RC4 Class

Properties   Methods   Events   Config Settings   Errors  

Encrypt and decrypt data with the RC4 (ARC4 / ARCFOUR ) stream cipher.

Syntax

ipworksencrypt.Rc4

Remarks

The RC4 component is used to encrypt and decrypt data with the RC4 (ARC4 / ARCFOUR ) stream cipher.

To begin simply specify the data you wish to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Before encrypting you must have a valid Key and IV. There are a few options available to you in regards to key management. The easiest option is to simply set KeyPassword. When KeyPassword is set the component will automatically create a Key and IV using the PKCS5 password digest algorithm. This means there is only one value you need to keep track of.

If you wish to have more control over the Key and IV values you may specify the properties yourself. If IV is left empty, one will be created for you when you call Encrypt or Decrypt.

A simple example: Component.InputFile = "C:\MyFile.txt"; Component.OutputFile = "C:\Encrypted.txt"; Component.KeyPassword = "password"; Component.Encrypt();

Property List


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

InputFileThe file to process.
InputMessageThe message to process.
IVThe initialization vector (IV).
KeyThe secret key for the symmetric algorithm.
KeyPasswordA password to generate the Key and IV .
OutputFileThe output file when encrypting or decrypting.
OutputMessageThe output message after processing.
OverwriteIndicates whether or not the class should overwrite files.
UseHexWhether input or output is hex encoded.

Method List


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

ConfigSets or retrieves a configuration setting.
DecryptDecrypts the data.
DecryptBlockDecrypts a block and returns the decrypted data.
EncryptEncrypts the data.
EncryptBlockEncrypts data and returns the encrypted block.
ResetResets the class.
SetInputStreamSets the stream from which the class will read data to encrypt or decrypt.
SetOutputStreamSets the stream to which the class will write encrypted or decrypted data.

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.

ErrorInformation about errors during data delivery.
ProgressFired as progress is made.

Config Settings


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

CloseInputStreamAfterProcessingDetermines whether or not the input stream is closed after processing.
CloseOutputStreamAfterProcessingDetermines whether or not the output stream is closed after processing.
KeySizeThe size, in bits, of secret key for the symmetric algorithm.
BuildInfoInformation about the product's build.
GUIAvailableTells the class whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
MaskSensitiveWhether sensitive data is masked in log messages.
UseDaemonThreadsWhether threads created by the class are daemon threads.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

InputFile Property (RC4 Class)

The file to process.

Syntax


public String getInputFile();


public void setInputFile(String inputFile);

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

InputMessage Property (RC4 Class)

The message to process.

Syntax


public byte[] getInputMessage();


public void setInputMessage(byte[] inputMessage);

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

IV Property (RC4 Class)

The initialization vector (IV).

Syntax


public byte[] getIV();


public void setIV(byte[] IV);

Default Value

""

Remarks

This property specifies the initialization vector (IV). By default this property is empty and the class will automatically generate a new IV value if KeyPassword or Key is set before Encrypt or EncryptBlock is called. The size of the IV property must be equal to the BlockSize divided by 8.

Key Property (RC4 Class)

The secret key for the symmetric algorithm.

Syntax


public byte[] getKey();


public void setKey(byte[] key);

Default Value

""

Remarks

This secret key is used both for encryption and decryption. The secret key should be known only to the sender and the receiver. The legal key size varies depending on the algorithm.

If this property is left empty and KeyPassword is specified, a Key value will be generated by the class as necessary.

Legal Key and Block Sizes (in bits)

AES Rijndael CAST DES IDEA RC2 RC4 TripleDES Blowfish Twofish TEA
Minimum Key Size 128 128 112 64 128 112 112 128 112 128 128
Maximum Key Size 256 256 128 64 128 128 2048 192 448 256 128
Key Size Step 64 64 8 0 0 8 8 64 1 8 0
Block Size 128 128/192/256 64 64 64 64 N/A 64 64 128 64*

Note: When using TEA if Algorithm is set to XXTEA valid block sizes are 64 + n * 32. Where n is any positive integer.

The default KeySize is the Maximum Key Size.

KeyPassword Property (RC4 Class)

A password to generate the Key and IV .

Syntax


public String getKeyPassword();


public void setKeyPassword(String keyPassword);

Default Value

""

Remarks

When this property is set the class will calculate values for Key and IV using the PKCS5 password digest algorithm. This provides a simpler alternative to creating and managing Key and IV values directly.

The size of the Key generated is dependent on the value of KeySize.

OutputFile Property (RC4 Class)

The output file when encrypting or decrypting.

Syntax


public String getOutputFile();


public void setOutputFile(String outputFile);

Default Value

""

Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

OutputMessage Property (RC4 Class)

The output message after processing.

Syntax


public byte[] getOutputMessage();


Default Value

""

Remarks

This property will be populated with the output from the operation if OutputFile and SetOutputStream are not set.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

This property is read-only and not available at design time.

Overwrite Property (RC4 Class)

Indicates whether or not the class should overwrite files.

Syntax


public boolean isOverwrite();


public void setOverwrite(boolean overwrite);

Default Value

False

Remarks

This property indicates whether or not the class will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.

UseHex Property (RC4 Class)

Whether input or output is hex encoded.

Syntax


public boolean isUseHex();


public void setUseHex(boolean useHex);

Default Value

False

Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when Encrypt is called the class will perform the encryption as normal and then hex encode the output. OutputMessage or OutputFile will hold hex encoded data.

If set to True, when Decrypt is called the class will expect InputMessage or InputFile to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

Config Method (Rc4 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.

Decrypt Method (Rc4 Class)

Decrypts the data.

Syntax

public void decrypt();

Remarks

This method will decrypt the specified data. The following properties are applicable:

  • IV (required)
  • Key (required)
  • CipherMode
  • PaddingMode

Note that CipherMode must be set to the same value used during encryption or the results may be unexpected. If the CipherMode value does not match the value used during encryption the operation may succeed but the decrypted data may not be correct.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

DecryptBlock Method (Rc4 Class)

Decrypts a block and returns the decrypted data.

Syntax

public byte[] decryptBlock(byte[] inputBuffer);

Remarks

This method decrypted the data specified by InputBuffer and returns the decrypted data.

Encrypt Method (Rc4 Class)

Encrypts the data.

Syntax

public void encrypt();

Remarks

This method will encrypt the specified data. The following properties are applicable:

  • IV (required)
  • Key (required)
  • PaddingMode
  • CipherMode

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

EncryptBlock Method (Rc4 Class)

Encrypts data and returns the encrypted block.

Syntax

public byte[] encryptBlock(byte[] inputBuffer);

Remarks

This method encrypts the data specified by InputBuffer and returns the encrypted block.

Reset Method (Rc4 Class)

Resets the class.

Syntax

public void reset();

Remarks

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

SetInputStream Method (Rc4 Class)

Sets the stream from which the class will read data to encrypt or decrypt.

Syntax

public void setInputStream(java.io.InputStream inputStream);

Remarks

This method sets the stream from which the class will read data to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

SetOutputStream Method (Rc4 Class)

Sets the stream to which the class will write encrypted or decrypted data.

Syntax

public void setOutputStream(java.io.OutputStream outputStream);

Remarks

This method sets the stream to which the class will write encrypted or decrypted data.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

  • SetOutputStream
  • OutputFile
  • OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Error Event (Rc4 Class)

Information about errors during data delivery.

Syntax

public class DefaultRc4EventListener implements Rc4EventListener {
  ...
  public void error(Rc4ErrorEvent e) {}
  ...
}

public class Rc4ErrorEvent {
  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.

Progress Event (Rc4 Class)

Fired as progress is made.

Syntax

public class DefaultRc4EventListener implements Rc4EventListener {
  ...
  public void progress(Rc4ProgressEvent e) {}
  ...
}

public class Rc4ProgressEvent {
  public long bytesProcessed;
  public int percentProcessed;
}

Remarks

This event is fired automatically as data is processed by the class.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

Config Settings (Rc4 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.

RC4 Config Settings

CloseInputStreamAfterProcessing:   Determines whether or not the input stream is closed after processing.

Determines whether or not the input stream set by SetInputStream is closed after processing is complete. The default value is True.

CloseOutputStreamAfterProcessing:   Determines whether or not the output stream is closed after processing.

Determines whether or not the output stream set by SetOutputStream is closed after processing is complete. The default value is True.

KeySize:   The size, in bits, of secret key for the symmetric algorithm.

The legal key sizes vary depending on the algorithm. The KeySize and BlockSize configuration settings may be set to specify the key and block size (in bits).

This setting is only applicable when KeyPassword is specified.

Note that when using the EzCrypt class, KeySize should be set after setting the Algorithm property.

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 (Rc4 Class)

RC4 Errors

101   Unsupported algorithm.
102   No Key specified.
103   No IV specified.
104   Cannot read or write file.
107   Block size is not valid for this algorithm.
108   Key size is not valid for this algorithm.
111   OutputFile already exists and Overwrite is False.
121   The specified key is invalid.
123   IV size is not valid for this algorithm.
304   Cannot write file.
305   Cannot read file.
306   Cannot create file.
2004   Invalid padding. This may be an indication that the key is incorrect.