Hash Class

Properties   Methods   Events   Config Settings   Errors  

The Hash class allows you to compute a hash using various algorithms.

Syntax

class ipworksencrypt.Hash

Remarks

The Hash component allows you to compute a hash using various algorithms including SHA1, SHA224, SHA256, SHA384, SHA512, MD2, MD4, MD5, RIPEMD160, MD5SHA1, HMACMD5, HMACSHA1, HMACSHA224, HMACSHA256, HMACSHA384, HMACSHA512, etc.

To begin, first select the algorithm you wish to use when computing the hash. Common choices include MD5 and SHA1. For a full list of supported algorithms see the algorithm property.

Next specify the data to hash. Input Notes

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

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

• input_file
• input_message

When a valid source is found the search stops.

Call the compute_hash method to hash the data. The hash_value property will hold the computed hash. By default the hash value is hex encoded for ease of use, but you may disable this by setting encode_hash to False.

Property List

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

Method List

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

Event List

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

Config Settings

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

algorithm Property

The algorithm used to create the hash.

Syntax

def get_algorithm() -> int: ...
def set_algorithm(value: int) -> None: ...

algorithm = property(get_algorithm, set_algorithm)

Default Value

2

Remarks

This property specifies the algorithm used when calling compute_hash. Possible values are:

encode_hash Property

Whether the hash value is hex encoded.

Syntax

def get_encode_hash() -> bool: ...
def set_encode_hash(value: bool) -> None: ...

encode_hash = property(get_encode_hash, set_encode_hash)

Default Value

TRUE

Remarks

This property specifies whether the computed hash value is hex encoded. When set to True (default) the class will hex encoded the computed hash for easier use. Set this value to False to obtain the hash value in an unmodified form.

The default value is True.

hash_value Property

The hash value.

Syntax

def get_hash_value() -> bytes: ...

hash_value = property(get_hash_value, None)

Default Value

""

Remarks

The computed hash value. This property is populated after calling compute_hash.

This property is read-only.

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 Notes

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

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

• input_file
• input_message

When a valid source is found the search stops.

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 Notes

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

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

• input_file
• input_message

When a valid source is found the search stops.

key Property

The secret key for the hash algorithm.

Syntax

def get_key() -> bytes: ...
def set_key(value: bytes) -> None: ...

key = property(get_key, set_key)

Default Value

""

Remarks

This property holds the secret key used when creating the hash. The key can be arbitrarily long.

Note: This property is only applicable when algorithm is set to an HMAC algorithm.

It is recommended that the length of the key be equal to or larger than the hash size of the algorithm. Use of keys shorter than the hash size is discouraged.

Sizes (in bytes)

Key Length Details

As mentioned above it is recommended to use a key size equal to the hash size. Use of keys larger than the hash size does not typically significantly increase the function strength. Keys of any length are technically valid however see the below processing rules to understand how keys of varying lengths are treated:

• If the key length is equal to the hash size (recommended) it is used without modification.
• If the key length is less than the hash size it is used without modification.
• If the key length is less than or equal to the block size it is used without modification.
• If the key length is larger than the block size is it first hashed with the same algorithm.

compute_hash Method

Computes a hash.

Syntax

def compute_hash() -> None: ...

Remarks

This method computes a hash of the data specified by input_message or input_file. The algorithm used is specified by algorithm. The hash_value property will be populated with the computed hash.

Input Notes

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

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

• input_file
• input_message

When a valid source is found the search stops.

The on_progress event will fire with updates during this operation.

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.

hash_block Method

Computes the hash value of specified data.

Syntax

def hash_block(input_buffer: bytes, last_block: bool) -> bytes: ...

Remarks

This method will compute the hash value of the input data. This method will return the hash value only when the parameter LastBlock is True.

InputBuffer specifies the input data.

LastBlock specifies whether the block is the last block. If this is False the method will return an empty byte array.

To calculate the hash value of data that is broken apart into multiple blocks make multiple calls to this method. For instance: Hash.HashBlock(part1,false); Hash.HashBlock(part2,false); Hash.HashBlock(part3,false); byte[] hashValue = Hash.HashBlock(lastPart,true);

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

Fired when information is available about errors during data delivery.

Syntax

class HashErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class Hash:
@property
def on_error() -> Callable[[HashErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[HashErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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.

on_progress Event

Fired as progress is made.

Syntax

class HashProgressEventParams(object):
  @property
  def bytes_processed() -> int: ...

  @property
  def percent_processed() -> int: ...

# In class Hash:
@property
def on_progress() -> Callable[[HashProgressEventParams], None]: ...
@on_progress.setter
def on_progress(event_hook: Callable[[HashProgressEventParams], 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.

Hash 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.

Hash Config Settings

Base Config Settings

Hash Errors

Hash Errors

	101   Unsupported algorithm.
	104   Cannot read or write file.
	304   Cannot write file.
	305   Cannot read file.