func signData(gamePrivateKey, content string) (string, error) {
	privateKeyPEM := fmt.Sprintf("-----BEGIN PRIVATE KEY-----\n%s\n-----END PRIVATE KEY-----", gamePrivateKey)

	block, _ := pem.Decode([]byte(privateKeyPEM))
	if block == nil {
		return "", fmt.Errorf("failed to decode PEM block containing private key")
	}

	privateKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return "", fmt.Errorf("failed to parse private key: %v", err)
	}

	rsaPrivateKey, ok := privateKey.(*rsa.PrivateKey)
	if !ok {
		return "", fmt.Errorf("not an RSA private key: %v", err)
	}

	// 计算SHA256哈希
	hashed := sha256.Sum256([]byte(content))
	// 使用RSA PSS进行签名
	signature, err := rsa.SignPSS(rand.Reader, rsaPrivateKey, crypto.SHA256, hashed[:], 
	   // 默认使用的是PSSSaltLengthAuto，需要修改为PSSSaltLengthEqualsHash，不然会报{"rtnCode":1,"errMsg":"Check sign failed"}
		&rsa.PSSOptions{
			SaltLength: rsa.PSSSaltLengthEqualsHash,
			Hash:       crypto.SHA256,
	})

	return base64.StdEncoding.EncodeToString(signature), nil
}