static public string ToOid (ASN1 asn1)
{
if (asn1 == null)
throw new ArgumentNullException ("asn1");
byte[] aOID = asn1.Value;
StringBuilder sb = new StringBuilder ();
// Pick apart the OID
byte x = (byte) (aOID[0] / 40);
byte y = (byte) (aOID[0] % 40);
if (x > 2) {
// Handle special case for large y if x = 2
y += (byte) ((x - 2) * 40);
x = 2;
}
sb.Append (x.ToString (CultureInfo.InvariantCulture));
sb.Append (".");
sb.Append (y.ToString (CultureInfo.InvariantCulture));
ulong val = 0;
for (x = 1; x < aOID.Length; x++) {
val = ((val << 7) | ((byte) (aOID [x] & 0x7F)));
if ( !((aOID [x] & 0x80) == 0x80)) {
sb.Append (".");
sb.Append (val.ToString (CultureInfo.InvariantCulture));
val = 0;
}
}
return sb.ToString ();
}