C#通过安全证书生成签名和验签辅助类

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace TestEPS
{
    public static class bangzhu
    {

      private static string prikeyPath = "D:\\testMer.key.der";
      private static string pubkeyPath = "D:\\testUmpay.cert.crt";
        //private static string prikeyPath = @"E:\证书地址.der";
        //private static string pubkeyPath = @"E:\证书.crt";

        //用私钥生成签名
        public static string sign(string unsign)
        {
            string prikey = DecodeDERKey(prikeyPath);
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            try
            {
                rsa.FromXmlString(prikey);

            }
            catch (Exception ex)
            {
                return "";
            }
            // 加密对象 
            RSAPKCS1SignatureFormatter f = new RSAPKCS1SignatureFormatter(rsa);
            f.SetHashAlgorithm("SHA1");
            //把要签名的源串转化成字节数组
            byte[] source = System.Text.UnicodeEncoding.Default.GetBytes(unsign);
            SHA1Managed sha = new SHA1Managed();
            //对签名源串做哈昔算法,为sha1.
            byte[] result = sha.ComputeHash(source);
            string s = Convert.ToBase64String(result);
            Console.WriteLine(s);
            //对哈昔算法后的字符串进行签名.
            byte[] b = f.CreateSignature(result);
            //生长签名对象sign
            string sign = Convert.ToBase64String(b);
            return sign;

        }
        //用公钥进行签名的验证
        public static bool verify(string unsign, string sign)
        {
            string pubkey = pathToXMLKey(pubkeyPath);
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(pubkey);
            //实例化验签对象.