SSHAuth ConfigurationThe 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.
SSHAuth Configuration Settings
A comma-separated list containing all allowable compression algorithms.During the SSH handshake, this list will be used to negotiate the compression
algorithm to be used between the client and server.
This list is used for both directions: client to server and server to client.
When negotiating algorithms, each side sends a list of all algorithms it
supports or allows. The algorithm chosen for each direction is the first
algorithm to appear in the sender's list that the receiver supports, so it is
important to list multiple algorithms in preferential order. If no algorithm
can be agreed upon, the 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:
SSHClient Configuration Settings
|ClientSSHVersionString: The SSH version string used by the class.This configuration setting specifies the SSH version string used by the class. The default value is "SSH-2.0-IPWorks SSH Client 2020".|
Whether to use a key stored in Pageant to perform client authentication.This 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 below:
Example enabling Pageant:
component.Config("EnablePageantAuth=1"); component.SSHUser = "sshuser"; component.SSHLogon("localhost", 22);
Note: This functionality is only available 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 that 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 SSHHost property and the kerberos realm used for authentication.|
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):
Specifies the level of detail that is logged.This setting controls the level of detail that is logged through the Log event. Possible values are:
|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.|
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 class
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:
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:
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.|
The length of received data records.If set to a positive value, this setting defines the length of data records to be received. The class 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.
|ServerSSHVersionString: The remote host's SSH version string.This will return the remote host's SSH version string, which can help when identifying problematic servers. This configuration setting is read-only.|
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("SignedSSHCertemail@example.com AAAAB3NzaC1yc2EAAAADAQABAAAB...");The algorithm such as firstname.lastname@example.org in the above 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:
|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.|
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 class will trust any server's host key that was signed by the CA. For instance:
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 class will accept the host key.
The algorithm used to calculate the fingerprint.This configuration setting controls which hash algorithm is used to calculate the hostkey's fingerprint, displayed when SSHServerAuthentication fires.
Valid values are:
|SSHFingerprintMD5: The server hostkey's MD5 fingerprint.This setting may be queried in SSHServerAuthentication to get the server hostkey's MD5 fingerprint.|
|SSHFingerprintSHA1: The server hostkey's SHA1 fingerprint.This setting may be queried in SSHServerAuthentication to get the server hostkey's SHA1 fingerprint.|
|SSHFingerprintSHA256: The server hostkey's SHA256 fingerprint.This setting may be queried in SSHServerAuthentication to get the server hostkey's SHA256 fingerprint.|
|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 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.|
The interval between keep alive packets.This 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 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 class uses a default value of 30.
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:
Causes the component to renegotiate the SSH keys.Once this setting is set the component will renegotiate the SSH keys with the remote host.
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:
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 SSHCert it will be used. If the algorithm is not applicable the class will evaluate the next algorithm. Possible values are:
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 since 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 which support them.
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-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.
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 below value would accept connections for SSH 1.99, 2.0, and 2.99 hosts.
|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.|
Whether to wait for channels to be closed before disconnected.This 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 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 will not wait for a response and will proceed to close the connection.
Whether to wait for the server to close the connection.This setting controls whether to wait for the server to close the connection when SSHLogoff is called.
When set to True the class will initiate the disconnection sequence by sending SSH_MSG_DISCONNECT but 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 where 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.
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 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 is the same as FirewallAutoDetect. This setting is provided for use by classs that do not directly expose Firewall properties.|
Name or IP address of firewall (optional).If a FirewallHost is given, requested connections will be authenticated through the specified firewall
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 classs that do not directly expose Firewall properties.
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 is the same as FirewallPassword. This setting is provided for use by classs that do not directly expose Firewall properties.
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 classs that do not directly expose Firewall properties.
Determines the type of firewall to connect through.The appropriate values are as follows:
NOTE: This is the same as FirewallFirewallType. This setting is provided for use by classs that do not directly expose Firewall properties.
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 is the same as FirewallUser. This setting is provided for use by classs that do not directly expose Firewall properties.
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.
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.
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 class 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.|
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 class initiate connections (or accept in the case of server classs) only through that interface.
If the class 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).
The port in the local host where the class binds.
This 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 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.
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
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.
|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.|
A semicolon separated list of hosts and IPs to bypass when using a proxy.This 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:
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.
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.
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:
Socket Configuration Settings
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).|
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 class is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.
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 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 Configuration Settings
|BuildInfo: Information about the product's build.When queried, this setting will return a string containing information about the product's build.|
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:
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:
|UseInternalSecurityAPI: Tells the class whether or not to use the system security libraries or an internal implementation. By default the class will use the system security libraries to perform cryptographic functions. Setting this to True tells the class to use the internal implementation instead of using the system's security API.|