Fix https://github.com/serai-dex/serai/issues/106

coins/monero/src/wallet/mod.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::{HashSet, HashMap};
 
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
@@ -124,19 +124,25 @@ impl ViewPair {
 pub struct Scanner {
   pair: ViewPair,
   network: Network,
-  guaranteed: bool,
   pub(crate) subaddresses: HashMap<CompressedEdwardsY, (u32, u32)>,
+  pub(crate) burning_bug: Option<HashSet<CompressedEdwardsY>>,
 }
 
 impl Zeroize for Scanner {
   fn zeroize(&mut self) {
     self.pair.zeroize();
     self.network.zeroize();
-    self.guaranteed.zeroize();
+
+    // These may not be effective, unfortunately
     for (mut key, mut value) in self.subaddresses.drain() {
       key.zeroize();
       value.zeroize();
     }
+    if let Some(ref mut burning_bug) = self.burning_bug.take() {
+      for mut output in burning_bug.drain() {
+        output.zeroize();
+      }
+    }
   }
 }
 
@@ -149,17 +155,23 @@ impl Drop for Scanner {
 impl ZeroizeOnDrop for Scanner {}
 
 impl Scanner {
-  pub fn from_view(pair: ViewPair, network: Network, guaranteed: bool) -> Scanner {
+  // For burning bug immune addresses (Featured Address w/ the Guaranteed feature), pass None
+  // For traditional Monero address, provide a HashSet of all historically scanned output keys
+  pub fn from_view(
+    pair: ViewPair,
+    network: Network,
+    burning_bug: Option<HashSet<CompressedEdwardsY>>,
+  ) -> Scanner {
     let mut subaddresses = HashMap::new();
     subaddresses.insert(pair.spend.compress(), (0, 0));
-    Scanner { pair, network, guaranteed, subaddresses }
+    Scanner { pair, network, subaddresses, burning_bug }
   }
 
   pub fn address(&self) -> Address {
     Address::new(
       AddressMeta {
         network: self.network,
-        kind: if self.guaranteed {
+        kind: if self.burning_bug.is_none() {
           AddressType::Featured(false, None, true)
         } else {
           AddressType::Standard
@@ -181,7 +193,7 @@ impl Scanner {
     Address::new(
       AddressMeta {
         network: self.network,
-        kind: if self.guaranteed {
+        kind: if self.burning_bug.is_none() {
           AddressType::Featured(true, None, true)
         } else {
           AddressType::Subaddress

coins/monero/src/wallet/scan.rs

@@ -95,7 +95,7 @@ impl SpendableOutput {
 }
 
 impl Scanner {
-  pub fn scan(&self, tx: &Transaction) -> Timelocked {
+  pub fn scan(&mut self, tx: &Transaction) -> Timelocked {
     let extra = Extra::deserialize(&mut Cursor::new(&tx.prefix.extra));
     let keys;
     let extra = if let Ok(extra) = extra {
@@ -108,9 +108,17 @@ impl Scanner {
 
     let mut res = vec![];
     for (o, output) in tx.prefix.outputs.iter().enumerate() {
+      // https://github.com/serai-dex/serai/issues/102
+      let output_key_compressed = output.key.compress();
+      if let Some(burning_bug) = self.burning_bug.as_ref() {
+        if burning_bug.contains(&output_key_compressed) {
+          continue;
+        }
+      }
+
       for key in &keys {
         let (view_tag, key_offset, payment_id_xor) = shared_key(
-          if self.guaranteed { Some(uniqueness(&tx.prefix.inputs)) } else { None },
+          if self.burning_bug.is_none() { Some(uniqueness(&tx.prefix.inputs)) } else { None },
           &self.pair.view,
           key,
           o,
@@ -173,6 +181,10 @@ impl Scanner {
             subaddress: (0, 0),
             payment_id,
           });
+
+          if let Some(burning_bug) = self.burning_bug.as_mut() {
+            burning_bug.insert(output_key_compressed);
+          }
         }
         // Break to prevent public keys from being included multiple times, triggering multiple
         // inclusions of the same output

coins/monero/tests/send.rs

@@ -1,4 +1,4 @@
-use std::sync::Mutex;
+use std::{sync::Mutex, collections::HashSet};
 #[cfg(feature = "multisig")]
 use std::collections::HashMap;
 
@@ -75,7 +75,7 @@ async fn send_core(test: usize, multisig: bool) {
   }
 
   let view_pair = ViewPair::new(spend_pub, view);
-  let scanner = Scanner::from_view(view_pair, Network::Mainnet, false);
+  let mut scanner = Scanner::from_view(view_pair, Network::Mainnet, Some(HashSet::new()));
   let addr = scanner.address();
 
   let fee = rpc.get_fee().await.unwrap();

processor/src/coin/monero.rs

@@ -72,7 +72,7 @@ impl Monero {
   }
 
   fn scanner(&self, spend: dfg::EdwardsPoint) -> Scanner {
-    Scanner::from_view(ViewPair::new(spend.0, self.view), Network::Mainnet, true)
+    Scanner::from_view(ViewPair::new(spend.0, self.view), Network::Mainnet, None)
   }
 
   #[cfg(test)]
@@ -81,7 +81,7 @@ impl Monero {
     Scanner::from_view(
       ViewPair::new(*dfg::EdwardsPoint::generator(), Scalar::one()),
       Network::Mainnet,
-      false,
+      Some(std::collections::HashSet::new()),
     )
   }
 
@@ -129,7 +129,7 @@ impl Coin for Monero {
   }
 
   async fn get_outputs(&self, block: &Self::Block, key: dfg::EdwardsPoint) -> Vec<Self::Output> {
-    let scanner = self.scanner(key);
+    let mut scanner = self.scanner(key);
     block.iter().flat_map(|tx| scanner.scan(tx).not_locked()).map(Output::from).collect()
   }