feat: align with upstream 1.5.9.9

app/utils/markdown.js

@@ -0,0 +1,83 @@
+import { Marked } from 'marked'
+import xssPkg from 'xss'
+const { escapeAttrValue, filterXSS, friendlyAttrValue, safeAttrValue, whiteList } = xssPkg
+
+const ALLOWED_LINK_SCHEMES = new Set(['http', 'https', 'mailto', 'tel'])
+const ALLOWED_IMAGE_SCHEMES = new Set(['http', 'https'])
+const SAFE_RASTER_DATA_URL = /^data:image\/(?:avif|gif|jpe?g|png|webp);base64,[a-z0-9+/=\s]+$/i
+
+const escapeHtml = (text) => text.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
+
+const getUrlScheme = (value) => {
+  const colonIndex = value.indexOf(':')
+  if (colonIndex < 0) return null
+
+  const pathBoundaryIndexes = ['/', '?', '#']
+    .map((character) => value.indexOf(character))
+    .filter((index) => index >= 0)
+  const firstPathBoundary = pathBoundaryIndexes.length
+    ? Math.min(...pathBoundaryIndexes)
+    : Number.POSITIVE_INFINITY
+
+  if (firstPathBoundary < colonIndex) return null
+
+  const scheme = value.slice(0, colonIndex).replace(/\s/g, '')
+  return /^[a-z][a-z0-9+.-]*$/i.test(scheme) ? scheme.toLowerCase() : 'invalid'
+}
+
+const isSafeUrl = (tag, name, value) => {
+  const scheme = getUrlScheme(value)
+  if (!scheme) return true
+
+  if (name === 'href') return ALLOWED_LINK_SCHEMES.has(scheme)
+  if (name === 'src') {
+    if (tag === 'img' && scheme === 'data') return SAFE_RASTER_DATA_URL.test(value)
+    return ALLOWED_IMAGE_SCHEMES.has(scheme)
+  }
+
+  return false
+}
+
+const sanitizeAttributeValue = (tag, name, value, cssFilter) => {
+  if (name !== 'href' && name !== 'src') {
+    return safeAttrValue(tag, name, value, cssFilter)
+  }
+
+  const normalizedValue = friendlyAttrValue(value).trim()
+  return isSafeUrl(tag, name, normalizedValue) ? escapeAttrValue(normalizedValue) : ''
+}
+
+// 创建独立的 marked 实例，避免全局污染和 HMR 重复注册
+const markedInstance = new Marked({
+  gfm: true,
+  breaks: true,
+  renderer: {
+    html(token) {
+      const rawHtml = typeof token === 'string' ? token : token.text
+      return escapeHtml(rawHtml || '')
+    }
+  }
+})
+
+// xss 白名单：默认白名单 + GFM 任务列表 checkbox + code 类名（为语法高亮预留）
+const xssOptions = {
+  whiteList: {
+    ...whiteList,
+    input: ['type', 'checked', 'disabled'],
+    code: ['class']
+  },
+  safeAttrValue: sanitizeAttributeValue
+}
+
+/**
+ * 将 Markdown 文本渲染为安全 HTML
+ * 两层防护：marked 禁用原始 HTML + xss 清洗（禁 script、on* 事件、javascript: 协议）
+ *
+ * @param {string} text Markdown 文本
+ * @returns {string} 安全的 HTML 字符串
+ */
+export function renderMarkdown(text) {
+  if (!text || typeof text !== 'string') return ''
+  const rawHtml = markedInstance.parse(text)
+  return filterXSS(rawHtml, xssOptions)
+}