def message_encrypt():
    encrypted_lines = ""

    # 读取 DES 密钥
    with open('sandbox_sender/desPassword.txt', 'r') as des_password_gotcha:
        des_pwd = des_password_gotcha.readline().strip()  # 移除可能存在的换行符

    # 确保 DES 密钥长度为 8 字节
    if len(des_pwd) != 8:
        raise ValueError("DES 密钥长度必须是 8 字节")

    # 读取原始消息
    with open('sandbox_sender/sample.txt', 'r') as original_file:
        original = original_file.read()

    # 使用 PKCS#7 填充，使文本长度为 DES 块大小的倍数 (8 字节)
    original_length = len(original)
    if original_length % 8 != 0:
        padding_length = 8 - (original_length % 8)
        original = original + chr(padding_length) * padding_length

    # 创建 DES 加密器
    des_cipher = DES.new(des_pwd.encode(), DES.MODE_ECB)  # 使用 ECB 模式

    # 加密文本
    encrypted_lines = ""
    for i in range(0, len(original), 8):
        block = original[i:i + 8].encode()  # 取每个 8 字节块
        encrypted_block = des_cipher.encrypt(block)  # 加密块
        encrypted_lines += encrypted_block.hex()  # 将加密结果转换为十六进制字符串

    # 将加密后的消息保存到文件
    with open('outbox/encrypted_msg.txt', 'w') as container_of_encrypted_contents:
        container_of_encrypted_contents.write(encrypted_lines)
        print("Message has been encrypted.")