2 commits

Author	SHA1	Message	Date
Daniel	bd8e413bc7	fix: an assistant attachment must be the image type it claims to be ... The MIME type was taken on trust here. Anything at all could be posted as image/png: it passed the size and base64 checks, was stored in the saved chat, and was handed to a provider as a data URI. Documents and S3 uploads have always been sniffed by fileType.js; this was the one upload path that was not. Now sniffed with the same helper, so there is one idea of what a PNG looks like. A PHP payload, a shell script, an ELF or PE binary, a zip, or a real PDF labelled image/png are all refused with a message that says what is wrong. What this does not claim: bytes hidden after a valid PNG header still make a valid PNG, and no sniffer can promise otherwise. The protection is that the file is never executed and never served as anything but an image. Existing fixtures used buffers of 0x07 as stand-in images, which are correctly refused now. They carry real file headers instead — a fixture should be the thing it claims to be, exactly like a real upload. Also adds the deck theme system: five palettes in assets/deck-themes.json, render_pptx.py rebinding its palette from the theme rather than hardcoding it, the theme carried on the deck and validated against the same catalogue the renderer reads, a picker on the generate form, and PUT /my-resources/:id/theme to re-skin a stored deck with no model call. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Dv6sqaY6Vq3ChZHMem3cnU	2026-09-12 19:00:10 +02:00
Daniel	15a8b399ba	feat: slides are built by pandoc from markdown, with a reference template ... pptxgenjs is gone, and with it 269 lines of hand-rolled markdown parsing. It stretched every image. Reading the slide XML it emitted shows why: it writes the target box verbatim with <a:stretch/> and a no-op srcRect, so a 200x800 image handed an 11.8x3.9 box came out 1:4 squashed to 3:1. It could not do better — it never measures an image, and its own getSizeFromImage is commented out and marked "currently unused", reaching for a package called sizeof that does not exist. pandoc measures them: a 300x175 source renders at aspect 1.714 and a 160x360 at 0.445, verified by rendering the deck to PDF and looking at it. Tables, ordered and unordered lists, bold, italic and subscripts all come out natively, and the fonts, palette and slide layouts come from assets/learning/slides-reference.pptx. Design now lives in that file: restyling the decks means editing it in PowerPoint, not editing this route. Only images the requester owns can reach a deck. pandoc resolves an image link against the filesystem, so a markdown link naming any local path would read that file into the presentation. Images are fetched by id through the ownership check, written into a per-request temporary directory under names we choose, and every image link that did not resolve is removed rather than passed through. The directory is removed in a finally block, and the conversion has a 60s timeout so it cannot hang a request. pandoc is in the image rather than a sidecar, because an export must not fail for reasons outside this container. It costs 197MB (307 -> 504). Removing pptxgenjs also removed image-size, and with it both high-severity advisories — GHSA-w3rx-r6r6-pgpr and GHSA-5p2g-fcmc-qvqq, ICNS/JXL/HEIF parser denial of service, ranged <=2.0.2 with no fixed release to upgrade to. npm audit goes from 2 high and 2 moderate to 2 moderate. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Dv6sqaY6Vq3ChZHMem3cnU	2026-09-11 13:25:24 +02:00