validate private keys

[rrrooommmaaa]

This PR validates all private key packets on decrypt or on parse (if they are unencrypted)

close #0000 // if this PR closes an issue

---

Tests (delete all except exactly one):

• Tests added or updated

---

To be filled by reviewers

I have reviewed that this PR... (tick whichever items you personally focused on during this review):

• addresses the issue it closes (if any)
• code is readable and understandable
• is accompanied with tests, or tests are not needed
• is free of vulnerabilities
• is documented clearly and usefully, or doesn't need documentation

[tomholub]

👍

[tomholub]

@martgil I think you had issue reproducing the problem. You can ask here. Did you try to put the broken key into inbox and then load it? If it succeeded, then with the above PR it should fail - please triage.

[martgil]

Did you try to put the broken key into inbox and then load it?

Yes, that's exactly what I did.

If it succeeded, then with the above PR it should fail - please triage.

Yes @tomholub, the private key is blocked and no longer accepted when a user tried to import/add it.

The android and ios are currently affected by the bug. Maybe they are not aware of it just yet.
I can file a GitHub issue for each repo if you'd like.

[tomholub]

@martgil yes, please file the issues there. For Android, ping @IvanPizhenko so that he can maybe create a test case for Paul to look at.