import base64
import binascii
import hashlib
import hmac
import requests
import scrypt
import binascii

def hex2bin(hex):
    return binascii.unhexlify(hex)

logN = 15
r = 8
p = 1

name = 'name'
password = 'password'

salt_response = requests.get('https://keybase.io/_/api/1.0/getsalt.json', params={'email_or_username': name}).json()
salt = salt_response['salt']
csrf_token = salt_response['csrf_token']
login_session = salt_response['login_session']

start = 192
end = start + 32
pwh = scrypt.hash(password, hex2bin(salt), 1 << logN, r, p, end)[start:end]

hmac_pwh = hmac.new(pwh, base64.b64decode(login_session), hashlib.sha512).hexdigest()

login_response = requests.post('https://keybase.io/_/api/1.0/login.json', params={'email_or_username': name, 'csrf_token': csrf_token, 'hmac_pwh': hmac_pwh, 'login_session': login_session})