this script relies on a secretTextarea having an specific class, but that's not supported in the taglib. Therefore, there was a javascript error preventing the form validations from being updated. The plugin is behaving as expected, and this issue is merely a UX issue.

Note 1: Although this was detected working on FIPS mode, this is not a real FIPS issue
Note 2: This issue is not blocking, the page still works. Simply it's a bit annoying to see that the form validation messages are not updated

Testing done

1. Open the javascript console
2. Go to Manage Jenkins > Credentials
3. Select a Domain
4. Click on Add Credentials
5. Select SSH Username with private key
6. Click on Enter directly
7. Enter a ciphered private key
8. Enter the passphrase

With the code in master you'll see an error in the javascript console
With the fix, the javascript error isn't there.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue