update 优化 富文本内容展示增加xss拦截过滤

src/utils/sanitize.ts

@@ -0,0 +1,197 @@
+const DEFAULT_ALLOWED_TAGS = new Set([
+  'a',
+  'article',
+  'b',
+  'blockquote',
+  'br',
+  'caption',
+  'code',
+  'col',
+  'colgroup',
+  'del',
+  'div',
+  'em',
+  'figcaption',
+  'figure',
+  'h1',
+  'h2',
+  'h3',
+  'h4',
+  'h5',
+  'h6',
+  'hr',
+  'i',
+  'img',
+  'li',
+  'ol',
+  'p',
+  'pre',
+  's',
+  'section',
+  'span',
+  'strong',
+  'sub',
+  'sup',
+  'table',
+  'tbody',
+  'td',
+  'th',
+  'thead',
+  'tr',
+  'u',
+  'ul',
+  'video',
+  'source'
+]);
+
+const URI_ATTRS = new Set(['href', 'src']);
+const GLOBAL_ALLOWED_ATTRS = new Set(['class', 'title', 'alt', 'style']);
+const TAG_ALLOWED_ATTRS: Record<string, Set<string>> = {
+  a: new Set(['href', 'target', 'rel']),
+  img: new Set(['src', 'alt', 'title']),
+  video: new Set(['src', 'poster', 'controls', 'autoplay', 'muted', 'loop']),
+  source: new Set(['src', 'type']),
+  td: new Set(['colspan', 'rowspan']),
+  th: new Set(['colspan', 'rowspan']),
+  col: new Set(['span']),
+  colgroup: new Set(['span'])
+};
+
+const DANGEROUS_TAGS = new Set(['script', 'style', 'iframe', 'object', 'embed', 'link', 'meta', 'base', 'form', 'input', 'button', 'textarea', 'select', 'option', 'svg', 'math']);
+const SAFE_URL_PATTERN = /^(https?:|mailto:|tel:|\/|#|data:image\/(?:png|jpeg|jpg|gif|webp);base64,)/i;
+const ALLOWED_STYLE_PROPS = new Set([
+  'background-color',
+  'color',
+  'font-family',
+  'font-size',
+  'font-style',
+  'font-weight',
+  'height',
+  'line-height',
+  'list-style-type',
+  'margin-left',
+  'max-width',
+  'min-width',
+  'padding-left',
+  'text-align',
+  'text-decoration',
+  'text-indent',
+  'vertical-align',
+  'white-space',
+  'width'
+]);
+const UNSAFE_STYLE_VALUE_PATTERN = /(?:expression\s*\(|url\s*\(|javascript:|vbscript:|data:|@import|behavior:)/i;
+
+const sanitizeUrl = (value: string) => {
+  const normalized = value.trim();
+  if (!normalized) {
+    return '';
+  }
+  return SAFE_URL_PATTERN.test(normalized) ? normalized : '';
+};
+
+const sanitizeStyle = (value: string) => {
+  const declarations = value
+    .split(';')
+    .map((item) => item.trim())
+    .filter(Boolean);
+
+  const safeDeclarations = declarations.flatMap((declaration) => {
+    const separatorIndex = declaration.indexOf(':');
+    if (separatorIndex <= 0) {
+      return [];
+    }
+
+    const property = declaration.slice(0, separatorIndex).trim().toLowerCase();
+    const propertyValue = declaration.slice(separatorIndex + 1).trim();
+
+    if (!ALLOWED_STYLE_PROPS.has(property) || !propertyValue || UNSAFE_STYLE_VALUE_PATTERN.test(propertyValue)) {
+      return [];
+    }
+
+    return [`${property}: ${propertyValue}`];
+  });
+
+  return safeDeclarations.join('; ');
+};
+
+const shouldKeepAttr = (tagName: string, attrName: string) => {
+  if (attrName.startsWith('on')) {
+    return false;
+  }
+  if (GLOBAL_ALLOWED_ATTRS.has(attrName)) {
+    return true;
+  }
+  return TAG_ALLOWED_ATTRS[tagName]?.has(attrName) ?? false;
+};
+
+const sanitizeElement = (element: Element) => {
+  const tagName = element.tagName.toLowerCase();
+
+  if (DANGEROUS_TAGS.has(tagName)) {
+    element.remove();
+    return;
+  }
+
+  if (!DEFAULT_ALLOWED_TAGS.has(tagName)) {
+    const parent = element.parentNode;
+    if (!parent) {
+      element.remove();
+      return;
+    }
+    while (element.firstChild) {
+      parent.insertBefore(element.firstChild, element);
+    }
+    parent.removeChild(element);
+    return;
+  }
+
+  Array.from(element.attributes).forEach((attr) => {
+    const attrName = attr.name.toLowerCase();
+    if (!shouldKeepAttr(tagName, attrName)) {
+      element.removeAttribute(attr.name);
+      return;
+    }
+
+    if (attrName === 'style') {
+      const sanitizedStyle = sanitizeStyle(attr.value);
+      if (!sanitizedStyle) {
+        element.removeAttribute(attr.name);
+        return;
+      }
+      element.setAttribute(attr.name, sanitizedStyle);
+      return;
+    }
+
+    if (URI_ATTRS.has(attrName)) {
+      const sanitized = sanitizeUrl(attr.value);
+      if (!sanitized) {
+        element.removeAttribute(attr.name);
+        return;
+      }
+      element.setAttribute(attr.name, sanitized);
+    }
+  });
+
+  if (tagName === 'a' && element.hasAttribute('target')) {
+    element.setAttribute('rel', 'noopener noreferrer');
+  }
+};
+
+export function sanitizeHtml(html?: string) {
+  if (!html) {
+    return '';
+  }
+
+  const template = document.createElement('template');
+  template.innerHTML = html;
+  const walker = document.createTreeWalker(template.content, NodeFilter.SHOW_ELEMENT);
+  const elements: Element[] = [];
+
+  while (walker.nextNode()) {
+    elements.push(walker.currentNode as Element);
+  }
+
+  elements.forEach(sanitizeElement);
+  return template.innerHTML;
+}