The certificate is in ASN.1 DER binary encoding. This encoding consists of records in the following sequence:
type tag, length, data.
The type tag contains the following information:
- type class (2 bits): universal, application, context-specific, or private
- constructed (1 bit): set if the record consists of smaller records
- type (5 bits): if type class is universal then type indicates integer, ASCII string, Object ID, etc.