게시물 Export ZIP Import 추가 v1.5.27

server/utils/zip-reader.js

@@ -0,0 +1,123 @@
+import { inflateRawSync } from 'node:zlib'
+
+/**
+ * ZIP 엔트리 경로를 안전하게 정리한다.
+ * @param {string} value - ZIP 내부 경로
+ * @returns {string} 정리된 경로
+ */
+const normalizeZipEntryPath = (value) => String(value || '')
+  .replace(/\\/g, '/')
+  .replace(/^\/+/g, '')
+  .split('/')
+  .filter((part) => part && part !== '.' && part !== '..')
+  .join('/')
+
+/**
+ * ZIP 종료 레코드 위치를 찾는다.
+ * @param {Buffer} buffer - ZIP 파일 버퍼
+ * @returns {number} 종료 레코드 위치
+ */
+const findEndOfCentralDirectoryOffset = (buffer) => {
+  const signature = 0x06054b50
+  const minOffset = Math.max(0, buffer.length - 65557)
+
+  for (let offset = buffer.length - 22; offset >= minOffset; offset -= 1) {
+    if (buffer.readUInt32LE(offset) === signature) {
+      return offset
+    }
+  }
+
+  return -1
+}
+
+/**
+ * ZIP 엔트리 데이터를 압축 해제한다.
+ * @param {Buffer} buffer - 전체 ZIP 버퍼
+ * @param {Object} entry - 중앙 디렉터리 엔트리
+ * @returns {Buffer} 압축 해제된 데이터
+ */
+const readZipEntryData = (buffer, entry) => {
+  const localHeaderOffset = entry.localHeaderOffset
+
+  if (buffer.readUInt32LE(localHeaderOffset) !== 0x04034b50) {
+    throw new Error('INVALID_ZIP_LOCAL_HEADER')
+  }
+
+  const localNameLength = buffer.readUInt16LE(localHeaderOffset + 26)
+  const localExtraLength = buffer.readUInt16LE(localHeaderOffset + 28)
+  const dataOffset = localHeaderOffset + 30 + localNameLength + localExtraLength
+  const compressedData = buffer.subarray(dataOffset, dataOffset + entry.compressedSize)
+
+  if (entry.compressionMethod === 0) {
+    return Buffer.from(compressedData)
+  }
+
+  if (entry.compressionMethod === 8) {
+    return inflateRawSync(compressedData)
+  }
+
+  throw new Error('UNSUPPORTED_ZIP_COMPRESSION')
+}
+
+/**
+ * ZIP 파일 버퍼를 파일 엔트리 목록으로 읽는다.
+ * @param {Buffer} buffer - ZIP 파일 버퍼
+ * @returns {Array<{ path: string, data: Buffer }>} 파일 엔트리 목록
+ */
+export const readZipBufferEntries = (buffer) => {
+  if (!Buffer.isBuffer(buffer) || buffer.length < 22) {
+    throw new Error('INVALID_ZIP_FILE')
+  }
+
+  const endOffset = findEndOfCentralDirectoryOffset(buffer)
+
+  if (endOffset < 0) {
+    throw new Error('INVALID_ZIP_FILE')
+  }
+
+  const entryCount = buffer.readUInt16LE(endOffset + 10)
+  const centralDirectorySize = buffer.readUInt32LE(endOffset + 12)
+  const centralDirectoryOffset = buffer.readUInt32LE(endOffset + 16)
+  const centralDirectoryEnd = centralDirectoryOffset + centralDirectorySize
+
+  if (centralDirectoryOffset < 0 || centralDirectoryEnd > buffer.length) {
+    throw new Error('INVALID_ZIP_FILE')
+  }
+
+  const entries = []
+  let offset = centralDirectoryOffset
+
+  for (let index = 0; index < entryCount; index += 1) {
+    if (buffer.readUInt32LE(offset) !== 0x02014b50) {
+      throw new Error('INVALID_ZIP_CENTRAL_DIRECTORY')
+    }
+
+    const compressionMethod = buffer.readUInt16LE(offset + 10)
+    const compressedSize = buffer.readUInt32LE(offset + 20)
+    const uncompressedSize = buffer.readUInt32LE(offset + 24)
+    const nameLength = buffer.readUInt16LE(offset + 28)
+    const extraLength = buffer.readUInt16LE(offset + 30)
+    const commentLength = buffer.readUInt16LE(offset + 32)
+    const localHeaderOffset = buffer.readUInt32LE(offset + 42)
+    const rawPath = buffer.subarray(offset + 46, offset + 46 + nameLength).toString('utf8')
+    const normalizedPath = normalizeZipEntryPath(rawPath)
+    const isDirectory = rawPath.replace(/\\/g, '/').endsWith('/')
+
+    if (normalizedPath && !isDirectory && !normalizedPath.startsWith('__MACOSX/')) {
+      entries.push({
+        path: normalizedPath,
+        compressionMethod,
+        compressedSize,
+        uncompressedSize,
+        localHeaderOffset
+      })
+    }
+
+    offset += 46 + nameLength + extraLength + commentLength
+  }
+
+  return entries.map((entry) => ({
+    path: entry.path,
+    data: readZipEntryData(buffer, entry)
+  }))
+}