static byte[] PEM (string type, byte[] data)
{
string pem = Encoding.ASCII.GetString (data);
string header = String.Format ("-----BEGIN {0}-----", type);
string footer = String.Format ("-----END {0}-----", type);
int start = pem.IndexOf (header) + header.Length;
int end = pem.IndexOf (footer, start);
string base64 = pem.Substring (start, (end - start));
return Convert.FromBase64String (base64);
}