add app and apps icons

src/icons.js

@@ -0,0 +1,174 @@
+'use strict'
+
+const fs = require('fs')
+const path = require('path')
+
+function rvaToOffset(sections, rva) {
+  for (const s of sections) {
+    if (rva >= s.va && rva < s.va + (s.vs || s.rawSize)) return rva - s.va + s.raw
+  }
+  return null
+}
+
+function dirEntries(buf, dirOff) {
+  const named = buf.readUInt16LE(dirOff + 12)
+  const ids = buf.readUInt16LE(dirOff + 14)
+  const out = []
+  for (let i = 0; i < named + ids; i++) {
+    const e = dirOff + 16 + i * 8
+    const nameOrId = buf.readUInt32LE(e)
+    const value = buf.readUInt32LE(e + 4)
+    out.push({ id: nameOrId & 0x7fffffff, isName: (nameOrId & 0x80000000) !== 0, value, isDir: (value & 0x80000000) !== 0 })
+  }
+  return out
+}
+
+function parseIcons(buf) {
+  try {
+    if (buf.length < 64 || buf.readUInt16LE(0) !== 0x5a4d) return null
+    const peOff = buf.readUInt32LE(0x3c)
+    if (peOff + 24 > buf.length || buf.readUInt32LE(peOff) !== 0x00004550) return null
+    const numSections = buf.readUInt16LE(peOff + 6)
+    const optSize = buf.readUInt16LE(peOff + 20)
+    const optOff = peOff + 24
+    const magic = buf.readUInt16LE(optOff)
+    const resRva = magic === 0x20b ? buf.readUInt32LE(optOff + 128) : buf.readUInt32LE(optOff + 112)
+    if (!resRva) return []
+
+    const secOff = optOff + optSize
+    const sections = []
+    for (let i = 0; i < numSections; i++) {
+      const s = secOff + i * 40
+      sections.push({
+        va: buf.readUInt32LE(s + 12),
+        vs: buf.readUInt32LE(s + 8),
+        rawSize: buf.readUInt32LE(s + 16),
+        raw: buf.readUInt32LE(s + 20)
+      })
+    }
+
+    const rootOff = rvaToOffset(sections, resRva)
+    if (rootOff == null) return []
+
+    const typeEntry = dirEntries(buf, rootOff).find(e => e.id === 3 && e.isDir)
+    if (!typeEntry) return []
+    const iconDirOff = rvaToOffset(sections, resRva + (typeEntry.value & 0x7fffffff))
+    if (iconDirOff == null) return []
+
+    const iconDatas = []
+    for (const nameEntry of dirEntries(buf, iconDirOff)) {
+      if (!nameEntry.isDir) continue
+      const langDirOff = rvaToOffset(sections, resRva + (nameEntry.value & 0x7fffffff))
+      if (langDirOff == null) continue
+      const langEntry = dirEntries(buf, langDirOff)[0]
+      if (!langEntry || langEntry.isDir) continue
+      const dataEntryOff = rvaToOffset(sections, resRva + langEntry.value)
+      if (dataEntryOff == null) continue
+      const dataRva = buf.readUInt32LE(dataEntryOff)
+      const dataSize = buf.readUInt32LE(dataEntryOff + 4)
+      const dataOff = rvaToOffset(sections, dataRva)
+      if (dataOff == null || !dataSize) continue
+      iconDatas.push({ id: nameEntry.id, buf: Buffer.from(buf.subarray(dataOff, dataOff + dataSize)) })
+    }
+    if (!iconDatas.length) return []
+
+    const groupEntry = dirEntries(buf, rootOff).find(e => e.id === 14 && e.isDir)
+    if (groupEntry) {
+      const grpDirOff = rvaToOffset(sections, resRva + (groupEntry.value & 0x7fffffff))
+      if (grpDirOff != null) {
+        for (const nameEntry of dirEntries(buf, grpDirOff)) {
+          if (!nameEntry.isDir) continue
+          const langDirOff = rvaToOffset(sections, resRva + (nameEntry.value & 0x7fffffff))
+          if (langDirOff == null) continue
+          const langEntry = dirEntries(buf, langDirOff)[0]
+          if (!langEntry || langEntry.isDir) continue
+          const dataEntryOff = rvaToOffset(sections, resRva + langEntry.value)
+          if (dataEntryOff == null) continue
+          const dataRva = buf.readUInt32LE(dataEntryOff)
+          const dataSize = buf.readUInt32LE(dataEntryOff + 4)
+          const dataOff = rvaToOffset(sections, dataRva)
+          if (dataOff == null || !dataSize) continue
+          const grp = buf.subarray(dataOff, dataOff + dataSize)
+          if (grp.length < 6) continue
+          const count = grp.readUInt16LE(4)
+          const best = { area: -1, buf: null }
+          for (let i = 0; i < count; i++) {
+            const e = 6 + i * 14
+            const w = grp.readUInt8(e) || 256
+            const h = grp.readUInt8(e + 1) || 256
+            const id = grp.readUInt16LE(e + 12)
+            const icon = iconDatas.find(ic => ic.id === id)
+            if (icon && w * h > best.area) {
+              best.area = w * h
+              best.buf = icon.buf
+            }
+          }
+          if (best.buf) return [best.buf]
+        }
+      }
+    }
+    return [iconDatas.reduce((a, b) => (b.buf.length > a.buf.length ? b : a)).buf]
+  } catch {
+    return null
+  }
+}
+
+function pngSize(img) {
+  if (img.length > 24 && img.readUInt32BE(0) === 0x89504e47) {
+    return { w: img.readUInt32BE(16), h: img.readUInt32BE(20) }
+  }
+  return null
+}
+
+function buildIco(images) {
+  const header = Buffer.alloc(6)
+  header.writeUInt16LE(0, 0)
+  header.writeUInt16LE(1, 2)
+  header.writeUInt16LE(images.length, 4)
+  const metas = []
+  const datas = []
+  let offset = 6 + images.length * 16
+  for (const img of images) {
+    let w, h, colors = 0, planes = 1, bpp = 32
+    if (img.readUInt32BE(0) === 0x89504e47) {
+      const dim = pngSize(img) || { w: 256, h: 256 }
+      w = dim.w
+      h = dim.h
+    } else {
+      w = img.readUInt8(0) || 256
+      h = img.readUInt8(1) || 256
+      colors = img.readUInt8(2)
+      planes = img.length > 4 ? img.readUInt16LE(4) || 1 : 1
+      bpp = img.length > 6 ? img.readUInt16LE(6) || 32 : 32
+    }
+    const meta = Buffer.alloc(16)
+    meta.writeUInt8(w >= 256 ? 0 : w, 0)
+    meta.writeUInt8(h >= 256 ? 0 : h, 1)
+    meta.writeUInt8(colors, 2)
+    meta.writeUInt8(0, 3)
+    meta.writeUInt16LE(planes, 4)
+    meta.writeUInt16LE(bpp, 6)
+    meta.writeUInt32LE(img.length, 8)
+    meta.writeUInt32LE(offset, 12)
+    metas.push(meta)
+    datas.push(img)
+    offset += img.length
+  }
+  return Buffer.concat([header, ...metas, ...datas])
+}
+
+function extractIconFromExe(exePath, outPath) {
+  try {
+    const buf = fs.readFileSync(exePath)
+    const icon = parseIcons(buf)
+    if (!icon || !icon.length) return { ok: false, error: 'no-icon' }
+    const ico = buildIco(icon)
+    fs.mkdirSync(path.dirname(outPath), { recursive: true })
+    fs.writeFileSync(outPath, ico)
+    return { ok: true, path: outPath }
+  } catch (err) {
+    return { ok: false, error: String(err && err.message || err) }
+  }
+}
+
+module.exports = { extractIconFromExe, parseIcons, buildIco }