import hmac

import hashlib

import time

import base64

from requests.auth import AuthBase

class CBProAuth(AuthBase):

# Provided by CBPro: https://docs.pro.coinbase.com/#signing-a-message

def __init__(self, api_key, secret_key, passphrase):

self.api_key = api_key

self.secret_key = secret_key

self.passphrase = passphrase

def __call__(self, request):

timestamp = str(time.time())

message = ''.join([timestamp, request.method,

request.path_url, (request.body or '')])

request.headers.update(get_auth_headers(timestamp, message,

self.api_key,

self.secret_key,

self.passphrase))

return request

def get_auth_headers(timestamp, message, api_key, secret_key, passphrase):

message = message.encode('ascii')

hmac_key = base64.b64decode(secret_key)

signature = hmac.new(hmac_key, message, hashlib.sha256)

signature_b64 = base64.b64encode(signature.digest()).decode('utf-8')

return {

'Content-Type': 'Application/JSON',

'CB-ACCESS-SIGN': signature_b64,

'CB-ACCESS-TIMESTAMP': timestamp,

'CB-ACCESS-KEY': api_key,

'CB-ACCESS-PASSPHRASE': passphrase

}