settings

AltSSHCertCount:   The number of records in the AltSSHCert configuration settings.

This configuration setting controls the size of the following arrays:

The array indices start at 0 and end at AltSSHCertCount - 1.

The AltSSHCert configuration settings are used to specify alternative digital certificates to the one set using the SSHCert. The server will determine the certificate to use during SSH negotiation based on the public key algorithm requested by the connecting client. A certificate with a private key is required for session authentication and encryption.

These are the server's certificates, and must be set prior to setting Listening to True.

AltSSHCertStore[i]:   The name of the certificate store.

The name of the certificate store. This is used when specifying an alternative SSHCert.

The AltSSHCertStoreType specifies the type of the certificate store specified by AltSSHCertStore. IF the store is password protected, specify the password in the AltSSHCertStorePassword.

AltSSHCertStore is used in conjunction with the AltSSHCertSubject field in order to specify the certificate.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

AltSSHCertStorePassword[i]:   The password used to open the certificate store.

If the certificate store is of a type that requires a password, this setting can be used to specify that password. This is used when specifying an alternative SSHCert

AltSSHCertStoreType[i]:   The type of certificate store.

This specifies the type of certificate store. This is used when specifying an alternate SSHCert. Possible values are:

0 User - default For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note: this store type is not available in Java.
1 Machine - For Windows, this specifies that the certificate store is a machine store. Note: this store type is not available in Java.
2 PFXFile - The certificate store is the name of a PFX (PKCS12) file containing certificates.
3 PFXBlob - The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) format.
4 JKSFile - The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: this store type is only available in Java.
5 JKSBlob - The certificate store is a string (binary or base64-encoded) representing a certificate store in Java Key Store (JKS) format. Note: this store type is only available in Java.
6 PEMKeyFile - The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 PEMKeyBlob - The certificate store is a string (binary or base64-encoded) that contains a private key and an optional certificate.
14 PPKFile - The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 PPKBlob - The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 XMLFile - The certificate store is the name of a file that contains a certificate in XML format.
17 XMLBlob - The certificate store is a string that contains a certificate in XML format.

AltSSHCertSubject[i]:   The alternative certificate subject.

The subject of the certificate. This is used when specifying an alternative SSHCert.

KeyboardInteractivePrompts[ConnectionId]:   Specifies custom keyboard-interactive prompts for particular connections.

By default, setting the KeyboardInteractivePrompts property will cause those prompts to be used for every user attempting to connect. This setting can be used to override the KeyboardInteractivePrompts property and provide unique prompts for certain connections.

This setting takes a list of prompts to display to the client, and each prompt includes an 'echo' parameter to specify whether or not to echo the client's response to the prompt. The prompt itself and the echo parameter should be separated by a comma (","), and each prompt should be separated by a semi-colon (";"). For example:

"KeyboardInteractivePrompts[connId]=First prompt,echo=false;Second prompt,echo=true"

This config can be set anywhere in code, but it is necessary to know the ConnectionId for the specific connection beforehand; as such, it is generally recommended to set this config inside the SSHUserAuthRequest event. Since connecting clients initially attempt to connect with and AuthMethod of 'none' (with the understanding that this attempt will fail, and the SSH server will advertise which authentication methods it supports), It is recommended to check the AuthMethod, User, and ConnectionId parameters of the SSHUserAuthRequest event and set this config accordingly.

When SSHServer displays keyboard-interactive prompts, it will first check to see if this config is populated for the current ConnectionId. If it is, the prompts set here will be used instead of those set in the KeyboardInteractivePrompts property. Otherwise, the KeyboardInteractivePrompts property will function as normal.

KeyRenegotiationThreshold:   Sets the threshold for the SSH Key Renegotiation.

This property allows you to specify the threshold, in the number of bytes, for the SSH Key Renegotiation. The default value for this property is set to 1 GB.

Example (for setting the threshold to 500 MB): SSHComponent.Config("KeyRenegotiationThreshold=524288000")

LogLevel:   Specifies the level of detail that is logged.

This setting controls the level of detail that is logged through the Log event. Possible values are:

0 (None) No messages are logged.
1 (Info - Default) Informational events such as SSH handshake messages are logged.
2 (Verbose) Detailed data such as individual packet information is logged.
3 (Debug) Debug data including all relevant sent and received bytes are logged.

MaxAuthAttempts:   The maximum authentication attempts allowed before forcing a disconnect.

This setting specifies the maximum amount of authentication attempts that will be allowed before forcibly disconnecting the client.

ServerSSHVersionString:   The SSH version string sent to connecting clients.

This setting specifies the version string value that is sent to all connecting clients. This may be set to specify server specific information. The default value is "SSH-2.0-IPWorks SSH Daemon 2016". When setting your own value it must begin with "SSH-2.0-" as this is a standard format that specifies the supported SSH version.

SSHKeepAliveCountMax:   The maximum number of keep alive packets to send without a response.

This setting specifies the maximum number of keep alive packets to send when no response is received. Normally a response to a keep alive packet is received right away. If no response is received the component will continue to send keep alive packets until SSHKeepAliveCountMax is reached. If this is reached the component will assume the connection is broken and disconnect. The default value is 5.

SSHKeepAliveInterval:   The interval between keep alive packets.

This setting specifies the number of seconds between keep alive packets. If set to a positive value the component will send a SSH keep alive packet after KeepAliveInterval seconds of inactivity. This setting only takes effect when there is no activity, if any data is sent or received over the connection it will reset the timer.

The default value is 0 meaning no keep alives will be sent.

Note: The SSHReverseTunnel component uses a default value of 30.

SSHKeyExchangeAlgorithms:   Specifies the supported key exchange algorithms.

This may be used to specify the list of supported Key Exchange algorithms used during SSH negotiation. The value should contain a comma separated list of algorithms. Supported algorithms are:

  • curve25519-sha256
  • curve25519-sha256@libssh.org
  • diffie-hellman-group1-sha1
  • diffie-hellman-group14-sha1
  • diffie-hellman-group14-sha256
  • diffie-hellman-group16-sha512
  • diffie-hellman-group18-sha512
  • diffie-hellman-group-exchange-sha256
  • diffie-hellman-group-exchange-sha1
  • ecdh-sha2-nistp256
  • ecdh-sha2-nistp384
  • ecdh-sha2-nistp521
The default value is: curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1.
SSHMacAlgorithms:   Specifies the supported Mac algorithms.

This may be used to specify an alternate list of supported Mac algorithms used during SSH negotiation. This also specifies the order in which the Mac algorithms are preferred. The value should contain a comma separated list of algorithms. Supported algorithms are:

  • hmac-sha1
  • hmac-md5
  • hmac-sha1-96
  • hmac-md5-96
  • hmac-sha2-256
  • hmac-sha2-256-96
  • hmac-sha2-512
  • hmac-sha2-512-96
  • hmac-ripemd160
  • hmac-ripemd160-96
  • hmac-sha2-256-etm@openssh.com
  • hmac-sha2-512-etm@openssh.com
The default value is hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5,hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256-96,hmac-sha2-512-96,hmac-ripemd160-96,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com.
SSHPubKeyAuthSigAlgorithms:   Specifies the allowed signature algorithms used by a client performing public key authentication.

This setting specifies a list of signature algorithms that a client is allowed to use when authenticating to the server using public key authentication. This applies only when public key authentication is performed by the client.

The setting should be a comma separated list of algorithms. When a client connects the server will verify that the client performing public key authentication has used one of the specified signature algorithms. If the client uses a signature algorithm which is not in the list the connection will be rejected.

Possible values are:

  • ssh-rsa
  • rsa-sha2-256
  • rsa-sha2-512
  • ssh-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
  • ssh-ed25519
  • x509v3-sign-rsa
  • x509v3-sign-dss

The default value in Windows is ssh-rsa,rsa-sha2-256,rsa-sha2-512,x509v3-sign-rsa,ssh-dss,x509v3-sign-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519.

SSHPublicKeyAlgorithms:   Specifies the supported public key algorithms for the server's public key.

This setting specifies the allowed public key algorithms for the server's public key. This list controls only the public key algorithm used when authenticating the server's public key. This list has no bearing on the public key algorithms that can be used by the client when performing public key authentication to the server. The default value is ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-256,rsa-sha2-512,ssh-rsa,ssh-dss,x509v3-sign-rsa,x509v3-sign-dss.

SSHVersionPattern:   The pattern used to match the remote host's version string.

This configuration setting specifies the pattern used to accept or deny the remote host's SSH version string. It takes a comma-delimited list of patterns to match. The default value is "*SSH-1.99-*,*SSH-2.0-*" and will accept connections from SSH 1.99 and 2.0 hosts. As an example, the below value would accept connections for SSH 1.99, 2.0, and 2.99 hosts.

*SSH-1.99-*,*SSH-2.0-*,*SSH-2.99-*
UserAuthBanner[ConnectionId]:   A custom user authentication banner.

This setting specifies a custom user authentication banner, which may be sent to give the client more information regarding an authentication attempt. "connectionId" specifies the particular connection to send the message to. This configuration option is only effective when set within the SSHUserAuthRequest event.

TCPServer Config Settings

AllowedClients:   A comma-separated list of host names or IP addresses that can access the component.

This configuration setting defines a comma-separated list of host names or IPv4 addresses that may access the component. The wildcard character "*" is supported. The default value is "*" and all connections are accepted.

When a client connects, the client's address is checked against the list defined here. If there is no match, the ConnectionRequest event fires with an Accept value set to False. If no action is taken within the ConnectionRequest event, the client will be disconnected.

BindExclusively:   Whether or not the component considers a local port reserved for exclusive use.

If this is True (default), the component will bind to the local port with the ExclusiveAddressUse option set, meaning that nothing else can bind to the same port. Also the component will not be able to bind to local ports that are already in use by some other instance, and attempts to do so will result in failure.

CloseStreamAfterTransfer:   If true, the component will close the upload or download stream after the transfer.

This setting determines whether the input or output stream is closed after the transfer completes. When set to True (default), all streams will be closed after a transfer is completed. In order to keep streams open after the transfer of data, set this to False. the default value is True.

DefaultConnectionTimeout:   The inactivity timeout applied to the SSL handshake.

This configuration setting specifies the inactivity (in seconds) to apply to incoming Secure Sockets Layer (SSL) connections. When set to a positive value, if the other end is unresponsive for the specified number of seconds, the connection will timeout. This is not applicable to the entire handshake. It is applicable only to the inactivity of the connecting client during the handshake if a response is expected and none is received within the timeout window. The default value is 0, and no connection-specific timeout is applied.

Note: This is applicable only to incoming SSL connections. This should be set only if there is a specific reason to do so.

InBufferSize:   The size in bytes of the incoming queue of the socket.

This is the size of an internal queue in the Transmission Control Protocol (TCP)/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated, the InBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

InBufferSize is shared among incoming connections. When the property is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

KeepAliveInterval:   The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.

A TCP keep-alive packet will be sent after a period of inactivity, as defined by KeepAliveTime. If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. If this value is not specified here, the system default is 1 second. This setting is applicable to all connections.

Note: This value is not applicable in macOS.

KeepAliveTime:   The inactivity time in milliseconds before a TCP keep-alive packet is sent.

By default, the operating system will determine the time a connection is idle before a TCP keep-alive packet is sent. If this value is not specified here, the system default is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds. This setting is applicable to all connections.

MaxConnections:   The maximum number of connections available.

This is the maximum number of connections available. This property must be set before Listening is set to True, and once set, it can no longer be changed for the current instance of the component. The maximum value for this setting is 100,000 connections. Use this setting with caution. Extremely large values may affect performance.

OutBufferSize:   The size in bytes of the outgoing queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the OutBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

OutBufferSize is shared among incoming connections. When the property is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

PreferredDHGroupBits:   Size of the Diffie-Hellman group, in bits.

This configuration setting specifies the key length used by the Diffe-Hellman key algorithm. The default value is 2048 (bits).

TcpNoDelay:   Whether or not to delay when sending packets.

When true, the socket will send all data that is ready to send at once. When false, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm.

By default, this config is set to false.

UseBackgroundThread:   Whether threads created by the component are background threads.

If set to True, when the component creates a thread, the thread's IsBackground property will be explicitly set to True. By default, this setting is False.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the component will use IPv4 exclusively. When set to 1, the component will use IPv6 exclusively. When set to 2, the component will listen for both IPv4 and IPv6 connections. If IPv6 is not available on the system, only IPv4 will be used. The default value is 0. Possible values are as follows:

0 IPv4 Only
1 IPv6 Only
2 IPv6 and IPv4

Base Config Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable:   Tells the component whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
UseInternalSecurityAPI:   Tells the component whether or not to use the system security libraries or an internal implementation.

By default the component will use the system security libraries to perform cryptographic functions where applicable. When set to false calls to unmanaged code will be made. In certain environments this is not desirable. To use a completely managed security implementation set this setting to true. Setting this to true tells the component to use the internal implementation instead of using the system's security API.

Note: This setting is static. The value set is applicable to all components used in the application.

When this value is set the product's system DLL is no longer required as a reference, as all unmanaged code is stored in that file.

Trappable Errors (SFTPServer Component)

SFTPServer Errors

118   Firewall error. Error description contains detailed information.
2001   The specified path is invalid.
2002   An I/O error occurred.
2003   The file attributes could not be set.

The component may also return one of the following error codes, which are inherited from other components.

SSHServer Errors

1201   Could not forward connection. A detailed message follows.
1202   Could not forward connection/channel data. A detailed message follows.
1300   Could not authenticate client.
1301   No server certificate was specified or no private key found.

TCPServer Errors

100   You cannot change the RemotePort at this time. A connection is in progress.
101   You cannot change the RemoteHost at this time. A connection is in progress.
102   The RemoteHost address is invalid (0.0.0.0).
104   TCPServer is already listening.
106   Cannot change LocalPort when TCPServer is listening.
107   Cannot change LocalHost when TCPServer is listening.
108   Cannot change MaxConnections when TCPServer is listening.
112   You cannot change MaxLineLength at this time. A connection is in progress.
116   RemotePort cannot be zero. Please specify a valid service port number.
126   Invalid ConnectionId.
135   Operation would block.

TCP/IP Errors

10004   [10004] Interrupted system call.
10009   [10009] Bad file number.
10013   [10013] Access denied.
10014   [10014] Bad address.
10022   [10022] Invalid argument.
10024   [10024] Too many open files.
10035   [10035] Operation would block.
10036   [10036] Operation now in progress.
10037   [10037] Operation already in progress.
10038   [10038] Socket operation on non-socket.
10039   [10039] Destination address required.
10040   [10040] Message too long.
10041   [10041] Protocol wrong type for socket.
10042   [10042] Bad protocol option.
10043   [10043] Protocol not supported.
10044   [10044] Socket type not supported.
10045   [10045] Operation not supported on socket.
10046   [10046] Protocol family not supported.
10047   [10047] Address family not supported by protocol family.
10048   [10048] Address already in use.
10049   [10049] Can't assign requested address.
10050   [10050] Network is down.
10051   [10051] Network is unreachable.
10052   [10052] Net dropped connection or reset.
10053   [10053] Software caused connection abort.
10054   [10054] Connection reset by peer.
10055   [10055] No buffer space available.
10056   [10056] Socket is already connected.
10057   [10057] Socket is not connected.
10058   [10058] Can't send after socket shutdown.
10059   [10059] Too many references, can't splice.
10060   [10060] Connection timed out.
10061   [10061] Connection refused.
10062   [10062] Too many levels of symbolic links.
10063   [10063] File name too long.
10064   [10064] Host is down.
10065   [10065] No route to host.
10066   [10066] Directory not empty
10067   [10067] Too many processes.
10068   [10068] Too many users.
10069   [10069] Disc Quota Exceeded.
10070   [10070] Stale NFS file handle.
10071   [10071] Too many levels of remote in path.
10091   [10091] Network subsystem is unavailable.
10092   [10092] WINSOCK DLL Version out of range.
10093   [10093] Winsock not loaded yet.
11001   [11001] Host not found.
11002   [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
11003   [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
11004   [11004] Valid name, no data record (check DNS setup).

Copyright (c) 2022 /n software inc. - All rights reserved.
IPWorks SSH 2022 .NET Edition - Version 22.0 [Build 8304]