public static string sign(string content, string privateKey, string input_charset)
{
Encoding code = Encoding.GetEncoding(input_charset);
byte[] Data = code.GetBytes(content);
RSACryptoServiceProvider rsa = DecodePemPrivateKey(privateKey);
SHA1 sh = new SHA1CryptoServiceProvider();
byte[] signData = rsa.SignData(Data, sh);
return Convert.ToBase64String(signData);
}
/// <summary>