在base64中生成WebCrypto签名

// 生成密钥对
crypto.subtle.generateKey(
  {
    name: 'RSASSA-PKCS1-v1_5',
    modulusLength: 2048,
    publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
    hash: 'SHA-256',
  },
  true,
  ['sign', 'verify']
)
.then((keyPair) => {
  // 导出公钥
  return crypto.subtle.exportKey('jwk', keyPair.publicKey);
})
.then((exportedPublicKey) => {
  // 使用私钥生成签名
  const data = 'Hello, World!';
  const encoder = new TextEncoder();
  const encodedData = encoder.encode(data);

  return crypto.subtle.sign(
    {
      name: 'RSASSA-PKCS1-v1_5',
    },
    keyPair.privateKey,
    encodedData
  );
})
.then((signature) => {
  // 导出签名为base64编码的字符串
  const base64Signature = btoa(String.fromCharCode.apply(null, new Uint8Array(signature)));

  console.log('WebCrypto签名:', base64Signature);
})
.catch((error) => {
  console.error('生成WebCrypto签名时出错:', error);
});