openssl-encrypt's unverified key bundle from_dict() + to_identity() path allows encryption to attacker keys

Overview

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

@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.

Affected packages

• openssl-encrypt < 1.4.0

Remediation

Upgrade to a patched release:

• openssl-encrypt 1.4.0