ExtractHotstuffExtra extracts all values of the HotstuffExtra from the header.

HotstuffFilteredHeader returns a filtered header which some information (like seal, committed seals) are clean to fulfill the Istanbul hash rules.

ErrInvalidHotstuffHeaderExtra is returned if the length of extra-data is less than 32 bytes.

HotstuffDigest represents a hash of "Hotstuff practical byzantine fault tolerance" to identify whether the block is from Istanbul consensus engine.

Fixed number of extra-data bytes reserved for validator seal.

Fixed number of extra-data bytes reserved for validator vanity.