Adding Support For Back Channel Login

Author: kishore7snehil

auth0/authentication/back_channel_login.py

@@ -0,0 +1,37 @@
+from typing import Any
+
+from .base import AuthenticationBase
+
+
+class BackChannelLogin(AuthenticationBase):
+    """Back-Channel Login endpoint"""
+
+    def back_channel_login(
+        self, binding_message: str, login_hint: str, scope: str, **kwargs
+    ) -> Any:
+        """Send a Back-Channel Login.
+
+        Args:
+             binding_message (str): Human-readable string displayed on both the device calling /bc-authorize and the user’s 
+             authentication device to ensure the user is approves the correct request.
+
+             login_hint (str): String containing information about the user to contact for authentication.
+
+             scope(str): "openid" is a required scope.Multiple scopes are separated 
+             with whitespace.
+
+             **kwargs: Other fields to send along with the PAR.
+
+        Returns:
+            auth_req_id, expires_in, interval
+        """
+        return self.authenticated_post(
+            f"{self.protocol}://{self.domain}/bc-authorize",
+            data={
+                "client_id": self.client_id,
+                "binding_message": binding_message,
+                "login_hint": login_hint,
+                "scope": scope,
+                **kwargs,
+            },
+        )

auth0/authentication/get_token.py

@@ -253,3 +253,27 @@ def passwordless_login(
                 "grant_type": "http://auth0.com/oauth/grant-type/passwordless/otp",
             },
         )
+
+    def backchannel_login(
+        self, auth_req_id: str, grant_type: str = "urn:openid:params:grant-type:ciba",
+    ) -> Any:
+        """Calls /oauth/token endpoint with "urn:openid:params:grant-type:ciba" grant type
+
+        Args:
+            auth_req_id (str): The id received from /bc-authorize
+
+            grant_type (str): Denotes the flow you're using.For Back Channel login
+            use urn:openid:params:grant-type:ciba
+
+        Returns:
+            access_token, id_token
+        """
+
+        return self.authenticated_post(
+            f"{self.protocol}://{self.domain}/oauth/token",
+            data={
+                "client_id": self.client_id,
+                "auth_req_id": auth_req_id,
+                "grant_type": grant_type,
+            },
+        )

auth0/test/authentication/test_back_channel_login.py

@@ -0,0 +1,78 @@
+
+import unittest
+from unittest import mock
+
+import requests
+from ...exceptions import Auth0Error, RateLimitError
+
+from ...authentication.back_channel_login import BackChannelLogin
+
+class TestBackChannelLogin(unittest.TestCase):
+    @mock.patch("auth0.rest.RestClient.post")
+    def test_ciba(self, mock_post):
+        g = BackChannelLogin("my.domain.com", "cid", client_secret="clsec")
+
+        g.back_channel_login(
+            binding_message="This is a binding message",
+            login_hint="{ \"format\": \"iss_sub\", \"iss\": \"https://my.domain.auth0.com/\", \"sub\": \"auth0|[USER ID]\" }",
+            scope="openid",
+        )
+
+        args, kwargs = mock_post.call_args
+
+        self.assertEqual(args[0], "https://my.domain.com/bc-authorize")
+        self.assertEqual(
+            kwargs["data"],
+            {
+                "client_id": "cid",
+                "client_secret": "clsec",
+                "binding_message": "This is a binding message",
+                "login_hint": "{ \"format\": \"iss_sub\", \"iss\": \"https://my.domain.auth0.com/\", \"sub\": \"auth0|[USER ID]\" }",
+                "scope": "openid",
+            },
+        )
+
+    @mock.patch("auth0.rest.RestClient.post")
+    def test_should_require_binding_message(self, mock_post):
+        g = BackChannelLogin("my.domain.com", "cid", client_secret="clsec")
+
+        # Expecting an exception to be raised when binding_message is missing
+        with self.assertRaises(Exception) as context:
+            g.back_channel_login(
+                login_hint='{ "format": "iss_sub", "iss": "https://my.domain.auth0.com/", "sub": "auth0|USER_ID" }',
+                scope="openid",
+            )
+
+        # Assert the error message is correct
+        self.assertIn("missing 1 required positional argument: \'binding_message\'", str(context.exception))
+
+    @mock.patch("auth0.rest.RestClient.post")
+    def test_should_require_login_hint(self, mock_post):
+        g = BackChannelLogin("my.domain.com", "cid", client_secret="clsec")
+
+        # Expecting an exception to be raised when login_hint is missing
+        with self.assertRaises(Exception) as context:
+            g.back_channel_login(
+                binding_message="This is a binding message.",
+                scope="openid",
+            )
+
+        # Assert the error message is correct
+        self.assertIn("missing 1 required positional argument: \'login_hint\'", str(context.exception))
+    
+    @mock.patch("auth0.rest.RestClient.post")
+    def test_should_require_scope(self, mock_post):
+        g = BackChannelLogin("my.domain.com", "cid", client_secret="clsec")
+
+        # Expecting an exception to be raised when scope is missing
+        with self.assertRaises(Exception) as context:
+            g.back_channel_login(
+                binding_message="This is a binding message.",
+                login_hint='{ "format": "iss_sub", "iss": "https://my.domain.auth0.com/", "sub": "auth0|USER_ID" }',
+            )
+
+        # Assert the error message is correct
+        self.assertIn("missing 1 required positional argument: \'scope\'", str(context.exception))
+
+
+

auth0/test/authentication/test_get_token.py

@@ -313,3 +313,25 @@ def test_passwordless_login_with_email(self, mock_post):
                 "scope": "openid",
             },
         )
+
+    @mock.patch("auth0.rest.RestClient.post")
+    def test_backchannel_login(self, mock_post):
+        g = GetToken("my.domain.com", "cid", client_secret="csec")
+
+        g.backchannel_login(
+            auth_req_id="reqid",
+            grant_type="urn:openid:params:grant-type:ciba",
+        )
+
+        args, kwargs = mock_post.call_args
+
+        self.assertEqual(args[0], "https://my.domain.com/oauth/token")
+        self.assertEqual(
+            kwargs["data"],
+            {
+                "client_id": "cid",
+                "client_secret": "csec",
+                "auth_req_id": "reqid",
+                "grant_type": "urn:openid:params:grant-type:ciba",
+            },
+        )