1
0
Fork 0
mirror of https://codeberg.org/forgejo/forgejo.git synced 2024-11-24 08:57:03 -05:00
forgejo/modules/markup/sanitizer.go
Mai-Lapyst 22aedc6c96
[v7.0/forgejo] Render inline file permalinks
Backport: https://codeberg.org/forgejo/forgejo/pulls/2669

(cherry picked from commit 1d3240887c)
(cherry picked from commit 781a37fbe1)
(cherry picked from commit 8309f008c2)
(cherry picked from commit fae8d9f70d)
(cherry picked from commit 6721cba75b)
(cherry picked from commit 562e5cdf32)
(cherry picked from commit d789d33229)
(cherry picked from commit 8218e80bfc)
(cherry picked from commit 10bca456a9)
(cherry picked from commit db6f6281fc)
(cherry picked from commit ed8e8a792e)
(cherry picked from commit d6428f92ce)
(cherry picked from commit 069d87b80f)
(cherry picked from commit 2b6546adc9)
(cherry picked from commit 4c7cb0a5d2)
(cherry picked from commit 7e0014dd13)
(cherry picked from commit 16a8658878)
(cherry picked from commit 6e98bacbbd)
2024-04-01 16:15:58 +02:00

233 lines
9.1 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// Copyright 2017 The Gogs Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"io"
"net/url"
"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 {
defaultPolicy *bluemonday.Policy
descriptionPolicy *bluemonday.Policy
rendererPolicies map[string]*bluemonday.Policy
init sync.Once
}
var (
sanitizer = &Sanitizer{}
allowAllRegex = regexp.MustCompile(".+")
)
// 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() {
InitializeSanitizer()
})
}
// InitializeSanitizer (re)initializes the current sanitizer to account for changes in settings
func InitializeSanitizer() {
sanitizer.rendererPolicies = map[string]*bluemonday.Policy{}
sanitizer.defaultPolicy = createDefaultPolicy()
sanitizer.descriptionPolicy = createRepoDescriptionPolicy()
for name, renderer := range renderers {
sanitizerRules := renderer.SanitizerRules()
if len(sanitizerRules) > 0 {
policy := createDefaultPolicy()
addSanitizerRules(policy, sanitizerRules)
sanitizer.rendererPolicies[name] = policy
}
}
}
func createDefaultPolicy() *bluemonday.Policy {
policy := bluemonday.UGCPolicy()
// For JS code copy and Mermaid loading state
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^code-block( is-loading)?$`)).OnElements("pre")
// For color preview
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^color-preview$`)).OnElements("span")
// For attention
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^attention-header attention-\w+$`)).OnElements("blockquote")
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^attention-\w+$`)).OnElements("strong")
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^attention-icon attention-\w+ svg octicon-[\w-]+$`)).OnElements("svg")
policy.AllowAttrs("viewBox", "width", "height", "aria-hidden").OnElements("svg")
policy.AllowAttrs("fill-rule", "d").OnElements("path")
// For Chroma markdown plugin
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^(chroma )?language-[\w-]+( display)?( is-loading)?$`)).OnElements("code")
// Checkboxes
policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
policy.AllowAttrs("checked", "disabled", "data-source-position").OnElements("input")
// Custom URL-Schemes
if len(setting.Markdown.CustomURLSchemes) > 0 {
policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
} else {
policy.AllowURLSchemesMatching(allowAllRegex)
// Even if every scheme is allowed, these three are blocked for security reasons
disallowScheme := func(*url.URL) bool {
return false
}
policy.AllowURLSchemeWithCustomPolicy("javascript", disallowScheme)
policy.AllowURLSchemeWithCustomPolicy("vbscript", disallowScheme)
policy.AllowURLSchemeWithCustomPolicy("data", disallowScheme)
}
// Allow classes for anchors
policy.AllowAttrs("class").Matching(regexp.MustCompile(`ref-issue( ref-external-issue)?`)).OnElements("a")
// Allow classes for task lists
policy.AllowAttrs("class").Matching(regexp.MustCompile(`task-list-item`)).OnElements("li")
// Allow classes for org mode list item status.
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^(unchecked|checked|indeterminate)$`)).OnElements("li")
// Allow icons
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^icon(\s+[\p{L}\p{N}_-]+)+$`)).OnElements("i")
// Allow classes for emojis
policy.AllowAttrs("class").Matching(regexp.MustCompile(`emoji`)).OnElements("img")
// Allow icons, emojis, chroma syntax and keyword markup on span
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^((icon(\s+[\p{L}\p{N}_-]+)+)|(emoji)|(language-math display)|(language-math inline))$|^([a-z][a-z0-9]{0,2})$|^` + keywordClass + `$`)).OnElements("span")
// Allow 'color' and 'background-color' properties for the style attribute on text elements.
policy.AllowStyles("color", "background-color").OnElements("span", "p")
// Allow classes for file preview links...
policy.AllowAttrs("class").Matching(regexp.MustCompile("^(lines-num|lines-code chroma)$")).OnElements("td")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^code-inner$")).OnElements("code")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^file-preview-box$")).OnElements("div")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^ui table$")).OnElements("div")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^header$")).OnElements("div")
policy.AllowAttrs("data-line-number").Matching(regexp.MustCompile("^[0-9]+$")).OnElements("span")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^text small grey$")).OnElements("span")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^file-preview*")).OnElements("table")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^lines-escape$")).OnElements("td")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^toggle-escape-button btn interact-bg$")).OnElements("button")
policy.AllowAttrs("title").OnElements("button")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^ambiguous-code-point$")).OnElements("span")
policy.AllowAttrs("data-tooltip-content").OnElements("span")
policy.AllowAttrs("class").Matching(regexp.MustCompile("muted|(text black)")).OnElements("a")
policy.AllowAttrs("class").Matching(regexp.MustCompile("^ui warning message tw-text-left$")).OnElements("div")
// Allow generally safe attributes
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",
}
generalSafeElements := []string{
"h1", "h2", "h3", "h4", "h5", "h6", "h7", "h8", "br", "b", "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",
}
policy.AllowAttrs(generalSafeAttrs...).OnElements(generalSafeElements...)
policy.AllowAttrs("src", "autoplay", "controls").OnElements("video")
policy.AllowAttrs("itemscope", "itemtype").OnElements("div")
// FIXME: Need to handle longdesc in img but there is no easy way to do it
// Custom keyword markup
addSanitizerRules(policy, setting.ExternalSanitizerRules)
return policy
}
// createRepoDescriptionPolicy returns a minimal more strict policy that is used for
// repository descriptions.
func createRepoDescriptionPolicy() *bluemonday.Policy {
policy := bluemonday.NewPolicy()
// Allow italics and bold.
policy.AllowElements("i", "b", "em", "strong")
// Allow code.
policy.AllowElements("code")
// Allow links
policy.AllowAttrs("href", "target", "rel").OnElements("a")
// Allow classes for emojis
policy.AllowAttrs("class").Matching(regexp.MustCompile(`^emoji$`)).OnElements("img", "span")
policy.AllowAttrs("aria-label").OnElements("span")
return policy
}
func addSanitizerRules(policy *bluemonday.Policy, rules []setting.MarkupSanitizerRule) {
for _, rule := range rules {
if rule.AllowDataURIImages {
policy.AllowDataURIImages()
}
if rule.Element != "" {
if rule.Regexp != nil {
policy.AllowAttrs(rule.AllowAttr).Matching(rule.Regexp).OnElements(rule.Element)
} else {
policy.AllowAttrs(rule.AllowAttr).OnElements(rule.Element)
}
}
}
}
// SanitizeDescription sanitizes the HTML generated for a repository description.
func SanitizeDescription(s string) string {
NewSanitizer()
return sanitizer.descriptionPolicy.Sanitize(s)
}
// Sanitize takes a string that contains a HTML fragment or document and applies policy whitelist.
func Sanitize(s string) string {
NewSanitizer()
return sanitizer.defaultPolicy.Sanitize(s)
}
// SanitizeReader sanitizes a Reader
func SanitizeReader(r io.Reader, renderer string, w io.Writer) error {
NewSanitizer()
policy, exist := sanitizer.rendererPolicies[renderer]
if !exist {
policy = sanitizer.defaultPolicy
}
return policy.SanitizeReaderToWriter(r, w)
}