RC4 Class
Properties Methods Events Config Settings Errors
Encrypt and decrypt data with the RC4 (ARC4 / ARCFOUR ) stream cipher.
Syntax
class 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:
- output_file
- output_message: 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 key_password. When key_password 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.
| input_file | The file to process. |
| input_message | The message to process. |
| iv | The initialization vector (IV). |
| key | The secret key for the symmetric algorithm. |
| key_password | A password to generate the Key and IV . |
| output_file | The output file when encrypting or decrypting. |
| output_message | The output message after processing. |
| overwrite | Indicates whether or not the class should overwrite files. |
| use_hex | Whether 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.
| config | Sets or retrieves a configuration setting. |
| decrypt | Decrypts the data. |
| decrypt_block | Decrypts a block and returns the decrypted data. |
| encrypt | Encrypts the data. |
| encrypt_block | Encrypts data and returns the encrypted block. |
| 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.
| on_error | Information about errors during data delivery. |
| on_progress | Fired 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.
| KeySize | The size, in bits, of secret key for the symmetric algorithm. |
| BuildInfo | Information about the product's build. |
| CodePage | The system code page used for Unicode to Multibyte translations. |
| LicenseInfo | Information about the current license. |
| ProcessIdleEvents | Whether the class uses its internal event loop to process events when the main thread is idle. |
| SelectWaitMillis | The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process. |
| UseInternalSecurityAPI | Tells the class whether or not to use the system security libraries or an internal implementation. |
input_file Property
The file to process.
Syntax
def get_input_file() -> str: ... def set_input_file(value: str) -> None: ...
input_file = property(get_input_file, set_input_file)
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:
- input_file
- input_message
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
input_message Property
The message to process.
Syntax
def get_input_message() -> bytes: ... def set_input_message(value: bytes) -> None: ...
input_message = property(get_input_message, set_input_message)
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:
- input_file
- input_message
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
iv Property
The initialization vector (IV).
Syntax
def get_iv() -> bytes: ... def set_iv(value: bytes) -> None: ...
iv = property(get_iv, set_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 key_password or key is set before encrypt or encrypt_block is called. The size of the IV property must be equal to the BlockSize divided by 8.
key Property
The secret key for the symmetric algorithm.
Syntax
def get_key() -> bytes: ... def set_key(value: bytes) -> None: ...
key = property(get_key, set_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 key_password 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.
key_password Property
A password to generate the Key and IV .
Syntax
def get_key_password() -> str: ... def set_key_password(value: str) -> None: ...
key_password = property(get_key_password, set_key_password)
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.
output_file Property
The output file when encrypting or decrypting.
Syntax
def get_output_file() -> str: ... def set_output_file(value: str) -> None: ...
output_file = property(get_output_file, set_output_file)
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:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
output_message Property
The output message after processing.
Syntax
def get_output_message() -> bytes: ...
output_message = property(get_output_message, None)
Default Value
""
Remarks
This property will be populated with the output from the operation if output_file 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:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
This property is read-only.
overwrite Property
Indicates whether or not the class should overwrite files.
Syntax
def get_overwrite() -> bool: ... def set_overwrite(value: bool) -> None: ...
overwrite = property(get_overwrite, set_overwrite)
Default Value
FALSE
Remarks
This property indicates whether or not the class will overwrite output_file. If overwrite is False, an error will be thrown whenever output_file exists before an operation. The default value is False.
use_hex Property
Whether input or output is hex encoded.
Syntax
def get_use_hex() -> bool: ... def set_use_hex(value: bool) -> None: ...
use_hex = property(get_use_hex, set_use_hex)
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. output_message or output_file will hold hex encoded data.
If set to True, when decrypt is called the class will expect input_message or input_file to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.
config Method
Sets or retrieves a configuration setting.
Syntax
def config(configuration_string: str) -> str: ...
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
Decrypts the data.
Syntax
def decrypt() -> None: ...
Remarks
This method will decrypt the specified data. The following properties are applicable:
Note that cipher_mode must be set to the same value used during encryption or the results may be unexpected. If the cipher_mode 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:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
decrypt_block Method
Decrypts a block and returns the decrypted data.
Syntax
def decrypt_block(input_buffer: bytes) -> bytes: ...
Remarks
This method decrypted the data specified by InputBuffer and returns the decrypted data.
encrypt Method
Encrypts the data.
Syntax
def encrypt() -> None: ...
Remarks
This method will encrypt the specified data. The following properties are applicable:
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:
- output_file
- output_message: The output data is written to this property if no other destination is specified.
encrypt_block Method
Encrypts data and returns the encrypted block.
Syntax
def encrypt_block(input_buffer: bytes) -> bytes: ...
Remarks
This method encrypts the data specified by InputBuffer and returns the encrypted block.
reset Method
Resets the class.
Syntax
def reset() -> None: ...
Remarks
When called, the class will reset all of its properties to their default values.
on_error Event
Information about errors during data delivery.
Syntax
class RC4ErrorEventParams(object): @property def error_code() -> int: ... @property def description() -> str: ... # In class RC4: @property def on_error() -> Callable[[RC4ErrorEventParams], None]: ... @on_error.setter def on_error(event_hook: Callable[[RC4ErrorEventParams], None]) -> None: ...
Remarks
The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.
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.
on_progress Event
Fired as progress is made.
Syntax
class RC4ProgressEventParams(object): @property def bytes_processed() -> int: ... @property def percent_processed() -> int: ... # In class RC4: @property def on_progress() -> Callable[[RC4ProgressEventParams], None]: ... @on_progress.setter def on_progress(event_hook: Callable[[RC4ProgressEventParams], None]) -> None: ...
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.
RC4 Config Settings
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 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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 key_password is specified. Note that when using the EzCrypt class, KeySize should be set after setting the algorithm property. |
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CodePage:
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:
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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:
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| ProcessIdleEvents: Whether the class uses its internal event loop to process events when the main thread is idle.If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SelectWaitMillis: The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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 where applicable. Setting this to True tells the class to use the internal implementation instead of using the system's security API. |
RC4 Errors
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. |