auth_chain.py 文件源码

def server_udp_post_decrypt(self, buf):
        mac_key = self.server_info.key
        md5data = hmac.new(mac_key, buf[-8:-5], self.hashfunc).digest()
        uid = struct.unpack('<I', buf[-5:-1])[0] ^ struct.unpack('<I', md5data[:4])[0]
        uid = struct.pack('<I', uid)
        if uid in self.server_info.users:
            user_key = self.server_info.users[uid]
        else:
            uid = None
            if not self.server_info.users:
                user_key = self.server_info.key
            else:
                user_key = self.server_info.recv_iv
        if hmac.new(user_key, buf[:-1], self.hashfunc).digest()[:1] != buf[-1:]:
            return (b'', None)
        rand_len = self.udp_rnd_data_len(md5data, self.random_client)
        encryptor = encrypt.Encryptor(to_bytes(base64.b64encode(user_key)) + to_bytes(base64.b64encode(md5data)), 'rc4')
        out_buf = encryptor.decrypt(buf[:-8 - rand_len])
        return (out_buf, uid)