<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#44376
I opted for an in-memory cache here, as it's not a critical cache piece,
we are fine with the cache being different times on different containers
(just means some might rotate to the correct cert faster than 5
minutes).
It's also a small piece of work, rather than pulling in redis etc.
Verified that it now logs, if the cert is stale after a 5 minute
in-memory cache.
```
ts=2026-05-07T11:30:08Z level=info msg="push certificate is stale after re-checking" topic=com.apple.mgmt.External.34c4a9b0-6501-4ce6-afc6-32eac6420ee7 staleToken="\x90C\xe4K\xc6a\x97\xb5?\x1b\x9a\x04'\xe7b\x8d" newHash=".fP\xc7O7\xab\xab\x9d\x92\xd5#\xe4u\xe0\xf6"
ts=2026-05-07T11:30:08Z level=info component=apple-mdm-push msg="retrieved push cert" topic=com.apple.mgmt.External.34c4a9b0-6501-4ce6-afc6-32eac6420ee7
```
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
- [x] Timeouts are implemented and retries are limited to avoid infinite
loops
- [x] If paths of existing endpoints are modified without backwards
compatibility, checked the frontend/CLI for any necessary changes
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* APNs push certificates now refresh in-memory when rotated; staleness
is detected using certificate checksums with a short grace window.
* **Tests**
* Added tests for certificate retrieval, staleness detection/refresh
behavior, and push-cert storage error handling.
* **Documentation**
* Updated docs to describe the APNs push-certificate refresh and
staleness behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Magnus Jensen
034691966f