Trusted types attributes #1268

lukewarlow · 2024-03-27T19:22:16Z

This calls the get Trusted Types-compliant attribute value algorithm from Trusted Types (w3c/trusted-types#418) from attribute's change, append, and replace.

Changed the signature of setAttribute and setAttributeNS to accept Trusted Types as values. The underlying Attr node's values continue to be DOMString, so moving nodes across elements or adding standalone attributes to elements can cause TT violations. This matches WPT tests and the Chromium's implementation.

See and #789. Supercedes #809 and #1247

At least two implementers are interested (and none opposed):
- Chromium
- Gecko
Tests are written and can be reviewed and commented upon at:
- https://github.com/web-platform-tests/wpt/tree/master/trusted-types
Implementation bugs are filed:
- Chromium:https://bugs.chromium.org/p/chromium/issues/detail?id=739170
- Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=1508286
- WebKit: https://bugs.webkit.org/show_bug.cgi?id=266630
MDN issue is filed: …
The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

Preview | Diff

lukewarlow · 2024-03-27T19:22:41Z

This is a clone of #1247 where I will finish any outstanding work to get this across the line

lukewarlow · 2024-04-11T12:21:53Z

See also #1258 which is another integration point with the DOM spec that we need for TT.

dom.bs

otherdaniel · 2024-04-15T17:13:57Z

dom.bs

+   <li><p><a>Validate and set attribute value</a> <var>attr</var>'s <a for="Attr">value</a> for
+   <var>attr</var> with <var>element</var>.
+
+   <li><p>If <var>element</var> <a lt="has an attribute">has</a> an <a>attribute</a>


I still find it difficult to wrap my head around this logic. I think conceptually, we want to have the old value -- from before the call, and thus before a default policy might have mucked with it. That's what should go into the change attribute logic. But once we have that, I'm not sure why we'd need to throw an exception here. I'm not sure why we'd have to care whether the default policy does anything funny with the attribute in the mean time.

I've read through this spec path and I believe that, if the default policy removes the existing attribute node, then this will call replace an attribute, which in turn calls replace a list item, which results in a no-op because the old value no longer exists to be replaced.

So I think in this situation you're probably right the spec doesn't need to do anything, will make that change.

Having said that I'm slightly uneasy about stuff like attribute change steps still firing and how that all works spec wise.

Both Chromium and WebKit don't actually follow the spec 100% here and so I think would actually result in a different behaviour to this spec (the index lookup happens after the TT call) so that's also not ideal.

lukewarlow · 2024-04-22T13:18:23Z

I think I've addressed all the comments from #1247.

I do want to point out Chrome and WebKit don't (or at least not in a way obvious to me) 100% follow the flow of the spec and as a result this may result in differences specifically in weird cases with attribute mutation.

So that bit especially it would be good to get feedback on.

It's also worth being aware that like Chromium's implementation this spec means that certain ways to update a nodes value don't work with a trusted type object as a user might expect. (e.g. iframe.getAttributeNode('srcdoc').value = trustedHTMLObj; will throw unless allowed by a default policy). I think in pratice this will be fine, and in some cases is the only real option we have without nodes keeping track of whether they're trusted or not (which would add lots of complexity)

annevk

This change is either incomplete or makes many cosmetic changes that would be best proposed separately as they confuse me quite a bit.

dom.bs

lukewarlow · 2024-04-22T15:47:56Z

This change is either incomplete or makes many cosmetic changes that would be best proposed separately as they confuse me quite a bit.

Apologies I thought I'd reverted all of these changes but I missed a few, it's because I changed stuff and then changed it back and this led to some wonky diffs. Have hopefully reverted all of these unnecessary changes

annevk · 2024-04-22T16:07:37Z

dom.bs

+ <li><p>If <var>attribute</var>'s <a for=Attr>element</a> <a lt="has an attribute">has</a>
+ an <a>attribute</a> <var>attribute</var>, then <a>handle attribute changes</a> for
+ <var>attribute</var> with <var>attribute</var>'s <a for=Attr>element</a>, <var>oldValue</var>, and
+ <var>value</var>.


Should this be value or attribute's value? They can be different, right?

dom.bs

lukewarlow · 2024-05-07T15:54:52Z

@otherdaniel, @annevk , and @smaug---- regarding the case where the default policy changes assumptions about the existence of an attribute mid-way through what would you prefer the spec say to do? Currently I've specced to throw, but Chromium currently re-looks up the index (spec doesn't explicitly work on an index basis but Chromium and WebKit do)

annevk · 2024-05-13T14:58:26Z

Attributes are stored in a list and those do have indices per Infra. What am I missing?

lukewarlow · 2024-05-13T15:03:24Z

Sorry I mean algorithmically the spec and implementations don't follow the same flow. So it's trickier to reason between the spec and implementation. This might just be my lack of familiarity with these APIs too.

annevk · 2024-05-13T15:11:38Z

The path of least resistance is prolly matching Chromium. Introducing new paths that throw is always risky. If you are looking for guidance as to how, I'd need quite a bit more context to provide helpful suggestions.

…an attribute

… Chrome.

…erved in Chrome." This reverts commit 2f00466.

This reverts commit 6e40964.

…ent by the default policy

lukewarlow · 2025-02-20T14:57:35Z

I've pushed up the change to "set an attribute", and to "set an existing attribute value".

I'm looking into the setAttribute methods now.

Attr.value/.nodeValue/.textContent should do validation (if there is element) too before modifying the value.
(chromium and webkit seem to do something else, assuming I'm reading the code correctly)

WebKit at least calls element->setAttribute so the TT check happens slightly later and this can lead to the logic running on the wrong element.

I've updated the spec to make it clearer what should happen here. I believe this is slightly different to Firefox's recently implementation so will need test changes.

Element.setAttribute/Element.setAttributeNS in the PR needs some tweaking too. Implementations don't necessarily create Attr nodes when those APIs are used, but if they do, what happens if TT callback moves the Attr away. As fred-wang mentioned earlier, implementations already just create a new attribute on the element.

I'll investigate what Firefox is doing here and see what the best approach to take is. Generally it seems we want to move TT earlier in the process if possible so I'll try to achieve that.

Perhaps we can move step 6 higher up, but it would have to be after step 3 at the earliest.

annevk

I did a quick editorial review. Please double check the comments throughout as some apply several times.

dom.bs

annevk · 2025-02-20T15:39:11Z

dom.bs

+ <li><p>Let <var>verifiedValue</var> be the result of calling <a>verify attribute value</a>
+ <var>attr</var>'s <a for=Attr>value</a> for <var>attr</var>, with <var>element</var>.


Suggested change

<li><p>Let <var>verifiedValue</var> be the result of calling <a>verify attribute value</a>

<var>attr</var>'s <a for=Attr>value</a> for <var>attr</var>, with <var>element</var>.

<li><p>Let <var>verifiedValue</var> be the result of <a>verifying attribute value</a> given

<var>attr</var>'s <a for=Attr>value</a>, <var>attr</var>, and <var>element</var>.

However, this doesn't match the signature above. What gives?

I've updated this and the signature to hopefully be clearer. I think it does match the signature it was just written rather poorly. I've changed the signature to a more convetional one and updated the call sites accordingly.

dom.bs

annevk · 2025-02-20T15:41:05Z

dom.bs

+   <li><p>Set <var>verifiedValue</var> to the result of calling <a>verify attribute value</a>
+   <var>value</var> for <var>attribute</var>, with <var>element</var>.
+
+   <li><p>Set <var>attributeExists</var> to true if <var>element</var> <a lt="has an attribute">has


No newlines in phrasing level elements.

I think I've addressed all of these, will check the github diff to make sure

dom.bs

If the TT callback changed removed the attr from an element then we set its standalone value and return. If the TT callback changed the attrs element to a different element we now early return.

annevk · 2025-02-20T16:21:49Z

dom.bs

-<a for=/>element</a> <var>element</var>, a string <var>localName</var>, a string <var>value</var>,
-an optional null or string <var>prefix</var> (default null), and an optional null or string
-<var>namespace</var> (default null):
+<p>To <dfn export id=concept-element-attributes-set-value>set an attribute value</dfn> given an <a


No wrapping in phrasing-level elements.

annevk · 2025-02-20T16:22:04Z

dom.bs

- return.
+ <li><p>Let <var>attributeExists</var> be false if <var>attribute</var> is null; otherwise true.
+
+ <li><p>If <var>attributeExists</var> is false, set <var>attribute</var> to an <a>attribute</a>


annevk · 2025-02-20T16:22:20Z

dom.bs

+ <li><p>If <var>attributeExists</var> is false, set <var>attribute</var> to an <a>attribute</a>
+ whose <a for=Attr>namespace</a> is <var>namespace</var>, <a for=Attr>namespace prefix</a> is
+ <var>prefix</var>, <a for=Attr>local name</a> is <var>localName</var>, <a for=Attr>value</a> is
+ <var>value</var>, and <a for=Node>node document</a> is <var>element</var>'s <a for=Node>node


No wrapping in phrasing

annevk · 2025-02-20T16:22:56Z

dom.bs

+  <p>If <var>verify</var> is true:
+
+  <ol>
+   <li><p>Set <var>verifiedValue</var> to the result of calling <a>verify attribute value</a>


"result of verifying an attribute" is nicer. And it should work with Bikeshed.

annevk · 2025-02-20T16:23:18Z

dom.bs

@@ -6641,6 +6651,9 @@ string <var>namespace</var> (default null):</p>
 <a for=/>attribute</a> <var>attr</var> and an <a for=/>element</a> <var>element</var>:

 <ol>
+ <li><p>Let <var>verifiedValue</var> be the result of calling <a>verify attribute value</a>


"result of verifying an attribute value"

annevk · 2025-02-20T16:23:40Z

dom.bs

+ whose <a for=Attr>local name</a> is <var>qualifiedName</var>, <a for=Attr>value</a> is
+ <var>value</var>, and <a for=Node>node document</a> is <a>this</a>'s <a for=Node>node document</a>.
+
+ <li><p>Let <var>verifiedValue</var> be the result of calling <a>verify attribute value</a>


"result of verifying"

lukewarlow force-pushed the trusted-types-attributes branch 2 times, most recently from 3562fcb to ac5b4aa Compare April 10, 2024 15:52

lukewarlow mentioned this pull request Apr 11, 2024

Draft integration with Trusted Types, take 2. #1247

Closed

5 tasks

lukewarlow force-pushed the trusted-types-attributes branch from 524d8cd to f8877b6 Compare April 11, 2024 12:18

lukewarlow marked this pull request as ready for review April 11, 2024 12:21

lukewarlow marked this pull request as draft April 15, 2024 10:22

lukewarlow force-pushed the trusted-types-attributes branch from f8877b6 to ee9915e Compare April 15, 2024 11:45

otherdaniel reviewed Apr 15, 2024

View reviewed changes

dom.bs Outdated Show resolved Hide resolved

otherdaniel reviewed Apr 15, 2024

View reviewed changes

lukewarlow marked this pull request as ready for review April 22, 2024 12:53

lukewarlow requested review from annevk and smaug---- April 22, 2024 13:13

lukewarlow force-pushed the trusted-types-attributes branch from ba80870 to 36476b5 Compare April 22, 2024 13:57

lukewarlow mentioned this pull request Apr 22, 2024

[Meta] Upstream changes w3c/trusted-types#476

Open

annevk reviewed Apr 22, 2024

View reviewed changes

dom.bs Outdated Show resolved Hide resolved

dom.bs Outdated Show resolved Hide resolved

dom.bs Outdated Show resolved Hide resolved

dom.bs Outdated Show resolved Hide resolved

dom.bs Outdated Show resolved Hide resolved

lukewarlow force-pushed the trusted-types-attributes branch from 370f5c9 to 4421d50 Compare April 22, 2024 15:46

lukewarlow force-pushed the trusted-types-attributes branch 2 times, most recently from 1d42460 to 1eeaf00 Compare April 22, 2024 15:52

annevk reviewed Apr 22, 2024

View reviewed changes

lukewarlow force-pushed the trusted-types-attributes branch 2 times, most recently from 4089eaf to 02db8c7 Compare May 16, 2024 15:41

lukewarlow requested a review from otherdaniel May 16, 2024 15:43

koto and others added 24 commits February 20, 2025 13:40

Removed stringification.

952f576

Fixed formatting.

588bd9f

Fixed copy-paste error in setAttribute() and indentation.

72cf8f9

Fix build

cb2fdbb

Change code to pass sink values through to TT code.

2a00536

Move validate and set attribute into append an attribute

316965c

Remove sink values from spec

8569042

Revert changes to setAttributeNode and setAttributeNodeNS method steps

7027be5

Remove throw from set an attribute and move TT check down to replace …

ac21ffe

…an attribute

Revert unneeded changes

03dc3fe

Address comment

ae5ba7a

Add missing and

3b607af

Address some comments

6726a50

Re-add early return

93251d0

Change dfn to use given rather than with

0fbb13c

Update how the enforcement is done

e9280a4

Add tentative enforcement for toggleAttribute

daa8d86

Update enforcement for toggleAttribute to match behaviour observed in…

f8e9015

… Chrome.

Revert "Update enforcement for toggleAttribute to match behaviour obs…

7b4a995

…erved in Chrome." This reverts commit 2f00466.

Revert "Add tentative enforcement for toggleAttribute"

0b3bc48

This reverts commit 6e40964.

Reintroduce infrastructure changes

d96fb19

Add step to verify that the attr hasn't been assigned to another elem…

73fa482

…ent by the default policy

Run specfmt

fdb686b

Update set an attribute to verify attribute value as first step

b047352

lukewarlow force-pushed the trusted-types-attributes branch from 622f78d to b047352 Compare February 20, 2025 14:47

annevk reviewed Feb 20, 2025

View reviewed changes

lukewarlow added 2 commits February 20, 2025 15:43

Update set an existing attribute value

5f234a4

If the TT callback changed removed the attr from an element then we set its standalone value and return. If the TT callback changed the attrs element to a different element we now early return.

Address editorial feedback

6b2fff6

annevk reviewed Feb 20, 2025

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Trusted types attributes #1268

Trusted types attributes #1268

lukewarlow commented Mar 27, 2024 •

edited by pr-preview bot

Loading

lukewarlow commented Mar 27, 2024

lukewarlow commented Apr 11, 2024

otherdaniel Apr 15, 2024

lukewarlow Apr 22, 2024

lukewarlow Apr 22, 2024

lukewarlow commented Apr 22, 2024

annevk left a comment

lukewarlow commented Apr 22, 2024

annevk Apr 22, 2024

lukewarlow commented May 7, 2024 •

edited

Loading

annevk commented May 13, 2024

lukewarlow commented May 13, 2024

annevk commented May 13, 2024

lukewarlow commented Feb 20, 2025 •

edited

Loading

annevk left a comment

annevk Feb 20, 2025

lukewarlow Feb 20, 2025

annevk Feb 20, 2025

lukewarlow Feb 20, 2025

annevk Feb 20, 2025

annevk Feb 20, 2025

annevk Feb 20, 2025

annevk Feb 20, 2025

annevk Feb 20, 2025

annevk Feb 20, 2025

		<li><p>Let <var>verifiedValue</var> be the result of calling <a>verify attribute value</a>
		<var>attr</var>'s <a for=Attr>value</a> for <var>attr</var>, with <var>element</var>.

Trusted types attributes #1268

Are you sure you want to change the base?

Trusted types attributes #1268

Conversation

lukewarlow commented Mar 27, 2024 • edited by pr-preview bot Loading

lukewarlow commented Mar 27, 2024

lukewarlow commented Apr 11, 2024

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

lukewarlow commented Apr 22, 2024

annevk left a comment

Choose a reason for hiding this comment

lukewarlow commented Apr 22, 2024

Choose a reason for hiding this comment

lukewarlow commented May 7, 2024 • edited Loading

annevk commented May 13, 2024

lukewarlow commented May 13, 2024

annevk commented May 13, 2024

lukewarlow commented Feb 20, 2025 • edited Loading

annevk left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

lukewarlow commented Mar 27, 2024 •

edited by pr-preview bot

Loading

lukewarlow commented May 7, 2024 •

edited

Loading

lukewarlow commented Feb 20, 2025 •

edited

Loading