的Python 3哈希HMAC-SHA512

Question

我正在寫https://poloniex.com/support/api/

公共方法都做工精細一個機器人，但交易API方法需要一些額外的技巧：

All calls to the trading API are sent via HTTP POST to https://poloniex.com/tradingApi and must contain the following headers:
Key - Your API key.
Sign - The query's POST data signed by your key's "secret" according to the HMAC-SHA512 method.
Additionally, all queries must include a "nonce" POST parameter. The nonce parameter is an integer which must always be greater than the previous nonce used.
All responses from the trading API are in JSON format.

我對returnBalances長相碼像這樣：

import hashlib 
import hmac 
from time import time 

import requests 


class Poloniex: 
    def __init__(self, APIKey, Secret): 
     self.APIKey = APIKey 
     self.Secret = Secret 

    def returnBalances(self): 
     url = 'https://poloniex.com/tradingApi' 
     payload = { 
      'command': 'returnBalances', 
      'nonce': int(time() * 1000), 
     } 

     headers = { 
      'Key': self.APIKey, 
      'Sign': hmac.new(self.Secret, payload, hashlib.sha512).hexdigest(), 
     } 

     r = requests.post(url, headers=headers, data=payload) 
     return r.json() 

trading.py：

APIkey = 'AAA-BBB-CCC' 
secret = b'123abc' 

polo = Poloniex(APIkey, secret) 
print(polo.returnBalances()) 

而且我得到了以下錯誤：

Traceback (most recent call last): 
    File "C:/Python/Poloniex/trading.py", line 5, in <module> 
    print(polo.returnBalances()) 
    File "C:\Python\Poloniex\poloniex.py", line 22, in returnBalances 
    'Sign': hmac.new(self.Secret, payload, hashlib.sha512).hexdigest(), 
    File "C:\Users\Balazs91\AppData\Local\Programs\Python\Python35-32\lib\hmac.py", line 144, in new 
    return HMAC(key, msg, digestmod) 
    File "C:\Users\Balazs91\AppData\Local\Programs\Python\Python35-32\lib\hmac.py", line 84, in __init__ 
    self.update(msg) 
    File "C:\Users\Balazs91\AppData\Local\Programs\Python\Python35-32\lib\hmac.py", line 93, in update 
    self.inner.update(msg) 
TypeError: object supporting the buffer API required 

Process finished with exit code 1 

我也試圖執行以下，但它並沒有幫助： https://stackoverflow.com/a/25111089/7317891

任何幫助，不勝感激！

Answer 1

您傳遞給requests.post的有效載荷必須是有效的查詢字符串或與該查詢字符串對應的字典。通常情況下，傳遞字典並獲取請求爲您構建查詢字符串會更方便，但在這種情況下，我們需要從查詢字符串構造HMAC簽名，因此我們使用標準的urlib.parse模塊構建查詢串。

令人煩惱的是，urlib.parse.urlencode函數返回一個文本字符串，所以我們需要將它編碼爲一個字節字符串，以便讓它可以接受hashlib。使用UTF-8的明顯編碼方式是：編碼一個只包含純ASCII的文本字符串，因爲UTF-8會創建一個與等效的Python 2字符串相同的字節序列（當然，urlencode只會返回純ASCII），所以此代碼的行爲與鏈接的Poloniex API頁面上的舊Python 2代碼行爲相同。

from time import time 
import urllib.parse 
import hashlib 
import hmac 

APIkey = b'AAA-BBB-CCC' 
secret = b'123abc' 

payload = { 
    'command': 'returnBalances', 
    'nonce': int(time() * 1000), 
} 

paybytes = urllib.parse.urlencode(payload).encode('utf8') 
print(paybytes) 

sign = hmac.new(secret, paybytes, hashlib.sha512).hexdigest() 
print(sign) 

輸出

b'command=returnBalances&nonce=1492868800766' 
3cd1630522382abc13f24b78138f30983c9b35614ece329a5abf4b8955429afe7d121ffee14b3c8c042fdaa7a0870102f9fb0b753ab793c084b1ad6a3553ea71 

然後你就可以這樣做

headers = { 
    'Key': APIKey, 
    'Sign': sign, 
} 

r = requests.post(url, headers=headers, data=paybytes)