[PM-22812] Attachments get corrupted when downgrading from cipherkeys

[gbubemismith]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-22812

📔 Objective

Editing a cipher with attachments causes attachment corruption when switching between cipher-key encryption and user-key encryption in either direction. The SDK's AttachmentView was not providing the decrypted attachment key needed for re-encryption scenarios. When the cipher gets re-encrypted between different encryption contexts (cipher-key ↔ user-key) during save, the client needs the decrypted attachment key to properly re-encrypt it under the new encryption context. Without this, null gets posted for the attachment key, breaking decryption.

This is a temporary solution during the migration from TypeScript to the SDK. The decrypted_key field should be removed once all encryption logic is handled within the SDK.

Cleanup tracked in: https://bitwarden.atlassian.net/browse/PM-23005

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation
  team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed
  issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

Checkmarx One – Scan Summary & Details – bcfab106-6109-4fb3-82f2-5c38656e8e00

Great job, no security vulnerabilities found in this Pull Request

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.20%. Comparing base (17866c0) to head (e52bc41).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #328      +/-   ##
==========================================
- Coverage   71.75%   71.20%   -0.56%     
==========================================
  Files         224      230       +6     
  Lines       18385    18647     +262     
==========================================
+ Hits        13193    13278      +85     
- Misses       5192     5369     +177     

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud