2b:null 2c:["$","title",null,{"children":"[Archive][Tool] Extracting Compound File Binary Format Content to ZIP | UnluckyNinja | Observable"}] 31:T54f,DiFAT Sectors: - Contain indexes that point to a FAT Sector. - Starting point is specified in header, end of chain if size < 109. - Its next sector is specified by its last uint32. FAT Sectors: - Contain the next sector index that follows current index in the table, except for DiFAT Sectors (its follow-up is specified in itself as the last uint32 in the sector), and FAT Sectors itself (it's specified in DiFAT). - Starting point is specified in DiFAT array. - Its next sector is specified in DiFAT array. Mini FAT: - A sector-in-sector FAT. Contain mini stream's next sector info, which is also in mini fat. - Starting point is specified in header. - Its own next sector is specified in FAT Sectors. Mini Stream: - Contain the actual content of stream entry in directory sectors. - Starting point and total length is specified in the root entry of directory sector. - Its next sector is specified in Mini FAT. Directory Sectors: - Contain information of stored directory structure, in an array of red-black tree. - Starting point is specified in header. - Its next sector is specified in FAT Sectors. - Root entry specifies starting FAT index of mini stream, and its total length. - For other stream entries, each either specifies starting point of its content in FAT (when size >= 4096B), or in mini FAT (when size < 4096B). 32:T6fb,zip = { if (!parsed?.cfb) return null const MAX_ZIP_SIZE_IN_BYTES = 500 * 1024 * 1024 const MAX_POSSIBLE_SIZE_PER_FILE = 50 * 1024 * 1024 const promise = new Promise((resolve, reject) => { const buffer = new ArrayBuffer(1024, { maxByteLength: MAX_ZIP_SIZE_IN_BYTES }); const blob = new Uint8Array(buffer); let totalSize = 0; const zip = new fflate.Zip((err, dat, final) => { if (err) { reject(err); } const offset = totalSize; totalSize += dat.byteLength; // make buffer resizable if (buffer.byteLength < totalSize) { buffer.resize(totalSize); } blob.set(dat, offset); if (final) { console.log('final: ' + final) resolve(blob) } }); const cfb = parsed.cfb; // root object function walk(entry, parent) { if (entry.objectType === 2) { // stream object const u8arr = cfbReader.readStreamObjectContent( cfb, Number(entry.startingSectorLocation), Number(entry.streamSize) ); const exts = sigs.find((it) => it.filter(u8arr))?.ext; let suffix = ""; if (exts && !exts.some((it) => entry.name.endsWith(it))) { suffix = "." + exts[0]; } const file = new fflate.AsyncZipDeflate(`${parent}/${entry.name}${suffix}`); zip.add(file); file.push(u8arr, true); } if (entry.leftSibling) { walk(entry.leftSibling, parent); } if (entry.rightSibling) { walk(entry.rightSibling, parent); } if (entry.child) { walk(entry.child, `${parent}/${entry.name}`); } } walk(parsed.entries[0].child, "root_" + Date.now()); zip.end(); }); return await promise }33:T51c,sigs = { return [{ filter: (typedArray)=>{ const sig = [0xFF, 0xD8, 0xFF] if (typedArray.length < sig.length) return false return sig.every((v,i)=>{ return typedArray[i] === v }) }, ext: ['jpg', 'jpeg'], },{ filter: (typedArray)=>{ const sig = [0x47, 0x49, 0x46, 0x38] if (typedArray.length < sig.length) return false return sig.every((v,i)=>{ return typedArray[i] === v }) }, ext: ['gif'], },{ filter: (typedArray)=>{ const sig = [0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A] if (typedArray.length < sig.length) return false return sig.every((v,i)=>{ return typedArray[i] === v }) }, ext: ['png'], },{ filter: (typedArray)=>{ const sig0 = [0x52, 0x49, 0x46, 0x46] const sig8 = [0x57, 0x45, 0x42, 0x50] if (typedArray.length < 12) return false return sig0.every((v,i)=>{ return typedArray[i] === v }) && sig8.every((v,i)=>{ return typedArray[i+8] === v }) }, ext: ['webp'], },{ filter: (typedArray)=>{ const sig = [0x42, 0x4D] if (typedArray.length < sig.length) return false return sig.every((v,i)=>{ return typedArray[i] === v }) }, ext: ['bmp'], }] }34:[] 2f:{"id":"6566626f9376fb6a","slug":null,"title":"[Archive][Tool] 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Extracting Compound File Binary Format Content to ZIP","cells":[{"id":0,"value":"# [Archive][Tool] Extracting Compound File Binary Format Content to ZIP\n**Codes here are reserved only for backlog, go to https://github.com/UnluckyNinja/qqemote-extractor to see updated source code (synced calls to fflate in separate worker drastically reduced memory usage).**","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":100,"value":"CFB Format details:\n\nhttps://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-cfb/05060311-bfce-4b12-874d-71fd4ce63aea","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":345,"value":"$31","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":88,"value":"newDropArea(files, dnd.multiDropHandler(arr=>mutable files = arr), dnd.dragover)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":92,"value":"mutable files = []","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":530,"value":"{\n yield htl.html`Processing, please wait...`\n if (!zip) {\n yield htl.html`Drop file above`\n } else {\n const url = URL.createObjectURL(\n new Blob([zip.buffer.transferToFixedLength()], { type: \"application/zip-compressed\" })\n );\n invalidation.then(() => {\n URL.revokeObjectURL(url);\n });\n yield htl.html`\nClick to download\n`;\n }\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":158,"value":"$32","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":481,"value":"{\n if (!parsed?.blob) return\n const blob = new Blob([parsed.blob.buffer])\n const url = URL.createObjectURL(blob)\n invalidation.then(()=>{\n URL.revokeObjectURL(url)\n })\n return htl.html`

`\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":55,"value":"parsed = {\n if (files.length === 0) return null\n const buf = await files[0].file.arrayBuffer()\n const cfb = new cfbReader.CompoundFileBinary(buf)\n\n const entries = []\n let sec = 0\n let dirOffset\n let stop = false\n while (!stop) {\n try {\n dirOffset = cfb.getDirectorySectorOffsetAt(sec)\n } catch (err) {\n stop = true\n break\n }\n entries.push(...cfbReader.readDirectorySectorInfoV3(cfb, sec).entries)\n ++sec\n }\n for (const it of entries) {\n it.child = entries[it.childID]\n it.leftSibling = entries[it.leftSiblingID]\n it.rightSibling = entries[it.rightSiblingID]\n }\n const file = cfbReader.readDirectoryEntryInfo(cfb, 10)\n const blob = cfbReader.readStreamObjectContent(cfb, Number(file.startingSectorLocation), Number(file.streamSize))\n // const file6 = cfbReader.readStreamObjectContent(cfb, 128, 2384)\n \n return {\n cfb,\n entries,\n file,\n blob,\n // file6\n }\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":453,"value":"cfbReader = importPkg('https://pkg.pr.new/UnluckyNinja/cfb-reader@e63ab3b', 'dist/cfb-reader.browser.mjs')","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":514,"value":"$33","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":502,"value":"fflate = require('fflate@0.8.2/umd/index.js')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"b = require('binspector@0.5.3/dist/binspector.js')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":25,"value":"esbuild = {\n const module = await import('https://cdn.skypack.dev/esbuild-wasm@0.24.2?min')\n await module.initialize({\n wasmURL: 'https://cdn.jsdelivr.net/npm/esbuild-wasm@0.24.2/esbuild.wasm',\n })\n return module\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":451,"value":"import { generateForm, importPkg } from '@unluckyninja/pkg-pr-new'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":90,"value":"import {newDropArea, dnd} from \"@unluckyninja/fileapi\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W34","stdlib":"1","titling":"auto"}} 30:"$2f:body"