using System;
using System.Security.Cryptography;
using System.Text;

namespace LrGetToken
{
	/// <summary>
	/// SHA帮助类
	/// </summary>
	public class SHAHelper
	{
		/// <summary>
		/// 实现HMAC SHA256签名算法
		/// </summary>
		/// <param name="secret">加密秘钥</param>
		/// <param name="signContent">加密内容</param>
		/// <returns></returns>
		public static string HmacSHA256(string secret, string signContent)
		{
			string signRet = string.Empty;
			using (HMACSHA256 mac = new HMACSHA256(Encoding.UTF8.GetBytes(secret)))
			{
				byte[] hash = mac.ComputeHash(Encoding.UTF8.GetBytes(signContent));
				signRet = ToHexString(hash);
			}
			var hexBytes = Encoding.UTF8.GetBytes(signRet);
			return Convert.ToBase64String(hexBytes);
		}

		/// <summary>
		///  转16进制
		/// </summary>
		/// <param name="bytes"></param>
		/// <returns></returns>
		protected static string ToHexString(byte[] bytes)
		{
			string hexString = string.Empty;
			if (bytes != null)
			{
				StringBuilder strB = new StringBuilder();
				foreach (byte b in bytes)
				{
					strB.AppendFormat("{0:x2}", b);
				}
				hexString = strB.ToString();
			}
			return hexString;
		}
	}
}