/// <summary>

        /// 验证签名

        /// </summary>

        /// <param name="content">待签名字符串</param>

        /// <param name="signedString">POST过来的签名</param>

        /// <param name="publicKey">公钥</param>

        /// <param name="input_charset">编码格式</param>

        /// <returns></returns>

        public static bool verify(string content, string signedString, string publicKey, string input_charset)

        {

            bool result = false;

            try

            {

                Encoding code = Encoding.GetEncoding(input_charset);

                byte[] Data = code.GetBytes(content);

                byte[] data = Convert.FromBase64String(signedString);

                RSAParameters paraPub = ConvertFromPublicKey(publicKey);

                RSACryptoServiceProvider rsaPub = new RSACryptoServiceProvider();

                rsaPub.ImportParameters(paraPub);

                SHA1 sh = new SHA1CryptoServiceProvider();

                result = rsaPub.VerifyData(Data, sh, data);

                return result;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

   #region 解析.net 生成的Pem

        private static RSAParameters ConvertFromPublicKey(string pemFileConent)

        {

            byte[] keyData = Convert.FromBase64String(pemFileConent);

            if (keyData.Length < )

            {

                throw new ArgumentException("pem file content is incorrect.");

            }

            byte[] pemModulus = new byte[];

            byte[] pemPublicExponent = new byte[];

            Array.Copy(keyData, , pemModulus, , );

            Array.Copy(keyData, , pemPublicExponent, , );

            RSAParameters para = new RSAParameters();

            para.Modulus = pemModulus;

            para.Exponent = pemPublicExponent;

            return para;

        }