public static bool verify(string content, string signedString, string publicKey, string input_charset)
{
bool result = false;
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;
}