Add oauth login functionality

Author: melvyn2

steam/webauth.py

@@ -61,7 +61,6 @@
 import six
 import requests
 
-from steam import webapi
 from steam.steamid import SteamID
 from steam.utils.web import make_requests_session, generate_session_id
 from steam.core.crypto import rsa_publickey, pkcs1v15_encrypt
@@ -323,6 +322,57 @@ def _finalize_login(self, login_response):
         self.steam_id = SteamID(data['steamid'])
         self.oauth_token = data['oauth_token']
 
+    def oauth_login(self, oauth_token='', steam_id='', language='english'):
+        if oauth_token:
+            self.oauth_token = oauth_token
+        else:
+            if self.oauth_token:
+                oauth_token = self.oauth_token
+            else:
+                raise LoginIncorrect('token is not specified')
+
+        if steam_id:
+            self.steam_id = SteamID(steam_id)
+        else:
+            if not self.steam_id:
+                raise LoginIncorrect('steam_id is not specified')
+
+        steam_id = self.steam_id.as_64
+
+        data = {
+            'access_token': oauth_token
+        }
+
+        try:
+            resp = self.session.post('https://api.steampowered.com/IMobileAuthService/GetWGToken/v0001', data=data)
+        except requests.exceptions.RequestException as e:
+            raise HTTPError(str(e))
+
+        try:
+            resp_data = resp.json()['response']
+        except json.decoder.JSONDecodeError as e:
+            if 'Please verify your <pre>key=</pre> parameter.' in resp.text:
+                raise LoginIncorrect('invalid token')
+            else:
+                raise WebAuthException('failed to decode response')
+
+        self.session_id = generate_session_id()
+
+        for domain in ['store.steampowered.com', 'help.steampowered.com', 'steamcommunity.com']:
+            self.session.cookies.set('steamid', steam_id, domain=domain)
+            self.session.cookies.set('birthtime', '-3333', domain=domain)
+            self.session.cookies.set('sessionid', self.session_id, domain=domain)
+            self.session.cookies.set('mobileClientVersion', '0 (2.1.3)', domain=domain)
+            self.session.cookies.set('mobileClient', 'android', domain=domain)
+            self.session.cookies.set('steamLogin', str(steam_id) + "%7C%7C" + resp_data['token'], domain=domain)
+            self.session.cookies.set('steamLoginSecure', str(steam_id) + "%7C%7C" + resp_data['token_secure'],
+                                     domain=domain, secure=True)
+            self.session.cookies.set('Steam_Language', language, domain=domain)
+
+        self.logged_on = True
+
+        return self.session
+
 
 class WebAuthException(Exception):
     pass