feat: OIDC prompt=create implementation

CHANGES.rst

@@ -3,6 +3,11 @@ All notable changes to this project will be documented in this file.
 The format is based on `Keep a Changelog <https://keepachangelog.com/en/1.0.0/>`_,
 and this project adheres to `Semantic Versioning <https://semver.org/spec/v2.0.0.html>`_.
 
+Added
+*****
+
+- OIDC `prompt=create` support. :issue:`185` :pr:`164`
+
 Fixed
 *****
 
@@ -13,6 +18,7 @@ Fixed
 
 Added
 *****
+
 - ``THEME`` can be a relative path
 
 [0.0.39] - 2023-12-15

canaille/oidc/endpoints.py

@@ -34,6 +34,7 @@
 from .oauth import require_oauth
 from .oauth import RevocationEndpoint
 from .utils import SCOPE_DETAILS
+from .well_known import openid_configuration
 
 
 bp = Blueprint("endpoints", __name__, url_prefix="/oauth")
@@ -54,6 +55,23 @@ def authorize():
     if not client:
         abort(400, "Invalid client.")
 
+    # https://openid.net/specs/openid-connect-prompt-create-1_0.html#name-authorization-request
+    # If the OpenID Provider receives a prompt value that it does
+    # not support (not declared in the prompt_values_supported
+    # metadata field) the OP SHOULD respond with an HTTP 400 (Bad
+    # Request) status code and an error value of invalid_request.
+    # It is RECOMMENDED that the OP return an error_description
+    # value identifying the invalid parameter value.
+    if (
+        request.args.get("prompt")
+        and request.args["prompt"]
+        not in openid_configuration()["prompt_values_supported"]
+    ):
+        return {
+            "error": "invalid_request",
+            "error_description": f"prompt '{request.args['prompt'] }' value is not supported",
+        }, 400
+
     user = current_user()
     requested_scopes = request.args.get("scope", "").split(" ")
     allowed_scopes = client.get_allowed_scope(requested_scopes).split(" ")
@@ -65,6 +83,10 @@ def authorize():
             return jsonify({"error": "login_required"})
 
         session["redirect-after-login"] = request.url
+
+        if request.args.get("prompt") == "create":
+            return redirect(url_for("core.account.join"))
+
         return redirect(url_for("core.auth.login"))
 
     if not user.can_use_oidc:

canaille/oidc/well_known.py

@@ -1,4 +1,5 @@
 from flask import Blueprint
+from flask import current_app
 from flask import g
 from flask import jsonify
 from flask import request
@@ -76,7 +77,8 @@ def openid_configuration():
         ],
         "subject_types_supported": ["pairwise", "public"],
         "id_token_signing_alg_values_supported": ["RS256", "ES256", "HS256"],
-        "prompt_values_supported": ["none"],
+        "prompt_values_supported": ["none"]
+        + (["create"] if current_app.config.get("ENABLE_REGISTRATION") else []),
     }
 
 

doc/specifications.rst

@@ -40,7 +40,7 @@ OpenID Connect
 - ❌ `OpenID Connect Back Channel Logout <https://openid.net/specs/openid-connect-backchannel-1_0.html>`_
 - ❌ `OpenID Connect Back Channel Authentication Flow <https://openid.net/specs/openid-client-initiated-backchannel-authentication-core-1_0.html>`_
 - ❌ `OpenID Connect Core Error Code unmet_authentication_requirements <https://openid.net/specs/openid-connect-unmet-authentication-requirements-1_0.html>`_
-- ❌ `Initiating User Registration via OpenID Connect 1.0 <https://openid.net/specs/openid-connect-prompt-create-1_0.html>`_
+- ✅ `Initiating User Registration via OpenID Connect 1.0 <https://openid.net/specs/openid-connect-prompt-create-1_0.html>`_
 
 Comparison with other providers
 ===============================

tests/core/test_registration.py

@@ -71,6 +71,10 @@ def test_registration_with_email_validation(testclient, backend, smtpd):
         res.form["family_name"] = "newuser"
         res = res.form.submit()
 
+    assert res.flashes == [
+        ("success", "Your account has been created successfully."),
+    ]
+
     user = models.User.get()
     assert user
     user.delete()

tests/oidc/test_authorization_prompt.py

@@ -2,11 +2,14 @@
 Tests the behavior of Canaille depending on the OIDC 'prompt' parameter.
 https://openid.net/specs/openid-connect-core-1_0.html#AuthorizationEndpoint
 """
+import datetime
 import uuid
 from urllib.parse import parse_qs
 from urllib.parse import urlsplit
 
 from canaille.app import models
+from canaille.core.account import RegistrationPayload
+from flask import url_for
 
 
 def test_prompt_none(testclient, logged_user, client):
@@ -98,3 +101,125 @@ def test_prompt_no_consent(testclient, logged_user, client):
         status=200,
     )
     assert "consent_required" == res.json.get("error")
+
+
+def test_prompt_create_logged(testclient, logged_user, client):
+    """
+    If prompt=create and user is already logged in,
+    then go straight to the consent page.
+    """
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+
+    consent = models.Consent(
+        consent_id=str(uuid.uuid4()),
+        client=client,
+        subject=logged_user,
+        scope=["openid", "profile"],
+    )
+    consent.save()
+
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+        status=302,
+    )
+    assert res.location.startswith(client.redirect_uris[0])
+
+    consent.delete()
+
+
+def test_prompt_create_registration_disabled(testclient, trusted_client, smtpd):
+    """
+    If prompt=create but Canaille registration is disabled,
+    an error response should be returned.
+
+         If the OpenID Provider receives a prompt value that it does
+         not support (not declared in the prompt_values_supported
+         metadata field) the OP SHOULD respond with an HTTP 400 (Bad
+         Request) status code and an error value of invalid_request.
+         It is RECOMMENDED that the OP return an error_description
+         value identifying the invalid parameter value.
+    """
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=trusted_client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+        status=400,
+    )
+    assert res.json == {
+        "error": "invalid_request",
+        "error_description": "prompt 'create' value is not supported",
+    }
+
+
+def test_prompt_create_not_logged(testclient, trusted_client, smtpd):
+    """
+    If prompt=create and user is not logged in,
+    then display the registration form.
+    Check that the user is correctly redirected to
+    the client page after the registration process.
+    """
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+
+    res = testclient.get(
+        "/oauth/authorize",
+        params=dict(
+            response_type="code",
+            client_id=trusted_client.client_id,
+            scope="openid profile",
+            nonce="somenonce",
+            prompt="create",
+        ),
+    )
+
+    # Display the registration form
+    res = res.follow()
+    res.form["email"] = "[email protected]"
+    res = res.form.submit()
+
+    # Checks the registration mail is sent
+    assert len(smtpd.messages) == 1
+
+    # Simulate a click on the validation link in the mail
+    payload = RegistrationPayload(
+        creation_date_isoformat=datetime.datetime.now(
+            datetime.timezone.utc
+        ).isoformat(),
+        user_name="",
+        user_name_editable=True,
+        email="[email protected]",
+        groups=[],
+    )
+    registration_url = url_for(
+        "core.account.registration",
+        data=payload.b64(),
+        hash=payload.build_hash(),
+        _external=True,
+    )
+
+    # Fill the user creation form
+    res = testclient.get(registration_url)
+    res.form["user_name"] = "newuser"
+    res.form["password1"] = "password"
+    res.form["password2"] = "password"
+    res.form["family_name"] = "newuser"
+    res = res.form.submit()
+
+    assert res.flashes == [
+        ("success", "Your account has been created successfully."),
+    ]
+
+    # Return to the client
+    res = res.follow()
+    assert res.location.startswith(trusted_client.redirect_uris[0])

tests/oidc/test_well_known.py

@@ -100,3 +100,9 @@ def test_openid_configuration(testclient):
         "userinfo_endpoint": "http://canaille.test/oauth/userinfo",
         "prompt_values_supported": ["none"],
     }
+
+
+def test_openid_configuration_prompt_value_create(testclient):
+    testclient.app.config["ENABLE_REGISTRATION"] = True
+    res = testclient.get("/.well-known/openid-configuration", status=200).json
+    assert "create" in res["prompt_values_supported"]