from chacha20 import *
from os import urandom
from math import log

for rounds in range(0,21,2):
    count = 0
    for _ in range(0xffff):
        key = urandom(32)
        key1 = bytes([rot_left(key[i],1) % 0xff for i in range(len(key))])
        nonce = urandom(8)
        chacha1 = ChaCha20(key,nonce,rounds = rounds)
        chacha2 = ChaCha20(key1,nonce,rounds = rounds)
        s1, s2 = chacha1.retrieve_stream(), chacha2.retrieve_stream()
        if rot_left(s1[0],1) == s2[0]:
            count = count + 1
    try:
        print("With {} rounds: 2^({}), {} positive".format(str(rounds),str(log(count/0xffff)),str(count)))
    except:
        continue