start-os/core/startos/src/s9pk/v2/specv2.md

Magic

0x3b3b

Version

0x02 (varint)

Merkle Archive

Header

• ed25519 pubkey (32B)
• ed25519 signature of TOC sighash (64B)
• TOC sighash: (32B)
• TOC position: (8B: u64 BE)
• TOC size: (8B: u64 BE)

TOC

• number of entries (varint)
• FOREACH section
  • name (varstring)
  • hash (32B: BLAKE-3 of file contents / TOC sighash)
  • TYPE (1B)
    • TYPE=MISSING (0x00)
    • TYPE=FILE (0x01)
      • position (8B: u64 BE)
      • size (8B: u64 BE)
    • TYPE=TOC (0x02)
      • position (8B: u64 BE)
      • size (8B: u64 BE)

SigHash

Hash of TOC with all contents MISSING

FILE

<File contents>

Example

foo/bar/baz.txt

ROOT TOC:

• 1 section
  • name: foo hash: sighash('a) type: TOC position: 'a length: _

'a:

• 1 section
  • name: bar hash: sighash('b) type: TOC position: 'b size: _

'b:

• 2 sections
  • name: baz.txt hash: hash('c) type: FILE position: 'c length: _
  • name: qux hash: <unverifiable> type: MISSING

'c: <CONTENTS OF baz.txt>

"foo/" hash: _ size: 15b

"bar.txt" hash: _ size: 5b

<CONTENTS OF foo/> ( "baz.txt" hash: _ size: 2b ) <CONTENTS OF bar.txt> ("hello") <CONTENTS OF baz.txt> ("hi")