EzRand Class

Properties Methods Events Config Settings Errors

The EzRand class can be used to generate random numbers or bytes using a variety of algorithms.

Syntax

ipworksencrypt.Ezrand

Remarks

The EzRand class can be used to generate random numbers or bytes using a variety of algorithms and implementations.

To begin first set the Algorithm property to the desired value. This property specifies the algorithm and implementation that will be used to generate the number or bytes. Possible choices include ISAAC, the Microsoft Crypto API, and platform specific random and secure random implementations.

Next set Min and Max to define the acceptable range of values when generating an integer. The Seed property may optionally be set. Then simply call GetNextInt to generate a random number. the RandInt property will be populated with the generated value.

To generate a random set of bytes set RandBytesLength to the desired number of bytes and call GetNextBytes.

Property List

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


Algorithm	The random number algorithm.
Max	The exclusive upper bound.
Min	The inclusive lower bound.
RandBytes	The random byte array.
RandBytesLength	The length of the byte array to be generated.
RandInt	The random integer.
Seed	The seed.

Method List

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


Config	Sets or retrieves a configuration setting.
GetNextBytes	Generates a sequence of random bytes.
GetNextInt	Generates a random integer.
Reset	Resets the class.

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.

Config Settings

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


OutputEncoding	The encoding applied to the generated bytes.
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.
UseInternalSecurityAPI	Tells the class whether or not to use the system security libraries or an internal implementation.

Algorithm Property (EzRand Class)

The random number algorithm.

Syntax


public int getAlgorithm();


public void setAlgorithm(int algorithm);


Enumerated values:
  public final static int raISAAC = 0;
  public final static int raMSCryptoAPI = 1;
  public final static int raPlatform = 2;
  public final static int raSecurePlatform = 3;
  public final static int raRC4Random = 4;

Default Value

Remarks

This property specifies the algorithm used to generate the random number or bytes. Possible values are:


0 (raISAAC)	ISAAC (indirection, shift, accumulate, add, and count)
1 (raMSCryptoAPI)	The Microsoft Crypto API. This is only available on Windows.
2 (raPlatform)	The platform's random implementation.
3 (raSecurePlatform)	The platform's secure random implementation. This is only applicable in .NET and Java. In .NET the class uses the "RNGCryptoServiceProvider" class. In Java the class uses the "SecureRandom" class.
4 (raRC4Random)	RC4 based random implementation.

Max Property (EzRand Class)

The exclusive upper bound.

Syntax


public int getMax();


public void setMax(int max);

Default Value

100

Remarks

This property specifies the exclusive upper bound of the random integer to be generated. The value must be greater than Min. The default value is 100.

Min Property (EzRand Class)

The inclusive lower bound.

Syntax


public int getMin();


public void setMin(int min);

Default Value

Remarks

This property specifies the inclusive lower bound of the random integer to be generated. The value must be less than Max, and must not be negative. The default value is 0.

RandBytes Property (EzRand Class)

The random byte array.

Syntax


public byte[] getRandBytes();

Default Value

Remarks

This property holds the random byte array generated by calling GetNextBytes.

This property is read-only.

RandBytesLength Property (EzRand Class)

The length of the byte array to be generated.

Syntax


public int getRandBytesLength();


public void setRandBytesLength(int randBytesLength);

Default Value

Remarks

This property specifies the length of the random byte array to be generated. The RandBytes property will hold the byte array after GetNextBytes is called. The default value is 16.

RandInt Property (EzRand Class)

The random integer.

Syntax


public int getRandInt();

Default Value

Remarks

This property holds the random integer generated by calling GetNextInt.

This property is read-only.

Seed Property (EzRand Class)

The seed.

Syntax


public byte[] getSeed();


public void setSeed(byte[] seed);

Default Value

Remarks

This property specifies the seed. This value is optional. If not specified and a seed is required the class will use the current time.

Seed Notes

When Algorithm is set to 0 (raISAAC) the class uses the leftmost 256 bytes.
When Algorithm is set to 1 (raMSCryptoAPI) the seed is ignored.
When Algorithm is set to 2 (raPlatform) the class uses the leftmost 4 bytes.
When Algorithm is set to 3 (raSecurePlatform) in .NET the seed is ignored. The seed is applicable in Java.

Config Method (Ezrand 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.

GetNextBytes Method (Ezrand Class)

Generates a sequence of random bytes.

Syntax

public void getNextBytes();

Remarks

This method generates a new sequence of random bytes. The RandBytesLength property specifies the length of the byte array. After calling this method the RandBytes will hold the random bytes. The following properties are applicable when calling this method:

Algorithm
RandBytesLength
Seed

GetNextInt Method (Ezrand Class)

Generates a random integer.

Syntax

public void getNextInt();

Remarks

This method generates a random integer. The Min and Max properties define the minimum and maximum values. After calling this method the RandInt property will hold the integer. The following properties are applicable when calling this method:

Algorithm
Min
Max
Seed

Reset Method (Ezrand Class)

Resets the class.

Syntax

public void reset();

Remarks

When called, the class will reset all of its properties to their default values.

Error Event (Ezrand Class)

Information about errors during data delivery.

Syntax

public class DefaultEzrandEventListener implements EzrandEventListener {
  ...
  public void error(EzrandErrorEvent e) {}
  ...
}

public class EzrandErrorEvent {
  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.

Config Settings (Ezrand 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.

EzRand Config Settings

OutputEncoding: The encoding applied to the generated bytes.

This setting optionally specifies an encoding to apply to the bytes generated when GetNextBytes is called. This may be useful in situations where the bytes are displayed or transmitted as text. Possible values are:

0 (none - default)
1 (Base64)
2 (Hex)
3 (Base64URL)

The RandBytes property will hold the string.

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.

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 (Ezrand Class)

EzRand Errors


	101 Unsupported algorithm.
	105 Invalid Min, Max, or RandomBytesLength value.