tech-log-frontend/scripts/run-and-validate-provider.ts

import { spawn } from "node:child_process";
import { randomBytes } from "node:crypto";
import { constants } from "node:fs";
import { access, appendFile, lstat } from "node:fs/promises";
import path from "node:path";

import {
  provenanceProviderAttestationSchema,
  vulnerabilityProviderReportSchema,
} from "./lib/provider-evidence.ts";
import { readBoundedRegularFile } from "./lib/ci-artifact-validator.ts";
import { readProviderTrust } from "./lib/provider-trust.ts";
import { superviseProviderEvidence } from "./lib/provider-supervisor.ts";
import { serializeValidatedJsonArtifact } from "./lib/validated-json-artifact.ts";
import {
  assertSafePublishLeaf,
  ensureSafePublishDirectory,
} from "./lib/ci-gate-log.ts";
import {
  encodeProviderBwrapInput,
  encodeProviderScopeFrame,
  formatProviderCgroupUnitName,
  systemctlKillProviderArguments,
  systemdRunProviderArguments,
} from "./lib/provider-cgroup.ts";
import {
  assertProviderGuardianLeasePaths,
  createProviderScopeGuardianLatch,
  startProviderGuardian,
  type ProviderGuardianLease,
} from "./lib/provider-guardian-client.ts";
import { createProviderOutputLimiter } from "./lib/provider-output-limiter.ts";

const kind = process.argv[process.argv.indexOf("--kind") + 1];
const PROVIDER_TMP_BYTES = 16_777_216;
const PROVIDER_MASK_BYTES = 1_048_576;
const PROVIDER_MAX_OUTPUT_BYTES = 1_048_576;
const DEFAULT_PROVIDER_CPU_SECONDS = 1_200;
const DEFAULT_PROVIDER_TIMEOUT_MS = 30 * 60 * 1_000;
const PROVIDER_POSTPROCESS_TIMEOUT_MS = 10 * 60 * 1_000;
const PROVIDER_REAP_TIMEOUT_MS = 5_000;
const PROVIDER_CONTROL_TIMEOUT_MS = 5_000;
const PROVIDER_CONTROL_MAX_OUTPUT_BYTES = 65_536;
const PROVIDER_CONTROL_POLL_MS = 25;
const MINIMUM_PROVIDER_SYSTEMD_VERSION = 254;
if (kind !== "vulnerability" && kind !== "provenance") {
  process.stderr.write("Usage: run-and-validate-provider --kind vulnerability|provenance\n");
  process.exit(2);
}
const command =
  kind === "vulnerability"
    ? process.env.VULNERABILITY_PROVIDER_COMMAND
    : process.env.PROVENANCE_PROVIDER_COMMAND;
const reportPath =
  kind === "vulnerability"
    ? process.env.VULNERABILITY_REPORT_PATH
    : process.env.PROVENANCE_ATTESTATION_PATH;
const sealedPath = process.env.VALIDATED_PROVIDER_REPORT_PATH;
const archivePath = process.env.CANDIDATE_ARCHIVE_PATH;
const archiveSha256 = process.env.CANDIDATE_ARCHIVE_SHA256;
const publicKeyPath = kind === "vulnerability"
  ? process.env.VULNERABILITY_PUBLIC_KEY_PATH
  : process.env.PROVENANCE_PUBLIC_KEY_PATH;
const keyId = kind === "vulnerability"
  ? process.env.VULNERABILITY_KEY_ID
  : process.env.PROVENANCE_KEY_ID;
const runId = process.env.GITEA_RUN_ID ?? process.env.GITHUB_RUN_ID ?? process.env.CI_RUN_ID;
const runAttemptSource = process.env.GITEA_RUN_ATTEMPT ??
  process.env.GITHUB_RUN_ATTEMPT ?? process.env.CI_RUN_ATTEMPT;
const sourceRevision = process.env.EXPECTED_SOURCE_REVISION ?? process.env.VITE_COMMIT_SHA;
if (
  !command ||
  !reportPath ||
  !sealedPath ||
  !archivePath ||
  !archiveSha256 ||
  !publicKeyPath ||
  !keyId ||
  !runId ||
  !runAttemptSource ||
  !sourceRevision
) {
  process.stderr.write("Provider supervisor environment is incomplete\n");
  process.exit(2);
}
const runAttempt = Number(runAttemptSource);
if (!Number.isInteger(runAttempt) || runAttempt < 1 || runAttempt > 1_000) {
  throw new TypeError("provider supervisor run attempt is invalid");
}

const workspaceRoot = process.cwd();
const reportAbsolute = path.resolve(reportPath);
const rawDirectory = path.dirname(reportAbsolute);
const sealedAbsolute = path.resolve(sealedPath);
const expectedRawLeaf = kind === "vulnerability"
  ? "vulnerability-report.json"
  : "provenance-attestation.json";
const expectedRawDirectory = path.resolve(workspaceRoot, "provider-evidence/untrusted");
if (
  reportAbsolute !== path.join(expectedRawDirectory, expectedRawLeaf) ||
  path.basename(rawDirectory) !== "untrusted" ||
  path.dirname(rawDirectory) !== path.dirname(sealedAbsolute) ||
  reportAbsolute === sealedAbsolute
) {
  throw new TypeError("provider raw and sealed evidence paths are not isolated");
}
await prepareMissingProviderOutput(workspaceRoot, reportAbsolute, reportPath, "raw provider report");
await prepareMissingProviderOutput(workspaceRoot, sealedAbsolute, sealedPath, "sealed provider report");
await access("/usr/bin/bwrap", constants.X_OK).catch(() => {
  throw new Error("provider sandbox unavailable: /usr/bin/bwrap is required");
});
await access("/usr/bin/prlimit", constants.X_OK).catch(() => {
  throw new Error("provider sandbox unavailable: /usr/bin/prlimit is required");
});
await access("/usr/bin/systemd-run", constants.X_OK).catch(() => {
  throw new Error("provider cgroup unavailable: /usr/bin/systemd-run is required");
});
await access("/usr/bin/systemctl", constants.X_OK).catch(() => {
  throw new Error("provider cgroup unavailable: /usr/bin/systemctl is required");
});
await assertProviderCgroupManagerAvailable();
const trust = await readProviderTrust(workspaceRoot, publicKeyPath, keyId);
if (!trust) throw new TypeError("provider supervisor trust key is invalid");
let guardianLease: ProviderGuardianLease | undefined;
let guardianTerminalStarted = false;
try {
  const providerWallTimeoutMs = providerTimeoutMs();
  const supervised = await superviseProviderEvidence({
    kind,
    archivePath,
    expectedArchiveSha256: archiveSha256,
    expectedRun: { id: runId, attempt: runAttempt, sourceRevision },
    trust,
    executeProvider: async ({ candidateRoot, environment }) => {
      guardianLease = await startProviderGuardian({
        kind,
        workspaceRoot,
        leaseMs: providerWallTimeoutMs + PROVIDER_POSTPROCESS_TIMEOUT_MS,
        guardianScript: path.join(workspaceRoot, "scripts/lib/provider-raw-guardian.ts"),
      });
      const activeGuardian = guardianLease;
      assertProviderGuardianLeasePaths(activeGuardian, {
        rawPath: reportAbsolute,
        sealedPath: sealedAbsolute,
      });
      const childEnvironment = createProviderEnvironment(kind, reportPath, environment);
      await runProviderInSandbox(
        kind,
        command,
        childEnvironment,
        activeGuardian.rawPath,
        activeGuardian.rawIdentity,
        workspaceRoot,
        candidateRoot,
        providerWallTimeoutMs,
        activeGuardian.prematureExit,
      );
      await assertOwnedProviderOutput(activeGuardian.rawPath, activeGuardian.rawIdentity);
    },
    captureReport: async () => {
      if (!guardianLease) throw new Error("provider raw guardian lease was not established");
      await assertOwnedProviderOutput(guardianLease.rawPath, guardianLease.rawIdentity);
      return readBoundedRegularFile({
        root: workspaceRoot,
        relativePath: path.relative(workspaceRoot, guardianLease.rawPath).replaceAll(path.sep, "/"),
        maxBytes: 8_388_608,
      });
    },
  });
  if (!guardianLease) throw new Error("provider raw guardian lease was not established");
  await assertSafePublishLeaf(sealedAbsolute, sealedPath);
  await guardianLease.publish(serializeValidatedJsonArtifact({
    path: sealedPath,
    schema:
      kind === "vulnerability"
        ? vulnerabilityProviderReportSchema
        : provenanceProviderAttestationSchema,
    value: supervised.evidence,
  }));
  if (process.env.GITHUB_OUTPUT) {
    await appendFile(
      process.env.GITHUB_OUTPUT,
      `invocation_nonce=${supervised.invocationNonce}\n`,
      "utf8",
    );
  }
  guardianTerminalStarted = true;
  await guardianLease.commit();
} catch (providerError) {
  const failures = [toError(providerError)];
  if (guardianLease && !guardianTerminalStarted) {
    try {
      await guardianLease.abort();
    } catch (guardianError) {
      failures.push(toError(guardianError));
    }
  }
  if (failures.length > 1) {
    throw new AggregateError(failures, "provider lifecycle and owned output cleanup failed", {
      cause: providerError,
    });
  }
  throw providerError;
}
process.stdout.write(`${kind} provider supervised validation: PASS\n`);

function createProviderEnvironment(
  providerKind: "vulnerability" | "provenance",
  rawReportPath: string,
  bindings: Readonly<Record<string, string>>,
): NodeJS.ProcessEnv {
  const environment: NodeJS.ProcessEnv = {
    PATH: process.env.PATH ?? "/usr/local/bin:/usr/bin:/bin",
    HOME: "/tmp/provider-home",
    TMPDIR: "/tmp",
    CI: "true",
    GITHUB_ENV: "/tmp/github-env",
    GITHUB_PATH: "/tmp/github-path",
    ...bindings,
    ...(providerKind === "vulnerability"
      ? { VULNERABILITY_REPORT_PATH: rawReportPath }
      : { PROVENANCE_ATTESTATION_PATH: rawReportPath }),
  };
  for (const name of ["LANG", "LC_ALL"] as const) {
    if (process.env[name]) environment[name] = process.env[name];
  }
  const credentialPrefix = `${providerKind.toUpperCase()}_PROVIDER_`;
  for (const [name, value] of Object.entries(process.env)) {
    if (name.startsWith(credentialPrefix) && !name.endsWith("_COMMAND") && value) {
      environment[name] = value;
    }
  }
  return environment;
}

async function runProviderInSandbox(
  providerKind: "vulnerability" | "provenance",
  command: string,
  environment: NodeJS.ProcessEnv,
  reportAbsolute: string,
  reportIdentity: Readonly<{ dev: number; ino: number }>,
  workspaceRoot: string,
  candidateRoot: string,
  timeoutMs: number,
  guardianExit: Promise<Error>,
): Promise<void> {
  const cpuSeconds = providerCpuSeconds();
  const bwrapArguments = [
    "--die-with-parent", "--new-session", "--as-pid-1",
    "--unshare-pid", "--unshare-ipc", "--unshare-uts", "--unshare-net",
    "--dev", "/dev", "--remount-ro", "/dev",
    "--proc", "/proc", "--remount-ro", "/proc",
    "--size", String(PROVIDER_TMP_BYTES), "--tmpfs", "/tmp",
    "--dir", "/tmp/provider-home",
    "--size", String(PROVIDER_MASK_BYTES), "--tmpfs", "/etc",
  ];
  for (const source of ["/usr", "/bin", "/lib", "/lib64"]) {
    if (await exists(source)) bwrapArguments.push("--ro-bind", source, source);
  }
  bwrapArguments.push("--ro-bind", process.execPath, "/tmp/node");
  for (const source of [
    "/etc/ca-certificates", "/etc/ssl", "/etc/nsswitch.conf", "/etc/passwd", "/etc/group",
  ]) {
    if (await exists(source)) bwrapArguments.push("--ro-bind", source, source);
  }
  bwrapArguments.push("--remount-ro", "/etc");
  for (const directory of missingDestinationAncestors(workspaceRoot)) {
    bwrapArguments.push("--dir", directory);
  }
  bwrapArguments.push("--ro-bind", workspaceRoot, workspaceRoot);
  if (await exists(path.join(workspaceRoot, ".git"))) {
    bwrapArguments.push(
      "--size", String(PROVIDER_MASK_BYTES),
      "--tmpfs", path.join(workspaceRoot, ".git"),
      "--remount-ro", path.join(workspaceRoot, ".git"),
    );
  }
  bwrapArguments.push(
    "--ro-bind", candidateRoot, "/candidate",
    "--remount-ro", "/tmp",
    "--remount-ro", "/",
    "--bind", reportAbsolute, reportAbsolute,
    "--chdir", workspaceRoot,
  );
  /**
   * Everything above is a bubblewrap *option* and travels in the args file, so
   * host paths never reach `/proc/<pid>/cmdline`. The command below cannot: an
   * args file's option stream ends at the first non-option and bubblewrap drops
   * the remainder, so a command written there is never executed. It stays on
   * real argv, and it is safe there because the provider command and its
   * credentials are passed as `--setenv PROVIDER_COMMAND` inside the args file
   * and only expanded by the innermost shell.
   */
  const bwrapCommand = [
    "/usr/bin/prlimit",
    "--core=0:0",
    "--fsize=8388607:8388607",
    "--nofile=64:64",
    `--cpu=${cpuSeconds}:${cpuSeconds}`,
    "--", "/bin/sh", "-eu", "-c",
    'exec /bin/sh -eu -c "$PROVIDER_COMMAND"',
  ];
  const unitName = formatProviderCgroupUnitName(
    providerKind,
    process.pid,
    randomBytes(12).toString("hex"),
  );
  const bwrapInput = encodeProviderBwrapInput(bwrapArguments, {
    ...environment,
    PATH: `/tmp:${environment.PATH ?? ""}`,
    PROVIDER_COMMAND: command,
  });
  const scopeFrame = encodeProviderScopeFrame({
    bwrapInput,
    bwrapCommand,
    reportPath: reportAbsolute,
    reportDev: reportIdentity.dev,
    reportIno: reportIdentity.ino,
  });
  await waitForProvider(
    spawn("/usr/bin/systemd-run", systemdRunProviderArguments(
      unitName,
      timeoutMs,
      cpuSeconds,
      process.execPath,
      path.join(workspaceRoot, "scripts/lib/provider-scope-wrapper.ts"),
      reportAbsolute,
      reportIdentity.dev,
      reportIdentity.ino,
    ), {
      env: providerCgroupClientEnvironment(),
      stdio: ["pipe", "pipe", "pipe"],
    }),
    timeoutMs,
    unitName,
    scopeFrame,
    guardianExit,
  );
}

async function waitForProvider(
  child: ReturnType<typeof spawn>,
  timeoutMs: number,
  unitName: string,
  scopeFrame: Buffer,
  guardianExit: Promise<Error>,
): Promise<void> {
  let termination: "guardian" | "timeout" | "output" | undefined;
  let guardianError: Error | undefined;
  let signalTermination!: () => void;
  let kill: Promise<void> | undefined;
  const terminationStarted = new Promise<void>((resolve) => { signalTermination = resolve; });
  const close = new Promise<Readonly<{ code: number | null; error?: Error; signal: NodeJS.Signals | null }>>((resolve) => {
    child.once("error", (error) => resolve({ code: null, error, signal: null }));
    child.once("close", (code, signal) => resolve({ code, signal }));
  });
  let inputError: Error | undefined;
  child.stdin?.once("error", (error) => { inputError = error; });
  if (child.stdin) child.stdin.write(scopeFrame);
  else inputError = new Error("systemd-run provider argument pipe is unavailable");
  const terminate = (reason: "guardian" | "timeout" | "output"): void => {
    if (termination) return;
    termination = reason;
    kill = killProviderUnit(unitName);
    signalTermination();
  };
  const guardianLatch = createProviderScopeGuardianLatch(guardianExit);
  void guardianLatch.activeFailure.then((error) => {
    guardianError = error;
    terminate("guardian");
  });
  const outputLimiter = createProviderOutputLimiter(
    PROVIDER_MAX_OUTPUT_BYTES,
    () => terminate("output"),
  );
  /**
   * Lines the sandbox tooling itself emits, kept so a launch failure can say
   * why. Everything else the child writes is provider output and may carry
   * credentials, so it is counted and discarded as before.
   *
   * Without this a sandbox that never started reported only `exit=1`, and the
   * actual cause — `bwrap: loopback: Failed RTM_NEWADDR: Operation not
   * permitted` on a host with `kernel.apparmor_restrict_unprivileged_userns=1`
   * — was invisible. That turned a host restriction into an unexplained
   * product failure.
   */
  const SANDBOX_DIAGNOSTIC = /^(?:bwrap|prlimit|systemd-run|systemctl):\s.*$/gmu;
  const sandboxDiagnostics: string[] = [];
  const capture = (chunk: Buffer | string): void => {
    for (const line of String(chunk).matchAll(SANDBOX_DIAGNOSTIC)) {
      if (sandboxDiagnostics.length < 8 && !sandboxDiagnostics.includes(line[0])) {
        sandboxDiagnostics.push(line[0]);
      }
    }
    if (termination) return;
    outputLimiter.consume(chunk);
  };
  child.stdout?.on("data", capture);
  child.stderr?.on("data", capture);
  const timeout = setTimeout(() => terminate("timeout"), timeoutMs);
  try {
    const first = await Promise.race([
      close.then((result) => ({ type: "close" as const, result })),
      terminationStarted.then(() => ({ type: "termination" as const })),
    ]);
    let collection: Promise<void> | undefined;
    if (first.type === "close" && !termination) {
      collection = waitForProviderUnitCollected(unitName);
      const scopeOutcome = await Promise.race([
        collection.then(() => "collected" as const),
        terminationStarted.then(() => "termination" as const),
      ]);
      if (scopeOutcome === "collected") {
        await guardianLatch.close();
        const boundaryFailure = guardianLatch.failure();
        if (boundaryFailure && !termination) {
          guardianError = boundaryFailure;
          terminate("guardian");
        }
      }
    }
    if (termination) {
      let killError: Error | undefined;
      try { await kill; } catch (error) { killError = toError(error); child.kill("SIGKILL"); }
      const closed = await waitForProviderClose(close);
      if (!closed) child.kill("SIGKILL");
      let collectionError: Error | undefined;
      try {
        await (collection ?? waitForProviderUnitCollected(unitName));
      } catch (error) {
        collectionError = toError(error);
      }
      await guardianLatch.close();
      const reason = termination === "timeout"
        ? "sandboxed external provider command timed out"
        : termination === "output"
          ? `sandboxed external provider output exceeded the ${PROVIDER_MAX_OUTPUT_BYTES}-byte aggregate limit`
          : `provider raw guardian failed${guardianError ? `: ${guardianError.message}` : ""}`;
      if (!closed) throw new Error(`${reason} and systemd-run did not close within the reap bound`);
      if (collectionError) throw new Error(`${reason}; provider cgroup collection failed: ${collectionError.message}`);
      if (killError) throw new Error(`${reason}; provider cgroup kill failed: ${killError.message}`);
      throw new Error(reason);
    }
    const result = first.type === "close" ? first.result : await close;
    await collection;
    if (result.error) throw result.error;
    if (result.code !== 0 || result.signal !== null) {
      throw new Error(
        `sandboxed external provider failed: exit=${result.code ?? "none"}, ` +
          `signal=${result.signal ?? "none"}` +
          (sandboxDiagnostics.length > 0
            ? `; sandbox reported: ${sandboxDiagnostics.join("; ")}`
            : ""),
      );
    }
    if (inputError) throw inputError;
  } finally {
    clearTimeout(timeout);
    await guardianLatch.close();
  }
}

async function waitForProviderClose(
  close: Promise<Readonly<{ code: number | null; error?: Error; signal: NodeJS.Signals | null }>>,
): Promise<boolean> {
  let timer: NodeJS.Timeout | undefined;
  const closed = await Promise.race([
    close.then(() => true),
    new Promise<false>((resolve) => { timer = setTimeout(() => resolve(false), PROVIDER_REAP_TIMEOUT_MS); }),
  ]);
  if (timer) clearTimeout(timer);
  return closed;
}

async function assertProviderCgroupManagerAvailable(): Promise<void> {
  const output = await runBoundedSystemctl(
    ["--user", "show", "--property=Version", "--value"],
    "provider cgroup user manager probe",
  );
  const match = /^([0-9]+)/u.exec(output.trim());
  const version = match ? Number(match[1]) : Number.NaN;
  if (!Number.isSafeInteger(version) || version < MINIMUM_PROVIDER_SYSTEMD_VERSION) {
    throw new Error(`provider cgroup unavailable: systemd ${MINIMUM_PROVIDER_SYSTEMD_VERSION} or newer is required`);
  }
}

async function killProviderUnit(unitName: string): Promise<void> {
  await runBoundedSystemctl(systemctlKillProviderArguments(unitName), "provider cgroup unit kill");
}

async function waitForProviderUnitCollected(unitName: string): Promise<void> {
  const deadline = Date.now() + PROVIDER_CONTROL_TIMEOUT_MS;
  let loadState = "unknown";
  while (Date.now() <= deadline) {
    loadState = (await runBoundedSystemctl(
      ["--user", "show", unitName, "--property=LoadState", "--value"],
      "provider cgroup collection probe",
    )).trim();
    if (loadState === "not-found") return;
    await new Promise<void>((resolve) => setTimeout(resolve, PROVIDER_CONTROL_POLL_MS));
  }
  throw new Error(`provider unit remained loaded with state ${loadState || "unknown"}`);
}

async function runBoundedSystemctl(arguments_: readonly string[], label: string): Promise<string> {
  return await new Promise<string>((resolve, reject) => {
    const child = spawn("/usr/bin/systemctl", arguments_, {
      env: providerCgroupClientEnvironment(),
      stdio: ["ignore", "pipe", "pipe"],
    });
    let bytes = 0;
    const chunks: Buffer[] = [];
    let settled = false;
    let termination: "output" | "timeout" | undefined;
    let reap: NodeJS.Timeout | undefined;
    const finish = (error?: Error): void => {
      if (settled) return;
      settled = true;
      clearTimeout(timeout);
      if (reap) clearTimeout(reap);
      error ? reject(error) : resolve(Buffer.concat(chunks).toString("utf8"));
    };
    const terminate = (reason: "output" | "timeout"): void => {
      if (termination) return;
      termination = reason;
      child.kill("SIGKILL");
      reap = setTimeout(() => finish(new Error(`${label} ${reason} bound was exceeded and systemctl did not close`)), PROVIDER_REAP_TIMEOUT_MS);
    };
    const capture = (chunk: Buffer | string): void => {
      if (termination) return;
      const value = Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk);
      const remaining = PROVIDER_CONTROL_MAX_OUTPUT_BYTES - bytes;
      if (remaining > 0) { chunks.push(value.subarray(0, remaining)); bytes += Math.min(value.length, remaining); }
      if (value.length > remaining) terminate("output");
    };
    child.stdout?.on("data", capture);
    child.stderr?.on("data", capture);
    const timeout = setTimeout(() => terminate("timeout"), PROVIDER_CONTROL_TIMEOUT_MS);
    child.once("error", (error) => finish(error));
    child.once("close", (code, signal) => {
      if (termination) return finish(new Error(`${label} ${termination} bound was exceeded`));
      if (code === 0 && signal === null) return finish();
      const detail = Buffer.concat(chunks).toString("utf8").trim();
      finish(new Error(`${label} failed: exit=${code ?? "none"}, signal=${signal ?? "none"}${detail ? `, output=${detail}` : ""}`));
    });
  });
}

function providerCgroupClientEnvironment(): NodeJS.ProcessEnv {
  const environment: NodeJS.ProcessEnv = { PATH: "/usr/bin:/bin" };
  for (const name of ["DBUS_SESSION_BUS_ADDRESS", "HOME", "LANG", "LC_ALL", "LOGNAME", "USER", "XDG_RUNTIME_DIR"] as const) {
    if (process.env[name]) environment[name] = process.env[name];
  }
  return environment;
}

function providerCpuSeconds(): number {
  const value = process.env.PROVIDER_SUPERVISOR_CPU_SECONDS;
  if (!value) return DEFAULT_PROVIDER_CPU_SECONDS;
  const parsed = Number(value);
  if (!Number.isSafeInteger(parsed) || parsed <= 0 || parsed > DEFAULT_PROVIDER_CPU_SECONDS) {
    throw new TypeError("PROVIDER_SUPERVISOR_CPU_SECONDS must be a positive integer no greater than 1200");
  }
  return parsed;
}

function providerTimeoutMs(): number {
  const value = process.env.PROVIDER_SUPERVISOR_TIMEOUT_MS;
  if (!value) return DEFAULT_PROVIDER_TIMEOUT_MS;
  const parsed = Number(value);
  if (!Number.isSafeInteger(parsed) || parsed <= 0 || parsed > DEFAULT_PROVIDER_TIMEOUT_MS) {
    throw new TypeError("PROVIDER_SUPERVISOR_TIMEOUT_MS must be a positive integer no greater than 1800000");
  }
  return parsed;
}

function toError(error: unknown): Error {
  return error instanceof Error ? error : new Error(String(error));
}

function missingDestinationAncestors(target: string): string[] {
  const ancestors: string[] = [];
  let current = path.dirname(path.resolve(target));
  while (current !== path.parse(current).root && !["/usr", "/bin", "/lib", "/lib64", "/tmp"].includes(current)) {
    ancestors.push(current);
    current = path.dirname(current);
  }
  return ancestors.reverse();
}

async function exists(target: string): Promise<boolean> {
  try {
    await lstat(target);
    return true;
  } catch (error) {
    if (hasErrorCode(error, "ENOENT")) return false;
    throw error;
  }
}

async function prepareMissingProviderOutput(
  root: string,
  absolutePath: string,
  configuredPath: string,
  label: string,
): Promise<void> {
  await ensureSafePublishDirectory(root, path.dirname(absolutePath));
  await assertSafePublishLeaf(absolutePath, configuredPath);
  try {
    await lstat(absolutePath);
    throw new Error(`${label} already exists: ${configuredPath}`);
  } catch (error) {
    if (!hasErrorCode(error, "ENOENT")) throw error;
  }
}

async function assertOwnedProviderOutput(
  absolutePath: string,
  identity: Readonly<{ dev: number; ino: number }>,
): Promise<void> {
  const metadata = await lstat(absolutePath);
  if (
    metadata.isSymbolicLink() ||
    !metadata.isFile() ||
    metadata.dev !== identity.dev ||
    metadata.ino !== identity.ino
  ) {
    throw new Error("provider raw output identity changed");
  }
}

function hasErrorCode(error: unknown, code: string): boolean {
  return Boolean(error && typeof error === "object" && "code" in error && error.code === code);
}