Open reads format 3 (spec 29.2 to 29.7, 63 steps 17 and 18): the
PRELUDE accepts VERSION 3, and the files go to a Sink.
- Sink: Begin with the validated head, Create for each file in the
order of the head, and Commit only after every check of step 17;
after any failure that follows a successful Begin, Abort, once. A
format 3 capsule without a Sink fails right after step 2 with
ErrSinkRequired, a caller error with no code, no failed step and no
request; a capsule of format 1 or 2 without dst fails there too.
- Step 17 in its substeps: the frame and the area, security and its
verdicts, which never fail, the head, the files filling CONTENT, the
SHA-256 of each file and the padding. A failure of age or a
plaintext whose length is not P prevails; otherwise the first
substep that fails decides, and a code other than ERR_INTEGRITY is
reported only after reading PAYLOAD_AGE to its end.
- The reads of BODY grow with the bytes received, never with AREA_LEN,
HEAD_LEN or a declared size (spec 57); a test measures it.
- A failure of the Sink is the caller's own error with ERR_INTEGRITY,
as one of dst is in formats 1 and 2.
- Opened gains Head, Verdicts, AreaLen and UnusableHeadExtensions.
- Test data: "version changed" sets VERSION 4, and the format 2 list
gains "format 2 time_only relabeled format 3", which fails at step
14, as section 64 of spec v0.10 lists: 126 cases, 89 of the spec.
The randomly built capsules keep their recorded bytes.
- testkit: Build writes format 3 and can edit the padded plaintext;
Head3, Body3, DiscardSink and MemorySink build and open BODY.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
