feat(session): bind readonly task owner access to captured identities

packages/coding-agent/src/session/internal/managed-session-storage.ts

@@ -1474,6 +1474,7 @@ export class ManagedSessionDescendantStore {
 		retained?: { authority: RecoveryFsRoot; authorityBaseDir: string },
 		policy?: ManagedSessionSecurityPolicy,
 		profileAgentDir?: string,
+		expectedSubtreeRoot?: ManagedDirectoryRoot,
 	) {
 		managedRelativePath(root, baseDir);
 
@@ -1512,13 +1513,46 @@ export class ManagedSessionDescendantStore {
 				});
 			}
 			this.#authority = retained.authority;
+			if (
+				expectedSubtreeRoot &&
+				(expectedSubtreeRoot.canonicalPath !== this.#baseDir ||
+					expectedSubtreeRoot.dev !== this.#subtreeRoot.dev ||
+					expectedSubtreeRoot.ino !== this.#subtreeRoot.ino)
+			)
+				throw new Error("Managed subtree authority changed during establishment");
 			this.#assertBound();
 
 			return;
 		}
 		assertManagedDirectoryRoot(root);
-		ensureManagedDirectory(this.#baseDir, root, this.#policy);
+		if (expectedSubtreeRoot) {
+			if (expectedSubtreeRoot.canonicalPath !== this.#baseDir)
+				throw new Error("Managed subtree authority path mismatch");
+			assertManagedDirectoryRoot(expectedSubtreeRoot);
+			const verified = validateNativeSecurityResult(
+				process.platform === "win32"
+					? nativeSessionStorage().verifyOwnerOnlyPathSecurityExpected(
+							this.#baseDir,
+							"directory",
+							expectedSubtreeRoot.dev,
+							expectedSubtreeRoot.ino,
+						)
+					: nativeSessionStorage().verifyOwnerOnlyPathSecurity(this.#baseDir, "directory"),
+				"verify",
+				"directory",
+			);
+			if (!verified.ok) throw securityError(this.#baseDir, verified);
+			assertManagedDirectoryRoot(expectedSubtreeRoot);
+		} else {
+			ensureManagedDirectory(this.#baseDir, root, this.#policy);
+		}
 		const subtreeStat = fs.lstatSync(this.#baseDir, { bigint: true });
+		if (
+			expectedSubtreeRoot &&
+			(canonicalFileId(subtreeStat.dev) !== expectedSubtreeRoot.dev ||
+				canonicalFileId(subtreeStat.ino) !== expectedSubtreeRoot.ino)
+		)
+			throw new Error("Managed subtree authority changed during establishment");
 		this.#subtreeRoot = Object.freeze({
 			canonicalPath: this.#baseDir,
 			dev: canonicalFileId(subtreeStat.dev),
@@ -1634,6 +1668,50 @@ export class ManagedSessionDescendantStore {
 		}
 		this.#assertBound();
 	}
+
+	/** Capture a directory identity through this store's retained managed root without repairing it. */
+	captureDirectoryIdentity(relativePath: string): { dev: string; ino: string } {
+		this.#assertBound();
+		const resolved = this.#resolve(relativePath);
+		if (!this.#authority) this.#assertPathBackedDirectoryChain(resolved);
+		const named = fs.lstatSync(resolved, { bigint: true });
+		if (!named.isDirectory() || named.isSymbolicLink()) throw new Error("managed_directory_identity_unavailable");
+		const dev = canonicalFileId(named.dev);
+		const ino = canonicalFileId(named.ino);
+		if (dev !== this.#subtreeRoot.dev) throw new Error("managed_directory_identity_unavailable");
+		if (this.#authority) {
+			const retainedRelative = this.#relative(resolved);
+			if (retainedRelative === "") {
+				if (dev !== this.#subtreeRoot.dev || ino !== this.#subtreeRoot.ino)
+					throw new Error("Managed descendant root binding changed");
+			} else {
+				const retained = this.#authority.retainManagedDirectory(retainedRelative, dev.toString(), ino.toString());
+				try {
+					const identity = retained.identity();
+					if (
+						!identity.ok ||
+						!identity.identity ||
+						identity.identity.dev !== dev.toString() ||
+						identity.identity.ino !== ino.toString()
+					)
+						throw new Error(identity.code ?? "managed_directory_identity_unavailable");
+				} finally {
+					retained.close();
+				}
+			}
+		}
+		const after = fs.lstatSync(resolved, { bigint: true });
+		if (
+			!after.isDirectory() ||
+			after.isSymbolicLink() ||
+			canonicalFileId(after.dev) !== dev ||
+			canonicalFileId(after.ino) !== ino
+		)
+			throw new Error("managed_directory_identity_changed");
+		this.#assertBound();
+		return { dev: dev.toString(), ino: ino.toString() };
+	}
+
 	#assertBound(): void {
 		if (!this.#authority) {
 			const named = fs.statSync(this.#baseDir, { bigint: true });
@@ -3019,6 +3097,34 @@ export class ManagedSessionDescendantStore {
 		if (!removed.ok) throw new Error(removed.code ?? "managed_remove_failed");
 		this.#assertBound();
 	}
+
+	/** Remove one exact managed tree through the parent-identity-bound native protocol. */
+	removeTreeExpectedWithParentIdentity(
+		relativePath: string,
+		expected: NativeDirectoryTreeSnapshot,
+		parentIdentity: { dev: bigint; ino: bigint },
+	): NativeExactUnlinkResult {
+		this.#beforeMutation();
+		this.#assertBound();
+		const resolved = this.#resolve(relativePath);
+		const parentPath = path.dirname(resolved);
+		const parentRelative = path.relative(this.#baseDir, parentPath);
+		if (path.isAbsolute(parentRelative) || parentRelative === ".." || parentRelative.startsWith(`..${path.sep}`))
+			throw new Error("managed_remove_parent_outside_store");
+		const currentParent = this.captureDirectoryIdentity(parentRelative);
+		if (
+			currentParent.dev !== canonicalFileId(parentIdentity.dev).toString() ||
+			currentParent.ino !== canonicalFileId(parentIdentity.ino).toString()
+		)
+			throw new Error("managed_remove_parent_identity_mismatch");
+		const removed = nativeSessionStorage().exactRemoveDirectoryTree(resolved, expected, {
+			dev: BigInt(currentParent.dev),
+			ino: BigInt(currentParent.ino),
+		});
+		this.#assertBound();
+		return removed;
+	}
+
 	fsyncTree(): NativeDirectoryTreeSnapshot {
 		this.#beforeMutation();
 		this.#assertBound();

packages/coding-agent/src/session/internal/task-artifact-owner-access.ts

@@ -0,0 +1,229 @@
+import * as fs from "node:fs";
+import * as path from "node:path";
+import type { NativeDirectoryTreeSnapshot } from "@gajae-code/natives";
+import {
+	assertSafeRelativePath,
+	assertSessionRoot,
+	freezeTreeSnapshot,
+	immutableDeletionEvidence,
+	isOwnerRetainedRoot,
+	manifestRelativePath,
+	OWNER_DIRECTORY,
+	OWNER_MANIFEST,
+	OWNER_SCHEMA_VERSION,
+	ownerIdForSession,
+	ownerRelativePath,
+	parseTaskArtifactOwnerLocator,
+	sameOwnerParentIdentity,
+	type TaskArtifactOwnerDeletionEvidence,
+	type TaskArtifactOwnerLocator,
+	type TaskArtifactOwnerParentIdentity,
+	type TaskArtifactOwnerStorageContext,
+} from "../task-artifact-owner-codec";
+import { ManagedSessionDescendantStore } from "./managed-session-storage";
+
+export interface OwnerManifest extends TaskArtifactOwnerLocator {
+	readonly sessionId: string;
+}
+
+export function newSessionRootStore(context: TaskArtifactOwnerStorageContext): ManagedSessionDescendantStore {
+	assertSessionRoot(context);
+	if (path.resolve(context.profileAgentDir) !== context.profileAgentDir)
+		throw new Error("task_artifact_owner_profile_invalid");
+	const profile = fs.lstatSync(context.profileAgentDir, { bigint: true });
+	if (!profile.isDirectory() || profile.isSymbolicLink()) throw new Error("task_artifact_owner_profile_invalid");
+	const stat = fs.lstatSync(context.sessionsRoot, { bigint: true });
+	if (!stat.isDirectory() || stat.isSymbolicLink()) throw new Error("task_artifact_owner_root_invalid");
+	return new ManagedSessionDescendantStore(
+		context.rootAuthority,
+		context.sessionsRoot,
+		undefined,
+		context.securityPolicy,
+		context.profileAgentDir,
+		{
+			canonicalPath: context.sessionsRoot,
+			dev: BigInt.asUintN(64, stat.dev),
+			ino: BigInt.asUintN(64, stat.ino),
+		},
+	);
+}
+
+function parseOwnerManifest(bytes: Uint8Array): OwnerManifest {
+	let parsed: unknown;
+	try {
+		parsed = JSON.parse(Buffer.from(bytes).toString("utf8"));
+	} catch {
+		throw new Error("task_artifact_owner_manifest_invalid");
+	}
+	if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed) || Object.keys(parsed).length !== 5)
+		throw new Error("task_artifact_owner_manifest_invalid");
+	const record = parsed as Record<string, unknown>;
+	if (typeof record.sessionId !== "string" || record.sessionId.length === 0)
+		throw new Error("task_artifact_owner_manifest_invalid");
+	let locator: TaskArtifactOwnerLocator | undefined;
+	try {
+		locator = parseTaskArtifactOwnerLocator({
+			schemaVersion: record.schemaVersion,
+			ownerId: record.ownerId,
+			directoryDev: record.directoryDev,
+			directoryIno: record.directoryIno,
+		});
+	} catch {
+		throw new Error("task_artifact_owner_manifest_invalid");
+	}
+	if (!locator) throw new Error("task_artifact_owner_manifest_invalid");
+	return { ...locator, sessionId: record.sessionId };
+}
+
+export function readOwnerManifest(
+	store: ManagedSessionDescendantStore,
+	locator: TaskArtifactOwnerLocator,
+	relativePath = manifestRelativePath(locator.ownerId),
+): OwnerManifest {
+	const manifest = store.readExpected(relativePath);
+	if (!manifest) throw new Error("task_artifact_owner_manifest_missing");
+	const parsed = parseOwnerManifest(manifest.bytes);
+	if (
+		parsed.ownerId !== locator.ownerId ||
+		parsed.directoryDev !== locator.directoryDev ||
+		parsed.directoryIno !== locator.directoryIno
+	)
+		throw new Error("task_artifact_owner_manifest_mismatch");
+	return parsed;
+}
+
+export function assertOwnerDirectoryExists(context: TaskArtifactOwnerStorageContext, ownerId: string): void {
+	const parent = path.join(context.sessionsRoot, OWNER_DIRECTORY);
+	const owner = path.join(parent, ownerId);
+	for (const candidate of [parent, owner]) {
+		let stat: fs.BigIntStats;
+		try {
+			stat = fs.lstatSync(candidate, { bigint: true });
+		} catch (error) {
+			if ((error as NodeJS.ErrnoException).code === "ENOENT") throw new Error("task_artifact_owner_missing");
+			throw error;
+		}
+		if (!stat.isDirectory() || stat.isSymbolicLink()) throw new Error("task_artifact_owner_replaced");
+	}
+}
+
+export function assertOwnerIdentity(store: ManagedSessionDescendantStore, locator: TaskArtifactOwnerLocator): void {
+	const identity = store.subtreeRootAuthority;
+	if (identity.dev.toString() !== locator.directoryDev || identity.ino.toString() !== locator.directoryIno)
+		throw new Error("task_artifact_owner_identity_mismatch");
+}
+
+export function openOwnerStore(
+	context: TaskArtifactOwnerStorageContext,
+	rootStore: ManagedSessionDescendantStore,
+	locator: TaskArtifactOwnerLocator,
+	sessionId: string,
+): ManagedSessionDescendantStore {
+	if (locator.ownerId !== ownerIdForSession(sessionId)) throw new Error("task_artifact_owner_session_mismatch");
+	assertOwnerDirectoryExists(context, locator.ownerId);
+	const manifest = readOwnerManifest(rootStore, locator);
+	if (manifest.sessionId !== sessionId) throw new Error("task_artifact_owner_session_mismatch");
+	const identity = rootStore.captureDirectoryIdentity(ownerRelativePath(locator.ownerId));
+	if (identity.dev !== locator.directoryDev || identity.ino !== locator.directoryIno)
+		throw new Error("task_artifact_owner_identity_mismatch");
+	const ownerPath = path.join(context.sessionsRoot, ownerRelativePath(locator.ownerId));
+	const ownerStore = new ManagedSessionDescendantStore(
+		context.rootAuthority,
+		ownerPath,
+		undefined,
+		context.securityPolicy,
+		context.profileAgentDir,
+		{
+			canonicalPath: ownerPath,
+			dev: BigInt(locator.directoryDev),
+			ino: BigInt(locator.directoryIno),
+		},
+	);
+	try {
+		assertOwnerIdentity(ownerStore, locator);
+		readOwnerManifest(ownerStore, locator, OWNER_MANIFEST);
+		return ownerStore;
+	} catch (error) {
+		ownerStore.close();
+		throw error;
+	}
+}
+
+export function locatorFromManifest(manifest: OwnerManifest): TaskArtifactOwnerLocator {
+	return {
+		schemaVersion: OWNER_SCHEMA_VERSION,
+		ownerId: manifest.ownerId,
+		directoryDev: manifest.directoryDev,
+		directoryIno: manifest.directoryIno,
+	};
+}
+
+export function captureValidatedOwnerTree(
+	context: TaskArtifactOwnerStorageContext,
+	rootStore: ManagedSessionDescendantStore,
+	sessionId: string,
+	locator: TaskArtifactOwnerLocator,
+): NativeDirectoryTreeSnapshot {
+	if (locator.ownerId !== ownerIdForSession(sessionId)) throw new Error("task_artifact_owner_session_mismatch");
+	assertOwnerDirectoryExists(context, locator.ownerId);
+	const manifest = readOwnerManifest(rootStore, locator);
+	if (manifest.sessionId !== sessionId) throw new Error("task_artifact_owner_session_mismatch");
+	const tree = rootStore.captureTree(ownerRelativePath(locator.ownerId));
+	if (tree.rootDev !== locator.directoryDev || tree.rootIno !== locator.directoryIno)
+		throw new Error("task_artifact_owner_identity_mismatch");
+	return tree;
+}
+
+export function captureOwnerTreeIfPresent(
+	context: TaskArtifactOwnerStorageContext,
+	rootStore: ManagedSessionDescendantStore,
+	ownerId: string,
+	pathname: string,
+): NativeDirectoryTreeSnapshot | undefined {
+	if (!isOwnerRetainedRoot(context, ownerId, pathname))
+		throw new Error("task_artifact_owner_retained_root_unrecognized");
+	let named: fs.BigIntStats;
+	try {
+		named = fs.lstatSync(pathname, { bigint: true });
+	} catch (error) {
+		if ((error as NodeJS.ErrnoException).code === "ENOENT") return undefined;
+		throw error;
+	}
+	if (!named.isDirectory() || named.isSymbolicLink()) throw new Error("task_artifact_owner_retained_root_replaced");
+	const relative = path.relative(context.sessionsRoot, pathname).split(path.sep).join("/");
+	assertSafeRelativePath(relative);
+	return freezeTreeSnapshot(rootStore.captureTree(relative));
+}
+
+export function ownerTreeHasPendingManagedPublication(snapshot: NativeDirectoryTreeSnapshot): boolean {
+	return snapshot.entries.some(entry =>
+		/^\..+\.[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.(?:staging|replacement)$/u.test(
+			path.posix.basename(entry.relativePath),
+		),
+	);
+}
+
+/** Capture exact owner evidence without repairing its security, timestamps, or namespace. */
+export function captureTaskArtifactOwnerDeletionEvidence(
+	context: TaskArtifactOwnerStorageContext,
+	sessionId: string,
+	locatorValue: unknown,
+): TaskArtifactOwnerDeletionEvidence | undefined {
+	const locator = parseTaskArtifactOwnerLocator(locatorValue);
+	if (!locator) return undefined;
+	const rootStore = newSessionRootStore(context);
+	try {
+		rootStore.verifyRootSecurity();
+		const parentIdentity: TaskArtifactOwnerParentIdentity = rootStore.captureDirectoryIdentity(OWNER_DIRECTORY);
+		const treeSnapshot = captureValidatedOwnerTree(context, rootStore, sessionId, locator);
+		// This refuses to capture during publication; it does not revoke independent open descriptors.
+		if (ownerTreeHasPendingManagedPublication(treeSnapshot))
+			throw new Error("task_artifact_owner_writer_not_quiescent");
+		const parentAfter = rootStore.captureDirectoryIdentity(OWNER_DIRECTORY);
+		if (!sameOwnerParentIdentity(parentIdentity, parentAfter))
+			throw new Error("task_artifact_owner_parent_changed_during_capture");
+		return immutableDeletionEvidence(sessionId, locator, parentIdentity, treeSnapshot);
+	} finally {
+		rootStore.close();
+	}
+}