Python的HMAC散列值编码为base64

Question

我试图做一个Twitter的权威性和Django中间件的帮助下，我在那里计算这样的请求的签名（https://dev.twitter.com/oauth/overview/creating-signatures）：

key = b"MY_KEY&" 
    raw_init = "POST" + "&" + quote("https://api.twitter.com/1.1/oauth/request_token", safe='') 

    raw_params = <some_params> 
    raw_params = quote(raw_params, safe='') 

    #byte encoding for HMAC, otherwise it returns "expected bytes or bytearray, but got 'str'" 
    raw_final = bytes(raw_init + "&" + raw_params, encoding='utf-8') 

    hashed = hmac.new(key, raw_final, sha1) 

    request.raw_final = hashed 

    # here are my problems: I need a base64 encoded string, but get the error "'bytes' object has no attribute 'encode'" 
    request.auth_header = hashed.digest().encode("base64").rstrip('\n') 

正如你所看到的，没有办法base64编码一个'字节'对象。

提出的解决方案在这里：Implementaion HMAC-SHA1 in python

Answer 1

诀窍是用base64模块，而不是直接的STR /字节编码，它支持二进制。

你可以这样适合它（未经测试你的背景下，应工作）：

import base64 
#byte encoding for HMAC, otherwise it returns "expected bytes or bytearray, but got 'str'" 
raw_final = bytes(raw_init + "&" + raw_params, encoding='utf-8') 

hashed = hmac.new(key, raw_final, sha1) 

request.raw_final = hashed 

# here directly use base64 module, and since it returns bytes, just decode it 
request.auth_header = base64.b64encode(hashed.digest()).decode() 

出于测试目的，找到一个独立的下面，工作示例（Python 3兼容，巨蟒2.x的用户都创建bytes字符串时删除 “ASCII” 参数）：

from hashlib import sha1 
import hmac 
import base64 

# key = CONSUMER_SECRET& #If you dont have a token yet 
key = bytes("CONSUMER_SECRET&TOKEN_SECRET","ascii") 


# The Base String as specified here: 
raw = bytes("BASE_STRING","ascii") # as specified by oauth 

hashed = hmac.new(key, raw, sha1) 

print(base64.b64encode(hashed.digest()).decode()) 

结果：

Rh3xUffks487KzXXTc3n7+Hna6o= 

PS：您所提供的答案已经不只有Python 3下它的蟒蛇2工作。