document.exportPdf {standard: pdfX1a|pdfX3|pdfX4} and the PDF/X presets now
write conforming files instead of being refused:
- every PDF/X file gets a /GTS_PDFX output intent (by default the CMYK
profile in effect, embedded), TrimBox, Trapped, GTS_PDFXVersion (and
GTS_PDFXConformance for X-1a), a title and dates; editing data,
passwords and, in X-1a/X-3, PDF layers are refused
- PDF/X-1a converts every colour and image to a CMYK destination,
untagged, with CMYK spot alternates; X-3 and X-4 tag colours with ICC
profiles
- X-1a and X-3 are written as PDF 1.3 and their transparency is flattened
first (High Resolution preset; images with see-through pixels count,
rasters stay opaque); X-4 keeps transparency, is PDF 1.6 at most and
names the standard in its XMP metadata
- the written file is checked against its standard (soft masks,
transparency groups, opacity, blend modes, RGB in X-1a, fonts not
embedded) and refused rather than mislabelled
- choosing a standard sets the latest compatibility it allows and turns
off what it forbids (engine and Save PDF dialog)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- pdf/src/encrypt.rs encrypts a written PDF with the standard security handler: 128-bit RC4
(PDF 1.4, revision 3; PDF 1.5, revision 4), 128-bit AES (1.6) or 256-bit AES (1.7/2.0,
revision 6), every string and stream, plaintext XMP metadata when asked, the permission bits
(printing none/low/high, five change levels, copy, screen readers). Crypto from RustCrypto
(aes, md-5, sha2: MIT OR Apache-2.0, pure Rust, wasm).
- PDF/A and PDF/X refuse passwords; equal passwords and passwords the algorithm can't take are
refused.
- Opening: the permissions password opens RC4/AES-128 files too; editing data comes back from
an encrypted PDF opened with its password.
- Save PDF › Security: the passwords, permissions and plaintext metadata, the encryption level.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
