Getting status code 102 from coinnest.co.kr

Question

I'm trying to write a Python wrapper for a cryptocurrency exchange.

#!/usr/bin/python2.7
import hashlib
import hmac
import time

base_url = 'https://api.coinnest.co.kr'

class Coinnest():
def __init__(self, key, secret):
    self.key = key
    self.secret = secret

def get_balance(self):
    url = base_url + '/api/account/balance'
    nonce = str(int(time.time())*1000)
    key = hashlib.md5(self.secret).hexdigest()
    message = 'key={}&nonce={}'.format(self.key, nonce)
    signature = hmac.new(key, message, hashlib.sha256).hexdigest()
    payload = {'key': key, 'nonce': nonce, 'signature': signature}
    r = requests.post(url, data=payload)
    return r.json()

coinnest = Coinnest('','')
print coinnest.get_order_history()

Response: u'status': 102, u'msg': u'', u'data': u''

According to the API response description: Code 102 means

Parameter error. Required parameters are missing or in wrong format.

I believe I have all the required parameters of

1. key
2. nonce
3. signature.

Am I delivering the payload in the wrong location or in the wrong format? Unfortunately, their documentation is not very clear and I am a beginner.

Thank you.

Answer 1

The docs are terrible, but it looks like you should be signing your message with md5(secret), and set key to your public key, which is different from md5(secret).

from collections import OrderedDict
key = self.key
secret_md5 = hashlib.md5(self.secret).hexdigest()
signature = hmac.new(secret_md5, message, hashlib.sha256).hexdigest()
payload = OrderedDict([('key', key), ('nonce', nonce), ('signature', signature)])

I also recommend using an ordered dict to enforce parameter order.