CAST Module

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Encrypt and decrypt data with the CAST-128/CAST5 block cipher.

Syntax

IPWorksEncrypt.CAST

Remarks

The CAST component is used to encrypt and decrypt data with the CAST-128/CAST5 block 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:

• InputFile
• InputMessage

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

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

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 module with short descriptions. Click on the links for further details.

Method List

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

Event List

The following is the full list of the events fired by the module with short descriptions. Click on the links for further details.

Config Settings

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

CipherMode Property (CAST Module)

The cipher mode of operation.

Syntax

• Swift
• Objective-C

public var cipherMode: CASTCipherModes {
  get {...}
  set {...}
}

public enum CASTCipherModes: Int32 {
  case cmCBC = 0
  case cmECB = 1
  case cmOFB = 2
  case cmCFB = 3
  case cmCTS = 4
  case cm8OFB = 5
  case cm8CFB = 7
}

@property (nonatomic,readwrite,assign,getter=cipherMode,setter=setCipherMode:) int cipherMode;

- (int)cipherMode;
- (void)setCipherMode :(int)newCipherMode;

Default Value

0

Remarks

The cipher mode of operation.

Possible values are:

InputFile Property (CAST Module)

The file to process.

Syntax

• Swift
• Objective-C

public var inputFile: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=inputFile,setter=setInputFile:) NSString* inputFile;

- (NSString*)inputFile;
- (void)setInputFile :(NSString*)newInputFile;

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:

• InputFile
• InputMessage

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

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

InputMessage Property (CAST Module)

The message to process.

Syntax

• Swift
• Objective-C

public var inputMessage: String {
  get {...}
  set {...}
}

public var inputMessageB: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=inputMessage,setter=setInputMessage:) NSString* inputMessage;

- (NSString*)inputMessage;
- (void)setInputMessage :(NSString*)newInputMessage;

@property (nonatomic,readwrite,assign,getter=inputMessageB,setter=setInputMessageB:) NSData* inputMessageB;

- (NSData*)inputMessageB;
- (void)setInputMessageB :(NSData*)newInputMessage;

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:

• InputFile
• InputMessage

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

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

IV Property (CAST Module)

The initialization vector (IV).

Syntax

• Swift
• Objective-C

public var iv: String {
  get {...}
  set {...}
}

public var ivB: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=IV,setter=setIV:) NSString* IV;

- (NSString*)IV;
- (void)setIV :(NSString*)newIV;

@property (nonatomic,readwrite,assign,getter=IVB,setter=setIVB:) NSData* IVB;

- (NSData*)IVB;
- (void)setIVB :(NSData*)newIV;

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 (CAST Module)

The secret key for the symmetric algorithm.

Syntax

• Swift
• Objective-C

public var key: String {
  get {...}
  set {...}
}

public var keyB: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=key,setter=setKey:) NSString* key;

- (NSString*)key;
- (void)setKey :(NSString*)newKey;

@property (nonatomic,readwrite,assign,getter=keyB,setter=setKeyB:) NSData* keyB;

- (NSData*)keyB;
- (void)setKeyB :(NSData*)newKey;

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)

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 (CAST Module)

A password to generate the Key and IV .

Syntax

• Swift
• Objective-C

public var keyPassword: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=keyPassword,setter=setKeyPassword:) NSString* keyPassword;

- (NSString*)keyPassword;
- (void)setKeyPassword :(NSString*)newKeyPassword;

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 (CAST Module)

The output file when encrypting or decrypting.

Syntax

• Swift
• Objective-C

public var outputFile: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=outputFile,setter=setOutputFile:) NSString* outputFile;

- (NSString*)outputFile;
- (void)setOutputFile :(NSString*)newOutputFile;

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:

• InputFile
• InputMessage

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

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

OutputMessage Property (CAST Module)

The output message after processing.

Syntax

• Swift
• Objective-C

public var outputMessage: String {
  get {...}
}

public var outputMessageB: Data {
  get {...}
}

@property (nonatomic,readonly,assign,getter=outputMessage) NSString* outputMessage;

- (NSString*)outputMessage;

@property (nonatomic,readonly,assign,getter=outputMessageB) NSData* outputMessageB;

- (NSData*)outputMessageB;

Default Value

""

Remarks

This property will be populated with the output from the operation if OutputFile is 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:

• InputFile
• InputMessage

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

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

This property is read-only.

Overwrite Property (CAST Module)

Indicates whether or not the module should overwrite files.

Syntax

• Swift
• Objective-C

public var overwrite: Bool {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=overwrite,setter=setOverwrite:) BOOL overwrite;

- (BOOL)overwrite;
- (void)setOverwrite :(BOOL)newOverwrite;

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.

PaddingMode Property (CAST Module)

The padding mode.

Syntax

• Swift
• Objective-C

public var paddingMode: CASTPaddingModes {
  get {...}
  set {...}
}

public enum CASTPaddingModes: Int32 {
  case pmPKCS7 = 0
  case pmZeros = 1
  case pmNone = 2
  case pmANSIX923 = 3
  case pmISO10126 = 4
}

@property (nonatomic,readwrite,assign,getter=paddingMode,setter=setPaddingMode:) int paddingMode;

- (int)paddingMode;
- (void)setPaddingMode :(int)newPaddingMode;

Default Value

0

Remarks

PaddingMode is used to pad the final input block to guarantee that it is the correct size required for the selected CipherMode. If the input size is a multiple of the cipher's BlockSize, an extra block of padding will be appended to the input. This enables the decrypting agent to know with certainty how many bytes of padding are included. Each mode pads the data differently. Possible values are:

When calling Decrypt the PaddingMode must match the value used when the data was encrypted.

Note: When using a value of 2 (pmNone), unless the length of input is an exact multiple of the cipher's input BlockSize, the final block of plaintext may be lost.

UseHex Property (CAST Module)

Whether input or output is hex encoded.

Syntax

• Swift
• Objective-C

public var useHex: Bool {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=useHex,setter=setUseHex:) BOOL useHex;

- (BOOL)useHex;
- (void)setUseHex :(BOOL)newUseHex;

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 (CAST Module)

Sets or retrieves a configuration setting.

Syntax

• Swift
• Objective-C

public func config(configurationString: String) throws -> String

- (NSString*)config:(NSString*)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 (CAST Module)

Decrypts the data.

Syntax

• Swift
• Objective-C

public func decrypt() throws -> Void

- (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:

• InputFile
• InputMessage

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

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

DecryptBlock Method (CAST Module)

Decrypts a block and returns the decrypted data.

Syntax

• Swift
• Objective-C

public func decryptBlock(inputBuffer: Data, lastBlock: Bool) throws -> Data

- (NSData*)decryptBlock:(NSData*)inputBuffer :(BOOL)lastBlock;

Remarks

This method will decrypt the specified block and return the decrypted data.

InputBuffer specifies the encrypted block to decrypt.

LastBlock indicates whether the block is the last block.

Encrypt Method (CAST Module)

Encrypts the data.

Syntax

• Swift
• Objective-C

public func encrypt() throws -> Void

- (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:

• InputFile
• InputMessage

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

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

EncryptBlock Method (CAST Module)

Encrypts data and returns the encrypted block.

Syntax

• Swift
• Objective-C

public func encryptBlock(inputBuffer: Data, lastBlock: Bool) throws -> Data

- (NSData*)encryptBlock:(NSData*)inputBuffer :(BOOL)lastBlock;

Remarks

This method will encrypt the input data and return the encrypted block.

InputBuffer specifies the input data to encrypt.

LastBlock specifies whether the block is the last block.

Reset Method (CAST Module)

Resets the component.

Syntax

• Swift
• Objective-C

public func reset() throws -> Void

- (void)reset;

Remarks

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

Error Event (CAST Module)

Fired when information is available about errors during data delivery.

Syntax

• Swift
• Objective-C

func onError(errorCode: Int32, description: String)

- (void)onError:(int)errorCode :(NSString*)description;

Remarks

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

The ErrorCode parameter contains an error code, and the Description parameter 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 (CAST Module)

Fired as progress is made.

Syntax

• Swift
• Objective-C

func onProgress(bytesProcessed: Int64, percentProcessed: Int32)

- (void)onProgress:(long long)bytesProcessed :(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 (CAST Module)

CAST Config Settings

Base Config Settings

Trappable Errors (CAST Module)

CAST Errors