now implement a different strategy for choosing whether there will be any
change, and its value. The aims are:
* Ensure that it is possible to create fully transparent transactions with
no change (this will be needed for ZIP 320). The `InsufficientFunds`
error in this case should have a `required` field that reflects the
additional amount needed, according to the fee calculated without an
extra change output.
* Avoid leaking information about note amounts in some cases: an adversary
that knew the number of external recipients and the sum of their outputs
was able to learn the sum of the inputs if no change output was present.
* Defend against losing money by using `DustAction::AddDustToFee` with a
too-high dust threshold.
* Ensure that if a "change memo" is requested, there will always be a
shielded change output in which to put it. Previously, this would not
be the case when using `DustAction::AddDustToFee`.
Co-authored-by: Jack Grigg <jack@electriccoin.co>
Co-authored-by: Kris Nuttycombe <kris@nutty.land>
Signed-off-by: Daira-Emma Hopwood <daira@jacaranda.org>
if a memo is given for the transparent pool. Use `ChangeValue::shielded`
to avoid this error case when creating a `ChangeValue` known to be for a
shielded pool.
Co-authored-by: Jack Grigg <jack@electriccoin.co>
Signed-off-by: Daira-Emma Hopwood <daira@jacaranda.org>
changing its type from `ShieldedProtocol` to `PoolType`.
Also fix compilation errors when the "orchard" feature is used without
the "transparent-inputs" feature.
Signed-off-by: Daira-Emma Hopwood <daira@jacaranda.org>
Prior to this change, the recipient of a sent transaction would always
be shown as the protocol-level address, instead of any unified address
intended as the recipient. Now, instead of reencoding the recipient
address, we use the original `ZcashAddress` value from the payment
request.
This implements the necessary state machine for taking a wallet in some
arbitrary synchronization status, and fully scanning (the remainder of)
the chain.
Closeszcash/librustzcash#1169.
Previously, if the funding account for a received transaction output was
determined to be an account known to the wallet, the output was recorded
as though it were sent to an internal (change) address of the wallet.
During wallet migration in particular, the absence of _any_ accounts is
expected, and all seeds should be treated as relevant (because accounts
cannot be added before a wallet is initialized).
This should never have had the behavior of returning an error on a
missing txid in the first place; doing so conflates database corruption
or connectivity errors with the ordinary case where data may not be
available.
Jack Grigg
Kris Nuttycombe
Daira-Emma Hopwood
oscar-pepper
Andrew Arnott