gstack/browse/test/path-validation.test.ts

import { beforeAll, describe, it, expect } from 'bun:test';
import { chromium } from 'playwright';
import { validateOutputPath } from '../src/path-security';
import { validateReadPath, SENSITIVE_COOKIE_NAME, SENSITIVE_COOKIE_VALUE } from '../src/read-commands';
import { BLOCKED_METADATA_HOSTS } from '../src/url-validation';
import { mkdirSync, mkdtempSync, rmSync, symlinkSync, unlinkSync, writeFileSync, realpathSync } from 'fs';
import { tmpdir, userInfo } from 'os';
import { join } from 'path';

describe('validateOutputPath', () => {
  it('allows paths within /tmp', () => {
    expect(() => validateOutputPath('/tmp/screenshot.png')).not.toThrow();
  });

  it('allows paths in subdirectories of /tmp', () => {
    expect(() => validateOutputPath('/tmp/browse/output.png')).not.toThrow();
  });

  it('allows paths within cwd', () => {
    expect(() => validateOutputPath(`${process.cwd()}/output.png`)).not.toThrow();
  });

  it('blocks paths outside safe directories', () => {
    expect(() => validateOutputPath('/etc/cron.d/backdoor.png')).toThrow(/Path must be within/);
  });

  it('blocks /tmpevil prefix collision', () => {
    expect(() => validateOutputPath('/tmpevil/file.png')).toThrow(/Path must be within/);
  });

  it('blocks home directory paths', () => {
    expect(() => validateOutputPath('/Users/someone/file.png')).toThrow(/Path must be within/);
  });

  it('blocks path traversal via ..', () => {
    expect(() => validateOutputPath('/tmp/../etc/passwd')).toThrow(/Path must be within/);
  });
});

describe('upload command path validation', () => {
  let observations: Record<string, {
    error: string | null;
    result: string | null;
    files: { name: string; text: string }[];
    inputEvents: number;
  }>;

  beforeAll(() => {
    const root = mkdtempSync(join(userInfo().homedir, 'gstack-upload-paths-'));
    try {
      for (const dir of ['home', 'state', 'project', 'private', 'tmp']) {
        mkdirSync(join(root, dir), { mode: 0o700 });
      }
      const probe = Bun.spawnSync([
        process.execPath, join(import.meta.dir, 'fixtures', 'upload-path-validation.ts'), chromium.executablePath(),
      ], {
        cwd: join(root, 'project'),
        env: {
          ...process.env,
          HOME: join(root, 'home'),
          USERPROFILE: join(root, 'home'),
          GSTACK_HOME: join(root, 'state'),
          CLAUDE_PLUGIN_DATA: '',
          XDG_CONFIG_HOME: join(root, 'home', '.config'),
          XDG_CACHE_HOME: join(root, 'home', '.cache'),
          CHROMIUM_PROFILE: join(root, 'profile'),
          TMPDIR: join(root, 'tmp'),
          TMP: join(root, 'tmp'),
          TEMP: join(root, 'tmp'),
        },
        timeout: 60_000,
      });
      expect(probe.exitCode, probe.stderr.toString()).toBe(0);
      observations = JSON.parse(probe.stdout.toString());
    } finally {
      rmSync(root, { recursive: true, force: true });
    }
  }, 70_000);

  for (const selector of ['css', 'ref']) {
    for (const scenario of [
      'relative-file-link', 'absolute-file-link', 'absolute-outside', 'relative-traversal',
      'relative-directory-link', 'absolute-directory-link', 'outside-directory-upload',
      'mixed-valid-first', 'mixed-invalid-first', 'mixed-outside-absolute',
    ]) {
      it(`${selector}: rejects ${scenario} before delivering any file`, () => {
        const actual = observations[`${selector}:${scenario}`];
        expect(actual, JSON.stringify(actual)).toEqual({
          error: expect.stringMatching(/Path must be within|Path traversal/),
          result: null,
          files: [],
          inputEvents: 0,
        });
      });
    }

    for (const scenario of ['broken-link', 'missing-file', 'mixed-missing-file']) {
      it(`${selector}: rejects ${scenario} before delivering any file`, () => {
        expect(observations[`${selector}:${scenario}`]).toEqual({
          error: expect.stringContaining('File not found'),
          result: null,
          files: [],
          inputEvents: 0,
        });
      });
    }

    for (const scenario of ['relative-allowed', 'absolute-allowed', 'safe-file-link', 'safe-directory-link', 'safe-directory-upload']) {
      it(`${selector}: uploads checked target bytes for ${scenario}`, () => {
        expect(observations[`${selector}:${scenario}`]).toEqual({
          error: null,
          result: expect.stringContaining('Uploaded:'),
          files: [{ name: 'allowed.txt', text: 'synthetic allowed bytes' }],
          inputEvents: 1,
        });
      });
    }

    it(`${selector}: preserves allowed temp and multi-file uploads`, () => {
      expect(observations[`${selector}:multiple-allowed`]).toEqual({
        error: null,
        result: expect.stringContaining('Uploaded:'),
        files: [
          { name: 'allowed.txt', text: 'synthetic allowed bytes' },
          { name: 'temp.txt', text: 'synthetic temp bytes' },
        ],
        inputEvents: 1,
      });
    });
  }
});

describe('validateReadPath', () => {
  it('allows absolute paths within /tmp', () => {
    expect(() => validateReadPath('/tmp/script.js')).not.toThrow();
  });

  it('allows absolute paths within cwd', () => {
    expect(() => validateReadPath(`${process.cwd()}/test.js`)).not.toThrow();
  });

  it('allows relative paths without traversal', () => {
    expect(() => validateReadPath('src/index.js')).not.toThrow();
  });

  it('blocks absolute paths outside safe directories', () => {
    expect(() => validateReadPath('/etc/passwd')).toThrow(/Path must be within/);
  });

  it('blocks /tmpevil prefix collision', () => {
    expect(() => validateReadPath('/tmpevil/file.js')).toThrow(/Path must be within/);
  });

  it('blocks path traversal sequences', () => {
    expect(() => validateReadPath('../../../etc/passwd')).toThrow(/Path must be within/);
  });

  it('blocks nested path traversal', () => {
    expect(() => validateReadPath('src/../../etc/passwd')).toThrow(/Path must be within/);
  });

  it('blocks symlink inside safe dir pointing outside', () => {
    const linkPath = join(tmpdir(), 'test-symlink-bypass-' + Date.now());
    try {
      symlinkSync('/etc/passwd', linkPath);
      expect(() => validateReadPath(linkPath)).toThrow(/Path must be within/);
    } finally {
      try { unlinkSync(linkPath); } catch {}
    }
  });

  it('throws clear error on non-ENOENT realpathSync failure', () => {
    // Attempting to resolve a path through a non-directory should throw
    // a descriptive error (ENOTDIR), not silently pass through.
    // Create a regular file, then try to resolve a path through it as if it were a directory.
    const filePath = join(tmpdir(), 'test-notdir-' + Date.now());
    try {
      writeFileSync(filePath, 'not a directory');
      // filePath is a file, so filePath + '/subpath' triggers ENOTDIR
      const invalidPath = join(filePath, 'subpath');
      expect(() => validateReadPath(invalidPath)).toThrow(/Cannot resolve real path|Path must be within/);
    } finally {
      try { unlinkSync(filePath); } catch {}
    }
  });
});

describe('validateOutputPath — symlink resolution', () => {
  it('blocks symlink inside /tmp pointing outside safe dirs', () => {
    const linkPath = join(tmpdir(), 'test-output-symlink-' + Date.now() + '.png');
    try {
      symlinkSync('/etc/passwd', linkPath); // /etc/passwd exists on every Unix — /etc/crontab is absent on Amazon Linux/Fedora minimal;
      expect(() => validateOutputPath(linkPath)).toThrow(/Path must be within/);
    } finally {
      try { unlinkSync(linkPath); } catch {}
    }
  });

  it('allows symlink inside /tmp pointing to another /tmp path', () => {
    // Use /tmp (TEMP_DIR on macOS/Linux), not os.tmpdir() which may be a different path
    const realTmp = realpathSync('/tmp');
    const targetPath = join(realTmp, 'test-output-real-' + Date.now() + '.png');
    const linkPath = join(realTmp, 'test-output-link-' + Date.now() + '.png');
    try {
      writeFileSync(targetPath, '');
      symlinkSync(targetPath, linkPath);
      expect(() => validateOutputPath(linkPath)).not.toThrow();
    } finally {
      try { unlinkSync(linkPath); } catch {}
      try { unlinkSync(targetPath); } catch {}
    }
  });

  it('blocks new file in symlinked directory pointing outside', () => {
    const linkDir = join(tmpdir(), 'test-dirlink-' + Date.now());
    try {
      symlinkSync('/etc', linkDir);
      expect(() => validateOutputPath(join(linkDir, 'evil.png'))).toThrow(/Path must be within/);
    } finally {
      try { unlinkSync(linkDir); } catch {}
    }
  });
});

describe('cookie redaction — production patterns', () => {
  it('detects sensitive cookie names', () => {
    expect(SENSITIVE_COOKIE_NAME.test('session_id')).toBe(true);
    expect(SENSITIVE_COOKIE_NAME.test('auth_token')).toBe(true);
    expect(SENSITIVE_COOKIE_NAME.test('csrf-token')).toBe(true);
    expect(SENSITIVE_COOKIE_NAME.test('api_key')).toBe(true);
    expect(SENSITIVE_COOKIE_NAME.test('jwt.payload')).toBe(true);
  });

  it('ignores non-sensitive cookie names', () => {
    expect(SENSITIVE_COOKIE_NAME.test('theme')).toBe(false);
    expect(SENSITIVE_COOKIE_NAME.test('locale')).toBe(false);
    expect(SENSITIVE_COOKIE_NAME.test('_ga')).toBe(false);
  });

  it('detects sensitive cookie value prefixes', () => {
    expect(SENSITIVE_COOKIE_VALUE.test('eyJhbGciOiJIUzI1NiJ9')).toBe(true); // JWT
    expect(SENSITIVE_COOKIE_VALUE.test('sk-ant-abc123')).toBe(true); // Anthropic
    expect(SENSITIVE_COOKIE_VALUE.test('ghp_xxxxxxxxxxxx')).toBe(true); // GitHub PAT
    expect(SENSITIVE_COOKIE_VALUE.test('xoxb-token')).toBe(true); // Slack
  });

  it('ignores non-sensitive values', () => {
    expect(SENSITIVE_COOKIE_VALUE.test('dark')).toBe(false);
    expect(SENSITIVE_COOKIE_VALUE.test('en-US')).toBe(false);
    expect(SENSITIVE_COOKIE_VALUE.test('1234567890')).toBe(false);
  });
});

describe('DNS rebinding — production blocklist', () => {
  it('blocks fd00:: IPv6 metadata address via validateNavigationUrl', async () => {
    const { validateNavigationUrl } = await import('../src/url-validation');
    await expect(validateNavigationUrl('http://[fd00::]/')).rejects.toThrow(/cloud metadata/i);
  });

  it('blocks AWS/GCP IPv4 metadata address', () => {
    expect(BLOCKED_METADATA_HOSTS.has('169.254.169.254')).toBe(true);
  });

  it('does not block normal addresses', () => {
    expect(BLOCKED_METADATA_HOSTS.has('8.8.8.8')).toBe(false);
    expect(BLOCKED_METADATA_HOSTS.has('2001:4860:4860::8888')).toBe(false);
  });
});