Function isPrivate

client/src/components/formHelpers/form-ip-utils.ts:15–51

(address: string)

*/

export function isPrivate(address: string) {
  // Strip `https?` prefix
  let addr = address.replace(/^https?:\/\//, '');

  // Check if localhost
  if (/^localhost:/.test(addr)) {
    return true;
  }
  // Check loopback addresses first
  if (isLoopback(addr)) {
    return true;
  }

  // Ensure the ipv4 address is valid
  if (!isV6Format(addr)) {
    const ipl = normalizeToLong(addr);
    if (ipl < 0) {
      return false;
    }
    // Normalize the address for the private range checks that follow
    addr = fromLong(ipl);
  }

  // Check private ranges
  return (
    /^(::f{4}:)?10\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
    /^(::f{4}:)?192\.168\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
    /^(::f{4}:)?172\.(1[6-9]|2\d|30|31)\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(
      addr
    ) ||
    /^(::f{4}:)?169\.254\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
    /^f[cd][0-9a-f]{2}:/i.test(addr) ||
    /^fe80:/i.test(addr) ||
    /^::1$/.test(addr) ||
    /^::$/.test(addr)
  );
}

function isLoopback(addr: string) {
  // If addr is an IPv4 address in long integer form (no dots and no colons), convert it