问题
I'm trying to hash an API secret using hmac. But I can't get it to work using Python 3.5.
Here's the problem code:
sign = hmac.new(self.Secret, post_data, hashlib.sha512).hexdigest()
Here's the error:
TypeError: key: expected bytes or bytearray, but got 'str'
I've tried encoding first like so...
secret = b'api_secret_here'
Also tried...
sign = hmac.new(self.Secret.encode('utf-8'), post_data, hashlib.sha512).hexdigest()
and...
sign = hmac.new(self.Secret.encode(), post_data, hashlib.sha512).hexdigest()
All give the error:
TypeError: Unicode-objects must be encoded before hashing
Here's the code in full context:
import hashlib
import hmac
import json
import sys
import time
from datetime import datetime
# Tested on Python 2.7.6 & 3.4.3
if sys.version_info[0] == 3:
from urllib.request import Request, urlopen
from urllib.parse import urlencode
else:
from urllib2 import Request, urlopen
from urllib import urlencode
minute = 60
hour = minute * 60
day = hour * 24
week = day * 7
month = day * 30
year = day * 365
# Possible Commands
PUBLIC_COMMANDS = ['returnTicker', 'return24hVolume', 'returnOrderBook', 'returnTradeHistory', 'returnChartData',
'returnCurrencies', 'returnLoanOrders']
PRIVATE_COMMANDS = ['returnBalances', 'returnCompleteBalances', 'returnDepositAddresses', 'generateNewAddress',
'returnDepositsWithdrawals', 'returnOpenOrders', 'returnTradeHistory',
'returnAvailableAccountBalances', 'returnTradableBalances', 'returnOpenLoanOffers',
'returnActiveLoans', 'createLoanOffer', 'cancelLoanOffer', 'toggleAutoRenew', 'buy', 'sell',
'cancelOrder', 'moveOrder', 'withdraw', 'transferBalance', 'returnMarginAccountSummary',
'marginBuy', 'marginSell', 'getMarginPosition', 'closeMarginPosition']
class Poloniex:
def __init__(self, APIKey='', Secret=''):
self.APIKey = APIKey
self.Secret = Secret
# Conversions
self.timestamp_str = lambda timestamp=time.time(), format="%Y-%m-%d %H:%M:%S": datetime.fromtimestamp(
timestamp).strftime(format)
self.str_timestamp = lambda datestr=self.timestamp_str(), format="%Y-%m-%d %H:%M:%S": int(
time.mktime(time.strptime(datestr, format)))
self.float_roundPercent = lambda floatN, decimalP=2: str(round(float(floatN) * 100, decimalP)) + "%"
# PUBLIC COMMANDS
self.marketTicker = lambda x=0: self.api('returnTicker')
self.marketVolume = lambda x=0: self.api('return24hVolume')
self.marketStatus = lambda x=0: self.api('returnCurrencies')
self.marketLoans = lambda coin: self.api('returnLoanOrders', {'currency': coin})
self.marketOrders = lambda pair='all': self.api('returnOrderBook', {'currencyPair': pair})
self.marketChart = lambda pair, period=day, start=time.time() - (month * 2), end=time.time(): self.api(
'returnChartData', {'currencyPair': pair, 'period': period, 'start': start, 'end': end})
self.marketTradeHist = lambda pair: self.api('returnTradeHistory',
{'currencyPair': pair}) # NEEDS TO BE FIXED ON Poloniex
# PRIVATE COMMANDS
# self.myTradeHist = lambda pair: self.api('returnTradeHistory',{'currencyPair':pair})
self.myAvailBalances = lambda x=0: self.api('returnAvailableAccountBalances')
self.myMarginAccountSummary = lambda x=0: self.api('returnMarginAccountSummary')
self.myMarginPosition = lambda pair='all': self.api('getMarginPosition', {'currencyPair': pair})
self.myCompleteBalances = lambda x=0: self.api('returnCompleteBalances')
self.myAddresses = lambda x=0: self.api('returnDepositAddresses')
self.myOrders = lambda pair='all': self.api('returnOpenOrders', {'currencyPair': pair})
self.myDepositsWithdraws = lambda x=0: self.api('returnDepositsWithdrawals')
self.myTradeableBalances = lambda x=0: self.api('returnTradableBalances')
self.myActiveLoans = lambda x=0: self.api('returnActiveLoans')
self.myOpenLoanOrders = lambda x=0: self.api('returnOpenLoanOffers')
## Trading functions ##
self.createLoanOrder = lambda coin, amount, rate: self.api('createLoanOffer',
{'currency': coin, 'amount': amount, 'duration': 2,
'autoRenew': 0, 'lendingRate': rate})
self.cancelLoanOrder = lambda orderId: self.api('cancelLoanOffer', {'orderNumber': orderId})
self.toggleAutoRenew = lambda orderId: self.api('toggleAutoRenew', {'orderNumber': orderId})
self.closeMarginPosition = lambda pair: self.api('closeMarginPosition', {'currencyPair': pair})
self.marginBuy = lambda pair, rate, amount, lendingRate=2: self.api('marginBuy',
{'currencyPair': pair, 'rate': rate,
'amount': amount,
'lendingRate': lendingRate})
self.marginSell = lambda pair, rate, amount, lendingRate=2: self.api('marginSell',
{'currencyPair': pair, 'rate': rate,
'amount': amount,
'lendingRate': lendingRate})
self.buy = lambda pair, rate, amount: self.api('buy', {'currencyPair': pair, 'rate': rate, 'amount': amount})
self.sell = lambda pair, rate, amount: self.api('sell', {'currencyPair': pair, 'rate': rate, 'amount': amount})
self.cancelOrder = lambda orderId: self.api('cancelOrder', {'orderNumber': orderId})
self.moveOrder = lambda orderId, rate, amount: self.api('moveOrder', {'orderNumber': orderId, 'rate': rate,
'amount': amount})
self.withdraw = lambda coin, amount, address: self.api('withdraw',
{'currency': coin, 'amount': amount, 'address': address})
self.transferBalance = lambda coin, amount, fromac, toac: self.api('transferBalance',
{'currency': coin, 'amount': amount,
'fromAccount': fromac, 'toAccount': toac})
#####################
# Main Api Function #
#####################
def api(self, command, args={}):
"""
returns 'False' if invalid command or if no APIKey or Secret is specified (if command is "private")
returns {"error":"<error message>"} if API error
"""
args['command'] = command
if command in PRIVATE_COMMANDS:
if len(self.APIKey) < 2 or len(self.Secret) < 2:
print("An APIKey and Secret is needed!")
return False
url, args['nonce'] = ['https://poloniex.com/tradingApi', int(time.time() * 42)]
post_data = urlencode(args)
sign = hmac.new(self.Secret, post_data, hashlib.sha512).hexdigest()
headers = {'Sign': sign, 'Key': self.APIKey}
ret = urlopen(Request(url, post_data, headers))
return json.loads(ret.read().decode(encoding='UTF-8'))
elif command in PUBLIC_COMMANDS:
url = 'https://poloniex.com/public?'
if not args:
ret = urlopen(Request(url + command))
return json.loads(ret.read().decode(encoding='UTF-8'))
else:
ret = urlopen(Request(url + urlencode(args)))
return json.loads(ret.read().decode(encoding='UTF-8'))
else:
return False
回答1:
Both the key and msg arguments to hmac.new() must be bytes objects. You are feeding it a str object, as that is what the urllib.parse.urlencode() function produces:
Convert [...] to a percent-encoded ASCII text string. If the resultant string is to be used as a data for POST operation with the
urlopen()function, then it should be encoded to bytes, otherwise it would result in aTypeError.
So not only should your self.Secret be bytes, you need to encode the post_data element too, even more so since you'll be passing it to urlopen() for a POST operation:
post_data = urlencode(args).encode('ASCII')
sign = hmac.new(self.Secret, post_data, hashlib.sha512).hexdigest()
headers = {'Sign': sign, 'Key': self.APIKey}
ret = urlopen(Request(url, post_data, headers))
来源：https://stackoverflow.com/questions/36261697/hmac-hashing-error-in-python-3-5