From ab91e69e039ffcf87cf52eeb2a61db6d09964843 Mon Sep 17 00:00:00 2001
From: Drishti <54718742+drishti1@users.noreply.github.com>
Date: Mon, 19 Oct 2020 23:42:13 +0530
Subject: [PATCH] Create Drishti

---
 Drishti | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Drishti

diff --git a/Drishti b/Drishti
new file mode 100644
index 0000000..539dc01
--- /dev/null
+++ b/Drishti
@@ -0,0 +1,103 @@
+pip install pyjwt
+
+import jwt
+
+headers = {
+   'kid': settings.SOCIAL_AUTH_APPLE_KEY_ID
+}
+
+payload = {
+   'iss': settings.SOCIAL_AUTH_APPLE_TEAM_ID,
+   'iat': timezone.now(),
+   'exp': timezone.now() + timedelta(days=180),
+   'aud': 'https://appleid.apple.com',
+   'sub': settings.CLIENT_ID,
+}
+
+client_secret = jwt.encode(
+   payload, 
+   settings.SOCIAL_AUTH_APPLE_PRIVATE_KEY, 
+   algorithm='ES256', 
+   headers=headers
+).decode("utf-8")
+decoded = jwt.decode(id_token, '', verify=False)
+
+import jwt
+import requests
+from datetime import timedelta
+from django.conf import settings
+from django.utils import timezone
+from social_core.backends.oauth import BaseOAuth2
+from social_core.utils import handle_http_errors
+
+
+class AppleOAuth2(BaseOAuth2):
+    """apple authentication backend"""
+
+    name = 'apple'
+    ACCESS_TOKEN_URL = 'https://appleid.apple.com/auth/token'
+    SCOPE_SEPARATOR = ','
+    ID_KEY = 'uid'
+
+    @handle_http_errors
+    def do_auth(self, access_token, *args, **kwargs):
+        """
+        Finish the auth process once the access_token was retrieved
+        Get the email from ID token received from apple
+        """
+        response_data = {}
+        client_id, client_secret = self.get_key_and_secret()
+
+        headers = {'content-type': "application/x-www-form-urlencoded"}
+        data = {
+            'client_id': client_id,
+            'client_secret': client_secret,
+            'code': access_token,
+            'grant_type': 'authorization_code',
+            'redirect_uri': 'https://example-app.com/redirect'
+        }
+
+        res = requests.post(AppleOAuth2.ACCESS_TOKEN_URL, data=data, headers=headers)
+        response_dict = res.json()
+        id_token = response_dict.get('id_token', None)
+
+        if id_token:
+            decoded = jwt.decode(id_token, '', verify=False)
+            response_data.update({'email': decoded['email']}) if 'email' in decoded else None
+            response_data.update({'uid': decoded['sub']}) if 'sub' in decoded else None
+
+        response = kwargs.get('response') or {}
+        response.update(response_data)
+        response.update({'access_token': access_token}) if 'access_token' not in response else None
+
+        kwargs.update({'response': response, 'backend': self})
+        return self.strategy.authenticate(*args, **kwargs)
+
+    def get_user_details(self, response):
+        email = response.get('email', None)
+        details = {
+            'email': email,
+        }
+        return details
+
+    def get_key_and_secret(self):
+        headers = {
+            'kid': settings.SOCIAL_AUTH_APPLE_KEY_ID
+        }
+
+        payload = {
+            'iss': settings.SOCIAL_AUTH_APPLE_TEAM_ID,
+            'iat': timezone.now(),
+            'exp': timezone.now() + timedelta(days=180),
+            'aud': 'https://appleid.apple.com',
+            'sub': settings.CLIENT_ID,
+        }
+
+        client_secret = jwt.encode(
+            payload, 
+            settings.SOCIAL_AUTH_APPLE_PRIVATE_KEY, 
+            algorithm='ES256', 
+            headers=headers
+        ).decode("utf-8")
+        
+        return settings.CLIENT_ID, client_secret