SSHServer Control
Properties Methods Events Config Settings Errors
The SSHServer control is used to create Secure Shell (SSH) servers. The control handles multiple simultaneous connections on the same TCP/IP port (service port). It is designed to balance the load between connections for a fast, powerful server.
Syntax
SSHServer
Remarks
The SSHServer control is the SSH-enabled equivalent of the IPWorks TCPServer control, extended by a set of new properties and events that deal with SSH security. The SSHCompressionAlgorithms and SSHEncryptionAlgorithms properties determine which protocols are enabled for the SSH handshake. The SSHCert* properties are used to select a certificate for the server (please note that a valid certificate MUST be selected before the server can function). The SSHUserAuthRequest event will allow you to use authenticate clients using digital certificates or passwords. Finally, the SSHStatus event provides information about the SSH handshake and underlying protocol notifications.
By default, each instance of SSHServer can handle up to 1000 simultaneous incoming connections (this number may be increased up to 100,000, or decreased to a lower value by using the MaxConnections configuration setting).
SSH connections are identified by a ConnectionId. Events relating to these connections as a whole will use the ConnectionId to identify the specific connection. Connections may also contained one or more multiplexed channels, which are identified by a ChannelId. Channel-level events will specify the ChannelId to which they relate.
SSHServer can start to listen on a port by setting the Listening property to True. When a remote host asks for a connection, the ConnectionRequest event is fired. At that point, the connection can either be accepted or rejected. If the connection is accepted, a ConnectionId is assigned, and communication can start. From this point on, the operation is very similar to SSHClient. Data can be sent to an individual SSHChannel using SendChannelData. The address and port of the incoming connection can be found by querying the ClientRemoteHost and ClientRemotePort properties.
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 control with short descriptions. Click on the links for further details.
SSHChannelCount | The number of records in the arrays. |
BytesSent | The number of bytes actually sent after a sending channel data. |
ChannelId | An id generated by the control to identify the current SSH channel. |
DataToSend | A string of data to be sent to the remote host. |
ReadyToSend | This property is True when data can be sent over the SSH Channel. |
RecordLength | The length of received data records. |
Service | This property holds the channel type that was requested when opening the channel. |
ConnectionBacklog | This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem. |
SSHConnectionCount | The number of records in the SSHConnection arrays. |
SSHConnectionConnected | Used to disconnect individual connections and/or show their status. |
SSHConnectionLocalAddress | This property shows the IP address of the interface through which the connection is passing. |
SSHConnectionRemoteHost | The RemoteHost shows the IP address of the remote host through which the connection is coming. |
SSHConnectionRemotePort | The RemotePort shows the TCP port on the remote host through which the connection is coming. |
SSHConnectionTimeout | A timeout for the control. |
DefaultAuthMethods | Specifies the supported authentication methods. |
DefaultIdleTimeout | This property includes the default idle timeout for inactive clients. |
DefaultTimeout | An initial timeout value to be used by incoming connections. |
KeyboardInteractiveMessage | The instructions to send to the client during keyboard-interactive authentication. |
KeyboardInteractivePromptCount | The number of records in the KeyboardInteractivePrompt arrays. |
KeyboardInteractivePromptEcho | Specifies if the client should echo the value entered by the user or not. |
KeyboardInteractivePromptPrompt | The prompt label/text the client should present to the user. |
Listening | If set to True, the control accepts incoming connections on LocalPort. |
LocalHost | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
LocalPort | The TCP port in the local host where the control listens. |
SSHCertEncoded | This is the certificate (PEM/Base64 encoded). |
SSHCertStore | This is the name of the certificate store for the client certificate. |
SSHCertStorePassword | If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store. |
SSHCertStoreType | This is the type of certificate store for this certificate. |
SSHCertSubject | This is the subject of the certificate used for client authentication. |
SSHCompressionAlgorithms | A comma-separated list containing all allowable compression algorithms. |
SSHEncryptionAlgorithms | A comma-separated list containing all allowable encryption algorithms. |
Method List
The following is the full list of the methods of the control with short descriptions. Click on the links for further details.
ChangeRecordLength | Changes the length of received data records. |
CloseChannel | Closes a existing SSHChannel . |
Config | Sets or retrieves a configuration setting. |
Disconnect | This method disconnects the specified client. |
DoEvents | Processes events from the internal message queue. |
ExchangeKeys | Causes the control to exchange a new set of session keys on the specified connection. |
GetSSHParam | Used to read a field from an SSH packet's payload. |
GetSSHParamBytes | Used to read a field from an SSH packet's payload. |
OpenChannel | Opens a new SSHChannel . |
Reset | Reset the control. |
SendBytes | Sends binary data to the specified channel. |
SendChannelData | Used to send data over an SSH channel. |
SendSSHPacket | Used to send an encoded SSH packet to the server. |
SendText | Sends text to the specified channel. |
SetSSHParam | Used to write a field to the end of a payload. |
Shutdown | This method shuts down the server. |
StartListening | This method starts listening for incoming connections. |
StopListening | This method stops listening for new connections. |
Event List
The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.
Connected | This event is fired immediately after a connection completes (or fails). |
ConnectionRequest | This event is fired when a request for connection comes from a remote host. |
Disconnected | This event is fired when a connection is closed. |
Error | Information about errors during data delivery. |
Log | Fires once for each log message. |
SSHChannelClosed | Fired when a channel is closed. |
SSHChannelDataIn | Fired when data is received on an SSH channel. |
SSHChannelEOF | Fired when the remote peer signals the end of the data stream for the channel. |
SSHChannelOpened | Fired when a channel is successfully opened. |
SSHChannelOpenRequest | Fired when a client attempts to open a new channel. |
SSHChannelReadyToSend | Fired when the control is ready to send data. |
SSHChannelRequest | Fired when the SSHHost sends a channel request to the client. |
SSHChannelRequested | Fired if the SSHChannelRequest was successful, any further processing for the channel request should be done here. |
SSHServiceRequest | Fired when a client requests a service to be started. |
SSHStatus | Shows the progress of the secure connection. |
SSHTunnelClosed | This event will fire when a connected client attempts to close a tunnel. |
SSHTunnelRequested | This event fires when a connected client attempts to establish a forward or reverse tunnel. |
SSHUserAuthRequest | Fires when a client attempts to authenticate a connection. |
Config Settings
The following is a list of config settings for the control with short descriptions. Click on the links for further details.
AltSSHCertCount | The 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. |
ClientSSHVersionString[ConnectionId] | The client's version string. |
FireAuthRequestAfterSig | Whether to fire an informational event after the public key signature has been verified. |
KeyboardInteractivePrompts[ConnectionId] | Specifies custom keyboard-interactive prompts for particular connections. |
KeyRenegotiationThreshold | Sets the threshold for the SSH Key Renegotiation. |
LogLevel | Specifies the level of detail that is logged. |
MaxAuthAttempts | The maximum authentication attempts allowed before forcing a disconnect. |
NegotiatedStrictKex[ConnectionId] | Returns whether strict key exchange was negotiated to be used. |
ServerSSHVersionString | The SSH version string sent to connecting clients. |
SSHKeepAliveCountMax | The maximum number of keep alive packets to send without a response. |
SSHKeepAliveInterval | The interval between keep alive packets. |
SSHKeyExchangeAlgorithms | Specifies the supported key exchange algorithms. |
SSHMacAlgorithms | Specifies the supported Mac algorithms. |
SSHPubKeyAuthSigAlgorithms | Specifies the allowed signature algorithms used by a client performing public key authentication. |
SSHPublicKeyAlgorithms | Specifies the supported public key algorithms for the server's public key. |
SSHVersionPattern | The pattern used to match the remote host's version string. |
UserAuthBanner[ConnectionId] | A custom user authentication banner. |
UseStrictKeyExchange | Specifies how strict key exchange is supported. |
AllowedClients | A comma-separated list of host names or IP addresses that can access the control. |
BindExclusively | Whether or not the control considers a local port reserved for exclusive use. |
BlockedClients | A comma-separated list of host names or IP addresses that cannot access the control. |
DefaultConnectionTimeout | The inactivity timeout applied to the SSL handshake. |
InBufferSize | The size in bytes of the incoming queue of the socket. |
KeepAliveInterval | The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received. |
KeepAliveTime | The inactivity time in milliseconds before a TCP keep-alive packet is sent. |
MaxConnections | The maximum number of connections available. |
OutBufferSize | The size in bytes of the outgoing queue of the socket. |
TcpNoDelay | Whether or not to delay when sending packets. |
UseIPv6 | Whether to use IPv6. |
CodePage | The system code page used for Unicode to Multibyte translations. |
MaskSensitive | Whether sensitive data is masked in log messages. |
UseInternalSecurityAPI | Whether or not to use the system security libraries or an internal implementation. |
SSHChannelCount Property (SSHServer Control)
The number of records in the arrays.
Syntax
sshservercontrol.SSHChannelCount
Default Value
0
Remarks
This property controls the size of the following arrays:
- BytesSent
- ChannelId
- DataToSend
- KeyboardInteractivePromptEcho
- KeyboardInteractivePromptPrompt
- ReadyToSend
- RecordLength
- Service
- SSHCertEncoded
- SSHCertStore
- SSHCertStorePassword
- SSHCertStoreType
- SSHCertSubject
- SSHConnectionConnected
- SSHConnectionLocalAddress
- SSHConnectionRemoteHost
- SSHConnectionRemotePort
- SSHConnectionTimeout
The array indices start at 0 and end at SSHChannelCount - 1.
This property is read-only and not available at design time.
Data Type
Integer
BytesSent Property (SSHServer Control)
The number of bytes actually sent after a sending channel data.
Syntax
sshservercontrol.BytesSent(SSHChannelId)
Default Value
0
Remarks
The number of bytes actually sent after a sending channel data.
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
This property is read-only and not available at design time.
Data Type
Integer
ChannelId Property (SSHServer Control)
An id generated by the control to identify the current SSH channel.
Syntax
sshservercontrol.ChannelId(SSHChannelId)
Default Value
""
Remarks
An id generated by the control to identify the current SSH channel. This id is unique to this channel.
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
This property is read-only and not available at design time.
Data Type
String
DataToSend Property (SSHServer Control)
A string of data to be sent to the remote host.
Syntax
sshservercontrol.DataToSend(SSHChannelId)[=string]
Default Value
""
Remarks
A string of data to be sent to the remote host. Write-only property.
Assigning a string to the DataToSend makes the control send the string to the remote host.
Note:It is recommended to use the SendText or SendBytes method instead of setting this property.
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
To read or write binary data to the property, a Variant (Byte Array) version is provided in .DataToSendB.
This property is write-only and not available at design time.
Data Type
Binary String
ReadyToSend Property (SSHServer Control)
This property is True when data can be sent over the SSH Channel.
Syntax
sshservercontrol.ReadyToSend(SSHChannelId)
Default Value
False
Remarks
This property is True when data can be sent over the SSH Channel.
When Timeout is set to 0 (asynchronous) sending data may result in an error if the channel or underlying socket cannot accept more data to send. Monitor SSHChannelReadyToSend or ReadyToSend to determine when data can be sent again.
When Timeout is set to a positive value the control will block when sending data until the data can be successfully sent and SSHChannelReadyToSend and ReadyToSend do not need to be monitored.
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
This property is read-only and not available at design time.
Data Type
Boolean
RecordLength Property (SSHServer Control)
The length of received data records.
Syntax
sshservercontrol.RecordLength(SSHChannelId)[=integer]
Default Value
0
Remarks
The length of received data records. If set to a positive value, this setting defines the length of data records to be received. The control will accumulate data until RecordLength is reached and only then fire the SSHChannelDataIn event with data of length RecordLength. This allows data to be received as records of known length. This value can be changed at any time, including within the SSHChannelDataIn event.
The default value is 0, meaning this setting is not used.
Note:It is recommended to use the ChangeRecordLength method instead of setting this property.
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
This property is not available at design time.
Data Type
Integer
Service Property (SSHServer Control)
This property holds the channel type that was requested when opening the channel.
Syntax
sshservercontrol.Service(SSHChannelId)
Default Value
""
Remarks
This property holds the channel type that was requested when opening the channel. For instance "session" or "forwarded-tcpip".
The SSHChannelId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHChannelCount property.
This property is read-only and not available at design time.
Data Type
String
ConnectionBacklog Property (SSHServer Control)
This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.
Syntax
sshservercontrol.ConnectionBacklog[=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.
Data Type
Integer
SSHConnectionCount Property (SSHServer Control)
The number of records in the SSHConnection arrays.
Syntax
sshservercontrol.SSHConnectionCount
Default Value
0
Remarks
This property controls the size of the following arrays:
- SSHConnectionConnected
- SSHConnectionLocalAddress
- SSHConnectionRemoteHost
- SSHConnectionRemotePort
- SSHConnectionTimeout
The array indices start at 0 and end at SSHConnectionCount - 1.
This property is read-only and not available at design time.
Data Type
Integer
SSHConnectionConnected Property (SSHServer Control)
Used to disconnect individual connections and/or show their status.
Syntax
sshservercontrol.SSHConnectionConnected(ConnectionId)[=boolean]
Default Value
False
Remarks
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.
The ConnectionId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHConnectionCount property.
This property is not available at design time.
Data Type
Boolean
SSHConnectionLocalAddress Property (SSHServer Control)
This property shows the IP address of the interface through which the connection is passing.
Syntax
sshservercontrol.SSHConnectionLocalAddress(ConnectionId)
Default Value
""
Remarks
This property 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.
The ConnectionId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHConnectionCount property.
This property is read-only and not available at design time.
Data Type
String
SSHConnectionRemoteHost Property (SSHServer Control)
The RemoteHost shows the IP address of the remote host through which the connection is coming.
Syntax
sshservercontrol.SSHConnectionRemoteHost(ConnectionId)
Default Value
""
Remarks
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 control 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.
The ConnectionId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHConnectionCount property.
This property is read-only and not available at design time.
Data Type
String
SSHConnectionRemotePort Property (SSHServer Control)
The RemotePort shows the TCP port on the remote host through which the connection is coming.
Syntax
sshservercontrol.SSHConnectionRemotePort(ConnectionId)
Default Value
0
Remarks
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.
The ConnectionId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHConnectionCount property.
This property is read-only and not available at design time.
Data Type
Integer
SSHConnectionTimeout Property (SSHServer Control)
A timeout for the control.
Syntax
sshservercontrol.SSHConnectionTimeout(ConnectionId)[=integer]
Default Value
0
Remarks
A timeout for the control.
If the Timeout property is set to 0, all operations return immediately, potentially failing with an 'WOULDBLOCK' error if data can't be sent or received immediately.
If Timeout is set to a positive value, the control will automatically retry each operation that would otherwise result in a 'WOULDBLOCK' error for a maximum of Timeout seconds.
The control 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 control fails with an error.
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 Timeout property is 0 (asynchronous operation).
The ConnectionId parameter specifies the index of the item in the array. The size of the array is controlled by the SSHConnectionCount property.
This property is not available at design time.
Data Type
Integer
DefaultAuthMethods Property (SSHServer Control)
Specifies the supported authentication methods.
Syntax
sshservercontrol.DefaultAuthMethods[=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 control.
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 control:
none | This 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. |
password | AuthParam will contain the user-supplied password. If the password is correct, set Accept to true. |
publickey | AuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept or PartialSuccess to . The control will then handle verifying the digital signature and will respond to the client accordingly. |
keyboard-interactive | SSHUserAuthRequest 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. |
Data Type
String
DefaultIdleTimeout Property (SSHServer Control)
This property includes the default idle timeout for inactive clients.
Syntax
sshservercontrol.DefaultIdleTimeout[=integer]
Default Value
0
Remarks
This property specifies the idle timeout (in seconds) for clients. When set to a positive value, the control will disconnect idle clients after the specified timeout.
This applies only to clients that have not sent or received data within DefaultIdleTimeout seconds.
If set to 0 (default), no idle timeout is applied.
Note: DoEvents must be called for the control to check existing connections.
Data Type
Integer
DefaultTimeout Property (SSHServer Control)
An initial timeout value to be used by incoming connections.
Syntax
sshservercontrol.DefaultTimeout[=integer]
Default Value
60
Remarks
This property is used by the control to set the operational timeout value of all inbound connections once they are established. If the timeout is set to 0, all inbound connections will behave asynchronously. The default value is 60, meaning the control will behave synchronously.
Data Type
Integer
KeyboardInteractiveMessage Property (SSHServer Control)
The instructions to send to the client during keyboard-interactive authentication.
Syntax
sshservercontrol.KeyboardInteractiveMessage[=string]
Default Value
""
Remarks
This property should be set to the main instructions to send to the client during keyboard-interactive authentication.
Data Type
String
KeyboardInteractivePromptCount Property (SSHServer Control)
The number of records in the KeyboardInteractivePrompt arrays.
Syntax
sshservercontrol.KeyboardInteractivePromptCount[=integer]
Default Value
0
Remarks
This property controls the size of the following arrays:
The array indices start at 0 and end at KeyboardInteractivePromptCount - 1.
This property is not available at design time.
Data Type
Integer
KeyboardInteractivePromptEcho Property (SSHServer Control)
Specifies if the client should echo the value entered by the user or not.
Syntax
sshservercontrol.KeyboardInteractivePromptEcho(PromptIndex)[=boolean]
Default Value
False
Remarks
Specifies if the client should echo the value entered by the user or not.
The PromptIndex parameter specifies the index of the item in the array. The size of the array is controlled by the KeyboardInteractivePromptCount property.
This property is not available at design time.
Data Type
Boolean
KeyboardInteractivePromptPrompt Property (SSHServer Control)
The prompt label/text the client should present to the user.
Syntax
sshservercontrol.KeyboardInteractivePromptPrompt(PromptIndex)[=string]
Default Value
""
Remarks
The prompt label/text the client should present to the user.
The PromptIndex parameter specifies the index of the item in the array. The size of the array is controlled by the KeyboardInteractivePromptCount property.
This property is not available at design time.
Data Type
String
Listening Property (SSHServer Control)
If set to True, the control accepts incoming connections on LocalPort.
Syntax
sshservercontrol.Listening[=boolean]
Default Value
False
Remarks
This property indicates whether the control is listening for connections on the port specified by the LocalPort property.
Note: Use the StartListening and StopListening methods to control whether the control is listening.
This property is not available at design time.
Data Type
Boolean
LocalHost Property (SSHServer Control)
The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
Syntax
sshservercontrol.LocalHost[=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 control initiate connections (or accept in the case of server controls) only through that interface.
If the control 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.
Data Type
String
LocalPort Property (SSHServer Control)
The TCP port in the local host where the control listens.
Syntax
sshservercontrol.LocalPort[=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).
Data Type
Integer
SSHCertEncoded Property (SSHServer Control)
This is the certificate (PEM/Base64 encoded).
Syntax
sshservercontrol.SSHCertEncoded[=string]
Default Value
""
Remarks
This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The Store and Subject properties 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.
To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSHCertEncodedB.
This property is not available at design time.
Data Type
Binary String
SSHCertStore Property (SSHServer Control)
This is the name of the certificate store for the client certificate.
Syntax
sshservercontrol.SSHCertStore[=string]
Default Value
"MY"
Remarks
This is the name of the certificate store for the client certificate.
The StoreType property 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 property 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 property for details.
Designations of certificate stores are platform dependent.
The following designations are the most common User and Machine certificate stores in Windows:
MY | A certificate store holding personal certificates with their associated private keys. |
CA | Certifying authority certificates. |
ROOT | Root 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., PKCS#12 certificate store).
To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSHCertStoreB.
Data Type
Binary String
SSHCertStorePassword Property (SSHServer Control)
If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
Syntax
sshservercontrol.SSHCertStorePassword[=string]
Default Value
""
Remarks
If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
Data Type
String
SSHCertStoreType Property (SSHServer Control)
This is the type of certificate store for this certificate.
Syntax
sshservercontrol.SSHCertStoreType[=integer]
Possible Values
cstUser(0), cstMachine(1), cstPFXFile(2), cstPFXBlob(3), cstJKSFile(4), cstJKSBlob(5), cstPEMKeyFile(6), cstPEMKeyBlob(7), cstPublicKeyFile(8), cstPublicKeyBlob(9), cstSSHPublicKeyBlob(10), cstP7BFile(11), cstP7BBlob(12), cstSSHPublicKeyFile(13), cstPPKFile(14), cstPPKBlob(15), cstXMLFile(16), cstXMLBlob(17), cstJWKFile(18), cstJWKBlob(19), cstSecurityKey(20), cstBCFKSFile(21), cstBCFKSBlob(22), cstPKCS11(23), cstAuto(99)
Default Value
0
Remarks
This is the type of certificate store for this certificate.
The control supports both public and private keys in a variety of formats. When the cstAuto value is used, the control will automatically determine the type. This property 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 (PKCS#12) file containing certificates. |
3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) 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 PKCS#7 file containing certificates. |
12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 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). |
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. |
23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface.
To use a security key, the necessary data must first be collected using the CertMgr control. The ListStoreCertificates method may be called after setting CertStoreType to cstPKCS11, CertStorePassword to the PIN, and CertStore to the full path of the PKCS#11 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:
|
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. |
Data Type
Integer
SSHCertSubject Property (SSHServer Control)
This is the subject of the certificate used for client authentication.
Syntax
sshservercontrol.SSHCertSubject[=string]
Default Value
""
Remarks
This is the subject of the certificate used for client authentication.
This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.
If a matching certificate is found, the property is set to the full subject of the matching certificate.
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 as follows:
Field | Meaning |
CN | Common Name. This is commonly a hostname like www.server.com. |
O | Organization |
OU | Organizational Unit |
L | Locality |
S | State |
C | Country |
E | Email Address |
If a field value contains a comma, it must be quoted.
Data Type
String
SSHCompressionAlgorithms Property (SSHServer Control)
A comma-separated list containing all allowable compression algorithms.
Syntax
sshservercontrol.SSHCompressionAlgorithms[=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 control 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 control:
- zlib
- zlib@openssh.com
- none
Data Type
String
SSHEncryptionAlgorithms Property (SSHServer Control)
A comma-separated list containing all allowable encryption algorithms.
Syntax
sshservercontrol.SSHEncryptionAlgorithms[=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 control 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 control:
aes256-ctr | 256-bit AES encryption in CTR mode |
aes256-cbc | 256-bit AES encryption in CBC mode |
aes192-ctr | 192-bit AES encryption in CTR mode |
aes192-cbc | 192-bit AES encryption in CBC mode |
aes128-ctr | 128-bit AES encryption in CTR mode |
aes128-cbc | 128-bit AES encryption in CBC mode |
3des-ctr | 192-bit (3-key) triple DES encryption in CTR mode |
3des-cbc | 192-bit (3-key) triple DES encryption in CBC mode |
cast128-cbc | CAST-128 encryption |
blowfish-cbc | Blowfish encryption |
arcfour | ARC4 encryption |
arcfour128 | 128-bit ARC4 encryption |
arcfour256 | 256-bit ARC4 encryption |
aes256-gcm@openssh.com | 256-bit AES encryption in GCM mode. |
aes128-gcm@openssh.com | 128-bit AES encryption in GCM mode. |
chacha20-poly1305@openssh.com | ChaCha20 with Poly1305-AES encryption. |
Data Type
String
ChangeRecordLength Method (SSHServer Control)
Changes the length of received data records.
Syntax
sshservercontrol.ChangeRecordLength ChannelId, RecordLength
Remarks
This method defines the length of data records to be received (in bytes) for the specified ChannelId.
If RecordLength is set to a positive value, the control will accumulate data until RecordLength bytes of data is received and only then fire the SSHChannelDataIn event with data of length RecordLength. This allows data to be received as records of known length. This method can be called at any time to change the record length, including within the DataIn event.
A value of 0 (default) means this functionality is not used.
CloseChannel Method (SSHServer Control)
Closes a existing SSHChannel .
Syntax
sshservercontrol.CloseChannel ChannelId
Remarks
ChannelId is the identifier for the SSH channel to be closed.
Config Method (SSHServer Control)
Sets or retrieves a configuration setting.
Syntax
sshservercontrol.Config ConfigurationString
Remarks
Config is a generic method available in every control. It is used to set and retrieve configuration settings for the control.
These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, 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 (SSHServer Control)
This method disconnects the specified client.
Syntax
sshservercontrol.Disconnect ConnectionId
Remarks
Calling this method will disconnect the client specified by the ConnectionId parameter.
DoEvents Method (SSHServer Control)
Processes events from the internal message queue.
Syntax
sshservercontrol.DoEvents
Remarks
When DoEvents is called, the control processes any available events. If no events are available, it waits for a preset period of time, and then returns.
ExchangeKeys Method (SSHServer Control)
Causes the control to exchange a new set of session keys on the specified connection.
Syntax
sshservercontrol.ExchangeKeys ConnectionId
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.
GetSSHParam Method (SSHServer Control)
Used to read a field from an SSH packet's payload.
Syntax
sshservercontrol.GetSSHParam Payload, Field
Remarks
This method is used to read the value of a particular field from an SSH packet's payload. Payload should contain the full payload of a packet received by an event such as SSHChannelRequest. Field is the name of a field to be read out of the packet.
The following is a list of the names of well-known channel request field names and their encodings:
ChannelId (int32) | The id of the channel that received the packet. |
RequestType (string) | The type of channel request. |
WantsReply (boolean) | Whether or not the client wants a reply to the request. |
The remaining fields that are available in the payload are dependent upon the value of RequestType.
pty-req
Pty-req is a request to open a pseudo terminal on the specified channel. The following fields are available:
TerminalType (string) | The type of terminal being requested (eg: "vt100"). |
TerminalWidthCharacters (int32) | The width, in characters, of the terminal to be opened. |
TerminalHeightRows (int32) | The height, in rows, of the terminal to be opened. |
TerminalWidthPixels (int32) | The width, in pixels, of the terminal to be opened. |
TerminalHeightPixels (int32) | The height, in pixels, of the terminal to be opened. |
TerminalModes (string) | A list of op-val (int32-byte) encoded modes to be used by the terminal. |
x11-req
X11-req is a request to forward x11 sessions over a channel. The following fields are available:
SingleConnection (boolean) | Disallows more than one connection to be forwarded by the channel. |
X11AuthProtocol (string) | The authentication protocol to be used (eg: "MIT-MAGIC-COOKIE-1"). |
X11AuthCookie (string) | A hexadecimal-encoded cookie to be used for authentication. |
X11ScreenNumber (int32) | The x11 screen number to be used. |
env
Env is a request to set an environment variable to be passed into a shell that may be started later. The following fields are available:
VariableName (string) | The name of the variable to be set. |
VariableValue (string) | The value of the variable to be set. |
exec
Exec is a request to execute a command on the channel using the authenticated user's shell. The following field is available:
Command (string) | The command to be executed. |
subsystem
Subsystem is a request to start a subsystem on the specified channel. The following field is available:
Subsystem (string) | The name of the subsystem to be started (eg: "sftp"). |
xon-xoff
Instructs the server to allow or disallow control-S/control-Q style flow control. The following field is available:
ClientCanDo (boolean) | Whether or not the server should enable flow control. |
signal
Sends a signal to the remote process/service. The following field is available:
SignalName (string) | The name of the signal to be sent. |
If the packet type is not well known, Field should start with the special character "%" and contain a comma-separated list of field types as defined in SetSSHParam. For example, reading out the X11AuthProtocol of an x11-req payload, you can use "%s,f".
Note: the return value is a string encoded the same way as the FieldValue param in SetSSHParam.
GetSSHParamBytes Method (SSHServer Control)
Used to read a field from an SSH packet's payload.
Syntax
sshservercontrol.GetSSHParamBytes Payload, Field
Remarks
This method is the same as calling GetSSHParam, but returns raw bytes instead of strings.
OpenChannel Method (SSHServer Control)
Opens a new SSHChannel .
Syntax
sshservercontrol.OpenChannel ConnectionId, ChannelType
Remarks
The SSH 2.0 specification allows for multiple channels to be opened over a single TCP/IP connection. The Channels property represents the channels that are currently open. A new SSHChannel can be opened with OpenChannel.
ChannelType represents the type of SSH channel to be opened. The most common type of channel is "session".
If the call to OpenChannel succeeds, an SSHChannel will be created and added to the Channels collection.
Reset Method (SSHServer Control)
Reset the control.
Syntax
sshservercontrol.Reset
Remarks
This method will reset the control's properties to their default values.
SendBytes Method (SSHServer Control)
Sends binary data to the specified channel.
Syntax
sshservercontrol.SendBytes ChannelId, Data
Remarks
This method sends binary data to the channel identified by ChannelId. To send text use the SendText method instead.
SendChannelData Method (SSHServer Control)
Used to send data over an SSH channel.
Syntax
sshservercontrol.SendChannelData ChannelId, Data
Remarks
This method can be used to send arbitrary data to the channel with the specified ChannelId.
SendSSHPacket Method (SSHServer Control)
Used to send an encoded SSH packet to the server.
Syntax
sshservercontrol.SendSSHPacket ChannelId, PacketType, Payload
Remarks
This method can be used to send a previously built SSH payload to the server. ChannelId identifies the channel that will receive the packet.
PacketType identifies what kind of packet is to be sent. Payload should contain the payload of the packet, which can be built by successive calls to SetSSHParam.
When SendSSHPacket is called, the control will finish building the packet, encrypt it for transport, and send it to the server.
SendText Method (SSHServer Control)
Sends text to the specified channel.
Syntax
sshservercontrol.SendText ChannelId, Text
Remarks
This method sends text to the client identified by ChannelId. To send binary data use the SendBytes method instead.
SetSSHParam Method (SSHServer Control)
Used to write a field to the end of a payload.
Syntax
sshservercontrol.SetSSHParam Payload, FieldType, FieldValue
Remarks
This method is used to build the payload portion of an SSH packet to be sent later by a call to SendSSHPacket. Payload should contain the result of a previous call to SetSSHParam. FieldType is a string defining the type of field to be written to the packet. FieldValue should be the string representation of the field to be written.
The following is a list of supported field types and a description of how FieldValue should be encoded:
s | A plaintext string containing the default system encoding of the data. |
sb | A string containing the hex encoded data. (eg: "A1B23C") |
m | A variable-length large integer, encoded as a textual representation of the value ("1234"). |
i | A 32-bit integer, encoded as a textual representation of the value (eg: "1234"). |
l | A 64-bit integer, encoded as a textual representation of the value (eg: "1234"). |
b | A single byte, encoded as a textual representation of the value (eg: "123"). |
f | A boolean flag, encoded as a textual representation of the value (eg: 'true' or 'false') |
Note: integer values may be encoded in hexadecimal by prefixing "0x" to the beginning of the string, otherwise the value is assumed to be base-10.
Shutdown Method (SSHServer Control)
This method shuts down the server.
Syntax
sshservercontrol.Shutdown
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 (SSHServer Control)
This method starts listening for incoming connections.
Syntax
sshservercontrol.StartListening
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 (SSHServer Control)
This method stops listening for new connections.
Syntax
sshservercontrol.StopListening
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 (SSHServer Control)
This event is fired immediately after a connection completes (or fails).
Syntax
Sub sshservercontrol_Connected(ConnectionId As Integer, StatusCode As Integer, Description As String, CertStoreType As Integer, CertStore As String, CertPassword As String, CertSubject As String)
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. The corresponding Visual Basic error code can be obtained by adding 15001 to this value.
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 control supports both public and private keys in a variety of formats. When the cstAuto value is used, the control will automatically determine the type. This property 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 (PKCS#12) file containing certificates. |
3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) 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 PKCS#7 file containing certificates. |
12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 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). |
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. |
23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface.
To use a security key, the necessary data must first be collected using the CertMgr control. The ListStoreCertificates method may be called after setting CertStoreType to cstPKCS11, CertStorePassword to the PIN, and CertStore to the full path of the PKCS#11 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 and set to the PIN. Code Example. SSH Authentication with Security Key:
|
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 designations are the most common User and Machine certificate stores in Windows:
MY | A certificate store holding personal certificates with their associated private keys. |
CA | Certifying authority certificates. |
ROOT | Root 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., PKCS#12 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 as follows:
Field | Meaning |
CN | Common Name. This is commonly a hostname like www.server.com. |
O | Organization |
OU | Organizational Unit |
L | Locality |
S | State |
C | Country |
E | Email Address |
If a field value contains a comma, it must be quoted.
ConnectionRequest Event (SSHServer Control)
This event is fired when a request for connection comes from a remote host.
Syntax
Sub sshservercontrol_ConnectionRequest(Address As String, Port As Integer, Accept As Boolean)
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.
Disconnected Event (SSHServer Control)
This event is fired when a connection is closed.
Syntax
Sub sshservercontrol_Disconnected(ConnectionId As Integer, StatusCode As Integer, Description As String)
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. The corresponding Visual Basic error code can be obtained by adding 15001 to this value.
Please refer to the Error Codes section for more information.
Error Event (SSHServer Control)
Information about errors during data delivery.
Syntax
Sub sshservercontrol_Error(ConnectionId As Integer, ErrorCode As Integer, Description As String)
Remarks
The Error event is fired in case of exceptional conditions during message processing. Normally the control fails with an error.
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.
Log Event (SSHServer Control)
Fires once for each log message.
Syntax
Sub sshservercontrol_Log(ConnectionId As Integer, LogLevel As Integer, Message As String, LogType As String)
Remarks
This event fires once for each log messages generated by the control. 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 specifies the connection to which the log message is applicable.
SSHChannelClosed Event (SSHServer Control)
Fired when a channel is closed.
Syntax
Sub sshservercontrol_SSHChannelClosed(ConnectionId As Integer, ChannelId As Integer)
Remarks
The SSHChannelClosed event is fired when a channel is closed on an SSH connection.
ConnectionId identifies the connection. ChannelId identifies the channel.
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.
SSHChannelDataIn Event (SSHServer Control)
Fired when data is received on an SSH channel.
Syntax
Sub sshservercontrol_SSHChannelDataIn(ConnectionId As Integer, ChannelId As Integer, Data As String)
Remarks
Whenever a client sends data to an SSH channel, the SSHChannelDataIn event will fire. ChannelId will identify the channel receiving data. Data will contain the raw data being received.
ConnectionId identifies the connection. ChannelId identifies the channel.
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.
SSHChannelEOF Event (SSHServer Control)
Fired when the remote peer signals the end of the data stream for the channel.
Syntax
Sub sshservercontrol_SSHChannelEOF(ConnectionId As Integer, ChannelId As Integer)
Remarks
The SSHChannelEOF event is fired when the end of the data stream for a channel on an SSH connection is reached.
ConnectionId identifies the connection. ChannelId identifies the channel.
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.
SSHChannelOpened Event (SSHServer Control)
Fired when a channel is successfully opened.
Syntax
Sub sshservercontrol_SSHChannelOpened(ConnectionId As Integer, ChannelId As Integer)
Remarks
The SSHChannelOpened event is fired when a channel is successfully opened on an SSH connection.
ConnectionId identifies the connection. ChannelId identifies the channel.
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.
SSHChannelOpenRequest Event (SSHServer Control)
Fired when a client attempts to open a new channel.
Syntax
Sub sshservercontrol_SSHChannelOpenRequest(ConnectionId As Integer, ChannelId As Integer, Service As String, Parameters As String, Accept As Boolean)
Remarks
This event is fired whenever a client attempts to open a new channel for a given connection. ChannelId will contain the id of the channel to be created. Service will identify the type of channel that is being requested (e.g.: "session"). Set Accept to true to accept the channel open request.
ConnectionId identifies the connection. ChannelId identifies the channel.
If the channel open request contains extra information, it will be contained in Parameters; you can extract data from it using GetSSHParam and GetSSHParamBytes. The most common example of a request with parameters would be a request with Service set to "direct-tcpip" (for SSH tunneling); in that case Parameters will contain the host to connect (string), the port to connect (int), the originator IP address (string) and the originator TCP port (int).
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.
SSHChannelReadyToSend Event (SSHServer Control)
Fired when the control is ready to send data.
Syntax
Sub sshservercontrol_SSHChannelReadyToSend(ConnectionId As Integer, ChannelId As Integer)
Remarks
This event fires when data can be sent over the SSH Channel specified by ChannelId for the connection specified by ConnectionId.
When a channel is opened this event will fire once the channel is ready and data can be sent.
When Timeout is set to 0 (asynchronous) sending data may result in an error if the channel or underlying socket cannot accept more data to send. Monitor SSHChannelReadyToSend or ReadyToSend to determine when data can be sent again.
When Timeout is set to a positive value the control will block when sending data until the data can be successfully sent and SSHChannelReadyToSend and ReadyToSend do not need to be monitored.
SSHChannelRequest Event (SSHServer Control)
Fired when the SSHHost sends a channel request to the client.
Syntax
Sub sshservercontrol_SSHChannelRequest(ConnectionId As Integer, ChannelId As Integer, RequestType As String, Packet As String, Success As Boolean)
Remarks
The SSHHost may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the control. However, others may need the attention of the user to be dealt with properly within the scope of the application.
ConnectionId identifies the connection.
ChannelId identifies the channel receiving the request.
Type will contain the type of the request. These types are dependent upon the type of the channel. For example, a "session" channel executing a command on the remote shell may receive an "exit-status" request containing the return code of that command.
RequestData contains the remainder of the original SSH packet. If the request type has specific parameters, they can be parsed out of this data.
Success should be used to instruct the control to respond to the request with either a success or failure notification. If the request is successful, SSHChannelRequested will fire with the same information in case the request requires further processing.
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.
SSHChannelRequested Event (SSHServer Control)
Fired if the SSHChannelRequest was successful, any further processing for the channel request should be done here.
Syntax
Sub sshservercontrol_SSHChannelRequested(ConnectionId As Integer, ChannelId As Integer, RequestType As String, Packet As String)
Remarks
The SSHHost may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the control. However, others may need the attention of the user to be dealt with properly within the scope of the application.
ConnectionId identifies the connection.
ChannelId identifies the channel receiving the request.
Type will contain the type of the request. These types are dependent upon the type of the channel. For example, a "session" channel executing a command on the remote shell may receive an "exit-status" request containing the return code of that command.
RequestData contains the remainder of the original SSH packet. If the request type has specific parameters, they can be parsed out of this data.
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.
SSHServiceRequest Event (SSHServer Control)
Fired when a client requests a service to be started.
Syntax
Sub sshservercontrol_SSHServiceRequest(ConnectionId As Integer, Service As String, Accept As Boolean)
Remarks
The SSHServiceRequest event is fired when a client requests that a service be started for a particular connection, identified by ConnectionId. Service will be the name of the service the client wishes to start. If the connection is authenticated and the user has access to the service, set Accept to true to allow the SSHServer to accept the request.
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.
SSHStatus Event (SSHServer Control)
Shows the progress of the secure connection.
Syntax
Sub sshservercontrol_SSHStatus(ConnectionId As Integer, Message As String)
Remarks
The event is fired for informational and logging purposes only. Used to track the progress of the connection.
SSHTunnelClosed Event (SSHServer Control)
This event will fire when a connected client attempts to close a tunnel.
Syntax
Sub sshservercontrol_SSHTunnelClosed(ConnectionId As Integer, Address As String, Port As Integer)
Remarks
SSHTunnelRequested Event (SSHServer Control)
This event fires when a connected client attempts to establish a forward or reverse tunnel.
Syntax
Sub sshservercontrol_SSHTunnelRequested(ConnectionId As Integer, Direction As Integer, Address As String, Port As Integer, Accept As Boolean)
Remarks
SSHUserAuthRequest Event (SSHServer Control)
Fires when a client attempts to authenticate a connection.
Syntax
Sub sshservercontrol_SSHUserAuthRequest(ConnectionId As Integer, User As String, Service As String, AuthMethod As String, AuthParam As String, Accept As Boolean, PartialSuccess As Boolean, AvailableMethods As String, KeyAlgorithm As String)
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 control 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 control:
none | This 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. |
password | AuthParam will contain the user-supplied password. If the password is correct, set Accept to true. |
publickey | AuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept or PartialSuccess to . The control will then handle verifying the digital signature and will respond to the client accordingly. |
keyboard-interactive | SSHUserAuthRequest 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. |
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.
Config Settings (SSHServer Control)
The control 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 control, access to these internal properties is provided through the Config method.SSHServer Config 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. The AltSSHCertSubject setting must be set last. When AltSSHCertSubject is set a search is initiated in the AltSSHCertStore and the certificate is loaded.
These alternative server certificate specified by these settings must be configured prior to setting Listening to . For example:
sftpserver.Config("AltSSHCertCount =1");
sftpserver.Config("AltSSHCertStoreType[0]=7"); //PEM Key Blob
sftpserver.Config("AltSSHCertStore[0]=" + ed25519Key); //PEM formatted string
sftpserver.Config("AltSSHCertSubject[0]=*"); //Load the first (and only) certificate
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 designations are the most common User and Machine certificate stores in Windows:
MY | A certificate store holding personal certificates with their associated private keys. |
CA | Certifying authority certificates. |
ROOT | Root 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., PKCS#12 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
This specifies the type of certificate store. This is used when specifying an alternate SSHCert. Possible values are:
0 | User - This is the 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 available only 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 available only 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. |
The subject of the certificate. This is used when specifying an alternative SSHCert. The special value of * may be used to select the first certificate in the store.
This setting returns a connected client's SSH version string. It may be queried inside SSHUserAuthRequest.
sftpserver1.OnSSHUserAuthRequest += (obj, ev) =>
{
Console.WriteLine(sftpserver1.Config("ClientSSHVersionString[" + ev.ConnectionId + "]"));
};
When performing public key authentication the connecting client will present both the public key itself as well as a signature to verify ownership of the corresponding private key. The control will automatically verify the signature and respond to the client to indicate whether the signature could be verified and the connection can continue. This setting controls whether an additional informational event fires to report the result of the signature verification.
If set to true, the SSHUserAuthRequest event will fire twice per public key authentication attempt. The first time the event fires for public key authentication as usual. After verification of the signature has taken place the SSHUserAuthRequest will fire again, and the AuthMethod parameter will contain the string sigstatus. The AuthParam parameter will contain a value of 0 (invalid signature) or 1 (valid signature). If the signature is invalid it will always result in a rejected authentication attempt.
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.
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")
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. |
This setting specifies the maximum amount of authentication attempts that will be allowed before forcibly disconnecting the client.
Returns whether strict key exchange (strict kex) was negotiated during the SSH handshake. This is a per-connection setting accessed by passing the ConnectionId. If strict kex is being used, then this will return "True". If strict kex is not being used, then this will return "False".
component.Config("NegotiatedStrictKex[connId]")
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 2022". When setting your own value it must begin with "SSH-2.0-" as this is a standard format that specifies the supported SSH version.
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 control will continue to send keep alive packets until SSHKeepAliveCountMax is reached. If this is reached the control will assume the connection is broken and disconnect. The default value is 5.
This setting specifies the number of seconds between keep alive packets. If set to a positive value the control 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 control uses a default value of 30.
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
- gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==
- gss-group16-sha512-toWM5Slw5Ew8Mqkay+al2g==
- gss-nistp256-sha256-toWM5Slw5Ew8Mqkay+al2g==
- gss-curve25519-sha256-toWM5Slw5Ew8Mqkay+al2g==
- gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==
- gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==
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
- umac-64@openssh.com
- umac-64-etm@openssh.com
- umac-128@openssh.com
- umac-128-etm@openssh.com
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.
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.
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-*
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.
This setting controls whether strict key exchange (strict kex) is enabled to mitigate the Terrapin attack. When enabled, the control will indicate support for strict key exchange by automatically including the pseudo-algorithm kex-strict-c-v00@openssh.com for client controls and kex-strict-s-v00@openssh.com for server controls in the list of supported key exchange algorithms.
Since both client and server must implement strict key exchange to effectively mitigate the Terrapin attack, the control provides options to further control the behavior in different scenarios. Possible values for this setting are:
0 | Disabled. Strict key exchange is not supported in the control. |
1 (default) | Enabled, but not enforced. This setting enables strict key exchange, but if the remote host does not support strict key exchange the connection is still allowed to continue. |
2 | Enabled, but reject affected algorithms if the remote host does not support strict key exchange. If the remote host supports strict key exchange all algorithms may be used. If the remote host does not support strict key exchange the connection will only continue if the selected encryption and MAC algorithms are not affected by the Terrapin attack. |
3 | Required. If the remote host does not support strict key exchange the connection will fail. |
TCPServer Config Settings
This configuration setting defines a comma-separated list of host names or IPv4 addresses that may access the control. 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.
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.
This configuration setting defines a comma-separated list of host names or IPv4 addresses that cannot access the control.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 a match, the ConnectionRequest event fires with an Accept value set to False. If no action is taken within the ConnectionRequest event, the client will not be connected.
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.
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 control 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.
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.
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.
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 control. The maximum value for this setting is 100,000 connections. Use this setting with caution. Extremely large values may affect performance. The default value is 1000.
Note: Unix/Linux operating systems limit the number of simultaneous connections to 1024.
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 control 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.
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.
When set to 0 (default), the control will use IPv4 exclusively. When set to 1, the control will use IPv6 exclusively. When set to 2, the control 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
The default code page is Unicode UTF-8 (65001).
The following is a list of valid code page identifiers:
Identifier | Name |
037 | IBM EBCDIC - U.S./Canada |
437 | OEM - United States |
500 | IBM EBCDIC - International |
708 | Arabic - ASMO 708 |
709 | Arabic - ASMO 449+, BCON V4 |
710 | Arabic - Transparent Arabic |
720 | Arabic - Transparent ASMO |
737 | OEM - Greek (formerly 437G) |
775 | OEM - Baltic |
850 | OEM - Multilingual Latin I |
852 | OEM - Latin II |
855 | OEM - Cyrillic (primarily Russian) |
857 | OEM - Turkish |
858 | OEM - Multilingual Latin I + Euro symbol |
860 | OEM - Portuguese |
861 | OEM - Icelandic |
862 | OEM - Hebrew |
863 | OEM - Canadian-French |
864 | OEM - Arabic |
865 | OEM - Nordic |
866 | OEM - Russian |
869 | OEM - Modern Greek |
870 | IBM EBCDIC - Multilingual/ROECE (Latin-2) |
874 | ANSI/OEM - Thai (same as 28605, ISO 8859-15) |
875 | IBM EBCDIC - Modern Greek |
932 | ANSI/OEM - Japanese, Shift-JIS |
936 | ANSI/OEM - Simplified Chinese (PRC, Singapore) |
949 | ANSI/OEM - Korean (Unified Hangul Code) |
950 | ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC) |
1026 | IBM EBCDIC - Turkish (Latin-5) |
1047 | IBM EBCDIC - Latin 1/Open System |
1140 | IBM EBCDIC - U.S./Canada (037 + Euro symbol) |
1141 | IBM EBCDIC - Germany (20273 + Euro symbol) |
1142 | IBM EBCDIC - Denmark/Norway (20277 + Euro symbol) |
1143 | IBM EBCDIC - Finland/Sweden (20278 + Euro symbol) |
1144 | IBM EBCDIC - Italy (20280 + Euro symbol) |
1145 | IBM EBCDIC - Latin America/Spain (20284 + Euro symbol) |
1146 | IBM EBCDIC - United Kingdom (20285 + Euro symbol) |
1147 | IBM EBCDIC - France (20297 + Euro symbol) |
1148 | IBM EBCDIC - International (500 + Euro symbol) |
1149 | IBM EBCDIC - Icelandic (20871 + Euro symbol) |
1200 | Unicode UCS-2 Little-Endian (BMP of ISO 10646) |
1201 | Unicode UCS-2 Big-Endian |
1250 | ANSI - Central European |
1251 | ANSI - Cyrillic |
1252 | ANSI - Latin I |
1253 | ANSI - Greek |
1254 | ANSI - Turkish |
1255 | ANSI - Hebrew |
1256 | ANSI - Arabic |
1257 | ANSI - Baltic |
1258 | ANSI/OEM - Vietnamese |
1361 | Korean (Johab) |
10000 | MAC - Roman |
10001 | MAC - Japanese |
10002 | MAC - Traditional Chinese (Big5) |
10003 | MAC - Korean |
10004 | MAC - Arabic |
10005 | MAC - Hebrew |
10006 | MAC - Greek I |
10007 | MAC - Cyrillic |
10008 | MAC - Simplified Chinese (GB 2312) |
10010 | MAC - Romania |
10017 | MAC - Ukraine |
10021 | MAC - Thai |
10029 | MAC - Latin II |
10079 | MAC - Icelandic |
10081 | MAC - Turkish |
10082 | MAC - Croatia |
12000 | Unicode UCS-4 Little-Endian |
12001 | Unicode UCS-4 Big-Endian |
20000 | CNS - Taiwan |
20001 | TCA - Taiwan |
20002 | Eten - Taiwan |
20003 | IBM5550 - Taiwan |
20004 | TeleText - Taiwan |
20005 | Wang - Taiwan |
20105 | IA5 IRV International Alphabet No. 5 (7-bit) |
20106 | IA5 German (7-bit) |
20107 | IA5 Swedish (7-bit) |
20108 | IA5 Norwegian (7-bit) |
20127 | US-ASCII (7-bit) |
20261 | T.61 |
20269 | ISO 6937 Non-Spacing Accent |
20273 | IBM EBCDIC - Germany |
20277 | IBM EBCDIC - Denmark/Norway |
20278 | IBM EBCDIC - Finland/Sweden |
20280 | IBM EBCDIC - Italy |
20284 | IBM EBCDIC - Latin America/Spain |
20285 | IBM EBCDIC - United Kingdom |
20290 | IBM EBCDIC - Japanese Katakana Extended |
20297 | IBM EBCDIC - France |
20420 | IBM EBCDIC - Arabic |
20423 | IBM EBCDIC - Greek |
20424 | IBM EBCDIC - Hebrew |
20833 | IBM EBCDIC - Korean Extended |
20838 | IBM EBCDIC - Thai |
20866 | Russian - KOI8-R |
20871 | IBM EBCDIC - Icelandic |
20880 | IBM EBCDIC - Cyrillic (Russian) |
20905 | IBM EBCDIC - Turkish |
20924 | IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol) |
20932 | JIS X 0208-1990 & 0121-1990 |
20936 | Simplified Chinese (GB2312) |
21025 | IBM EBCDIC - Cyrillic (Serbian, Bulgarian) |
21027 | Extended Alpha Lowercase |
21866 | Ukrainian (KOI8-U) |
28591 | ISO 8859-1 Latin I |
28592 | ISO 8859-2 Central Europe |
28593 | ISO 8859-3 Latin 3 |
28594 | ISO 8859-4 Baltic |
28595 | ISO 8859-5 Cyrillic |
28596 | ISO 8859-6 Arabic |
28597 | ISO 8859-7 Greek |
28598 | ISO 8859-8 Hebrew |
28599 | ISO 8859-9 Latin 5 |
28605 | ISO 8859-15 Latin 9 |
29001 | Europa 3 |
38598 | ISO 8859-8 Hebrew |
50220 | ISO 2022 Japanese with no halfwidth Katakana |
50221 | ISO 2022 Japanese with halfwidth Katakana |
50222 | ISO 2022 Japanese JIS X 0201-1989 |
50225 | ISO 2022 Korean |
50227 | ISO 2022 Simplified Chinese |
50229 | ISO 2022 Traditional Chinese |
50930 | Japanese (Katakana) Extended |
50931 | US/Canada and Japanese |
50933 | Korean Extended and Korean |
50935 | Simplified Chinese Extended and Simplified Chinese |
50936 | Simplified Chinese |
50937 | US/Canada and Traditional Chinese |
50939 | Japanese (Latin) Extended and Japanese |
51932 | EUC - Japanese |
51936 | EUC - Simplified Chinese |
51949 | EUC - Korean |
51950 | EUC - Traditional Chinese |
52936 | HZ-GB2312 Simplified Chinese |
54936 | Windows XP: GB18030 Simplified Chinese (4 Byte) |
57002 | ISCII Devanagari |
57003 | ISCII Bengali |
57004 | ISCII Tamil |
57005 | ISCII Telugu |
57006 | ISCII Assamese |
57007 | ISCII Oriya |
57008 | ISCII Kannada |
57009 | ISCII Malayalam |
57010 | ISCII Gujarati |
57011 | ISCII Punjabi |
65000 | Unicode UTF-7 |
65001 | Unicode UTF-8 |
Identifier | Name |
1 | ASCII |
2 | NEXTSTEP |
3 | JapaneseEUC |
4 | UTF8 |
5 | ISOLatin1 |
6 | Symbol |
7 | NonLossyASCII |
8 | ShiftJIS |
9 | ISOLatin2 |
10 | Unicode |
11 | WindowsCP1251 |
12 | WindowsCP1252 |
13 | WindowsCP1253 |
14 | WindowsCP1254 |
15 | WindowsCP1250 |
21 | ISO2022JP |
30 | MacOSRoman |
10 | UTF16String |
0x90000100 | UTF16BigEndian |
0x94000100 | UTF16LittleEndian |
0x8c000100 | UTF32String |
0x98000100 | UTF32BigEndian |
0x9c000100 | UTF32LittleEndian |
65536 | Proprietary |
In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to to mask sensitive data. The default is .
This setting only works on these controls: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.
When set to , the control will use the system security libraries by default to perform cryptographic functions where applicable.
Setting this configuration setting to tells the control to use the internal implementation instead of using the system security libraries.
This setting is set to by default on all platforms.
Trappable Errors (SSHServer Control)
SSHServer Errors
21202 Could not forward connection. A detailed message follows. | |
21203 Could not forward connection/channel data. A detailed message follows. | |
21301 Could not authenticate client. | |
21302 No server certificate was specified or no private key found. |
TCPServer Errors
20101 You cannot change the RemotePort at this time. A connection is in progress. | |
20102 You cannot change the RemoteHost at this time. A connection is in progress. | |
20103 The RemoteHost address is invalid (0.0.0.0). | |
20105 TCPServer is already listening. | |
20107 Cannot change LocalPort when TCPServer is listening. | |
20108 Cannot change LocalHost when TCPServer is listening. | |
20109 Cannot change MaxConnections when TCPServer is listening. | |
20113 You cannot change MaxLineLength at this time. A connection is in progress. | |
20117 RemotePort cannot be zero. Please specify a valid service port number. | |
20127 Invalid ConnectionId. | |
20136 Operation would block. |
TCP/IP Errors
25005 [10004] Interrupted system call. | |
25010 [10009] Bad file number. | |
25014 [10013] Access denied. | |
25015 [10014] Bad address. | |
25023 [10022] Invalid argument. | |
25025 [10024] Too many open files. | |
25036 [10035] Operation would block. | |
25037 [10036] Operation now in progress. | |
25038 [10037] Operation already in progress. | |
25039 [10038] Socket operation on non-socket. | |
25040 [10039] Destination address required. | |
25041 [10040] Message too long. | |
25042 [10041] Protocol wrong type for socket. | |
25043 [10042] Bad protocol option. | |
25044 [10043] Protocol not supported. | |
25045 [10044] Socket type not supported. | |
25046 [10045] Operation not supported on socket. | |
25047 [10046] Protocol family not supported. | |
25048 [10047] Address family not supported by protocol family. | |
25049 [10048] Address already in use. | |
25050 [10049] Can't assign requested address. | |
25051 [10050] Network is down. | |
25052 [10051] Network is unreachable. | |
25053 [10052] Net dropped connection or reset. | |
25054 [10053] Software caused connection abort. | |
25055 [10054] Connection reset by peer. | |
25056 [10055] No buffer space available. | |
25057 [10056] Socket is already connected. | |
25058 [10057] Socket is not connected. | |
25059 [10058] Can't send after socket shutdown. | |
25060 [10059] Too many references, can't splice. | |
25061 [10060] Connection timed out. | |
25062 [10061] Connection refused. | |
25063 [10062] Too many levels of symbolic links. | |
25064 [10063] File name too long. | |
25065 [10064] Host is down. | |
25066 [10065] No route to host. | |
25067 [10066] Directory not empty | |
25068 [10067] Too many processes. | |
25069 [10068] Too many users. | |
25070 [10069] Disc Quota Exceeded. | |
25071 [10070] Stale NFS file handle. | |
25072 [10071] Too many levels of remote in path. | |
25092 [10091] Network subsystem is unavailable. | |
25093 [10092] WINSOCK DLL Version out of range. | |
25094 [10093] Winsock not loaded yet. | |
26002 [11001] Host not found. | |
26003 [11002] Non-authoritative 'Host not found' (try again or check DNS setup). | |
26004 [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP. | |
26005 [11004] Valid name, no data record (check DNS setup). |