v4.2.0: full (pure) post-quantum mode + critical dedup nonce fix

Add a native full post-quantum encryption mode and fix a critical
keystream-reuse bug in deduplicated encrypted archives.

Full post-quantum mode (--pq-only)
- New envelope type 0x06 (ZUPT_ENC_PQ_ONLY): ML-KEM-768 (FIPS 203) as
  the sole key-establishment mechanism, with no classical X25519
  component. Archive key = SHA3-512(ml_ss || ml_ct || "ZUPT-PQ-ONLY-v1").
- For compliance postures that require a single NIST-standardised PQ
  primitive with no classical KEM in the envelope (CNSA 2.0-style
  "PQ-only"). Hybrid --pq stays the recommended default; --pq-only has
  no classical fallback, so a break of ML-KEM-768 alone breaks it.
- keygen --pq-only / keygen --pub --pq-only (ZPQK magic, 1200B pub /
  3600B priv; not interchangeable with hybrid --pq keys). Wrong or
  tampered ciphertext is rejected via ML-KEM FO implicit rejection plus
  the HMAC-SHA256 Encrypt-then-MAC envelope. In-tree, default build.

Security (critical): AES-256-CTR keystream reuse under --dedup
- Dedup assigns block sequence 0 to every data block (the sentinel that
  keeps cross-file dedup references authenticating consistently). The
  per-block nonce was base_nonce XOR block_seq, so under --dedup every
  block collapsed to the same nonce, reusing the CTR keystream across
  distinct plaintexts (a many-time-pad). Each block now uses a fresh
  random 128-bit nonce stored in the block prefix and bound into the
  block MAC; block_seq is still bound as MAC AAD. Regression test:
  tests/test_dedup_nonce.sh. Re-encrypt any --dedup encrypted archives
  written by <= 4.1.0.

Other
- keygen --sdk / --box on a source-only build now fails with a clear
  message pointing to native --pq / --pq-only (or a WITH_SDK=1 build).
- Documentation: README, SECURITY, THREAT_MODEL, man page, CHANGELOG,
  and all packaging recipes updated for the new mode and the security
  fix; version bumped to 4.2.0. Wire format v1.6 unchanged (0x06 is
  additive).

Validation: make check 16/16, quick suite 11/11 (incl. PQ-only),
dedup-nonce regression (all block nonces distinct), cppcheck clean.

packaging/opensuse/README.md

@@ -1,12 +1,12 @@
 # openSUSE Build Service update for `home:cabelo:innovators/vaptvupt`
 
-This directory contains the three files needed to build vaptvupt `4.1.0`
+This directory contains the three files needed to build vaptvupt `4.2.0`
 in OBS:
 
 | File          | Purpose                                                                 |
 |---------------|-------------------------------------------------------------------------|
-| `_service`    | `revision` pinned to `v4.1.0`. Format unchanged (still `tar_scm`).      |
-| `vaptvupt.spec`   | `Version: 4.1.0`. `License: AGPL-3.0-or-later`. `%check` calls `make check`. |
+| `_service`    | `revision` pinned to `v4.2.0`. Format unchanged (still `tar_scm`).      |
+| `vaptvupt.spec`   | `Version: 4.2.0`. `License: AGPL-3.0-or-later`. `%check` calls `make check`. |
 | `vaptvupt.changes`| Changelog for the 4.x series. Older history preserved verbatim.        |
 
 ## Spec notes
@@ -58,22 +58,22 @@ cp /path/to/vaptvupt-source/packaging/opensuse/_service     .
 cp /path/to/vaptvupt-source/packaging/opensuse/vaptvupt.spec    .
 cp /path/to/vaptvupt-source/packaging/opensuse/vaptvupt.changes .
 
-# 3. Trigger the service locally to fetch v4.1.0 from GitHub
+# 3. Trigger the service locally to fetch v4.2.0 from GitHub
 osc service runall
-# Produces vaptvupt-4.1.0.tar.gz in the current directory.
+# Produces vaptvupt-4.2.0.tar.gz in the current directory.
 
 # 4. (Optional) Local build to verify before committing
 osc build openSUSE_Tumbleweed x86_64
 
 # 5. Commit upstream
-osc status   # confirm vaptvupt-4.1.0.tar.gz is staged alongside the
+osc status   # confirm vaptvupt-4.2.0.tar.gz is staged alongside the
              # three text files
-osc commit -m "Update to 4.1.0"
+osc commit -m "Update to 4.2.0"
 ```
 
 ## Notes for future updates
 
-* The `_service` `revision` is pinned to `v4.1.0`. To track a new
+* The `_service` `revision` is pinned to `v4.2.0`. To track a new
   release, edit that one line and re-run `osc service runall`.
 * The spec's `Version:` field is hard-coded — when you bump `_service`
   `revision`, also bump `Version:` to match.

packaging/opensuse/_service

@@ -2,7 +2,7 @@
         <service name="tar_scm" mode="manual">
                 <param name="url">https://github.com/cristiancmoises/zupt</param>
                 <param name="scm">git</param>
-                <param name="revision">v4.1.0</param>
+                <param name="revision">v4.2.0</param>
                 <param name="versionformat">@PARENT_TAG@</param>
                 <param name="versionrewrite-pattern">v(.*)</param>
                 <param name="submodules">enable</param>

packaging/opensuse/vaptvupt.changes

@@ -1,3 +1,26 @@
+-------------------------------------------------------------------
+Wed Jul  9 12:00:00 UTC 2026 - Alessandro de Oliveira Faria <cabelo@opensuse.org>
+
+- Update to 4.2.0:
+  * New native full (pure) post-quantum mode --pq-only: ML-KEM-768
+    (FIPS 203) as the sole key-establishment mechanism, with no
+    classical X25519 component (envelope type 0x06; archive key
+    SHA3-512(ml_ss || ml_ct || "ZUPT-PQ-ONLY-v1")). For compliance
+    postures that mandate a single NIST-standardised PQ primitive with
+    no classical KEM in the envelope (CNSA 2.0-style "PQ-only"). Keys
+    via keygen --pq-only. In-tree crypto, built in the default
+    source-only package. Hybrid --pq remains the recommended default;
+    --pq-only has no classical fallback.
+  * Security (critical): fixed AES-256-CTR keystream reuse under
+    --dedup. Dedup blocks all use sequence 0, so the previous nonce
+    (base_nonce XOR seq) collapsed to a single value across blocks,
+    reusing the CTR keystream. Each block now uses a fresh random
+    128-bit nonce. Re-encrypt any --dedup encrypted archives written
+    by <= 4.1.0.
+  * keygen --sdk / --box now gives clear guidance toward native --pq /
+    --pq-only on a source-only build.
+  * Wire format v1.6 unchanged; the 0x06 envelope is additive.
+
 -------------------------------------------------------------------
 Tue Jul  7 12:00:00 UTC 2026 - Alessandro de Oliveira Faria <cabelo@opensuse.org>
 

packaging/opensuse/vaptvupt.spec

@@ -19,7 +19,7 @@
 
 
 Name:           vaptvupt
-Version:        4.1.0
+Version:        4.2.0
 Release:        0
 Summary:        Post-quantum backup compression with AES-256 + ML-KEM-768 hybrid encryption
 License:        AGPL-3.0-or-later