OID to Hex Converter

Convert an object identifier between its dotted form and its DER bytes, in either direction. 1.2.840.10045.3.1.7 encodes to 06 08 2a 86 48 ce 3d 03 01 07 and back, and known OIDs are named. The first two arcs share one value, which is why 2.100.3 does not start with a single byte.