How To Xor Bytes In Python

by

In this blog post, we will explore how to XOR bytes in Python. XOR (Exclusive OR) is a bitwise operator that returns 1 if the bits being compared are different, and 0 if they are the same. In Python, we can perform XOR operation on bytes using the ^ operator.

Method 1: Using a for loop

The first method to xor bytes in Python is by using a for loop. This method is useful when you have two byte sequences of equal length and you want to XOR them element by element. Here’s how you can do it:

def xor_bytes(bytes1, bytes2):
    result = bytearray()
    for b1, b2 in zip(bytes1, bytes2):
        result.append(b1 ^ b2)
    return result

# Example usage:
bytes1 = b'\x01\x02\x03'
bytes2 = b'\x02\x03\x01'
result = xor_bytes(bytes1, bytes2)
print(result)

The xor_bytes function takes two byte sequences as input, and iterates over them using a for loop. It appends the XOR result of the corresponding elements to a new bytearray, which is returned as the final output.

Method 2: Using a list comprehension

The second method to xor bytes in Python is by using a list comprehension. This is a more concise way to achieve the same result as the previous method. Here’s the code:

def xor_bytes(bytes1, bytes2):
    return bytearray([b1 ^ b2 for b1, b2 in zip(bytes1, bytes2)])

# Example usage:
bytes1 = b'\x01\x02\x03'
bytes2 = b'\x02\x03\x01'
result = xor_bytes(bytes1, bytes2)
print(result)

This method uses a list comprehension to generate a list of XOR results, which is then passed to the bytearray constructor to create the final output.

Method 3: XOR with a single byte

If you want to XOR a byte sequence with a single byte, you can modify the previous methods slightly. Here’s how you can do it:

def xor_bytes_with_single_byte(bytes_input, single_byte):
    return bytearray([b ^ single_byte for b in bytes_input])

# Example usage:
bytes_input = b'\x01\x02\x03'
single_byte = 0x02
result = xor_bytes_with_single_byte(bytes_input, single_byte)
print(result)

The xor_bytes_with_single_byte function takes a byte sequence and a single byte as input, and iterates over the byte sequence using a list comprehension. It appends the XOR result of each element with the single byte to a new bytearray, which is returned as the final output.

Conclusion

In this blog post, we have explored different methods to XOR bytes in Python using for loop, list comprehension, and XOR with a single byte. You can choose the method that best suits your needs and use it in your projects. Happy coding!