main.py

from rcncipher import encrypt, decrypt

def text_to_128_bit_hex_chunks(text):
    # Convert text to bytes
    text_bytes = text.encode('utf-8')

    # Calculate the number of 128-bit chunks
    num_chunks = (len(text_bytes) + 15) // 16

    # Pad the text_bytes to make its length a multiple of 16 bytes
    padded_bytes = text_bytes.ljust(num_chunks * 16, b'\0')

    # Divide the padded bytes into 128-bit chunks
    chunks = [padded_bytes[i:i+16] for i in range(0, len(padded_bytes), 16)]

    # Convert each chunk to hexadecimal representation
    hex_chunks = [chunk.hex() for chunk in chunks]
    # print(hex_chunks)
    return hex_chunks

def text_to_hex(text):
    # Convert text to bytes
    text_bytes = text.encode('utf-8')

    # Convert bytes to hexadecimal representation
    hex_representation = text_bytes.hex()

    return hex_representation

def hex_to_text(hex_string):
    # Convert hexadecimal string to bytes
    byte_string = bytes.fromhex(hex_string)

    # Decode bytes to text using UTF-8 encoding
    text = byte_string.decode('utf-8')

    return text
# User input to perform encryption or decryption

while(True):
    choice = input("Enter 'e' for encryption or 'd' for decryption: ")

    if choice == 'e':
        # Get the key and plaintext from the user
        # key = input("Enter the key: ")
        key = text_to_hex(input("Enter the key: "))
        if len(key) <= 32:  # Each hexadecimal character represents 4 bits
            print("Hexadecimal representation:", key)
        else:
            raise ValueError("Hexadecimal representation exceeds 128 bits.")
        plaintext = input("Enter the plaintext: ")

        # Convert the plaintext into 128-bit chunks
        chunks = text_to_128_bit_hex_chunks(plaintext)
        # Encrypt each 128-bit chunk
        ciphertext = ''.join(encrypt(chunk, key) for chunk in chunks)

        print("Ciphertext:", ciphertext)
        # break
    elif choice == 'd':
        # Get the key and ciphertext from the user
        key = text_to_hex(input("Enter the key: "))
        if len(key) <= 32:  # Each hexadecimal character represents 4 bits
            print("Hexadecimal representation:", key)
        else:
            raise ValueError("Hexadecimal representation exceeds 128 bits.")
        ciphertext = input("Enter the ciphertext: ")

        # Decrypt the ciphertext
        decrypted_chunks = [hex_to_text(decrypt(ciphertext[i:i+32], key)) for i in range(0, len(ciphertext), 32)]

        # Remove the padding and convert the decrypted chunks to text
        decrypted_text = ''.join(decrypted_chunks)

        print("Decrypted text:", decrypted_text)
    elif choice == 'exit':	
        break
    else:
        choice = input("Invalid choice. Type exit to, well, exit. Enter 'e' for encryption or 'd' for decryption: ")
        continue