Web Crypto API Cheat Sheet

async function sha256(message: string): Promise<string> {
  const encoder = new TextEncoder();
  const data = encoder.encode(message);
  
  // Compute SHA-256 buffer
  const hashBuffer = await window.crypto.subtle.digest("SHA-256", data);
  
  // Convert ArrayBuffer to Hex string
  const hashArray = Array.from(new Uint8Array(hashBuffer));
  return hashArray.map(b => b.toString(16).padStart(2, "0")).join("");
}

async function encryptAES(text: string, secretKey: CryptoKey) {
  const iv = window.crypto.getRandomValues(new Uint8Array(12)); // 96-bit IV
  const encodedText = new TextEncoder().encode(text);

  const ciphertext = await window.crypto.subtle.encrypt(
    { name: "AES-GCM", iv },
    secretKey,
    encodedText
  );

  return { ciphertext, iv };
}