HmacSHA256

因为C#的byte是无符号类型，取值范围为0~255，java的byte类型是有符号类型，取值为-128~127，当ComputeHash获取到hash值后，需要判断byte是否小于等于127,如果满足条件则取当前值，否则就使用当前值(byte)减去256

C# 实现

/// <summary>
/// hmacSHA256加密实现
/// </summary>
/// <returns>The token.</returns>
/// <param name="secret">Secret.</param>
/// <param name="signKey">加密参数</param>
// ReSharper disable once InconsistentNaming
public static string HmacSHA256Encrypt(string secret, string signKey)
{
    using (var mac = new HMACSHA256(Encoding.UTF8.GetBytes(signKey)))
    {
        mac.Initialize();
        var hash = mac.ComputeHash(Encoding.UTF8.GetBytes(secret));
        var sb = new sbyte[hash.Length];
        for (var i = 0; i < hash.Length; i++)
        {
            // 语言差异导致结果不同 此处做处理
            sb[i] = hash[i] <= 127 ? (sbyte)hash[i] : (sbyte)(hash[i] - 256);
        }
        var unsignedByteArray = (byte[])(Array)sb;

        // 直接base64编码
        //return Convert.ToBase64String(unsignedByteArray);

        // 先转16进制 再base64编码
        return Convert.ToBase64String(Encoding.UTF8.GetBytes(ToHex(unsignedByteArray)));
    }
}

---

转 Hex 字符

/// <summary>
/// 字节数组转换为Hex字符串
/// </summary>
/// <param name="data"></param>
/// <param name="toLowerCase"></param>
/// <returns></returns>
public static string ToHex(byte[] data, bool toLowerCase = true)
{
    var hex = BitConverter.ToString(data).Replace("-", string.Empty);
    return toLowerCase ? hex.ToLower() : hex.ToUpper();
}

Java 实现

    public static void main(String[] args) {
        try {
            // url 为调用相关接口的地址
            String url = "www.domain.com";
            String signSource = "POST".concat(url);
            String timeStamp = String.valueOf(System.currentTimeMillis());
            String secretId = "165161616165";
            String stringToSign = secretId + timeStamp + signSource;
            String secretKey ="!secretKey";
            //HmacSHA256算法
            Mac mac;
            mac = Mac.getInstance("HmacSHA256");
            mac.init(new SecretKeySpec(secretKey.getBytes("UTF-8"), "HmacSHA256"));
            byte[] signatureBytes = mac.doFinal(stringToSign.getBytes("UTF-8"));
            String hexStr = Hex.encodeHexString(signatureBytes);
            String signature = Base64.encodeBase64String(hexStr.getBytes());

            //Postman调用的header
            System.out.println("sign: "+ signature);
            System.out.println("timeStamp: " + timeStamp);
            System.out.println("secretId: " + secretId);

        } catch (NoSuchAlgorithmException | InvalidKeyException | UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }