code-canvas-server

export type LicensePayload = {
  githubId: string;
  plan: "pro";
  generation: "new" | "legacy";
  canUseV2: boolean;
  canUseLegacy: boolean;
  issuedAt: number; // epoch seconds
  expiresAt: number; // epoch seconds (issuedAt + 14 days)
  tokenId: string; // UUID
};

export const LICENSE_TOKEN_COOKIE_NAME = "cc_license_token";
export const LICENSE_TTL_SECONDS = 14 * 24 * 60 * 60; // 14 days
export const LICENSE_GRACE_SECONDS = 3 * 24 * 60 * 60; // 3 days

export const LICENSE_PUBLIC_KEY_PEM = `-----BEGIN PUBLIC KEY-----
MCowBQYDK2VwAyEAausrQ9PqJtbbKXd5RcYYF1oRWtu3p38GXqNDF3r5FVk=
-----END PUBLIC KEY-----`;

function base64UrlDecode(str: string): Uint8Array {
  // Convert base64url to base64
  let base64 = str.replace(/-/g, "+").replace(/_/g, "/");
  while (base64.length % 4 !== 0) {
    base64 += "=";
  }
  const binary = atob(base64);
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i++) {
    bytes[i] = binary.charCodeAt(i);
  }
  return bytes;
}

export function base64UrlEncode(bytes: Uint8Array): string {
  let binary = "";
  for (let i = 0; i < bytes.length; i++) {
    binary += String.fromCharCode(bytes[i]!);
  }
  return btoa(binary).replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
}

export function parseLicenseToken(
  token: string
): {
  payload: LicensePayload;
  payloadRaw: Uint8Array;
  signature: Uint8Array;
} | null {
  const dotIndex = token.indexOf(".");
  if (dotIndex < 0) return null;
  const payloadB64 = token.slice(0, dotIndex);
  const signatureB64 = token.slice(dotIndex + 1);
  try {
    const payloadBytes = base64UrlDecode(payloadB64);
    const signatureBytes = base64UrlDecode(signatureB64);
    const payload = JSON.parse(
      new TextDecoder().decode(payloadBytes)
    ) as LicensePayload;
    return { payload, payloadRaw: payloadBytes, signature: signatureBytes };
  } catch {
    return null;
  }
}