private static byte[] DoDecryptBytes(string input, SysCrypt.RSACryptoServiceProvider rsa)
{
try
{
int b64bs = (rsa.KeySize / 8 / 3 * 4) + ((rsa.KeySize / 8 % 3) != 0 ? 4 : 0);
List<byte> res = new List<byte>();
for (int i = 0; i < input.Length / b64bs; i++)
res.AddRange(rsa.Decrypt(Convert.FromBase64String(input.Substring(i * b64bs, b64bs)), true));
return res.ToArray();
}
catch { return null; }
}
private static string DoEncrypt(string input, SysCrypt.RSACryptoServiceProvider rsa)
{
if (input == null) return null;
byte[] bytes = Encoding.UTF8.GetBytes(input);
//int utf8bs = (rsa.KeySize / 8) - 2 - (2 * SysCrypt.SHA1.Create().ComputeHash(bytes).Length);
int utf8bs = (rsa.KeySize / 8) - 42;
int iterat = bytes.Length / utf8bs;
StringBuilder sb = new StringBuilder();
for (int i = 0; i <= iterat; i++)
{
byte[] result = rsa.Encrypt(bytes.Skip(i * utf8bs).Take(utf8bs).ToArray(), true);
//Array.Reverse(result);
sb.Append(Convert.ToBase64String(result));
}
return sb.ToString();
}
private static string DoDecrypt(string input, SysCrypt.RSACryptoServiceProvider rsa)
{
try
{
return Encoding.UTF8.GetString(DoDecryptBytes(input,rsa));
}
catch { return null; }
}