[PM-18104] Implement generic key decryption in KeyStoreContext

[dani-garcia]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-18104

📔 Objective

Expanded a bit a POC I had to make all the key encryption and decryption methods in KeyStore generic, through the use of a ContextHasKeys trait that ensures the store knows how to handle each key type.

I've had to introduce a trait called KeyBytes to deal with how to parse each key from bytes and convert them to bytes, initially I planned to enforce that keys had a TryFrom<Vec<u8>> and TryInto<Vec<u8>>, but hit some errors with the trait solver. I'll see if there's a better way to do it, maybe Encodable/Decodable from #142?

This is using an associated type bound, which would require us to bump MSRV to 1.79 Fixed it in ce39bca

⏰ 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 – f718d9b0-2003-4db9-b3ed-6eb3f9a9cda0

Great job, no security vulnerabilities found in this Pull Request

[codecov]

Codecov Report

Attention: Patch coverage is 91.55844% with 13 lines in your changes missing coverage. Please review.

Project coverage is 65.45%. Comparing base (9e09cc5) to head (ce39bca).
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/bitwarden-crypto/src/store/context.rs	91.81%	9 Missing ⚠️
crates/bitwarden-core/src/auth/auth_client.rs	0.00%	1 Missing ⚠️
crates/bitwarden-core/src/auth/renew.rs	0.00%	1 Missing ⚠️
...s/bitwarden-core/src/client/encryption_settings.rs	80.00%	1 Missing ⚠️
crates/bitwarden-core/src/mobile/crypto.rs	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #152      +/-   ##
==========================================
+ Coverage   65.34%   65.45%   +0.10%     
==========================================
  Files         195      195              
  Lines       15087    15052      -35     
==========================================
- Hits         9859     9852       -7     
+ Misses       5228     5200      -28     

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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