RSA签名验证

        /// <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;
        }