Adds a new "Digital signature properties" doorhanger to the pdf.js
toolbar that lists every digital signature found in the opened PDF,
verifies each one (via NSS in the Firefox build through a new chrome
bridge), and shows per-signature status + certificate state.
The viewer side parses /Sig dicts in the worker
(`PDFDocument.signatures`), strict-validates the /ByteRange offsets
before slicing, and ships only signature metadata across the worker
boundary. The PKCS#7 blob and signed-data byte spans live in a
worker-side map and are fetched lazily one signature at a time via
a new `getSignatureData(id)` RPC, immediately before verification
runs, so the bytes never sit in main-thread memory for the
document's lifetime.
The panel is feature-gated by `pdfjs.enableSignatureVerification`
(true in MOZCENTRAL/TESTING, off by default in the GENERIC build).
External services expose a `createSignatureVerifier()` factory that
the Firefox build wires up to `nsIX509CertDB.asyncVerifyPKCS7Object`;
GENERIC builds return null and the toolbar button stays hidden.
UI summary:
- Toolbar button states: loading dots while in flight, then green
check, orange `!`, or red `✕` based on the worst aggregate
signature status.
- Doorhanger contains a banner summarising the document state, then
one card per signature with status row + certificate row (sub-
signatures nested under their outer revision via /ByteRange
containment).
- Icons are mono SVGs themed via `mask-image` + `background-color`
so they pick up light/dark/HCM via `--sig-icon-*` vars; flipped
under RTL via `scaleX(var(--dir-factor))`. The HCM mapping reuses
the alt-text vocabulary (ButtonFace / ButtonText / ButtonBorder /
GrayText / AccentColor / LinkText) so this panel reads the same
as the rest of the editor toolbar in high-contrast mode.
- All visible strings are localized via Fluent
(`pdfjs-digital-signature-properties-*`); status row, banner, and
certificate row use explicit lookup tables instead of generated
ids so a grep finds them.
- Esc + outside-click close the panel through the viewer's existing
handlers; the manager exposes `isOpen`, `close()`, and
`shouldCloseOnClick(target)` for that.
This commit also adds a `test/pdfs/sig_corpus/` directory holding a
Python generator that produces a corpus of signed PDFs covering
every visible state of the doorhanger (verified / untrusted /
expired / invalid / unknown / multi-signature variants). The corpus
is intentionally NOT part of the automated test suite — it is a
manual-test tool. Generated `.pdf` files are gitignored; only the
generator, README, and a `user.js.example` snippet are tracked.
The generator shells out to mozilla-central's
`security/manager/tools/pycms.py` (resolved via `--mozilla-central
<path>` or the `MOZILLA_CENTRAL_SRC` env var) and the embedded test
trust anchors (`pdf-sign-ca` / `pdf-sign-ca-expired`), gated by
`security.pdf_signature_verification.enable_test_trust_anchors` so
the test certificates never validate in shipping Firefox.
In practice we've not accepted PRs with "manual" changes of any non `en-US` locales for many years, however some (older) README/FAQ entries can perhaps be seen as actually inviting such PRs.
Now that l10n updates are running automatically via GitHub Actions, see PR 20749, we're definitely not going to accept any "manual" translation patches so it cannot hurt to de-emphasize localization in various README files.
(Also, since all relevant Fluent files have license headers it doesn't seem meaningful to mention that in the l10n README.)
Update the styles and HTML to reflect the new views manager concept.
For now, nothing about split/merge functionality is implemented or visible.
The new styles for the outline, attachments, and layers will be added later.
The thumbnail view is now accessible with the keyboard.
