What the update of the documentation found without a test: Header.UnusableNote
and the notice of decrypt, the helper that keeps a panic of a parser of
security in its own part, and that EncryptFiles writes nothing of the
capsule while it waits for a signature (spec 62.1 rules 19 and 25). The
usage text of decrypt -expect-author says that it writes no file.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The reference moves to the DateKeys Protocol Specification v0.9, approved
by its author on 29 September 2026. Encrypt writes capsule format 2 only;
Open and Inspect read formats 1 and 2, and a format 1 capsule keeps the
verdict v0.8.2 gave it.
Format 2 (spec §22, §29.1, §31, §39):
- VERSION in the PRELUDE is the capsule format, capsule.Format; any other
value is ERR_UNSUPPORTED_VERSION at step 2.
- CONTROL_CBOR has the schema version of its format. Version 2 adds key 6,
payload_length (8 bytes, big-endian, at most L_MAX = 2^53 - 2^46), and
key 7, padding (1 bloque256, 2 reforzado); it is 103 bytes without
extensions, whatever L.
- The payload is the content padded with zeros to P = rule(L). Step 17
checks the length and the zeros, and Open writes only the first L bytes.
- INNER_ACCESS_AGE holds exactly 16 X25519 stanzas: 1 to 16 credentials,
and a dummy in each slot left, in a uniformly random order.
Writer rules (spec §62.1): EncryptOptions.Length is required and the
source must deliver exactly that many bytes; recipients that are not
canonical or of low order are rejected (agewrap.CheckX25519Recipient);
self-checks of the header, the control, INNER_ACCESS_AGE and PAYLOAD_AGE.
The CLI measures its input, takes -padding and reports the format.
Test data: seven format 2 fixtures, padding vectors checked against
math/big, format 2 CBOR vectors, and the mutation corpus in both formats
with the 22 cases of the third list of spec §64, built without randomness
by sealing the fixtures again with their known keys and nonces. The
format 1 fixtures are kept byte for byte and never regenerated; the
differential corpus keeps its 1825 cases and adds a block per format 2
fixture. The spec copy loses its "to be implemented" markers, and the
READMEs, CHANGELOG, traceability and testdata/README.md follow v0.9.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Step 2b: package codec is rewritten without reflection or struct tags. A
strict Decoder accepts only the spec §58 profile, Unmarshal decodes,
re-encodes and compares, Peek reads the type tag and version, and Walk is a
bounded iterative helper for vectors and fuzzing. Every schema has its own
hand-written encoder and decoder that checks all CDDL rules before the
fields with their own error codes. github.com/fxamacker/cbor/v2 and
github.com/x448/float16 are gone; nothing replaces them. Valid objects
encode and decode exactly as before (1.34 million differential verdicts);
the invalid-input differences are documented in CHANGELOG and
traceability decision 12. A review found and fixed an access_policy check
that truncated to uint8.
Step 3: testdata gains vectors/cbor.json (generic and per-schema CBOR
vectors), vectors/mutations.json (the 55-case mutation corpus, replayable
offline), vectors/inspect_differential.json (1,825 fixed-seed mutations
with the Go verdict) and one inspect -json golden per fixture, all
regenerated byte-identically by genfixtures and documented in
testdata/README.md for second implementations.
Gate green with 90 s of fuzzing per target on all 15 targets; codec at
100 % coverage; pre-existing testdata byte-identical.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>