5.2.3.
Version 4 Signature Packet Format
The body of a version 4 Signature Packet contains:
- One-octet version number (4).
- One-octet signature type.
- One-octet public key algorithm.
- One-octet hash algorithm.
- Two-octet scalar octet count for following hashed subpacket data. Note that this is the length in octets of all of the hashed subpackets; a pointer incremented by this number will skip over the hashed subpackets.
- Hashed subpacket data. (zero or more subpackets)
- Two-octet scalar octet count for following unhashed subpacket data. Note that this is the length in octets of all of the unhashed subpackets; a pointer incremented by this number will skip over the unhashed subpackets.
- Unhashed subpacket data. (zero or more subpackets)
- Two-octet field holding left 16 bits of signed hash value.
- One or more multi-precision integers comprising the signature.
