SubtleCrypto: digest() メソッド

digest(algorithm, data)

const text =
  "An obscure body in the S-K System, your majesty. The inhabitants refer to it as the planet Earth.";

async function digestMessage(message) {
  const encoder = new TextEncoder();
  const data = encoder.encode(message);
  const hash = await crypto.subtle.digest("SHA-256", data);
  return hash;
}

digestMessage(text).then((digestBuffer) =>
  console.log(digestBuffer.byteLength),
);

const text =
  "An obscure body in the S-K System, your majesty. The inhabitants refer to it as the planet Earth.";

async function digestMessage(message) {
  const msgUint8 = new TextEncoder().encode(message); // (utf-8 の) Uint8Array にエンコードする
  const hashBuffer = await crypto.subtle.digest("SHA-256", msgUint8); // メッセージをハッシュする
  const hashArray = Array.from(new Uint8Array(hashBuffer)); // バッファーをバイト列に変換する
  const hashHex = hashArray
    .map((b) => b.toString(16).padStart(2, "0"))
    .join(""); // バイト列を 16 進文字列に変換する
  return hashHex;
}

digestMessage(text).then((digestHex) => console.log(digestHex));