A valid seal is S4 only when its token carries accuracy and t plus the
accuracy is before round_time; otherwise S5, whose text gives the reason,
the first that holds: sealed after or too close, no accuracy under the BTSP
policy of ETSI EN 319 421 (0.4.0.2023.1.1), or no accuracy (spec v0.16,
29.7, 29.11). The line of a signer of F6 whose seal does not prove it says
so with the same reason. cms.Token gains HasAccuracy, Policy and BTSP;
Verdicts gain SealReason and SignerLine.Reason; EncryptFiles returns the
verdicts of the area it wrote in Result.Security, so that a writer warns of
a seal without accuracy (rule 19).
security_cms.json is made again: 143 cases, the seals about something else
with an accuracy of a second, and the new cases of 64 with seal_reason.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The review found that genfixtures -force rewrote the five fixtures of
format 3 of v0.10 with the area of 32 KiB and then failed, leaving testdata
half done. EncryptFiles takes TestAreaLen, only with TestVectors, as Encrypt
takes TestVectors for format 2 (spec 62.1 rules 1 and 13), and the
generator gives those fixtures their area of 512 bytes: -force now
regenerates them with the same L and P.
- format3_seal_unsupported uses seal_type 4294967295, reserved for tests,
as spec 67 says, instead of seal_type 1, which a later version may
define; capsule.AlgTest and SealTypeTest name the two values.
- format3_unsigned: the capsule of format3_signed without its signature,
with the area of 32 KiB: the same P (spec 64).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The TSTInfo is read field by field in DER, with accuracy from zero and
millis and micros from 1 to 999, genTime in UTC with Z, no default written
and nothing after the last field. The ContentInfo and the SignerInfo must be
SEQUENCEs, a SignerInfo version must match its sid, an attribute needs a
value and is counted by attribute and not by value, a signing-certificate
beside the v2 decides nothing, PSS parameters come in order without the
trailer, and der.Check refuses the end of contents and the universal tags
the profile does not use.
The writer signs before L is fixed: write asks prepare for the final L, so
the area grows to 64 KiB only when what was signed does not fit and LargeArea
allows it, and nobody signs twice for it. Typed nils are nil, the exclusions
are checked before a file is read, Encrypt refuses the signing options, and
EvaluateSecurityIn gives X if a parser panics. The issuer of a certificate is
filtered like its holder.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
The reader evaluates a signature of alg 2 (F1, F2, F5, F6, with the signers
named) and a seal of seal_type 2 (S1 to S5) in the context of the capsule,
with SIGNERS in strictly ascending order of certificate hashes. The writer
takes a CMSSigner, which gets AUTHOR_MESSAGE and returns what the person
signed outside, and a Sealer, which asks an authority for the token over
SEAL_SUBJECT; it checks the result with the rules of the reader and writes
nothing unless every required signer is valid and sealed.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
AreaLen is 32 KiB, and LargeArea asks for 64 KiB. EncryptOptions.AuthorKey
signs inside sealer.write, through a prepare hook that gets the final
control: SECURITY_CBOR and the frame are built and evaluated with the rules
of the reader before anything is written. OpenOptions.AuthorKeys feeds
EvaluateSecurityIn from openBody with control_commit, head_digest and the
round time: F4, F3 with a saved key, F2 when it does not verify.
The fixtures of v0.10 keep the area of 512 (AreaUnit). The two
"unsupported" fixtures use alg 4294967295, since a random alg 1 is now F2.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
capsule/signature.go has what an author signs and a seal seals, as the
spec v0.11 draft defines it (29.8, 29.11): payload_commit, control_commit
over CONTROL_SIG, without I_PAYLOAD and with L at zero, head_digest,
signers_digest, AUTHOR_MESSAGE as ASCII text of 99 bytes with its code,
SIG_PART over the exact content of key 2, and SEAL_SUBJECT.
EvaluateSecurityIn checks a signature of alg 1 with the strict profile in
the context of a capsule: F4, or F3 with a key the person saved; F2 when
it does not verify; F1 without context, as in v0.10, and for alg 2, not
yet implemented. Verdicts carries the key and the label for the texts.
Not wired yet: the writer does not sign and still writes the area of 512
bytes, and the reader still calls EvaluateSecurity without context. The
handoff of docs lists what is left.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
EncryptFiles writes format 3 (spec 29.2 to 29.6, 61, 62, 62.1): the
files of a list of Sources, each read twice, with the comment and the
declared author.
- Before anything is written: the paths and the texts are checked with
the rules of the reader, in the words of a writer, naming the rule
and the character, and the two paths of an R7 collision (rule 15);
the comment has its CR LF and lone CR turned into LF (29.6); L is
measured with a head whose salt and SHA-256 are zero, as long as the
final one, and the first reading hashes each file, which must have
exactly its Size.
- The files go in the byte order of their paths (R8), whatever the
order of the Sources; the mtime is kept only from 1970 to 9999,
never clipped (rule 16); at least one file or a comment (rule 14).
- The head, with a fresh salt, the control and the security area are
decoded with the rules of the reader before sealing (rule 17), and
the frame is checked against L. The area is 512 bytes with the
empty security, whatever the options (rule 13).
- The second reading writes each file into PAYLOAD_AGE and fails if its
size or SHA-256 changed (rule 18).
- Encrypt and EncryptFiles share the sealing; Encrypt writes format 2
only with the new TestVectors option (rule 1), and takes no head.
The test data generators set it, and so does the CLI until step 5
moves it to EncryptFiles.
- Result.Head is the head written. DecodeHead keeps the check of the
critical extensions apart, so that the self-check decodes the head
as the one of the control does.
- The examples and the live test write with EncryptFiles.
- The reader tests had a literal U+202E, now escaped.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
dev