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gitea/modules/markup/sanitizer_default.go
Nicolas 26d83c932a
Instance-wide (global) info banner and maintenance mode (#36571)
The banner allows site operators to communicate important announcements
(e.g., maintenance windows, policy updates, service notices) directly
within the UI.

The maintenance mode only allows admin to access the web UI.

* Fix #2345
* Fix #9618

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
2026-02-26 23:16:11 +08:00

112 lines
4.3 KiB
Go

// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"html/template"
"io"
"net/url"
"regexp"
"code.gitea.io/gitea/modules/setting"
"github.com/microcosm-cc/bluemonday"
)
func (st *Sanitizer) createDefaultPolicy() *bluemonday.Policy {
policy := bluemonday.UGCPolicy()
// NOTICE: DO NOT add special "class" regexp rules here anymore, use RenderInternal.SafeAttr instead
// General safe SVG attributes
policy.AllowAttrs("viewBox", "width", "height", "aria-hidden", "data-attr-class").OnElements("svg")
policy.AllowAttrs("fill-rule", "d").OnElements("path")
// Checkboxes
policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
policy.AllowAttrs("checked", "disabled", "data-source-position").OnElements("input")
// Chroma always uses 1-2 letters for style names, we could tolerate it at the moment
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^\w{0,2}$`)).OnElements("span")
// Line numbers on codepreview
policy.AllowAttrs("data-line-number").OnElements("span")
// Custom URL-Schemes
if len(setting.Markdown.CustomURLSchemes) > 0 {
policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
} else {
policy.AllowURLSchemesMatching(st.allowAllRegex)
// Even if every scheme is allowed, these three are blocked for security reasons
disallowScheme := func(*url.URL) bool {
return false
}
policy.AllowURLSchemeWithCustomPolicy("javascript", disallowScheme)
policy.AllowURLSchemeWithCustomPolicy("vbscript", disallowScheme)
policy.AllowURLSchemeWithCustomPolicy("data", disallowScheme)
}
// Allow classes for org mode list item status.
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^(unchecked|checked|indeterminate)$`)).OnElements("li")
// Allow 'color' and 'background-color' properties for the style attribute on text elements.
policy.AllowStyles("color", "background-color").OnElements("div", "span", "p", "tr", "th", "td")
policy.AllowAttrs("src", "autoplay", "controls").OnElements("video")
policy.AllowAttrs("loading").OnElements("img")
// Allow generally safe attributes (reference: https://github.com/jch/html-pipeline)
generalSafeAttrs := []string{
"abbr", "accept", "accept-charset",
"accesskey", "action", "align", "alt",
"aria-describedby", "aria-hidden", "aria-label", "aria-labelledby",
"axis", "border", "cellpadding", "cellspacing", "char",
"charoff", "charset", "checked",
"clear", "cols", "colspan", "color",
"compact", "coords", "datetime", "dir",
"disabled", "enctype", "for", "frame",
"headers", "height", "hreflang",
"hspace", "ismap", "label", "lang",
"maxlength", "media", "method",
"multiple", "name", "nohref", "noshade",
"nowrap", "open", "prompt", "readonly", "rel", "rev",
"rows", "rowspan", "rules", "scope",
"selected", "shape", "size", "span",
"start", "summary", "tabindex", "target",
"title", "type", "usemap", "valign", "value",
"vspace", "width", "itemprop", "itemscope", "itemtype",
"data-markdown-generated-content", "data-attr-class",
}
generalSafeElements := []string{
"h1", "h2", "h3", "h4", "h5", "h6", "h7", "h8", "br", "b", "center", "i", "strong", "em", "a", "pre", "code", "img", "tt",
"div", "ins", "del", "sup", "sub", "p", "ol", "ul", "table", "thead", "tbody", "tfoot", "blockquote", "label",
"dl", "dt", "dd", "kbd", "q", "samp", "var", "hr", "ruby", "rt", "rp", "li", "tr", "td", "th", "s", "strike", "summary",
"details", "caption", "figure", "figcaption",
"abbr", "bdo", "cite", "dfn", "mark", "small", "span", "time", "video", "wbr",
}
// FIXME: Need to handle longdesc in img but there is no easy way to do it
policy.AllowAttrs(generalSafeAttrs...).OnElements(generalSafeElements...)
// Custom keyword markup
defaultSanitizer.addSanitizerRules(policy, setting.ExternalSanitizerRules)
return policy
}
// Sanitize use default sanitizer policy to sanitize a string
func Sanitize(s string) template.HTML {
return template.HTML(GetDefaultSanitizer().defaultPolicy.Sanitize(s))
}
// SanitizeReader sanitizes a Reader
func SanitizeReader(r io.Reader, renderer string, w io.Writer) error {
policy, exist := GetDefaultSanitizer().rendererPolicies[renderer]
if !exist {
policy = GetDefaultSanitizer().defaultPolicy
}
return policy.SanitizeReaderToWriter(r, w)
}