GHSA-8h88-gxp3-j7pg

### Summary

The `PublicKeyBundle.from_dict()` method in `openssl_encrypt/modules/key_bundle.py` at **lines 329-361** creates bundles from untrusted data without verifying the signature. The docstring warns to call `verify_signature()` after creation, but the `to_identity()` method (line 363-391) can convert an unverified bundle directly to an `Identity` object.

### Affected Code

```python @classmethod def from_dict(cls, data: Dict) -> "PublicKeyBundle": """ SECURITY: Does NOT verify signature. Call verify_signature() after creation. """ # Creates bundle without verification ```

### Impact

If `from_dict()` followed by `to_identity()` is called without an intervening `verify_signature()` call, encryption could be performed against an attacker's public key, leaking secrets. While `key_resolver.py` (lines 146-147) does verify before use, the unguarded API path remains directly callable.

### Recommended Fix

- Add a `verified` flag to `PublicKeyBundle` that must be set before `to_identity()` can be called - Or have `to_identity()` automatically call `verify_signature()` and raise on failure - Or make `from_dict()` require verification as part of construction

### Fix

Fixed in commit `f4a1ba6` on branch `releases/1.4.x` — from_dict() now verifies self_signature by default (verify=True parameter); raises ValueError on verification failure.