SSHReverseTunnel Class

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The SSHReverseTunnel class provides a simple way to establish a reverse tunnel with a Secure Shell (SSH) host.

Syntax

class ipworksssh.SSHReverseTunnel

Remarks

The SSHReverseTunnel class may be used to establish a reverse tunnel with a Secure Shell (SSH) host. The SSH host will listen for incoming connections on the specified port and forward traffic to the class through the SSH tunnel.

The ssh_host and ssh_port properties specify which Secure Shell (SSH) server to use. The ssh_user and ssh_password properties allow the client to authenticate itself with the server. The on_ssh_server_authentication event or ssh_accept_server_host_key property allow you to check the server identity. Finally, the on_ssh_status event provides information about the SSH handshake.

To begin, call ssh_logon to connect to the SSH host. After this method returns, the connectionto the SSH server is successfully established. Call request_forwarding to establish a reverse tunnel. This method takes parameters to tell the SSH host on which port to listen.

The class has two modes that allow data to be dealt with directly from the events, or automatically forwarded on to a different endpoint.

Event Based Operation

In this mode, any data received by the class over the tunnel causes the events of the class to fire. For instance:

SSHReverseTunnel.RequestForwarding("0.0.0.0", 777, "", 0);

In the above code, forwarding is requested from port 777 on the ssh_host. Any data received on port 777 by the ssh_host will be sent to the class. In the above code, the last two parameters are empty and 0, indicating to the class that no local forwarding is requested.

Once request_forwarding returns, the Secure Shell (SSH) reverse tunnel is established. Any connection made to the SSH host on the specified port will then trigger the class's events to fire, allowing you to handle the connection request and data.

When a client connects to the SSH host on the specified port, the on_ssh_channel_open_request event will fire. Within this event, choose to accept or reject the connection by setting the Accept parameter. This event contains details about the connection that may be used when determining whether to accept the connection.

After the channel is established, data are received through the on_ssh_channel_data event. Call the send_channel_data method to send data over the channel, and call the close_channel method to close the channel.

Local Forwarding

In this mode, any data received by the class is automatically forwarded to a separate endpoint. This allows the class to act as a sort of proxy. There is no need to handle data directly in this case. For instance: SSHReverseTunnel.RequestForwarding("0.0.0.0", 777, "nsoftware.com", 80);

In the above code, forwarding is requested from port 777 on ssh_host. The class is instructed to establish a connection to "nsoftware.com" on port 80 when a client connects to ssh_host on port 777. Any data received from the client connected to ssh_host on port 777 will automatically be forwarded to "nsoftware.com" on port 80. Any data received back from "nsoftware.com" on port 80 will be sent back to the connected client.

In this mode, data may flow freely from the client connected to the ssh_host to the endpoint specified in the request_forwarding method without any additional code required.

Note: The following events are applicable when a connection is made to the SSH host:

To stop a previously established reverse tunnel, call the cancel_forwarding method.

Property List


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

ssh_channel_countThe number of records in the arrays.
bytes_sentThis property specifies the number of bytes actually sent after a sending channel data.
channel_idThis property provides an Id generated by the class to identify the current Secure Shell (SSH) channel.
connected_addressThis property holds the remote address to which the connection was established.
connected_portThis property holds the remote port to which the connection was established.
forwarding_hostThis property holds the host to which incoming traffic is forwarded.
forwarding_portThis property holds the port to which incoming traffic is forwarded.
origin_addressThis property holds the address of the client that originated the connection to the reverse tunnel on SSHHost .
origin_portThis property holds the port used by the client that originated the connection to the reverse tunnel on SSHHost .
serviceThis property holds the channel type that was requested when opening the channel.
connectedThe class to be connected.
firewall_auto_detectWhether to automatically detect and use firewall system settings, if available.
firewall_typeThe type of firewall to connect through.
firewall_hostThe name or IP address of the firewall (optional).
firewall_passwordA password if authentication is to be used when connecting through the firewall.
firewall_portThe Transmission Control Protocol (TCP) port for the firewall Host .
firewall_userA username if authentication is to be used when connecting through a firewall.
local_hostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
local_portThe TCP port in the local host where the class binds.
ssh_accept_server_host_key_effective_dateThe date on which this certificate becomes valid.
ssh_accept_server_host_key_expiration_dateThe date on which the certificate expires.
ssh_accept_server_host_key_extended_key_usageA comma-delimited list of extended key usage identifiers.
ssh_accept_server_host_key_fingerprintThe hex-encoded, 16-byte MD5 fingerprint of the certificate.
ssh_accept_server_host_key_fingerprint_sha1The hex-encoded, 20-byte SHA-1 fingerprint of the certificate.
ssh_accept_server_host_key_fingerprint_sha256The hex-encoded, 32-byte SHA-256 fingerprint of the certificate.
ssh_accept_server_host_key_issuerThe issuer of the certificate.
ssh_accept_server_host_key_private_keyThe private key of the certificate (if available).
ssh_accept_server_host_key_private_key_availableWhether a PrivateKey is available for the selected certificate.
ssh_accept_server_host_key_private_key_containerThe name of the PrivateKey container for the certificate (if available).
ssh_accept_server_host_key_public_keyThe public key of the certificate.
ssh_accept_server_host_key_public_key_algorithmThe textual description of the certificate's public key algorithm.
ssh_accept_server_host_key_public_key_lengthThe length of the certificate's public key (in bits).
ssh_accept_server_host_key_serial_numberThe serial number of the certificate encoded as a string.
ssh_accept_server_host_key_signature_algorithmThe text description of the certificate's signature algorithm.
ssh_accept_server_host_key_storeThe name of the certificate store for the client certificate.
ssh_accept_server_host_key_store_passwordIf the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
ssh_accept_server_host_key_store_typeThe type of certificate store for this certificate.
ssh_accept_server_host_key_subject_alt_namesComma-separated lists of alternative subject names for the certificate.
ssh_accept_server_host_key_thumbprint_md5The MD5 hash of the certificate.
ssh_accept_server_host_key_thumbprint_sha1The SHA-1 hash of the certificate.
ssh_accept_server_host_key_thumbprint_sha256The SHA-256 hash of the certificate.
ssh_accept_server_host_key_usageThe text description of UsageFlags .
ssh_accept_server_host_key_usage_flagsThe flags that show intended use for the certificate.
ssh_accept_server_host_key_versionThe certificate's version number.
ssh_accept_server_host_key_subjectThe subject of the certificate used for client authentication.
ssh_accept_server_host_key_encodedThe certificate (PEM/Base64 encoded).
ssh_auth_modeThe authentication method to be used with the class when calling SSHLogon .
ssh_cert_effective_dateThe date on which this certificate becomes valid.
ssh_cert_expiration_dateThe date on which the certificate expires.
ssh_cert_extended_key_usageA comma-delimited list of extended key usage identifiers.
ssh_cert_fingerprintThe hex-encoded, 16-byte MD5 fingerprint of the certificate.
ssh_cert_fingerprint_sha1The hex-encoded, 20-byte SHA-1 fingerprint of the certificate.
ssh_cert_fingerprint_sha256The hex-encoded, 32-byte SHA-256 fingerprint of the certificate.
ssh_cert_issuerThe issuer of the certificate.
ssh_cert_private_keyThe private key of the certificate (if available).
ssh_cert_private_key_availableWhether a PrivateKey is available for the selected certificate.
ssh_cert_private_key_containerThe name of the PrivateKey container for the certificate (if available).
ssh_cert_public_keyThe public key of the certificate.
ssh_cert_public_key_algorithmThe textual description of the certificate's public key algorithm.
ssh_cert_public_key_lengthThe length of the certificate's public key (in bits).
ssh_cert_serial_numberThe serial number of the certificate encoded as a string.
ssh_cert_signature_algorithmThe text description of the certificate's signature algorithm.
ssh_cert_storeThe name of the certificate store for the client certificate.
ssh_cert_store_passwordIf the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
ssh_cert_store_typeThe type of certificate store for this certificate.
ssh_cert_subject_alt_namesComma-separated lists of alternative subject names for the certificate.
ssh_cert_thumbprint_md5The MD5 hash of the certificate.
ssh_cert_thumbprint_sha1The SHA-1 hash of the certificate.
ssh_cert_thumbprint_sha256The SHA-256 hash of the certificate.
ssh_cert_usageThe text description of UsageFlags .
ssh_cert_usage_flagsThe flags that show intended use for the certificate.
ssh_cert_versionThe certificate's version number.
ssh_cert_subjectThe subject of the certificate used for client authentication.
ssh_cert_encodedThe certificate (PEM/Base64 encoded).
ssh_compression_algorithmsThe comma-separated list containing all allowable compression algorithms.
ssh_encryption_algorithmsThe comma-separated list containing all allowable encryption algorithms.
ssh_hostThe address of the Secure Shell (SSH) host.
ssh_passwordThe password for Secure Shell (SSH) password-based authentication.
ssh_portThe port on the Secure Shell (SSH) server where the SSH service is running; by default, 22.
ssh_userThe username for Secure Shell (SSH) authentication.
timeoutThis property includes the timeout for the class.

Method List


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

cancel_forwardingRequests the server to stop forwarding a remote Transmission Control Protocol (TCP)/IP port.
close_channelCloses a existing SSHChannel .
configSets or retrieves a configuration setting.
decode_packetDecodes a hex-encoded Secure Shell (SSH) packet.
do_eventsThis method processes events from the internal message queue.
encode_packetHex encodes a Secure Shell (SSH) packet.
exchange_keysCauses the class to exchange a new set of session keys with the SSHHost .
get_ssh_paramReads a field from a Secure Shell (SSH) packet's payload.
get_ssh_param_bytesReads a field from a Secure Shell (SSH) packet's payload.
request_forwardingRequests the server to forward a remote Transmission Control Protocol (TCP)/IP port.
resetThis method will reset the class.
send_channel_dataSends data over a Secure Shell (SSH) channel.
set_ssh_paramWrites a field to the end of a payload.
ssh_logoffLogs off from the Secure Shell (SSH) server.
ssh_logonLogs on to the SSHHost using the current SSHUser and SSHPassword .

Event List


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

on_connectedFired immediately after a connection completes (or fails).
on_connection_statusFired to indicate changes in the connection state.
on_disconnectedFired when a connection is closed.
on_errorFired when information is available about errors during data delivery.
on_logFired once for each log message.
on_reconnect_attemptFired when attempting to reconnect.
on_ssh_channel_closedFired when a channel is closed.
on_ssh_channel_dataFired when the SSHHost sends channel data to the client.
on_ssh_channel_eofFired when the remote peer signals the end of the data stream for the channel.
on_ssh_channel_openedFired when a channel is successfully opened.
on_ssh_channel_open_requestFired when the peer attempts to open a new channel.
on_ssh_channel_ready_to_sendFired when the class is ready to send data.
on_ssh_channel_requestFired when the SSHHost sends a channel request to the client.
on_ssh_channel_requestedFired if the SSHChannelRequest was successful; any further processing for the channel request should be done here.
on_ssh_custom_authFired when the class is doing a custom authentication.
on_ssh_keyboard_interactiveFired when the class receives a request for user input from the server.
on_ssh_server_authenticationFired after the server presents its public key to the client.
on_ssh_statusFired to track the progress of the secure connection.

Config Settings


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

AutoReconnectWhether to automatically reconnect.
DefaultChannelIdleTimeoutThe inactivity timeout for channels.
ForwardedPortThe remote port which is forwarded.
ForwardingLocalHostThe interface on which to bind when forwarding data.
MaxRetryCountThe maximum number of retries when reconnecting.
RetryIntervalThe interval in seconds between reconnect attempts.
ChannelDataEOL[ChannelId]Used to break the incoming data stream into chunks.
ChannelDataEOLFound[ChannelId]Determines if ChannelDataEOL was found.
ClientSSHVersionStringThe SSH version string used by the class.
DoNotRepeatAuthMethodsWhether the class will repeat authentication methods during multifactor authentication.
EnablePageantAuthWhether to use a key stored in Pageant to perform client authentication.
KerberosDelegationIf true, asks for credentials with delegation enabled during authentication.
KerberosRealmThe fully qualified domain name of the Kerberos Realm to use for GSSAPI authentication.
KerberosSPNThe Kerberos Service Principal Name of the SSH host.
KeyRenegotiationThresholdSets the threshold for the SSH Key Renegotiation.
LogLevelSpecifies the level of detail that is logged.
MaxChannelDataLength[ChannelId]The maximum amount of data to accumulate when no ChannelDataEOL is found.
MaxPacketSizeThe maximum packet size of the channel, in bytes.
MaxWindowSizeThe maximum window size allowed for the channel, in bytes.
NegotiatedStrictKexReturns whether strict key exchange was negotiated to be used.
PasswordPromptThe text of the password prompt used in keyboard-interactive authentication.
PreferredDHGroupBitsThe size (in bits) of the preferred modulus (p) to request from the server.
RecordLengthThe length of received data records.
ServerSSHVersionStringThe remote host's SSH version string.
SignedSSHCertThe CA signed client public key used when authenticating.
SSHAcceptAnyServerHostKeyIf set the class will accept any key presented by the server.
SSHAcceptServerCAKeyThe CA public key that signed the server's host key.
SSHAcceptServerHostKeyFingerPrintThe fingerprint of the server key to accept.
SSHFingerprintHashAlgorithmThe algorithm used to calculate the fingerprint.
SSHFingerprintMD5The server hostkey's MD5 fingerprint.
SSHFingerprintSHA1The server hostkey's SHA1 fingerprint.
SSHFingerprintSHA256The server hostkey's SHA256 fingerprint.
SSHKeepAliveCountMaxThe maximum number of keep alive packets to send without a response.
SSHKeepAliveIntervalThe interval between keep alive packets.
SSHKeyExchangeAlgorithmsSpecifies the supported key exchange algorithms.
SSHKeyRenegotiateCauses the class to renegotiate the SSH keys.
SSHMacAlgorithmsSpecifies the supported Mac algorithms.
SSHPubKeyAuthSigAlgorithmsSpecifies the enabled signature algorithms that may be used when attempting public key authentication.
SSHPublicKeyAlgorithmsSpecifies the supported public key algorithms for the server's public key.
SSHVersionPatternThe pattern used to match the remote host's version string.
TryAllAvailableAuthMethodsIf set to true, the class will try all available authentication methods.
UseStrictKeyExchangeSpecifies how strict key exchange is supported.
WaitForChannelCloseWhether to wait for channels to be closed before disconnected.
WaitForServerDisconnectWhether to wait for the server to close the connection.
ConnectionTimeoutSets a separate timeout value for establishing a connection.
FirewallAutoDetectTells the class whether or not to automatically detect and use firewall system settings, if available.
FirewallHostName or IP address of firewall (optional).
FirewallPasswordPassword to be used if authentication is to be used when connecting through the firewall.
FirewallPortThe TCP port for the FirewallHost;.
FirewallTypeDetermines the type of firewall to connect through.
FirewallUserA user name if authentication is to be used connecting through a firewall.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
LingerWhen set to True, connections are terminated gracefully.
LingerTimeTime in seconds to have the connection linger.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the class binds.
MaxLineLengthThe maximum amount of data to accumulate when no EOL is found.
MaxTransferRateThe transfer rate limit in bytes per second.
ProxyExceptionsListA semicolon separated list of hosts and IPs to bypass when using a proxy.
TCPKeepAliveDetermines whether or not the keep alive socket option is enabled.
TcpNoDelayWhether or not to delay when sending packets.
UseIPv6Whether to use IPv6.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
MaskSensitiveDataWhether sensitive data is masked in log messages.
ProcessIdleEventsWhether the class uses its internal event loop to process events when the main thread is idle.
SelectWaitMillisThe length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.
UseFIPSCompliantAPITells the class whether or not to use FIPS certified APIs.
UseInternalSecurityAPIWhether or not to use the system security libraries or an internal implementation.

ssh_channel_count Property

The number of records in the arrays.

Syntax

def get_ssh_channel_count() -> int: ...

ssh_channel_count = property(get_ssh_channel_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

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

This property is read-only.

bytes_sent Property

This property specifies the number of bytes actually sent after a sending channel data.

Syntax

def get_bytes_sent(ssh_channel_id: int) -> int: ...

Default Value

0

Remarks

This property specifies the number of bytes actually sent after a sending channel data.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

channel_id Property

This property provides an Id generated by the class to identify the current Secure Shell (SSH) channel.

Syntax

def get_channel_id(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property provides an Id generated by the class to identify the current Secure Shell (SSH) channel.

This Id is unique to this channel.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

connected_address Property

This property holds the remote address to which the connection was established.

Syntax

def get_connected_address(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property holds the remote address to which the connection was established. This should match the Address parameter passed to the requestforwarding method.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

connected_port Property

This property holds the remote port to which the connection was established.

Syntax

def get_connected_port(ssh_channel_id: int) -> int: ...

Default Value

0

Remarks

This property holds the remote port to which the connection was established. This should match the Port parameter passed to the requestforwarding method.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

forwarding_host Property

This property holds the host to which incoming traffic is forwarded.

Syntax

def get_forwarding_host(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property holds the host to which incoming traffic is forwarded. This is applicable only if local forwarding was requested when calling requestforwarding.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

forwarding_port Property

This property holds the port to which incoming traffic is forwarded.

Syntax

def get_forwarding_port(ssh_channel_id: int) -> int: ...

Default Value

0

Remarks

This property holds the port to which incoming traffic is forwarded. This is applicable only if local forwarding was requested when calling requestforwarding.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

origin_address Property

This property holds the address of the client that originated the connection to the reverse tunnel on SSHHost .

Syntax

def get_origin_address(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property holds the address of the client that originated the connection to the reverse tunnel on sshhost.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

origin_port Property

This property holds the port used by the client that originated the connection to the reverse tunnel on SSHHost .

Syntax

def get_origin_port(ssh_channel_id: int) -> int: ...

Default Value

0

Remarks

This property holds the port used by the client that originated the connection to the reverse tunnel on sshhost.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

service Property

This property holds the channel type that was requested when opening the channel.

Syntax

def get_service(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property holds the channel type that was requested when opening the channel. For instance "session" or "forwarded-tcpip".

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

connected Property

The class to be connected.

Syntax

def get_connected() -> bool: ...

connected = property(get_connected, None)

Default Value

FALSE

Remarks

This property is used to determine whether or not the class is connected to the remote host. Use the ssh_logon and ssh_logoff methods to manage the connection.

This property is read-only.

firewall_auto_detect Property

Whether to automatically detect and use firewall system settings, if available.

Syntax

def get_firewall_auto_detect() -> bool: ...
def set_firewall_auto_detect(value: bool) -> None: ...

firewall_auto_detect = property(get_firewall_auto_detect, set_firewall_auto_detect)

Default Value

FALSE

Remarks

Whether to automatically detect and use firewall system settings, if available.

firewall_type Property

The type of firewall to connect through.

Syntax

def get_firewall_type() -> int: ...
def set_firewall_type(value: int) -> None: ...

firewall_type = property(get_firewall_type, set_firewall_type)

Default Value

0

Remarks

The type of firewall to connect through. The applicable values are as follows:

fwNone (0)No firewall (default setting).
fwTunnel (1)Connect through a tunneling proxy. firewall_port is set to 80.
fwSOCKS4 (2)Connect through a SOCKS4 Proxy. firewall_port is set to 1080.
fwSOCKS5 (3)Connect through a SOCKS5 Proxy. firewall_port is set to 1080.
fwSOCKS4A (10)Connect through a SOCKS4A Proxy. firewall_port is set to 1080.

firewall_host Property

The name or IP address of the firewall (optional).

Syntax

def get_firewall_host() -> str: ...
def set_firewall_host(value: str) -> None: ...

firewall_host = property(get_firewall_host, set_firewall_host)

Default Value

""

Remarks

The name or IP address of the firewall (optional). If a firewall_host is given, the requested connections will be authenticated through the specified firewall when connecting.

If this property is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, this property is set to the corresponding address. If the search is not successful, the class fails with an error.

firewall_password Property

A password if authentication is to be used when connecting through the firewall.

Syntax

def get_firewall_password() -> str: ...
def set_firewall_password(value: str) -> None: ...

firewall_password = property(get_firewall_password, set_firewall_password)

Default Value

""

Remarks

A password if authentication is to be used when connecting through the firewall. If firewall_host is specified, the firewall_user and firewall_password properties are used to connect and authenticate to the given firewall. If the authentication fails, the class fails with an error.

firewall_port Property

The Transmission Control Protocol (TCP) port for the firewall Host .

Syntax

def get_firewall_port() -> int: ...
def set_firewall_port(value: int) -> None: ...

firewall_port = property(get_firewall_port, set_firewall_port)

Default Value

0

Remarks

The Transmission Control Protocol (TCP) port for the firewall firewall_host. See the description of the firewall_host property for details.

Note: This property is set automatically when firewall_type is set to a valid value. See the description of the firewall_type property for details.

firewall_user Property

A username if authentication is to be used when connecting through a firewall.

Syntax

def get_firewall_user() -> str: ...
def set_firewall_user(value: str) -> None: ...

firewall_user = property(get_firewall_user, set_firewall_user)

Default Value

""

Remarks

A username if authentication is to be used when connecting through a firewall. If firewall_host is specified, this property and the firewall_password property are used to connect and authenticate to the given Firewall. If the authentication fails, the class fails with an error.

local_host Property

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

Syntax

def get_local_host() -> str: ...
def set_local_host(value: str) -> None: ...

local_host = property(get_local_host, set_local_host)

Default Value

""

Remarks

This 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 multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the class is connected, the local_host 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 multihomed hosts (machines with more than one IP interface).

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

local_port Property

The TCP port in the local host where the class binds.

Syntax

def get_local_port() -> int: ...
def set_local_port(value: int) -> None: ...

local_port = property(get_local_port, set_local_port)

Default Value

0

Remarks

This property must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this property to 0 (default) enables the system to choose an open port at random. The chosen port will be returned by the local_port property after the connection is established.

local_port cannot be changed once a connection is made. Any attempt to set this property when a connection is active will generate an error.

This property is useful when trying to connect to services that require a trusted port on the client side.

ssh_accept_server_host_key_effective_date Property

The date on which this certificate becomes valid.

Syntax

def get_ssh_accept_server_host_key_effective_date() -> str: ...

ssh_accept_server_host_key_effective_date = property(get_ssh_accept_server_host_key_effective_date, None)

Default Value

""

Remarks

The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

This property is read-only.

ssh_accept_server_host_key_expiration_date Property

The date on which the certificate expires.

Syntax

def get_ssh_accept_server_host_key_expiration_date() -> str: ...

ssh_accept_server_host_key_expiration_date = property(get_ssh_accept_server_host_key_expiration_date, None)

Default Value

""

Remarks

The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

This property is read-only.

ssh_accept_server_host_key_extended_key_usage Property

A comma-delimited list of extended key usage identifiers.

Syntax

def get_ssh_accept_server_host_key_extended_key_usage() -> str: ...

ssh_accept_server_host_key_extended_key_usage = property(get_ssh_accept_server_host_key_extended_key_usage, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_fingerprint Property

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

Syntax

def get_ssh_accept_server_host_key_fingerprint() -> str: ...

ssh_accept_server_host_key_fingerprint = property(get_ssh_accept_server_host_key_fingerprint, None)

Default Value

""

Remarks

The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_accept_server_host_key_fingerprint_sha1 Property

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

Syntax

def get_ssh_accept_server_host_key_fingerprint_sha1() -> str: ...

ssh_accept_server_host_key_fingerprint_sha1 = property(get_ssh_accept_server_host_key_fingerprint_sha1, None)

Default Value

""

Remarks

The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_accept_server_host_key_fingerprint_sha256 Property

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

Syntax

def get_ssh_accept_server_host_key_fingerprint_sha256() -> str: ...

ssh_accept_server_host_key_fingerprint_sha256 = property(get_ssh_accept_server_host_key_fingerprint_sha256, None)

Default Value

""

Remarks

The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_accept_server_host_key_issuer Property

The issuer of the certificate.

Syntax

def get_ssh_accept_server_host_key_issuer() -> str: ...

ssh_accept_server_host_key_issuer = property(get_ssh_accept_server_host_key_issuer, None)

Default Value

""

Remarks

The issuer of the certificate. This property contains a string representation of the name of the issuing authority for the certificate.

This property is read-only.

ssh_accept_server_host_key_private_key Property

The private key of the certificate (if available).

Syntax

def get_ssh_accept_server_host_key_private_key() -> str: ...

ssh_accept_server_host_key_private_key = property(get_ssh_accept_server_host_key_private_key, None)

Default Value

""

Remarks

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

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

This property is read-only.

ssh_accept_server_host_key_private_key_available Property

Whether a PrivateKey is available for the selected certificate.

Syntax

def get_ssh_accept_server_host_key_private_key_available() -> bool: ...

ssh_accept_server_host_key_private_key_available = property(get_ssh_accept_server_host_key_private_key_available, None)

Default Value

FALSE

Remarks

Whether a ssh_accept_server_host_key_private_key is available for the selected certificate. If ssh_accept_server_host_key_private_key_available is True, the certificate may be used for authentication purposes (e.g., server authentication).

This property is read-only.

ssh_accept_server_host_key_private_key_container Property

The name of the PrivateKey container for the certificate (if available).

Syntax

def get_ssh_accept_server_host_key_private_key_container() -> str: ...

ssh_accept_server_host_key_private_key_container = property(get_ssh_accept_server_host_key_private_key_container, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_public_key Property

The public key of the certificate.

Syntax

def get_ssh_accept_server_host_key_public_key() -> str: ...

ssh_accept_server_host_key_public_key = property(get_ssh_accept_server_host_key_public_key, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_public_key_algorithm Property

The textual description of the certificate's public key algorithm.

Syntax

def get_ssh_accept_server_host_key_public_key_algorithm() -> str: ...

ssh_accept_server_host_key_public_key_algorithm = property(get_ssh_accept_server_host_key_public_key_algorithm, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_public_key_length Property

The length of the certificate's public key (in bits).

Syntax

def get_ssh_accept_server_host_key_public_key_length() -> int: ...

ssh_accept_server_host_key_public_key_length = property(get_ssh_accept_server_host_key_public_key_length, None)

Default Value

0

Remarks

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

This property is read-only.

ssh_accept_server_host_key_serial_number Property

The serial number of the certificate encoded as a string.

Syntax

def get_ssh_accept_server_host_key_serial_number() -> str: ...

ssh_accept_server_host_key_serial_number = property(get_ssh_accept_server_host_key_serial_number, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_signature_algorithm Property

The text description of the certificate's signature algorithm.

Syntax

def get_ssh_accept_server_host_key_signature_algorithm() -> str: ...

ssh_accept_server_host_key_signature_algorithm = property(get_ssh_accept_server_host_key_signature_algorithm, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_store Property

The name of the certificate store for the client certificate.

Syntax

def get_ssh_accept_server_host_key_store() -> bytes: ...
def set_ssh_accept_server_host_key_store(value: bytes) -> None: ...

ssh_accept_server_host_key_store = property(get_ssh_accept_server_host_key_store, set_ssh_accept_server_host_key_store)

Default Value

"MY"

Remarks

The name of the certificate store for the client certificate.

The ssh_accept_server_host_key_store_type property denotes the type of the certificate store specified by ssh_accept_server_host_key_store. If the store is password-protected, specify the password in ssh_accept_server_host_key_store_password.

ssh_accept_server_host_key_store is used in conjunction with the ssh_accept_server_host_key_subject property to specify client certificates. If ssh_accept_server_host_key_store has a value, and ssh_accept_server_host_key_subject or ssh_accept_server_host_key_encoded is set, a search for a certificate is initiated. Please see the ssh_accept_server_host_key_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:

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

When the certificate store type is cstPFXFile, this property must be set to the name of the file. When the type is cstPFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

ssh_accept_server_host_key_store_password Property

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

Syntax

def get_ssh_accept_server_host_key_store_password() -> str: ...
def set_ssh_accept_server_host_key_store_password(value: str) -> None: ...

ssh_accept_server_host_key_store_password = property(get_ssh_accept_server_host_key_store_password, set_ssh_accept_server_host_key_store_password)

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.

ssh_accept_server_host_key_store_type Property

The type of certificate store for this certificate.

Syntax

def get_ssh_accept_server_host_key_store_type() -> int: ...
def set_ssh_accept_server_host_key_store_type(value: int) -> None: ...

ssh_accept_server_host_key_store_type = property(get_ssh_accept_server_host_key_store_type, set_ssh_accept_server_host_key_store_type)

Default Value

0

Remarks

The type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class 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 class. The list_store_certificates method may be called after setting cert_store_type to cstPKCS11, cert_store_password to the PIN, and cert_store to the full path of the PKCS#11 DLL. The certificate information returned in the on_cert_list event's CertEncoded parameter may be saved for later use.

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

Code Example. SSH Authentication with Security Key: certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

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.

ssh_accept_server_host_key_subject_alt_names Property

Comma-separated lists of alternative subject names for the certificate.

Syntax

def get_ssh_accept_server_host_key_subject_alt_names() -> str: ...

ssh_accept_server_host_key_subject_alt_names = property(get_ssh_accept_server_host_key_subject_alt_names, None)

Default Value

""

Remarks

Comma-separated lists of alternative subject names for the certificate.

This property is read-only.

ssh_accept_server_host_key_thumbprint_md5 Property

The MD5 hash of the certificate.

Syntax

def get_ssh_accept_server_host_key_thumbprint_md5() -> str: ...

ssh_accept_server_host_key_thumbprint_md5 = property(get_ssh_accept_server_host_key_thumbprint_md5, None)

Default Value

""

Remarks

The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_accept_server_host_key_thumbprint_sha1 Property

The SHA-1 hash of the certificate.

Syntax

def get_ssh_accept_server_host_key_thumbprint_sha1() -> str: ...

ssh_accept_server_host_key_thumbprint_sha1 = property(get_ssh_accept_server_host_key_thumbprint_sha1, None)

Default Value

""

Remarks

The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_accept_server_host_key_thumbprint_sha256 Property

The SHA-256 hash of the certificate.

Syntax

def get_ssh_accept_server_host_key_thumbprint_sha256() -> str: ...

ssh_accept_server_host_key_thumbprint_sha256 = property(get_ssh_accept_server_host_key_thumbprint_sha256, None)

Default Value

""

Remarks

The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_accept_server_host_key_usage Property

The text description of UsageFlags .

Syntax

def get_ssh_accept_server_host_key_usage() -> str: ...

ssh_accept_server_host_key_usage = property(get_ssh_accept_server_host_key_usage, None)

Default Value

""

Remarks

The text description of ssh_accept_server_host_key_usage_flags.

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

  • Digital Signature
  • Non-Repudiation
  • Key Encipherment
  • Data Encipherment
  • Key Agreement
  • Certificate Signing
  • CRL Signing
  • Encipher Only

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

This property is read-only.

ssh_accept_server_host_key_usage_flags Property

The flags that show intended use for the certificate.

Syntax

def get_ssh_accept_server_host_key_usage_flags() -> int: ...

ssh_accept_server_host_key_usage_flags = property(get_ssh_accept_server_host_key_usage_flags, None)

Default Value

0

Remarks

The flags that show intended use for the certificate. The value of ssh_accept_server_host_key_usage_flags is a combination of the following flags:

0x80Digital Signature
0x40Non-Repudiation
0x20Key Encipherment
0x10Data Encipherment
0x08Key Agreement
0x04Certificate Signing
0x02CRL Signing
0x01Encipher Only

Please see the ssh_accept_server_host_key_usage property for a text representation of ssh_accept_server_host_key_usage_flags.

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

This property is read-only.

ssh_accept_server_host_key_version Property

The certificate's version number.

Syntax

def get_ssh_accept_server_host_key_version() -> str: ...

ssh_accept_server_host_key_version = property(get_ssh_accept_server_host_key_version, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_accept_server_host_key_subject Property

The subject of the certificate used for client authentication.

Syntax

def get_ssh_accept_server_host_key_subject() -> str: ...
def set_ssh_accept_server_host_key_subject(value: str) -> None: ...

ssh_accept_server_host_key_subject = property(get_ssh_accept_server_host_key_subject, set_ssh_accept_server_host_key_subject)

Default Value

""

Remarks

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:

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

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

ssh_accept_server_host_key_encoded Property

The certificate (PEM/Base64 encoded).

Syntax

def get_ssh_accept_server_host_key_encoded() -> bytes: ...
def set_ssh_accept_server_host_key_encoded(value: bytes) -> None: ...

ssh_accept_server_host_key_encoded = property(get_ssh_accept_server_host_key_encoded, set_ssh_accept_server_host_key_encoded)

Default Value

""

Remarks

The certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The ssh_accept_server_host_key_store and ssh_accept_server_host_key_subject properties also may be used to specify a certificate.

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

ssh_auth_mode Property

The authentication method to be used with the class when calling SSHLogon .

Syntax

def get_ssh_auth_mode() -> int: ...
def set_ssh_auth_mode(value: int) -> None: ...

ssh_auth_mode = property(get_ssh_auth_mode, set_ssh_auth_mode)

Default Value

2

Remarks

The Secure Shell (SSH) Authentication specification (RFC 4252) specifies multiple methods by which a user can be authenticated by an SSH server. When a call is made to ssh_logon, the class will connect to the SSH server and establish the security layer. After the connection has been secured, the client will send an authentication request to the ssh_host containing the ssh_user. The server will respond containing a list of methods by which that user may be authenticated.

The class will attempt to authenticate the user by one of those methods based on the value of ssh_auth_mode and other property values supplied by the user. Currently, the class supports the following authentication methods:

amNone (0)No authentication will be performed. The current ssh_user value is ignored, and the connection will be logged as anonymous.
amMultiFactor (1)This allows the class to attempt a multistep authentication process. The class will send authentication data to the server based on the list of methods allowed for the current user and the authentication property values supplied. The class will continue to send authentication data until the server acknowledges authentication success. If the server rejects an authentication step, the class fails with an error.
amPassword (2)The class will use the values of ssh_user and ssh_password to authenticate the user.
amPublicKey (3)The class will use the values of ssh_user and the ssh_cert* properties to authenticate the user. the ssh_cert* properties must have a private key available for this authentication method to succeed.
amKeyboardInteractive (4)At the time of authentication, the class will fire the on_ssh_keyboard_interactive event containing instructions on how to complete the authentication step.

Note: amKeyboardInteractive is not supported in SSHTunnel.

amGSSAPIWithMic (5)This allows the class to attempt Kerberos authentication using the GSSAPI-WITH-MIC scheme. The client will try Kerberos authentication using the value of ssh_user (single sign-on), or if ssh_password is specified as well, it will try Kerberos authentication with alternate credentials. This is currently supported only on Windows, unless using the Java edition, which also provides support for Linux and macOS.
amGSSAPIKeyex (6)This allows the class to attempt Kerberos authentication using the GSSAPIKeyex scheme. The client will try Kerberos authentication using the value of ssh_user (single sign-on), or if ssh_password is specified as well, it will try Kerberos authentication with alternate credentials. This is currently supported only on Windows, unless using the Java edition, which also provides support for Linux and macOS.
amCustom (99)This allows the class caller to take over the authentication process completely. When amCustom is set, the class will fire the on_ssh_custom_auth event as necessary to complete the authentication process.

Example 1. User/Password Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example 2. Public Key Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

ssh_cert_effective_date Property

The date on which this certificate becomes valid.

Syntax

def get_ssh_cert_effective_date() -> str: ...

ssh_cert_effective_date = property(get_ssh_cert_effective_date, None)

Default Value

""

Remarks

The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

This property is read-only.

ssh_cert_expiration_date Property

The date on which the certificate expires.

Syntax

def get_ssh_cert_expiration_date() -> str: ...

ssh_cert_expiration_date = property(get_ssh_cert_expiration_date, None)

Default Value

""

Remarks

The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

This property is read-only.

ssh_cert_extended_key_usage Property

A comma-delimited list of extended key usage identifiers.

Syntax

def get_ssh_cert_extended_key_usage() -> str: ...

ssh_cert_extended_key_usage = property(get_ssh_cert_extended_key_usage, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_fingerprint Property

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

Syntax

def get_ssh_cert_fingerprint() -> str: ...

ssh_cert_fingerprint = property(get_ssh_cert_fingerprint, None)

Default Value

""

Remarks

The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_cert_fingerprint_sha1 Property

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

Syntax

def get_ssh_cert_fingerprint_sha1() -> str: ...

ssh_cert_fingerprint_sha1 = property(get_ssh_cert_fingerprint_sha1, None)

Default Value

""

Remarks

The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_cert_fingerprint_sha256 Property

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

Syntax

def get_ssh_cert_fingerprint_sha256() -> str: ...

ssh_cert_fingerprint_sha256 = property(get_ssh_cert_fingerprint_sha256, None)

Default Value

""

Remarks

The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

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

This property is read-only.

ssh_cert_issuer Property

The issuer of the certificate.

Syntax

def get_ssh_cert_issuer() -> str: ...

ssh_cert_issuer = property(get_ssh_cert_issuer, None)

Default Value

""

Remarks

The issuer of the certificate. This property contains a string representation of the name of the issuing authority for the certificate.

This property is read-only.

ssh_cert_private_key Property

The private key of the certificate (if available).

Syntax

def get_ssh_cert_private_key() -> str: ...

ssh_cert_private_key = property(get_ssh_cert_private_key, None)

Default Value

""

Remarks

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

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

This property is read-only.

ssh_cert_private_key_available Property

Whether a PrivateKey is available for the selected certificate.

Syntax

def get_ssh_cert_private_key_available() -> bool: ...

ssh_cert_private_key_available = property(get_ssh_cert_private_key_available, None)

Default Value

FALSE

Remarks

Whether a ssh_cert_private_key is available for the selected certificate. If ssh_cert_private_key_available is True, the certificate may be used for authentication purposes (e.g., server authentication).

This property is read-only.

ssh_cert_private_key_container Property

The name of the PrivateKey container for the certificate (if available).

Syntax

def get_ssh_cert_private_key_container() -> str: ...

ssh_cert_private_key_container = property(get_ssh_cert_private_key_container, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_public_key Property

The public key of the certificate.

Syntax

def get_ssh_cert_public_key() -> str: ...

ssh_cert_public_key = property(get_ssh_cert_public_key, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_public_key_algorithm Property

The textual description of the certificate's public key algorithm.

Syntax

def get_ssh_cert_public_key_algorithm() -> str: ...

ssh_cert_public_key_algorithm = property(get_ssh_cert_public_key_algorithm, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_public_key_length Property

The length of the certificate's public key (in bits).

Syntax

def get_ssh_cert_public_key_length() -> int: ...

ssh_cert_public_key_length = property(get_ssh_cert_public_key_length, None)

Default Value

0

Remarks

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

This property is read-only.

ssh_cert_serial_number Property

The serial number of the certificate encoded as a string.

Syntax

def get_ssh_cert_serial_number() -> str: ...

ssh_cert_serial_number = property(get_ssh_cert_serial_number, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_signature_algorithm Property

The text description of the certificate's signature algorithm.

Syntax

def get_ssh_cert_signature_algorithm() -> str: ...

ssh_cert_signature_algorithm = property(get_ssh_cert_signature_algorithm, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_store Property

The name of the certificate store for the client certificate.

Syntax

def get_ssh_cert_store() -> bytes: ...
def set_ssh_cert_store(value: bytes) -> None: ...

ssh_cert_store = property(get_ssh_cert_store, set_ssh_cert_store)

Default Value

"MY"

Remarks

The name of the certificate store for the client certificate.

The ssh_cert_store_type property denotes the type of the certificate store specified by ssh_cert_store. If the store is password-protected, specify the password in ssh_cert_store_password.

ssh_cert_store is used in conjunction with the ssh_cert_subject property to specify client certificates. If ssh_cert_store has a value, and ssh_cert_subject or ssh_cert_encoded is set, a search for a certificate is initiated. Please see the ssh_cert_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:

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

When the certificate store type is cstPFXFile, this property must be set to the name of the file. When the type is cstPFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

ssh_cert_store_password Property

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

Syntax

def get_ssh_cert_store_password() -> str: ...
def set_ssh_cert_store_password(value: str) -> None: ...

ssh_cert_store_password = property(get_ssh_cert_store_password, set_ssh_cert_store_password)

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.

ssh_cert_store_type Property

The type of certificate store for this certificate.

Syntax

def get_ssh_cert_store_type() -> int: ...
def set_ssh_cert_store_type(value: int) -> None: ...

ssh_cert_store_type = property(get_ssh_cert_store_type, set_ssh_cert_store_type)

Default Value

0

Remarks

The type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class 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 class. The list_store_certificates method may be called after setting cert_store_type to cstPKCS11, cert_store_password to the PIN, and cert_store to the full path of the PKCS#11 DLL. The certificate information returned in the on_cert_list event's CertEncoded parameter may be saved for later use.

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

Code Example. SSH Authentication with Security Key: certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

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.

ssh_cert_subject_alt_names Property

Comma-separated lists of alternative subject names for the certificate.

Syntax

def get_ssh_cert_subject_alt_names() -> str: ...

ssh_cert_subject_alt_names = property(get_ssh_cert_subject_alt_names, None)

Default Value

""

Remarks

Comma-separated lists of alternative subject names for the certificate.

This property is read-only.

ssh_cert_thumbprint_md5 Property

The MD5 hash of the certificate.

Syntax

def get_ssh_cert_thumbprint_md5() -> str: ...

ssh_cert_thumbprint_md5 = property(get_ssh_cert_thumbprint_md5, None)

Default Value

""

Remarks

The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_cert_thumbprint_sha1 Property

The SHA-1 hash of the certificate.

Syntax

def get_ssh_cert_thumbprint_sha1() -> str: ...

ssh_cert_thumbprint_sha1 = property(get_ssh_cert_thumbprint_sha1, None)

Default Value

""

Remarks

The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_cert_thumbprint_sha256 Property

The SHA-256 hash of the certificate.

Syntax

def get_ssh_cert_thumbprint_sha256() -> str: ...

ssh_cert_thumbprint_sha256 = property(get_ssh_cert_thumbprint_sha256, None)

Default Value

""

Remarks

The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

ssh_cert_usage Property

The text description of UsageFlags .

Syntax

def get_ssh_cert_usage() -> str: ...

ssh_cert_usage = property(get_ssh_cert_usage, None)

Default Value

""

Remarks

The text description of ssh_cert_usage_flags.

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

  • Digital Signature
  • Non-Repudiation
  • Key Encipherment
  • Data Encipherment
  • Key Agreement
  • Certificate Signing
  • CRL Signing
  • Encipher Only

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

This property is read-only.

ssh_cert_usage_flags Property

The flags that show intended use for the certificate.

Syntax

def get_ssh_cert_usage_flags() -> int: ...

ssh_cert_usage_flags = property(get_ssh_cert_usage_flags, None)

Default Value

0

Remarks

The flags that show intended use for the certificate. The value of ssh_cert_usage_flags is a combination of the following flags:

0x80Digital Signature
0x40Non-Repudiation
0x20Key Encipherment
0x10Data Encipherment
0x08Key Agreement
0x04Certificate Signing
0x02CRL Signing
0x01Encipher Only

Please see the ssh_cert_usage property for a text representation of ssh_cert_usage_flags.

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

This property is read-only.

ssh_cert_version Property

The certificate's version number.

Syntax

def get_ssh_cert_version() -> str: ...

ssh_cert_version = property(get_ssh_cert_version, None)

Default Value

""

Remarks

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

This property is read-only.

ssh_cert_subject Property

The subject of the certificate used for client authentication.

Syntax

def get_ssh_cert_subject() -> str: ...
def set_ssh_cert_subject(value: str) -> None: ...

ssh_cert_subject = property(get_ssh_cert_subject, set_ssh_cert_subject)

Default Value

""

Remarks

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:

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

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

ssh_cert_encoded Property

The certificate (PEM/Base64 encoded).

Syntax

def get_ssh_cert_encoded() -> bytes: ...
def set_ssh_cert_encoded(value: bytes) -> None: ...

ssh_cert_encoded = property(get_ssh_cert_encoded, set_ssh_cert_encoded)

Default Value

""

Remarks

The certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The ssh_cert_store and ssh_cert_subject properties also may be used to specify a certificate.

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

ssh_compression_algorithms Property

The comma-separated list containing all allowable compression algorithms.

Syntax

def get_ssh_compression_algorithms() -> str: ...
def set_ssh_compression_algorithms(value: str) -> None: ...

ssh_compression_algorithms = property(get_ssh_compression_algorithms, set_ssh_compression_algorithms)

Default Value

"none,zlib"

Remarks

During the Secure Shell (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. Therefore, it is important to list multiple algorithms in preferential order. If no algorithm can be agreed on, the class 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 class:

  • zlib
  • zlib@openssh.com
  • none

ssh_encryption_algorithms Property

The comma-separated list containing all allowable encryption algorithms.

Syntax

def get_ssh_encryption_algorithms() -> str: ...
def set_ssh_encryption_algorithms(value: str) -> None: ...

ssh_encryption_algorithms = property(get_ssh_encryption_algorithms, set_ssh_encryption_algorithms)

Default Value

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

Remarks

During the Secure Shell (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. Therefore, it is important to list multiple algorithms in preferential order. If no algorithm can be agreed on, the class 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 class:

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

ssh_host Property

The address of the Secure Shell (SSH) host.

Syntax

def get_ssh_host() -> str: ...
def set_ssh_host(value: str) -> None: ...

ssh_host = property(get_ssh_host, set_ssh_host)

Default Value

""

Remarks

The ssh_host property specifies the IP address (IP number in dotted internet format) or domain name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If the ssh_host property is set to a domain name, a DNS request is initiated, and upon successful termination of the request, the ssh_host property is set to the corresponding address. If the search is not successful, an error is returned.

The ssh_host must be the same host that will be assumed for SSH as for the remote service being connected to.

ssh_password Property

The password for Secure Shell (SSH) password-based authentication.

Syntax

def get_ssh_password() -> str: ...
def set_ssh_password(value: str) -> None: ...

ssh_password = property(get_ssh_password, set_ssh_password)

Default Value

""

Remarks

ssh_password specifies the password that is used to authenticate the client to the SSH server.

ssh_port Property

The port on the Secure Shell (SSH) server where the SSH service is running; by default, 22.

Syntax

def get_ssh_port() -> int: ...
def set_ssh_port(value: int) -> None: ...

ssh_port = property(get_ssh_port, set_ssh_port)

Default Value

22

Remarks

The ssh_port specifies a service port on the SSH host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

ssh_user Property

The username for Secure Shell (SSH) authentication.

Syntax

def get_ssh_user() -> str: ...
def set_ssh_user(value: str) -> None: ...

ssh_user = property(get_ssh_user, set_ssh_user)

Default Value

""

Remarks

ssh_user specifies the username that is used to authenticate the client to the SSH server. This property is required.

Example 1. User/Password Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example 2. Public Key Authentication: Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

timeout Property

This property includes the timeout for the class.

Syntax

def get_timeout() -> int: ...
def set_timeout(value: int) -> None: ...

timeout = property(get_timeout, set_timeout)

Default Value

60

Remarks

If the timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of timeout seconds.

The class will use do_events 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 class fails with an error.

Note: By default, all timeouts are inactivity timeouts, that is, 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 60 seconds.

cancel_forwarding Method

Requests the server to stop forwarding a remote Transmission Control Protocol (TCP)/IP port.

Syntax

def cancel_forwarding(address: str, port: int) -> None: ...

Remarks

The cancel_forwarding cancels a previous TCP/IP port forwarding request. When calling it, provide the same argument values you provided on the request_forwarding call.

close_channel Method

Closes a existing SSHChannel .

Syntax

def close_channel(channel_id: str) -> None: ...

Remarks

ChannelId is the identifier for the Secure Shell (SSH) channel to be closed.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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.

decode_packet Method

Decodes a hex-encoded Secure Shell (SSH) packet.

Syntax

def decode_packet(encoded_packet: str) -> bytes: ...

Remarks

This method is used to decode an SSH packet created by encode_packet.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the on_ssh_custom_auth event.

do_events Method

This method processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

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

encode_packet Method

Hex encodes a Secure Shell (SSH) packet.

Syntax

def encode_packet(packet: bytes) -> str: ...

Remarks

This method is used to encode a raw SSH packet created by set_ssh_param.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the on_ssh_custom_auth event.

exchange_keys Method

Causes the class to exchange a new set of session keys with the SSHHost .

Syntax

def exchange_keys() -> None: ...

Remarks

Secure Shell (SSH) key renegotiation can be initiated by either end of an established SSH connection. exchange_keys allows the user to start such a renegotiation with the ssh_host. During this process, on_ssh_status 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. Doing so makes it more difficult to break the security of data-intensive or long-lived connections.

get_ssh_param Method

Reads a field from a Secure Shell (SSH) packet's payload.

Syntax

def get_ssh_param(payload: bytes, field: str) -> str: ...

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 on_ssh_channel_request. 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 requested.
WantsReply (boolean)Whether or not the client wants a reply to the request.

The remaining fields that are available in the payload are dependent on 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 (e.g., "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 (e.g., "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 (e.g., "sftp").

xon-xoff

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 set_ssh_param. 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 set_ssh_param.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the on_ssh_custom_auth event.

get_ssh_param_bytes Method

Reads a field from a Secure Shell (SSH) packet's payload.

Syntax

def get_ssh_param_bytes(payload: bytes, field: str) -> bytes: ...

Remarks

This method is the same as calling get_ssh_param, but it returns raw bytes instead of strings.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the on_ssh_custom_auth event.

request_forwarding Method

Requests the server to forward a remote Transmission Control Protocol (TCP)/IP port.

Syntax

def request_forwarding(address: str, port: int, forwarding_host: str, forwarding_port: int) -> None: ...

Remarks

The request_forwarding method asks the server to listen at the specified TCP/IP Address and Port for connection requests and then forward them as new Secure Shell (SSH) channels to the class.

ForwardingHost and ForwardingPort may be used to specify an address and port to which traffic will automatically be forwarded. If automatic forwarding is not desired, specify an empty string ("") for the ForwardingHost parameter.

The Address argument can be specified in different ways:

  • "" means that connections are to be accepted on all protocol families supported by the server.
  • "0.0.0.0" means to listen on all IPv4 addresses.
  • "::" means to listen on all IPv6 addresses.
  • "localhost" means to listen on all protocol families supported by the Secure Shell (SSH) implementation on loopback addresses only.
  • "127.0.0.1" and "::1" indicate listening on the loopback interfaces for IPv4 and IPv6, respectively.

Passing a value of 0 for the Port parameter instructs the server to assign a port. In this case, query the ForwardedPort setting to determine the port that was assigned by the server.

The class has two modes that allow data to be dealt with directly from the events, or automatically forwarded on to a different endpoint.

Event Based Operation

In this mode, any data received by the class over the tunnel causes the events of the class to fire. For instance:

SSHReverseTunnel.RequestForwarding("0.0.0.0", 777, "", 0);

In the above code, forwarding is requested from port 777 on the ssh_host. Any data received on port 777 by the ssh_host will be sent to the class. In the above code, the last two parameters are empty and 0, indicating to the class that no local forwarding is requested.

Once request_forwarding returns, the Secure Shell (SSH) reverse tunnel is established. Any connection made to the SSH host on the specified port will then trigger the class's events to fire, allowing you to handle the connection request and data.

When a client connects to the SSH host on the specified port, the on_ssh_channel_open_request event will fire. Within this event, choose to accept or reject the connection by setting the Accept parameter. This event contains details about the connection that may be used when determining whether to accept the connection.

After the channel is established, data are received through the on_ssh_channel_data event. Call the send_channel_data method to send data over the channel, and call the close_channel method to close the channel.

Local Forwarding

In this mode, any data received by the class is automatically forwarded to a separate endpoint. This allows the class to act as a sort of proxy. There is no need to handle data directly in this case. For instance: SSHReverseTunnel.RequestForwarding("0.0.0.0", 777, "nsoftware.com", 80);

In the above code, forwarding is requested from port 777 on ssh_host. The class is instructed to establish a connection to "nsoftware.com" on port 80 when a client connects to ssh_host on port 777. Any data received from the client connected to ssh_host on port 777 will automatically be forwarded to "nsoftware.com" on port 80. Any data received back from "nsoftware.com" on port 80 will be sent back to the connected client.

In this mode, data may flow freely from the client connected to the ssh_host to the endpoint specified in the request_forwarding method without any additional code required.

reset Method

This method will reset the class.

Syntax

def reset() -> None: ...

Remarks

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

send_channel_data Method

Sends data over a Secure Shell (SSH) channel.

Syntax

def send_channel_data(channel_id: str, data: bytes) -> None: ...

Remarks

This method can be used to send arbitrary data to the channel with the specified ChannelId.

set_ssh_param Method

Writes a field to the end of a payload.

Syntax

def set_ssh_param(payload: bytes, field_type: str, field_value: str) -> bytes: ...

Remarks

This method is used to build the payload portion of a Secure Shell (SSH) packet to be sent later by a call to send_ssh_packet. Payload should contain the result of a previous call to set_ssh_param. 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:

sA plaintext string containing the default system encoding of the data.
sbA string containing the hex-encoded data (e.g., "A1B23C")
mA variable-length large integer, encoded as a textual representation of the value (e.g., "1234").
iA 32-bit integer, encoded as a textual representation of the value (e.g., "1234").
lA 64-bit integer, encoded as a textual representation of the value (e.g., "1234").
bA single byte, encoded as a textual representation of the value (e.g., "123").
fA boolean flag, encoded as a textual representation of the value (e.g., 'True' or 'False')

Note: Integer values may be hexadecimal encoded by prefixing "0x" to the beginning of the string; otherwise, the value is assumed to be Base10.

Note: This method is applicable only for reading and creating Secure Shell (SSH) packets for use within the on_ssh_custom_auth event.

ssh_logoff Method

Logs off from the Secure Shell (SSH) server.

Syntax

def ssh_logoff() -> None: ...

Remarks

Logs off from the SSH server. If that fails, the connection is terminated by the local host.

ssh_logon Method

Logs on to the SSHHost using the current SSHUser and SSHPassword .

Syntax

def ssh_logon(ssh_host: str, ssh_port: int) -> None: ...

Remarks

Logs on to the Secure Shell (SSH) server using the current ssh_user and ssh_password. This will perform the SSH handshake and authentication.

Example. Logging On:

SSHClient.SSHUser = "username" SSHClient.SSHPassword = "password" SSHClient.SSHLogon("sshHost", sshPort)

on_connected Event

Fired immediately after a connection completes (or fails).

Syntax

class SSHReverseTunnelConnectedEventParams(object):
  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class SSHReverseTunnel:
@property
def on_connected() -> Callable[[SSHReverseTunnelConnectedEventParams], None]: ...
@on_connected.setter
def on_connected(event_hook: Callable[[SSHReverseTunnelConnectedEventParams], None]) -> None: ...

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 Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Please refer to the Error Codes section for more information.

on_connection_status Event

Fired to indicate changes in the connection state.

Syntax

class SSHReverseTunnelConnectionStatusEventParams(object):
  @property
  def connection_event() -> str: ...

  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class SSHReverseTunnel:
@property
def on_connection_status() -> Callable[[SSHReverseTunnelConnectionStatusEventParams], None]: ...
@on_connection_status.setter
def on_connection_status(event_hook: Callable[[SSHReverseTunnelConnectionStatusEventParams], None]) -> None: ...

Remarks

This event is fired when the connection state changes: for example, completion of a firewall or proxy connection or completion of a security handshake.

The ConnectionEvent parameter indicates the type of connection event. Values may include the following:

Firewall connection complete.
Secure Sockets Layer (SSL) or S/Shell handshake complete (where applicable).
Remote host connection complete.
Remote host disconnected.
SSL or S/Shell connection broken.
Firewall host disconnected.
StatusCode has the error code returned by the Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

on_disconnected Event

Fired when a connection is closed.

Syntax

class SSHReverseTunnelDisconnectedEventParams(object):
  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class SSHReverseTunnel:
@property
def on_disconnected() -> Callable[[SSHReverseTunnelDisconnectedEventParams], None]: ...
@on_disconnected.setter
def on_disconnected(event_hook: Callable[[SSHReverseTunnelDisconnectedEventParams], None]) -> None: ...

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 Transmission Control Protocol (TCP/IP) subsystem. Description contains a description of this code. The value of StatusCode is equal to the value of the TCP/IP error.

Please refer to the Error Codes section for more information.

on_error Event

Fired when information is available about errors during data delivery.

Syntax

class SSHReverseTunnelErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class SSHReverseTunnel:
@property
def on_error() -> Callable[[SSHReverseTunnelErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[SSHReverseTunnelErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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

on_log Event

Fired once for each log message.

Syntax

class SSHReverseTunnelLogEventParams(object):
  @property
  def log_level() -> int: ...

  @property
  def message() -> str: ...

  @property
  def log_type() -> str: ...

# In class SSHReverseTunnel:
@property
def on_log() -> Callable[[SSHReverseTunnelLogEventParams], None]: ...
@on_log.setter
def on_log(event_hook: Callable[[SSHReverseTunnelLogEventParams], None]) -> None: ...

Remarks

Fired once for each log message generated by the class. The verbosity is controlled by the LogLevel setting.

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

0 (None) No messages are logged.
1 (Info - Default) Informational events such as Secure Shell (SSH) handshake messages are logged.
2 (Verbose) Detailed data such as individual packet information are 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.

on_reconnect_attempt Event

Fired when attempting to reconnect.

Syntax

class SSHReverseTunnelReconnectAttemptEventParams(object):
  @property
  def host() -> str: ...

  @property
  def port() -> int: ...

  @property
  def retry_count() -> int: ...

  @property
  def retries_remaining() -> int: ...

  @property
  def max_retry_count() -> int: ...

  @property
  def retry_interval() -> int: ...

  @property
  def retry_type() -> int: ...

  @property
  def remote_listening_port() -> int: ...

  @property
  def cancel() -> bool: ...
  @cancel.setter
  def cancel(value) -> None: ...

# In class SSHReverseTunnel:
@property
def on_reconnect_attempt() -> Callable[[SSHReverseTunnelReconnectAttemptEventParams], None]: ...
@on_reconnect_attempt.setter
def on_reconnect_attempt(event_hook: Callable[[SSHReverseTunnelReconnectAttemptEventParams], None]) -> None: ...

Remarks

This event fires both when attempting to reconnect to the ssh_host and when reestablishing a Secure Shell (SSH) tunnel.

This is applicable only when AutoReconnect is enabled. To determine which type of connection is being established check the RetryType parameter.

The following table provides details about the parameters:

Host The SSH host to which the connection is attempted.
Port The port on the SSH host to which the connection is attempted.
RetryCount The current retry attempt. For instance, this may be attempt number 2 out of 5, then RetryCount will hold the value 2.
RetriesRemaining The number of retries remaining after this attempt. This number does not include the current attempt. If MaxRetryCount is set to unlimited, this will return -1.
MaxRetryCount The maximum number of retries as specified in MaxRetryCount.
RetryInterval The interval (in seconds) between retry attempts as specified in RetryInterval.
RetryType The type of connection being retried. Possible values are as follows:
  • 0 - SSH
  • 1 - Tunnel
RemoteListeningPort The port on the SSH host that the reverse tunnel will use. This is applicable only when RetryType is 1.
Cancel Maybe set within this event to cancel the retry attempts. If set to True, no further retry attempts will be executed.

on_ssh_channel_closed Event

Fired when a channel is closed.

Syntax

class SSHReverseTunnelSSHChannelClosedEventParams(object):
  @property
  def channel_id() -> str: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_closed() -> Callable[[SSHReverseTunnelSSHChannelClosedEventParams], None]: ...
@on_ssh_channel_closed.setter
def on_ssh_channel_closed(event_hook: Callable[[SSHReverseTunnelSSHChannelClosedEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_closed event is fired when a channel is closed on a Secure Shell (SSH) connection.

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

on_ssh_channel_data Event

Fired when the SSHHost sends channel data to the client.

Syntax

class SSHReverseTunnelSSHChannelDataEventParams(object):
  @property
  def channel_id() -> str: ...

  @property
  def channel_data() -> bytes: ...

  @property
  def channel_data_eol_found() -> bool: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_data() -> Callable[[SSHReverseTunnelSSHChannelDataEventParams], None]: ...
@on_ssh_channel_data.setter
def on_ssh_channel_data(event_hook: Callable[[SSHReverseTunnelSSHChannelDataEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_data event will fire as data are received for the given ChannelId. ChannelData will contain the decrypted contents of the Secure Shell (SSH) packet.

ChannelDataEOLFound indicates whether or not the ChannelEOL string for the channel was found at the end of ChannelData. If the ChannelEOL string was found, then ChannelDataEOLFound is True.

If ChannelData is part of a data portion of a length that is larger than the MaxChannelLength for the Channel with no ChannelEOL strings in it, then ChannelDataEOLFound is False.

Note: This means that one of more on_ssh_channel_data events with ChannelDataEOLFound set to False can be received.

If the ChannelEOL property for the Channel is "" (empty string), then ChannelDataEOLFound can be disregarded (it is always True).

on_ssh_channel_eof Event

Fired when the remote peer signals the end of the data stream for the channel.

Syntax

class SSHReverseTunnelSSHChannelEOFEventParams(object):
  @property
  def channel_id() -> str: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_eof() -> Callable[[SSHReverseTunnelSSHChannelEOFEventParams], None]: ...
@on_ssh_channel_eof.setter
def on_ssh_channel_eof(event_hook: Callable[[SSHReverseTunnelSSHChannelEOFEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_eof event is fired when the end of the data stream for a channel on a Secure Shell (SSH) connection is reached.

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

on_ssh_channel_opened Event

Fired when a channel is successfully opened.

Syntax

class SSHReverseTunnelSSHChannelOpenedEventParams(object):
  @property
  def channel_id() -> str: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_opened() -> Callable[[SSHReverseTunnelSSHChannelOpenedEventParams], None]: ...
@on_ssh_channel_opened.setter
def on_ssh_channel_opened(event_hook: Callable[[SSHReverseTunnelSSHChannelOpenedEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_opened event is fired when a channel is successfully opened on a Secure Shell (SSH) connection.

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

on_ssh_channel_open_request Event

Fired when the peer attempts to open a new channel.

Syntax

class SSHReverseTunnelSSHChannelOpenRequestEventParams(object):
  @property
  def channel_id() -> str: ...

  @property
  def service() -> str: ...

  @property
  def connected_address() -> str: ...

  @property
  def connected_port() -> int: ...

  @property
  def origin_address() -> str: ...

  @property
  def origin_port() -> int: ...

  @property
  def accept() -> bool: ...
  @accept.setter
  def accept(value) -> None: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_open_request() -> Callable[[SSHReverseTunnelSSHChannelOpenRequestEventParams], None]: ...
@on_ssh_channel_open_request.setter
def on_ssh_channel_open_request(event_hook: Callable[[SSHReverseTunnelSSHChannelOpenRequestEventParams], None]) -> None: ...

Remarks

This event is fired whenever a peer 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. Usually, this will be "forwarded-tcpip", in which case ConnectedAddress and ConnectedPort will contain the remote Transmission Control Protocol (TCP)/IP address and port on the peer to which the connection was established; OriginAddress and OriginPort contain the originating TCP/IP address and port of the connection.

By default, Accept is True and the channel will be opened. Set Accept to False to reject the request.

on_ssh_channel_ready_to_send Event

Fired when the class is ready to send data.

Syntax

class SSHReverseTunnelSSHChannelReadyToSendEventParams(object):
  @property
  def channel_id() -> str: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_ready_to_send() -> Callable[[SSHReverseTunnelSSHChannelReadyToSendEventParams], None]: ...
@on_ssh_channel_ready_to_send.setter
def on_ssh_channel_ready_to_send(event_hook: Callable[[SSHReverseTunnelSSHChannelReadyToSendEventParams], None]) -> None: ...

Remarks

This event fires when data can be sent over the Secure Shell (SSH) Channel specified by ChannelId.

When a channel is opened, this event will fire after 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 on_ssh_channel_ready_to_send or ready_to_send to determine when data can be sent again.

When timeout is set to a positive value, the class will block when sending data until the data can be successfully sent and on_ssh_channel_ready_to_send and ready_to_send do not need to be monitored.

on_ssh_channel_request Event

Fired when the SSHHost sends a channel request to the client.

Syntax

class SSHReverseTunnelSSHChannelRequestEventParams(object):
  @property
  def channel_id() -> str: ...

  @property
  def request_type() -> str: ...

  @property
  def packet() -> bytes: ...

  @property
  def success() -> bool: ...
  @success.setter
  def success(value) -> None: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_request() -> Callable[[SSHReverseTunnelSSHChannelRequestEventParams], None]: ...
@on_ssh_channel_request.setter
def on_ssh_channel_request(event_hook: Callable[[SSHReverseTunnelSSHChannelRequestEventParams], None]) -> None: ...

Remarks

The ssh_host may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the class. Others, however, may need the attention of the user to be dealt with properly within the scope of the application.

ChannelId identifies the channel receiving the request.

Type will contain the type of the request. These types depend on 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 Secure Shell (SSH) packet. If the request type has specific parameters, they can be parsed out of this data.

Success should be used to instruct the class to respond to the request with either a success or failure notification. If the request is successful, on_ssh_channel_requested 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 Secure Shell (SSH) data until the event returns. To prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_requested Event

Fired if the SSHChannelRequest was successful; any further processing for the channel request should be done here.

Syntax

class SSHReverseTunnelSSHChannelRequestedEventParams(object):
  @property
  def channel_id() -> str: ...

  @property
  def request_type() -> str: ...

  @property
  def packet() -> bytes: ...

# In class SSHReverseTunnel:
@property
def on_ssh_channel_requested() -> Callable[[SSHReverseTunnelSSHChannelRequestedEventParams], None]: ...
@on_ssh_channel_requested.setter
def on_ssh_channel_requested(event_hook: Callable[[SSHReverseTunnelSSHChannelRequestedEventParams], None]) -> None: ...

Remarks

The ssh_host may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the class. Others, however, may need the attention of the user to be dealt with properly within the scope of the application.

ChannelId identifies the channel receiving the request.

Type will contain the type of the request. These types depend on 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 Secure Shell (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 Secure Shell (SSH) data until the event returns. To prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_custom_auth Event

Fired when the class is doing a custom authentication.

Syntax

class SSHReverseTunnelSSHCustomAuthEventParams(object):
  @property
  def packet() -> str: ...
  @packet.setter
  def packet(value) -> None: ...

# In class SSHReverseTunnel:
@property
def on_ssh_custom_auth() -> Callable[[SSHReverseTunnelSSHCustomAuthEventParams], None]: ...
@on_ssh_custom_auth.setter
def on_ssh_custom_auth(event_hook: Callable[[SSHReverseTunnelSSHCustomAuthEventParams], None]) -> None: ...

Remarks

on_ssh_custom_auth is fired during the user authentication stage of the Secure Shell (SSH) logon process if ssh_auth_mode is set to amCustom. Packet contains the last raw SSH packet sent by the server, in HEX-encoded format.

The client should create a new raw SSH packet to send to the server and set Packet to the HEX-encoded representation of the packet to send.

In all cases, Packet will start with the message type field.

To read the incoming packet, call decode_packet and then use the get_ssh_param and get_ssh_param_bytes methods. To create a packet, use the set_ssh_param method and then call encode_packet to obtain a HEX-encoded value and assign this to the Packet parameter.

on_ssh_keyboard_interactive Event

Fired when the class receives a request for user input from the server.

Syntax

class SSHReverseTunnelSSHKeyboardInteractiveEventParams(object):
  @property
  def name() -> str: ...

  @property
  def instructions() -> str: ...

  @property
  def prompt() -> str: ...

  @property
  def response() -> str: ...
  @response.setter
  def response(value) -> None: ...

  @property
  def echo_response() -> bool: ...

# In class SSHReverseTunnel:
@property
def on_ssh_keyboard_interactive() -> Callable[[SSHReverseTunnelSSHKeyboardInteractiveEventParams], None]: ...
@on_ssh_keyboard_interactive.setter
def on_ssh_keyboard_interactive(event_hook: Callable[[SSHReverseTunnelSSHKeyboardInteractiveEventParams], None]) -> None: ...

Remarks

on_ssh_keyboard_interactive is fired during the user authentication stage of the Secure Shell (SSH) logon process. During authentication, the class will request a list of available authentication methods for the ssh_user. For example, if the ssh_host responds with "keyboard-interactive", the class will fire this event to allow the client application to set the password.

During authentication, the SSH server may respond with a request for the user's authentication information. Name is a server-provided value associated with the authentication method such as "CRYPTOCard Authentication". Instructions will contain specific instructions, also supplied by the server, for how the user should respond.

Along with these values, the server will also send at least one input Prompt to be displayed to and filled out by the user. Response should be set to the user's input, and will be sent back in the user authentication information response. EchoResponse is a server recommendation for whether or not the user's response should be echoed back during input.

Note: The server may send several prompts in a single packet. The class will fire the on_ssh_keyboard_interactive event once for each prompt.

on_ssh_server_authentication Event

Fired after the server presents its public key to the client.

Syntax

class SSHReverseTunnelSSHServerAuthenticationEventParams(object):
  @property
  def host_key() -> bytes: ...

  @property
  def fingerprint() -> str: ...

  @property
  def key_algorithm() -> str: ...

  @property
  def cert_subject() -> str: ...

  @property
  def cert_issuer() -> str: ...

  @property
  def status() -> str: ...

  @property
  def accept() -> bool: ...
  @accept.setter
  def accept(value) -> None: ...

# In class SSHReverseTunnel:
@property
def on_ssh_server_authentication() -> Callable[[SSHReverseTunnelSSHServerAuthenticationEventParams], None]: ...
@on_ssh_server_authentication.setter
def on_ssh_server_authentication(event_hook: Callable[[SSHReverseTunnelSSHServerAuthenticationEventParams], None]) -> None: ...

Remarks

This event is fired when the client can decide whether or not to continue with the connection process. If the public key is known to be a valid key for the Secure Shell (SSH) server, Accept should be set to True within the event. Otherwise, the server will not be authenticated and the connection will be broken.

Accept will be True only if either HostKey or Fingerprint is identical to the value of ssh_accept_server_host_key.

Accept may be set to True manually to accept the server host key.

Note: SSH's security inherently relies on client verification of the host key. Ignoring the host key and always setting Accept to True is strongly discouraged, and could cause potentially serious security vulnerabilities in your application. It is recommended that clients maintain a list of known keys for each server and check HostKey against this list each time a connection is attempted.

Host Key contains the full binary text of the key, in the same format used internally by SSH.

Fingerprint holds the SHA-256 hash of HostKey in the hex-encoded form: 0a:1b:2c:3d. To configure the hash algorithm used to calculate this value, see SSHFingerprintHashAlgorithm.

KeyAlgorithm identifies the host key algorithm. The following values are supported:

  • ssh-rsa
  • ssh-dss
  • rsa-sha2-256
  • rsa-sha2-512
  • x509v3-sign-rsa
  • x509v3-sign-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
To limit the accepted host key algorithms, refer to SSHPublicKeyAlgorithms.

CertSubject is the subject of the certificate. This is applicable only when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

CertIssuer is the issuer of the certificate. This is applicable only when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

Status is reserved for future use.

on_ssh_status Event

Fired to track the progress of the secure connection.

Syntax

class SSHReverseTunnelSSHStatusEventParams(object):
  @property
  def message() -> str: ...

# In class SSHReverseTunnel:
@property
def on_ssh_status() -> Callable[[SSHReverseTunnelSSHStatusEventParams], None]: ...
@on_ssh_status.setter
def on_ssh_status(event_hook: Callable[[SSHReverseTunnelSSHStatusEventParams], None]) -> None: ...

Remarks

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

SSHReverseTunnel Config Settings

The class 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 class, access to these internal properties is provided through the config method.

SSHReverseTunnel Config Settings

AutoReconnect:   Whether to automatically reconnect.

This configuration setting controls automatic recovery of the Secure Shell (SSH) connection. If logon is disrupted or the channel is closed, the component can be configured to attempt reconnection automatically. Possible values follow:

ValueDescription
0 (None) Do not automatically reconnect.
1 (Default) Reconnect if an existing connection is broken.
2 (Always) Retry the initial logon as well as recover an existing connection.

See MaxRetryCount and RetryInterval for additional related settings.

DefaultChannelIdleTimeout:   The inactivity timeout for channels.

This configuration setting specifies the idle timeout in seconds for each connected channel. If there is no activity on the channel for the specified timeout the channel is closed and the client is disconnected.

The default value is 0, which is treated as an infinite timeout (the channel is never closed because of inactivity).

ForwardedPort:   The remote port which is forwarded.

When calling request_forwarding with a value of 0 for the port parameter, the server will assign the port automatically. This configuration setting may be queried to determine the port that was assigned by the server.

ForwardingLocalHost:   The interface on which to bind when forwarding data.

When the class is configured to automatically forward data to a destination, this configuration setting may be used to specify the interface to which the class binds when establishing the connection to the forwarding host.

This may be set to an IP address in the form aaa.bbb.ccc.ddd. By default this is unspecified and the system will automatically select the interface.

MaxRetryCount:   The maximum number of retries when reconnecting.

This configuration setting defines the maximum number of connection attempts performed when reestablishing a broken connection. This configuration setting applies only when AutoReconnect is enabled. By default, the component will reconnect forever.

RetryInterval:   The interval in seconds between reconnect attempts.

This configuration setting specifies the number of seconds between reconnection attempts. This setting applies only when AutoReconnect is enabled. The default value is 5.

SSHClient Config Settings

ChannelDataEOL[ChannelId]:   Used to break the incoming data stream into chunks.

By default MaxChannelDataLength is 0 and ChannelDataEOL is an empty string. on_ssh_channel_data fires whenever an SSH_MSG_CHANNEL_DATA packet is received.

If MaxChannelDataLength is greater than 0 and ChannelDataEOL is a nonempty string, the class will internally buffer data waiting to fire on_ssh_channel_data until either MaxChannelDataLength is reached or ChannelDataEOL is found, whichever comes first. Query ChannelDataEOLFound to know which condition was met. The buffer is reset any time on_ssh_channel_data fires.

ChannelDataEOL and MaxChannelDataLength must be set together or unexpected behavior could occur.

ChannelDataEOLFound[ChannelId]:   Determines if ChannelDataEOL was found.

If True,then ChannelDataEOL was found. If False, then MaxChannelDataLength was reached.

This configuration setting is valid only when queried inside on_ssh_channel_data, MaxChannelDataLength > 0, and ChannelDataEOL is nonempty.

ClientSSHVersionString:   The SSH version string used by the class.

This configuration setting specifies the Secure Shell (SSH) version string used by the class. The default value is "SSH-2.0-IPWorks SSH Client 2024".

Most SSH servers expect the SSH version string to have the expected format "SSH-protocol version-software version". See above for an example.

DoNotRepeatAuthMethods:   Whether the class will repeat authentication methods during multifactor authentication.

The default value is True. When set to False, the class will repeat authentication methods that have already been completed during multifactor authentication.

EnablePageantAuth:   Whether to use a key stored in Pageant to perform client authentication.

This configuration setting controls whether Pageant authentication is disabled, enabled, or required. When enabled or required, the class attempts to communicate with PuTTY's ssh-agent, called "Pageant", over shared memory to perform public key authentication. Possible values and the corresponding behavior is described as follows:

ValueDescription
0 (Disabled - default) No communication with Pageant is attempted.
1 (Enabled) Pageant authentication is used if available. If Pageant is not running, or does not contain the expected key, no error is thrown.
2 (Required) Only Pageant authentication is used. If Pageant is not running, or does not contain the expected key, an error is thrown.

Example 1. Enabling Pageant: component.Config("EnablePageantAuth=1"); component.SSHUser = "sshuser"; component.SSHLogon("localhost", 22);

Note: This functionality is available only on Windows.

KerberosDelegation:   If true, asks for credentials with delegation enabled during authentication.

The default value is "True". If set to "False", the client will not ask for credentials delegation support during authentication.

Note: Even if the client asks for delegation, the server/KDC might not grant it, and authentication will still succeed.

KerberosRealm:   The fully qualified domain name of the Kerberos Realm to use for GSSAPI authentication.

This property may be set to the fully qualified (DNS) name of the kerberos realm (or Windows Active Directory domain name) to use during GSSAPI authentication. This can be used to force authentication with a given realm if the client and server machines are not part of the same domain.

KerberosSPN:   The Kerberos Service Principal Name of the SSH host.

This property can be set to specify the Service Principal Name (SPN) associated with the SSH service on the remote host. This will usually be in the form "host/fqdn.of.sshhost[@REALM]". If not specified, the class will assume the SPN is based on the value of the ssh_host property and the kerberos realm used for authentication.

KeyRenegotiationThreshold:   Sets the threshold for the SSH Key Renegotiation.

This property allows you to specify the threshold, in the number of bytes, for the Secure Shell (SSH) key renegotiation. The default value for this property is set to 1 GB.

Example. Setting the Threshold to 500 MB: SSHComponent.Config("KeyRenegotiationThreshold=524288000")

LogLevel:   Specifies the level of detail that is logged.

This configuration setting controls the level of detail that is logged through the on_log event. Possible values are as follows:

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

MaxChannelDataLength[ChannelId]:   The maximum amount of data to accumulate when no ChannelDataEOL is found.

By default MaxChannelDataLength is 0 and ChannelDataEOL is an empty string. on_ssh_channel_data fires whenever an SSH_MSG_CHANNEL_DATA packet is received.

If MaxChannelDataLength is greater than 0 and ChannelDataEOL is a nonempty string, the class will internally buffer data waiting to fire on_ssh_channel_data until either MaxChannelDataLength is reached or ChannelDataEOL is found, whichever comes first. Query ChannelDataEOLFound to know which condition was met. The buffer is reset any time on_ssh_channel_data fires.

ChannelDataEOL and MaxChannelDataLength must be set together or unexpected behavior could occur.

MaxPacketSize:   The maximum packet size of the channel, in bytes.

This configuration setting specifies the maximum size of an individual data packet, in bytes, that can be sent to the sender.

MaxWindowSize:   The maximum window size allowed for the channel, in bytes.

This configuration setting specifies how many bytes of channel data can be sent to the sender of this message without adjusting the window.

Note: This value may be changed during the connection, but the window size can only be increased, not decreased.

NegotiatedStrictKex:   Returns whether strict key exchange was negotiated to be used.

This configuration setting specifies whether strict key exchange (strict kex) was negotiated during the SSH handshake. 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")

PasswordPrompt:   The text of the password prompt used in keyboard-interactive authentication.

This configuration setting optionally specifies a pattern to be matched to the prompt received from the server during keyboard-interactive authentication. If a matching prompt is detected the class automatically responds to the prompt with the password specified by ssh_password.

This provides an easy way to automatically reply to prompts with the password if one is presented by the server. The password will be autofilled in the Response parameter of the on_ssh_keyboard_interactive event in the case of a match.

The following special characters are supported for pattern matching:

? Any single character.
* Any characters or no characters (e.g., C*t matches Cat, Cot, Coast, Ct).
[,-] A range of characters (e.g., [a-z], [a], [0-9], [0-9,a-d,f,r-z]).
\ The slash is ignored and exact matching is performed on the next character.

If these characters need to be used as a literal in a pattern, then they must be escaped by surrounding them with brackets []. Note: "]" and "-" do not need to be escaped. See below for the escape sequences:

CharacterEscape Sequence
? [?]
* [*]
[ [[]
\ [\]

For example, to match the value [Something].txt, specify the pattern [[]Something].txt.

PreferredDHGroupBits:   The size (in bits) of the preferred modulus (p) to request from the server.

This configuration setting may be when using the diffie-hellman-group-exchange-sha1 or diffie-hellman-group-exchange-sha256 key exchange algorithms to control the preferred size, in bits, of the modulus (p) prime number to request from the server. Acceptable values are between 1024 and 8192.

RecordLength:   The length of received data records.

If set to a positive value, this configuration setting defines the length of data records to be received. The class will accumulate data until RecordLength is reached and only then will it fire the on_data_in 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 on_data_in event.

The default value is 0, meaning this setting is not used.

ServerSSHVersionString:   The remote host's SSH version string.

This configuration setting will return the remote host's SSH version string, which can help when identifying problematic servers. This configuration setting is read-only.

SignedSSHCert:   The CA signed client public key used when authenticating.

When authenticating via public key authentication, this setting may be set to the certificate authority (CA) signed client's public key. This is useful when the server has been configured to trust client keys signed by a particular CA. For instance: component.Config("SignedSSHCert=ssh-rsa-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB..."); The algorithm such as ssh-rsa-cert-v01@openssh.com in the previous string is used as part of the authentication process. To use a different algorithm, simply change this value. For instance, all of the following are acceptable with the same signed public key:

  • ssh-rsa-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...
  • rsa-sha2-256-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...
  • rsa-sha2-512-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...

SSHAcceptAnyServerHostKey:   If set the class will accept any key presented by the server.

The default value is "False". Set this to "True" to accept any key presented by the server.

SSHAcceptServerCAKey:   The CA public key that signed the server's host key.

If the server's host key was signed by a CA, this configuration setting may be used to specify the CA's public key. If specified, the class will trust any server's host key that was signed by the CA. For instance: component.Config("SSHAcceptServerCAKey=ssh-rsa AAAAB3NzaC1yc2EAAAADAQAB...");

SSHAcceptServerHostKeyFingerPrint:   The fingerprint of the server key to accept.

This configuration setting may be set to a comma-delimited collection of 16-byte MD5 fingerprints that should be accepted as the host's key. You may supply it by hex- encoding the values in the form "0a:1b:2c:3d". Example 2. Accepting Fingerprints: SSHClient.Config("SSHAcceptServerHostKeyFingerprint=0a:1b:2c:3d"); If the server's fingerprint matches one of the values supplied, the class will accept the host key.

SSHFingerprintHashAlgorithm:   The algorithm used to calculate the fingerprint.

This configuration setting controls which hash algorithm is used to calculate the hostkey's fingerprint, displayed when on_ssh_server_authentication fires. Valid values are as follows:

  • MD5
  • SHA1
  • SHA256 (default)
SSHFingerprintMD5:   The server hostkey's MD5 fingerprint.

This configuration setting may be queried in on_ssh_server_authentication to get the server hostkey's MD5 fingerprint.

SSHFingerprintSHA1:   The server hostkey's SHA1 fingerprint.

This configuration setting may be queried in on_ssh_server_authentication to get the server hostkey's SHA-1 fingerprint.

SSHFingerprintSHA256:   The server hostkey's SHA256 fingerprint.

This configuration setting may be queried in on_ssh_server_authentication to get the server hostkey's SHA-256 fingerprint.

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

This configuration 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 class will continue to send keep-alive packets until SSHKeepAliveCountMax is reached. If this is reached, the class will assume the connection is broken and disconnect. The default value is 5.

SSHKeepAliveInterval:   The interval between keep alive packets.

This configuration setting specifies the number of seconds between keep alive packets. If set to a positive value, the class will send a SSH keep-alive packet after KeepAliveInterval seconds of inactivity. This configuration setting takes effect only when there is no activity; if any data are 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 class uses a default value of 30.

SSHKeyExchangeAlgorithms:   Specifies the supported key exchange algorithms.

This configuration setting may be used to specify the list of supported key exchange algorithms used during Secure Shell (SSH) negotiation. The value should contain a comma-separated list of algorithms. Supported algorithms are as follows:

  • 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==
The default value is curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,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==.
SSHKeyRenegotiate:   Causes the component to renegotiate the SSH keys.

Once this configuration setting is queried, the component will renegotiate the SSH keys with the remote host.

Example 3. Renegotiating SSH Keys: SSHClient.Config("SSHKeyRenegotiate")

SSHMacAlgorithms:   Specifies the supported Mac algorithms.

This configuration setting 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 as follows:

  • 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
  • hmac-sha2-256-96-etm@openssh.com
  • hmac-sha2-512-96-etm@openssh.com
  • umac-64@openssh.com
  • umac-64-etm@openssh.com
  • umac-128@openssh.com
  • umac-128-etm@openssh.com
The default value is hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5,hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256-96,hmac-sha2-512-96,hmac-ripemd160-96,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-64@openssh.com,umac-64-etm@openssh.com,umac-128@openssh.com,umac-128-etm@openssh.com.
SSHPubKeyAuthSigAlgorithms:   Specifies the enabled signature algorithms that may be used when attempting public key authentication.

This setting specifies a list of signature algorithms that may be used 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. At runtime, the class will evaluate the specified algorithms, and if the algorithm is applicable to the certificate specified in ssh_cert, it will be used. If the algorithm is not applicable, the class will evaluate the next algorithm. Possible values are as follows:

  • 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,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519.

rsa-sha2-256 and rsa-sha2-512 notes

The class will query the server for supported algorithms when connecting. If the server indicates support for rsa-sha2-256 or rsa-sha2-512 and the algorithm is present in the list defined by this setting (as in the default value), that algorithm will be used instead of ssh-rsa even when ssh-rsa appears first in the list.

For the rsa-sha2-256 and rsa-sha2-512 algorithms to be automatically preferred, the server must support the ext-info-c mechanism. In practice, older servers do not support this, and in that case, ssh-rsa will be used because it appears first in the list. Newer servers do support this mechanism, and in that case, rsa-sha2-256 or rsa-sha2-512 will be used even though it appears after ssh-rsa.

This behavior has been carefully designed to provide maximum compatibility while automatically using more secure algorithms when connecting to servers that support them.

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

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

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

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

*SSH-1.99-*,*SSH-2.0-*,*SSH-2.99-*
TryAllAvailableAuthMethods:   If set to true, the class will try all available authentication methods.

The default value is False. When set to True, the class will try to authenticate using all methods that it has credentials for and the server supports.

UseStrictKeyExchange:   Specifies how strict key exchange is supported.

This configuration setting controls whether strict key exchange (strict kex) is enabled to mitigate the Terrapin attack. When enabled, the class will indicate support for strict key exchange by automatically including the pseudo-algorithm kex-strict-c-v00@openssh.com for client classes and kex-strict-s-v00@openssh.com for server classes in the list of supported key exchange algorithms.

Because both client and server must implement strict key exchange to effectively mitigate the Terrapin attack, the class provides options to further control the behavior in different scenarios. Possible values for this setting are as follows:

0Disabled. Strict key exchange is not supported in the class.
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.
2Enabled, but will 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 continue only if the selected encryption and message authentication code (MAC) algorithms are not affected by the Terrapin attack.
3Required. If the remote host does not support strict key exchange, the connection will fail.

WaitForChannelClose:   Whether to wait for channels to be closed before disconnected.

This configuration setting controls whether the class will wait for a server response to the SSH_MSG_CHANNEL_CLOSE when disconnecting. When the class disconnects, it will first attempt to close all open channels by sending a SSH_MSG_CHANNEL_CLOSE for each channel. This configuration setting controls whether the class will wait for a server response after sending the messages.

When True (default), the class will wait for a response to the channel close message until the responses have been received, the server closes the connection, or timeout seconds is reached.

When False, the class will still send the channel close messages, but it will not wait for a response and will proceed to close the connection.

WaitForServerDisconnect:   Whether to wait for the server to close the connection.

This configuration setting controls whether to wait for the server to close the connection when ssh_logoff is called.

When set to True, the class will initiate the disconnection sequence by sending SSH_MSG_DISCONNECT, but it will not close the connection and instead will wait for the server to close the connection. Setting this to True may be beneficial in circumstances in which many connections are being established, to avoid port exhaustion when sockets are in a TIME_WAIT state. Allowing the server to close the connection avoids the TIME_WAIT state of socket on the client machine.

When set to False (default), the client will close the connection. It is recommended to use this value unless there is a specific need to change it.

TCPClient Config Settings

ConnectionTimeout:   Sets a separate timeout value for establishing a connection.

When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the class will use timeout for establishing a connection and transmitting/receiving data.

FirewallAutoDetect:   Tells the class whether or not to automatically detect and use firewall system settings, if available.

This configuration setting is provided for use by classs that do not directly expose Firewall properties.

FirewallHost:   Name or IP address of firewall (optional).

If a FirewallHost is given, requested connections will be authenticated through the specified firewall when connecting.

If the FirewallHost setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the FirewallHost setting is set to the corresponding address. If the search is not successful, an error is returned.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

FirewallPassword:   Password to be used if authentication is to be used when connecting through the firewall.

If FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the given firewall. If the authentication fails, the class fails with an error.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

FirewallPort:   The TCP port for the FirewallHost;.

The FirewallPort is set automatically when FirewallType is set to a valid value.

Note: This configuration setting is provided for use by classs that do not directly expose Firewall properties.

FirewallType:   Determines the type of firewall to connect through.

Possible values are as follows:

0No firewall (default setting).
1Connect through a tunneling proxy. FirewallPort is set to 80.
2Connect through a SOCKS4 Proxy. FirewallPort is set to 1080.
3Connect through a SOCKS5 Proxy. FirewallPort is set to 1080.
10Connect through a SOCKS4A Proxy. FirewallPort is set to 1080.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

FirewallUser:   A user name if authentication is to be used connecting through a firewall.

If the FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the Firewall. If the authentication fails, the class fails with an error.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

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

When set, TCPKeepAlive will automatically be set to True. 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 configuration setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. This system default if this value is not specified here is 1 second.

Note: This value is not applicable in macOS.

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

When set, TCPKeepAlive will automatically be set to True. By default, the operating system will determine the time a connection is idle before a Transmission Control Protocol (TCP) keep-alive packet is sent. This system default if this value is not specified here is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds.

Linger:   When set to True, connections are terminated gracefully.

This property controls how a connection is closed. The default is True.

In the case that Linger is True (default), two scenarios determine how long the connection will linger. In the first, if LingerTime is 0 (default), the system will attempt to send pending data for a connection until the default IP timeout expires.

In the second scenario, if LingerTime is a positive value, the system will attempt to send pending data until the specified LingerTime is reached. If this attempt fails, then the system will reset the connection.

The default behavior (which is also the default mode for stream sockets) might result in a long delay in closing the connection. Although the class returns control immediately, the system could hold system resources until all pending data are sent (even after your application closes).

Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you sent (e.g., by a client acknowledgment), setting this property to False might be the appropriate course of action.

LingerTime:   Time in seconds to have the connection linger.

LingerTime is the time, in seconds, the socket connection will linger. This value is 0 by default, which means it will use the default IP timeout.

LocalHost:   The name of the local host through which connections are initiated or accepted.

The local_host setting 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 multihomed hosts (machines with more than one IP interface), setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the local_host setting 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 multihomed hosts (machines with more than one IP interface).

LocalPort:   The port in the local host where the class binds.

This configuration setting must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by local_port after the connection is established.

local_port cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxLineLength:   The maximum amount of data to accumulate when no EOL is found.

MaxLineLength is the size of an internal buffer, which holds received data while waiting for an eol string.

If an eol string is found in the input stream before MaxLineLength bytes are received, the on_data_in event is fired with the EOL parameter set to True, and the buffer is reset.

If no eol is found, and MaxLineLength bytes are accumulated in the buffer, the on_data_in event is fired with the EOL parameter set to False, and the buffer is reset.

The minimum value for MaxLineLength is 256 bytes. The default value is 2048 bytes.

MaxTransferRate:   The transfer rate limit in bytes per second.

This configuration setting can be used to throttle outbound TCP traffic. Set this to the number of bytes to be sent per second. By default, this is not set and there is no limit.

ProxyExceptionsList:   A semicolon separated list of hosts and IPs to bypass when using a proxy.

This configuration setting optionally specifies a semicolon-separated list of hostnames or IP addresses to bypass when a proxy is in use. When requests are made to hosts specified in this property, the proxy will not be used. For instance:

www.google.com;www.nsoftware.com

TCPKeepAlive:   Determines whether or not the keep alive socket option is enabled.

If set to True, the socket's keep-alive option is enabled and keep-alive packets will be sent periodically to maintain the connection. Set KeepAliveTime and KeepAliveInterval to configure the timing of the keep-alive packets.

Note: This value is not applicable in Java.

TcpNoDelay:   Whether or not to delay when sending packets.

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

By default, this configuration setting is set to False.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the class will use IPv4 exclusively. When set to 1, the class will use IPv6 exclusively. To instruct the class to prefer IPv6 addresses, but use IPv4 if IPv6 is not supported on the system, this setting should be set to 2. The default value is 0. Possible values are as follows:

0 IPv4 only
1 IPv6 only
2 IPv6 with IPv4 fallback

Socket Config Settings

AbsoluteTimeout:   Determines whether timeouts are inactivity timeouts or absolute timeouts.

If AbsoluteTimeout is set to True, any method that does not complete within timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for User Datagram Protocol (UDP) ports.

FirewallData:   Used to send extra data to the firewall.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g., headers for custom authentication schemes).

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

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

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

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

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

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

Base Config Settings

BuildInfo:   Information about the product's build.

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

CodePage:   The system code page used for Unicode to Multibyte translations.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

IdentifierName
037IBM EBCDIC - U.S./Canada
437OEM - United States
500IBM EBCDIC - International
708Arabic - ASMO 708
709Arabic - ASMO 449+, BCON V4
710Arabic - Transparent Arabic
720Arabic - Transparent ASMO
737OEM - Greek (formerly 437G)
775OEM - Baltic
850OEM - Multilingual Latin I
852OEM - Latin II
855OEM - Cyrillic (primarily Russian)
857OEM - Turkish
858OEM - Multilingual Latin I + Euro symbol
860OEM - Portuguese
861OEM - Icelandic
862OEM - Hebrew
863OEM - Canadian-French
864OEM - Arabic
865OEM - Nordic
866OEM - Russian
869OEM - Modern Greek
870IBM EBCDIC - Multilingual/ROECE (Latin-2)
874ANSI/OEM - Thai (same as 28605, ISO 8859-15)
875IBM EBCDIC - Modern Greek
932ANSI/OEM - Japanese, Shift-JIS
936ANSI/OEM - Simplified Chinese (PRC, Singapore)
949ANSI/OEM - Korean (Unified Hangul Code)
950ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC)
1026IBM EBCDIC - Turkish (Latin-5)
1047IBM EBCDIC - Latin 1/Open System
1140IBM EBCDIC - U.S./Canada (037 + Euro symbol)
1141IBM EBCDIC - Germany (20273 + Euro symbol)
1142IBM EBCDIC - Denmark/Norway (20277 + Euro symbol)
1143IBM EBCDIC - Finland/Sweden (20278 + Euro symbol)
1144IBM EBCDIC - Italy (20280 + Euro symbol)
1145IBM EBCDIC - Latin America/Spain (20284 + Euro symbol)
1146IBM EBCDIC - United Kingdom (20285 + Euro symbol)
1147IBM EBCDIC - France (20297 + Euro symbol)
1148IBM EBCDIC - International (500 + Euro symbol)
1149IBM EBCDIC - Icelandic (20871 + Euro symbol)
1200Unicode UCS-2 Little-Endian (BMP of ISO 10646)
1201Unicode UCS-2 Big-Endian
1250ANSI - Central European
1251ANSI - Cyrillic
1252ANSI - Latin I
1253ANSI - Greek
1254ANSI - Turkish
1255ANSI - Hebrew
1256ANSI - Arabic
1257ANSI - Baltic
1258ANSI/OEM - Vietnamese
1361Korean (Johab)
10000MAC - Roman
10001MAC - Japanese
10002MAC - Traditional Chinese (Big5)
10003MAC - Korean
10004MAC - Arabic
10005MAC - Hebrew
10006MAC - Greek I
10007MAC - Cyrillic
10008MAC - Simplified Chinese (GB 2312)
10010MAC - Romania
10017MAC - Ukraine
10021MAC - Thai
10029MAC - Latin II
10079MAC - Icelandic
10081MAC - Turkish
10082MAC - Croatia
12000Unicode UCS-4 Little-Endian
12001Unicode UCS-4 Big-Endian
20000CNS - Taiwan
20001TCA - Taiwan
20002Eten - Taiwan
20003IBM5550 - Taiwan
20004TeleText - Taiwan
20005Wang - Taiwan
20105IA5 IRV International Alphabet No. 5 (7-bit)
20106IA5 German (7-bit)
20107IA5 Swedish (7-bit)
20108IA5 Norwegian (7-bit)
20127US-ASCII (7-bit)
20261T.61
20269ISO 6937 Non-Spacing Accent
20273IBM EBCDIC - Germany
20277IBM EBCDIC - Denmark/Norway
20278IBM EBCDIC - Finland/Sweden
20280IBM EBCDIC - Italy
20284IBM EBCDIC - Latin America/Spain
20285IBM EBCDIC - United Kingdom
20290IBM EBCDIC - Japanese Katakana Extended
20297IBM EBCDIC - France
20420IBM EBCDIC - Arabic
20423IBM EBCDIC - Greek
20424IBM EBCDIC - Hebrew
20833IBM EBCDIC - Korean Extended
20838IBM EBCDIC - Thai
20866Russian - KOI8-R
20871IBM EBCDIC - Icelandic
20880IBM EBCDIC - Cyrillic (Russian)
20905IBM EBCDIC - Turkish
20924IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol)
20932JIS X 0208-1990 & 0121-1990
20936Simplified Chinese (GB2312)
21025IBM EBCDIC - Cyrillic (Serbian, Bulgarian)
21027Extended Alpha Lowercase
21866Ukrainian (KOI8-U)
28591ISO 8859-1 Latin I
28592ISO 8859-2 Central Europe
28593ISO 8859-3 Latin 3
28594ISO 8859-4 Baltic
28595ISO 8859-5 Cyrillic
28596ISO 8859-6 Arabic
28597ISO 8859-7 Greek
28598ISO 8859-8 Hebrew
28599ISO 8859-9 Latin 5
28605ISO 8859-15 Latin 9
29001Europa 3
38598ISO 8859-8 Hebrew
50220ISO 2022 Japanese with no halfwidth Katakana
50221ISO 2022 Japanese with halfwidth Katakana
50222ISO 2022 Japanese JIS X 0201-1989
50225ISO 2022 Korean
50227ISO 2022 Simplified Chinese
50229ISO 2022 Traditional Chinese
50930Japanese (Katakana) Extended
50931US/Canada and Japanese
50933Korean Extended and Korean
50935Simplified Chinese Extended and Simplified Chinese
50936Simplified Chinese
50937US/Canada and Traditional Chinese
50939Japanese (Latin) Extended and Japanese
51932EUC - Japanese
51936EUC - Simplified Chinese
51949EUC - Korean
51950EUC - Traditional Chinese
52936HZ-GB2312 Simplified Chinese
54936Windows XP: GB18030 Simplified Chinese (4 Byte)
57002ISCII Devanagari
57003ISCII Bengali
57004ISCII Tamil
57005ISCII Telugu
57006ISCII Assamese
57007ISCII Oriya
57008ISCII Kannada
57009ISCII Malayalam
57010ISCII Gujarati
57011ISCII Punjabi
65000Unicode UTF-7
65001Unicode UTF-8
The following is a list of valid code page identifiers for Mac OS only:
IdentifierName
1ASCII
2NEXTSTEP
3JapaneseEUC
4UTF8
5ISOLatin1
6Symbol
7NonLossyASCII
8ShiftJIS
9ISOLatin2
10Unicode
11WindowsCP1251
12WindowsCP1252
13WindowsCP1253
14WindowsCP1254
15WindowsCP1250
21ISO2022JP
30MacOSRoman
10UTF16String
0x90000100UTF16BigEndian
0x94000100UTF16LittleEndian
0x8c000100UTF32String
0x98000100UTF32BigEndian
0x9c000100UTF32LittleEndian
65536Proprietary

LicenseInfo:   Information about the current license.

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

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
MaskSensitiveData:   Whether sensitive data is masked in log messages.

In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to True to mask sensitive data. The default is True.

This setting only works on these classes: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.

ProcessIdleEvents:   Whether the class uses its internal event loop to process events when the main thread is idle.

If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True.

SelectWaitMillis:   The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.

If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20.

UseFIPSCompliantAPI:   Tells the class whether or not to use FIPS certified APIs.

When set to True, the class will utilize the underlying operating system's certified APIs. Java editions, regardless of OS, utilize Bouncy Castle Federal Information Processing Standards (FIPS), while all other Windows editions make use of Microsoft security libraries.

FIPS mode can be enabled by setting the UseFIPSCompliantAPI configuration setting to True. This is a static setting that applies to all instances of all classes of the toolkit within the process. It is recommended to enable or disable this setting once before the component has been used to establish a connection. Enabling FIPS while an instance of the component is active and connected may result in unexpected behavior.

For more details, please see the FIPS 140-2 Compliance article.

Note: This setting is applicable only on Windows.

Note: Enabling FIPS compliance requires a special license; please contact sales@nsoftware.com for details.

UseInternalSecurityAPI:   Whether or not to use the system security libraries or an internal implementation.

When set to False, the class will use the system security libraries by default to perform cryptographic functions where applicable.

Setting this configuration setting to True tells the class to use the internal implementation instead of using the system security libraries.

On Windows, this setting is set to False by default. On Linux/macOS, this setting is set to True by default.

To use the system security libraries for Linux, OpenSSL support must be enabled. For more information on how to enable OpenSSL, please refer to the OpenSSL Notes section.

SSHReverseTunnel Errors

SSHReverseTunnel Errors

10057   Reconnection limit exceeded for Secure Shell (SSH) tunnel.

SSHClient Errors

1001   Server has disconnected.
1002   Protocol version unsupported or other issue with version string.
1003   Cannot negotiate algorithms.
1005   Selected algorithm unsupported.
1006   Cannot set keys.
1010   Unexpected algorithm.
1011   Cannot create exchange hash.
1012   Cannot make key.
1013   Cannot sign data.
1014   Cannot encrypt packet.
1015   Cannot decrypt packet.
1016   Cannot decompress packet.
1020   Failure to open channel.
1021   Invalid channel Id.
1022   Invalid channel data.
1023   Invalid channel message.
1024   SSH message unimplemented.
1027   Server message unsupported.
1030   Server's host key was rejected. The host key may be accepted within the on_ssh_server_authentication event or using the ssh_accept_server_host_key property.
1031   Cannot verify server's host key.
1032   Authentication failed. Check description for details.
1033   Channel request failed.
1034   Diffie-Hellman exchange failed.
1036   SSH connection failed.
1037   SSH reconnect limit reached.
1038   Elliptic curve Diffie-Hellman exchange failed.
1039   SSH keep-alive limit reached.
1098   Request failure.
1130   Would block error.
1133   Would block, reason: key reExchange.

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

TCPClient Errors

100   You cannot change the remote_port at this time. A connection is in progress.
101   You cannot change the remote_host (Server) at this time. A connection is in progress.
102   The remote_host address is invalid (0.0.0.0).
104   Already connected. If you want to reconnect, close the current connection first.
106   You cannot change the local_port at this time. A connection is in progress.
107   You cannot change the local_host at this time. A connection is in progress.
112   You cannot change MaxLineLength at this time. A connection is in progress.
116   remote_port cannot be zero. Please specify a valid service port number.
117   You cannot change the UseConnection option while the class is active.
135   Operation would block.
201   Timeout.
211   Action impossible in control's present state.
212   Action impossible while not connected.
213   Action impossible while listening.
301   Timeout.
302   Could not open file.
434   Unable to convert string to selected CodePage.
1105   Already connecting. If you want to reconnect, close the current connection first.
1117   You need to connect first.
1119   You cannot change the LocalHost at this time. A connection is in progress.
1120   Connection dropped by remote host.

TCP/IP Errors

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