- 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>
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