verifySignedTx compared only from, to, value and data, so a signed
transaction could differ from the approval in chain id, nonce, gas limit
or any fee field and still be broadcast. Worse, it named the fields it
checked and so admitted every field it did not name: a type 4 artifact
carrying an EIP-7702 authorization passed verification, paying the
approved amount to the approved recipient and, in the same transaction,
permanently installing another contract's code at the signer's own
account.
The check is now an allowlist in both directions. The transaction type
must be 0, 1 or 2 — the only types this wallet signs — so no later
EIP-2718 type can bring a field along; authorizationList, blobs, blob
commitments and blob gas fees are refused by name; and the access list
is compared with the approval. Every consequential field is compared and
any mismatch refuses outright: the chain id against the selected network
(and against the approval when the page fixed one), plus nonce, gas
limit, gasPrice, maxFeePerGas and maxPriorityFeePerGas wherever the
approval carries a value, together with the fee mechanism the approval
implies. Fields the approval does not carry are populated locally by the
popup and have no approved value to compare against, so they are held to
absolute ceilings instead. Verification then closes by rebuilding the
transaction from exactly those checked fields and comparing the unsigned
bytes, so an artifact carrying anything this module does not account for
is refused without having to be named first.
An approved value that is not a number now refuses like every other
quantity rather than escaping as a raw BigInt conversion error, which
was reported as retryable and left a live button that could never
succeed.
A failed signing attempt also left a button that could not succeed: the
background deleted the approval before it broadcast, so a retry found
nothing to sign. The approval is now retired once the request has an
outcome, and the background tells the popup which stage failed. A popup
that could not sign is retryable; a mismatch spends the approval; a
failed broadcast is terminal, because the node may have accepted the
transaction and still failed to answer and the popup's retry re-signs at
a freshly fetched nonce rather than re-broadcasting the same bytes,
which would send the approved transfer twice.
The password no longer crosses the extension messaging boundary: the popup
decrypts and signs, and sends only the raw signed transaction or the signature.
The background re-derives the signer from the artifact and checks it against
the approval it holds before broadcasting, so it is not a blind relay.
