des_PurePy.des module

Module providing a DES class for a DES implementation

class des_PurePy.des.DES(key)

Bases: object

Implements the Data Encryption Standard (DES).

A DES object is initialized with a 64-bit key and can be used repeatedly to encrypt or decrypt data.

Parameters:

key (str or bytes) – The DES key. May be given as a hexadecimal string (with or without a 0x prefix) or as a bytes object.

Methods

decrypt(ciphertext)	Decrypts the input ciphertext by key according to DES
encrypt(plaintext)	Encrypts the input plaintext by key according to DES

decrypt(ciphertext) → str

Decrypts the input ciphertext by key according to DES

Parameters:

ciphertext (hex string or bytes object) – Ciphertext to be encrypted. Can be a string representing a hex number or a bytes object. Hex strings can have a leading ‘0x’ and are case-insensitive. ciphertext length should be a multiple of the block size (64 bits)

Returns:

cleartext – Decrypted cleartext as a hex number. Has a leading ‘0x’.

Return type:

str

encrypt(plaintext) → str

Encrypts the input plaintext by key according to DES

Parameters:

plaintext (hex string or bytes object) – Plaintext to be encrypted. Can be a string representing a hex number or a bytes object. Hex strings can have a leading ‘0x’ and are case-insensitive. plaintext can be any length.

Returns:

ciphertext – Encrypted ciphertext as a hex number. Has a leading ‘0x’. Length can vary according to length of input. Will always be a multiple of the block size.

Return type:

str

key

Key to be used for encrypting or decrypting. Can be a string representing a hex number or a bytes object. Hex strings can have a leading ‘0x’ and are case-insensitive. key should be exactly the key size for DES (64 bits)