fix(webauthn): include backup flag check in registration

[james-d-elliott]

This includes the check in §7.1 to the registration handler.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 6067ceb8-a988-4325-8b6b-e8627a16cfca

📥 Commits

Reviewing files that changed from the base of the PR and between 0661c81 and a31e321.

📒 Files selected for processing (2)

• webauthn/registration.go
• webauthn/registration_test.go

---

Walkthrough

CreateCredential now rejects registration responses with Backup State set while Backup Eligible is unset. Tests add configurable authenticator flags and verify the invalid combination returns the expected validation error.

Changes

Backup flag validation

Layer / File(s)	Summary
Registration validation and test coverage webauthn/registration.go, webauthn/registration_test.go	CreateCredential rejects invalid backup flag combinations. Registration tests modify authenticator flags and verify that no credential is returned with the expected error.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• go-webauthn/webauthn#445: Documents related WebAuthn backup-flag validation behavior.

Poem

A rabbit checked the flags in flight,
“Backup State needs eligibility right.”
Tests changed the bytes with care,
Invalid credentials stop there.
Hop, hop—validation is bright!

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-be-bs

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.24%. Comparing base (0661c81) to head (a31e321).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #748   +/-   ##
=======================================
  Coverage   88.24%   88.24%           
=======================================
  Files          57       57           
  Lines        5853     5855    +2     
=======================================
+ Hits         5165     5167    +2     
  Misses        417      417           
  Partials      271      271           

Files with missing lines	Coverage Δ
webauthn/registration.go	96.36% <100.00%> (+0.06%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.