Add CSRF-safe tenant identity administration

src/user_engine/web.py

@@ -15,7 +15,7 @@ from html import escape
 import json
 import secrets
 from typing import Any, Callable, Iterable, Mapping
-from urllib.parse import parse_qs
+from urllib.parse import parse_qs, urlencode
 
 from user_engine.domain import AccountStatus
 from user_engine.errors import AuthorizationDenied, ConflictError, NotFoundError, ValidationError
@@ -68,6 +68,14 @@ class PortalApplication:
             return self._dispatch(environ, start_response, str(correlation_id))
         except (ValidationError, ConflictError, ValueError) as exc:
             return self._error(start_response, "400 Bad Request", "invalid_request", str(exc), correlation_id)
+        except RuntimeError:
+            return self._error(
+                start_response,
+                "502 Bad Gateway",
+                "provisioning_unavailable",
+                "Identity provisioning is temporarily unavailable.",
+                correlation_id,
+            )
         except AuthorizationDenied:
             return self._error(start_response, "403 Forbidden", "access_denied", "Access denied.", correlation_id)
         except NotFoundError:
@@ -211,23 +219,143 @@ class PortalApplication:
                     )
                 ),
             ))
-            return self._json(start_response, "200 OK", _jsonable(result), correlation_id)
+            identity = self.service.link_identity(
+                actor,
+                user.user_id,
+                issuer="urn:netkingdom:directory",
+                subject=result.external_subject,
+                provider=result.provider,
+                correlation_id=correlation_id,
+            )
+            return self._json(start_response, "200 OK", {
+                "provisioning": _jsonable(result),
+                "identity": _jsonable(identity),
+            }, correlation_id)
         if path.startswith("/api/v1/tenants/") and "/users/" in path and method == "PATCH":
             parts = path.split("/")
             tenant, user_id = parts[4], parts[6]
             body = self._body(environ)
             status = AccountStatus(str(body["status"]))
-            result = self.service.set_tenant_account_status(
-                actor, user_id, status, tenant=tenant, correlation_id=correlation_id
+            idempotency_key = str(environ.get("HTTP_IDEMPOTENCY_KEY", ""))
+            if len(idempotency_key) < 16:
+                raise ValidationError("Idempotency-Key must contain at least 16 characters")
+            result = self._change_status(
+                actor, tenant, user_id, status,
+                idempotency_key=idempotency_key,
+                correlation_id=correlation_id,
             )
             return self._json(start_response, "200 OK", _jsonable(result), correlation_id)
         if path.startswith("/admin/") and method == "GET":
             tenant = path.split("/")[2]
             self.service.resolve_tenant_context(actor, tenant)
             memberships = self.service.store.memberships_for_tenant(tenant)
-            return self._html(start_response, self._admin(tenant, memberships), correlation_id)
+            return self._html(
+                start_response,
+                self._admin(tenant, memberships, self._csrf_token(environ)),
+                correlation_id,
+            )
+        if path.startswith("/admin/") and method == "POST":
+            parts = path.split("/")
+            tenant = parts[2]
+            self.service.resolve_tenant_context(actor, tenant)
+            body = self._form_body(environ)
+            self._require_csrf(environ, str(body.get("csrf_token", "")))
+            if len(parts) == 4 and parts[3] == "users":
+                user = self.service.create_user(
+                    actor,
+                    display_name=body.get("display_name"),
+                    primary_email=body.get("primary_email"),
+                    correlation_id=correlation_id,
+                )
+                self.service.set_tenant_account_status(
+                    actor, user.user_id, AccountStatus.ACTIVE,
+                    tenant=tenant, correlation_id=correlation_id,
+                )
+                self.service.add_membership(
+                    actor, user.user_id, tenant=tenant, scope_type="tenant",
+                    scope_id=tenant, kind=str(body.get("role", "user")),
+                    correlation_id=correlation_id,
+                )
+                return self._redirect(start_response, f"/admin/{tenant}", correlation_id)
+            if len(parts) == 6 and parts[3] == "users" and parts[5] == "provision":
+                if self.provisioning is None:
+                    raise ValidationError("identity provisioning is unavailable")
+                user_id = parts[4]
+                user = self.service.store.user(user_id)
+                if user is None:
+                    raise NotFoundError("user not found")
+                result = self.provisioning.provision(ProvisioningRequest(
+                    user_id=user.user_id,
+                    tenant=tenant,
+                    primary_email=user.primary_email,
+                    display_name=user.display_name,
+                    idempotency_key=f"portal-{user.user_id}-{tenant}",
+                    correlation_id=correlation_id,
+                    roles=tuple(
+                        item.kind for item in self.service.store.memberships_for_user(
+                            user.user_id, tenant=tenant
+                        )
+                    ),
+                ))
+                self.service.link_identity(
+                    actor, user.user_id, issuer="urn:netkingdom:directory",
+                    subject=result.external_subject, provider=result.provider,
+                    correlation_id=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":
+                status = AccountStatus(str(body.get("status", "")))
+                if status not in {AccountStatus.ACTIVE, AccountStatus.SUSPENDED}:
+                    raise ValidationError("browser lifecycle supports active or suspended")
+                self._change_status(
+                    actor, tenant, parts[4], status,
+                    idempotency_key=f"portal-status-{parts[4]}-{status.value}",
+                    correlation_id=correlation_id,
+                )
+                return self._redirect(start_response, f"/admin/{tenant}", correlation_id)
         return self._error(start_response, "404 Not Found", "not_found", "Resource not found.", correlation_id)
 
+    def _change_status(
+        self,
+        actor: Any,
+        tenant: str,
+        user_id: str,
+        status: AccountStatus,
+        *,
+        idempotency_key: str,
+        correlation_id: str,
+    ) -> Any:
+        if self.provisioning is None:
+            raise ValidationError("identity provisioning is unavailable")
+        self.service.resolve_tenant_context(actor, tenant)
+        identity = next(
+            (
+                item for item in self.service.store.identities_for_user(user_id)
+                if item.provider == "netkingdom-lldap"
+            ),
+            None,
+        )
+        if identity is None:
+            raise ValidationError("user has no managed login identity")
+        if status == AccountStatus.SUSPENDED:
+            self.provisioning.suspend(
+                external_subject=identity.subject,
+                idempotency_key=idempotency_key,
+                correlation_id=correlation_id,
+            )
+        elif status == AccountStatus.ACTIVE:
+            self.provisioning.reactivate(
+                external_subject=identity.subject,
+                idempotency_key=idempotency_key,
+                correlation_id=correlation_id,
+            )
+        else:
+            raise ValidationError("provider lifecycle supports active or suspended")
+        return self.service.set_tenant_account_status(
+            actor, user_id, status, tenant=tenant, correlation_id=correlation_id
+        )
+
     def _claims(self, environ: Mapping[str, Any]) -> Mapping[str, Any]:
         if self.oidc_client is not None:
             session_id = cookie_value(str(environ.get("HTTP_COOKIE", "")), "ue_session")
@@ -264,6 +392,29 @@ class PortalApplication:
             raise ValidationError("request body must be an object")
         return value
 
+    @staticmethod
+    def _form_body(environ: Mapping[str, Any]) -> Mapping[str, str]:
+        content_type = str(environ.get("CONTENT_TYPE", "")).partition(";")[0]
+        if content_type != "application/x-www-form-urlencoded":
+            raise ValidationError("form content type is required")
+        length = min(int(environ.get("CONTENT_LENGTH") or 0), 65536)
+        payload = environ["wsgi.input"].read(length).decode("utf-8")
+        return {key: values[0] for key, values in parse_qs(payload).items()}
+
+    def _csrf_token(self, environ: Mapping[str, Any]) -> str:
+        if self.oidc_client is None:
+            raise AuthorizationDenied("browser session required")
+        session_id = cookie_value(str(environ.get("HTTP_COOKIE", "")), "ue_session")
+        token = self.oidc_client.csrf_token(session_id or "")
+        if token is None:
+            raise AuthorizationDenied("browser session required")
+        return token
+
+    def _require_csrf(self, environ: Mapping[str, Any], supplied: str) -> None:
+        expected = self._csrf_token(environ)
+        if not supplied or not secrets.compare_digest(supplied, expected):
+            raise AuthorizationDenied("invalid CSRF token")
+
     @staticmethod
     def _page(environ: Mapping[str, Any]) -> tuple[int, int]:
         query = parse_qs(str(environ.get("QUERY_STRING", "")))
@@ -284,16 +435,56 @@ class PortalApplication:
             + identity,
         )
 
-    def _admin(self, tenant: str, memberships: tuple[Any, ...]) -> str:
+    def _admin(self, tenant: str, memberships: tuple[Any, ...], csrf_token: str) -> str:
         rows = "".join(
-            f"<tr><td>{escape(item.user_id)}</td><td>{escape(item.kind)}</td><td>{escape(item.scope_id)}</td></tr>"
+            self._admin_row(tenant, item, csrf_token)
             for item in memberships
-        ) or '<tr><td colspan="3">No members yet.</td></tr>'
+        ) or '<tr><td colspan="6">No members yet.</td></tr>'
         return self._page_html(
             f"{tenant} users",
-            f"<h1>{escape(tenant)} users</h1><table><thead><tr><th>User</th><th>Role</th><th>Scope</th></tr></thead><tbody>{rows}</tbody></table>",
+            f"""<h1>{escape(tenant)} users</h1>
+<section><h2>Add a user</h2>
+<form method="post" action="/admin/{escape(tenant)}/users">
+<input type="hidden" name="csrf_token" value="{escape(csrf_token)}">
+<label>Display name <input name="display_name" required autocomplete="name"></label>
+<label>Email <input name="primary_email" type="email" required autocomplete="email"></label>
+<label>Role <select name="role"><option value="user">User</option><option value="tenant-admin">Tenant administrator</option></select></label>
+<button type="submit">Add user</button></form></section>
+<section><h2>Members</h2><table><thead><tr><th>User</th><th>Email</th><th>Role</th><th>Status</th><th>Directory</th><th>Action</th></tr></thead><tbody>{rows}</tbody></table></section>""",
         )
 
+    def _admin_row(self, tenant: str, membership: Any, csrf_token: str) -> str:
+        user = self.service.store.user(membership.user_id)
+        identities = self.service.store.identities_for_user(membership.user_id)
+        directory = next(
+            (item for item in identities if item.provider == "netkingdom-lldap"),
+            None,
+        )
+        tenant_account = self.service.store.tenant_account(tenant, membership.user_id)
+        status = tenant_account.status if tenant_account else AccountStatus.INVITED
+        action = (
+            f"""<span>Linked as {escape(directory.subject)}</span>
+<form method="post" action="/admin/{escape(tenant)}/users/{escape(membership.user_id)}/status">
+<input type="hidden" name="csrf_token" value="{escape(csrf_token)}">
+<input type="hidden" name="status" value="{'active' if status == AccountStatus.SUSPENDED else 'suspended'}">
+<button type="submit">{'Reactivate' if status == AccountStatus.SUSPENDED else 'Suspend'}</button></form>"""
+            if directory
+            else f"""<form method="post" action="/admin/{escape(tenant)}/users/{escape(membership.user_id)}/provision">
+<input type="hidden" name="csrf_token" value="{escape(csrf_token)}">
+<button type="submit">Create login</button></form>"""
+        )
+        return (
+            f"<tr><td>{escape(user.display_name or membership.user_id) if user else escape(membership.user_id)}</td>"
+            f"<td>{escape(user.primary_email or '') if user else ''}</td>"
+            f"<td>{escape(membership.kind)}</td>"
+            f"<td>{escape(status.value)}</td>"
+            f"<td>{'linked' if directory else 'pending'}</td><td>{action}</td></tr>"
+        )
+
+    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""]
+
     @staticmethod
     def _page_html(title: str, body: str) -> str:
         return f"""<!doctype html><html lang="en"><head><meta charset="utf-8">
@@ -305,7 +496,9 @@ header,main{{max-width:68rem;margin:auto;padding:1.25rem}}header{{border-bottom:
 h1{{font:clamp(2.2rem,7vw,5.5rem)/.98 Georgia,serif;max-width:13ch}}a{{color:var(--accent)}}
 .button{{display:inline-block;background:var(--accent);color:white;padding:.8rem 1.15rem;border-radius:.3rem;text-decoration:none}}
 table{{width:100%;border-collapse:collapse;background:#fff}}th,td{{padding:.75rem;text-align:left;border-bottom:1px solid var(--line)}}
-a:focus-visible{{outline:3px solid #e59f24;outline-offset:3px}}@media(max-width:640px){{body{{font-size:16px}}}}
+section{{margin:2rem 0}}form{{display:grid;gap:.8rem;max-width:42rem}}label{{display:grid;gap:.25rem}}
+input,select,button{{font:inherit;padding:.65rem}}button{{background:var(--accent);color:white;border:0;border-radius:.3rem;cursor:pointer}}
+a:focus-visible,input:focus-visible,select:focus-visible,button:focus-visible{{outline:3px solid #e59f24;outline-offset:3px}}@media(max-width:640px){{body{{font-size:16px}}table{{display:block;overflow-x:auto}}}}
 </style></head><body><header><strong>Railiance identity</strong></header><main>{body}</main></body></html>"""
 
     def _html(self, start_response: StartResponse, body: str, correlation_id: str) -> list[bytes]: