NetCmdlets 2016
NetCmdlets 2016
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Invoke-SSH Configuration

The cmdlet 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 cmdlet, access to these internal properties is provided through the Config method.

InvokeSSH Configuration Settings

SexecExitStatusVar:   The name of a variable to store the exit status of a command executed via the SExec protocol.

When a command is issued over SExec (ie, no ShellPrompt parameter was specified) the exit code of the completed command will be stored in the specified variable.

TerminalHeight:   The height of the terminal display.

When a connection to the SSH server is made, this option specifies the height of the terminal's display in rows. This configuration option is only valid when used with Connect-SSH.

TerminalWidth:   The width of the terminal display.

When a connection to the SSH server is made, this option specifies the width of the terminal's display in columns. This configuration option is only valid when used with Connect-SSH.

TerminalUsePixel:   Whether the terminal's dimensions are in columns/rows or pixels.

When this option is true the TerminalHeight and TerminalWidth configuration options are in pixels instead of columns/rows. The default is false.

SExec Configuration Settings

TerminalModes:   The terminal mode to set when communicating with the SSH host.

This may be set to specify a terminal mode when communicating with the SSH host. The value passed to this setting is in the form opcode=value. For instance:


cmdlet.Config("TerminalModes=53=0");
In the above example 53 is the opcode (for echo) and the value is 0. So this sets echo to off.

EncodedTerminalModes:   The terminal mode to set when communicating with the SSH host.

This may be set to specify a terminal mode when communicating with the SSH host. This will automatically be set if TerminalModes is set. This is provided as an alternative to TerminalModes. For instance:


cmdlet.Config("EncodedTerminalModes=" + Encoding.Default.GetString(new byte[] { 53,0,0,0,0,0 })");
In the above example the first byte is the opcode (53 for echo). The next 4 bytes represent the opcode value which is a uint 32. The last byte is always a null character to end the string. This example sets echo to off just as in the example for TerminalModes.

TerminalHeight:   The height of the terminal display.

When a connection to the SSH server is made, this option specifies the height of the terminal's display in rows.

TerminalWidth:   The width of the terminal display.

When a connection to the SSH server is made, this option specifies the width of the terminal's display in columns.

TerminalUsePixel:   Whether the terminal's dimensions are in columns/rows or pixels.

When this option is true the TerminalHeight and TerminalWidth configuration options are in pixels instead of columns/rows. The default is false.

SSHClient Configuration Settings

ClientSSHVersionString:   The SSH version string used by the cmdlet.

This configuration setting specifies the SSH version string used by the cmdlet. The default value is "SSH-2.0-IP*Works! SSH Client 2016".

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

When authenticating via public key authentication this setting may be set to the 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 AAAAB3NzaC1yc2EAAAADAQABAAAB...");
SSHAcceptServerCAKey:   The CA public key that signed the server's host key.

If the server's host key was signed by a CA, this setting may be used to specify the CA's public key. If specified the cmdlet will trust any server's host key that was signed by the CA. For instance:

component.Config("SSHAcceptServerCAKey=ssh-rsa AAAAB3NzaC1yc2EAAAADAQAB...");
SSHAcceptAnyServerHostKey:   If set the cmdlet 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.

SSHAcceptServerHostKeyFingerPrint:   The fingerprint of the server key to accept.

This 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:

SSHClient.Config("SSHAcceptServerHostKeyFingerprint=0a:1b:2c:3d");
If the server's fingerprint matches one of the values supplied, the cmdlet will accept the host key.
SSHKeyExchangeAlgorithms:   Specifies the supported key exchange algorithms.

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

  • diffie-hellman-group1-sha1
  • diffie-hellman-group14-sha1
  • diffie-hellman-group-exchange-sha256
  • diffie-hellman-group-exchange-sha1
The default value is: "diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1".
SSHMacAlgorithms:   Specifies the supported Mac algorithms.

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

  • hmac-sha1
  • hmac-md5
  • hmac-sha1-96
  • hmac-md5-96
  • hmac-sha2-256
  • hmac-sha2-256-96
  • hmac-sha2-512
  • hmac-sha2-512-96
  • hmac-ripemd160
  • hmac-ripemd160-96
The default value is "hmac-sha1,hmac-md5,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256-96,hmac-sha2-512-96,hmac-ripemd160-96".
SSHPublicKeyAlgorithms:   Specifies the supported public key algorithms.

This setting specifies the allowed public key algorithms. This list controls only the public key algorithm used when authenticating to the server. This list has no bearing on the public key algorithms that can be used to authenticate the client. The default value is "ssh-rsa,ssh-dss,x509v3-sign-rsa,x509v3-sign-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521".

Note that ECDSA algorithms are only supported in Windows.

SSHKeepAliveInterval:   The interval between keep alive packets.

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

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

Note: The SSHREVERSETUNNEL cmdlet uses a default value of 30.

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

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

SSHKeyRenegotiate:   Causes the component to renegotiate the SSH keys.

Once this setting is set the component will renegotiate the SSH keys with the remote host.

Example:


SSHClient.Config("SSHKeyRenegotiate")

KeyRenegotiationThreshold:   Sets the threshold for the SSH Key Renegotiation.

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

Example (for setting the threshold to 500 MB):


SSHComponent.Config("KeyRenegotiationThreshold=524288000")

SSHPubKeyAuthSigAlgorithms:   Specifies the signature algorithm 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 ordered by preference. At runtime the cmdlet will evaluate each algorithm in the order specified here. If the algorithm is applicable to the certificate specified in SSHCert it will be used. If the algorithm is not applicable the cmdlet will evaluate the next algorithm. Possible values are:

  • ssh-rsa (default)
  • ssh-dss (default)
  • ecdsa-sha2-nistp256 (default - windows only)
  • ecdsa-sha2-nistp384 (default - windows only)
  • ecdsa-sha2-nistp521 (default - windows only)
  • x509v3-sign-rsa
  • x509v3-sign-dss

The default value in Windows is "ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521".

The default value in Unix/macOS/Java is "ssh-rsa,ssh-dss".

Note that ECDSA algorithms are only supported in Windows.

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.

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

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 cmdlet will assume the SPN is based on the value of the SSHHost property and the kerberos realm used for authentication.

LogSSHPackets:   If true, detailed SSH packet logging is performed.

This setting can be enabled to assist in debugging. When set to True the cmdlet will fire the SSHStatus event with detailed information about the SSH level packets. The default value is False.

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

This 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 setting specifies how many bytes of channel data can be sent to the sender of this message without adjusting the window. Note that this value may be changed during the connection, but the window size can only be increased, not decreased.

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

This 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 cmdlet automatically responds to the prompt with the password specified by SSHPassword.

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

The following special characters are supported for pattern matching:

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

If the above characters need to be used as a literal in a pattern then they must be escaped by surrounding them with a []. (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 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 setting defines the length of data records to be received. The cmdlet will accumulate data until RecordLength is reached and only then fire the DataIn 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 DataIn event.

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

IPPort Configuration 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 cmdlet will use Timeout for establishing a connection and transmitting/receiving data.

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

This is the same as FirewallAutoDetect. This setting is provided for use by cmdlets 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 is the same as FirewallHost. This setting is provided for use by cmdlets 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 cmdlet throws an exception.

NOTE: This is the same as FirewallPassword. This setting is provided for use by cmdlets that do not directly expose Firewall properties.

FirewallPort:   The TCP port for the FirewallHost;.

Note that the FirewallPort is set automatically when FirewallType is set to a valid value.

NOTE: This is the same as FirewallPort. This setting is provided for use by cmdlets that do not directly expose Firewall properties.

FirewallType:   Determines the type of firewall to connect through.

The appropriate 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.

NOTE: This is the same as FirewallFirewallType. This setting is provided for use by cmdlets 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 cmdlet throws an exception.

NOTE: This is the same as FirewallUser. This setting is provided for use by cmdlets that do not directly expose Firewall properties.

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 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.

Note: This value is not applicable in Java.

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 acknowledgement is received from the remote host the keep-alive packet will be re-sent. This 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 Java or MAC.

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), there are two scenarios for determining how long the connection will linger. The first, if LingerTime is 0 (default), the system will attempt to send pending data for a connection until the default IP protocol timeout expires.

In the second scenario, 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 cmdlet returns control immediately, the system could hold system resources until all pending data is 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 (by a client acknowledgment, for example), 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, to leave the socket connection linger. This value is 0 by default, which means it will use the default IP protocol timeout.

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

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

If the cmdlet is connected, the LocalHost 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 multi-homed hosts (machines with more than one IP interface).

LocalPort:   The TCP port in the local host where the cmdlet binds.

This must be set before a connection is attempted. It instructs the cmdlet 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 LocalPort after the connection is established.

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

This; setting is useful when trying to connect to services that require a trusted port in 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 DataIn 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 DataIn 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. The maximum value is 65536 bytes.

MaxTransferRate:   The transfer rate limit in bytes per second.

This 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.

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.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the cmdlet will use IPv4 exclusively. When set to 1, the cmdlet will use IPv6 exclusively. To instruct the cmdlet 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:

0 IPv4 Only
1 IPv6 Only
2 IPv6 with IPv4 fallback

TcpNoDelay:   Whether or not to delay when sending packets.

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

By default, this config is set to false.

Socket Configuration Settings

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

If AbsoluteTimeout is set to True, any method which 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 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 TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the cmdlet 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. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

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

 
 
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NetCmdlets 2016 - Version 16.0 [Build 6335]