@xterm said:
Guys I found the encryted file and the encryptor, But I really dont know how to decrypt.Please give me some hints
First check what encryption cipher is used. Let’s just pretend for now the cipher is a symmetric cipher. In that case the secret to encrypt and decrypt is the same. Some ciphers also need an initilization vector (usually called IV) that gets into the calculation as well an needs to be the same for both the encrypt and decrypt operation too.
Now given you have a let’s say python skeleton where some of the parts of the encryption scheme can be seen, i.e. the encryption part. I‘d first try to find out how the encryption part works by making a fully working example: add needed imports (if you don’t know the libs, just ask Mr. Google), call the functions that are in the skeleton and encrypt a file. Some debug and xxd output of the encrypted file might help understand what data gets written to what part of the encrypted file.
Now work the steps back: Write a decrypt function that gets all parts needed for decrypt function from what you have. Some might be in the encrypted file (i.e. the chunk of ciphered text, …), some might be unknown and might need brute-forcing or guessing/reading what you have 
. Pay attention to what happens to input in the encryptor - some cipher functions need aligned input so sometime the coder just uses some functions that convert user input into aligned output (hash functions come in handy sometimes).
This worked for me although I am not too familiar with the scripting language that was needed here. It is mostly a matter of doing the steps in reverse order.