/**
 * Compare fixed-format cryptographic values without data-dependent early exit.
 *
 * Length remains observable, so callers should validate public wire formats
 * first. Peach's keys and tokens have fixed lengths at every authenticated
 * comparison site.
 */
export function constantTimeEqualBytes(
  left: Uint8Array,
  right: Uint8Array,
): boolean {
  let difference = left.length ^ right.length;
  const length = Math.max(left.length, right.length);
  for (let index = 0; index < length; index += 1) {
    difference |= (left[index] ?? 0) ^ (right[index] ?? 0);
  }
  return difference === 0;
}

export function constantTimeEqualHex(left: string, right: string): boolean {
  return constantTimeEqualBytes(
    new TextEncoder().encode(left.toLowerCase()),
    new TextEncoder().encode(right.toLowerCase()),
  );
}