Implements the encoding proposed in sigstore/architecture-docs#63
(rekor-v2-spec §6.1.4): on Rekor v2, DSSE envelopes are uploaded as a
hashedrekord whose digest covers Hash(PAE(payloadType, payload)), with
the hash derived from the signing algorithm. Rekor v1 behavior is
unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* verify, rekor: encode DSSE as hashedrekord for Rekor v2

Implements rekor-v2-spec §6.1.4: DSSE envelope entries are submitted
and verified as hashedrekord/0.0.2 with digest = Hash(PAE(payloadType,
payload)) and signature.content = envelope.signatures[0].sig.

This is vibecoded — a maintainer should take a closer look at
correctness, especially the hash-algorithm dispatch in
_hash_for_key_details and the entry-body reconstruction in
_validate_hashedrekord_v002_dsse_entry_body. Passes the draft
conformance tests in sigstore/sigstore-conformance#371.

Related spec change: sigstore/architecture-docs#63

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* verify: fix lint (import order, format, quoted annotation)

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* Add Envelope.pae() helper

Replace cross-module `_pae` imports in the Rekor v2 producer and DSSE
hashedrekord verifier with a public `Envelope.pae()` method. Addresses
review feedback on #1776: drops the cross-module use of a private symbol
and lets the hashedrekord-for-DSSE docstring read as `Hash(envelope.pae())`.

No behavior change.

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* Drop dsse/0.0.2 verifier path; replace staging test fixture

Rekor v2 will not support the dsse entry type — DSSE envelopes are
encoded as hashedrekord/0.0.2 (rekor-v2-spec §6.1.4). Remove the
now-orphaned dsse/0.0.2 dispatch branch and `_validate_dsse_v002_entry_body`
function. The dsse/0.0.1 path stays for Rekor v1 legacy bundles.

Replaces `test/assets/a.dsse.staging-rekor-v2.txt.sigstore.json` with the
`rekor2-dsse-happy-path` fixture from the sigstore-conformance
`dsse-hashedrekord-test-bundles` branch, so the staging DSSE verification
test now exercises hashedrekord/0.0.2 end-to-end.

Addresses review feedback on #1776.

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* key_details: centralize algorithm registry; use for DSSE prehash

Replace the inline hash-for-key-details mappings in verifier.py and the
hardcoded SHA-256 in client_v2.py with a single algorithm registry table
in key_details.py, matching the spec at architecture-docs/algorithm-registry.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* key_details: fix HashAlgorithm for pure Ed25519

HASH_ALGORITHM_UNSPECIFIED doesn't exist in sigstore_models; use None
instead, since _get_prehash already rejects algorithms with no prehash.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* key_details: narrow None check so mypy sees non-None hash_algorithm

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* conformance: bump sigstore-conformance to v0.0.28

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

---------

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…d-DSSE bundles

The four rekor2-dsse-* fixtures were re-signed against staging Sigstore
so their tlog entries use kind=hashedrekord/0.0.2 with
Hash(PAE(payloadType, payload)) as the recorded digest, instead of the
previous dsse/0.0.2 entries that committed to the whole envelope. This
matches the encoding described in the architecture-docs PR
sigstore/architecture-docs#63 and exercised by
the corresponding sigstore-go signing/verification changes.

Adds four new dsse-with-hashedrekord-* fixtures covering the same matrix
on Rekor v1 (kind=hashedrekord/0.0.1, signed against production Sigstore
Public Good with sigstore-go's experimental hashedrekord-over-DSSE flag
enabled), replacing the two pre-existing dsse-with-hashedrekord/ and
dsse-with-hashedrekord_fail/ dirs.

The four scenarios per family are:

  *-happy-path                : valid bundle, must verify
  *-mismatch-sig_fail         : same cert, same PAE, but envelope.sig
                                != tlog.sig (a second valid signature
                                of the same PAE was swapped in)
  *-mismatch-envelope_fail    : same cert, envelope swapped for one
                                covering a different payload so
                                Hash(PAE(envelope)) != tlog.digest
  *-invalid-sig_fail          : envelope.sig was made by an unrelated
                                key and does not verify under the
                                bundle's certificate

All bundles use the sigstore-conformance/extremely-dangerous-public-oidc-beacon
workflow identity (the suite's default in test/client.py). The rekor v2
bundles ship a custom trusted_root.json (the staging trust root); the
rekor v1 bundles use the default production trust root.

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

Implements the encoding proposed in sigstore/architecture-docs#63
(rekor-v2-spec §6.1.4): on Rekor v2, DSSE envelopes are uploaded as a
hashedrekord whose digest covers Hash(PAE(payloadType, payload)), with
the hash derived from the signing algorithm. Rekor v1 behavior is
unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

Implements the encoding proposed in sigstore/architecture-docs#63
(rekor-v2-spec §6.1.4): on Rekor v2, DSSE envelopes are uploaded as a
hashedrekord whose digest covers Hash(PAE(payloadType, payload)), with
the hash derived from the signing algorithm. Rekor v1 behavior is
unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* test/assets: regen rekor v2 DSSE bundles and add rekor v1 hashedrekord-DSSE bundles

The four rekor2-dsse-* fixtures were re-signed against staging Sigstore
so their tlog entries use kind=hashedrekord/0.0.2 with
Hash(PAE(payloadType, payload)) as the recorded digest, instead of the
previous dsse/0.0.2 entries that committed to the whole envelope. This
matches the encoding described in the architecture-docs PR
sigstore/architecture-docs#63 and exercised by
the corresponding sigstore-go signing/verification changes.

Adds four new dsse-with-hashedrekord-* fixtures covering the same matrix
on Rekor v1 (kind=hashedrekord/0.0.1, signed against production Sigstore
Public Good with sigstore-go's experimental hashedrekord-over-DSSE flag
enabled), replacing the two pre-existing dsse-with-hashedrekord/ and
dsse-with-hashedrekord_fail/ dirs.

The four scenarios per family are:

  *-happy-path                : valid bundle, must verify
  *-mismatch-sig_fail         : same cert, same PAE, but envelope.sig
                                != tlog.sig (a second valid signature
                                of the same PAE was swapped in)
  *-mismatch-envelope_fail    : same cert, envelope swapped for one
                                covering a different payload so
                                Hash(PAE(envelope)) != tlog.digest
  *-invalid-sig_fail          : envelope.sig was made by an unrelated
                                key and does not verify under the
                                bundle's certificate

All bundles use the sigstore-conformance/extremely-dangerous-public-oidc-beacon
workflow identity (the suite's default in test/client.py). The rekor v2
bundles ship a custom trusted_root.json (the staging trust root); the
rekor v1 bundles use the default production trust root.

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* test/assets: remove rekor v1 dsse-with-hashedrekord fixtures

The architecture-docs spec change scopes the dsse-hashedrekord proposal
to Rekor v2 only and drops the Rekor v1 bridge feature paragraph. These
fixtures covered the v1 bridge encoding (kind=hashedrekord/0.0.1 whose
data.hash = SHA256(PAE(payloadType, payload))) and no longer correspond
to a supported wire format. The rekor2-dsse-* fixtures (v2 path) remain.

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

* Update selftest pin for DSSE-with-hashedrekord support

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>

---------

Signed-off-by: Cody Soyland <cody.soyland@chainguard.dev>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

This is based on sigstore/architecture-docs#63
* With Rekor v2 DSSE envelopes are supported via Hashedrekord entries
  instead of a dedicated dsse entry
* digest is Hash(PAE(payloadType, payload))
* Signature is the DSSE envelope signature

This commit removes all support for the "dsse 0.0.2" entry type: this seems
ok as rekor v2 signing was never deployed in production.
* When signing with rekor v2, build a "hashedrekord 0.0.2" entry with digest
  and signature as described above
* When verifying hashedrekord, compute hash depending on bundle content
* When matching hashedrekord signatures, use envelope signatures when appropriate
* When verifying rekor entry consistency, accept a DSSE envelope with a
  "hashedrekord 0.0.2" entry

Testing:
* Implement a few new verification tests

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

* conformance: Use main HEAD for testing

The new DSSE-as-hashedrekord tests have not yet been released

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

* Rekor2: Support DSSE via Hashedrekord entries

This is based on sigstore/architecture-docs#63
* With Rekor v2 DSSE envelopes are supported via Hashedrekord entries
  instead of a dedicated dsse entry
* digest is Hash(PAE(payloadType, payload))
* Signature is the DSSE envelope signature

This commit removes all support for the "dsse 0.0.2" entry type: this seems
ok as rekor v2 signing was never deployed in production.
* When signing with rekor v2, build a "hashedrekord 0.0.2" entry with digest
  and signature as described above
* When verifying hashedrekord, compute hash depending on bundle content
* When matching hashedrekord signatures, use envelope signatures when appropriate
* When verifying rekor entry consistency, accept a DSSE envelope with a
  "hashedrekord 0.0.2" entry

Testing:
* Implement a few new verification tests

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

* sign: Only allow 1 signature in DSSE envelope

As per specification

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

---------

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>