Salsa20 Class

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The Salsa20 class can be used to encrypt and decrypt data with the XSalsa20 and Salsa20 algorithm.

Syntax

class ipworksencrypt.Salsa20

Remarks

The class implements XSalsa20 as well as Salsa20. The algorithm property specifies which algorithm to use when encrypting and decryption. In addition the 12 and 8 round variants of Salsa20 are supported.

Data may be encrypted and decrypted in its entirety by calling encrypt and decrypt or chunk by chunk by calling encrypt_block and decrypt_block.

In all operations a key and iv must be used. If iv is not set one is automatically generated. key_password may be set in order to automatically generate both a key and iv when a method is called. The same key_password, or key and iv pair are used on both sides of the operation data can be encrypted and decrypted.

Encrypt Notes

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

• iv (required)
• key (required)

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.

Additional Notes

The key property must be set to a 256 bit (32 byte) value. This is the only allowed value for ChaCha20. If key_password is set both key and iv will be automatically generated when encrypt is called.

The iv must be set to a 192 bit (24 byte) value when algorithm is set to XSalsa. The iv must be set to a 64 bit (8 byte) value when algorithm is set to Salsa.

If iv is not set a value will automatically be generated by the class when encrypt is called.

During encryption the on_progress event will fire as data is encrypted.

Encrypt Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; salsa.InputMessage = "hello salsa!"; salsa.Encrypt(); //salsa.OutputMessageB contains the byte[] of the encrypted data. The above code produces the following encrypted bytes. // { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }

Encrypt Block Notes

encrypt_block will encrypt the input data and return the encrypted block. The encrypted block will always be the same length as the decrypted data. The following properties are applicable:

• iv (required)
• key (required)

InputBuffer specifies the input data to encrypt.

EncryptBlock Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; byte[] tempEncryptedBlock; //Encrypt any number of blocks of any size tempEncryptedBlock = salsa.EncryptBlock(part1); tempEncryptedBlock = salsa.EncryptBlock(part2);

Decrypt Notes

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

• iv (required)
• key (required)

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.

Additional Notes

The key property must be set to the 256 bit (32 byte) value originally used to encrypt the data. iv must be set to the original IV value used to encrypt the data.

If using a password, key_password must be set to the same key_password used when encrypting the data. This will automatically generate both key and iv when decrypt is called.

During decryption the on_progress event will fire as data is decrypted.

Decrypt Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; salsa.InputMessageB = new byte[] { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }; salsa.Decrypt(); Console.WriteLine(salsa.OutputMessage); //outputs "hello salsa!"

Decrypt Block Notes

decrypt_block will decrypt the input data and return the decrypted block. The decrypted block will always be the same length as the encrypted data. The following properties are applicable:

• iv (required)
• key (required)

InputBuffer specifies the input data to decrypt.

DecryptBlock Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; byte[] tempDecryptedBlock; //Decrypt any number of blocks of any size tempDecryptedBlock = salsa.DecryptBlock(part1); tempDecryptedBlock = salsa.DecryptBlock(part2);

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 Salsa20 algorithm.

Syntax

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

algorithm = property(get_algorithm, set_algorithm)

Default Value

1

Remarks

This property specifies the Salsa implementation to use. Possible values are:

• 0 (Salsa20)
• 1 (XSalsa20 - default)

The XSalsa20 algorithm is recommended and generally to be considered more secure. The Salsa20 algorithm is fully supported for implementations that require this. In addition the reduced 12 and 8 round variants of Salsa20 are also supported, please see SalsaRounds for details.

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). This is also referred to as the nonce. 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.

XSalsa Notes:

When Algorithm is set to XSalsa the length of the IV must be 192 bits in length (24 bytes).

Salsa Notes:

When Algorithm is set to Salsa the length of the IV must be 64 bits in length (8 bytes).

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. This key must be 256 bits in length (32 bytes).

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

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.

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:

• 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.

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:

• 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.

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

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

• iv (required)
• key (required)

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.

Additional Notes

The key property must be set to the 256 bit (32 byte) value originally used to encrypt the data. iv must be set to the original IV value used to encrypt the data.

If using a password, key_password must be set to the same key_password used when encrypting the data. This will automatically generate both key and iv when decrypt is called.

During decryption the on_progress event will fire as data is decrypted.

Decrypt Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; salsa.InputMessageB = new byte[] { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }; salsa.Decrypt(); Console.WriteLine(salsa.OutputMessage); //outputs "hello salsa!"

decrypt_block Method

Decrypts a block and returns the decrypted data.

Syntax

def decrypt_block(input_buffer: bytes) -> bytes: ...

Remarks

decrypt_block will decrypt the input data and return the decrypted block. The decrypted block will always be the same length as the encrypted data. The following properties are applicable:

• iv (required)
• key (required)

InputBuffer specifies the input data to decrypt.

DecryptBlock Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; byte[] tempDecryptedBlock; //Decrypt any number of blocks of any size tempDecryptedBlock = salsa.DecryptBlock(part1); tempDecryptedBlock = salsa.DecryptBlock(part2);

encrypt Method

Encrypts the data.

Syntax

def encrypt() -> None: ...

Remarks

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

• iv (required)
• key (required)

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.

Additional Notes

The key property must be set to a 256 bit (32 byte) value. This is the only allowed value for ChaCha20. If key_password is set both key and iv will be automatically generated when encrypt is called.

The iv must be set to a 192 bit (24 byte) value when algorithm is set to XSalsa. The iv must be set to a 64 bit (8 byte) value when algorithm is set to Salsa.

If iv is not set a value will automatically be generated by the class when encrypt is called.

During encryption the on_progress event will fire as data is encrypted.

Encrypt Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; salsa.InputMessage = "hello salsa!"; salsa.Encrypt(); //salsa.OutputMessageB contains the byte[] of the encrypted data. The above code produces the following encrypted bytes. // { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }

encrypt_block Method

Encrypts data and returns the encrypted block.

Syntax

def encrypt_block(input_buffer: bytes) -> bytes: ...

Remarks

encrypt_block will encrypt the input data and return the encrypted block. The encrypted block will always be the same length as the decrypted data. The following properties are applicable:

• iv (required)
• key (required)

InputBuffer specifies the input data to encrypt.

EncryptBlock Example

Salsa20 salsa = new Salsa20(); //32 Bytes salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 }; //24 Bytes salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 }; byte[] tempEncryptedBlock; //Encrypt any number of blocks of any size tempEncryptedBlock = salsa.EncryptBlock(part1); tempEncryptedBlock = salsa.EncryptBlock(part2);

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 Salsa20ErrorEventParams(object):
  @property
  def error_code() -> int: ...

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

# In class Salsa20:
@property
def on_error() -> Callable[[Salsa20ErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[Salsa20ErrorEventParams], 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 Salsa20ProgressEventParams(object):
  @property
  def bytes_processed() -> int: ...

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

# In class Salsa20:
@property
def on_progress() -> Callable[[Salsa20ProgressEventParams], None]: ...
@on_progress.setter
def on_progress(event_hook: Callable[[Salsa20ProgressEventParams], 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.

Salsa20 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.

XSalsa20 Config Settings

Base Config Settings

Salsa20 Errors

XSalsa20 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.
	130   Invalid number of rounds. The number of rounds used when algorithm is set to Salsa must be 8, 12, or 20.