allow html in comment, sanitize with bluemonday

This commit is contained in:
Umputun
2017-12-24 14:41:35 -06:00
parent a653c0af42
commit cca529b0b3
29 changed files with 10712 additions and 16 deletions
+3 -3
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@@ -22,12 +22,12 @@ func TestDisqus_Convert(t *testing.T) {
assert.Equal(t, 3, len(res), "3 comments total, 1 spam excluded")
exp0 := store.Comment{
ID: "3565798471341011339",
ID: "299619020",
Locator: store.Locator{
SiteID: "test",
URL: "https://radio-t.com/p/2011/03/05/podcast-229/",
},
Text: "<p>The quick brown fox jumps over the lazy dog.</p>",
Text: `<p>The quick brown fox jumps over the lazy dog.</p><p><a href="https://https://radio-t.com" rel="nofollow noopener" title="radio-t">some link</a></p>`,
User: store.User{
Name: "Alexander Blah",
ID: "facebook-1787732238",
@@ -87,7 +87,7 @@ var xmlTest = `<?xml version="1.0" encoding="utf-8"?>
<post dsq:id="299619020">
<id>3565798471341011339</id>
<message>
<![CDATA[<p>The quick brown fox jumps over the lazy dog.</p>]]>
<![CDATA[<p>The quick brown fox jumps over the lazy dog.</p><p><a href="https://https://radio-t.com" rel="nofollow noopener" title="radio-t">some link</a></p>]]>
</message>
<createdAt>2011-08-31T15:16:29Z</createdAt>
<isDeleted>false</isDeleted>
+23 -11
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@@ -2,7 +2,6 @@ package rest
import (
"errors"
"html/template"
"log"
"net/http"
"path/filepath"
@@ -15,6 +14,9 @@ import (
"github.com/go-chi/render"
"github.com/gorilla/sessions"
"bytes"
"encoding/json"
"github.com/umputun/remark/app/rest/auth"
"github.com/umputun/remark/app/store"
)
@@ -107,14 +109,8 @@ func (s *Server) createCommentCtrl(w http.ResponseWriter, r *http.Request) {
comment.ID = "" // don't allow user to define ID, force auto-gen
comment.Timestamp = time.Time{} // reset time, force auto-gen
comment.Text = template.HTMLEscapeString(comment.Text)
comment.User = user
comment.User.IP = strings.Split(r.RemoteAddr, ":")[0]
comment.User.ID = template.HTMLEscapeString(user.ID)
comment.User.Name = template.HTMLEscapeString(user.Name)
comment.User.Picture = template.HTMLEscapeString(user.Picture)
comment.User.Profile = template.HTMLEscapeString(user.Profile)
comment.User.Admin = user.Admin
log.Printf("[INFO] create comment %+v", comment)
@@ -166,7 +162,7 @@ func (s *Server) findCommentsCtrl(w http.ResponseWriter, r *http.Request) {
return
}
render.Status(r, http.StatusOK)
render.JSON(w, r, comments)
renderJSONWithHTML(w, r, comments)
}
// GET /last/{max}?url=abc
@@ -185,7 +181,7 @@ func (s *Server) lastCommentsCtrl(w http.ResponseWriter, r *http.Request) {
}
render.Status(r, http.StatusOK)
render.JSON(w, r, comments)
renderJSONWithHTML(w, r, comments)
}
// GET /id/{id}?url=post-url
@@ -204,7 +200,7 @@ func (s *Server) commentByIDCtrl(w http.ResponseWriter, r *http.Request) {
}
render.Status(r, http.StatusOK)
render.JSON(w, r, comment)
renderJSONWithHTML(w, r, comment)
}
// GET /user
@@ -257,3 +253,19 @@ func httpError(w http.ResponseWriter, r *http.Request, code int, err error, deta
render.Status(r, code)
render.JSON(w, r, JSON{"error": err.Error(), "details": details})
}
// renderJSONWithHTML
//allows html tags
func renderJSONWithHTML(w http.ResponseWriter, r *http.Request, v interface{}) {
buf := &bytes.Buffer{}
enc := json.NewEncoder(buf)
if err := enc.Encode(v); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
if status, ok := r.Context().Value(render.StatusCtxKey).(int); ok {
w.WriteHeader(status)
}
_, _ = w.Write(buf.Bytes())
}
+1
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@@ -49,6 +49,7 @@ func (b *BoltDB) Create(comment Comment) (string, error) {
}
comment.Votes = make(map[string]bool)
comment = sanitizeComment(comment)
err := b.Update(func(tx *bolt.Tx) error {
bucket, e := tx.CreateBucketIfNotExists([]byte(comment.Locator.URL))
+2 -2
View File
@@ -18,7 +18,7 @@ func TestBoltDB_CreateAndFind(t *testing.T) {
res, err := b.Find(Request{Locator: Locator{URL: "https://radio-t.com"}})
assert.Nil(t, err)
assert.Equal(t, 2, len(res))
assert.Equal(t, "some text", res[0].Text)
assert.Equal(t, "some text, <a href=\"http://radio-t.com\" rel=\"nofollow\">link</a>", res[0].Text)
assert.Equal(t, "user1", res[0].User.ID)
t.Log(res[0].ID)
}
@@ -133,7 +133,7 @@ func prep(t *testing.T) *BoltDB {
b, err := NewBoltDB(testDb)
assert.Nil(t, err)
comment := Comment{Text: "some text", Timestamp: time.Date(2017, 12, 20, 15, 18, 22, 0, time.Local),
comment := Comment{Text: `some text, <a href="http://radio-t.com">link</a>`, Timestamp: time.Date(2017, 12, 20, 15, 18, 22, 0, time.Local),
Locator: Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, User: User{ID: "user1", Name: "user name"}}
_, err = b.Create(comment)
assert.Nil(t, err)
+14
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@@ -8,6 +8,10 @@ import (
"fmt"
"log"
"time"
"html/template"
"github.com/microcosm-cc/bluemonday"
)
// Comment represents a single comment with optional reference to its parent
@@ -71,3 +75,13 @@ func makeCommentID() string {
}
return fmt.Sprintf("%x", s.Sum(nil))
}
func sanitizeComment(comment Comment) Comment {
p := bluemonday.UGCPolicy()
comment.Text = p.Sanitize(comment.Text)
comment.User.ID = template.HTMLEscapeString(comment.User.ID)
comment.User.Name = template.HTMLEscapeString(comment.User.Name)
comment.User.Picture = p.Sanitize(comment.User.Picture)
comment.User.Profile = template.HTMLEscapeString(comment.User.Profile)
return comment
}
+51
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@@ -0,0 +1,51 @@
# Contributing to bluemonday
Third-party patches are essential for keeping bluemonday secure and offering the features developers want. However there are a few guidelines that we need contributors to follow so that we can maintain the quality of work that developers who use bluemonday expect.
## Getting Started
* Make sure you have a [Github account](https://github.com/signup/free)
## Guidelines
1. Do not vendor dependencies. As a security package, were we to vendor dependencies the projects that then vendor bluemonday may not receive the latest security updates to the dependencies. By not vendoring dependencies the project that implements bluemonday will vendor the latest version of any dependent packages. Vendoring is a project problem, not a package problem. bluemonday will be tested against the latest version of dependencies periodically and during any PR/merge.
## Submitting an Issue
* Submit a ticket for your issue, assuming one does not already exist
* Clearly describe the issue including the steps to reproduce (with sample input and output) if it is a bug
If you are reporting a security flaw, you may expect that we will provide the code to fix it for you. Otherwise you may want to submit a pull request to ensure the resolution is applied sooner rather than later:
* Fork the repository on Github
* Issue a pull request containing code to resolve the issue
## Submitting a Pull Request
* Submit a ticket for your issue, assuming one does not already exist
* Describe the reason for the pull request and if applicable show some example inputs and outputs to demonstrate what the patch does
* Fork the repository on Github
* Before submitting the pull request you should
1. Include tests for your patch, 1 test should encapsulate the entire patch and should refer to the Github issue
1. If you have added new exposed/public functionality, you should ensure it is documented appropriately
1. If you have added new exposed/public functionality, you should consider demonstrating how to use it within one of the helpers or shipped policies if appropriate or within a test if modifying a helper or policy is not appropriate
1. Run all of the tests `go test -v ./...` or `make test` and ensure all tests pass
1. Run gofmt `gofmt -w ./$*` or `make fmt`
1. Run vet `go tool vet *.go` or `make vet` and resolve any issues
1. Install golint using `go get -u github.com/golang/lint/golint` and run vet `golint *.go` or `make lint` and resolve every warning
* When submitting the pull request you should
1. Note the issue(s) it resolves, i.e. `Closes #6` in the pull request comment to close issue #6 when the pull request is accepted
Once you have submitted a pull request, we *may* merge it without changes. If we have any comments or feedback, or need you to make changes to your pull request we will update the Github pull request or the associated issue. We expect responses from you within two weeks, and we may close the pull request is there is no activity.
### Contributor Licence Agreement
We haven't gone for the formal "Sign a Contributor Licence Agreement" thing that projects like [puppet](https://cla.puppetlabs.com/), [Mojito](https://developer.yahoo.com/cocktails/mojito/cla/) and companies like [Google](http://code.google.com/legal/individual-cla-v1.0.html) are using.
But we do need to know that we can accept and merge your contributions, so for now the act of contributing a pull request should be considered equivalent to agreeing to a contributor licence agreement, specifically:
You accept that the act of submitting code to the bluemonday project is to grant a copyright licence to the project that is perpetual, worldwide, non-exclusive, no-charge, royalty free and irrevocable.
You accept that all who comply with the licence of the project (BSD 3-clause) are permitted to use your contributions to the project.
You accept, and by submitting code do declare, that you have the legal right to grant such a licence to the project and that each of the contributions is your own original creation.
+6
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@@ -0,0 +1,6 @@
1. Andrew Krasichkov @buglloc https://github.com/buglloc
1. John Graham-Cumming http://jgc.org/
1. Mike Samuel mikesamuel@gmail.com
1. Dmitri Shuralyov shurcooL@gmail.com
1. https://github.com/opennota
1. https://github.com/Gufran
+28
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@@ -0,0 +1,28 @@
Copyright (c) 2014, David Kitchen <david@buro9.com>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* Neither the name of the organisation (Microcosm) nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+42
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@@ -0,0 +1,42 @@
# Targets:
#
# all: Builds the code locally after testing
#
# fmt: Formats the source files
# build: Builds the code locally
# vet: Vets the code
# lint: Runs lint over the code (you do not need to fix everything)
# test: Runs the tests
# cover: Gives you the URL to a nice test coverage report
#
# install: Builds, tests and installs the code locally
.PHONY: all fmt build vet lint test cover install
# The first target is always the default action if `make` is called without
# args we build and install into $GOPATH so that it can just be run
all: fmt vet test install
fmt:
@gofmt -s -w ./$*
build:
@go build
vet:
@go vet *.go
lint:
@golint *.go
test:
@go test -v ./...
cover: COVERAGE_FILE := coverage.out
cover:
@go test -coverprofile=$(COVERAGE_FILE) && \
cover -html=$(COVERAGE_FILE) && rm $(COVERAGE_FILE)
install:
@go install ./...
+346
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@@ -0,0 +1,346 @@
# bluemonday [![Build Status](https://travis-ci.org/microcosm-cc/bluemonday.svg?branch=master)](https://travis-ci.org/microcosm-cc/bluemonday) [![GoDoc](https://godoc.org/github.com/microcosm-cc/bluemonday?status.png)](https://godoc.org/github.com/microcosm-cc/bluemonday) [![Sourcegraph](https://sourcegraph.com/github.com/microcosm-cc/bluemonday/-/badge.svg)](https://sourcegraph.com/github.com/microcosm-cc/bluemonday?badge)
bluemonday is a HTML sanitizer implemented in Go. It is fast and highly configurable.
bluemonday takes untrusted user generated content as an input, and will return HTML that has been sanitised against a whitelist of approved HTML elements and attributes so that you can safely include the content in your web page.
If you accept user generated content, and your server uses Go, you **need** bluemonday.
The default policy for user generated content (`bluemonday.UGCPolicy().Sanitize()`) turns this:
```html
Hello <STYLE>.XSS{background-image:url("javascript:alert('XSS')");}</STYLE><A CLASS=XSS></A>World
```
Into a harmless:
```html
Hello World
```
And it turns this:
```html
<a href="javascript:alert('XSS1')" onmouseover="alert('XSS2')">XSS<a>
```
Into this:
```html
XSS
```
Whilst still allowing this:
```html
<a href="http://www.google.com/">
<img src="https://ssl.gstatic.com/accounts/ui/logo_2x.png"/>
</a>
```
To pass through mostly unaltered (it gained a rel="nofollow" which is a good thing for user generated content):
```html
<a href="http://www.google.com/" rel="nofollow">
<img src="https://ssl.gstatic.com/accounts/ui/logo_2x.png"/>
</a>
```
It protects sites from [XSS](http://en.wikipedia.org/wiki/Cross-site_scripting) attacks. There are many [vectors for an XSS attack](https://www.owasp.org/index.php/XSS_Filter_Evasion_Cheat_Sheet) and the best way to mitigate the risk is to sanitize user input against a known safe list of HTML elements and attributes.
You should **always** run bluemonday **after** any other processing.
If you use [blackfriday](https://github.com/russross/blackfriday) or [Pandoc](http://johnmacfarlane.net/pandoc/) then bluemonday should be run after these steps. This ensures that no insecure HTML is introduced later in your process.
bluemonday is heavily inspired by both the [OWASP Java HTML Sanitizer](https://code.google.com/p/owasp-java-html-sanitizer/) and the [HTML Purifier](http://htmlpurifier.org/).
## Technical Summary
Whitelist based, you need to either build a policy describing the HTML elements and attributes to permit (and the `regexp` patterns of attributes), or use one of the supplied policies representing good defaults.
The policy containing the whitelist is applied using a fast non-validating, forward only, token-based parser implemented in the [Go net/html library](https://godoc.org/golang.org/x/net/html) by the core Go team.
We expect to be supplied with well-formatted HTML (closing elements for every applicable open element, nested correctly) and so we do not focus on repairing badly nested or incomplete HTML. We focus on simply ensuring that whatever elements do exist are described in the policy whitelist and that attributes and links are safe for use on your web page. [GIGO](http://en.wikipedia.org/wiki/Garbage_in,_garbage_out) does apply and if you feed it bad HTML bluemonday is not tasked with figuring out how to make it good again.
### Supported Go Versions
bluemonday is tested against Go 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and tip.
We do not support Go 1.0 as we depend on `golang.org/x/net/html` which includes a reference to `io.ErrNoProgress` which did not exist in Go 1.0.
## Is it production ready?
*Yes*
We are using bluemonday in production having migrated from the widely used and heavily field tested OWASP Java HTML Sanitizer.
We are passing our extensive test suite (including AntiSamy tests as well as tests for any issues raised). Check for any [unresolved issues](https://github.com/microcosm-cc/bluemonday/issues?page=1&state=open) to see whether anything may be a blocker for you.
We invite pull requests and issues to help us ensure we are offering comprehensive protection against various attacks via user generated content.
## Usage
Install in your `${GOPATH}` using `go get -u github.com/microcosm-cc/bluemonday`
Then call it:
```go
package main
import (
"fmt"
"github.com/microcosm-cc/bluemonday"
)
func main() {
p := bluemonday.UGCPolicy()
html := p.Sanitize(
`<a onblur="alert(secret)" href="http://www.google.com">Google</a>`,
)
// Output:
// <a href="http://www.google.com" rel="nofollow">Google</a>
fmt.Println(html)
}
```
We offer three ways to call Sanitize:
```go
p.Sanitize(string) string
p.SanitizeBytes([]byte) []byte
p.SanitizeReader(io.Reader) bytes.Buffer
```
If you are obsessed about performance, `p.SanitizeReader(r).Bytes()` will return a `[]byte` without performing any unnecessary casting of the inputs or outputs. Though the difference is so negligible you should never need to care.
You can build your own policies:
```go
package main
import (
"fmt"
"github.com/microcosm-cc/bluemonday"
)
func main() {
p := bluemonday.NewPolicy()
// Require URLs to be parseable by net/url.Parse and either:
// mailto: http:// or https://
p.AllowStandardURLs()
// We only allow <p> and <a href="">
p.AllowAttrs("href").OnElements("a")
p.AllowElements("p")
html := p.Sanitize(
`<a onblur="alert(secret)" href="http://www.google.com">Google</a>`,
)
// Output:
// <a href="http://www.google.com">Google</a>
fmt.Println(html)
}
```
We ship two default policies:
1. `bluemonday.StrictPolicy()` which can be thought of as equivalent to stripping all HTML elements and their attributes as it has nothing on it's whitelist. An example usage scenario would be blog post titles where HTML tags are not expected at all and if they are then the elements *and* the content of the elements should be stripped. This is a *very* strict policy.
2. `bluemonday.UGCPolicy()` which allows a broad selection of HTML elements and attributes that are safe for user generated content. Note that this policy does *not* whitelist iframes, object, embed, styles, script, etc. An example usage scenario would be blog post bodies where a variety of formatting is expected along with the potential for TABLEs and IMGs.
## Policy Building
The essence of building a policy is to determine which HTML elements and attributes are considered safe for your scenario. OWASP provide an [XSS prevention cheat sheet](https://www.owasp.org/index.php/XSS_(Cross_Site_Scripting)_Prevention_Cheat_Sheet) to help explain the risks, but essentially:
1. Avoid anything other than the standard HTML elements
1. Avoid `script`, `style`, `iframe`, `object`, `embed`, `base` elements that allow code to be executed by the client or third party content to be included that can execute code
1. Avoid anything other than plain HTML attributes with values matched to a regexp
Basically, you should be able to describe what HTML is fine for your scenario. If you do not have confidence that you can describe your policy please consider using one of the shipped policies such as `bluemonday.UGCPolicy()`.
To create a new policy:
```go
p := bluemonday.NewPolicy()
```
To add elements to a policy either add just the elements:
```go
p.AllowElements("b", "strong")
```
Or add elements as a virtue of adding an attribute:
```go
// Not the recommended pattern, see the recommendation on using .Matching() below
p.AllowAttrs("nowrap").OnElements("td", "th")
```
Attributes can either be added to all elements:
```go
p.AllowAttrs("dir").Matching(regexp.MustCompile("(?i)rtl|ltr")).Globally()
```
Or attributes can be added to specific elements:
```go
// Not the recommended pattern, see the recommendation on using .Matching() below
p.AllowAttrs("value").OnElements("li")
```
It is **always** recommended that an attribute be made to match a pattern. XSS in HTML attributes is very easy otherwise:
```go
// \p{L} matches unicode letters, \p{N} matches unicode numbers
p.AllowAttrs("title").Matching(regexp.MustCompile(`[\p{L}\p{N}\s\-_',:\[\]!\./\\\(\)&]*`)).Globally()
```
You can stop at any time and call .Sanitize():
```go
// string htmlIn passed in from a HTTP POST
htmlOut := p.Sanitize(htmlIn)
```
And you can take any existing policy and extend it:
```go
p := bluemonday.UGCPolicy()
p.AllowElements("fieldset", "select", "option")
```
### Links
Links are difficult beasts to sanitise safely and also one of the biggest attack vectors for malicious content.
It is possible to do this:
```go
p.AllowAttrs("href").Matching(regexp.MustCompile(`(?i)mailto|https?`)).OnElements("a")
```
But that will not protect you as the regular expression is insufficient in this case to have prevented a malformed value doing something unexpected.
We provide some additional global options for safely working with links.
`RequireParseableURLs` will ensure that URLs are parseable by Go's `net/url` package:
```go
p.RequireParseableURLs(true)
```
If you have enabled parseable URLs then the following option will `AllowRelativeURLs`. By default this is disabled (bluemonday is a whitelist tool... you need to explicitly tell us to permit things) and when disabled it will prevent all local and scheme relative URLs (i.e. `href="localpage.html"`, `href="../home.html"` and even `href="//www.google.com"` are relative):
```go
p.AllowRelativeURLs(true)
```
If you have enabled parseable URLs then you can whitelist the schemes (commonly called protocol when thinking of `http` and `https`) that are permitted. Bear in mind that allowing relative URLs in the above option will allow for a blank scheme:
```go
p.AllowURLSchemes("mailto", "http", "https")
```
Regardless of whether you have enabled parseable URLs, you can force all URLs to have a rel="nofollow" attribute. This will be added if it does not exist, but only when the `href` is valid:
```go
// This applies to "a" "area" "link" elements that have a "href" attribute
p.RequireNoFollowOnLinks(true)
```
We provide a convenience method that applies all of the above, but you will still need to whitelist the linkable elements for the URL rules to be applied to:
```go
p.AllowStandardURLs()
p.AllowAttrs("cite").OnElements("blockquote", "q")
p.AllowAttrs("href").OnElements("a", "area")
p.AllowAttrs("src").OnElements("img")
```
An additional complexity regarding links is the data URI as defined in [RFC2397](http://tools.ietf.org/html/rfc2397). The data URI allows for images to be served inline using this format:
```html
<img src="data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAAAAAAfQ//73v/+BiOh/AAA=">
```
We have provided a helper to verify the mimetype followed by base64 content of data URIs links:
```go
p.AllowDataURIImages()
```
That helper will enable GIF, JPEG, PNG and WEBP images.
It should be noted that there is a potential [security](http://palizine.plynt.com/issues/2010Oct/bypass-xss-filters/) [risk](https://capec.mitre.org/data/definitions/244.html) with the use of data URI links. You should only enable data URI links if you already trust the content.
We also have some features to help deal with user generated content:
```go
p.AddTargetBlankToFullyQualifiedLinks(true)
```
This will ensure that anchor `<a href="" />` links that are fully qualified (the href destination includes a host name) will get `target="_blank"` added to them.
Additionally any link that has `target="_blank"` after the policy has been applied will also have the `rel` attribute adjusted to add `noopener`. This means a link may start like `<a href="//host/path"/>` and will end up as `<a href="//host/path" rel="noopener" target="_blank">`. It is important to note that the addition of `noopener` is a security feature and not an issue. There is an unfortunate feature to browsers that a browser window opened as a result of `target="_blank"` can still control the opener (your web page) and this protects against that. The background to this can be found here: [https://dev.to/ben/the-targetblank-vulnerability-by-example](https://dev.to/ben/the-targetblank-vulnerability-by-example)
### Policy Building Helpers
We also bundle some helpers to simplify policy building:
```go
// Permits the "dir", "id", "lang", "title" attributes globally
p.AllowStandardAttributes()
// Permits the "img" element and it's standard attributes
p.AllowImages()
// Permits ordered and unordered lists, and also definition lists
p.AllowLists()
// Permits HTML tables and all applicable elements and non-styling attributes
p.AllowTables()
```
### Invalid Instructions
The following are invalid:
```go
// This does not say where the attributes are allowed, you need to add
// .Globally() or .OnElements(...)
// This will be ignored without error.
p.AllowAttrs("value")
// This does not say where the attributes are allowed, you need to add
// .Globally() or .OnElements(...)
// This will be ignored without error.
p.AllowAttrs(
"type",
).Matching(
regexp.MustCompile("(?i)^(circle|disc|square|a|A|i|I|1)$"),
)
```
Both examples exhibit the same issue, they declare attributes but do not then specify whether they are whitelisted globally or only on specific elements (and which elements). Attributes belong to one or more elements, and the policy needs to declare this.
## Limitations
We are not yet including any tools to help whitelist and sanitize CSS. Which means that unless you wish to do the heavy lifting in a single regular expression (inadvisable), **you should not allow the "style" attribute anywhere**.
It is not the job of bluemonday to fix your bad HTML, it is merely the job of bluemonday to prevent malicious HTML getting through. If you have mismatched HTML elements, or non-conforming nesting of elements, those will remain. But if you have well-structured HTML bluemonday will not break it.
## TODO
* Add support for CSS sanitisation to allow some CSS properties based on a whitelist, possibly using the [Gorilla CSS3 scanner](http://www.gorillatoolkit.org/pkg/css/scanner) - PRs welcome so long as testing covers XSS and demonstrates safety first
* Investigate whether devs want to blacklist elements and attributes. This would allow devs to take an existing policy (such as the `bluemonday.UGCPolicy()` ) that encapsulates 90% of what they're looking for but does more than they need, and to remove the extra things they do not want to make it 100% what they want
* Investigate whether devs want a validating HTML mode, in which the HTML elements are not just transformed into a balanced tree (every start tag has a closing tag at the correct depth) but also that elements and character data appear only in their allowed context (i.e. that a `table` element isn't a descendent of a `caption`, that `colgroup`, `thead`, `tbody`, `tfoot` and `tr` are permitted, and that character data is not permitted)
## Development
If you have cloned this repo you will probably need the dependency:
`go get golang.org/x/net/html`
Gophers can use their familiar tools:
`go build`
`go test`
I personally use a Makefile as it spares typing the same args over and over whilst providing consistency for those of us who jump from language to language and enjoy just typing `make` in a project directory and watch magic happen.
`make` will build, vet, test and install the library.
`make clean` will remove the library from a *single* `${GOPATH}/pkg` directory tree
`make test` will run the tests
`make cover` will run the tests and *open a browser window* with the coverage report
`make lint` will run golint (install via `go get github.com/golang/lint/golint`)
## Long term goals
1. Open the code to adversarial peer review similar to the [Attack Review Ground Rules](https://code.google.com/p/owasp-java-html-sanitizer/wiki/AttackReviewGroundRules)
1. Raise funds and pay for an external security review
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// Copyright (c) 2014, David Kitchen <david@buro9.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of the organisation (Microcosm) nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
/*
Package bluemonday provides a way of describing a whitelist of HTML elements
and attributes as a policy, and for that policy to be applied to untrusted
strings from users that may contain markup. All elements and attributes not on
the whitelist will be stripped.
The default bluemonday.UGCPolicy().Sanitize() turns this:
Hello <STYLE>.XSS{background-image:url("javascript:alert('XSS')");}</STYLE><A CLASS=XSS></A>World
Into the more harmless:
Hello World
And it turns this:
<a href="javascript:alert('XSS1')" onmouseover="alert('XSS2')">XSS<a>
Into this:
XSS
Whilst still allowing this:
<a href="http://www.google.com/">
<img src="https://ssl.gstatic.com/accounts/ui/logo_2x.png"/>
</a>
To pass through mostly unaltered (it gained a rel="nofollow"):
<a href="http://www.google.com/" rel="nofollow">
<img src="https://ssl.gstatic.com/accounts/ui/logo_2x.png"/>
</a>
The primary purpose of bluemonday is to take potentially unsafe user generated
content (from things like Markdown, HTML WYSIWYG tools, etc) and make it safe
for you to put on your website.
It protects sites against XSS (http://en.wikipedia.org/wiki/Cross-site_scripting)
and other malicious content that a user interface may deliver. There are many
vectors for an XSS attack (https://www.owasp.org/index.php/XSS_Filter_Evasion_Cheat_Sheet)
and the safest thing to do is to sanitize user input against a known safe list
of HTML elements and attributes.
Note: You should always run bluemonday after any other processing.
If you use blackfriday (https://github.com/russross/blackfriday) or
Pandoc (http://johnmacfarlane.net/pandoc/) then bluemonday should be run after
these steps. This ensures that no insecure HTML is introduced later in your
process.
bluemonday is heavily inspired by both the OWASP Java HTML Sanitizer
(https://code.google.com/p/owasp-java-html-sanitizer/) and the HTML Purifier
(http://htmlpurifier.org/).
We ship two default policies, one is bluemonday.StrictPolicy() and can be
thought of as equivalent to stripping all HTML elements and their attributes as
it has nothing on it's whitelist.
The other is bluemonday.UGCPolicy() and allows a broad selection of HTML
elements and attributes that are safe for user generated content. Note that
this policy does not whitelist iframes, object, embed, styles, script, etc.
The essence of building a policy is to determine which HTML elements and
attributes are considered safe for your scenario. OWASP provide an XSS
prevention cheat sheet ( https://www.google.com/search?q=xss+prevention+cheat+sheet )
to help explain the risks, but essentially:
1. Avoid whitelisting anything other than plain HTML elements
2. Avoid whitelisting `script`, `style`, `iframe`, `object`, `embed`, `base`
elements
3. Avoid whitelisting anything other than plain HTML elements with simple
values that you can match to a regexp
*/
package bluemonday
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// Copyright (c) 2014, David Kitchen <david@buro9.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of the organisation (Microcosm) nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package bluemonday
import (
"encoding/base64"
"net/url"
"regexp"
)
// A selection of regular expressions that can be used as .Matching() rules on
// HTML attributes.
var (
// CellAlign handles the `align` attribute
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/td#attr-align
CellAlign = regexp.MustCompile(`(?i)^(center|justify|left|right|char)$`)
// CellVerticalAlign handles the `valign` attribute
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/td#attr-valign
CellVerticalAlign = regexp.MustCompile(`(?i)^(baseline|bottom|middle|top)$`)
// Direction handles the `dir` attribute
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/bdo#attr-dir
Direction = regexp.MustCompile(`(?i)^(rtl|ltr)$`)
// ImageAlign handles the `align` attribute on the `image` tag
// http://www.w3.org/MarkUp/Test/Img/imgtest.html
ImageAlign = regexp.MustCompile(
`(?i)^(left|right|top|texttop|middle|absmiddle|baseline|bottom|absbottom)$`,
)
// Integer describes whole positive integers (including 0) used in places
// like td.colspan
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/td#attr-colspan
Integer = regexp.MustCompile(`^[0-9]+$`)
// ISO8601 according to the W3 group is only a subset of the ISO8601
// standard: http://www.w3.org/TR/NOTE-datetime
//
// Used in places like time.datetime
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/time#attr-datetime
//
// Matches patterns:
// Year:
// YYYY (eg 1997)
// Year and month:
// YYYY-MM (eg 1997-07)
// Complete date:
// YYYY-MM-DD (eg 1997-07-16)
// Complete date plus hours and minutes:
// YYYY-MM-DDThh:mmTZD (eg 1997-07-16T19:20+01:00)
// Complete date plus hours, minutes and seconds:
// YYYY-MM-DDThh:mm:ssTZD (eg 1997-07-16T19:20:30+01:00)
// Complete date plus hours, minutes, seconds and a decimal fraction of a
// second
// YYYY-MM-DDThh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)
ISO8601 = regexp.MustCompile(
`^[0-9]{4}(-[0-9]{2}(-[0-9]{2}([ T][0-9]{2}(:[0-9]{2}){1,2}(.[0-9]{1,6})` +
`?Z?([\+-][0-9]{2}:[0-9]{2})?)?)?)?$`,
)
// ListType encapsulates the common value as well as the latest spec
// values for lists
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ol#attr-type
ListType = regexp.MustCompile(`(?i)^(circle|disc|square|a|A|i|I|1)$`)
// SpaceSeparatedTokens is used in places like `a.rel` and the common attribute
// `class` which both contain space delimited lists of data tokens
// http://www.w3.org/TR/html-markup/datatypes.html#common.data.tokens-def
// Regexp: \p{L} matches unicode letters, \p{N} matches unicode numbers
SpaceSeparatedTokens = regexp.MustCompile(`^([\s\p{L}\p{N}_-]+)$`)
// Number is a double value used on HTML5 meter and progress elements
// http://www.whatwg.org/specs/web-apps/current-work/multipage/the-button-element.html#the-meter-element
Number = regexp.MustCompile(`^[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?$`)
// NumberOrPercent is used predominantly as units of measurement in width
// and height attributes
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#attr-height
NumberOrPercent = regexp.MustCompile(`^[0-9]+[%]?$`)
// Paragraph of text in an attribute such as *.'title', img.alt, etc
// https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes#attr-title
// Note that we are not allowing chars that could close tags like '>'
Paragraph = regexp.MustCompile(`^[\p{L}\p{N}\s\-_',\[\]!\./\\\(\)]*$`)
// dataURIImagePrefix is used by AllowDataURIImages to define the acceptable
// prefix of data URIs that contain common web image formats.
//
// This is not exported as it's not useful by itself, and only has value
// within the AllowDataURIImages func
dataURIImagePrefix = regexp.MustCompile(
`^image/(gif|jpeg|png|webp);base64,`,
)
)
// AllowStandardURLs is a convenience function that will enable rel="nofollow"
// on "a", "area" and "link" (if you have allowed those elements) and will
// ensure that the URL values are parseable and either relative or belong to the
// "mailto", "http", or "https" schemes
func (p *Policy) AllowStandardURLs() {
// URLs must be parseable by net/url.Parse()
p.RequireParseableURLs(true)
// !url.IsAbs() is permitted
p.AllowRelativeURLs(true)
// Most common URL schemes only
p.AllowURLSchemes("mailto", "http", "https")
// For all anchors we will add rel="nofollow" if it does not already exist
// This applies to "a" "area" "link"
p.RequireNoFollowOnLinks(true)
}
// AllowStandardAttributes will enable "id", "title" and the language specific
// attributes "dir" and "lang" on all elements that are whitelisted
func (p *Policy) AllowStandardAttributes() {
// "dir" "lang" are permitted as both language attributes affect charsets
// and direction of text.
p.AllowAttrs("dir").Matching(Direction).Globally()
p.AllowAttrs(
"lang",
).Matching(regexp.MustCompile(`[a-zA-Z]{2,20}`)).Globally()
// "id" is permitted. This is pretty much as some HTML elements require this
// to work well ("dfn" is an example of a "id" being value)
// This does create a risk that JavaScript and CSS within your web page
// might identify the wrong elements. Ensure that you select things
// accurately
p.AllowAttrs("id").Matching(
regexp.MustCompile(`[a-zA-Z0-9\:\-_\.]+`),
).Globally()
// "title" is permitted as it improves accessibility.
p.AllowAttrs("title").Matching(Paragraph).Globally()
}
// AllowStyling presently enables the class attribute globally.
//
// Note: When bluemonday ships a CSS parser and we can safely sanitise that,
// this will also allow sanitized styling of elements via the style attribute.
func (p *Policy) AllowStyling() {
// "class" is permitted globally
p.AllowAttrs("class").Matching(SpaceSeparatedTokens).Globally()
}
// AllowImages enables the img element and some popular attributes. It will also
// ensure that URL values are parseable. This helper does not enable data URI
// images, for that you should also use the AllowDataURIImages() helper.
func (p *Policy) AllowImages() {
// "img" is permitted
p.AllowAttrs("align").Matching(ImageAlign).OnElements("img")
p.AllowAttrs("alt").Matching(Paragraph).OnElements("img")
p.AllowAttrs("height", "width").Matching(NumberOrPercent).OnElements("img")
// Standard URLs enabled
p.AllowStandardURLs()
p.AllowAttrs("src").OnElements("img")
}
// AllowDataURIImages permits the use of inline images defined in RFC2397
// http://tools.ietf.org/html/rfc2397
// http://en.wikipedia.org/wiki/Data_URI_scheme
//
// Images must have a mimetype matching:
// image/gif
// image/jpeg
// image/png
// image/webp
//
// NOTE: There is a potential security risk to allowing data URIs and you should
// only permit them on content you already trust.
// http://palizine.plynt.com/issues/2010Oct/bypass-xss-filters/
// https://capec.mitre.org/data/definitions/244.html
func (p *Policy) AllowDataURIImages() {
// URLs must be parseable by net/url.Parse()
p.RequireParseableURLs(true)
// Supply a function to validate images contained within data URI
p.AllowURLSchemeWithCustomPolicy(
"data",
func(url *url.URL) (allowUrl bool) {
if url.RawQuery != "" || url.Fragment != "" {
return false
}
matched := dataURIImagePrefix.FindString(url.Opaque)
if matched == "" {
return false
}
_, err := base64.StdEncoding.DecodeString(url.Opaque[len(matched):])
if err != nil {
return false
}
return true
},
)
}
// AllowLists will enabled ordered and unordered lists, as well as definition
// lists
func (p *Policy) AllowLists() {
// "ol" "ul" are permitted
p.AllowAttrs("type").Matching(ListType).OnElements("ol", "ul")
// "li" is permitted
p.AllowAttrs("type").Matching(ListType).OnElements("li")
p.AllowAttrs("value").Matching(Integer).OnElements("li")
// "dl" "dt" "dd" are permitted
p.AllowElements("dl", "dt", "dd")
}
// AllowTables will enable a rich set of elements and attributes to describe
// HTML tables
func (p *Policy) AllowTables() {
// "table" is permitted
p.AllowAttrs("height", "width").Matching(NumberOrPercent).OnElements("table")
p.AllowAttrs("summary").Matching(Paragraph).OnElements("table")
// "caption" is permitted
p.AllowElements("caption")
// "col" "colgroup" are permitted
p.AllowAttrs("align").Matching(CellAlign).OnElements("col", "colgroup")
p.AllowAttrs("height", "width").Matching(
NumberOrPercent,
).OnElements("col", "colgroup")
p.AllowAttrs("span").Matching(Integer).OnElements("colgroup", "col")
p.AllowAttrs("valign").Matching(
CellVerticalAlign,
).OnElements("col", "colgroup")
// "thead" "tr" are permitted
p.AllowAttrs("align").Matching(CellAlign).OnElements("thead", "tr")
p.AllowAttrs("valign").Matching(CellVerticalAlign).OnElements("thead", "tr")
// "td" "th" are permitted
p.AllowAttrs("abbr").Matching(Paragraph).OnElements("td", "th")
p.AllowAttrs("align").Matching(CellAlign).OnElements("td", "th")
p.AllowAttrs("colspan", "rowspan").Matching(Integer).OnElements("td", "th")
p.AllowAttrs("headers").Matching(
SpaceSeparatedTokens,
).OnElements("td", "th")
p.AllowAttrs("height", "width").Matching(
NumberOrPercent,
).OnElements("td", "th")
p.AllowAttrs(
"scope",
).Matching(
regexp.MustCompile(`(?i)(?:row|col)(?:group)?`),
).OnElements("td", "th")
p.AllowAttrs("valign").Matching(CellVerticalAlign).OnElements("td", "th")
p.AllowAttrs("nowrap").Matching(
regexp.MustCompile(`(?i)|nowrap`),
).OnElements("td", "th")
// "tbody" "tfoot"
p.AllowAttrs("align").Matching(CellAlign).OnElements("tbody", "tfoot")
p.AllowAttrs("valign").Matching(
CellVerticalAlign,
).OnElements("tbody", "tfoot")
}
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// Copyright (c) 2014, David Kitchen <david@buro9.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of the organisation (Microcosm) nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package bluemonday
import (
"regexp"
)
// StrictPolicy returns an empty policy, which will effectively strip all HTML
// elements and their attributes from a document.
func StrictPolicy() *Policy {
return NewPolicy()
}
// StripTagsPolicy is DEPRECATED. Use StrictPolicy instead.
func StripTagsPolicy() *Policy {
return StrictPolicy()
}
// UGCPolicy returns a policy aimed at user generated content that is a result
// of HTML WYSIWYG tools and Markdown conversions.
//
// This is expected to be a fairly rich document where as much markup as
// possible should be retained. Markdown permits raw HTML so we are basically
// providing a policy to sanitise HTML5 documents safely but with the
// least intrusion on the formatting expectations of the user.
func UGCPolicy() *Policy {
p := NewPolicy()
///////////////////////
// Global attributes //
///////////////////////
// "class" is not permitted as we are not allowing users to style their own
// content
p.AllowStandardAttributes()
//////////////////////////////
// Global URL format policy //
//////////////////////////////
p.AllowStandardURLs()
////////////////////////////////
// Declarations and structure //
////////////////////////////////
// "xml" "xslt" "DOCTYPE" "html" "head" are not permitted as we are
// expecting user generated content to be a fragment of HTML and not a full
// document.
//////////////////////////
// Sectioning root tags //
//////////////////////////
// "article" and "aside" are permitted and takes no attributes
p.AllowElements("article", "aside")
// "body" is not permitted as we are expecting user generated content to be a fragment
// of HTML and not a full document.
// "details" is permitted, including the "open" attribute which can either
// be blank or the value "open".
p.AllowAttrs(
"open",
).Matching(regexp.MustCompile(`(?i)^(|open)$`)).OnElements("details")
// "fieldset" is not permitted as we are not allowing forms to be created.
// "figure" is permitted and takes no attributes
p.AllowElements("figure")
// "nav" is not permitted as it is assumed that the site (and not the user)
// has defined navigation elements
// "section" is permitted and takes no attributes
p.AllowElements("section")
// "summary" is permitted and takes no attributes
p.AllowElements("summary")
//////////////////////////
// Headings and footers //
//////////////////////////
// "footer" is not permitted as we expect user content to be a fragment and
// not structural to this extent
// "h1" through "h6" are permitted and take no attributes
p.AllowElements("h1", "h2", "h3", "h4", "h5", "h6")
// "header" is not permitted as we expect user content to be a fragment and
// not structural to this extent
// "hgroup" is permitted and takes no attributes
p.AllowElements("hgroup")
/////////////////////////////////////
// Content grouping and separating //
/////////////////////////////////////
// "blockquote" is permitted, including the "cite" attribute which must be
// a standard URL.
p.AllowAttrs("cite").OnElements("blockquote")
// "br" "div" "hr" "p" "span" "wbr" are permitted and take no attributes
p.AllowElements("br", "div", "hr", "p", "span", "wbr")
///////////
// Links //
///////////
// "a" is permitted
p.AllowAttrs("href").OnElements("a")
// "area" is permitted along with the attributes that map image maps work
p.AllowAttrs("name").Matching(
regexp.MustCompile(`^([\p{L}\p{N}_-]+)$`),
).OnElements("map")
p.AllowAttrs("alt").Matching(Paragraph).OnElements("area")
p.AllowAttrs("coords").Matching(
regexp.MustCompile(`^([0-9]+,)+[0-9]+$`),
).OnElements("area")
p.AllowAttrs("href").OnElements("area")
p.AllowAttrs("rel").Matching(SpaceSeparatedTokens).OnElements("area")
p.AllowAttrs("shape").Matching(
regexp.MustCompile(`(?i)^(default|circle|rect|poly)$`),
).OnElements("area")
p.AllowAttrs("usemap").Matching(
regexp.MustCompile(`(?i)^#[\p{L}\p{N}_-]+$`),
).OnElements("img")
// "link" is not permitted
/////////////////////
// Phrase elements //
/////////////////////
// The following are all inline phrasing elements
p.AllowElements("abbr", "acronym", "cite", "code", "dfn", "em",
"figcaption", "mark", "s", "samp", "strong", "sub", "sup", "var")
// "q" is permitted and "cite" is a URL and handled by URL policies
p.AllowAttrs("cite").OnElements("q")
// "time" is permitted
p.AllowAttrs("datetime").Matching(ISO8601).OnElements("time")
////////////////////
// Style elements //
////////////////////
// block and inline elements that impart no semantic meaning but style the
// document
p.AllowElements("b", "i", "pre", "small", "strike", "tt", "u")
// "style" is not permitted as we are not yet sanitising CSS and it is an
// XSS attack vector
//////////////////////
// HTML5 Formatting //
//////////////////////
// "bdi" "bdo" are permitted
p.AllowAttrs("dir").Matching(Direction).OnElements("bdi", "bdo")
// "rp" "rt" "ruby" are permitted
p.AllowElements("rp", "rt", "ruby")
///////////////////////////
// HTML5 Change tracking //
///////////////////////////
// "del" "ins" are permitted
p.AllowAttrs("cite").Matching(Paragraph).OnElements("del", "ins")
p.AllowAttrs("datetime").Matching(ISO8601).OnElements("del", "ins")
///////////
// Lists //
///////////
p.AllowLists()
////////////
// Tables //
////////////
p.AllowTables()
///////////
// Forms //
///////////
// By and large, forms are not permitted. However there are some form
// elements that can be used to present data, and we do permit those
//
// "button" "fieldset" "input" "keygen" "label" "output" "select" "datalist"
// "textarea" "optgroup" "option" are all not permitted
// "meter" is permitted
p.AllowAttrs(
"value",
"min",
"max",
"low",
"high",
"optimum",
).Matching(Number).OnElements("meter")
// "progress" is permitted
p.AllowAttrs("value", "max").Matching(Number).OnElements("progress")
//////////////////////
// Embedded content //
//////////////////////
// Vast majority not permitted
// "audio" "canvas" "embed" "iframe" "object" "param" "source" "svg" "track"
// "video" are all not permitted
p.AllowImages()
return p
}
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// Copyright (c) 2014, David Kitchen <david@buro9.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of the organisation (Microcosm) nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package bluemonday
import (
"net/url"
"regexp"
"strings"
)
// Policy encapsulates the whitelist of HTML elements and attributes that will
// be applied to the sanitised HTML.
//
// You should use bluemonday.NewPolicy() to create a blank policy as the
// unexported fields contain maps that need to be initialized.
type Policy struct {
// Declares whether the maps have been initialized, used as a cheap check to
// ensure that those using Policy{} directly won't cause nil pointer
// exceptions
initialized bool
// If true then we add spaces when stripping tags, specifically the closing
// tag is replaced by a space character.
addSpaces bool
// When true, add rel="nofollow" to HTML anchors
requireNoFollow bool
// When true, add rel="nofollow" to HTML anchors
// Will add for href="http://foo"
// Will skip for href="/foo" or href="foo"
requireNoFollowFullyQualifiedLinks bool
// When true add target="_blank" to fully qualified links
// Will add for href="http://foo"
// Will skip for href="/foo" or href="foo"
addTargetBlankToFullyQualifiedLinks bool
// When true, URLs must be parseable by "net/url" url.Parse()
requireParseableURLs bool
// When true, u, _ := url.Parse("url"); !u.IsAbs() is permitted
allowRelativeURLs bool
// map[htmlElementName]map[htmlAttributeName]attrPolicy
elsAndAttrs map[string]map[string]attrPolicy
// map[htmlAttributeName]attrPolicy
globalAttrs map[string]attrPolicy
// If urlPolicy is nil, all URLs with matching schema are allowed.
// Otherwise, only the URLs with matching schema and urlPolicy(url)
// returning true are allowed.
allowURLSchemes map[string]urlPolicy
// If an element has had all attributes removed as a result of a policy
// being applied, then the element would be removed from the output.
//
// However some elements are valid and have strong layout meaning without
// any attributes, i.e. <table>. To prevent those being removed we maintain
// a list of elements that are allowed to have no attributes and that will
// be maintained in the output HTML.
setOfElementsAllowedWithoutAttrs map[string]struct{}
setOfElementsToSkipContent map[string]struct{}
}
type attrPolicy struct {
// optional pattern to match, when not nil the regexp needs to match
// otherwise the attribute is removed
regexp *regexp.Regexp
}
type attrPolicyBuilder struct {
p *Policy
attrNames []string
regexp *regexp.Regexp
allowEmpty bool
}
type urlPolicy func(url *url.URL) (allowUrl bool)
// init initializes the maps if this has not been done already
func (p *Policy) init() {
if !p.initialized {
p.elsAndAttrs = make(map[string]map[string]attrPolicy)
p.globalAttrs = make(map[string]attrPolicy)
p.allowURLSchemes = make(map[string]urlPolicy)
p.setOfElementsAllowedWithoutAttrs = make(map[string]struct{})
p.setOfElementsToSkipContent = make(map[string]struct{})
p.initialized = true
}
}
// NewPolicy returns a blank policy with nothing whitelisted or permitted. This
// is the recommended way to start building a policy and you should now use
// AllowAttrs() and/or AllowElements() to construct the whitelist of HTML
// elements and attributes.
func NewPolicy() *Policy {
p := Policy{}
p.addDefaultElementsWithoutAttrs()
p.addDefaultSkipElementContent()
return &p
}
// AllowAttrs takes a range of HTML attribute names and returns an
// attribute policy builder that allows you to specify the pattern and scope of
// the whitelisted attribute.
//
// The attribute policy is only added to the core policy when either Globally()
// or OnElements(...) are called.
func (p *Policy) AllowAttrs(attrNames ...string) *attrPolicyBuilder {
p.init()
abp := attrPolicyBuilder{
p: p,
allowEmpty: false,
}
for _, attrName := range attrNames {
abp.attrNames = append(abp.attrNames, strings.ToLower(attrName))
}
return &abp
}
// AllowNoAttrs says that attributes on element are optional.
//
// The attribute policy is only added to the core policy when OnElements(...)
// are called.
func (p *Policy) AllowNoAttrs() *attrPolicyBuilder {
p.init()
abp := attrPolicyBuilder{
p: p,
allowEmpty: true,
}
return &abp
}
// AllowNoAttrs says that attributes on element are optional.
//
// The attribute policy is only added to the core policy when OnElements(...)
// are called.
func (abp *attrPolicyBuilder) AllowNoAttrs() *attrPolicyBuilder {
abp.allowEmpty = true
return abp
}
// Matching allows a regular expression to be applied to a nascent attribute
// policy, and returns the attribute policy. Calling this more than once will
// replace the existing regexp.
func (abp *attrPolicyBuilder) Matching(regex *regexp.Regexp) *attrPolicyBuilder {
abp.regexp = regex
return abp
}
// OnElements will bind an attribute policy to a given range of HTML elements
// and return the updated policy
func (abp *attrPolicyBuilder) OnElements(elements ...string) *Policy {
for _, element := range elements {
element = strings.ToLower(element)
for _, attr := range abp.attrNames {
if _, ok := abp.p.elsAndAttrs[element]; !ok {
abp.p.elsAndAttrs[element] = make(map[string]attrPolicy)
}
ap := attrPolicy{}
if abp.regexp != nil {
ap.regexp = abp.regexp
}
abp.p.elsAndAttrs[element][attr] = ap
}
if abp.allowEmpty {
abp.p.setOfElementsAllowedWithoutAttrs[element] = struct{}{}
if _, ok := abp.p.elsAndAttrs[element]; !ok {
abp.p.elsAndAttrs[element] = make(map[string]attrPolicy)
}
}
}
return abp.p
}
// Globally will bind an attribute policy to all HTML elements and return the
// updated policy
func (abp *attrPolicyBuilder) Globally() *Policy {
for _, attr := range abp.attrNames {
if _, ok := abp.p.globalAttrs[attr]; !ok {
abp.p.globalAttrs[attr] = attrPolicy{}
}
ap := attrPolicy{}
if abp.regexp != nil {
ap.regexp = abp.regexp
}
abp.p.globalAttrs[attr] = ap
}
return abp.p
}
// AllowElements will append HTML elements to the whitelist without applying an
// attribute policy to those elements (the elements are permitted
// sans-attributes)
func (p *Policy) AllowElements(names ...string) *Policy {
p.init()
for _, element := range names {
element = strings.ToLower(element)
if _, ok := p.elsAndAttrs[element]; !ok {
p.elsAndAttrs[element] = make(map[string]attrPolicy)
}
}
return p
}
// RequireNoFollowOnLinks will result in all <a> tags having a rel="nofollow"
// added to them if one does not already exist
//
// Note: This requires p.RequireParseableURLs(true) and will enable it.
func (p *Policy) RequireNoFollowOnLinks(require bool) *Policy {
p.requireNoFollow = require
p.requireParseableURLs = true
return p
}
// RequireNoFollowOnFullyQualifiedLinks will result in all <a> tags that point
// to a non-local destination (i.e. starts with a protocol and has a host)
// having a rel="nofollow" added to them if one does not already exist
//
// Note: This requires p.RequireParseableURLs(true) and will enable it.
func (p *Policy) RequireNoFollowOnFullyQualifiedLinks(require bool) *Policy {
p.requireNoFollowFullyQualifiedLinks = require
p.requireParseableURLs = true
return p
}
// AddTargetBlankToFullyQualifiedLinks will result in all <a> tags that point
// to a non-local destination (i.e. starts with a protocol and has a host)
// having a target="_blank" added to them if one does not already exist
//
// Note: This requires p.RequireParseableURLs(true) and will enable it.
func (p *Policy) AddTargetBlankToFullyQualifiedLinks(require bool) *Policy {
p.addTargetBlankToFullyQualifiedLinks = require
p.requireParseableURLs = true
return p
}
// RequireParseableURLs will result in all URLs requiring that they be parseable
// by "net/url" url.Parse()
// This applies to:
// - a.href
// - area.href
// - blockquote.cite
// - img.src
// - link.href
// - script.src
func (p *Policy) RequireParseableURLs(require bool) *Policy {
p.requireParseableURLs = require
return p
}
// AllowRelativeURLs enables RequireParseableURLs and then permits URLs that
// are parseable, have no schema information and url.IsAbs() returns false
// This permits local URLs
func (p *Policy) AllowRelativeURLs(require bool) *Policy {
p.RequireParseableURLs(true)
p.allowRelativeURLs = require
return p
}
// AllowURLSchemes will append URL schemes to the whitelist
// Example: p.AllowURLSchemes("mailto", "http", "https")
func (p *Policy) AllowURLSchemes(schemes ...string) *Policy {
p.init()
p.RequireParseableURLs(true)
for _, scheme := range schemes {
scheme = strings.ToLower(scheme)
// Allow all URLs with matching scheme.
p.allowURLSchemes[scheme] = nil
}
return p
}
// AllowURLSchemeWithCustomPolicy will append URL schemes with
// a custom URL policy to the whitelist.
// Only the URLs with matching schema and urlPolicy(url)
// returning true will be allowed.
func (p *Policy) AllowURLSchemeWithCustomPolicy(
scheme string,
urlPolicy func(url *url.URL) (allowUrl bool),
) *Policy {
p.init()
p.RequireParseableURLs(true)
scheme = strings.ToLower(scheme)
p.allowURLSchemes[scheme] = urlPolicy
return p
}
// AddSpaceWhenStrippingTag states whether to add a single space " " when
// removing tags that are not whitelisted by the policy.
//
// This is useful if you expect to strip tags in dense markup and may lose the
// value of whitespace.
//
// For example: "<p>Hello</p><p>World</p>"" would be sanitized to "HelloWorld"
// with the default value of false, but you may wish to sanitize this to
// " Hello World " by setting AddSpaceWhenStrippingTag to true as this would
// retain the intent of the text.
func (p *Policy) AddSpaceWhenStrippingTag(allow bool) *Policy {
p.addSpaces = allow
return p
}
// SkipElementsContent adds the HTML elements whose tags is needed to be removed
// with it's content.
func (p *Policy) SkipElementsContent(names ...string) *Policy {
p.init()
for _, element := range names {
element = strings.ToLower(element)
if _, ok := p.setOfElementsToSkipContent[element]; !ok {
p.setOfElementsToSkipContent[element] = struct{}{}
}
}
return p
}
// AllowElementsContent marks the HTML elements whose content should be
// retained after removing the tag.
func (p *Policy) AllowElementsContent(names ...string) *Policy {
p.init()
for _, element := range names {
delete(p.setOfElementsToSkipContent, strings.ToLower(element))
}
return p
}
// addDefaultElementsWithoutAttrs adds the HTML elements that we know are valid
// without any attributes to an internal map.
// i.e. we know that <table> is valid, but <bdo> isn't valid as the "dir" attr
// is mandatory
func (p *Policy) addDefaultElementsWithoutAttrs() {
p.init()
p.setOfElementsAllowedWithoutAttrs["abbr"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["acronym"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["article"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["aside"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["audio"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["b"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["bdi"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["blockquote"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["body"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["br"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["button"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["canvas"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["caption"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["center"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["cite"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["code"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["col"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["colgroup"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["datalist"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["dd"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["del"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["details"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["dfn"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["div"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["dl"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["dt"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["em"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["fieldset"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["figcaption"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["figure"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["footer"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h1"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h2"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h3"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h4"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h5"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["h6"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["head"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["header"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["hgroup"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["hr"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["html"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["i"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["ins"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["kbd"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["li"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["mark"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["marquee"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["nav"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["ol"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["optgroup"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["option"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["p"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["pre"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["q"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["rp"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["rt"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["ruby"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["s"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["samp"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["script"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["section"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["select"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["small"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["span"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["strike"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["strong"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["style"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["sub"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["summary"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["sup"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["svg"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["table"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["tbody"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["td"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["textarea"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["tfoot"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["th"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["thead"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["title"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["time"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["tr"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["tt"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["u"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["ul"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["var"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["video"] = struct{}{}
p.setOfElementsAllowedWithoutAttrs["wbr"] = struct{}{}
}
// addDefaultSkipElementContent adds the HTML elements that we should skip
// rendering the character content of, if the element itself is not allowed.
// This is all character data that the end user would not normally see.
// i.e. if we exclude a <script> tag then we shouldn't render the JavaScript or
// anything else until we encounter the closing </script> tag.
func (p *Policy) addDefaultSkipElementContent() {
p.init()
p.setOfElementsToSkipContent["frame"] = struct{}{}
p.setOfElementsToSkipContent["frameset"] = struct{}{}
p.setOfElementsToSkipContent["iframe"] = struct{}{}
p.setOfElementsToSkipContent["noembed"] = struct{}{}
p.setOfElementsToSkipContent["noframes"] = struct{}{}
p.setOfElementsToSkipContent["noscript"] = struct{}{}
p.setOfElementsToSkipContent["nostyle"] = struct{}{}
p.setOfElementsToSkipContent["object"] = struct{}{}
p.setOfElementsToSkipContent["script"] = struct{}{}
p.setOfElementsToSkipContent["style"] = struct{}{}
p.setOfElementsToSkipContent["title"] = struct{}{}
}
+547
View File
@@ -0,0 +1,547 @@
// Copyright (c) 2014, David Kitchen <david@buro9.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of the organisation (Microcosm) nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package bluemonday
import (
"bytes"
"io"
"net/url"
"strings"
"golang.org/x/net/html"
)
// Sanitize takes a string that contains a HTML fragment or document and applies
// the given policy whitelist.
//
// It returns a HTML string that has been sanitized by the policy or an empty
// string if an error has occurred (most likely as a consequence of extremely
// malformed input)
func (p *Policy) Sanitize(s string) string {
if strings.TrimSpace(s) == "" {
return s
}
return p.sanitize(strings.NewReader(s)).String()
}
// SanitizeBytes takes a []byte that contains a HTML fragment or document and applies
// the given policy whitelist.
//
// It returns a []byte containing the HTML that has been sanitized by the policy
// or an empty []byte if an error has occurred (most likely as a consequence of
// extremely malformed input)
func (p *Policy) SanitizeBytes(b []byte) []byte {
if len(bytes.TrimSpace(b)) == 0 {
return b
}
return p.sanitize(bytes.NewReader(b)).Bytes()
}
// SanitizeReader takes an io.Reader that contains a HTML fragment or document
// and applies the given policy whitelist.
//
// It returns a bytes.Buffer containing the HTML that has been sanitized by the
// policy. Errors during sanitization will merely return an empty result.
func (p *Policy) SanitizeReader(r io.Reader) *bytes.Buffer {
return p.sanitize(r)
}
// Performs the actual sanitization process.
func (p *Policy) sanitize(r io.Reader) *bytes.Buffer {
// It is possible that the developer has created the policy via:
// p := bluemonday.Policy{}
// rather than:
// p := bluemonday.NewPolicy()
// If this is the case, and if they haven't yet triggered an action that
// would initiliaze the maps, then we need to do that.
p.init()
var (
buff bytes.Buffer
skipElementContent bool
skippingElementsCount int64
skipClosingTag bool
closingTagToSkipStack []string
mostRecentlyStartedToken string
)
tokenizer := html.NewTokenizer(r)
for {
if tokenizer.Next() == html.ErrorToken {
err := tokenizer.Err()
if err == io.EOF {
// End of input means end of processing
return &buff
}
// Raw tokenizer error
return &bytes.Buffer{}
}
token := tokenizer.Token()
switch token.Type {
case html.DoctypeToken:
// DocType is not handled as there is no safe parsing mechanism
// provided by golang.org/x/net/html for the content, and this can
// be misused to insert HTML tags that are not then sanitized
//
// One might wish to recursively sanitize here using the same policy
// but I will need to do some further testing before considering
// this.
case html.CommentToken:
// Comments are ignored by default
case html.StartTagToken:
mostRecentlyStartedToken = token.Data
aps, ok := p.elsAndAttrs[token.Data]
if !ok {
if _, ok := p.setOfElementsToSkipContent[token.Data]; ok {
skipElementContent = true
skippingElementsCount++
}
if p.addSpaces {
buff.WriteString(" ")
}
break
}
if len(token.Attr) != 0 {
token.Attr = p.sanitizeAttrs(token.Data, token.Attr, aps)
}
if len(token.Attr) == 0 {
if !p.allowNoAttrs(token.Data) {
skipClosingTag = true
closingTagToSkipStack = append(closingTagToSkipStack, token.Data)
if p.addSpaces {
buff.WriteString(" ")
}
break
}
}
if !skipElementContent {
buff.WriteString(token.String())
}
case html.EndTagToken:
if mostRecentlyStartedToken == token.Data {
mostRecentlyStartedToken = ""
}
if skipClosingTag && closingTagToSkipStack[len(closingTagToSkipStack)-1] == token.Data {
closingTagToSkipStack = closingTagToSkipStack[:len(closingTagToSkipStack)-1]
if len(closingTagToSkipStack) == 0 {
skipClosingTag = false
}
if p.addSpaces {
buff.WriteString(" ")
}
break
}
if _, ok := p.elsAndAttrs[token.Data]; !ok {
if _, ok := p.setOfElementsToSkipContent[token.Data]; ok {
skippingElementsCount--
if skippingElementsCount == 0 {
skipElementContent = false
}
}
if p.addSpaces {
buff.WriteString(" ")
}
break
}
if !skipElementContent {
buff.WriteString(token.String())
}
case html.SelfClosingTagToken:
aps, ok := p.elsAndAttrs[token.Data]
if !ok {
if p.addSpaces {
buff.WriteString(" ")
}
break
}
if len(token.Attr) != 0 {
token.Attr = p.sanitizeAttrs(token.Data, token.Attr, aps)
}
if len(token.Attr) == 0 && !p.allowNoAttrs(token.Data) {
if p.addSpaces {
buff.WriteString(" ")
}
break
}
if !skipElementContent {
buff.WriteString(token.String())
}
case html.TextToken:
if !skipElementContent {
switch mostRecentlyStartedToken {
case "script":
// not encouraged, but if a policy allows JavaScript we
// should not HTML escape it as that would break the output
buff.WriteString(token.Data)
case "style":
// not encouraged, but if a policy allows CSS styles we
// should not HTML escape it as that would break the output
buff.WriteString(token.Data)
default:
// HTML escape the text
buff.WriteString(token.String())
}
}
default:
// A token that didn't exist in the html package when we wrote this
return &bytes.Buffer{}
}
}
}
// sanitizeAttrs takes a set of element attribute policies and the global
// attribute policies and applies them to the []html.Attribute returning a set
// of html.Attributes that match the policies
func (p *Policy) sanitizeAttrs(
elementName string,
attrs []html.Attribute,
aps map[string]attrPolicy,
) []html.Attribute {
if len(attrs) == 0 {
return attrs
}
// Builds a new attribute slice based on the whether the attribute has been
// whitelisted explicitly or globally.
cleanAttrs := []html.Attribute{}
for _, htmlAttr := range attrs {
// Is there an element specific attribute policy that applies?
if ap, ok := aps[htmlAttr.Key]; ok {
if ap.regexp != nil {
if ap.regexp.MatchString(htmlAttr.Val) {
cleanAttrs = append(cleanAttrs, htmlAttr)
continue
}
} else {
cleanAttrs = append(cleanAttrs, htmlAttr)
continue
}
}
// Is there a global attribute policy that applies?
if ap, ok := p.globalAttrs[htmlAttr.Key]; ok {
if ap.regexp != nil {
if ap.regexp.MatchString(htmlAttr.Val) {
cleanAttrs = append(cleanAttrs, htmlAttr)
}
} else {
cleanAttrs = append(cleanAttrs, htmlAttr)
}
}
}
if len(cleanAttrs) == 0 {
// If nothing was allowed, let's get out of here
return cleanAttrs
}
// cleanAttrs now contains the attributes that are permitted
if linkable(elementName) {
if p.requireParseableURLs {
// Ensure URLs are parseable:
// - a.href
// - area.href
// - link.href
// - blockquote.cite
// - q.cite
// - img.src
// - script.src
tmpAttrs := []html.Attribute{}
for _, htmlAttr := range cleanAttrs {
switch elementName {
case "a", "area", "link":
if htmlAttr.Key == "href" {
if u, ok := p.validURL(htmlAttr.Val); ok {
htmlAttr.Val = u
tmpAttrs = append(tmpAttrs, htmlAttr)
}
break
}
tmpAttrs = append(tmpAttrs, htmlAttr)
case "blockquote", "q":
if htmlAttr.Key == "cite" {
if u, ok := p.validURL(htmlAttr.Val); ok {
htmlAttr.Val = u
tmpAttrs = append(tmpAttrs, htmlAttr)
}
break
}
tmpAttrs = append(tmpAttrs, htmlAttr)
case "img", "script":
if htmlAttr.Key == "src" {
if u, ok := p.validURL(htmlAttr.Val); ok {
htmlAttr.Val = u
tmpAttrs = append(tmpAttrs, htmlAttr)
}
break
}
tmpAttrs = append(tmpAttrs, htmlAttr)
default:
tmpAttrs = append(tmpAttrs, htmlAttr)
}
}
cleanAttrs = tmpAttrs
}
if (p.requireNoFollow ||
p.requireNoFollowFullyQualifiedLinks ||
p.addTargetBlankToFullyQualifiedLinks) &&
len(cleanAttrs) > 0 {
// Add rel="nofollow" if a "href" exists
switch elementName {
case "a", "area", "link":
var hrefFound bool
var externalLink bool
for _, htmlAttr := range cleanAttrs {
if htmlAttr.Key == "href" {
hrefFound = true
u, err := url.Parse(htmlAttr.Val)
if err != nil {
continue
}
if u.Host != "" {
externalLink = true
}
continue
}
}
if hrefFound {
var (
noFollowFound bool
targetBlankFound bool
)
addNoFollow := (p.requireNoFollow ||
externalLink && p.requireNoFollowFullyQualifiedLinks)
addTargetBlank := (externalLink &&
p.addTargetBlankToFullyQualifiedLinks)
tmpAttrs := []html.Attribute{}
for _, htmlAttr := range cleanAttrs {
var appended bool
if htmlAttr.Key == "rel" && addNoFollow {
if strings.Contains(htmlAttr.Val, "nofollow") {
noFollowFound = true
tmpAttrs = append(tmpAttrs, htmlAttr)
appended = true
} else {
htmlAttr.Val += " nofollow"
noFollowFound = true
tmpAttrs = append(tmpAttrs, htmlAttr)
appended = true
}
}
if elementName == "a" && htmlAttr.Key == "target" {
if htmlAttr.Val == "_blank" {
targetBlankFound = true
}
if addTargetBlank && !targetBlankFound {
htmlAttr.Val = "_blank"
targetBlankFound = true
tmpAttrs = append(tmpAttrs, htmlAttr)
appended = true
}
}
if !appended {
tmpAttrs = append(tmpAttrs, htmlAttr)
}
}
if noFollowFound || targetBlankFound {
cleanAttrs = tmpAttrs
}
if addNoFollow && !noFollowFound {
rel := html.Attribute{}
rel.Key = "rel"
rel.Val = "nofollow"
cleanAttrs = append(cleanAttrs, rel)
}
if elementName == "a" && addTargetBlank && !targetBlankFound {
rel := html.Attribute{}
rel.Key = "target"
rel.Val = "_blank"
targetBlankFound = true
cleanAttrs = append(cleanAttrs, rel)
}
if targetBlankFound {
// target="_blank" has a security risk that allows the
// opened window/tab to issue JavaScript calls against
// window.opener, which in effect allow the destination
// of the link to control the source:
// https://dev.to/ben/the-targetblank-vulnerability-by-example
//
// To mitigate this risk, we need to add a specific rel
// attribute if it is not already present.
// rel="noopener"
//
// Unfortunately this is processing the rel twice (we
// already looked at it earlier ^^) as we cannot be sure
// of the ordering of the href and rel, and whether we
// have fully satisfied that we need to do this. This
// double processing only happens *if* target="_blank"
// is true.
var noOpenerAdded bool
tmpAttrs := []html.Attribute{}
for _, htmlAttr := range cleanAttrs {
var appended bool
if htmlAttr.Key == "rel" {
if strings.Contains(htmlAttr.Val, "noopener") {
noOpenerAdded = true
tmpAttrs = append(tmpAttrs, htmlAttr)
} else {
htmlAttr.Val += " noopener"
noOpenerAdded = true
tmpAttrs = append(tmpAttrs, htmlAttr)
}
appended = true
}
if !appended {
tmpAttrs = append(tmpAttrs, htmlAttr)
}
}
if noOpenerAdded {
cleanAttrs = tmpAttrs
} else {
// rel attr was not found, or else noopener would
// have been added already
rel := html.Attribute{}
rel.Key = "rel"
rel.Val = "noopener"
cleanAttrs = append(cleanAttrs, rel)
}
}
}
default:
}
}
}
return cleanAttrs
}
func (p *Policy) allowNoAttrs(elementName string) bool {
_, ok := p.setOfElementsAllowedWithoutAttrs[elementName]
return ok
}
func (p *Policy) validURL(rawurl string) (string, bool) {
if p.requireParseableURLs {
// URLs are valid if when space is trimmed the URL is valid
rawurl = strings.TrimSpace(rawurl)
// URLs cannot contain whitespace, unless it is a data-uri
if (strings.Contains(rawurl, " ") ||
strings.Contains(rawurl, "\t") ||
strings.Contains(rawurl, "\n")) &&
!strings.HasPrefix(rawurl, `data:`) {
return "", false
}
// URLs are valid if they parse
u, err := url.Parse(rawurl)
if err != nil {
return "", false
}
if u.Scheme != "" {
urlPolicy, ok := p.allowURLSchemes[u.Scheme]
if !ok {
return "", false
}
if urlPolicy == nil || urlPolicy(u) == true {
return u.String(), true
}
return "", false
}
if p.allowRelativeURLs {
if u.String() != "" {
return u.String(), true
}
}
return "", false
}
return rawurl, true
}
func linkable(elementName string) bool {
switch elementName {
case "a", "area", "blockquote", "img", "link", "script":
return true
default:
return false
}
}
+78
View File
@@ -0,0 +1,78 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package atom provides integer codes (also known as atoms) for a fixed set of
// frequently occurring HTML strings: tag names and attribute keys such as "p"
// and "id".
//
// Sharing an atom's name between all elements with the same tag can result in
// fewer string allocations when tokenizing and parsing HTML. Integer
// comparisons are also generally faster than string comparisons.
//
// The value of an atom's particular code is not guaranteed to stay the same
// between versions of this package. Neither is any ordering guaranteed:
// whether atom.H1 < atom.H2 may also change. The codes are not guaranteed to
// be dense. The only guarantees are that e.g. looking up "div" will yield
// atom.Div, calling atom.Div.String will return "div", and atom.Div != 0.
package atom // import "golang.org/x/net/html/atom"
// Atom is an integer code for a string. The zero value maps to "".
type Atom uint32
// String returns the atom's name.
func (a Atom) String() string {
start := uint32(a >> 8)
n := uint32(a & 0xff)
if start+n > uint32(len(atomText)) {
return ""
}
return atomText[start : start+n]
}
func (a Atom) string() string {
return atomText[a>>8 : a>>8+a&0xff]
}
// fnv computes the FNV hash with an arbitrary starting value h.
func fnv(h uint32, s []byte) uint32 {
for i := range s {
h ^= uint32(s[i])
h *= 16777619
}
return h
}
func match(s string, t []byte) bool {
for i, c := range t {
if s[i] != c {
return false
}
}
return true
}
// Lookup returns the atom whose name is s. It returns zero if there is no
// such atom. The lookup is case sensitive.
func Lookup(s []byte) Atom {
if len(s) == 0 || len(s) > maxAtomLen {
return 0
}
h := fnv(hash0, s)
if a := table[h&uint32(len(table)-1)]; int(a&0xff) == len(s) && match(a.string(), s) {
return a
}
if a := table[(h>>16)&uint32(len(table)-1)]; int(a&0xff) == len(s) && match(a.string(), s) {
return a
}
return 0
}
// String returns a string whose contents are equal to s. In that sense, it is
// equivalent to string(s) but may be more efficient.
func String(s []byte) string {
if a := Lookup(s); a != 0 {
return a.String()
}
return string(s)
}
+709
View File
@@ -0,0 +1,709 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
//go:generate go run gen.go
//go:generate go run gen.go -test
package main
import (
"bytes"
"flag"
"fmt"
"go/format"
"io/ioutil"
"math/rand"
"os"
"sort"
"strings"
)
// identifier converts s to a Go exported identifier.
// It converts "div" to "Div" and "accept-charset" to "AcceptCharset".
func identifier(s string) string {
b := make([]byte, 0, len(s))
cap := true
for _, c := range s {
if c == '-' {
cap = true
continue
}
if cap && 'a' <= c && c <= 'z' {
c -= 'a' - 'A'
}
cap = false
b = append(b, byte(c))
}
return string(b)
}
var test = flag.Bool("test", false, "generate table_test.go")
func genFile(name string, buf *bytes.Buffer) {
b, err := format.Source(buf.Bytes())
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
if err := ioutil.WriteFile(name, b, 0644); err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
func main() {
flag.Parse()
var all []string
all = append(all, elements...)
all = append(all, attributes...)
all = append(all, eventHandlers...)
all = append(all, extra...)
sort.Strings(all)
// uniq - lists have dups
w := 0
for _, s := range all {
if w == 0 || all[w-1] != s {
all[w] = s
w++
}
}
all = all[:w]
if *test {
var buf bytes.Buffer
fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
fmt.Fprintln(&buf, "//go:generate go run gen.go -test\n")
fmt.Fprintln(&buf, "package atom\n")
fmt.Fprintln(&buf, "var testAtomList = []string{")
for _, s := range all {
fmt.Fprintf(&buf, "\t%q,\n", s)
}
fmt.Fprintln(&buf, "}")
genFile("table_test.go", &buf)
return
}
// Find hash that minimizes table size.
var best *table
for i := 0; i < 1000000; i++ {
if best != nil && 1<<(best.k-1) < len(all) {
break
}
h := rand.Uint32()
for k := uint(0); k <= 16; k++ {
if best != nil && k >= best.k {
break
}
var t table
if t.init(h, k, all) {
best = &t
break
}
}
}
if best == nil {
fmt.Fprintf(os.Stderr, "failed to construct string table\n")
os.Exit(1)
}
// Lay out strings, using overlaps when possible.
layout := append([]string{}, all...)
// Remove strings that are substrings of other strings
for changed := true; changed; {
changed = false
for i, s := range layout {
if s == "" {
continue
}
for j, t := range layout {
if i != j && t != "" && strings.Contains(s, t) {
changed = true
layout[j] = ""
}
}
}
}
// Join strings where one suffix matches another prefix.
for {
// Find best i, j, k such that layout[i][len-k:] == layout[j][:k],
// maximizing overlap length k.
besti := -1
bestj := -1
bestk := 0
for i, s := range layout {
if s == "" {
continue
}
for j, t := range layout {
if i == j {
continue
}
for k := bestk + 1; k <= len(s) && k <= len(t); k++ {
if s[len(s)-k:] == t[:k] {
besti = i
bestj = j
bestk = k
}
}
}
}
if bestk > 0 {
layout[besti] += layout[bestj][bestk:]
layout[bestj] = ""
continue
}
break
}
text := strings.Join(layout, "")
atom := map[string]uint32{}
for _, s := range all {
off := strings.Index(text, s)
if off < 0 {
panic("lost string " + s)
}
atom[s] = uint32(off<<8 | len(s))
}
var buf bytes.Buffer
// Generate the Go code.
fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n")
fmt.Fprintln(&buf, "//go:generate go run gen.go\n")
fmt.Fprintln(&buf, "package atom\n\nconst (")
// compute max len
maxLen := 0
for _, s := range all {
if maxLen < len(s) {
maxLen = len(s)
}
fmt.Fprintf(&buf, "\t%s Atom = %#x\n", identifier(s), atom[s])
}
fmt.Fprintln(&buf, ")\n")
fmt.Fprintf(&buf, "const hash0 = %#x\n\n", best.h0)
fmt.Fprintf(&buf, "const maxAtomLen = %d\n\n", maxLen)
fmt.Fprintf(&buf, "var table = [1<<%d]Atom{\n", best.k)
for i, s := range best.tab {
if s == "" {
continue
}
fmt.Fprintf(&buf, "\t%#x: %#x, // %s\n", i, atom[s], s)
}
fmt.Fprintf(&buf, "}\n")
datasize := (1 << best.k) * 4
fmt.Fprintln(&buf, "const atomText =")
textsize := len(text)
for len(text) > 60 {
fmt.Fprintf(&buf, "\t%q +\n", text[:60])
text = text[60:]
}
fmt.Fprintf(&buf, "\t%q\n\n", text)
genFile("table.go", &buf)
fmt.Fprintf(os.Stdout, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize)
}
type byLen []string
func (x byLen) Less(i, j int) bool { return len(x[i]) > len(x[j]) }
func (x byLen) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byLen) Len() int { return len(x) }
// fnv computes the FNV hash with an arbitrary starting value h.
func fnv(h uint32, s string) uint32 {
for i := 0; i < len(s); i++ {
h ^= uint32(s[i])
h *= 16777619
}
return h
}
// A table represents an attempt at constructing the lookup table.
// The lookup table uses cuckoo hashing, meaning that each string
// can be found in one of two positions.
type table struct {
h0 uint32
k uint
mask uint32
tab []string
}
// hash returns the two hashes for s.
func (t *table) hash(s string) (h1, h2 uint32) {
h := fnv(t.h0, s)
h1 = h & t.mask
h2 = (h >> 16) & t.mask
return
}
// init initializes the table with the given parameters.
// h0 is the initial hash value,
// k is the number of bits of hash value to use, and
// x is the list of strings to store in the table.
// init returns false if the table cannot be constructed.
func (t *table) init(h0 uint32, k uint, x []string) bool {
t.h0 = h0
t.k = k
t.tab = make([]string, 1<<k)
t.mask = 1<<k - 1
for _, s := range x {
if !t.insert(s) {
return false
}
}
return true
}
// insert inserts s in the table.
func (t *table) insert(s string) bool {
h1, h2 := t.hash(s)
if t.tab[h1] == "" {
t.tab[h1] = s
return true
}
if t.tab[h2] == "" {
t.tab[h2] = s
return true
}
if t.push(h1, 0) {
t.tab[h1] = s
return true
}
if t.push(h2, 0) {
t.tab[h2] = s
return true
}
return false
}
// push attempts to push aside the entry in slot i.
func (t *table) push(i uint32, depth int) bool {
if depth > len(t.tab) {
return false
}
s := t.tab[i]
h1, h2 := t.hash(s)
j := h1 + h2 - i
if t.tab[j] != "" && !t.push(j, depth+1) {
return false
}
t.tab[j] = s
return true
}
// The lists of element names and attribute keys were taken from
// https://html.spec.whatwg.org/multipage/indices.html#index
// as of the "HTML Living Standard - Last Updated 18 September 2017" version.
// "command", "keygen" and "menuitem" have been removed from the spec,
// but are kept here for backwards compatibility.
var elements = []string{
"a",
"abbr",
"address",
"area",
"article",
"aside",
"audio",
"b",
"base",
"bdi",
"bdo",
"blockquote",
"body",
"br",
"button",
"canvas",
"caption",
"cite",
"code",
"col",
"colgroup",
"command",
"data",
"datalist",
"dd",
"del",
"details",
"dfn",
"dialog",
"div",
"dl",
"dt",
"em",
"embed",
"fieldset",
"figcaption",
"figure",
"footer",
"form",
"h1",
"h2",
"h3",
"h4",
"h5",
"h6",
"head",
"header",
"hgroup",
"hr",
"html",
"i",
"iframe",
"img",
"input",
"ins",
"kbd",
"keygen",
"label",
"legend",
"li",
"link",
"main",
"map",
"mark",
"menu",
"menuitem",
"meta",
"meter",
"nav",
"noscript",
"object",
"ol",
"optgroup",
"option",
"output",
"p",
"param",
"picture",
"pre",
"progress",
"q",
"rp",
"rt",
"ruby",
"s",
"samp",
"script",
"section",
"select",
"slot",
"small",
"source",
"span",
"strong",
"style",
"sub",
"summary",
"sup",
"table",
"tbody",
"td",
"template",
"textarea",
"tfoot",
"th",
"thead",
"time",
"title",
"tr",
"track",
"u",
"ul",
"var",
"video",
"wbr",
}
// https://html.spec.whatwg.org/multipage/indices.html#attributes-3
//
// "challenge", "command", "contextmenu", "dropzone", "icon", "keytype", "mediagroup",
// "radiogroup", "spellcheck", "scoped", "seamless", "sortable" and "sorted" have been removed from the spec,
// but are kept here for backwards compatibility.
var attributes = []string{
"abbr",
"accept",
"accept-charset",
"accesskey",
"action",
"allowfullscreen",
"allowpaymentrequest",
"allowusermedia",
"alt",
"as",
"async",
"autocomplete",
"autofocus",
"autoplay",
"challenge",
"charset",
"checked",
"cite",
"class",
"color",
"cols",
"colspan",
"command",
"content",
"contenteditable",
"contextmenu",
"controls",
"coords",
"crossorigin",
"data",
"datetime",
"default",
"defer",
"dir",
"dirname",
"disabled",
"download",
"draggable",
"dropzone",
"enctype",
"for",
"form",
"formaction",
"formenctype",
"formmethod",
"formnovalidate",
"formtarget",
"headers",
"height",
"hidden",
"high",
"href",
"hreflang",
"http-equiv",
"icon",
"id",
"inputmode",
"integrity",
"is",
"ismap",
"itemid",
"itemprop",
"itemref",
"itemscope",
"itemtype",
"keytype",
"kind",
"label",
"lang",
"list",
"loop",
"low",
"manifest",
"max",
"maxlength",
"media",
"mediagroup",
"method",
"min",
"minlength",
"multiple",
"muted",
"name",
"nomodule",
"nonce",
"novalidate",
"open",
"optimum",
"pattern",
"ping",
"placeholder",
"playsinline",
"poster",
"preload",
"radiogroup",
"readonly",
"referrerpolicy",
"rel",
"required",
"reversed",
"rows",
"rowspan",
"sandbox",
"spellcheck",
"scope",
"scoped",
"seamless",
"selected",
"shape",
"size",
"sizes",
"sortable",
"sorted",
"slot",
"span",
"spellcheck",
"src",
"srcdoc",
"srclang",
"srcset",
"start",
"step",
"style",
"tabindex",
"target",
"title",
"translate",
"type",
"typemustmatch",
"updateviacache",
"usemap",
"value",
"width",
"workertype",
"wrap",
}
// "onautocomplete", "onautocompleteerror", "onmousewheel",
// "onshow" and "onsort" have been removed from the spec,
// but are kept here for backwards compatibility.
var eventHandlers = []string{
"onabort",
"onautocomplete",
"onautocompleteerror",
"onauxclick",
"onafterprint",
"onbeforeprint",
"onbeforeunload",
"onblur",
"oncancel",
"oncanplay",
"oncanplaythrough",
"onchange",
"onclick",
"onclose",
"oncontextmenu",
"oncopy",
"oncuechange",
"oncut",
"ondblclick",
"ondrag",
"ondragend",
"ondragenter",
"ondragexit",
"ondragleave",
"ondragover",
"ondragstart",
"ondrop",
"ondurationchange",
"onemptied",
"onended",
"onerror",
"onfocus",
"onhashchange",
"oninput",
"oninvalid",
"onkeydown",
"onkeypress",
"onkeyup",
"onlanguagechange",
"onload",
"onloadeddata",
"onloadedmetadata",
"onloadend",
"onloadstart",
"onmessage",
"onmessageerror",
"onmousedown",
"onmouseenter",
"onmouseleave",
"onmousemove",
"onmouseout",
"onmouseover",
"onmouseup",
"onmousewheel",
"onwheel",
"onoffline",
"ononline",
"onpagehide",
"onpageshow",
"onpaste",
"onpause",
"onplay",
"onplaying",
"onpopstate",
"onprogress",
"onratechange",
"onreset",
"onresize",
"onrejectionhandled",
"onscroll",
"onsecuritypolicyviolation",
"onseeked",
"onseeking",
"onselect",
"onshow",
"onsort",
"onstalled",
"onstorage",
"onsubmit",
"onsuspend",
"ontimeupdate",
"ontoggle",
"onunhandledrejection",
"onunload",
"onvolumechange",
"onwaiting",
}
// extra are ad-hoc values not covered by any of the lists above.
var extra = []string{
"align",
"annotation",
"annotation-xml",
"applet",
"basefont",
"bgsound",
"big",
"blink",
"center",
"color",
"desc",
"face",
"font",
"foreignObject", // HTML is case-insensitive, but SVG-embedded-in-HTML is case-sensitive.
"foreignobject",
"frame",
"frameset",
"image",
"isindex",
"listing",
"malignmark",
"marquee",
"math",
"mglyph",
"mi",
"mn",
"mo",
"ms",
"mtext",
"nobr",
"noembed",
"noframes",
"plaintext",
"prompt",
"public",
"spacer",
"strike",
"svg",
"system",
"tt",
"xmp",
}
+777
View File
@@ -0,0 +1,777 @@
// Code generated by go generate gen.go; DO NOT EDIT.
//go:generate go run gen.go
package atom
const (
A Atom = 0x1
Abbr Atom = 0x4
Accept Atom = 0x1a06
AcceptCharset Atom = 0x1a0e
Accesskey Atom = 0x2c09
Action Atom = 0x25a06
Address Atom = 0x6ed07
Align Atom = 0x6d405
Allowfullscreen Atom = 0x1f00f
Allowpaymentrequest Atom = 0x6913
Allowusermedia Atom = 0x850e
Alt Atom = 0xb003
Annotation Atom = 0x1b90a
AnnotationXml Atom = 0x1b90e
Applet Atom = 0x30106
Area Atom = 0x34a04
Article Atom = 0x3f007
As Atom = 0xb902
Aside Atom = 0xc105
Async Atom = 0xb905
Audio Atom = 0xcf05
Autocomplete Atom = 0x2600c
Autofocus Atom = 0xeb09
Autoplay Atom = 0x10608
B Atom = 0x101
Base Atom = 0x11504
Basefont Atom = 0x11508
Bdi Atom = 0x16103
Bdo Atom = 0x13403
Bgsound Atom = 0x14707
Big Atom = 0x15903
Blink Atom = 0x15c05
Blockquote Atom = 0x1680a
Body Atom = 0x2804
Br Atom = 0x202
Button Atom = 0x17206
Canvas Atom = 0xbd06
Caption Atom = 0x21907
Center Atom = 0x20806
Challenge Atom = 0x28309
Charset Atom = 0x2107
Checked Atom = 0x46d07
Cite Atom = 0x55804
Class Atom = 0x5b905
Code Atom = 0x19004
Col Atom = 0x19703
Colgroup Atom = 0x19708
Color Atom = 0x1af05
Cols Atom = 0x1b404
Colspan Atom = 0x1b407
Command Atom = 0x1c707
Content Atom = 0x57f07
Contenteditable Atom = 0x57f0f
Contextmenu Atom = 0x3740b
Controls Atom = 0x1ce08
Coords Atom = 0x1da06
Crossorigin Atom = 0x1e30b
Data Atom = 0x49904
Datalist Atom = 0x49908
Datetime Atom = 0x2a008
Dd Atom = 0x2bf02
Default Atom = 0xc407
Defer Atom = 0x19205
Del Atom = 0x44603
Desc Atom = 0x55504
Details Atom = 0x4607
Dfn Atom = 0x5f03
Dialog Atom = 0x16206
Dir Atom = 0xa303
Dirname Atom = 0xa307
Disabled Atom = 0x14d08
Div Atom = 0x15403
Dl Atom = 0x5e202
Download Atom = 0x45708
Draggable Atom = 0x18309
Dropzone Atom = 0x3f908
Dt Atom = 0x64702
Em Atom = 0x4202
Embed Atom = 0x4205
Enctype Atom = 0x27507
Face Atom = 0x20604
Fieldset Atom = 0x20e08
Figcaption Atom = 0x2160a
Figure Atom = 0x23006
Font Atom = 0x11904
Footer Atom = 0xb306
For Atom = 0x23c03
ForeignObject Atom = 0x23c0d
Foreignobject Atom = 0x2490d
Form Atom = 0x25604
Formaction Atom = 0x2560a
Formenctype Atom = 0x2710b
Formmethod Atom = 0x28c0a
Formnovalidate Atom = 0x2960e
Formtarget Atom = 0x2a80a
Frame Atom = 0x5705
Frameset Atom = 0x5708
H1 Atom = 0x14502
H2 Atom = 0x2c602
H3 Atom = 0x2f502
H4 Atom = 0x33902
H5 Atom = 0x34302
H6 Atom = 0x64902
Head Atom = 0x32504
Header Atom = 0x32506
Headers Atom = 0x32507
Height Atom = 0x12c06
Hgroup Atom = 0x2b206
Hidden Atom = 0x2bd06
High Atom = 0x2c304
Hr Atom = 0x14002
Href Atom = 0x2c804
Hreflang Atom = 0x2c808
Html Atom = 0x13004
HttpEquiv Atom = 0x2d00a
I Atom = 0x601
Icon Atom = 0x57e04
Id Atom = 0xc302
Iframe Atom = 0x2e406
Image Atom = 0x2ea05
Img Atom = 0x2ef03
Input Atom = 0x43f05
Inputmode Atom = 0x43f09
Ins Atom = 0x1ec03
Integrity Atom = 0x22709
Is Atom = 0x14e02
Isindex Atom = 0x2f707
Ismap Atom = 0x2fe05
Itemid Atom = 0x37f06
Itemprop Atom = 0x55908
Itemref Atom = 0x3c107
Itemscope Atom = 0x66d09
Itemtype Atom = 0x30708
Kbd Atom = 0x16003
Keygen Atom = 0x3206
Keytype Atom = 0x7e07
Kind Atom = 0x18004
Label Atom = 0xda05
Lang Atom = 0x2cc04
Legend Atom = 0x18a06
Li Atom = 0x11102
Link Atom = 0x15d04
List Atom = 0x49d04
Listing Atom = 0x49d07
Loop Atom = 0xde04
Low Atom = 0x6b03
Main Atom = 0x1004
Malignmark Atom = 0x6d30a
Manifest Atom = 0x30f08
Map Atom = 0x30003
Mark Atom = 0x6d904
Marquee Atom = 0x31b07
Math Atom = 0x32204
Max Atom = 0x33103
Maxlength Atom = 0x33109
Media Atom = 0x8e05
Mediagroup Atom = 0x8e0a
Menu Atom = 0x37b04
Menuitem Atom = 0x37b08
Meta Atom = 0x4ac04
Meter Atom = 0xa805
Method Atom = 0x29006
Mglyph Atom = 0x2f006
Mi Atom = 0x33b02
Min Atom = 0x33b03
Minlength Atom = 0x33b09
Mn Atom = 0x29902
Mo Atom = 0x6302
Ms Atom = 0x67002
Mtext Atom = 0x34505
Multiple Atom = 0x35308
Muted Atom = 0x35b05
Name Atom = 0xa604
Nav Atom = 0x1303
Nobr Atom = 0x3704
Noembed Atom = 0x4007
Noframes Atom = 0x5508
Nomodule Atom = 0x6108
Nonce Atom = 0x56205
Noscript Atom = 0x1fe08
Novalidate Atom = 0x29a0a
Object Atom = 0x25006
Ol Atom = 0x10102
Onabort Atom = 0x17607
Onafterprint Atom = 0x21e0c
Onautocomplete Atom = 0x25e0e
Onautocompleteerror Atom = 0x25e13
Onauxclick Atom = 0x61b0a
Onbeforeprint Atom = 0x69a0d
Onbeforeunload Atom = 0x6e10e
Onblur Atom = 0x5c206
Oncancel Atom = 0xd308
Oncanplay Atom = 0x13609
Oncanplaythrough Atom = 0x13610
Onchange Atom = 0x40f08
Onclick Atom = 0x2dd07
Onclose Atom = 0x36007
Oncontextmenu Atom = 0x3720d
Oncopy Atom = 0x38506
Oncuechange Atom = 0x38b0b
Oncut Atom = 0x39605
Ondblclick Atom = 0x39b0a
Ondrag Atom = 0x3a506
Ondragend Atom = 0x3a509
Ondragenter Atom = 0x3ae0b
Ondragexit Atom = 0x3b90a
Ondragleave Atom = 0x3d30b
Ondragover Atom = 0x3de0a
Ondragstart Atom = 0x3e80b
Ondrop Atom = 0x3f706
Ondurationchange Atom = 0x40710
Onemptied Atom = 0x3fe09
Onended Atom = 0x41707
Onerror Atom = 0x41e07
Onfocus Atom = 0x42507
Onhashchange Atom = 0x4310c
Oninput Atom = 0x43d07
Oninvalid Atom = 0x44909
Onkeydown Atom = 0x45209
Onkeypress Atom = 0x45f0a
Onkeyup Atom = 0x47407
Onlanguagechange Atom = 0x48110
Onload Atom = 0x49106
Onloadeddata Atom = 0x4910c
Onloadedmetadata Atom = 0x4a410
Onloadend Atom = 0x4ba09
Onloadstart Atom = 0x4c30b
Onmessage Atom = 0x4ce09
Onmessageerror Atom = 0x4ce0e
Onmousedown Atom = 0x4dc0b
Onmouseenter Atom = 0x4e70c
Onmouseleave Atom = 0x4f30c
Onmousemove Atom = 0x4ff0b
Onmouseout Atom = 0x50a0a
Onmouseover Atom = 0x5170b
Onmouseup Atom = 0x52209
Onmousewheel Atom = 0x5300c
Onoffline Atom = 0x53c09
Ononline Atom = 0x54508
Onpagehide Atom = 0x54d0a
Onpageshow Atom = 0x5670a
Onpaste Atom = 0x57307
Onpause Atom = 0x58e07
Onplay Atom = 0x59806
Onplaying Atom = 0x59809
Onpopstate Atom = 0x5a10a
Onprogress Atom = 0x5ab0a
Onratechange Atom = 0x5c80c
Onrejectionhandled Atom = 0x5d412
Onreset Atom = 0x5e607
Onresize Atom = 0x5ed08
Onscroll Atom = 0x5fc08
Onsecuritypolicyviolation Atom = 0x60419
Onseeked Atom = 0x62508
Onseeking Atom = 0x62d09
Onselect Atom = 0x63608
Onshow Atom = 0x64006
Onsort Atom = 0x64b06
Onstalled Atom = 0x65509
Onstorage Atom = 0x65e09
Onsubmit Atom = 0x66708
Onsuspend Atom = 0x67709
Ontimeupdate Atom = 0x11a0c
Ontoggle Atom = 0x68008
Onunhandledrejection Atom = 0x68814
Onunload Atom = 0x6a708
Onvolumechange Atom = 0x6af0e
Onwaiting Atom = 0x6bd09
Onwheel Atom = 0x6c607
Open Atom = 0x55f04
Optgroup Atom = 0xe008
Optimum Atom = 0x6cd07
Option Atom = 0x6dd06
Output Atom = 0x51106
P Atom = 0xc01
Param Atom = 0xc05
Pattern Atom = 0x4f07
Picture Atom = 0x9707
Ping Atom = 0xe704
Placeholder Atom = 0xfb0b
Plaintext Atom = 0x19e09
Playsinline Atom = 0x10a0b
Poster Atom = 0x2b706
Pre Atom = 0x46403
Preload Atom = 0x47a07
Progress Atom = 0x5ad08
Prompt Atom = 0x52a06
Public Atom = 0x57a06
Q Atom = 0x7701
Radiogroup Atom = 0x30a
Readonly Atom = 0x34b08
Referrerpolicy Atom = 0x3c50e
Rel Atom = 0x47b03
Required Atom = 0x23408
Reversed Atom = 0x9c08
Rows Atom = 0x3a04
Rowspan Atom = 0x3a07
Rp Atom = 0x22402
Rt Atom = 0x17b02
Ruby Atom = 0xac04
S Atom = 0x2501
Samp Atom = 0x4c04
Sandbox Atom = 0xf307
Scope Atom = 0x67105
Scoped Atom = 0x67106
Script Atom = 0x20006
Seamless Atom = 0x36508
Section Atom = 0x5bd07
Select Atom = 0x63806
Selected Atom = 0x63808
Shape Atom = 0x1d505
Size Atom = 0x5f104
Sizes Atom = 0x5f105
Slot Atom = 0x1df04
Small Atom = 0x1ee05
Sortable Atom = 0x64d08
Sorted Atom = 0x32b06
Source Atom = 0x36c06
Spacer Atom = 0x42b06
Span Atom = 0x3d04
Spellcheck Atom = 0x4680a
Src Atom = 0x5b403
Srcdoc Atom = 0x5b406
Srclang Atom = 0x5f507
Srcset Atom = 0x6f306
Start Atom = 0x3ee05
Step Atom = 0x57704
Strike Atom = 0x7a06
Strong Atom = 0x31506
Style Atom = 0x6f905
Sub Atom = 0x66903
Summary Atom = 0x6fe07
Sup Atom = 0x70503
Svg Atom = 0x70803
System Atom = 0x70b06
Tabindex Atom = 0x4b208
Table Atom = 0x58905
Target Atom = 0x2ac06
Tbody Atom = 0x2705
Td Atom = 0x5e02
Template Atom = 0x70e08
Textarea Atom = 0x34608
Tfoot Atom = 0xb205
Th Atom = 0x13f02
Thead Atom = 0x32405
Time Atom = 0x11c04
Title Atom = 0xca05
Tr Atom = 0x7402
Track Atom = 0x17c05
Translate Atom = 0x1a609
Tt Atom = 0x5102
Type Atom = 0x8104
Typemustmatch Atom = 0x2780d
U Atom = 0xb01
Ul Atom = 0x6602
Updateviacache Atom = 0x1200e
Usemap Atom = 0x59206
Value Atom = 0x1505
Var Atom = 0x15603
Video Atom = 0x2d905
Wbr Atom = 0x57003
Width Atom = 0x64505
Workertype Atom = 0x7160a
Wrap Atom = 0x72004
Xmp Atom = 0xf903
)
const hash0 = 0x81cdf10e
const maxAtomLen = 25
var table = [1 << 9]Atom{
0x1: 0x8e0a, // mediagroup
0x2: 0x2cc04, // lang
0x4: 0x2c09, // accesskey
0x5: 0x5708, // frameset
0x7: 0x63608, // onselect
0x8: 0x70b06, // system
0xa: 0x64505, // width
0xc: 0x2710b, // formenctype
0xd: 0x10102, // ol
0xe: 0x38b0b, // oncuechange
0x10: 0x13403, // bdo
0x11: 0xcf05, // audio
0x12: 0x18309, // draggable
0x14: 0x2d905, // video
0x15: 0x29902, // mn
0x16: 0x37b04, // menu
0x17: 0x2b706, // poster
0x19: 0xb306, // footer
0x1a: 0x29006, // method
0x1b: 0x2a008, // datetime
0x1c: 0x17607, // onabort
0x1d: 0x1200e, // updateviacache
0x1e: 0xb905, // async
0x1f: 0x49106, // onload
0x21: 0xd308, // oncancel
0x22: 0x62508, // onseeked
0x23: 0x2ea05, // image
0x24: 0x5d412, // onrejectionhandled
0x26: 0x15d04, // link
0x27: 0x51106, // output
0x28: 0x32504, // head
0x29: 0x4f30c, // onmouseleave
0x2a: 0x57307, // onpaste
0x2b: 0x59809, // onplaying
0x2c: 0x1b407, // colspan
0x2f: 0x1af05, // color
0x30: 0x5f104, // size
0x31: 0x2d00a, // http-equiv
0x33: 0x601, // i
0x34: 0x54d0a, // onpagehide
0x35: 0x68814, // onunhandledrejection
0x37: 0x41e07, // onerror
0x3a: 0x11508, // basefont
0x3f: 0x1303, // nav
0x40: 0x18004, // kind
0x41: 0x34b08, // readonly
0x42: 0x2f006, // mglyph
0x44: 0x11102, // li
0x46: 0x2bd06, // hidden
0x47: 0x70803, // svg
0x48: 0x57704, // step
0x49: 0x22709, // integrity
0x4a: 0x57a06, // public
0x4c: 0x19703, // col
0x4d: 0x1680a, // blockquote
0x4e: 0x34302, // h5
0x50: 0x5ad08, // progress
0x51: 0x5f105, // sizes
0x52: 0x33902, // h4
0x56: 0x32405, // thead
0x57: 0x7e07, // keytype
0x58: 0x5ab0a, // onprogress
0x59: 0x43f09, // inputmode
0x5a: 0x3a509, // ondragend
0x5d: 0x39605, // oncut
0x5e: 0x42b06, // spacer
0x5f: 0x19708, // colgroup
0x62: 0x14e02, // is
0x65: 0xb902, // as
0x66: 0x53c09, // onoffline
0x67: 0x32b06, // sorted
0x69: 0x48110, // onlanguagechange
0x6c: 0x4310c, // onhashchange
0x6d: 0xa604, // name
0x6e: 0xb205, // tfoot
0x6f: 0x55504, // desc
0x70: 0x33103, // max
0x72: 0x1da06, // coords
0x73: 0x2f502, // h3
0x74: 0x6e10e, // onbeforeunload
0x75: 0x3a04, // rows
0x76: 0x63806, // select
0x77: 0xa805, // meter
0x78: 0x37f06, // itemid
0x79: 0x5300c, // onmousewheel
0x7a: 0x5b406, // srcdoc
0x7d: 0x17c05, // track
0x7f: 0x30708, // itemtype
0x82: 0x6302, // mo
0x83: 0x40f08, // onchange
0x84: 0x32507, // headers
0x85: 0x5c80c, // onratechange
0x86: 0x60419, // onsecuritypolicyviolation
0x88: 0x49908, // datalist
0x89: 0x4dc0b, // onmousedown
0x8a: 0x1df04, // slot
0x8b: 0x4a410, // onloadedmetadata
0x8c: 0x1a06, // accept
0x8d: 0x25006, // object
0x91: 0x6af0e, // onvolumechange
0x92: 0x2107, // charset
0x93: 0x25e13, // onautocompleteerror
0x94: 0x6913, // allowpaymentrequest
0x95: 0x2804, // body
0x96: 0xc407, // default
0x97: 0x63808, // selected
0x98: 0x20604, // face
0x99: 0x1d505, // shape
0x9b: 0x68008, // ontoggle
0x9e: 0x64702, // dt
0x9f: 0x6d904, // mark
0xa1: 0xb01, // u
0xa4: 0x6a708, // onunload
0xa5: 0xde04, // loop
0xa6: 0x14d08, // disabled
0xaa: 0x41707, // onended
0xab: 0x6d30a, // malignmark
0xad: 0x67709, // onsuspend
0xae: 0x34505, // mtext
0xaf: 0x64b06, // onsort
0xb0: 0x55908, // itemprop
0xb3: 0x66d09, // itemscope
0xb4: 0x15c05, // blink
0xb6: 0x3a506, // ondrag
0xb7: 0x6602, // ul
0xb8: 0x25604, // form
0xb9: 0xf307, // sandbox
0xba: 0x5705, // frame
0xbb: 0x1505, // value
0xbc: 0x65e09, // onstorage
0xc0: 0x17b02, // rt
0xc2: 0x202, // br
0xc3: 0x20e08, // fieldset
0xc4: 0x2780d, // typemustmatch
0xc5: 0x6108, // nomodule
0xc6: 0x4007, // noembed
0xc7: 0x69a0d, // onbeforeprint
0xc8: 0x17206, // button
0xc9: 0x2dd07, // onclick
0xca: 0x6fe07, // summary
0xcd: 0xac04, // ruby
0xce: 0x5b905, // class
0xcf: 0x3e80b, // ondragstart
0xd0: 0x21907, // caption
0xd4: 0x850e, // allowusermedia
0xd5: 0x4c30b, // onloadstart
0xd9: 0x15403, // div
0xda: 0x49d04, // list
0xdb: 0x32204, // math
0xdc: 0x43f05, // input
0xdf: 0x3de0a, // ondragover
0xe0: 0x2c602, // h2
0xe2: 0x19e09, // plaintext
0xe4: 0x4e70c, // onmouseenter
0xe7: 0x46d07, // checked
0xe8: 0x46403, // pre
0xea: 0x35308, // multiple
0xeb: 0x16103, // bdi
0xec: 0x33109, // maxlength
0xed: 0x7701, // q
0xee: 0x61b0a, // onauxclick
0xf0: 0x57003, // wbr
0xf2: 0x11504, // base
0xf3: 0x6dd06, // option
0xf5: 0x40710, // ondurationchange
0xf7: 0x5508, // noframes
0xf9: 0x3f908, // dropzone
0xfb: 0x67105, // scope
0xfc: 0x9c08, // reversed
0xfd: 0x3ae0b, // ondragenter
0xfe: 0x3ee05, // start
0xff: 0xf903, // xmp
0x100: 0x5f507, // srclang
0x101: 0x2ef03, // img
0x104: 0x101, // b
0x105: 0x23c03, // for
0x106: 0xc105, // aside
0x107: 0x43d07, // oninput
0x108: 0x34a04, // area
0x109: 0x28c0a, // formmethod
0x10a: 0x72004, // wrap
0x10c: 0x22402, // rp
0x10d: 0x45f0a, // onkeypress
0x10e: 0x5102, // tt
0x110: 0x33b02, // mi
0x111: 0x35b05, // muted
0x112: 0xb003, // alt
0x113: 0x19004, // code
0x114: 0x4202, // em
0x115: 0x3b90a, // ondragexit
0x117: 0x3d04, // span
0x119: 0x30f08, // manifest
0x11a: 0x37b08, // menuitem
0x11b: 0x57f07, // content
0x11d: 0x6bd09, // onwaiting
0x11f: 0x4ba09, // onloadend
0x121: 0x3720d, // oncontextmenu
0x123: 0x5c206, // onblur
0x124: 0x3f007, // article
0x125: 0xa303, // dir
0x126: 0xe704, // ping
0x127: 0x23408, // required
0x128: 0x44909, // oninvalid
0x129: 0x6d405, // align
0x12b: 0x57e04, // icon
0x12c: 0x64902, // h6
0x12d: 0x1b404, // cols
0x12e: 0x2160a, // figcaption
0x12f: 0x45209, // onkeydown
0x130: 0x66708, // onsubmit
0x131: 0x13609, // oncanplay
0x132: 0x70503, // sup
0x133: 0xc01, // p
0x135: 0x3fe09, // onemptied
0x136: 0x38506, // oncopy
0x137: 0x55804, // cite
0x138: 0x39b0a, // ondblclick
0x13a: 0x4ff0b, // onmousemove
0x13c: 0x66903, // sub
0x13d: 0x47b03, // rel
0x13e: 0xe008, // optgroup
0x142: 0x3a07, // rowspan
0x143: 0x36c06, // source
0x144: 0x1fe08, // noscript
0x145: 0x55f04, // open
0x146: 0x1ec03, // ins
0x147: 0x23c0d, // foreignObject
0x148: 0x5a10a, // onpopstate
0x14a: 0x27507, // enctype
0x14b: 0x25e0e, // onautocomplete
0x14c: 0x34608, // textarea
0x14e: 0x2600c, // autocomplete
0x14f: 0x14002, // hr
0x150: 0x1ce08, // controls
0x151: 0xc302, // id
0x153: 0x21e0c, // onafterprint
0x155: 0x2490d, // foreignobject
0x156: 0x31b07, // marquee
0x157: 0x58e07, // onpause
0x158: 0x5e202, // dl
0x159: 0x12c06, // height
0x15a: 0x33b03, // min
0x15b: 0xa307, // dirname
0x15c: 0x1a609, // translate
0x15d: 0x13004, // html
0x15e: 0x33b09, // minlength
0x15f: 0x47a07, // preload
0x160: 0x70e08, // template
0x161: 0x3d30b, // ondragleave
0x164: 0x5b403, // src
0x165: 0x31506, // strong
0x167: 0x4c04, // samp
0x168: 0x6ed07, // address
0x169: 0x54508, // ononline
0x16b: 0xfb0b, // placeholder
0x16c: 0x2ac06, // target
0x16d: 0x1ee05, // small
0x16e: 0x6c607, // onwheel
0x16f: 0x1b90a, // annotation
0x170: 0x4680a, // spellcheck
0x171: 0x4607, // details
0x172: 0xbd06, // canvas
0x173: 0xeb09, // autofocus
0x174: 0xc05, // param
0x176: 0x45708, // download
0x177: 0x44603, // del
0x178: 0x36007, // onclose
0x179: 0x16003, // kbd
0x17a: 0x30106, // applet
0x17b: 0x2c804, // href
0x17c: 0x5ed08, // onresize
0x17e: 0x4910c, // onloadeddata
0x180: 0x7402, // tr
0x181: 0x2a80a, // formtarget
0x182: 0xca05, // title
0x183: 0x6f905, // style
0x184: 0x7a06, // strike
0x185: 0x59206, // usemap
0x186: 0x2e406, // iframe
0x187: 0x1004, // main
0x189: 0x9707, // picture
0x18c: 0x2fe05, // ismap
0x18e: 0x49904, // data
0x18f: 0xda05, // label
0x191: 0x3c50e, // referrerpolicy
0x192: 0x13f02, // th
0x194: 0x52a06, // prompt
0x195: 0x5bd07, // section
0x197: 0x6cd07, // optimum
0x198: 0x2c304, // high
0x199: 0x14502, // h1
0x19a: 0x65509, // onstalled
0x19b: 0x15603, // var
0x19c: 0x11c04, // time
0x19e: 0x67002, // ms
0x19f: 0x32506, // header
0x1a0: 0x4ce09, // onmessage
0x1a1: 0x56205, // nonce
0x1a2: 0x2560a, // formaction
0x1a3: 0x20806, // center
0x1a4: 0x3704, // nobr
0x1a5: 0x58905, // table
0x1a6: 0x49d07, // listing
0x1a7: 0x18a06, // legend
0x1a9: 0x28309, // challenge
0x1aa: 0x23006, // figure
0x1ab: 0x8e05, // media
0x1ae: 0x8104, // type
0x1af: 0x11904, // font
0x1b0: 0x4ce0e, // onmessageerror
0x1b1: 0x36508, // seamless
0x1b2: 0x5f03, // dfn
0x1b3: 0x19205, // defer
0x1b4: 0x6b03, // low
0x1b5: 0x62d09, // onseeking
0x1b6: 0x5170b, // onmouseover
0x1b7: 0x29a0a, // novalidate
0x1b8: 0x7160a, // workertype
0x1ba: 0x3c107, // itemref
0x1bd: 0x1, // a
0x1be: 0x30003, // map
0x1bf: 0x11a0c, // ontimeupdate
0x1c0: 0x14707, // bgsound
0x1c1: 0x3206, // keygen
0x1c2: 0x2705, // tbody
0x1c5: 0x64006, // onshow
0x1c7: 0x2501, // s
0x1c8: 0x4f07, // pattern
0x1cc: 0x13610, // oncanplaythrough
0x1ce: 0x2bf02, // dd
0x1cf: 0x6f306, // srcset
0x1d0: 0x15903, // big
0x1d2: 0x64d08, // sortable
0x1d3: 0x47407, // onkeyup
0x1d5: 0x59806, // onplay
0x1d7: 0x4ac04, // meta
0x1d8: 0x3f706, // ondrop
0x1da: 0x5fc08, // onscroll
0x1db: 0x1e30b, // crossorigin
0x1dc: 0x5670a, // onpageshow
0x1dd: 0x4, // abbr
0x1de: 0x5e02, // td
0x1df: 0x57f0f, // contenteditable
0x1e0: 0x25a06, // action
0x1e1: 0x10a0b, // playsinline
0x1e2: 0x42507, // onfocus
0x1e3: 0x2c808, // hreflang
0x1e5: 0x50a0a, // onmouseout
0x1e6: 0x5e607, // onreset
0x1e7: 0x10608, // autoplay
0x1ea: 0x67106, // scoped
0x1ec: 0x30a, // radiogroup
0x1ee: 0x3740b, // contextmenu
0x1ef: 0x52209, // onmouseup
0x1f1: 0x2b206, // hgroup
0x1f2: 0x1f00f, // allowfullscreen
0x1f3: 0x4b208, // tabindex
0x1f6: 0x2f707, // isindex
0x1f7: 0x1a0e, // accept-charset
0x1f8: 0x2960e, // formnovalidate
0x1fb: 0x1b90e, // annotation-xml
0x1fc: 0x4205, // embed
0x1fd: 0x20006, // script
0x1fe: 0x16206, // dialog
0x1ff: 0x1c707, // command
}
const atomText = "abbradiogrouparamainavalueaccept-charsetbodyaccesskeygenobro" +
"wspanoembedetailsampatternoframesetdfnomoduleallowpaymentreq" +
"uestrikeytypeallowusermediagroupictureversedirnameterubyaltf" +
"ooterasyncanvasidefaultitleaudioncancelabelooptgroupingautof" +
"ocusandboxmplaceholderautoplaysinlinebasefontimeupdateviacac" +
"heightmlbdoncanplaythrough1bgsoundisabledivarbigblinkbdialog" +
"blockquotebuttonabortrackindraggablegendcodefercolgrouplaint" +
"extranslatecolorcolspannotation-xmlcommandcontrolshapecoords" +
"lotcrossoriginsmallowfullscreenoscriptfacenterfieldsetfigcap" +
"tionafterprintegrityfigurequiredforeignObjectforeignobjectfo" +
"rmactionautocompleteerrorformenctypemustmatchallengeformmeth" +
"odformnovalidatetimeformtargethgrouposterhiddenhigh2hreflang" +
"http-equivideonclickiframeimageimglyph3isindexismappletitemt" +
"ypemanifestrongmarqueematheadersortedmaxlength4minlength5mte" +
"xtareadonlymultiplemutedoncloseamlessourceoncontextmenuitemi" +
"doncopyoncuechangeoncutondblclickondragendondragenterondrage" +
"xitemreferrerpolicyondragleaveondragoverondragstarticleondro" +
"pzonemptiedondurationchangeonendedonerroronfocuspaceronhashc" +
"hangeoninputmodeloninvalidonkeydownloadonkeypresspellchecked" +
"onkeyupreloadonlanguagechangeonloadeddatalistingonloadedmeta" +
"databindexonloadendonloadstartonmessageerroronmousedownonmou" +
"seenteronmouseleaveonmousemoveonmouseoutputonmouseoveronmous" +
"eupromptonmousewheelonofflineononlineonpagehidescitempropeno" +
"nceonpageshowbronpastepublicontenteditableonpausemaponplayin" +
"gonpopstateonprogressrcdoclassectionbluronratechangeonreject" +
"ionhandledonresetonresizesrclangonscrollonsecuritypolicyviol" +
"ationauxclickonseekedonseekingonselectedonshowidth6onsortabl" +
"eonstalledonstorageonsubmitemscopedonsuspendontoggleonunhand" +
"ledrejectionbeforeprintonunloadonvolumechangeonwaitingonwhee" +
"loptimumalignmarkoptionbeforeunloaddressrcsetstylesummarysup" +
"svgsystemplateworkertypewrap"
+104
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
// Section 12.2.3.2 of the HTML5 specification says "The following elements
// have varying levels of special parsing rules".
// https://html.spec.whatwg.org/multipage/syntax.html#the-stack-of-open-elements
var isSpecialElementMap = map[string]bool{
"address": true,
"applet": true,
"area": true,
"article": true,
"aside": true,
"base": true,
"basefont": true,
"bgsound": true,
"blockquote": true,
"body": true,
"br": true,
"button": true,
"caption": true,
"center": true,
"col": true,
"colgroup": true,
"dd": true,
"details": true,
"dir": true,
"div": true,
"dl": true,
"dt": true,
"embed": true,
"fieldset": true,
"figcaption": true,
"figure": true,
"footer": true,
"form": true,
"frame": true,
"frameset": true,
"h1": true,
"h2": true,
"h3": true,
"h4": true,
"h5": true,
"h6": true,
"head": true,
"header": true,
"hgroup": true,
"hr": true,
"html": true,
"iframe": true,
"img": true,
"input": true,
"isindex": true, // The 'isindex' element has been removed, but keep it for backwards compatibility.
"keygen": true,
"li": true,
"link": true,
"listing": true,
"main": true,
"marquee": true,
"menu": true,
"meta": true,
"nav": true,
"noembed": true,
"noframes": true,
"noscript": true,
"object": true,
"ol": true,
"p": true,
"param": true,
"plaintext": true,
"pre": true,
"script": true,
"section": true,
"select": true,
"source": true,
"style": true,
"summary": true,
"table": true,
"tbody": true,
"td": true,
"template": true,
"textarea": true,
"tfoot": true,
"th": true,
"thead": true,
"title": true,
"tr": true,
"track": true,
"ul": true,
"wbr": true,
"xmp": true,
}
func isSpecialElement(element *Node) bool {
switch element.Namespace {
case "", "html":
return isSpecialElementMap[element.Data]
case "svg":
return element.Data == "foreignObject"
}
return false
}
+106
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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
/*
Package html implements an HTML5-compliant tokenizer and parser.
Tokenization is done by creating a Tokenizer for an io.Reader r. It is the
caller's responsibility to ensure that r provides UTF-8 encoded HTML.
z := html.NewTokenizer(r)
Given a Tokenizer z, the HTML is tokenized by repeatedly calling z.Next(),
which parses the next token and returns its type, or an error:
for {
tt := z.Next()
if tt == html.ErrorToken {
// ...
return ...
}
// Process the current token.
}
There are two APIs for retrieving the current token. The high-level API is to
call Token; the low-level API is to call Text or TagName / TagAttr. Both APIs
allow optionally calling Raw after Next but before Token, Text, TagName, or
TagAttr. In EBNF notation, the valid call sequence per token is:
Next {Raw} [ Token | Text | TagName {TagAttr} ]
Token returns an independent data structure that completely describes a token.
Entities (such as "&lt;") are unescaped, tag names and attribute keys are
lower-cased, and attributes are collected into a []Attribute. For example:
for {
if z.Next() == html.ErrorToken {
// Returning io.EOF indicates success.
return z.Err()
}
emitToken(z.Token())
}
The low-level API performs fewer allocations and copies, but the contents of
the []byte values returned by Text, TagName and TagAttr may change on the next
call to Next. For example, to extract an HTML page's anchor text:
depth := 0
for {
tt := z.Next()
switch tt {
case html.ErrorToken:
return z.Err()
case html.TextToken:
if depth > 0 {
// emitBytes should copy the []byte it receives,
// if it doesn't process it immediately.
emitBytes(z.Text())
}
case html.StartTagToken, html.EndTagToken:
tn, _ := z.TagName()
if len(tn) == 1 && tn[0] == 'a' {
if tt == html.StartTagToken {
depth++
} else {
depth--
}
}
}
}
Parsing is done by calling Parse with an io.Reader, which returns the root of
the parse tree (the document element) as a *Node. It is the caller's
responsibility to ensure that the Reader provides UTF-8 encoded HTML. For
example, to process each anchor node in depth-first order:
doc, err := html.Parse(r)
if err != nil {
// ...
}
var f func(*html.Node)
f = func(n *html.Node) {
if n.Type == html.ElementNode && n.Data == "a" {
// Do something with n...
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
f(c)
}
}
f(doc)
The relevant specifications include:
https://html.spec.whatwg.org/multipage/syntax.html and
https://html.spec.whatwg.org/multipage/syntax.html#tokenization
*/
package html // import "golang.org/x/net/html"
// The tokenization algorithm implemented by this package is not a line-by-line
// transliteration of the relatively verbose state-machine in the WHATWG
// specification. A more direct approach is used instead, where the program
// counter implies the state, such as whether it is tokenizing a tag or a text
// node. Specification compliance is verified by checking expected and actual
// outputs over a test suite rather than aiming for algorithmic fidelity.
// TODO(nigeltao): Does a DOM API belong in this package or a separate one?
// TODO(nigeltao): How does parsing interact with a JavaScript engine?
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
import (
"strings"
)
// parseDoctype parses the data from a DoctypeToken into a name,
// public identifier, and system identifier. It returns a Node whose Type
// is DoctypeNode, whose Data is the name, and which has attributes
// named "system" and "public" for the two identifiers if they were present.
// quirks is whether the document should be parsed in "quirks mode".
func parseDoctype(s string) (n *Node, quirks bool) {
n = &Node{Type: DoctypeNode}
// Find the name.
space := strings.IndexAny(s, whitespace)
if space == -1 {
space = len(s)
}
n.Data = s[:space]
// The comparison to "html" is case-sensitive.
if n.Data != "html" {
quirks = true
}
n.Data = strings.ToLower(n.Data)
s = strings.TrimLeft(s[space:], whitespace)
if len(s) < 6 {
// It can't start with "PUBLIC" or "SYSTEM".
// Ignore the rest of the string.
return n, quirks || s != ""
}
key := strings.ToLower(s[:6])
s = s[6:]
for key == "public" || key == "system" {
s = strings.TrimLeft(s, whitespace)
if s == "" {
break
}
quote := s[0]
if quote != '"' && quote != '\'' {
break
}
s = s[1:]
q := strings.IndexRune(s, rune(quote))
var id string
if q == -1 {
id = s
s = ""
} else {
id = s[:q]
s = s[q+1:]
}
n.Attr = append(n.Attr, Attribute{Key: key, Val: id})
if key == "public" {
key = "system"
} else {
key = ""
}
}
if key != "" || s != "" {
quirks = true
} else if len(n.Attr) > 0 {
if n.Attr[0].Key == "public" {
public := strings.ToLower(n.Attr[0].Val)
switch public {
case "-//w3o//dtd w3 html strict 3.0//en//", "-/w3d/dtd html 4.0 transitional/en", "html":
quirks = true
default:
for _, q := range quirkyIDs {
if strings.HasPrefix(public, q) {
quirks = true
break
}
}
}
// The following two public IDs only cause quirks mode if there is no system ID.
if len(n.Attr) == 1 && (strings.HasPrefix(public, "-//w3c//dtd html 4.01 frameset//") ||
strings.HasPrefix(public, "-//w3c//dtd html 4.01 transitional//")) {
quirks = true
}
}
if lastAttr := n.Attr[len(n.Attr)-1]; lastAttr.Key == "system" &&
strings.ToLower(lastAttr.Val) == "http://www.ibm.com/data/dtd/v11/ibmxhtml1-transitional.dtd" {
quirks = true
}
}
return n, quirks
}
// quirkyIDs is a list of public doctype identifiers that cause a document
// to be interpreted in quirks mode. The identifiers should be in lower case.
var quirkyIDs = []string{
"+//silmaril//dtd html pro v0r11 19970101//",
"-//advasoft ltd//dtd html 3.0 aswedit + extensions//",
"-//as//dtd html 3.0 aswedit + extensions//",
"-//ietf//dtd html 2.0 level 1//",
"-//ietf//dtd html 2.0 level 2//",
"-//ietf//dtd html 2.0 strict level 1//",
"-//ietf//dtd html 2.0 strict level 2//",
"-//ietf//dtd html 2.0 strict//",
"-//ietf//dtd html 2.0//",
"-//ietf//dtd html 2.1e//",
"-//ietf//dtd html 3.0//",
"-//ietf//dtd html 3.2 final//",
"-//ietf//dtd html 3.2//",
"-//ietf//dtd html 3//",
"-//ietf//dtd html level 0//",
"-//ietf//dtd html level 1//",
"-//ietf//dtd html level 2//",
"-//ietf//dtd html level 3//",
"-//ietf//dtd html strict level 0//",
"-//ietf//dtd html strict level 1//",
"-//ietf//dtd html strict level 2//",
"-//ietf//dtd html strict level 3//",
"-//ietf//dtd html strict//",
"-//ietf//dtd html//",
"-//metrius//dtd metrius presentational//",
"-//microsoft//dtd internet explorer 2.0 html strict//",
"-//microsoft//dtd internet explorer 2.0 html//",
"-//microsoft//dtd internet explorer 2.0 tables//",
"-//microsoft//dtd internet explorer 3.0 html strict//",
"-//microsoft//dtd internet explorer 3.0 html//",
"-//microsoft//dtd internet explorer 3.0 tables//",
"-//netscape comm. corp.//dtd html//",
"-//netscape comm. corp.//dtd strict html//",
"-//o'reilly and associates//dtd html 2.0//",
"-//o'reilly and associates//dtd html extended 1.0//",
"-//o'reilly and associates//dtd html extended relaxed 1.0//",
"-//softquad software//dtd hotmetal pro 6.0::19990601::extensions to html 4.0//",
"-//softquad//dtd hotmetal pro 4.0::19971010::extensions to html 4.0//",
"-//spyglass//dtd html 2.0 extended//",
"-//sq//dtd html 2.0 hotmetal + extensions//",
"-//sun microsystems corp.//dtd hotjava html//",
"-//sun microsystems corp.//dtd hotjava strict html//",
"-//w3c//dtd html 3 1995-03-24//",
"-//w3c//dtd html 3.2 draft//",
"-//w3c//dtd html 3.2 final//",
"-//w3c//dtd html 3.2//",
"-//w3c//dtd html 3.2s draft//",
"-//w3c//dtd html 4.0 frameset//",
"-//w3c//dtd html 4.0 transitional//",
"-//w3c//dtd html experimental 19960712//",
"-//w3c//dtd html experimental 970421//",
"-//w3c//dtd w3 html//",
"-//w3o//dtd w3 html 3.0//",
"-//webtechs//dtd mozilla html 2.0//",
"-//webtechs//dtd mozilla html//",
}
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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
import (
"bytes"
"strings"
"unicode/utf8"
)
// These replacements permit compatibility with old numeric entities that
// assumed Windows-1252 encoding.
// https://html.spec.whatwg.org/multipage/syntax.html#consume-a-character-reference
var replacementTable = [...]rune{
'\u20AC', // First entry is what 0x80 should be replaced with.
'\u0081',
'\u201A',
'\u0192',
'\u201E',
'\u2026',
'\u2020',
'\u2021',
'\u02C6',
'\u2030',
'\u0160',
'\u2039',
'\u0152',
'\u008D',
'\u017D',
'\u008F',
'\u0090',
'\u2018',
'\u2019',
'\u201C',
'\u201D',
'\u2022',
'\u2013',
'\u2014',
'\u02DC',
'\u2122',
'\u0161',
'\u203A',
'\u0153',
'\u009D',
'\u017E',
'\u0178', // Last entry is 0x9F.
// 0x00->'\uFFFD' is handled programmatically.
// 0x0D->'\u000D' is a no-op.
}
// unescapeEntity reads an entity like "&lt;" from b[src:] and writes the
// corresponding "<" to b[dst:], returning the incremented dst and src cursors.
// Precondition: b[src] == '&' && dst <= src.
// attribute should be true if parsing an attribute value.
func unescapeEntity(b []byte, dst, src int, attribute bool) (dst1, src1 int) {
// https://html.spec.whatwg.org/multipage/syntax.html#consume-a-character-reference
// i starts at 1 because we already know that s[0] == '&'.
i, s := 1, b[src:]
if len(s) <= 1 {
b[dst] = b[src]
return dst + 1, src + 1
}
if s[i] == '#' {
if len(s) <= 3 { // We need to have at least "&#.".
b[dst] = b[src]
return dst + 1, src + 1
}
i++
c := s[i]
hex := false
if c == 'x' || c == 'X' {
hex = true
i++
}
x := '\x00'
for i < len(s) {
c = s[i]
i++
if hex {
if '0' <= c && c <= '9' {
x = 16*x + rune(c) - '0'
continue
} else if 'a' <= c && c <= 'f' {
x = 16*x + rune(c) - 'a' + 10
continue
} else if 'A' <= c && c <= 'F' {
x = 16*x + rune(c) - 'A' + 10
continue
}
} else if '0' <= c && c <= '9' {
x = 10*x + rune(c) - '0'
continue
}
if c != ';' {
i--
}
break
}
if i <= 3 { // No characters matched.
b[dst] = b[src]
return dst + 1, src + 1
}
if 0x80 <= x && x <= 0x9F {
// Replace characters from Windows-1252 with UTF-8 equivalents.
x = replacementTable[x-0x80]
} else if x == 0 || (0xD800 <= x && x <= 0xDFFF) || x > 0x10FFFF {
// Replace invalid characters with the replacement character.
x = '\uFFFD'
}
return dst + utf8.EncodeRune(b[dst:], x), src + i
}
// Consume the maximum number of characters possible, with the
// consumed characters matching one of the named references.
for i < len(s) {
c := s[i]
i++
// Lower-cased characters are more common in entities, so we check for them first.
if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || '0' <= c && c <= '9' {
continue
}
if c != ';' {
i--
}
break
}
entityName := string(s[1:i])
if entityName == "" {
// No-op.
} else if attribute && entityName[len(entityName)-1] != ';' && len(s) > i && s[i] == '=' {
// No-op.
} else if x := entity[entityName]; x != 0 {
return dst + utf8.EncodeRune(b[dst:], x), src + i
} else if x := entity2[entityName]; x[0] != 0 {
dst1 := dst + utf8.EncodeRune(b[dst:], x[0])
return dst1 + utf8.EncodeRune(b[dst1:], x[1]), src + i
} else if !attribute {
maxLen := len(entityName) - 1
if maxLen > longestEntityWithoutSemicolon {
maxLen = longestEntityWithoutSemicolon
}
for j := maxLen; j > 1; j-- {
if x := entity[entityName[:j]]; x != 0 {
return dst + utf8.EncodeRune(b[dst:], x), src + j + 1
}
}
}
dst1, src1 = dst+i, src+i
copy(b[dst:dst1], b[src:src1])
return dst1, src1
}
// unescape unescapes b's entities in-place, so that "a&lt;b" becomes "a<b".
// attribute should be true if parsing an attribute value.
func unescape(b []byte, attribute bool) []byte {
for i, c := range b {
if c == '&' {
dst, src := unescapeEntity(b, i, i, attribute)
for src < len(b) {
c := b[src]
if c == '&' {
dst, src = unescapeEntity(b, dst, src, attribute)
} else {
b[dst] = c
dst, src = dst+1, src+1
}
}
return b[0:dst]
}
}
return b
}
// lower lower-cases the A-Z bytes in b in-place, so that "aBc" becomes "abc".
func lower(b []byte) []byte {
for i, c := range b {
if 'A' <= c && c <= 'Z' {
b[i] = c + 'a' - 'A'
}
}
return b
}
const escapedChars = "&'<>\"\r"
func escape(w writer, s string) error {
i := strings.IndexAny(s, escapedChars)
for i != -1 {
if _, err := w.WriteString(s[:i]); err != nil {
return err
}
var esc string
switch s[i] {
case '&':
esc = "&amp;"
case '\'':
// "&#39;" is shorter than "&apos;" and apos was not in HTML until HTML5.
esc = "&#39;"
case '<':
esc = "&lt;"
case '>':
esc = "&gt;"
case '"':
// "&#34;" is shorter than "&quot;".
esc = "&#34;"
case '\r':
esc = "&#13;"
default:
panic("unrecognized escape character")
}
s = s[i+1:]
if _, err := w.WriteString(esc); err != nil {
return err
}
i = strings.IndexAny(s, escapedChars)
}
_, err := w.WriteString(s)
return err
}
// EscapeString escapes special characters like "<" to become "&lt;". It
// escapes only five such characters: <, >, &, ' and ".
// UnescapeString(EscapeString(s)) == s always holds, but the converse isn't
// always true.
func EscapeString(s string) string {
if strings.IndexAny(s, escapedChars) == -1 {
return s
}
var buf bytes.Buffer
escape(&buf, s)
return buf.String()
}
// UnescapeString unescapes entities like "&lt;" to become "<". It unescapes a
// larger range of entities than EscapeString escapes. For example, "&aacute;"
// unescapes to "á", as does "&#225;" and "&xE1;".
// UnescapeString(EscapeString(s)) == s always holds, but the converse isn't
// always true.
func UnescapeString(s string) string {
for _, c := range s {
if c == '&' {
return string(unescape([]byte(s), false))
}
}
return s
}
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
import (
"strings"
)
func adjustAttributeNames(aa []Attribute, nameMap map[string]string) {
for i := range aa {
if newName, ok := nameMap[aa[i].Key]; ok {
aa[i].Key = newName
}
}
}
func adjustForeignAttributes(aa []Attribute) {
for i, a := range aa {
if a.Key == "" || a.Key[0] != 'x' {
continue
}
switch a.Key {
case "xlink:actuate", "xlink:arcrole", "xlink:href", "xlink:role", "xlink:show",
"xlink:title", "xlink:type", "xml:base", "xml:lang", "xml:space", "xmlns:xlink":
j := strings.Index(a.Key, ":")
aa[i].Namespace = a.Key[:j]
aa[i].Key = a.Key[j+1:]
}
}
}
func htmlIntegrationPoint(n *Node) bool {
if n.Type != ElementNode {
return false
}
switch n.Namespace {
case "math":
if n.Data == "annotation-xml" {
for _, a := range n.Attr {
if a.Key == "encoding" {
val := strings.ToLower(a.Val)
if val == "text/html" || val == "application/xhtml+xml" {
return true
}
}
}
}
case "svg":
switch n.Data {
case "desc", "foreignObject", "title":
return true
}
}
return false
}
func mathMLTextIntegrationPoint(n *Node) bool {
if n.Namespace != "math" {
return false
}
switch n.Data {
case "mi", "mo", "mn", "ms", "mtext":
return true
}
return false
}
// Section 12.2.5.5.
var breakout = map[string]bool{
"b": true,
"big": true,
"blockquote": true,
"body": true,
"br": true,
"center": true,
"code": true,
"dd": true,
"div": true,
"dl": true,
"dt": true,
"em": true,
"embed": true,
"h1": true,
"h2": true,
"h3": true,
"h4": true,
"h5": true,
"h6": true,
"head": true,
"hr": true,
"i": true,
"img": true,
"li": true,
"listing": true,
"menu": true,
"meta": true,
"nobr": true,
"ol": true,
"p": true,
"pre": true,
"ruby": true,
"s": true,
"small": true,
"span": true,
"strong": true,
"strike": true,
"sub": true,
"sup": true,
"table": true,
"tt": true,
"u": true,
"ul": true,
"var": true,
}
// Section 12.2.5.5.
var svgTagNameAdjustments = map[string]string{
"altglyph": "altGlyph",
"altglyphdef": "altGlyphDef",
"altglyphitem": "altGlyphItem",
"animatecolor": "animateColor",
"animatemotion": "animateMotion",
"animatetransform": "animateTransform",
"clippath": "clipPath",
"feblend": "feBlend",
"fecolormatrix": "feColorMatrix",
"fecomponenttransfer": "feComponentTransfer",
"fecomposite": "feComposite",
"feconvolvematrix": "feConvolveMatrix",
"fediffuselighting": "feDiffuseLighting",
"fedisplacementmap": "feDisplacementMap",
"fedistantlight": "feDistantLight",
"feflood": "feFlood",
"fefunca": "feFuncA",
"fefuncb": "feFuncB",
"fefuncg": "feFuncG",
"fefuncr": "feFuncR",
"fegaussianblur": "feGaussianBlur",
"feimage": "feImage",
"femerge": "feMerge",
"femergenode": "feMergeNode",
"femorphology": "feMorphology",
"feoffset": "feOffset",
"fepointlight": "fePointLight",
"fespecularlighting": "feSpecularLighting",
"fespotlight": "feSpotLight",
"fetile": "feTile",
"feturbulence": "feTurbulence",
"foreignobject": "foreignObject",
"glyphref": "glyphRef",
"lineargradient": "linearGradient",
"radialgradient": "radialGradient",
"textpath": "textPath",
}
// Section 12.2.5.1
var mathMLAttributeAdjustments = map[string]string{
"definitionurl": "definitionURL",
}
var svgAttributeAdjustments = map[string]string{
"attributename": "attributeName",
"attributetype": "attributeType",
"basefrequency": "baseFrequency",
"baseprofile": "baseProfile",
"calcmode": "calcMode",
"clippathunits": "clipPathUnits",
"contentscripttype": "contentScriptType",
"contentstyletype": "contentStyleType",
"diffuseconstant": "diffuseConstant",
"edgemode": "edgeMode",
"externalresourcesrequired": "externalResourcesRequired",
"filterres": "filterRes",
"filterunits": "filterUnits",
"glyphref": "glyphRef",
"gradienttransform": "gradientTransform",
"gradientunits": "gradientUnits",
"kernelmatrix": "kernelMatrix",
"kernelunitlength": "kernelUnitLength",
"keypoints": "keyPoints",
"keysplines": "keySplines",
"keytimes": "keyTimes",
"lengthadjust": "lengthAdjust",
"limitingconeangle": "limitingConeAngle",
"markerheight": "markerHeight",
"markerunits": "markerUnits",
"markerwidth": "markerWidth",
"maskcontentunits": "maskContentUnits",
"maskunits": "maskUnits",
"numoctaves": "numOctaves",
"pathlength": "pathLength",
"patterncontentunits": "patternContentUnits",
"patterntransform": "patternTransform",
"patternunits": "patternUnits",
"pointsatx": "pointsAtX",
"pointsaty": "pointsAtY",
"pointsatz": "pointsAtZ",
"preservealpha": "preserveAlpha",
"preserveaspectratio": "preserveAspectRatio",
"primitiveunits": "primitiveUnits",
"refx": "refX",
"refy": "refY",
"repeatcount": "repeatCount",
"repeatdur": "repeatDur",
"requiredextensions": "requiredExtensions",
"requiredfeatures": "requiredFeatures",
"specularconstant": "specularConstant",
"specularexponent": "specularExponent",
"spreadmethod": "spreadMethod",
"startoffset": "startOffset",
"stddeviation": "stdDeviation",
"stitchtiles": "stitchTiles",
"surfacescale": "surfaceScale",
"systemlanguage": "systemLanguage",
"tablevalues": "tableValues",
"targetx": "targetX",
"targety": "targetY",
"textlength": "textLength",
"viewbox": "viewBox",
"viewtarget": "viewTarget",
"xchannelselector": "xChannelSelector",
"ychannelselector": "yChannelSelector",
"zoomandpan": "zoomAndPan",
}
+193
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@@ -0,0 +1,193 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
import (
"golang.org/x/net/html/atom"
)
// A NodeType is the type of a Node.
type NodeType uint32
const (
ErrorNode NodeType = iota
TextNode
DocumentNode
ElementNode
CommentNode
DoctypeNode
scopeMarkerNode
)
// Section 12.2.3.3 says "scope markers are inserted when entering applet
// elements, buttons, object elements, marquees, table cells, and table
// captions, and are used to prevent formatting from 'leaking'".
var scopeMarker = Node{Type: scopeMarkerNode}
// A Node consists of a NodeType and some Data (tag name for element nodes,
// content for text) and are part of a tree of Nodes. Element nodes may also
// have a Namespace and contain a slice of Attributes. Data is unescaped, so
// that it looks like "a<b" rather than "a&lt;b". For element nodes, DataAtom
// is the atom for Data, or zero if Data is not a known tag name.
//
// An empty Namespace implies a "http://www.w3.org/1999/xhtml" namespace.
// Similarly, "math" is short for "http://www.w3.org/1998/Math/MathML", and
// "svg" is short for "http://www.w3.org/2000/svg".
type Node struct {
Parent, FirstChild, LastChild, PrevSibling, NextSibling *Node
Type NodeType
DataAtom atom.Atom
Data string
Namespace string
Attr []Attribute
}
// InsertBefore inserts newChild as a child of n, immediately before oldChild
// in the sequence of n's children. oldChild may be nil, in which case newChild
// is appended to the end of n's children.
//
// It will panic if newChild already has a parent or siblings.
func (n *Node) InsertBefore(newChild, oldChild *Node) {
if newChild.Parent != nil || newChild.PrevSibling != nil || newChild.NextSibling != nil {
panic("html: InsertBefore called for an attached child Node")
}
var prev, next *Node
if oldChild != nil {
prev, next = oldChild.PrevSibling, oldChild
} else {
prev = n.LastChild
}
if prev != nil {
prev.NextSibling = newChild
} else {
n.FirstChild = newChild
}
if next != nil {
next.PrevSibling = newChild
} else {
n.LastChild = newChild
}
newChild.Parent = n
newChild.PrevSibling = prev
newChild.NextSibling = next
}
// AppendChild adds a node c as a child of n.
//
// It will panic if c already has a parent or siblings.
func (n *Node) AppendChild(c *Node) {
if c.Parent != nil || c.PrevSibling != nil || c.NextSibling != nil {
panic("html: AppendChild called for an attached child Node")
}
last := n.LastChild
if last != nil {
last.NextSibling = c
} else {
n.FirstChild = c
}
n.LastChild = c
c.Parent = n
c.PrevSibling = last
}
// RemoveChild removes a node c that is a child of n. Afterwards, c will have
// no parent and no siblings.
//
// It will panic if c's parent is not n.
func (n *Node) RemoveChild(c *Node) {
if c.Parent != n {
panic("html: RemoveChild called for a non-child Node")
}
if n.FirstChild == c {
n.FirstChild = c.NextSibling
}
if c.NextSibling != nil {
c.NextSibling.PrevSibling = c.PrevSibling
}
if n.LastChild == c {
n.LastChild = c.PrevSibling
}
if c.PrevSibling != nil {
c.PrevSibling.NextSibling = c.NextSibling
}
c.Parent = nil
c.PrevSibling = nil
c.NextSibling = nil
}
// reparentChildren reparents all of src's child nodes to dst.
func reparentChildren(dst, src *Node) {
for {
child := src.FirstChild
if child == nil {
break
}
src.RemoveChild(child)
dst.AppendChild(child)
}
}
// clone returns a new node with the same type, data and attributes.
// The clone has no parent, no siblings and no children.
func (n *Node) clone() *Node {
m := &Node{
Type: n.Type,
DataAtom: n.DataAtom,
Data: n.Data,
Attr: make([]Attribute, len(n.Attr)),
}
copy(m.Attr, n.Attr)
return m
}
// nodeStack is a stack of nodes.
type nodeStack []*Node
// pop pops the stack. It will panic if s is empty.
func (s *nodeStack) pop() *Node {
i := len(*s)
n := (*s)[i-1]
*s = (*s)[:i-1]
return n
}
// top returns the most recently pushed node, or nil if s is empty.
func (s *nodeStack) top() *Node {
if i := len(*s); i > 0 {
return (*s)[i-1]
}
return nil
}
// index returns the index of the top-most occurrence of n in the stack, or -1
// if n is not present.
func (s *nodeStack) index(n *Node) int {
for i := len(*s) - 1; i >= 0; i-- {
if (*s)[i] == n {
return i
}
}
return -1
}
// insert inserts a node at the given index.
func (s *nodeStack) insert(i int, n *Node) {
(*s) = append(*s, nil)
copy((*s)[i+1:], (*s)[i:])
(*s)[i] = n
}
// remove removes a node from the stack. It is a no-op if n is not present.
func (s *nodeStack) remove(n *Node) {
i := s.index(n)
if i == -1 {
return
}
copy((*s)[i:], (*s)[i+1:])
j := len(*s) - 1
(*s)[j] = nil
*s = (*s)[:j]
}
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+271
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@@ -0,0 +1,271 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package html
import (
"bufio"
"errors"
"fmt"
"io"
"strings"
)
type writer interface {
io.Writer
io.ByteWriter
WriteString(string) (int, error)
}
// Render renders the parse tree n to the given writer.
//
// Rendering is done on a 'best effort' basis: calling Parse on the output of
// Render will always result in something similar to the original tree, but it
// is not necessarily an exact clone unless the original tree was 'well-formed'.
// 'Well-formed' is not easily specified; the HTML5 specification is
// complicated.
//
// Calling Parse on arbitrary input typically results in a 'well-formed' parse
// tree. However, it is possible for Parse to yield a 'badly-formed' parse tree.
// For example, in a 'well-formed' parse tree, no <a> element is a child of
// another <a> element: parsing "<a><a>" results in two sibling elements.
// Similarly, in a 'well-formed' parse tree, no <a> element is a child of a
// <table> element: parsing "<p><table><a>" results in a <p> with two sibling
// children; the <a> is reparented to the <table>'s parent. However, calling
// Parse on "<a><table><a>" does not return an error, but the result has an <a>
// element with an <a> child, and is therefore not 'well-formed'.
//
// Programmatically constructed trees are typically also 'well-formed', but it
// is possible to construct a tree that looks innocuous but, when rendered and
// re-parsed, results in a different tree. A simple example is that a solitary
// text node would become a tree containing <html>, <head> and <body> elements.
// Another example is that the programmatic equivalent of "a<head>b</head>c"
// becomes "<html><head><head/><body>abc</body></html>".
func Render(w io.Writer, n *Node) error {
if x, ok := w.(writer); ok {
return render(x, n)
}
buf := bufio.NewWriter(w)
if err := render(buf, n); err != nil {
return err
}
return buf.Flush()
}
// plaintextAbort is returned from render1 when a <plaintext> element
// has been rendered. No more end tags should be rendered after that.
var plaintextAbort = errors.New("html: internal error (plaintext abort)")
func render(w writer, n *Node) error {
err := render1(w, n)
if err == plaintextAbort {
err = nil
}
return err
}
func render1(w writer, n *Node) error {
// Render non-element nodes; these are the easy cases.
switch n.Type {
case ErrorNode:
return errors.New("html: cannot render an ErrorNode node")
case TextNode:
return escape(w, n.Data)
case DocumentNode:
for c := n.FirstChild; c != nil; c = c.NextSibling {
if err := render1(w, c); err != nil {
return err
}
}
return nil
case ElementNode:
// No-op.
case CommentNode:
if _, err := w.WriteString("<!--"); err != nil {
return err
}
if _, err := w.WriteString(n.Data); err != nil {
return err
}
if _, err := w.WriteString("-->"); err != nil {
return err
}
return nil
case DoctypeNode:
if _, err := w.WriteString("<!DOCTYPE "); err != nil {
return err
}
if _, err := w.WriteString(n.Data); err != nil {
return err
}
if n.Attr != nil {
var p, s string
for _, a := range n.Attr {
switch a.Key {
case "public":
p = a.Val
case "system":
s = a.Val
}
}
if p != "" {
if _, err := w.WriteString(" PUBLIC "); err != nil {
return err
}
if err := writeQuoted(w, p); err != nil {
return err
}
if s != "" {
if err := w.WriteByte(' '); err != nil {
return err
}
if err := writeQuoted(w, s); err != nil {
return err
}
}
} else if s != "" {
if _, err := w.WriteString(" SYSTEM "); err != nil {
return err
}
if err := writeQuoted(w, s); err != nil {
return err
}
}
}
return w.WriteByte('>')
default:
return errors.New("html: unknown node type")
}
// Render the <xxx> opening tag.
if err := w.WriteByte('<'); err != nil {
return err
}
if _, err := w.WriteString(n.Data); err != nil {
return err
}
for _, a := range n.Attr {
if err := w.WriteByte(' '); err != nil {
return err
}
if a.Namespace != "" {
if _, err := w.WriteString(a.Namespace); err != nil {
return err
}
if err := w.WriteByte(':'); err != nil {
return err
}
}
if _, err := w.WriteString(a.Key); err != nil {
return err
}
if _, err := w.WriteString(`="`); err != nil {
return err
}
if err := escape(w, a.Val); err != nil {
return err
}
if err := w.WriteByte('"'); err != nil {
return err
}
}
if voidElements[n.Data] {
if n.FirstChild != nil {
return fmt.Errorf("html: void element <%s> has child nodes", n.Data)
}
_, err := w.WriteString("/>")
return err
}
if err := w.WriteByte('>'); err != nil {
return err
}
// Add initial newline where there is danger of a newline beging ignored.
if c := n.FirstChild; c != nil && c.Type == TextNode && strings.HasPrefix(c.Data, "\n") {
switch n.Data {
case "pre", "listing", "textarea":
if err := w.WriteByte('\n'); err != nil {
return err
}
}
}
// Render any child nodes.
switch n.Data {
case "iframe", "noembed", "noframes", "noscript", "plaintext", "script", "style", "xmp":
for c := n.FirstChild; c != nil; c = c.NextSibling {
if c.Type == TextNode {
if _, err := w.WriteString(c.Data); err != nil {
return err
}
} else {
if err := render1(w, c); err != nil {
return err
}
}
}
if n.Data == "plaintext" {
// Don't render anything else. <plaintext> must be the
// last element in the file, with no closing tag.
return plaintextAbort
}
default:
for c := n.FirstChild; c != nil; c = c.NextSibling {
if err := render1(w, c); err != nil {
return err
}
}
}
// Render the </xxx> closing tag.
if _, err := w.WriteString("</"); err != nil {
return err
}
if _, err := w.WriteString(n.Data); err != nil {
return err
}
return w.WriteByte('>')
}
// writeQuoted writes s to w surrounded by quotes. Normally it will use double
// quotes, but if s contains a double quote, it will use single quotes.
// It is used for writing the identifiers in a doctype declaration.
// In valid HTML, they can't contain both types of quotes.
func writeQuoted(w writer, s string) error {
var q byte = '"'
if strings.Contains(s, `"`) {
q = '\''
}
if err := w.WriteByte(q); err != nil {
return err
}
if _, err := w.WriteString(s); err != nil {
return err
}
if err := w.WriteByte(q); err != nil {
return err
}
return nil
}
// Section 12.1.2, "Elements", gives this list of void elements. Void elements
// are those that can't have any contents.
var voidElements = map[string]bool{
"area": true,
"base": true,
"br": true,
"col": true,
"command": true,
"embed": true,
"hr": true,
"img": true,
"input": true,
"keygen": true,
"link": true,
"meta": true,
"param": true,
"source": true,
"track": true,
"wbr": true,
}
+1219
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+18
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@@ -105,6 +105,12 @@
"revision": "77ed1c8a01217656d2080ad51981f6e99adaa177",
"revisionTime": "2015-11-25T20:19:25Z"
},
{
"checksumSHA1": "+C5xtTR8XG1rwSVunPPRANfYolY=",
"path": "github.com/microcosm-cc/bluemonday",
"revision": "542fd4642604d0d0c26112396ce5b1a9d01eee0b",
"revisionTime": "2017-12-22T15:26:07Z"
},
{
"checksumSHA1": "rJab1YdNhQooDiBWNnt7TLWPyBU=",
"path": "github.com/pkg/errors",
@@ -136,6 +142,18 @@
"revision": "d1e1b351919c6738fdeb9893d5c998b161464f0c",
"revisionTime": "2016-12-29T22:47:41Z"
},
{
"checksumSHA1": "2t6c6F2y4b/PEV04TOHpQxh/xLc=",
"path": "golang.org/x/net/html",
"revision": "d866cfc389cec985d6fda2859936a575a55a3ab6",
"revisionTime": "2017-12-11T20:45:21Z"
},
{
"checksumSHA1": "iWvOOLdDxvI4AVX6px6/HYBPeaQ=",
"path": "golang.org/x/net/html/atom",
"revision": "d866cfc389cec985d6fda2859936a575a55a3ab6",
"revisionTime": "2017-12-11T20:45:21Z"
},
{
"checksumSHA1": "J+KmMiCOHG4E4vbd4C1BtRp813s=",
"path": "golang.org/x/oauth2",