SSHClient Component

Properties   Methods   Events   Config Settings   Errors  

The SSHClient component provides client-side SSH protocol functionality.

Syntax

TsbxSSHClient

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

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

Method List

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

Event List

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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

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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

property AsyncMode: Boolean read get_AsyncMode write set_AsyncMode;

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

property AuthAttempts: Integer read get_AuthAttempts write set_AuthAttempts;

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

property Commands: String read get_Commands write set_Commands;

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

property Connected: Boolean read get_Connected;

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

property ConnectionInfo: TsbxSSHConnectionInfo read get_ConnectionInfo;

Remarks

This property contains various information about the secure connection.

This property is read-only.

Please refer to the SSHConnectionInfo type for a complete list of fields.

ExitMessage Property (SSHClient Component)

Contains the last commands exit message.

Syntax

property ExitMessage: String read get_ExitMessage;

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

property ExitSignal: String read get_ExitSignal;

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

property ExitStatus: Integer read get_ExitStatus;

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

property ExternalCrypto: TsbxExternalCrypto read get_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.

Please refer to the ExternalCrypto type for a complete list of fields.

FIPSMode Property (SSHClient Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

Key Property (SSHClient Component)

Contains client's SSH key.

Syntax

property Key: TsbxSSHKey read get_Key write set_Key;

Remarks

Server's public key is returned by ServerKey property.

Please refer to the SSHKey type for a complete list of fields.

Password Property (SSHClient Component)

Specifies user's password on the server.

Syntax

property Password: String read get_Password write set_Password;

Default Value

''

Remarks

Invalid password fires the AuthFailed event.

Proxy Property (SSHClient Component)

Allows connection through a proxy server.

Syntax

property Proxy: TsbxProxySettings read get_Proxy;

Remarks

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

This property is read-only.

Please refer to the ProxySettings type for a complete list of fields.

ServerKey Property (SSHClient Component)

Returns server's public key.

Syntax

property ServerKey: TsbxSSHKey read get_ServerKey;

Remarks

Client's SSH key is specified by Key.

This property is read-only.

Please refer to the SSHKey type for a complete list of fields.

SocketSettings Property (SSHClient Component)

Manages network connection settings.

Syntax

property SocketSettings: TsbxSocketSettings read get_SocketSettings;

Remarks

Use this property to tune up network connection parameters.

This property is read-only.

Please refer to the SocketSettings type for a complete list of fields.

SSHSettings Property (SSHClient Component)

Provides access to SSH connection settings.

Syntax

property SSHSettings: TsbxSSHSettings read get_SSHSettings;

Remarks

Use this property to configure SSH protocol settings.

This property is read-only.

Please refer to the SSHSettings type for a complete list of fields.

Subsystem Property (SSHClient Component)

Specifies the subsystem to request from the server.

Syntax

property Subsystem: String read get_Subsystem write set_Subsystem;

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

property Terminal: TsbxSSHTerm read get_Terminal;

Remarks

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

This property is read-only.

Please refer to the SSHTerm type for a complete list of fields.

TrustedKeysFile Property (SSHClient Component)

Path to the file containing public keys of authorized servers.

Syntax

property TrustedKeysFile: String read get_TrustedKeysFile write set_TrustedKeysFile;

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

property Username: String read get_Username write set_Username;

Default Value

''

Remarks

Client's password is set by Password property. ;

Config Method (SSHClient Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): 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

procedure Connect(Address: String; Port: 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

function ConnectAndExec(Address: String; Port: Integer; Command: String; WantStdout: Boolean; WantStdErr: Boolean): TBytes;

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

procedure 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

function DoAction(ActionID: String; ActionParams: String): 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

procedure 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

function Poll(Milliseconds: Integer): 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

function Receive(): 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

function ReceiveBytes(MaxLen: Integer): TBytes;

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

function ReceiveBytesFrom(Channel: Integer; MaxLen: Integer): TBytes;

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

function ReceiveFrom(Channel: Integer): 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

procedure Reset();

Remarks

Reset is a generic method available in every component.

Send Method (SSHClient Component)

Sends a string to the server.

Syntax

procedure Send(DataStr: String; AddEOL: 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

procedure SendBytes(Data: TBytes);

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

procedure SendSpecial(SpecialChar: 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

type TAuthAttemptEvent = procedure (
  Sender: TObject;
  AuthType: Integer
) of Object;

property OnAuthAttempt: TAuthAttemptEvent read FOnAuthAttempt write FOnAuthAttempt;

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

type TAuthFailedEvent = procedure (
  Sender: TObject;
  AuthenticationType: Integer
) of Object;

property OnAuthFailed: TAuthFailedEvent read FOnAuthFailed write FOnAuthFailed;

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

type TAuthSucceededEvent = procedure (
  Sender: TObject
) of Object;

property OnAuthSucceeded: TAuthSucceededEvent read FOnAuthSucceeded write FOnAuthSucceeded;

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

type TBannerEvent = procedure (
  Sender: TObject;
  const Text: TBytes;
  const Language: TBytes
) of Object;

property OnBanner: TBannerEvent read FOnBanner write FOnBanner;

Remarks

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

CommandCompleted Event (SSHClient Component)

Signifies completion of the command execution.

Syntax

type TCommandCompletedEvent = procedure (
  Sender: TObject;
  const Command: String;
  ExitStatus: Integer;
  const ExitMessage: String;
  const ExitSignal: String
) of Object;

property OnCommandCompleted: TCommandCompletedEvent read FOnCommandCompleted write FOnCommandCompleted;

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

type TCommandStartEvent = procedure (
  Sender: TObject;
  const Command: String
) of Object;

property OnCommandStart: TCommandStartEvent read FOnCommandStart write FOnCommandStart;

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

type TConnectEvent = procedure (
  Sender: TObject
) of Object;

property OnConnect: TConnectEvent read FOnConnect write FOnConnect;

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

type TDataReceivedEvent = procedure (
  Sender: TObject;
  Channel: Integer;
  BytesReceived: Integer;
  TotalBytesPending: Integer
) of Object;

property OnDataReceived: TDataReceivedEvent read FOnDataReceived write FOnDataReceived;

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

type TDataSentEvent = procedure (
  Sender: TObject;
  BytesSent: Integer;
  BytesPending: Integer
) of Object;

property OnDataSent: TDataSentEvent read FOnDataSent write FOnDataSent;

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

type TDisconnectEvent = procedure (
  Sender: TObject;
  CloseReason: Integer
) of Object;

property OnDisconnect: TDisconnectEvent read FOnDisconnect write FOnDisconnect;

Remarks

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

Error Event (SSHClient Component)

Information about errors during SFTP connection.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

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

type TExternalSignEvent = procedure (
  Sender: TObject;
  const OperationId: String;
  const HashAlgorithm: String;
  const Pars: String;
  const Data: String;
  var SignedData: String
) of Object;

property OnExternalSign: TExternalSignEvent read FOnExternalSign write FOnExternalSign;

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

type TKnownKeyReceivedEvent = procedure (
  Sender: TObject;
  const Algorithm: String;
  Bits: Integer;
  const FingerprintSHA256: String
) of Object;

property OnKnownKeyReceived: TKnownKeyReceivedEvent read FOnKnownKeyReceived write FOnKnownKeyReceived;

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

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

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

type TPasswordChangeRequestEvent = procedure (
  Sender: TObject;
  const Prompt: String;
  var NewPassword: String;
  var Cancel: Boolean
) of Object;

property OnPasswordChangeRequest: TPasswordChangeRequestEvent read FOnPasswordChangeRequest write FOnPasswordChangeRequest;

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

type TPrivateKeyNeededEvent = procedure (
  Sender: TObject;
  var Skip: Boolean
) of Object;

property OnPrivateKeyNeeded: TPrivateKeyNeededEvent read FOnPrivateKeyNeeded write FOnPrivateKeyNeeded;

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

type TUnknownKeyReceivedEvent = procedure (
  Sender: TObject;
  const Algorithm: String;
  Bits: Integer;
  const FingerprintSHA256: String;
  var Action: Integer
) of Object;

property OnUnknownKeyReceived: TUnknownKeyReceivedEvent read FOnUnknownKeyReceived write FOnUnknownKeyReceived;

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:

Note that accepting an unknown and unchecked key may be risky.

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

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constructor Create();

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

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constructor Create();

SocketSettings Type

A container for the socket settings.

Remarks

This type is a container for socket-layer parameters.

Fields

Constructors

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constructor Create();

SSHConnectionInfo Type

Contains information about SSH connection.

Remarks

SSHConnectionInfo object contains information about one SSH connection.

Fields

Constructors

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constructor Create();

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

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constructor Create();

SSHSettings Type

A container for various SSH protocol settings.

Remarks

SSHSettings stores various settings of SSH client or server.

Fields

Constructors

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constructor Create();

SSHTerm Type

A container for SSH terminal settings.

Remarks

SSHTerm stores terminal settings of the SSH client.

Fields

Config Settings (SSHClient 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.

SSHClient Config Settings

Base Config Settings

Trappable Errors (SSHClient Component)