# This file is part of krakenex.
#
# krakenex is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# krakenex is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser
# General Public LICENSE along with krakenex. If not, see
# <http://www.gnu.org/licenses/lgpl-3.0.txt>.
import json
import urllib.request, urllib.parse, urllib.error
# private query nonce
import time
# private query signing
import hashlib
import hmac
import base64
from krakenex import connection
[docs]class API(object):
"""Kraken.com cryptocurrency Exchange API.
"""
[docs] def __init__(self, key = '', secret = '', conn = None):
"""Create an object with authentication information.
:param key: key required to make queries to the API
:type key: str
:param secret: private key used to sign API messages
:type secret: str
:param conn: connection TODO
:type conn: krakenex.Connection
"""
self.key = key
self.secret = secret
self.uri = 'https://api.kraken.com'
self.apiversion = '0'
self.conn = conn
[docs] def load_key(self, path):
"""Load key and secret from file.
:param path: path to keyfile
:type path: str
"""
f = open(path, "r")
self.key = f.readline().strip()
self.secret = f.readline().strip()
[docs] def set_connection(self, conn):
"""Set an existing connection to be used as a default in queries.
:param conn: connection TODO
:type conn: krakenex.Connection
"""
self.conn = conn
[docs] def _query(self, urlpath, req = {}, conn = None, headers = {}):
"""Low-level query handling.
:param urlpath: API URL path sans host
:type urlpath: str
:param req: additional API request parameters
:type req: dict
:param conn: connection TODO
:type conn: krakenex.Connection
:param headers: HTTPS headers
:type headers: dict
"""
url = self.uri + urlpath
if conn is None:
if self.conn is None:
conn = connection.Connection()
else:
conn = self.conn
ret = conn._request(url, req, headers)
return json.loads(ret)
[docs] def query_public(self, method, req = {}, conn = None):
"""API queries that do not require a valid key/secret pair.
:param method: API method name
:type method: str
:param req: additional API request parameters
:type req: dict
:param conn: connection TODO
:type conn: krakenex.Connection
"""
urlpath = '/' + self.apiversion + '/public/' + method
return self._query(urlpath, req, conn)
[docs] def query_private(self, method, req={}, conn = None):
"""API queries that require a valid key/secret pair.
:param method: API method name
:type method: str
:param req: additional API request parameters
:type req: dict
:param conn: connection TODO
:type conn: krakenex.Connection
"""
urlpath = '/' + self.apiversion + '/private/' + method
req['nonce'] = int(1000*time.time())
postdata = urllib.parse.urlencode(req)
# Unicode-objects must be encoded before hashing
encoded = (str(req['nonce']) + postdata).encode()
message = urlpath.encode() + hashlib.sha256(encoded).digest()
signature = hmac.new(base64.b64decode(self.secret),
message, hashlib.sha512)
sigdigest = base64.b64encode(signature.digest())
headers = {
'API-Key': self.key,
'API-Sign': sigdigest.decode()
}
return self._query(urlpath, req, conn, headers)