SSHClient Component

Properties   Methods   Events   Config Settings   Errors  

The SSHClient component provides client-side SSH protocol functionality

Syntax

nsoftware.SecureBlackbox.SSHClient

Remarks

Use SSHClient to establish terminal-like connections to remote systems and run commands remotely. The component supports most of third-party implementations out there, and is capable of working in "shell" and "command" modes.

Start with assigning your sign-in credentials to Username and Password properties. Where public key authentication is to be used, assign your private authentication key to Key property (remember to set Username in this case too). Subscribe to events to be notified of the session progress. AuthFailed, AuthSucceeded, and Connect are among those particularly useful.

Special attention should be paid to setting up the server key trust. Component only allows connections to servers whose public keys are recognized as trusted, much like any other SSH clients do. Assign a path to the file containing the list of trusted keys to TrustedKeysFile property. If you don't have such file, or if you would like to make trust decisions on the fly, subscribe to KnownKeyReceived and UnknownKeyReceived events. These are fired whenever a trusted or untrusted key is received from the server. For unknown/untrusted keys, you need to set the Action parameter in your UnknownKeyReceived event handler to catAcceptOnce (1) or catAcceptPermanently (2) for the connection to proceed.

Once you are all set up, you can go ahead by calling the Connect method. This launches the SSH handshake and, if everything has been set up right, establishes a connection to the server. You can now use Send and Receive methods to exchange information with the server. You can exchange data in synchronous or asynchronous way; see the description in AsyncMode topic to learn more about each mode.

When you are done with the session, call Disconnect to shut the connection down.

Hint: If you are only interested in a quick-and-dirty execution of a simple, non-interactive command, SSHClient offers a handy shortcut. ConnectAndExec method is a self-contained mechanism which sets up a connection, performs the data exchange internally, and returns the command output. Please keep in mind that you still need to set up the server trust settings as described above for this method to work.

Property List

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

Method List

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

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.

Config Settings

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

AsyncMode Property (SSHClient Component)

Controls the SSH clients mode of work.

Syntax

• C#
• VB.NET

public bool AsyncMode { get; set; }

Public Property AsyncMode As Boolean

Default Value

False

Remarks

This property defines the way in which the component communicates with the application/user code. AsyncMode set to false makes the component use synchronous single-thread approach. Synchronous mode is generally simpler to integrate and use, but please keep in mind that the calls like Connect, Receive or SendBytes may block until their execution completes. In asyncronous mode all operations return immediately, but more care should be taken about handling them in your code properly.

Here are a few highlights of each mode.

Synchronous mode:

• All operations are performed within the caller thread context
• Operations like Connect or SendBytes may block
• Use Poll to check for the availability of data before reading it out with Receive or ReceiveBytes
• Return of a call guarantees completion of the operation
• Connection errors are reported straight from the methods via exceptions

Asynchronous mode:

• All operations are performed in a separate thread (and so are the event calls!)
• Methods like Send return immediately
• Use DataSent and DataReceived events to be notified about actual data transmissions
• Return of call only marks the beginning of the operation and does not guarantee its successful completion
• Connection errors are reported via Error event, often followed by Disconnect.

Please note that this is a very important and sensitive property, which has a wide-scale effect on the way the SSH client works and co-operates with the application. Depending on the value assigned to this setting you may need to work with the component very differently.

When setting this property to true, please make sure that your code is prepared to handle events coming from the context of a different thread.

AuthAttempts Property (SSHClient Component)

Specifies the number of SSH password authentication attempts.

Syntax

• C#
• VB.NET

public int AuthAttempts { get; set; }

Public Property AuthAttempts As Integer

Default Value

1

Remarks

In case of password authentication failure provide new password inside the AuthFailed event handler.

Commands Property (SSHClient Component)

Specifies the list of commands to execute

Syntax

• C#
• VB.NET

public string Commands { get; set; }

Public Property Commands As String

Default Value

""

Remarks

Use this property to provide a list of commands to execute remotely. Separate different commands with EOL characters.

When this property is set, the component works in the command mode, meaning each command is executed in its own virtual terminal session. No shell connection is established.

If no commands are provided via this property, the component will establish a shell session.

Connected Property (SSHClient Component)

Specifies whether the client is connected to the SFTP server.

Syntax

• C#
• VB.NET

public bool Connected { get; }

Public ReadOnly Property Connected As Boolean

Default Value

False

Remarks

Use this read-only property to check whether the client is connected to the server.

This property is read-only.

ConnectionInfo Property (SSHClient Component)

Contains the secure connection info.

Syntax

• C#
• VB.NET

public SSHConnectionInfo ConnectionInfo { get; }

Public ReadOnly Property ConnectionInfo As SSHConnectionInfo

Remarks

This property contains various information about the secure connection.

This property is read-only.

ExitMessage Property (SSHClient Component)

Contains the last commands exit message

Syntax

• C#
• VB.NET

public string ExitMessage { get; }

Public ReadOnly Property ExitMessage As String

Default Value

""

Remarks

Use this property to access the exit message of the last command or shell session. This property normally gets assigned if the command or shell was closed due to an error.

This property is read-only and not available at design time.

ExitSignal Property (SSHClient Component)

Contains the last commands exit signal

Syntax

• C#
• VB.NET

public string ExitSignal { get; }

Public ReadOnly Property ExitSignal As String

Default Value

""

Remarks

Use this property to access the exit signal of the last command or shell session. This property normally gets assigned if the command or shell was closed due to an error.

This property is read-only and not available at design time.

ExitStatus Property (SSHClient Component)

Contains the last commands exit status.

Syntax

• C#
• VB.NET

public int ExitStatus { get; }

Public ReadOnly Property ExitStatus As Integer

Default Value

0

Remarks

Check this property to obtain the exit status (also sometimes referred to as errorlevel) of the last command or shell session.

This property is read-only and not available at design time.

ExternalCrypto Property (SSHClient Component)

Provides access to external signing and DC parameters.

Syntax

• C#
• VB.NET

public ExternalCrypto ExternalCrypto { get; }

Public ReadOnly Property ExternalCrypto As ExternalCrypto

Remarks

Use this property to tune-up remote cryptography settings. SecureBlackbox supports two independent types of external cryptography: synchronous (based on the ExternalSign event) and asynchronous (based on the DC protocol and the DCAuth signing component).

This property is read-only.

FIPSMode Property (SSHClient Component)

Reserved.

Syntax

• C#
• VB.NET

public bool FIPSMode { get; set; }

Public Property FIPSMode As Boolean

Default Value

False

Remarks

This property is reserved for future use.

Key Property (SSHClient Component)

Contains client's SSH key.

Syntax

• C#
• VB.NET

public SSHKey Key { get; set; }

Public Property Key As SSHKey

Remarks

Server's public key is returned by ServerKey property.

Password Property (SSHClient Component)

Specifies user's password on the server.

Syntax

• C#
• VB.NET

public string Password { get; set; }

Public Property Password As String

Default Value

""

Remarks

Invalid password fires the AuthFailed event.

Proxy Property (SSHClient Component)

Allows connection through a proxy server.

Syntax

• C#
• VB.NET

public ProxySettings Proxy { get; }

Public ReadOnly Property Proxy As ProxySettings

Remarks

Set this property if the connection should be established through a proxy server.

This property is read-only.

ServerKey Property (SSHClient Component)

Returns server's public key.

Syntax

• C#
• VB.NET

public SSHKey ServerKey { get; }

Public ReadOnly Property ServerKey As SSHKey

Remarks

Client's SSH key is specified by Key.

This property is read-only.

SocketSettings Property (SSHClient Component)

Manages network connection settings.

Syntax

• C#
• VB.NET

public SocketSettings SocketSettings { get; }

Public ReadOnly Property SocketSettings As SocketSettings

Remarks

Use this property to tune up network connection parameters.

This property is read-only.

SSHSettings Property (SSHClient Component)

Provides access to SSH connection settings.

Syntax

• C#
• VB.NET

public SSHSettings SSHSettings { get; }

Public ReadOnly Property SSHSettings As SSHSettings

Remarks

Use this property to configure SSH protocol settings.

This property is read-only.

Subsystem Property (SSHClient Component)

Specifies the subsystem to request from the server.

Syntax

• C#
• VB.NET

public string Subsystem { get; set; }

Public Property Subsystem As String

Default Value

""

Remarks

Subsystem is a special form of an SSH channel. It is typically used to transfer third-party protocol data, with SFTP being the most widely known.

You can tell component to set up a subsystem connection (rather than a shell or command) by assigning the subsystem name to this property.

Terminal Property (SSHClient Component)

Provides access to SSH terminal settings object

Syntax

• C#
• VB.NET

public SSHTerm Terminal { get; }

Public ReadOnly Property Terminal As SSHTerm

Remarks

Use this property to configure the pseudo-terminal parameters before opening a shell or command connection.

This property is read-only.

TrustedKeysFile Property (SSHClient Component)

Path to the file containing public keys of authorized servers.

Syntax

• C#
• VB.NET

public string TrustedKeysFile { get; set; }

Public Property TrustedKeysFile As String

Default Value

""

Remarks

Path to the file containing public keys of authorized servers.

Username Property (SSHClient Component)

Specifies client's username on the server.

Syntax

• C#
• VB.NET

public string Username { get; set; }

Public Property Username As String

Default Value

""

Remarks

Client's password is set by Password property. ;

Config Method (SSHClient Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Public Function Config(ByVal ConfigurationString As String) As 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.

Connect Method (SSHClient Component)

Establishes connection to an SSH server.

Syntax

• C#
• VB.NET

public void Connect(string address, int port);

Public Sub Connect(ByVal Address As String, ByVal Port As Integer)

Remarks

Use this method to connect to the SSH server by providing its Address and Port.

Before connecting to the server you might want to set up your credentials using Username and Password properties. You might also need to configure the server key validation routine. You can do this by subscribing to KnownKeyReceived and UnknownKeyReceived events and implementing the event handlers as required.

Adjust AsyncMode before connecting to switch the component to either synchronous or asynchronous mode. In synchronous mode, all the calls to the component, such as Connect or SendBytes, are executed within the context of the caller thread, and block until the action completes. In asynchronous mode, the component runs the SSH session in a background thread, which makes all such calls return immediately. Find out more about the modes in the AsyncMode topic.

ConnectAndExec Method (SSHClient Component)

Connects to an SSH server and executes a command in one go.

Syntax

• C#
• VB.NET

public byte[] ConnectAndExec(string address, int port, string command, bool wantStdout, bool wantStdErr);

Public Function ConnectAndExec(ByVal Address As String, ByVal Port As Integer, ByVal Command As String, ByVal WantStdout As Boolean, ByVal WantStdErr As Boolean) As Byte()

Remarks

Use this method to connect to an SSH server at Address and Port and execute a command. The method returns the output of the executed command.

This method is a handy shortcut for running non-interactive commands. It encapsulates calls to Connect, Receive, Disconnect internally to save you time and space.

Please note that ConnectAndExec always runs synchronously, thus ignoring the AsyncMode setting.

Disconnect Method (SSHClient Component)

Closes connection to the SSH server.

Syntax

• C#
• VB.NET

public void Disconnect();

Public Sub Disconnect()

Remarks

Call this method to terminate the active SSH connection.

Please note that in some cases the component may still have some inbound data cached internally even after the connection is closed. You can read that data out using Receive and/or ReceiveBytes methods.

DoAction Method (SSHClient Component)

Performs an additional action.

Syntax

• C#
• VB.NET

public string DoAction(string actionID, string actionParams);

Public Function DoAction(ByVal ActionID As String, ByVal ActionParams As String) As String

Remarks

DoAction is a generic method available in every component. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

Ping Method (SSHClient Component)

Sends a keep-alive request to the SSH server.

Syntax

• C#
• VB.NET

public void Ping();

Public Sub Ping()

Remarks

Use this method to send a keep-alive message to the SSH server. Keep-alive messages are empty data packets which carry no useful information but are a handy way of checking if the connection is still alive.

Poll Method (SSHClient Component)

Checks whether there is any inbound data readily available.

Syntax

• C#
• VB.NET

public bool Poll(int milliseconds);

Public Function Poll(ByVal Milliseconds As Integer) As Boolean

Remarks

Use this method to check whether there is any incoming data available in the connection. If this method returns true, you can read the data with Receive or ReceiveBytes calls.

Use the Milliseconds parameter to tell the component how long it can wait for the data to arrive.

Receive Method (SSHClient Component)

Reads a portion of received data into a string.

Syntax

• C#
• VB.NET

public string Receive();

Public Function Receive() As String

Remarks

Use this method to read out a piece of data received from the server into a string.

Note that in synchronous mode this method may block in the absence of any inbound data until the next piece of data is received from the server. Use Poll to check if there is any data in the connection that is immediately available for reading.

In asynchronous mode a good time to call this method is upon receiving a read notification in DataReceived event handler. When working in asynchronous mode, this call returns immediately.

This method only returns data that arrives via the stdout channel. Use ReceiveFrom to read stderr data.

ReceiveBytes Method (SSHClient Component)

Reads a portion of received data into a byte array.

Syntax

• C#
• VB.NET

public byte[] ReceiveBytes(int maxLen);

Public Function ReceiveBytes(ByVal MaxLen As Integer) As Byte()

Remarks

Use this method to read out a piece of data received from the server into a byte array. Control the maximum length of the data chunk with the MaxLen parameter.

Note that in synchronous mode this method may block in the absence of any inbound data until the next piece of data is received from the server. Use Poll to check if there is any data in the connection that is immediately available for reading.

In asynchronous mode a good time to call this method is upon receiving a read notification in DataReceived event handler. When working in asynchronous mode, this call returns immediately.

This method only returns data that arrives via the stdout channel. Use ReceiveBytesFrom to read stderr data.

ReceiveBytesFrom Method (SSHClient Component)

Reads a portion of data received via a specific channel into a byte array.

Syntax

• C#
• VB.NET

public byte[] ReceiveBytesFrom(int channel, int maxLen);

Public Function ReceiveBytesFrom(ByVal Channel As Integer, ByVal MaxLen As Integer) As Byte()

Remarks

Use this method to read out a piece of data received from the server into a byte array. Specify the channel that you are interested in reading from (0 for stdout, 1 for stderr) via the Channel parameter, and control the maximum length of the data chunk with the MaxLen parameter.

Note that in synchronous mode this method may block in the absence of any inbound data until the next piece of data is received from the server. Use Poll to check if there is any data in the connection that is immediately available for reading.

In asynchronous mode a good time to call this method is upon receiving a read notification in DataReceived event handler. When working in asynchronous mode, this call returns immediately.

Please also note that stdout and stderr channels are fully independent, which implies that data arriving via each channel should be read out separately.

ReceiveFrom Method (SSHClient Component)

Reads a portion of data received via a specific channel into a string.

Syntax

• C#
• VB.NET

public string ReceiveFrom(int channel);

Public Function ReceiveFrom(ByVal Channel As Integer) As String

Remarks

Use this method to read out a piece of data received from the server into a string. Use the Channel parameter to specify the channel that you would like to read from (0 for stdout, 1 for stderr).

Note that in synchronous mode this method may block in the absence of any inbound data until the next piece of data is received from the server. Use Poll to check if there is any data in the connection that is immediately available for reading.

In asynchronous mode a good time to call this method is upon receiving a read notification in DataReceived event handler. When working in asynchronous mode, this call returns immediately.

Reset Method (SSHClient Component)

Resets the component settings.

Syntax

• C#
• VB.NET

public void Reset();

Public Sub Reset()

Remarks

Reset is a generic method available in every component.

Send Method (SSHClient Component)

Sends a string to the server.

Syntax

• C#
• VB.NET

public void Send(string dataStr, bool addEOL);

Public Sub Send(ByVal DataStr As String, ByVal AddEOL As Boolean)

Remarks

Use this method to send DataStr to the remote command's stdin channel. Set the AddEOL parameter to true to append the end-of-line character to the string automatically.

Note that in synchronous mode this method may block until the whole string is commited to the network connection. In asynchronous mode this method returns immediately; the application is eventually notified that the data has been sent via the DataSent event.

SendBytes Method (SSHClient Component)

Sends an array of bytes to the server.

Syntax

• C#
• VB.NET

public void SendBytes(byte[] data);

Public Sub SendBytes(ByVal Data As Byte())

Remarks

Use this method to send Data to the remote command's stdin channel.

Note that in synchronous mode this method may block until the whole byte array is commited to the network connection. In asynchronous mode this method returns immediately; the application is eventually notified that the data has been sent via the DataSent event.

SendSpecial Method (SSHClient Component)

Sends a special character to the server or remote command.

Syntax

• C#
• VB.NET

public void SendSpecial(string specialChar);

Public Sub SendSpecial(ByVal SpecialChar As String)

Remarks

Use this method to send a special or control character to the SSH server or the command being executed. Specify the character id via the SpecialChar parameter.

Currently the only supported special character is "eof", which is sometimes used as a way to close the stdin channel gracefully.

AuthAttempt Event (SSHClient Component)

Fires when a single authentication attempt is performed.

Syntax

• C#
• VB.NET

public event OnAuthAttemptHandler OnAuthAttempt;

public delegate void OnAuthAttemptHandler(object sender, SSHClientAuthAttemptEventArgs e);

public class SSHClientAuthAttemptEventArgs : EventArgs {
  public int AuthType { get; }
}

Public Event OnAuthAttempt As OnAuthAttemptHandler

Public Delegate Sub OnAuthAttemptHandler(sender As Object, e As SSHClientAuthAttemptEventArgs)

Public Class SSHClientAuthAttemptEventArgs Inherits EventArgs
  Public ReadOnly Property AuthType As Integer
End Class

Remarks

This event is fired each time a single authentication attempt is performed. AuthType parameter specifies the type of authentication. Note, this event could be fired more than once if the client tries different authentication methods one after another.

AuthFailed Event (SSHClient Component)

Fires when a single authentication attempt is failed.

Syntax

• C#
• VB.NET

public event OnAuthFailedHandler OnAuthFailed;

public delegate void OnAuthFailedHandler(object sender, SSHClientAuthFailedEventArgs e);

public class SSHClientAuthFailedEventArgs : EventArgs {
  public int AuthenticationType { get; }
}

Public Event OnAuthFailed As OnAuthFailedHandler

Public Delegate Sub OnAuthFailedHandler(sender As Object, e As SSHClientAuthFailedEventArgs)

Public Class SSHClientAuthFailedEventArgs Inherits EventArgs
  Public ReadOnly Property AuthenticationType As Integer
End Class

Remarks

This event is fired each time a single authentication attempt fails. AuthType parameter specifies the type of authentication.

As SSH may try a number of authentication attempts of different types or with different parameters (such as public keys) during one session, this event may be fired more than once. It is not critical and may not lead to closing of the connection.

AuthSucceeded Event (SSHClient Component)

Reports a successful authentication.

Syntax

• C#
• VB.NET

public event OnAuthSucceededHandler OnAuthSucceeded;

public delegate void OnAuthSucceededHandler(object sender, SSHClientAuthSucceededEventArgs e);

public class SSHClientAuthSucceededEventArgs : EventArgs {
}

Public Event OnAuthSucceeded As OnAuthSucceededHandler

Public Delegate Sub OnAuthSucceededHandler(sender As Object, e As SSHClientAuthSucceededEventArgs)

Public Class SSHClientAuthSucceededEventArgs Inherits EventArgs
End Class

Remarks

This event may be preceded by some AuthFailed events if the client tries different authentication methods one after another.

Banner Event (SSHClient Component)

Reports the receipt of the Hello message from the server.

Syntax

• C#
• VB.NET

public event OnBannerHandler OnBanner;

public delegate void OnBannerHandler(object sender, SSHClientBannerEventArgs e);

public class SSHClientBannerEventArgs : EventArgs {
  public byte[] Text { get; }
  public byte[] Language { get; }
}

Public Event OnBanner As OnBannerHandler

Public Delegate Sub OnBannerHandler(sender As Object, e As SSHClientBannerEventArgs)

Public Class SSHClientBannerEventArgs Inherits EventArgs
  Public ReadOnly Property Text As Byte()
  Public ReadOnly Property Language As Byte()
End Class

Remarks

SFPTClient fires this event when it receives hello message from the server.

CommandCompleted Event (SSHClient Component)

Signifies completion of the command execution.

Syntax

• C#
• VB.NET

public event OnCommandCompletedHandler OnCommandCompleted;

public delegate void OnCommandCompletedHandler(object sender, SSHClientCommandCompletedEventArgs e);

public class SSHClientCommandCompletedEventArgs : EventArgs {
  public string Command { get; }
  public int ExitStatus { get; }
  public string ExitMessage { get; }
  public string ExitSignal { get; }
}

Public Event OnCommandCompleted As OnCommandCompletedHandler

Public Delegate Sub OnCommandCompletedHandler(sender As Object, e As SSHClientCommandCompletedEventArgs)

Public Class SSHClientCommandCompletedEventArgs Inherits EventArgs
  Public ReadOnly Property Command As String
  Public ReadOnly Property ExitStatus As Integer
  Public ReadOnly Property ExitMessage As String
  Public ReadOnly Property ExitSignal As String
End Class

Remarks

Subscribe to this event to be notified about completion of the remote command execution. This event fires for every command in the Commands list. The Command parameter indicates the command being completed.

ExitStatus specifies the command's return code. ExitMessage or ExitSignal parameters provide error details if the command execution was terminated forcefully,

CommandStart Event (SSHClient Component)

Marks the commencement of a command execution.

Syntax

• C#
• VB.NET

public event OnCommandStartHandler OnCommandStart;

public delegate void OnCommandStartHandler(object sender, SSHClientCommandStartEventArgs e);

public class SSHClientCommandStartEventArgs : EventArgs {
  public string Command { get; }
}

Public Event OnCommandStart As OnCommandStartHandler

Public Delegate Sub OnCommandStartHandler(sender As Object, e As SSHClientCommandStartEventArgs)

Public Class SSHClientCommandStartEventArgs Inherits EventArgs
  Public ReadOnly Property Command As String
End Class

Remarks

Subscribe to this event to be notified about the start of execution of a remote command. The Command parameter indicates the command being started.

This event is fired for all commands in the Commands list, in order. The completion of the command is reported via the CommandCompleted event.

Connect Event (SSHClient Component)

This event is fired when an SSH session has been established.

Syntax

• C#
• VB.NET

public event OnConnectHandler OnConnect;

public delegate void OnConnectHandler(object sender, SSHClientConnectEventArgs e);

public class SSHClientConnectEventArgs : EventArgs {
}

Public Event OnConnect As OnConnectHandler

Public Delegate Sub OnConnectHandler(sender As Object, e As SSHClientConnectEventArgs)

Public Class SSHClientConnectEventArgs Inherits EventArgs
End Class

Remarks

Use this event to track the moment when SSH session has been set up.

DataReceived Event (SSHClient Component)

Reports receipt of another chunk of data from the server.

Syntax

• C#
• VB.NET

public event OnDataReceivedHandler OnDataReceived;

public delegate void OnDataReceivedHandler(object sender, SSHClientDataReceivedEventArgs e);

public class SSHClientDataReceivedEventArgs : EventArgs {
  public int Channel { get; }
  public int BytesReceived { get; }
  public int TotalBytesPending { get; }
}

Public Event OnDataReceived As OnDataReceivedHandler

Public Delegate Sub OnDataReceivedHandler(sender As Object, e As SSHClientDataReceivedEventArgs)

Public Class SSHClientDataReceivedEventArgs Inherits EventArgs
  Public ReadOnly Property Channel As Integer
  Public ReadOnly Property BytesReceived As Integer
  Public ReadOnly Property TotalBytesPending As Integer
End Class

Remarks

This event fires in asynchronous mode to report the receipt of another chunk of data from the server. Use Receive or ReceiveBytes methods to read out the received data.

The Channel parameter indicates the channel on which the data was received: stdout (0) or stderr (1). BytesReceived specify the size of the newly received chunk, and TotalBytesPending contain the total number of bytes available for reading.

Please note that just like other asynchronous mode events this event may fire from a secondary thread. Please make sure your code is prepared for that by using appropriate synchronization facilities.

This event does not fire in synchronous mode.

DataSent Event (SSHClient Component)

Notifies the application that a piece of data has been sent to the server.

Syntax

• C#
• VB.NET

public event OnDataSentHandler OnDataSent;

public delegate void OnDataSentHandler(object sender, SSHClientDataSentEventArgs e);

public class SSHClientDataSentEventArgs : EventArgs {
  public int BytesSent { get; }
  public int BytesPending { get; }
}

Public Event OnDataSent As OnDataSentHandler

Public Delegate Sub OnDataSentHandler(sender As Object, e As SSHClientDataSentEventArgs)

Public Class SSHClientDataSentEventArgs Inherits EventArgs
  Public ReadOnly Property BytesSent As Integer
  Public ReadOnly Property BytesPending As Integer
End Class

Remarks

Subscribe to this event to be notified about the outbound data flow. This event fires following a call to Send or SendBytes methods to notify the application that the data provided has been sent to the server. This event may fire more than once for each Send or SendBytes call, subject to the volume of data being sent and the settings of the server.

The BytesSent parameter specifies the number of bytes that has just been sent to the server. The BytesPending indicate the number of bytes that remain cached in the internal buffer. Any bytes cached in such way will be sent again on the next available opportunity and reported via a separate DataSent event invocation.

Please note that just like other asynchronous mode events this event may fire from a secondary thread. Please make sure your code is prepared for that by using appropriate synchronization facilities.

This event does not fire in synchronous mode.

Disconnect Event (SSHClient Component)

This event is fired when the SFTP subsystem connection is closed.

Syntax

• C#
• VB.NET

public event OnDisconnectHandler OnDisconnect;

public delegate void OnDisconnectHandler(object sender, SSHClientDisconnectEventArgs e);

public class SSHClientDisconnectEventArgs : EventArgs {
  public int CloseReason { get; }
}

Public Event OnDisconnect As OnDisconnectHandler

Public Delegate Sub OnDisconnectHandler(sender As Object, e As SSHClientDisconnectEventArgs)

Public Class SSHClientDisconnectEventArgs Inherits EventArgs
  Public ReadOnly Property CloseReason As Integer
End Class

Remarks

Do not perform any file operations after this event has been fired.

Error Event (SSHClient Component)

Information about errors during SFTP connection.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

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

public class SSHClientErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

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

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

Remarks

The event is fired in case of exceptional conditions during data transfer.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of error codes please refer to SFTP.

ExternalSign Event (SSHClient Component)

Handles remote or external signing initiated by the SignExternal method or other source.

Syntax

• C#
• VB.NET

public event OnExternalSignHandler OnExternalSign;

public delegate void OnExternalSignHandler(object sender, SSHClientExternalSignEventArgs e);

public class SSHClientExternalSignEventArgs : EventArgs {
  public string OperationId { get; }
  public string HashAlgorithm { get; }
  public string Pars { get; }
  public string Data { get; }
  public string SignedData { get; set; }
}

Public Event OnExternalSign As OnExternalSignHandler

Public Delegate Sub OnExternalSignHandler(sender As Object, e As SSHClientExternalSignEventArgs)

Public Class SSHClientExternalSignEventArgs Inherits EventArgs
  Public ReadOnly Property OperationId As String
  Public ReadOnly Property HashAlgorithm As String
  Public ReadOnly Property Pars As String
  Public ReadOnly Property Data As String
  Public Property SignedData As String
End Class

Remarks

Assign a handler to this event if you need to delegate a low-level signing operation to an external, remote, or custom signing engine. Depending on the settings, the handler will receive a hashed or unhashed value to be signed.

The event handler must pass the value of Data to the signer, obtain the signature, and pass it back to the component via the SignedData parameter.

OperationId provides a comment about the operation and its origin. It depends on the exact component being used, and may be empty. HashAlgorithm specifies the hash algorithm being used for the operation, and Pars contains algorithm-dependent parameters.

The component uses base16 (hex) encoding for the Data, SignedData, and Pars parameters. If your signing engine uses a different input and output encoding, you may need to decode and/or encode the data before and/or after the signing.

A sample MD5 hash encoded in base16: a0dee2a0382afbb09120ffa7ccd8a152 - lower case base16 A0DEE2A0382AFBB09120FFA7CCD8A152 - upper case base16

A sample event handler that uses the .NET RSACryptoServiceProvider class may look like the following: signer.OnExternalSign += (s, e) => { var cert = new X509Certificate2("cert.pfx", "", X509KeyStorageFlags.Exportable); var key = (RSACryptoServiceProvider)cert.PrivateKey; var dataToSign = e.Data.FromBase16String(); var signedData = key.SignHash(dataToSign, "2.16.840.1.101.3.4.2.1"); e.SignedData = signedData.ToBase16String(); };

KnownKeyReceived Event (SSHClient Component)

Signals that the server has introduced itself with a known key.

Syntax

• C#
• VB.NET

public event OnKnownKeyReceivedHandler OnKnownKeyReceived;

public delegate void OnKnownKeyReceivedHandler(object sender, SSHClientKnownKeyReceivedEventArgs e);

public class SSHClientKnownKeyReceivedEventArgs : EventArgs {
  public string Algorithm { get; }
  public int Bits { get; }
  public string FingerprintSHA256 { get; }
}

Public Event OnKnownKeyReceived As OnKnownKeyReceivedHandler

Public Delegate Sub OnKnownKeyReceivedHandler(sender As Object, e As SSHClientKnownKeyReceivedEventArgs)

Public Class SSHClientKnownKeyReceivedEventArgs Inherits EventArgs
  Public ReadOnly Property Algorithm As String
  Public ReadOnly Property Bits As Integer
  Public ReadOnly Property FingerprintSHA256 As String
End Class

Remarks

The component fires this event to tell the application that the server has introduced itself with a known key from TrustedKeysFile.

The details of the key are provided: Algorithm and Bits specify the key algorithm and the number of bits. FingerprintSHA256 contains the key's fingerprint.

Use ServerKey to access more key details.

Notification Event (SSHClient Component)

This event notifies the application about an underlying control flow event.

Syntax

• C#
• VB.NET

public event OnNotificationHandler OnNotification;

public delegate void OnNotificationHandler(object sender, SSHClientNotificationEventArgs e);

public class SSHClientNotificationEventArgs : EventArgs {
  public string EventID { get; }
  public string EventParam { get; }
}

Public Event OnNotification As OnNotificationHandler

Public Delegate Sub OnNotificationHandler(sender As Object, e As SSHClientNotificationEventArgs)

Public Class SSHClientNotificationEventArgs Inherits EventArgs
  Public ReadOnly Property EventID As String
  Public ReadOnly Property EventParam As String
End Class

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the component, the exact action it is performing, or the document being processed, one or both may be omitted.

PasswordChangeRequest Event (SSHClient Component)

This event is fired when a password change is requested.

Syntax

• C#
• VB.NET

public event OnPasswordChangeRequestHandler OnPasswordChangeRequest;

public delegate void OnPasswordChangeRequestHandler(object sender, SSHClientPasswordChangeRequestEventArgs e);

public class SSHClientPasswordChangeRequestEventArgs : EventArgs {
  public string Prompt { get; }
  public string NewPassword { get; set; }
  public bool Cancel { get; set; }
}

Public Event OnPasswordChangeRequest As OnPasswordChangeRequestHandler

Public Delegate Sub OnPasswordChangeRequestHandler(sender As Object, e As SSHClientPasswordChangeRequestEventArgs)

Public Class SSHClientPasswordChangeRequestEventArgs Inherits EventArgs
  Public ReadOnly Property Prompt As String
  Public Property NewPassword As String
  Public Property Cancel As Boolean
End Class

Remarks

This event is fired by the component when a password change is requested by the server. Prompt contains the password prompt message. Handler should either provide the new password via NewPassword, or deny the request by setting Cancel to true.

PrivateKeyNeeded Event (SSHClient Component)

This event is fired when client's public key was accepted by the server, but the corresponding secret key is not available.

Syntax

• C#
• VB.NET

public event OnPrivateKeyNeededHandler OnPrivateKeyNeeded;

public delegate void OnPrivateKeyNeededHandler(object sender, SSHClientPrivateKeyNeededEventArgs e);

public class SSHClientPrivateKeyNeededEventArgs : EventArgs {
  public bool Skip { get; set; }
}

Public Event OnPrivateKeyNeeded As OnPrivateKeyNeededHandler

Public Delegate Sub OnPrivateKeyNeededHandler(sender As Object, e As SSHClientPrivateKeyNeededEventArgs)

Public Class SSHClientPrivateKeyNeededEventArgs Inherits EventArgs
  Public Property Skip As Boolean
End Class

Remarks

Set Skip to true when it is not possible to load the missing key for some reason.

UnknownKeyReceived Event (SSHClient Component)

Signals that the server has introduced itself with an unknown key.

Syntax

• C#
• VB.NET

public event OnUnknownKeyReceivedHandler OnUnknownKeyReceived;

public delegate void OnUnknownKeyReceivedHandler(object sender, SSHClientUnknownKeyReceivedEventArgs e);

public class SSHClientUnknownKeyReceivedEventArgs : EventArgs {
  public string Algorithm { get; }
  public int Bits { get; }
  public string FingerprintSHA256 { get; }
  public int Action { get; set; }
}

Public Event OnUnknownKeyReceived As OnUnknownKeyReceivedHandler

Public Delegate Sub OnUnknownKeyReceivedHandler(sender As Object, e As SSHClientUnknownKeyReceivedEventArgs)

Public Class SSHClientUnknownKeyReceivedEventArgs Inherits EventArgs
  Public ReadOnly Property Algorithm As String
  Public ReadOnly Property Bits As Integer
  Public ReadOnly Property FingerprintSHA256 As String
  Public Property Action As Integer
End Class

Remarks

The component fires this event to tell the application that the server has introduced itself with a key not present in TrustedKeysFile.

The details of the key are provided: Algorithm and Bits specify the key algorithm and the number of bits. FingerprintSHA256 contains the key's fingerprint.

In this event handler, you need to make a decision whether to proceed with the connection. Use Action to tell the component what it should do with the key:

ExternalCrypto Type

Specifies the parameters of external cryptographic calls.

Remarks

External cryptocalls are used in a Distributed Cryptography (DC) subsystem, which allows the delegation of security operations to the remote agent. For instance, it can be used to compute the signature value on the server, while retaining the client's private key locally.

Fields

Constructors

• C#
• VB.NET

public ExternalCrypto();

Public ExternalCrypto()

ProxySettings Type

A container for proxy server settings.

Remarks

This type exposes a collection of properties for tuning up the proxy server configuration.

Fields

Constructors

• C#
• VB.NET

public ProxySettings();

Public ProxySettings()

SocketSettings Type

A container for the socket settings.

Remarks

This type is a container for socket-layer parameters.

Fields

Constructors

• C#
• VB.NET

public SocketSettings();

Public SocketSettings()

SSHConnectionInfo Type

Contains information about SSH connection.

Remarks

SSHConnectionInfo object contains information about one SSH connection.

Fields

Constructors

• C#
• VB.NET

public SSHConnectionInfo();

Public SSHConnectionInfo()

SSHKey Type

SSHKey is used to store information about single compound public-key algorithm (such as RSA or DSA) key.

Remarks

SSH keys are used to secure the SSH protocol flow. They support different algorithms and key lengths, a very typical example being RSA-2048 bits.

Fields

Constructors

• C#
• VB.NET

public SSHKey(byte[] bytes, int startIndex, int count, string password);

Public SSHKey(ByVal Bytes As Byte(), ByVal StartIndex As Integer, ByVal Count As Integer, ByVal Password As String)

• C#
• VB.NET

public SSHKey(byte[] bytes, int startIndex, int count);

Public SSHKey(ByVal Bytes As Byte(), ByVal StartIndex As Integer, ByVal Count As Integer)

• C#
• VB.NET

public SSHKey(System.IO.Stream stream, string password);

Public SSHKey(ByVal Stream As System.IO.Stream, ByVal Password As String)

• C#
• VB.NET

public SSHKey(System.IO.Stream stream);

Public SSHKey(ByVal Stream As System.IO.Stream)

• C#
• VB.NET

public SSHKey(string path, string password);

Public SSHKey(ByVal Path As String, ByVal Password As String)

• C#
• VB.NET

public SSHKey(string path);

Public SSHKey(ByVal Path As String)

• C#
• VB.NET

public SSHKey();

Public SSHKey()

SSHSettings Type

A container for various SSH protocol settings.

Remarks

SSHSettings stores various settings of SSH client or server.

Fields

Constructors

• C#
• VB.NET

public SSHSettings();

Public SSHSettings()

SSHTerm Type

A container for SSH terminal settings.

Remarks

SSHTerm stores terminal settings of the SSH client.

Fields

Config Settings (SSHClient Component)

SSHClient Config Settings

Base Config Settings

Trappable Errors (SSHClient Component)