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Firefox 146 supports compressed ECC key point format #28497

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Merged
hamishwillee merged 6 commits into from
Dec 9, 2025
+166 −2
Merged

Firefox 146 supports compressed ECC key point format #28497

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a22caa7
EC compressed data supported on import of EC key
hamishwillee Nov 21, 2025
342e6bc
Update api/SubtleCrypto.json
hamishwillee Nov 25, 2025
a380a85
Add spec link
hamishwillee Dec 2, 2025
e771fb0
Add subkeys for ECDH, ECDSA
hamishwillee Dec 8, 2025
851078d
Update api/SubtleCrypto.json
hamishwillee Dec 8, 2025
bfec9e8
Apply suggestions from code review
hamishwillee Dec 9, 2025
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37 changes: 37 additions & 0 deletions api/SubtleCrypto.json
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Expand Up @@ -1158,6 +1158,43 @@
"deprecated": false
}
},
"compressed_ec_points": {
"__compat": {
"description": "ECDSA or ECDH key data can contain compressed elliptic curve points.",
"support": {
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@caugner caugner Nov 25, 2025

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Isn't there any spec section that we could link?

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@caugner caugner Nov 25, 2025

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It seems that support for compressed points is not mandatory, see: https://w3c.github.io/webcrypto/#:~:text=The%20uncompressed%20point%20format%20MUST%20be%20supported%2E

From BCD's point of view, this would warrant setting standard_track: false.

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@hamishwillee hamishwillee Nov 25, 2025

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Really? That makes no sense to me.

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@caugner caugner Nov 27, 2025

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@hamishwillee If you come to the same conclusion as me looking at the phrasing in the spec, would you like to file a spec issue asking for clarification?

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@hamishwillee hamishwillee Dec 2, 2025

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@caugner Sorry for the delay - went away for a few days.

Yes, support for compressed points is not mandatory - I don't think there is any doubt about that and I wouldn't request clarification.

The bit I don't understand is this:

From BCD's point of view, this would warrant setting standard_track: false.

It doesn't make sense to me that something not being mandatory means that it is "not on the standards track" - in particular because the behaviour when EC uncompressed points are discovered is explicitly and clearly documented in the spec at the point you linked.

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@hamishwillee hamishwillee Dec 2, 2025 •
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So assuming you agree and I just wasn't clear about my confusion originally, I added the spec url in a380a85

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@caugner caugner Dec 2, 2025

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Let's get a second opinion from @ddbeck here.

My understanding is we treat non-mandatory and non-normative features in BCD as non-standard, as if it wasn't described at all. The most recent case might have been this input picker UI behavior.

However, we only mention "mandatory specified behavior" in the partial implementation guidelines.

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@hamishwillee hamishwillee Dec 2, 2025

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Thank you. Obviously whatever the rules are we will follow.

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@ddbeck ddbeck Dec 5, 2025

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I read this bit of the spec:

If the implementation does not support the compressed point format and a compressed point is provided, throw a DataError.

to mean that a browser may support compressed points, but doesn't have to (unlike the uncompressed points). Therefore this is optional normative behavior and it's fine if this has a spec URL and "standard_track": true.

I'd expect these support scenarios for this feature:

  • Accepts a compressed point → supported
  • Throws a DataError → unsupported
  • Does anything else → partial implementation

"chrome": {
"version_added": "≤80"
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@hamishwillee hamishwillee Nov 21, 2025

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80 is the earliest version of chrome the the test I am using works for https://wpt.live/WebCryptoAPI/import_export/ec_importKey.https.any.html

},
"chrome_android": "mirror",
"deno": {
"version_added": false
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@hamishwillee hamishwillee Nov 21, 2025

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Can't find information on node or deno so have set as false.

},
"edge": "mirror",
"firefox": {
"version_added": "146"
},
"firefox_android": "mirror",
"nodejs": {
"version_added": false
},
"oculus": "mirror",
"opera": "mirror",
"opera_android": "mirror",
"safari": {
"version_added": false
},
"safari_ios": "mirror",
"samsunginternet_android": "mirror",
"webview_android": "mirror",
"webview_ios": "mirror"
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"ed25519": {
"__compat": {
"description": "`Ed25519` algorithm",
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