Function decryptWithDataKey

packages/consortium-web/src/lib/encryption.ts:163–185

(
  bundle: Uint8Array,
  dataKey: Uint8Array,
)

}

export async function decryptWithDataKey(
  bundle: Uint8Array,
  dataKey: Uint8Array,
): Promise<unknown | null> {
  if (bundle.length < 1 || bundle[0] !== 0) return null;
  if (bundle.length < 13 + 16) return null;

  const nonce = bundle.slice(1, 13);
  // SubtleCrypto expects authTag appended to ciphertext
  const ciphertextWithTag = bundle.slice(13);

  try {
    const key = await getAesKey(dataKey);
    const decrypted = await crypto.subtle.decrypt(
      { name: 'AES-GCM', iv: toArrayBuffer(nonce) },
      key,
      toArrayBuffer(ciphertextWithTag),
    );
    return JSON.parse(new TextDecoder().decode(decrypted));
  } catch {
    return null;
  }
}

// --- Unified encrypt/decrypt ---