`std::visit(match {...}, specimen)`, improving code readability.
For ease of review, this commit includes only obviously correct
transformations that all follow the same pattern.
Signed-off-by: Daira Emma Hopwood <daira@jacaranda.org>
- Remove `std::optional` from a number of uses,
- simplify `GetUFVKMetadataForAddress` to `GetUFVKIdForAddress`, and
- add a new `GetUFVKMetadataForAddress` as a wrapper around
`GetUFVKMetadataForReceiver`.
This now returns whether or not the address corresponds to an
internal recipient, an external address for the wallet, or a
counterparty's address (an address not derived from any of
the wallet's keys) from GetPaymentAddressForRecipient.
Fixes#5708
One of the invariants that we want to hold for unified addresses
is that we never want change addresses to be visible to users.
This updates address metadata retrieval to also indicate whether
or not an address is associated with a UFVK's internal key,
and omits and flags change addresses in z_viewtransaction output.
The methods `FindUnifiedFullViewingKey` and `FindUFVKByReceiver`
are implementable with only the information that'a available from
the keystore, so it's better to use the methods that are defined
there in the previous commit.
When a user supplies a unified address as the source of funds
for z_sendmany, the previous behavior could have risked user
privacy by spending transparent UTXOs belonging to different
diversified addresses in the same transaction, thereby linking
those addresses, and consequently any diversified shielded
receivers of unified addresses containing those transparent
receivers.
This change limits selection of transparent UTXOs to only those
explicitly associated with the unified receivers of the provided
source UA. Also, if a UA is provided as the source, the behavior
is maintained that only shielded notes in pools corresponding to
the receivers of that UA will be selected.
This ensures we have the same semantics for detecting Orchard and
Sapling receivers in UAs, even if the UA they are part of was derived
outside of the zcashd wallet.
Adding the default address to the wallet automatically made sense
prior to support of diversified addresses, but this is no longer
desirable behavior as we have separated key generation from address
derivation.
This operation was poorly named; the wallet already contained
the IVK, and this operation was simply adding the ability to
look up the IVK by a specific diversified address derived
from that IVK.
This reworks the way that address metadata is added to the wallet
to make adding address metadata to the wallet's in-memory cache
the responsibility of a single method rather than distributed
across multiple places in the code.
This changes ZcashdUnifiedSpendingKey::ToUnifiedFullViewingKey
to return a `UnifiedFullViewingKey` object. This makes the
derivation of ZcashdUnifiedFullViewingKey values more regular,
removing the need to be able to construct these values directly
from the spending key.
This change also modifies ZcashdUnifiedSpendingKey to remove
the `std::optional` wrapper from its member keys. This
optionality is spurious, because it is always possible to
derive a "complete" spending key, and we do not support
import of unified spending keys.
In order to support generation of unified addresses, it needs
to be possible for the code generating a unified address to search
the space of Sapling diversifiers to obtain a valid diversifier.
Historically, invalid diviersifiers were simply skipped, so we retain
this behavior when obtaining a Sapling address from the legacy HD seed.
All of these maps are created from scratch on wallet load, so we can
alter their contents without compatibility concerns. With this change,
we can use the existing maps to implement viewing key support. The
downside is that the wallet will take more space in memory, but that can
easily be improved in future by storing ExtFVK fingerprints in some of
the maps (which would improve memory usage even compared to the original
layout).
The wallet now only stores Sapling extended spending keys, and thus can
only be used with keys generated from an HDSeed via ZIP 32.
Note that not all Sapling keys in the wallet will correspond to the
wallet's HDSeed, as a standalone Sapling xsk can be imported via
z_importkey. However, it must have been generated from a seed itself,
and thus is more likely to be backed up elsewhere.