ee7df7ba8c
* Support custom sanitization policy Allowing the gitea administrator to configure sanitization policy allows them to couple external renders and custom templates to support more markup. In particular, the `pandoc` renderer allows generating KaTeX annotations, wrapping them in `<span>` elements with class `math` and either `inline` or `display` (depending on whether or not inline or block mode was requested). This iteration gives the administrator whitelisting powers; carefully crafted regexes will thus let through only the desired attributes necessary to support their custom markup. Resolves: #9054 Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com> * Document new sanitization configuration - Adds basic documentation to app.ini.sample, - Adds an example to the Configuration Cheat Sheet, and - Adds extended information to External Renderers section. Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com> * Drop extraneous length check in newMarkupSanitizer(...) Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com> * Fix plural ELEMENT and ALLOW_ATTR in docs These were left over from their initial names. Make them singular to conform with the current expectations. Signed-off-by: Alexander Scheel <alexander.m.scheel@gmail.com>
78 lines
2.4 KiB
Go
78 lines
2.4 KiB
Go
// Copyright 2017 The Gitea Authors. All rights reserved.
|
|
// Copyright 2017 The Gogs Authors. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package markup
|
|
|
|
import (
|
|
"regexp"
|
|
"sync"
|
|
|
|
"code.gitea.io/gitea/modules/setting"
|
|
|
|
"github.com/microcosm-cc/bluemonday"
|
|
)
|
|
|
|
// Sanitizer is a protection wrapper of *bluemonday.Policy which does not allow
|
|
// any modification to the underlying policies once it's been created.
|
|
type Sanitizer struct {
|
|
policy *bluemonday.Policy
|
|
init sync.Once
|
|
}
|
|
|
|
var sanitizer = &Sanitizer{}
|
|
|
|
// NewSanitizer initializes sanitizer with allowed attributes based on settings.
|
|
// Multiple calls to this function will only create one instance of Sanitizer during
|
|
// entire application lifecycle.
|
|
func NewSanitizer() {
|
|
sanitizer.init.Do(func() {
|
|
ReplaceSanitizer()
|
|
})
|
|
}
|
|
|
|
// ReplaceSanitizer replaces the current sanitizer to account for changes in settings
|
|
func ReplaceSanitizer() {
|
|
sanitizer.policy = bluemonday.UGCPolicy()
|
|
// We only want to allow HighlightJS specific classes for code blocks
|
|
sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^language-\w+$`)).OnElements("code")
|
|
|
|
// Checkboxes
|
|
sanitizer.policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
|
|
sanitizer.policy.AllowAttrs("checked", "disabled").OnElements("input")
|
|
|
|
// Custom URL-Schemes
|
|
sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
|
|
|
|
// Allow keyword markup
|
|
sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^` + keywordClass + `$`)).OnElements("span")
|
|
|
|
// Allow <kbd> tags for keyboard shortcut styling
|
|
sanitizer.policy.AllowElements("kbd")
|
|
|
|
// Custom keyword markup
|
|
for _, rule := range setting.ExternalSanitizerRules {
|
|
if rule.Regexp != nil {
|
|
sanitizer.policy.AllowAttrs(rule.AllowAttr).Matching(rule.Regexp).OnElements(rule.Element)
|
|
} else {
|
|
sanitizer.policy.AllowAttrs(rule.AllowAttr).OnElements(rule.Element)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Sanitize takes a string that contains a HTML fragment or document and applies policy whitelist.
|
|
func Sanitize(s string) string {
|
|
NewSanitizer()
|
|
return sanitizer.policy.Sanitize(s)
|
|
}
|
|
|
|
// SanitizeBytes takes a []byte slice that contains a HTML fragment or document and applies policy whitelist.
|
|
func SanitizeBytes(b []byte) []byte {
|
|
if len(b) == 0 {
|
|
// nothing to sanitize
|
|
return b
|
|
}
|
|
NewSanitizer()
|
|
return sanitizer.policy.SanitizeBytes(b)
|
|
}
|