feat: expand secure runtime and workspace UX

src/main/workspace-file-access.ts

@@ -0,0 +1,101 @@
+import type { Dirent } from 'node:fs'
+import { open, opendir, realpath, stat } from 'node:fs/promises'
+import { isAbsolute, relative, resolve } from 'node:path'
+
+export function isPathInside(rootPath: string, candidatePath: string): boolean {
+  const difference = relative(rootPath, candidatePath)
+  return (
+    difference === '' ||
+    (!difference.startsWith('..') && !isAbsolute(difference))
+  )
+}
+
+export async function getCanonicalWorkspace(
+  rootPath: string,
+  invalidDirectoryMessage = '项目工作区不是目录'
+): Promise<string> {
+  const canonicalRoot = await realpath(rootPath)
+  if (!(await stat(canonicalRoot)).isDirectory()) {
+    throw new Error(invalidDirectoryMessage)
+  }
+  return canonicalRoot
+}
+
+export async function resolveExistingWorkspacePath(
+  canonicalRoot: string,
+  pathSegments: string[],
+  expected: 'file' | 'directory'
+): Promise<string> {
+  const candidate = resolve(canonicalRoot, ...pathSegments)
+  if (!isPathInside(canonicalRoot, candidate)) {
+    throw new Error('文件路径不能超出项目工作区')
+  }
+  const canonicalPath = await realpath(candidate)
+  if (!isPathInside(canonicalRoot, canonicalPath)) {
+    throw new Error('文件路径不能通过符号链接超出项目工作区')
+  }
+  const metadata = await stat(canonicalPath)
+  if (
+    (expected === 'file' && !metadata.isFile()) ||
+    (expected === 'directory' && !metadata.isDirectory())
+  ) {
+    throw new Error(
+      expected === 'file' ? '目标不是普通文件' : '目标不是目录'
+    )
+  }
+  return canonicalPath
+}
+
+export async function readBoundedUtf8File(
+  filePath: string,
+  maximumBytes: number,
+  tooLargeMessage: string,
+  invalidUtf8Message: string
+): Promise<{ content: string; size: number }> {
+  const handle = await open(filePath, 'r')
+  try {
+    const metadata = await handle.stat()
+    if (metadata.size > maximumBytes) {
+      throw new Error(tooLargeMessage)
+    }
+    const data = Buffer.alloc(metadata.size + 1)
+    const result = await handle.read(data, 0, data.length, 0)
+    if (result.bytesRead > maximumBytes) {
+      throw new Error(tooLargeMessage)
+    }
+    try {
+      return {
+        content: new TextDecoder('utf-8', { fatal: true }).decode(
+          data.subarray(0, result.bytesRead)
+        ),
+        size: result.bytesRead
+      }
+    } catch (error) {
+      throw new Error(invalidUtf8Message, { cause: error })
+    }
+  } finally {
+    await handle.close()
+  }
+}
+
+export async function listBoundedDirectoryEntries(
+  directoryPath: string,
+  maximumEntries: number,
+  include: (entry: Dirent) => boolean = () => true
+): Promise<{ entries: Dirent[]; truncated: boolean }> {
+  const entries: Dirent[] = []
+  const directory = await opendir(directoryPath)
+  for await (const entry of directory) {
+    if (!include(entry)) {
+      continue
+    }
+    entries.push(entry)
+    if (entries.length > maximumEntries) {
+      break
+    }
+  }
+  return {
+    entries: entries.slice(0, maximumEntries),
+    truncated: entries.length > maximumEntries
+  }
+}