Present single-use password setup handoff

src/user_engine/adapters/provisioning.py

@@ -66,4 +66,9 @@ class HTTPIdentityProvisioningAdapter:
             external_subject=str(result["external_subject"]),
             status=str(result["status"]),
             resumed=bool(result.get("resumed", False)),
+            password_setup_url=(
+                str(result["password_setup_url"])
+                if result.get("password_setup_url")
+                else None
+            ),
         )

src/user_engine/ports.py

@@ -63,6 +63,7 @@ class ProvisioningResult:
     external_subject: str
     status: str
     resumed: bool = False
+    password_setup_url: str | None = None
 
 
 class IdentityProvisioningPort(Protocol):

src/user_engine/web.py

@@ -302,6 +302,14 @@ class PortalApplication:
                     subject=result.external_subject, provider=result.provider,
                     correlation_id=correlation_id,
                 )
+                if result.password_setup_url:
+                    return self._html(
+                        start_response,
+                        self._password_setup_handoff(
+                            result.password_setup_url, tenant
+                        ),
+                        correlation_id,
+                    )
                 query = urlencode({"provisioned": user.user_id, "status": result.status})
                 return self._redirect(start_response, f"/admin/{tenant}?{query}", correlation_id)
             if len(parts) == 6 and parts[3] == "users" and parts[5] == "status":
@@ -481,6 +489,20 @@ class PortalApplication:
             f"<td>{'linked' if directory else 'pending'}</td><td>{action}</td></tr>"
         )
 
+    def _password_setup_handoff(self, setup_url: str, tenant: str) -> str:
+        if not setup_url.startswith("https://"):
+            raise ValidationError("password setup handoff must use HTTPS")
+        return self._page_html(
+            "Password setup",
+            "<h1>Login identity created</h1>"
+            "<p>The password is handled only by the NetKingdom identity "
+            "surface. This short-lived link is single use.</p>"
+            f'<p><a class="button" rel="noreferrer" href="{escape(setup_url)}">'
+            "Continue to password setup</a></p>"
+            f'<p><a href="/admin/{escape(tenant)}">'
+            "Return to tenant administration</a></p>",
+        )
+
     def _redirect(self, start_response: StartResponse, location: str, correlation_id: str) -> list[bytes]:
         start_response("303 See Other", [("Location", location), *self._security_headers(correlation_id)])
         return [b""]

tests/test_provisioning_adapter.py

@@ -20,6 +20,7 @@ class ProvisioningAdapterTests(unittest.TestCase):
             "external_subject": "person-1",
             "status": "password_setup_required",
             "resumed": True,
+            "password_setup_url": "https://kc.example/setup/password?token=opaque",
         }).encode())
         adapter = HTTPIdentityProvisioningAdapter(
             base_url="http://provisioner", bearer_token="secret\n"
@@ -33,6 +34,10 @@ class ProvisioningAdapterTests(unittest.TestCase):
             correlation_id="corr-1",
         ))
         self.assertTrue(result.resumed)
+        self.assertEqual(
+            "https://kc.example/setup/password?token=opaque",
+            result.password_setup_url,
+        )
         request = opener.call_args.args[0]
         self.assertEqual("Bearer secret", request.headers["Authorization"])
         self.assertIn(b"idem-1234567890123456", request.data)

tests/test_web.py

@@ -187,6 +187,17 @@ class PortalApplicationTests(unittest.TestCase):
         self.assertEqual("200 OK", page["status"])
         self.assertIn(b"ada@example.test", html)
         self.assertIn(b"Create login", html)
+        user_id = next(iter(self.app.service.store.users))
+        handoff, html = invoke(
+            self.app,
+            f"/admin/tenant:friendly:binky/users/{user_id}/provision",
+            method="POST",
+            cookie="ue_session=browser",
+            form={"csrf_token": "csrf-test-token"},
+        )
+        self.assertEqual("200 OK", handoff["status"])
+        self.assertIn(b"Continue to password setup", html)
+        self.assertIn(b"https://kc.example/setup/password?token=opaque", html)
 
 
 class FakeProvisioning:
@@ -199,6 +210,7 @@ class FakeProvisioning:
             provider="netkingdom-lldap",
             external_subject=request.primary_email.split("@")[0],
             status="password_setup_required",
+            password_setup_url="https://kc.example/setup/password?token=opaque",
         )
 
     def suspend(self, *, external_subject, idempotency_key, correlation_id):