LibWeb: Implement ECDH.generateKey

[devgianlu]

Fixes some tests in https://wpt.live/WebCryptoAPI/derive_bits_keys/pbkdf2.https.any.html?1-1000 by having a working ECDH generateKey so that ... with wrong (ECDH) key tests pass.

[rmg-x]

We probably want in-tree tests for this, see Documentation/Testing.md for how to create them.

Once you have one created, you can run an individual LibWeb test with this command:

Meta/ladybird.sh run headless-browser --run-tests $PWD/Tests/LibWeb --force-fontconfig -f your-test-name.html

[devgianlu]

We probably want in-tree tests for this, see Documentation/Testing.md for how to create them.

Should I add to Tests/LibWeb/Text/input/Crypto/SubtleCrypto-generateKey.html?

EDIT: Looks like it is excluded for being Flaky on CI

[rmg-x]

That seems fine to me, but I'm not a maintainer. It looks like that only has RSA-OAEP key generation currently but the name definitely implies it should be more generic so...

[rmg-x]

On a recent PR I did for AES-GCM (#2143), I just created a separate file Crypto/SubtleCrypto-aesgcm.html for the cases that were fixed.

[gmta]

Welcome @devgianlu !

Note that you do not necessarily need to write your own test if there's a proper WPT test case for it! Using Meta/import-wpt-tests.py you can pull in a test case covering ECDH and use the expected result file to mark which tests are expected to pass, and which still fail.

[devgianlu]

Thanks @gmta!

I've looked deeper into the tests situation and it looks this fixes a bunch of stuff in https://wpt.live/WebCryptoAPI/generateKey/successes_ECDH.https.any.html and https://wpt.live/WebCryptoAPI/generateKey/failures_ECDH.https.any.html too, so I've imported those.