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// Copyright 2024 MaidSafe.net limited.
//
// This SAFE Network Software is licensed to you under The General Public License (GPL), version 3.
// Unless required by applicable law or agreed to in writing, the SAFE Network Software distributed
// under the GPL Licence is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. Please review the Licences for the specific language governing
// permissions and limitations relating to use of the SAFE Network Software.
use crate::{
close_group_majority, driver::GetRecordCfg, GetRecordError, Network, NetworkError, Result,
};
use libp2p::kad::{Quorum, Record};
use sn_protocol::{
storage::{try_deserialize_record, RecordHeader, RecordKind, RetryStrategy, SpendAddress},
NetworkAddress, PrettyPrintRecordKey,
};
use sn_transfers::{CashNote, CashNoteRedemption, HotWallet, MainPubkey, SignedSpend, Transfer};
use std::collections::BTreeSet;
use tokio::task::JoinSet;
impl Network {
/// Gets raw spends from the Network.
/// For normal use please prefer using `get_spend` instead.
/// Double spends returned together as is, not as an error.
/// The target may have high chance not present in the network yet.
///
/// If we get a quorum error, we enable re-try
pub async fn get_raw_spends(&self, address: SpendAddress) -> Result<Vec<SignedSpend>> {
let key = NetworkAddress::from_spend_address(address).to_record_key();
let get_cfg = GetRecordCfg {
get_quorum: Quorum::Majority,
retry_strategy: None,
// This should not be set here. This function is used as a quick check to find the spends around the key during
// validation. The returned records might possibly be double spend attempt and the record will not match
// what we will have in hand.
target_record: None,
expected_holders: Default::default(),
is_register: false,
};
let record = self.get_record_from_network(key.clone(), &get_cfg).await?;
debug!(
"Got record from the network, {:?}",
PrettyPrintRecordKey::from(&record.key)
);
get_raw_signed_spends_from_record(&record)
}
/// Gets a spend from the Network.
/// We know it must be there, and has to be fetched from Quorum::All
///
/// If we get a quorum error, we increase the RetryStrategy
pub async fn get_spend(&self, address: SpendAddress) -> Result<SignedSpend> {
let key = NetworkAddress::from_spend_address(address).to_record_key();
let mut get_cfg = GetRecordCfg {
get_quorum: Quorum::All,
retry_strategy: Some(RetryStrategy::Quick),
target_record: None,
expected_holders: Default::default(),
is_register: false,
};
let record = match self.get_record_from_network(key.clone(), &get_cfg).await {
Ok(record) => record,
Err(NetworkError::GetRecordError(GetRecordError::NotEnoughCopies {
record,
expected,
got,
})) => {
// if majority holds the spend, it might be worth to be trusted.
if got >= close_group_majority() {
debug!("At least a majority nodes hold the spend {address:?}, going to trust it if can fetch with majority again.");
get_cfg.get_quorum = Quorum::Majority;
get_cfg.retry_strategy = Some(RetryStrategy::Balanced);
self.get_record_from_network(key, &get_cfg).await?
} else {
return Err(NetworkError::GetRecordError(
GetRecordError::NotEnoughCopies {
record,
expected,
got,
},
));
}
}
Err(err) => return Err(err),
};
debug!(
"Got record from the network, {:?}",
PrettyPrintRecordKey::from(&record.key)
);
get_signed_spend_from_record(&address, &record)
}
/// This function is used to receive a Transfer and turn it back into spendable CashNotes.
/// Needs Network connection.
/// Verify Transfer and rebuild spendable currency from it
/// Returns an `Error::FailedToDecypherTransfer` if the transfer cannot be decyphered
/// (This means the transfer is not for us as it was not encrypted to our key)
/// Returns an `Error::InvalidTransfer` if the transfer is not valid
/// Else returns a list of CashNotes that can be deposited to our wallet and spent
pub async fn verify_and_unpack_transfer(
&self,
transfer: &Transfer,
wallet: &HotWallet,
) -> Result<Vec<CashNote>> {
// get CashNoteRedemptions from encrypted Transfer
debug!("Decyphering Transfer");
let cashnote_redemptions = wallet.unwrap_transfer(transfer)?;
self.verify_cash_notes_redemptions(wallet.address(), &cashnote_redemptions)
.await
}
/// This function is used to receive a list of CashNoteRedemptions and turn it back into spendable CashNotes.
/// Needs Network connection.
/// Verify CashNoteRedemptions and rebuild spendable currency from them.
/// Returns an `Error::InvalidTransfer` if any CashNoteRedemption is not valid
/// Else returns a list of CashNotes that can be spent by the owner.
pub async fn verify_cash_notes_redemptions(
&self,
main_pubkey: MainPubkey,
cashnote_redemptions: &[CashNoteRedemption],
) -> Result<Vec<CashNote>> {
// get all the parent spends
debug!(
"Getting parent spends for validation from {:?}",
cashnote_redemptions.len()
);
let parent_addrs: BTreeSet<SpendAddress> = cashnote_redemptions
.iter()
.flat_map(|u| u.parent_spends.clone())
.collect();
let mut tasks = JoinSet::new();
for addr in parent_addrs.clone() {
let self_clone = self.clone();
let _ = tasks.spawn(async move { self_clone.get_spend(addr).await });
}
let mut parent_spends = BTreeSet::new();
while let Some(result) = tasks.join_next().await {
let signed_spend = result
.map_err(|e| NetworkError::FailedToGetSpend(format!("{e}")))?
.map_err(|e| NetworkError::InvalidTransfer(format!("{e}")))?;
let _ = parent_spends.insert(signed_spend.clone());
}
// get our outputs CashNotes
let our_output_cash_notes: Vec<CashNote> = cashnote_redemptions
.iter()
.map(|cnr| {
let derivation_index = cnr.derivation_index;
// assuming parent spends all exist as they were collected just above
let parent_spends: BTreeSet<SignedSpend> = cnr
.parent_spends
.iter()
.flat_map(|a| {
parent_spends
.iter()
.find(|s| &s.address() == a)
.map(|s| vec![s])
.unwrap_or_default()
})
.cloned()
.collect();
CashNote {
parent_spends: parent_spends.clone(),
main_pubkey,
derivation_index,
}
})
.collect();
// verify our output cash notes
for cash_note in our_output_cash_notes.iter() {
cash_note.verify().map_err(|e| {
NetworkError::InvalidTransfer(format!("Invalid CashNoteRedemption: {e}"))
})?;
}
Ok(our_output_cash_notes)
}
}
/// Tries to get the signed spend out of a record as is, double spends are returned together as is.
pub fn get_raw_signed_spends_from_record(record: &Record) -> Result<Vec<SignedSpend>> {
let header = RecordHeader::from_record(record)?;
if let RecordKind::Spend = header.kind {
let spends = try_deserialize_record::<Vec<SignedSpend>>(record)?;
Ok(spends)
} else {
warn!(
"RecordKind mismatch while trying to retrieve spends from record {:?}",
PrettyPrintRecordKey::from(&record.key)
);
Err(NetworkError::RecordKindMismatch(RecordKind::Spend))
}
}
/// Get the signed spend out of a record.
/// Double spends are returned as an error
pub fn get_signed_spend_from_record(
address: &SpendAddress,
record: &Record,
) -> Result<SignedSpend> {
let spends = get_raw_signed_spends_from_record(record)?;
match spends.as_slice() {
[] => {
error!("Found no spend for {address:?}");
Err(NetworkError::NoSpendFoundInsideRecord(*address))
}
[one] => {
debug!("Spend get for address: {address:?} successful");
Ok(one.clone())
}
_double_spends => {
warn!(
"Found double spend(s) of len {} for {address:?}",
spends.len()
);
Err(NetworkError::DoubleSpendAttempt(spends))
}
}
}