When passing around unsigned and signed transactions, outputs
and key images are passed along (outputs are passed along unsigned
transactions from the hot wallet to the cold wallet, key images
are passed along with signed transations from the cold wallet
to the hot wallet), to allow more user friendly syncing between
hot and cold wallets.
The vast majority of transactions will have just one tx pubkey,
but a bug with cold wallet signing caused two such keys to be
there, with the second one being the real one.
View wallets do not have the spend secret key, and are thus
unable to derive key images for incoming outputs. Moreover,
a previous patch set key images to zero as a means to mark
an output as having an unknown key image, so they could be
filled in when importing key images at a later time. That
later patch caused spurious collisions. We now use public
keys to detect duplicate outputs. Public keys obtained from
the blockchain are checked to be identical to the ones
derived locally, so can't be spoofed.
m_amount_out was sometimes getting initialized with the sum of
an transaction's outputs, and sometimes with the sum of outputs
that were not change. This caused confusion and bugs. We now
always set it to the sum of outputs. This reverts an earlier
fix for bad amounts as this used the other semantics. The wallet
data should be converted automatically in a percentage of cases
that I'm hesitant to estimate. In any case, restoring from seed
or keys or rebuilding the cache will get it right.
Compute derivation only once per tx, instead of once per output. Approx 33% faster while using 75% as much CPU on my machine. Note old functions in cryptonote_core (lookup_acc_outs and is_out_to_acc) are still used by tests.
The intended use is to export outputs from a hot wallet, which
can scan incoming transfers from the network, and import them
in the cold wallet, which can't. The cold wallet can then compute
key images for those outputs, which can then be exported with
export_key_images, etc.
Re-creating the transaction on the cold wallet was not splitting
the change, causing the transaction to be rejected by the network.
This worked on testnet since amounts do not have to be split.
Also add selected_transfers, which can now be saved since they're
size_t rather than iterators. This allows the view wallet to
properly set the sent outputs as spent and update balance.
Bump transfer file version numbers to match.
0950be9 wallet: speed up output selection, and fix bug with relatedness calculation (moneromooo-monero)
0eba133 wallet: fix mixup between mixin 2 and 4 before/after v5 (moneromooo-monero)
25% of the outputs are selected from the last 5 days (if possible),
in order to avoid the common case of sending recently received
outputs again. 25% and 5 days are subject to review later, since
it's just a wallet level change.
This was still using the old transaction creation algorithm,
coupled with a deterministic output selection scheme, which
made it ill suited to the job, since it'd loop indefinitely
in case the fee increased between the test tx and adding the
fee.
bba6af9 wallet: cold wallet transaction signing (moneromooo-monero)
9872dcb wallet: fix log confusion between bytes and kilobytes (moneromooo-monero)
d9b0bf9 cryptonote_core: make extra field removal more generic (moneromooo-monero)
98f19d4 serialization: add support for serializing std::pair and std::list (moneromooo-monero)
