Wallet event parsers accept unauthenticated events

Summary

The NIP-47 response and notification parsers and the NIP-60 wallet event parsers decrypted relay-provided events before verifying their kind, computed event ID, signature, and expected wallet public key. The decryption peer was derived from the untrusted event author, so successful decryption did not prove that the configured wallet created the event.

An attacker can sign an event with their own key and derive the corresponding shared secret with the victim's public key. A malicious relay delivering that event could therefore cause attacker-chosen encrypted content to be parsed as a response, notification, token, spending record, or quote from the configured wallet. This can corrupt wallet state or cause an application to act on forged wallet data. The issue does not expose the victim's private key or decrypt events authored by the legitimate wallet.

The affected parsers now verify the event kind, ID, signature, and exact configured wallet author before attempting decryption or parsing the plaintext.