OAuth 2.0简单实战（以新浪开发平台为例）

背景

本人去年在UCLA打酱油的时候曾经要求抓过新浪微博的有关数据。然而要读写这些微博信息和朋友关系，必须要在新浪围脖平台上注册应用。也就是要接触

OAuth 2.0

这个东西。当时基本不懂，今天看到了阮一峰博客上的这篇文章,决定自己动手一试。

准备

首先，你要把阮一峰博客上的这篇文章 粗略的读一遍。

然后你要上 新浪开发平台 注册一个应用，我注册的是微连接 - 网页应用



打开界面你可以看到App Key和App Secret，这是要用的东西

好，接下来下载新浪微博python SDK，我们用

Python

进行分析

分析

首先，我们先根据微博API上面的HOW-TO 文档上来做

from weibo import APIClient

APP_KEY = '1234567' # app key
APP_SECRET = 'abcdefghijklmn' # app secret
CALLBACK_URL = 'http://www.example.com/callback'
client = APIClient(app_key=APP_KEY, app_secret=APP_SECRET, redirect_uri=CALLBACK_URL)
url = client.get_authorize_url()

这样就拿到了URL了，你打开这个URL一看，正是提示你要授权应用（出现

error:redirect_uri_mismatch

同学请到新浪微博开发界面填好

redirect_uri

)

好，我们看看源码

class APIClient(object):
'''
API client using synchronized invocation.
'''
def __init__(self, app_key, app_secret, redirect_uri=None, response_type='code', domain='api.weibo.com', version='2'):
self.client_id = str(app_key)
self.client_secret = str(app_secret)
self.redirect_uri = redirect_uri
self.response_type = response_type
self.auth_url = 'https://%s/oauth2/' % domain
self.api_url = 'https://%s/%s/' % (domain, version)
self.access_token = None
self.expires = 0.0
self.get = HttpObject(self, _HTTP_GET)
self.post = HttpObject(self, _HTTP_POST)
self.upload = HttpObject(self, _HTTP_UPLOAD)

def get_authorize_url(self, redirect_uri=None, **kw):
'''
return the authorization url that the user should be redirected to.
'''
redirect = redirect_uri if redirect_uri else self.redirect_uri
if not redirect:
raise APIError('21305', 'Parameter absent: redirect_uri', 'OAuth2 request')
response_type = kw.pop('response_type', 'code')
return '%s%s?%s' % (self.auth_url, 'authorize', \
_encode_params(client_id = self.client_id, \
response_type = response_type, \
redirect_uri = redirect, **kw))

client_id

,

redirect_url

,

app_key

，好熟悉啊，仔细一看，原来是授权码模式的第一步

The client constructs the request URI by adding the following

parameters to the query component of the authorization endpoint URI

using the "application/x-www-form-urlencoded" format, per Appendix B:

response_type

REQUIRED. Value MUST be set to "code".

client_id

REQUIRED. The client identifier as described in Section 2.2.

redirect_uri

OPTIONAL. As described in Section 3.1.2.

scope

OPTIONAL. The scope of the access request as described by

Section 3.3.

state

RECOMMENDED. An opaque value used by the client to maintain

state between the request and callback. The authorization

server includes this value when redirecting the user-agent back

to the client. The parameter SHOULD be used for preventing

cross-site request forgery as described in Section 10.12.

好了，当我们把账号密码填写好了之后验证成功后，你发现你的浏览器上面的URL发生了变化，到底是这么回事呢，请看第二步Authorization Response

If the resource owner grants the access request, the authorization

server issues an authorization code and delivers it to the client by

adding the following parameters to the query component of the

redirection URI using the "application/x-www-form-urlencoded" format,

per Appendix B:

code

REQUIRED. The authorization code generated by the

authorization server. The authorization code MUST expire

shortly after it is issued to mitigate the risk of leaks. A

maximum authorization code lifetime of 10 minutes is

RECOMMENDED. The client MUST NOT use the authorization code more than once. If an authorization code is used more than

once, the authorization server MUST deny the request and SHOULD

revoke (when possible) all tokens previously issued based on

that authorization code. The authorization code is bound to

the client identifier and redirection URI.

state

REQUIRED if the "state" parameter was present in the client

authorization request. The exact value received from the

client.

For example, the authorization server redirects the user-agent by

sending the following HTTP response:

HTTP/1.1 302 Found
Location: https://client.example.com/cb?code=SplxlOBeZQQYbYS6WxSbIA &state=xyz

然后我们继续按照API的指示做

# 获取URL参数code:
code = your.web.framework.request.get('code')
r = client.request_access_token(code)

def request_access_token(self, code, redirect_uri=None):
redirect = redirect_uri if redirect_uri else self.redirect_uri
if not redirect:
raise APIError('21305', 'Parameter absent: redirect_uri', 'OAuth2 request')
r = _http_post('%s%s' % (self.auth_url, 'access_token'), \
client_id = self.client_id, \
client_secret = self.client_secret, \
redirect_uri = redirect, \
code = code, grant_type = 'authorization_code')
return self._parse_access_token(r)

这个获得

code

方法通常可以有很多，但是我们既然是实验，就手动复制

code

吧。

哈哈，很明显

request_access_token

这个方法就是发一个

HTTP POST

包嘛

第三步Access Token Request

The client makes a request to the token endpoint by sending the

following parameters using the "application/x-www-form-urlencoded"

format per Appendix B with a character encoding of UTF-8 in the HTTP

request entity-body:

grant_type

REQUIRED. Value MUST be set to "authorization_code".

code

REQUIRED. The authorization code received from the

authorization server.

redirect_uri

REQUIRED, if the "redirect_uri" parameter was included in the

authorization request as described in Section 4.1.1, and their

values MUST be identical.

client_id

REQUIRED, if the client is not authenticating with the

authorization server as described in Section 3.2.1.

If the client type is confidential or the client was issued client

credentials (or assigned other authentication requirements), the

client MUST authenticate with the authorization server as described

in Section 3.2.1.

For example, the client makes the following HTTP request using TLS

(with extra line breaks for display purposes only):

POST /token HTTP/1.1
Host: server.example.com
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code&code=SplxlOBeZQQYbYS6WxSbIA
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb

最后一步

access_token = r.access_token # 新浪返回的token，类似abc123xyz456
expires_in = r.expires_in # token过期的UNIX时间：http://zh.
4000
wikipedia.org/wiki/UNIX%E6%97%B6%E9%97%B4
# TODO: 在此可保存access token
client.set_access_token(access_token, expires_in)

就是从服务器返回的

HTTP

包中解析

access_token

和

expire_in

数据

同样来看

RFC

文档中写的

If the access token request is valid and authorized, the

authorization server issues an access token and optional refresh

token as described in Section 5.1. If the request client

authentication failed or is invalid, the authorization server returns

an error response as described in Section 5.2.

An example successful response:

HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache

{
"access_token":"2YotnFZFEjr1zCsicMWpAA",
"token_type":"example",
"expires_in":3600,
"refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA",
"example_parameter":"example_value"
}

接下来就可以调用API啦~

对于最后两步看的很累的话，可以自己尝试写一个

import urllib, urllib2

APP_KEY = '2613134348'
APP_SECRET = '5a14f41598a7444c7e0dc0422519b091' # app secret
ACCESS_TOKEN = '9cd1b3869e62491331caf444456953e8'
data = {
'grant_type' : 'authorization_code',
'code' :ACCESS_TOKEN,
'redirect_uri':'http://www.ceclinux.org',
'client_id':APP_KEY,
'client_secret':APP_SECRET
}
headers = {'host':'api.weibo.com','Authorization':'OAuth2 %s' % ACCESS_TOKEN}
data = urllib.urlencode(data)
request = urllib2.Request('https://api.weibo.com/oauth2/access_token', data, headers)
response = urllib2.urlopen(request)
print response.read()

运行这个文件

最后也能得到一个包含

access_token

和

expire_date

的JSON文件

没了～

参考

http://github.liaoxuefeng.com/sinaweibopy/ https://github.com/michaelliao/sinaweibopy/wiki/OAuth2-HOWTO http://www.ruanyifeng.com/blog/2014/05/oauth_2_0.html