Function sanitizePathKey

src/memdir/teamMemPaths.ts:22–64

* Sanitize a file path key by rejecting dangerous patterns. * Checks for null bytes, URL-encoded traversals, and other injection vectors. * Returns the sanitized string or throws PathTraversalError.

(key: string)

 * Returns the sanitized string or throws PathTraversalError.
 */
function sanitizePathKey(key: string): string {
  // Null bytes can truncate paths in C-based syscalls
  if (key.includes('\0')) {
    throw new PathTraversalError(`Null byte in path key: "${key}"`)
  }
  // URL-encoded traversals (e.g. %2e%2e%2f = ../)
  let decoded: string
  try {
    decoded = decodeURIComponent(key)
  } catch {
    // Malformed percent-encoding (e.g. %ZZ, lone %) — not valid URL-encoding,
    // so no URL-encoded traversal is possible
    decoded = key
  }
  if (decoded !== key && (decoded.includes('..') || decoded.includes('/'))) {
    throw new PathTraversalError(`URL-encoded traversal in path key: "${key}"`)
  }
  // Unicode normalization attacks: fullwidth ．．／ (U+FF0E U+FF0F) normalize
  // to ASCII ../ under NFKC. While path.resolve/fs.writeFile treat these as
  // literal bytes (not separators), downstream layers or filesystems may
  // normalize — reject for defense-in-depth (PSR M22187 vector 4).
  const normalized = key.normalize('NFKC')
  if (
    normalized !== key &&
    (normalized.includes('..') ||
      normalized.includes('/') ||
      normalized.includes('\\') ||
      normalized.includes('\0'))
  ) {
    throw new PathTraversalError(
      `Unicode-normalized traversal in path key: "${key}"`,
    )
  }
  // Reject backslashes (Windows path separator used as traversal vector)
  if (key.includes('\\')) {
    throw new PathTraversalError(`Backslash in path key: "${key}"`)
  }
  // Reject absolute paths
  if (key.startsWith('/')) {
    throw new PathTraversalError(`Absolute path key: "${key}"`)
  }
  return key
}

/**
 * Whether team memory features are enabled.