paperclip/server/src/services/execution-allowlist.ts

104 lines
3.7 KiB
TypeScript

/**
* Pure execution-allowlist guard.
*
* Decides whether a candidate execution environment is permitted to run an
* agent, given the instance-level execution policy. This is security-critical:
* on a shared cloud instance we FORCE all untrusted tenant agents onto the
* Kubernetes sandbox-provider and REFUSE local/in-process execution so that a
* tenant agent can never run inside the server process or on an unsandboxed
* local/ssh adapter.
*
* The merged tree's environment model represents the Kubernetes sandbox as a
* core `driver: "sandbox"` environment whose `config.provider` is the plugin's
* `driverKey` ("kubernetes", `kind: "sandbox_provider"`). The local default is
* `driver: "local"`. This module knows nothing about the DB or heartbeat — it
* just maps (driver, provider, policy) -> allow/deny so it is trivially
* unit-testable.
*/
/** Provider key (== plugin driverKey) of the first-party Kubernetes sandbox provider. */
export const KUBERNETES_PROVIDER_KEY = "kubernetes" as const;
/**
* Instance execution policy as read from instance general settings.
*
* - `"any"` / absent: unrestricted — any environment driver is allowed (the
* default, preserves single-tenant / local-trusted behavior).
* - `"kubernetes"`: force the Kubernetes sandbox provider; deny local, ssh, and
* any non-kubernetes sandbox provider.
*/
export interface ExecutionPolicy {
executionMode?: "kubernetes" | "any";
}
/**
* The minimal shape of the selected/candidate environment the guard needs.
* `driver` is the core `EnvironmentDriver`; `provider` is the sandbox provider
* key (== plugin driverKey) for `driver: "sandbox"` environments, else null.
*/
export interface ExecutionEnvironmentCandidate {
driver: string;
provider: string | null | undefined;
}
export type ExecutionAllowlistDecision =
| { allowed: true }
| {
allowed: false;
reason: string;
deniedDriver: string;
deniedProvider: string | null;
};
/** True when the policy forces all execution onto the Kubernetes sandbox. */
export function isExecutionForcedToKubernetes(policy: ExecutionPolicy | null | undefined): boolean {
return policy?.executionMode === "kubernetes";
}
/**
* True iff the candidate environment is the Kubernetes sandbox provider, i.e. a
* core `sandbox` driver whose provider key is "kubernetes".
*/
export function isKubernetesSandboxEnvironment(
candidate: ExecutionEnvironmentCandidate,
): boolean {
return candidate.driver === "sandbox" && candidate.provider === KUBERNETES_PROVIDER_KEY;
}
/**
* Decide whether the candidate environment may run under the given policy.
*
* When `executionMode === "kubernetes"`, ONLY a `sandbox_provider` driver with
* provider/driverKey "kubernetes" is allowed; a `local` driver (or any non-k8s
* sandbox provider, or ssh, or plugin) is DENIED. Otherwise everything is
* allowed.
*/
export function evaluateExecutionAllowlist(
policy: ExecutionPolicy | null | undefined,
candidate: ExecutionEnvironmentCandidate,
): ExecutionAllowlistDecision {
if (!isExecutionForcedToKubernetes(policy)) {
return { allowed: true };
}
if (isKubernetesSandboxEnvironment(candidate)) {
return { allowed: true };
}
const provider = candidate.provider ?? null;
const target =
candidate.driver === "sandbox"
? `sandbox provider "${provider ?? "(none)"}"`
: `"${candidate.driver}" driver`;
return {
allowed: false,
reason:
`Instance execution policy requires the Kubernetes sandbox provider ` +
`(executionMode=kubernetes), but the resolved environment uses the ${target}. ` +
`Untrusted execution on a non-Kubernetes environment is refused.`,
deniedDriver: candidate.driver,
deniedProvider: provider,
};
}