Encryption derives its keys from a prepared password, not the typed one:
AES-256 (R6) applies SASLprep, falls back to the password as given if
SASLprep refuses it, and truncates the UTF-8 to 127 bytes; RC4/AES-128
(R2-R4) use PDFDocEncoding cut or padded to exactly 32 bytes, and the
padding starts with "(". Protection::validate checked only the typed
strings, so a permissions password of U+00AD wrote a file that opens with
owner rights and no password, and an open password "A" with a permissions
password U+FF21 (or RC4/AES-128 passwords "a"x31 and "a"x31 + "(") wrote a
file whose open password lifts the restrictions.
pdfcraft-crypt gains effective_password(algorithm, password), the bytes the
keys are derived from (it and create share the private prepared_password
helper), re-exported from pdfcraft-cos. validate refuses a password whose
effective bytes are those of "", and an open and a permissions password
whose effective bytes are equal. Opening files is unchanged.
Fixes#1185.
A PDF protected with only a permissions (owner) password opens without
asking, restricted, and nothing let the user enter that password
afterwards: the security notice only led to a read-only Security tab and
the hint said to reopen the file with the password, which the app had no
way to do (#995, #1077).
Now the security notice and Document Properties > Security offer Unlock...,
and Change settings / Remove security on a restricted document ask for the
permissions password first and then carry on, as Acrobat does. The open
password is refused there.
- crypt: SecurityHandler::authenticate_owner accepts only the owner
password and refuses a different file key.
- cos: Document::unlock upgrades the open document in place; owner and user
passwords unlock the same file key, so nothing is decoded again.
- engine: Session::unlock (not an edit: no undo step, not marked unsaved)
also unlocks the undo and redo states and reopens saves as owner;
Document::can_unlock, EditError::WrongPassword, command protect.unlock.
- ui: the permissions password prompt shares the open prompt's modal; the
notice and Security tab get Unlock...; the disabled-command hints no
longer point at reopening the file.
- i18n: the new strings in all 15 full catalogs (catalog hashes updated).
Tests cover crypt, cos and engine (all four algorithms, wrong and open
passwords, undo, redo, save, removing security afterwards) and the UI
(notice flow, Remove security asking first).
Closes#995Closes#1077
Co-authored-by: Brandon Thomas <[email protected]>
Revisions 2–4 of the standard security handler take the password in
PDFDocEncoding (ISO 32000-2 §7.6.4.3.2, Algorithm 2). PdfCraft authenticates
an encrypted file twice, and neither did that:
- pdfcraft-crypt took Latin-1 and dropped every other character, so "ı"
(0x9A) and "€" (0xA0) vanished and "ılık€" became "lk";
- the renderer (vendored hayro-syntax, "TODO: Convert to PDFDocEncoding")
used the UTF-8 bytes, so any non-ASCII password failed, even "Çok güzel",
which Latin-1 and PDFDocEncoding write alike;
- the engine handed the renderer an owner-recovered user password as Latin-1
characters, which the renderer then read as UTF-8 again.
Files that qpdf or Acrobat protected with such passwords could not be
opened with the right password.
- pdfcraft-crypt encodes R2–R4 passwords in PDFDocEncoding and, for a
password with characters PDFDocEncoding lacks (ğ, ş, İ), also tries its
UTF-8 bytes, which qpdf writes for those. The PDFDocEncoding table moves
here from pdfcraft-cos (which depends on this crate) and cos uses it.
- hayro-syntax (vendored patch 14) tries an R2–R4 password as given, then
in PDFDocEncoding.
- The engine passes a recovered user password to the renderer as UTF-8 when
its bytes are UTF-8 and as PDFDocEncoding otherwise, so the renderer gets
exactly those bytes back.
Co-authored-by: Brandon Thomas <[email protected]>
The app, crates, binaries, bundle id, packaging, icons, screenshots and docs are now
PdfCraft / pdfcraft (repo storytold/pdfcraft). On first launch the desktop app moves the
PrintCraft settings and crash-recovery folders to the new name, and both apps read settings
saved under the old storage key, so upgrades keep recent files, preferences and unsaved work.
The signing test fixtures keep their PrintCraft subject names (they are binary).
Co-authored-by: Claude Opus 5.5 <[email protected]>
AES blocks come from `as_chunks`, the IV from `split_first_chunk`, and the R6 hash takes its
AES key and IV with `first_chunk`, so no `expect` is needed. The crate now denies the panic lints.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Joel Tony