Added at_hash when access token is present

This is required by response type "id_token token", but can be
used by other flows if they choose.

oidc_provider/lib/endpoints/authorize.py

@@ -121,35 +121,41 @@ class AuthorizeEndpoint(object):
                 query_params['state'] = self.params.state if self.params.state else ''
 
             elif self.grant_type == 'implicit':
-                # We don't need id_token if it's an OAuth2 request.
-                if self.is_authentication:
-                    id_token_dic = create_id_token(
-                        user=self.request.user,
-                        aud=self.client.client_id,
-                        nonce=self.params.nonce,
-                        request=self.request)
-                    query_fragment['id_token'] = encode_id_token(id_token_dic, self.client)
-                else:
-                    id_token_dic = {}
-
                 token = create_token(
                     user=self.request.user,
                     client=self.client,
-                    id_token_dic=id_token_dic,
                     scope=self.params.scope)
 
-                # Store the token.
-                token.save()
-
-                query_fragment['token_type'] = 'bearer'
-                # TODO: Create setting 'OIDC_TOKEN_EXPIRE'.
-                query_fragment['expires_in'] = 60 * 10
-
                 # Check if response_type is an OpenID request with value 'id_token token'
                 # or it's an OAuth2 Implicit Flow request.
                 if self.params.response_type in ['id_token token', 'token']:
                     query_fragment['access_token'] = token.access_token
 
+                # We don't need id_token if it's an OAuth2 request.
+                if self.is_authentication:
+                    kwargs = {
+                        "user": self.request.user,
+                        "aud": self.client.client_id,
+                        "nonce": self.params.nonce,
+                        "request": self.request
+                    }
+                    # Include at_hash when access_token is being returned.
+                    if 'access_token' in query_fragment:
+                        kwargs['at_hash'] = token.at_hash
+                    id_token_dic = create_id_token(**kwargs)
+                    query_fragment['id_token'] = encode_id_token(id_token_dic, self.client)
+                    token.id_token = id_token_dic
+                else:
+                    id_token_dic = {}
+
+                # Store the token.
+                token.id_token = id_token_dic
+                token.save()
+
+                query_fragment['token_type'] = 'bearer'
+                # TODO: Create setting 'OIDC_TOKEN_EXPIRE'.
+                query_fragment['expires_in'] = 60 * 10
+
                 query_fragment['state'] = self.params.state if self.params.state else ''
 
         except Exception as error:

oidc_provider/lib/endpoints/token.py

@@ -131,23 +131,24 @@ class TokenEndpoint(object):
             return self.create_refresh_response_dic()
 
     def create_code_response_dic(self):
+        token = create_token(
+            user=self.code.user,
+            client=self.code.client,
+            scope=self.code.scope)
+
         if self.code.is_authentication:
             id_token_dic = create_id_token(
                 user=self.code.user,
                 aud=self.client.client_id,
                 nonce=self.code.nonce,
+                at_hash=token.at_hash,
                 request=self.request,
             )
         else:
             id_token_dic = {}
 
-        token = create_token(
-            user=self.code.user,
-            client=self.code.client,
-            id_token_dic=id_token_dic,
-            scope=self.code.scope)
-
         # Store the token.
+        token.id_token = id_token_dic
         token.save()
 
         # We don't need to store the code anymore.
@@ -164,24 +165,25 @@ class TokenEndpoint(object):
         return dic
 
     def create_refresh_response_dic(self):
+        token = create_token(
+            user=self.token.user,
+            client=self.token.client,
+            scope=self.token.scope)
+
         # If the Token has an id_token it's an Authentication request.
         if self.token.id_token:
             id_token_dic = create_id_token(
                 user=self.token.user,
                 aud=self.client.client_id,
                 nonce=None,
+                at_hash=token.at_hash,
                 request=self.request,
             )
         else:
             id_token_dic = {}
 
-        token = create_token(
-            user=self.token.user,
-            client=self.token.client,
-            id_token_dic=id_token_dic,
-            scope=self.token.scope)
-
         # Store the token.
+        token.id_token = id_token_dic
         token.save()
 
         # Forget the old token.

oidc_provider/lib/utils/token.py

@@ -13,7 +13,7 @@ from oidc_provider.models import *
 from oidc_provider import settings
 
 
-def create_id_token(user, aud, nonce, request=None):
+def create_id_token(user, aud, nonce, at_hash=None, request=None):
     """
     Receives a user object and aud (audience).
     Then creates the id_token dictionary.
@@ -44,6 +44,9 @@ def create_id_token(user, aud, nonce, request=None):
     if nonce:
         dic['nonce'] = str(nonce)
 
+    if at_hash:
+        dic['at_hash'] = at_hash
+
     processing_hook = settings.get('OIDC_IDTOKEN_PROCESSING_HOOK')
 
     if isinstance(processing_hook, (list, tuple)):
@@ -73,13 +76,13 @@ def encode_id_token(payload, client):
         keys = [SYMKey(key=client.client_secret, alg=alg)]
     else:
         raise Exception('Unsupported key algorithm.')
-    
+
     _jws = JWS(payload, alg=alg)
 
     return _jws.sign_compact(keys)
 
 
-def create_token(user, client, id_token_dic, scope):
+def create_token(user, client, scope, id_token_dic=None):
     """
     Create and populate a Token object.
 
@@ -90,7 +93,8 @@ def create_token(user, client, id_token_dic, scope):
     token.client = client
     token.access_token = uuid.uuid4().hex
 
-    token.id_token = id_token_dic
+    if id_token_dic is not None:
+        token.id_token = id_token_dic
 
     token.refresh_token = uuid.uuid4().hex
     token.expires_at = timezone.now() + timedelta(
@@ -112,7 +116,7 @@ def create_code(user, client, scope, nonce, is_authentication,
     code.client = client
 
     code.code = uuid.uuid4().hex
-    
+
     if code_challenge and code_challenge_method:
         code.code_challenge = code_challenge
         code.code_challenge_method = code_challenge_method

oidc_provider/models.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
-from hashlib import md5
+import base64
+import binascii
+from hashlib import md5, sha256
 import json
 
 from django.db import models
@@ -117,6 +119,18 @@ class Token(BaseCodeTokenModel):
         verbose_name = _(u'Token')
         verbose_name_plural = _(u'Tokens')
 
+    @property
+    def at_hash(self):
+        # @@@ d-o-p only supports 256 bits (change this if that changes)
+        hashed_access_token = sha256(
+            self.access_token.encode('ascii')
+        ).hexdigest().encode('ascii')
+        return base64.urlsafe_b64encode(
+            binascii.unhexlify(
+                hashed_access_token[:len(hashed_access_token) // 2]
+            )
+        ).rstrip(b'=').decode('ascii')
+
 
 class UserConsent(BaseCodeTokenModel):