Kerberos Class

Properties Methods Events Config Settings Errors

The Kerberos class can be used to authenticate users using Kerberos 5.0.

Syntax

ipworksauth.Kerberos

Remarks

The Kerberos class implements the Kerberos protocol defined in RFC 1510 and RFC 4120. The class provides a simple interface to easily authenticate users.

Authentication

When Authenticate is called the class will attempt to authenticate the user with the Key Distribution Center (KDC). The class will communicate with the KDCHost to obtain a service ticket and populate AuthToken. The following properties are required when calling this method:

SPN (required)
User (required)
Password (required)
KDCHost (required)

A typical sequence of messages would be:

KRB_AS_REQ -> KDC
KRB_AS_REP <- KDC
KRB_TGS_REQ -> KDC
KRB_TGS_REP <- KDC
AuthToken is populated with the constructed KRB_AP_REP message.

Communication with the KDCHost can be seen through the PITrail event.

Property List

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


AuthToken	The authentication token.
KDCHost	The domain name or IP address of the Key Distribution Center (KDC).
KDCPort	The port for the Key Distribution Center (KDC).
KeytabFile	The Kerberos Keytab file.
Password	The user's password.
SPN	The Service Principal Name (SPN).
Timeout	A timeout for the class.
User	The name and domain of the user to authenticate.
UseTCP	Whether TCP is used when establishing the connection.

Method List

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


Authenticate	Authenticates the user.
Config	Sets or retrieves a configuration setting.
DoEvents	Processes events from the internal message queue.
Interrupt	Interrupt the current method.
Reset	Resets the class properties to their default values.

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.


Error	Information about errors during data delivery.
Log	Fires once for each log message.
PITrail	Traces the messages sent to the server, and the respective replies.

Config Settings

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


CredentialsCacheFile	The credentials cache file.
EncodeAuthToken	Whether to Base64 encode the AuthToken.
EncryptionTypes	The encryption types used during authentication.
LogKerberosPackets	Whether to include the raw Kerberos packets in PITrail output.
LogLevel	The level of detail that is logged.
UsePlatformKerberosAPI	Whether to use the platform Kerberos API.
UseTCP	Whether TCP is used when establishing the connection.
CaptureIPPacketInfo	Used to capture the packet information.
DelayHostResolution	Whether the hostname is resolved when RemoteHost is set.
DestinationAddress	Used to get the destination address from the packet information.
DontFragment	Used to set the Don't Fragment flag of outgoing packets.
LocalHost	The name of the local host through which connections are initiated or accepted.
LocalPort	The port in the local host where the class binds.
MaxPacketSize	The maximum length of the packets that can be received.
QOSDSCPValue	Used to specify an arbitrary QOS/DSCP setting (optional).
QOSTrafficType	Used to specify QOS/DSCP settings (optional).
ShareLocalPort	If set to True, allows more than one instance of the class to be active on the same local port.
UseConnection	Determines whether to use a connected socket.
UseIPv6	Whether or not to use IPv6.
AbsoluteTimeout	Determines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallData	Used to send extra data to the firewall.
InBufferSize	The size in bytes of the incoming queue of the socket.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
BuildInfo	Information about the product's build.
GUIAvailable	Tells the class whether or not a message loop is available for processing events.
LicenseInfo	Information about the current license.
MaskSensitive	Whether sensitive data is masked in log messages.
UseDaemonThreads	Whether threads created by the class are daemon threads.
UseFIPSCompliantAPI	Tells the class whether or not to use FIPS certified APIs.
UseInternalSecurityAPI	Tells the class whether or not to use the system security libraries or an internal implementation.

AuthToken Property (Kerberos Class)

The authentication token.

Syntax


public byte[] getAuthToken();

Default Value

Remarks

This property holds the authentication token.

This property will be populated after calling Authenticate. This may be used in by another entity to authenticate to the service. For instance this may be used in HTTP to authenticate to a web service.

The content of this property is a KRB_AP_REQ message. This is sometimes referred to as an "Authentication Header". It is comprised of the service ticket that was obtained from the TGS and an encrypted authenticator.

This property is read-only.

KDCHost Property (Kerberos Class)

The domain name or IP address of the Key Distribution Center (KDC).

Syntax


public String getKDCHost();


public void setKDCHost(String KDCHost);

Default Value

Remarks

This property specifies the IP address (IP number in dotted internet format) or Domain Name of the Key Distribution Center (KDC).

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

KDCPort Property (Kerberos Class)

The port for the Key Distribution Center (KDC).

Syntax


public int getKDCPort();


public void setKDCPort(int KDCPort);

Default Value

Remarks

This property specifies the port for the Key Distribution Center (KDC). The default value is 88.

KeytabFile Property (Kerberos Class)

The Kerberos Keytab file.

Syntax


public String getKeytabFile();


public void setKeytabFile(String keytabFile);

Default Value

Remarks

This property specifies the path to a Kerberos Keytab file. If specified, the credentials are read from this file.

Password Property (Kerberos Class)

The user's password.

Syntax


public String getPassword();


public void setPassword(String password);

Default Value

Remarks

This property specifies the user's password. This must be set before calling Authenticate.

SPN Property (Kerberos Class)

The Service Principal Name (SPN).

Syntax


public String getSPN();


public void setSPN(String SPN);

Default Value

Remarks

This property specifies the Service Principal Name (SPN). This must be set before calling Authenticate.

Timeout Property (Kerberos Class)

A timeout for the class.

Syntax


public int getTimeout();


public void setTimeout(int timeout);

Default Value

Remarks

If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If Timeout is set to a positive value, the class will wait for the operation to complete before returning control.

The class will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the class throws an exception.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

User Property (Kerberos Class)

The name and domain of the user to authenticate.

Syntax


public String getUser();


public void setUser(String user);

Default Value

Remarks

This property specifies the name and realm/domain of the user. The value specified must be in one of the following formats:

user@domain
domain/user

UseTCP Property (Kerberos Class)

Whether TCP is used when establishing the connection.

Syntax


public boolean isUseTCP();


public void setUseTCP(boolean useTCP);

Default Value

False

Remarks

This property specifies whether TCP is used as the transport protocol when establishing the connection. By default this property is False and UDP will be used.

Authenticate Method (Kerberos Class)

Authenticates the user.

Syntax

public void authenticate();

Remarks

This method authenticates the User.

Authentication

SPN (required)
User (required)
Password (required)
KDCHost (required)

A typical sequence of messages would be:

KRB_AS_REQ -> KDC
KRB_AS_REP <- KDC
KRB_TGS_REQ -> KDC
KRB_TGS_REP <- KDC
AuthToken is populated with the constructed KRB_AP_REP message.

Communication with the KDCHost can be seen through the PITrail event.

Config Method (Kerberos Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

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.

DoEvents Method (Kerberos Class)

Processes events from the internal message queue.

Syntax

public void doEvents();

Remarks

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

Interrupt Method (Kerberos Class)

Interrupt the current method.

Syntax

public void interrupt();

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

Reset Method (Kerberos Class)

Resets the class properties to their default values.

Syntax

public void reset();

Remarks

This method resets the properties to their default values.

Error Event (Kerberos Class)

Information about errors during data delivery.

Syntax

public class DefaultKerberosEventListener implements KerberosEventListener {
  ...
  public void error(KerberosErrorEvent e) {}
  ...
}

public class KerberosErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws an exception.

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

Log Event (Kerberos Class)

Fires once for each log message.

Syntax

public class DefaultKerberosEventListener implements KerberosEventListener {
  ...
  public void log(KerberosLogEvent e) {}
  ...
}

public class KerberosLogEvent {
  public int logLevel;
  public String message;
  public String logType;
}

Remarks

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

LogLevel indicates the level of the Message. Possible values are:


0 (None)	No events are logged.
1 (Info - default)	Informational events are logged.
2 (Verbose)	Detailed data are logged.
3 (Debug)	Debug data are logged.

The value 1 (Info) logs basic information, including the URL, HTTP version, and status details.

The value 2 (Verbose) logs additional information about the request and response.

The value 3 (Debug) logs the headers and body for both the request and response, as well as additional debug information (if any).

LogType identifies the type of log entry. Possible values are:

Info
Verbose
Debug

PITrail Event (Kerberos Class)

Traces the messages sent to the server, and the respective replies.

Syntax

public class DefaultKerberosEventListener implements KerberosEventListener {
  ...
  public void PITrail(KerberosPITrailEvent e) {}
  ...
}

public class KerberosPITrailEvent {
  public int direction;
  public String message;
}

Remarks

The PITrail event is useful for debugging purposes. It shows all the interaction between the client and the server. To include the raw packets set LogKerberosPackets to True.

The Message parameter contains the full text of the message. The Direction parameter shows the originator of the message:


0 (Client)	The Message originates from the client.
1 (Server)	The Message originates from the server.
2 (Info)	The Message is an informative message originating from the client software (the class code).

Config Settings (Kerberos Class)

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.

KERBEROS Config Settings

CredentialsCacheFile: The credentials cache file.

This setting specifies the path to a credentials cache file. If specified, the credentials are read from this file.

EncodeAuthToken: Whether to Base64 encode the AuthToken.

This setting specifies whether AuthToken is Base64 encoded after calling Authenticate. The default value is False.

EncryptionTypes: The encryption types used during authentication.

This setting specifies a comma separated list of encryption types used during authentication. Possible values are:

rc4-hmac
des-cbc-md5
aes128-cts-hmac-sha1-96

The default value is "des-cbc-md5,rc4-hmac,aes128-cts-hmac-sha1-96".

LogKerberosPackets: Whether to include the raw Kerberos packets in PITrail output.

This settings specifies whether to include the raw Kerberos packet in the Message parameter of the PITrail event. When True the Kerberos packet will be encoded and present in the Message parameter. The default value is False. This may be enabled for troubleshooting purposes.

LogLevel: The level of detail that is logged.

This setting controls the level of detail that is logged through the Log event. Possible values are:


0 (None)	No events are logged.
1 (Info - default)	Informational events are logged.
2 (Verbose)	Detailed data are logged.
3 (Debug)	Debug data are logged.

The value 1 (Info) logs basic information, including the URL, HTTP version, and status details.

The value 2 (Verbose) logs additional information about the request and response.

The value 3 (Debug) logs the headers and body for both the request and response, as well as additional debug information (if any).

UsePlatformKerberosAPI: Whether to use the platform Kerberos API.

This setting determines if the platform's Kerberos API is used. By default the class does not rely on any platform APIs to perform Kerberos authentication. Use of the platform API may be enabled by setting this to True. The default value is False.

Note: This functionality is only available on Windows.

UseTCP: Whether TCP is used when establishing the connection.

This config specifies whether TCP is used as the transport protocol when establishing the connection. By default this config is False and UDP will be used.

UDP Config Settings

CaptureIPPacketInfo: Used to capture the packet information.

If this is set to true, the component will capture the IP packet information.

The default value for this setting is False.

Note: This setting is only available in Windows.

DelayHostResolution: Whether the hostname is resolved when RemoteHost is set.

This setting specifies whether a hostname is resolved immediately when RemoteHost is set. If true the class will resolve the hostname and the IP address will be present in the RemoteHost property. If false, the hostname is not resolved until needed by the component when a method to connect or send data is called. If desired, ResolveRemoteHost may called to manually resolve the value in RemoteHost at any time.

The default value is false.

DestinationAddress: Used to get the destination address from the packet information.

If CaptureIPPacketInfo is set to true, then this will be populated with the packet's destination address when a packet is received. This information will be accessible in the DataIn event.

Note: This setting is only available in Windows.

DontFragment: Used to set the Don't Fragment flag of outgoing packets.

When set to True, packets sent by the class will have the Don't Fragment flag set. The default value is False.

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 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).

LocalPort: 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.

MaxPacketSize: The maximum length of the packets that can be received.

This setting specifies the maximum size of the datagrams that the class will accept without truncation.

QOSDSCPValue: Used to specify an arbitrary QOS/DSCP setting (optional).

UseConnection must be True to use this setting. This option allows you to specify an arbitrary DSCP value between 0 and 63. The default is 0. When set to the default value the component will not set a DSCP value.

Note: This setting uses the qWAVE API is only available on Windows 7, Windows Server 2008 R2, and later.

QOSTrafficType: Used to specify QOS/DSCP settings (optional).

UseConnection must be True to use this setting. You may specify either the text or integer values: BestEffort (0), Background (1), ExcellentEffort (2), AudioVideo (3), Voice (4), and Control (5).

Note: This setting uses the qWAVE API which is only available on Windows Vista and Windows Server 2008 or above.

Note: QOSTrafficType must be set before setting Active to true.

ShareLocalPort: If set to True, allows more than one instance of the class to be active on the same local port.

This option must be set before the class is activated through the Active property or it will have no effect.

The default value for this setting is False.

UseConnection: Determines whether to use a connected socket.

UseConnection specifies whether the class should use a connected socket or not. The connection is defined as an association in between the local address/port and the remote address/port. As such, this is not a connection in the traditional TCP sense. What it means is only that the class will send and receive data only to and from the specified destination.

The default value for this setting is False.

UseIPv6: Whether or not to use IPv6.

By default, the component expects an IPv4 address for local and remote host properties, and will create an IPv4 socket. To use IPv6 instead, set this to True.

Socket Config 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 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. 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 Config Settings

BuildInfo: Information about the product's build.

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

GUIAvailable: Tells the class whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The class will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the class does not attempt to process external events.

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.

MaskSensitive: 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.

UseDaemonThreads: Whether threads created by the class are daemon threads.

If set to True (default), when the class creates a thread, the thread's Daemon property will be explicitly set to True. When set to False, the class will not set the Daemon property on the created thread. The default value is True.

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 FIPS, while all the other Windows editions make use of Microsoft security libraries.

The Java edition requires installation of the FIPS certified Bouncy Castle library regardless of the target operating system. This can be downloaded from https://www.bouncycastle.org/fips-java/. Only the "Provider" library is needed. The jar file should then be installed in a JRE search path.

In the application where the component will be used the following classes must be imported:

import java.security.Security; import org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider;

The Bouncy Castle provider must be added as a valid provider and must also be configured to operate in FIPS mode:

System.setProperty("org.bouncycastle.fips.approved_only","true"); Security.addProvider(new BouncyCastleFipsProvider());

When UseFIPSCompliantAPI is true, SSL enabled classes can optionally be configured to use the TLS Bouncy Castle library. When SSLProvider is set to sslpAutomatic (default) or sslpInternal an internal TLS implementation is used, but all cryptographic operations are offloaded to the BCFIPS provider in order to achieve FIPS compliant operation. If SSLProvider is set to sslpPlatform the Bouncy Castle JSSE will be used in place of the internal TLS implementation.

To enable the use of the Bouncy Castle JSSE take the following steps in addition to the steps above. Both the Bouncy Castle FIPS provider and the Bouncy Castle JSSE must be configured to use the Bouncy Castle TLS library in FIPS mode. Obtain the Bouncy Castle TLS library from https://www.bouncycastle.org/fips-java/. The jar file should then be installed in a JRE search path.

In the application where the component will be used the following classes must be imported:

import java.security.Security; import org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider; //required to use BCJSSE when SSLProvider is set to sslpPlatform import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;

The Bouncy Castle provider must be added as a valid provider and must also be configured to operate in FIPS mode:

System.setProperty("org.bouncycastle.fips.approved_only","true"); Security.addProvider(new BouncyCastleFipsProvider()); //required to use BCJSSE when SSLProvider is set to sslpPlatform Security.addProvider(new BouncyCastleJsseProvider("fips:BCFIPS")); //optional - configure logging level of BCJSSE Logger.getLogger("org.bouncycastle.jsse").setLevel(java.util.logging.Level.OFF); //configure the class to use BCJSSE component.setSSLProvider(1); //platform component.config("UseFIPSCompliantAPI=true"); Note: TLS 1.3 support requires the Bouncy Castle TLS library version 1.0.14 or later.

FIPS mode can be enabled by setting the UseFIPSCompliantAPI configuration setting to true. This is a static setting which 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: Enabling FIPS-compliance requires a special license; please contact sales@nsoftware.com for details.

UseInternalSecurityAPI: Tells the class 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 setting to true tells the class to use the internal implementation instead of using the system security libraries.

This setting is set to false by default on all platforms.

Trappable Errors (Kerberos Class)

kerberos Errors


	950 Busy performing other action.
	951 Invalid username.
	952 Received error message. The error message contains the description.
	953 Message integrity check error.
	954 Unsupported encryption type.

UDP Errors


	104 UDP is already Active.
	106 You cannot change the LocalPort while the class is Active.
	107 You cannot change the LocalHost at this time. A connection is in progress.
	109 The class must be Active for this operation.
	112 Cannot change MaxPacketSize while the class is Active.
	113 Cannot change ShareLocalPort option while the class is Active.
	114 Cannot change RemoteHost when UseConnection is set and the class Active.
	115 Cannot change RemotePort when UseConnection is set and the class is Active.
	116 RemotePort can't be zero when UseConnection is set. Please specify a valid service port number.
	117 Cannot change UseConnection while the class is Active.
	118 Message can't be longer than MaxPacketSize.
	119 Message too short.
	434 Unable to convert string to selected CodePage

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 non-socket.
	10039 [10039] Destination address required.
	10040 [10040] Message too long.
	10041 [10041] Protocol wrong type for socket.
	10042 [10042] Bad protocol option.
	10043 [10043] Protocol not supported.
	10044 [10044] Socket type not supported.
	10045 [10045] Operation not supported on socket.
	10046 [10046] Protocol family not supported.
	10047 [10047] Address family not supported by protocol family.
	10048 [10048] Address already in use.
	10049 [10049] Can't 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] Can't send after socket shutdown.
	10059 [10059] Too many references, can't splice.
	10060 [10060] Connection timed out.
	10061 [10061] Connection refused.
	10062 [10062] Too many levels of symbolic links.
	10063 [10063] File name too long.
	10064 [10064] Host is down.
	10065 [10065] No route to host.
	10066 [10066] Directory 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 not loaded yet.
	11001 [11001] Host not found.
	11002 [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
	11003 [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
	11004 [11004] Valid name, no data record (check DNS setup).