Add ScannableBlock abstraction in the RPC

Makes scanning synchronous and only error upon a malicious node/unplanned for
hard fork.

Cargo.lock

@@ -4949,7 +4949,6 @@ dependencies = [
 name = "monero-rpc"
 version = "0.1.0"
 dependencies = [
- "async-trait",
  "curve25519-dalek",
  "hex",
  "monero-address",
@@ -5013,7 +5012,6 @@ dependencies = [
 name = "monero-simple-request-rpc"
 version = "0.1.0"
 dependencies = [
- "async-trait",
  "digest_auth",
  "hex",
  "monero-address",

networks/monero/rpc/Cargo.toml

@@ -18,7 +18,6 @@ workspace = true
 [dependencies]
 std-shims = { path = "../../../common/std-shims", version = "^0.1.1", default-features = false }
 
-async-trait = { version = "0.1", default-features = false }
 thiserror = { version = "1", default-features = false, optional = true }
 
 zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }

networks/monero/rpc/simple-request/Cargo.toml

@@ -16,8 +16,6 @@ rustdoc-args = ["--cfg", "docsrs"]
 workspace = true
 
 [dependencies]
-async-trait = { version = "0.1", default-features = false }
-
 hex = { version = "0.4", default-features = false, features = ["alloc"] }
 digest_auth = { version = "0.3", default-features = false }
 simple-request = { path = "../../../../common/request", version = "0.1", default-features = false, features = ["tls"] }

networks/monero/rpc/simple-request/src/lib.rs

@@ -2,10 +2,9 @@
 #![doc = include_str!("../README.md")]
 #![deny(missing_docs)]
 
+use core::future::Future;
 use std::{sync::Arc, io::Read, time::Duration};
 
-use async_trait::async_trait;
-
 use tokio::sync::Mutex;
 
 use digest_auth::{WwwAuthenticateHeader, AuthContext};
@@ -280,11 +279,16 @@ impl SimpleRequestRpc {
   }
 }
 
-#[async_trait]
 impl Rpc for SimpleRequestRpc {
-  async fn post(&self, route: &str, body: Vec<u8>) -> Result<Vec<u8>, RpcError> {
+  fn post(
+    &self,
+    route: &str,
+    body: Vec<u8>,
+  ) -> impl Send + Future<Output = Result<Vec<u8>, RpcError>> {
+    async move {
       tokio::time::timeout(self.request_timeout, self.inner_post(route, body))
         .await
         .map_err(|e| RpcError::ConnectionError(format!("{e:?}")))?
     }
+  }
 }

networks/monero/rpc/src/lib.rs

@@ -4,11 +4,12 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use core::{
+  future::Future,
   fmt::Debug,
   ops::{Bound, RangeBounds},
 };
 use std_shims::{
-  alloc::{boxed::Box, format},
+  alloc::format,
   vec,
   vec::Vec,
   io,
@@ -17,8 +18,6 @@ use std_shims::{
 
 use zeroize::Zeroize;
 
-use async_trait::async_trait;
-
 use curve25519_dalek::edwards::{CompressedEdwardsY, EdwardsPoint};
 
 use serde::{Serialize, Deserialize, de::DeserializeOwned};
@@ -74,6 +73,19 @@ pub enum RpcError {
   InvalidPriority,
 }
 
+/// A block which is able to be scanned.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ScannableBlock {
+  /// The block which is being scanned.
+  pub block: Block,
+  /// The non-miner transactions within this block.
+  pub transactions: Vec<Transaction<Pruned>>,
+  /// The output index for the first RingCT output within this block.
+  ///
+  /// None if there are no RingCT outputs within this block, Some otherwise.
+  pub output_index_for_first_ringct_output: Option<u64>,
+}
+
 /// A struct containing a fee rate.
 ///
 /// The fee rate is defined as a per-weight cost, along with a mask for rounding purposes.
@@ -237,22 +249,26 @@ fn rpc_point(point: &str) -> Result<EdwardsPoint, RpcError> {
 /// While no implementors are directly provided, [monero-simple-request-rpc](
 ///   https://github.com/serai-dex/serai/tree/develop/networks/monero/rpc/simple-request
 /// ) is recommended.
-#[async_trait]
 pub trait Rpc: Sync + Clone + Debug {
   /// Perform a POST request to the specified route with the specified body.
   ///
   /// The implementor is left to handle anything such as authentication.
-  async fn post(&self, route: &str, body: Vec<u8>) -> Result<Vec<u8>, RpcError>;
+  fn post(
+    &self,
+    route: &str,
+    body: Vec<u8>,
+  ) -> impl Send + Future<Output = Result<Vec<u8>, RpcError>>;
 
   /// Perform a RPC call to the specified route with the provided parameters.
   ///
   /// This is NOT a JSON-RPC call. They use a route of "json_rpc" and are available via
   /// `json_rpc_call`.
-  async fn rpc_call<Params: Send + Serialize + Debug, Response: DeserializeOwned + Debug>(
+  fn rpc_call<Params: Send + Serialize + Debug, Response: DeserializeOwned + Debug>(
     &self,
     route: &str,
     params: Option<Params>,
-  ) -> Result<Response, RpcError> {
+  ) -> impl Send + Future<Output = Result<Response, RpcError>> {
+    async move {
       let res = self
         .post(
           route,
@@ -268,29 +284,37 @@ pub trait Rpc: Sync + Clone + Debug {
       serde_json::from_str(res_str)
         .map_err(|_| RpcError::InvalidNode(format!("response wasn't the expected json: {res_str}")))
     }
+  }
 
   /// Perform a JSON-RPC call with the specified method with the provided parameters.
-  async fn json_rpc_call<Response: DeserializeOwned + Debug>(
+  fn json_rpc_call<Response: DeserializeOwned + Debug>(
     &self,
     method: &str,
     params: Option<Value>,
-  ) -> Result<Response, RpcError> {
+  ) -> impl Send + Future<Output = Result<Response, RpcError>> {
+    async move {
       let mut req = json!({ "method": method });
       if let Some(params) = params {
         req.as_object_mut().unwrap().insert("params".into(), params);
       }
       Ok(self.rpc_call::<_, JsonRpcResponse<Response>>("json_rpc", Some(req)).await?.result)
     }
+  }
 
   /// Perform a binary call to the specified route with the provided parameters.
-  async fn bin_call(&self, route: &str, params: Vec<u8>) -> Result<Vec<u8>, RpcError> {
+  fn bin_call(
-    self.post(route, params).await
+    &self,
+    route: &str,
+    params: Vec<u8>,
+  ) -> impl Send + Future<Output = Result<Vec<u8>, RpcError>> {
+    async move { self.post(route, params).await }
   }
 
   /// Get the active blockchain protocol version.
   ///
   /// This is specifically the major version within the most recent block header.
-  async fn get_hardfork_version(&self) -> Result<u8, RpcError> {
+  fn get_hardfork_version(&self) -> impl Send + Future<Output = Result<u8, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct HeaderResponse {
         major_version: u8,
@@ -309,12 +333,14 @@ pub trait Rpc: Sync + Clone + Debug {
           .major_version,
       )
     }
+  }
 
   /// Get the height of the Monero blockchain.
   ///
   /// The height is defined as the amount of blocks on the blockchain. For a blockchain with only
   /// its genesis block, the height will be 1.
-  async fn get_height(&self) -> Result<usize, RpcError> {
+  fn get_height(&self) -> impl Send + Future<Output = Result<usize, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct HeightResponse {
         height: usize,
@@ -325,12 +351,17 @@ pub trait Rpc: Sync + Clone + Debug {
       }
       Ok(res)
     }
+  }
 
   /// Get the specified transactions.
   ///
   /// The received transactions will be hashed in order to verify the correct transactions were
   /// returned.
-  async fn get_transactions(&self, hashes: &[[u8; 32]]) -> Result<Vec<Transaction>, RpcError> {
+  fn get_transactions(
+    &self,
+    hashes: &[[u8; 32]],
+  ) -> impl Send + Future<Output = Result<Vec<Transaction>, RpcError>> {
+    async move {
       if hashes.is_empty() {
         return Ok(vec![]);
       }
@@ -396,12 +427,14 @@ pub trait Rpc: Sync + Clone + Debug {
         })
         .collect()
     }
+  }
 
   /// Get the specified transactions in their pruned format.
-  async fn get_pruned_transactions(
+  fn get_pruned_transactions(
     &self,
     hashes: &[[u8; 32]],
-  ) -> Result<Vec<Transaction<Pruned>>, RpcError> {
+  ) -> impl Send + Future<Output = Result<Vec<Transaction<Pruned>>, RpcError>> {
+    async move {
       if hashes.is_empty() {
         return Ok(vec![]);
       }
@@ -447,25 +480,36 @@ pub trait Rpc: Sync + Clone + Debug {
         })
         .collect()
     }
+  }
 
   /// Get the specified transaction.
   ///
   /// The received transaction will be hashed in order to verify the correct transaction was
   /// returned.
-  async fn get_transaction(&self, tx: [u8; 32]) -> Result<Transaction, RpcError> {
+  fn get_transaction(
-    self.get_transactions(&[tx]).await.map(|mut txs| txs.swap_remove(0))
+    &self,
+    tx: [u8; 32],
+  ) -> impl Send + Future<Output = Result<Transaction, RpcError>> {
+    async move { self.get_transactions(&[tx]).await.map(|mut txs| txs.swap_remove(0)) }
   }
 
   /// Get the specified transaction in its pruned format.
-  async fn get_pruned_transaction(&self, tx: [u8; 32]) -> Result<Transaction<Pruned>, RpcError> {
+  fn get_pruned_transaction(
-    self.get_pruned_transactions(&[tx]).await.map(|mut txs| txs.swap_remove(0))
+    &self,
+    tx: [u8; 32],
+  ) -> impl Send + Future<Output = Result<Transaction<Pruned>, RpcError>> {
+    async move { self.get_pruned_transactions(&[tx]).await.map(|mut txs| txs.swap_remove(0)) }
   }
 
   /// Get the hash of a block from the node.
   ///
   /// `number` is the block's zero-indexed position on the blockchain (`0` for the genesis block,
   /// `height - 1` for the latest block).
-  async fn get_block_hash(&self, number: usize) -> Result<[u8; 32], RpcError> {
+  fn get_block_hash(
+    &self,
+    number: usize,
+  ) -> impl Send + Future<Output = Result<[u8; 32], RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct BlockHeaderResponse {
         hash: String,
@@ -479,11 +523,13 @@ pub trait Rpc: Sync + Clone + Debug {
         self.json_rpc_call("get_block_header_by_height", Some(json!({ "height": number }))).await?;
       hash_hex(&header.block_header.hash)
     }
+  }
 
   /// Get a block from the node by its hash.
   ///
   /// The received block will be hashed in order to verify the correct block was returned.
-  async fn get_block(&self, hash: [u8; 32]) -> Result<Block, RpcError> {
+  fn get_block(&self, hash: [u8; 32]) -> impl Send + Future<Output = Result<Block, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct BlockResponse {
         blob: String,
@@ -499,12 +545,17 @@ pub trait Rpc: Sync + Clone + Debug {
       }
       Ok(block)
     }
+  }
 
   /// Get a block from the node by its number.
   ///
   /// `number` is the block's zero-indexed position on the blockchain (`0` for the genesis block,
   /// `height - 1` for the latest block).
-  async fn get_block_by_number(&self, number: usize) -> Result<Block, RpcError> {
+  fn get_block_by_number(
+    &self,
+    number: usize,
+  ) -> impl Send + Future<Output = Result<Block, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct BlockResponse {
         blob: String,
@@ -530,13 +581,107 @@ pub trait Rpc: Sync + Clone + Debug {
         )),
       }
     }
+  }
+
+  /// Get a block's scannable form.
+  fn get_scannable_block(
+    &self,
+    block: Block,
+  ) -> impl Send + Future<Output = Result<ScannableBlock, RpcError>> {
+    async move {
+      let transactions = self.get_pruned_transactions(&block.transactions).await?;
+
+      /*
+        Requesting the output index for each output we sucessfully scan would cause a loss of
+        privacy. We could instead request the output indexes for all outputs we scan, yet this
+        would notably increase the amount of RPC calls we make.
+
+        We solve this by requesting the output index for the first RingCT output in the block, which
+        should be within the miner transaction. Then, as we scan transactions, we update the output
+        index ourselves.
+
+        Please note we only will scan RingCT outputs so we only need to track the RingCT output
+        index. This decision was made due to spending CN outputs potentially having burdensome
+        requirements (the need to make a v1 TX due to insufficient decoys).
+
+        We bound ourselves to only scanning RingCT outputs by only scanning v2 transactions. This is
+        safe and correct since:
+
+        1) v1 transactions cannot create RingCT outputs.
+
+           https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+             /src/cryptonote_basic/cryptonote_format_utils.cpp#L866-L869
+
+        2) v2 miner transactions implicitly create RingCT outputs.
+
+           https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+             /src/blockchain_db/blockchain_db.cpp#L232-L241
+
+        3) v2 transactions must create RingCT outputs.
+
+           https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c45
+             /src/cryptonote_core/blockchain.cpp#L3055-L3065
+
+           That does bound on the hard fork version being >= 3, yet all v2 TXs have a hard fork
+           version > 3.
+
+           https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+             /src/cryptonote_core/blockchain.cpp#L3417
+      */
+
+      // Get the index for the first output
+      let mut output_index_for_first_ringct_output = None;
+      let miner_tx_hash = block.miner_transaction.hash();
+      let miner_tx = Transaction::<Pruned>::from(block.miner_transaction.clone());
+      for (hash, tx) in core::iter::once((&miner_tx_hash, &miner_tx))
+        .chain(block.transactions.iter().zip(&transactions))
+      {
+        // If this isn't a RingCT output, or there are no outputs, move to the next TX
+        if (!matches!(tx, Transaction::V2 { .. })) || tx.prefix().outputs.is_empty() {
+          continue;
+        }
+
+        let index = *self.get_o_indexes(*hash).await?.first().ok_or_else(|| {
+          RpcError::InvalidNode(
+            "requested output indexes for a TX with outputs and got none".to_string(),
+          )
+        })?;
+        output_index_for_first_ringct_output = Some(index);
+        break;
+      }
+
+      Ok(ScannableBlock { block, transactions, output_index_for_first_ringct_output })
+    }
+  }
+
+  /// Get a block's scannable form by its hash.
+  // TODO: get_blocks.bin
+  fn get_scannable_block_by_hash(
+    &self,
+    hash: [u8; 32],
+  ) -> impl Send + Future<Output = Result<ScannableBlock, RpcError>> {
+    async move { self.get_scannable_block(self.get_block(hash).await?).await }
+  }
+
+  /// Get a block's scannable form by its number.
+  // TODO: get_blocks_by_height.bin
+  fn get_scannable_block_by_number(
+    &self,
+    number: usize,
+  ) -> impl Send + Future<Output = Result<ScannableBlock, RpcError>> {
+    async move { self.get_scannable_block(self.get_block_by_number(number).await?).await }
+  }
 
   /// Get the currently estimated fee rate from the node.
   ///
   /// This may be manipulated to unsafe levels and MUST be sanity checked.
   ///
   /// This MUST NOT be expected to be deterministic in any way.
-  async fn get_fee_rate(&self, priority: FeePriority) -> Result<FeeRate, RpcError> {
+  fn get_fee_rate(
+    &self,
+    priority: FeePriority,
+  ) -> impl Send + Future<Output = Result<FeeRate, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct FeeResponse {
         status: String,
@@ -576,8 +721,11 @@ pub trait Rpc: Sync + Clone + Debug {
         //   src/wallet/wallet2.cpp#L7569-L7584
         // https://github.com/monero-project/monero/blob/94e67bf96bbc010241f29ada6abc89f49a81759c/
         //   src/wallet/wallet2.cpp#L7660-L7661
-      let priority_idx =
+        let priority_idx = usize::try_from(if priority.fee_priority() == 0 {
-        usize::try_from(if priority.fee_priority() == 0 { 1 } else { priority.fee_priority() - 1 })
+          1
+        } else {
+          priority.fee_priority() - 1
+        })
         .map_err(|_| RpcError::InvalidPriority)?;
         let multipliers = [1, 5, 25, 1000];
         if priority_idx >= multipliers.len() {
@@ -589,9 +737,14 @@ pub trait Rpc: Sync + Clone + Debug {
         FeeRate::new(res.fee * fee_multiplier, res.quantization_mask)
       }
     }
+  }
 
   /// Publish a transaction.
-  async fn publish_transaction(&self, tx: &Transaction) -> Result<(), RpcError> {
+  fn publish_transaction(
+    &self,
+    tx: &Transaction,
+  ) -> impl Send + Future<Output = Result<(), RpcError>> {
+    async move {
       #[allow(dead_code)]
       #[derive(Debug, Deserialize)]
       struct SendRawResponse {
@@ -621,15 +774,17 @@ pub trait Rpc: Sync + Clone + Debug {
 
       Ok(())
     }
+  }
 
   /// Generate blocks, with the specified address receiving the block reward.
   ///
   /// Returns the hashes of the generated blocks and the last block's number.
-  async fn generate_blocks<const ADDR_BYTES: u128>(
+  fn generate_blocks<const ADDR_BYTES: u128>(
     &self,
     address: &Address<ADDR_BYTES>,
     block_count: usize,
-  ) -> Result<(Vec<[u8; 32]>, usize), RpcError> {
+  ) -> impl Send + Future<Output = Result<(Vec<[u8; 32]>, usize), RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct BlocksResponse {
         blocks: Vec<String>,
@@ -652,11 +807,16 @@ pub trait Rpc: Sync + Clone + Debug {
       }
       Ok((blocks, res.height))
     }
+  }
 
   /// Get the output indexes of the specified transaction.
-  async fn get_o_indexes(&self, hash: [u8; 32]) -> Result<Vec<u64>, RpcError> {
+  fn get_o_indexes(
-    // Given the immaturity of Rust epee libraries, this is a homegrown one which is only validated
+    &self,
-    // to work against this specific function
+    hash: [u8; 32],
+  ) -> impl Send + Future<Output = Result<Vec<u64>, RpcError>> {
+    async move {
+      // Given the immaturity of Rust epee libraries, this is a homegrown one which is only
+      // validated to work against this specific function
 
       // Header for EPEE, an 8-byte magic and a version
       const EPEE_HEADER: &[u8] = b"\x01\x11\x01\x01\x01\x01\x02\x01\x01";
@@ -735,7 +895,9 @@ pub trait Rpc: Sync + Clone + Debug {
                 // claim this to be a complete deserialization function
                 // To ensure it works for this specific use case, it's best to ensure it's limited
                 // to this specific use case (ensuring we have less variables to deal with)
-              _ => Err(io::Error::other(format!("unrecognized field in get_o_indexes: {name:?}")))?,
+                _ => {
+                  Err(io::Error::other(format!("unrecognized field in get_o_indexes: {name:?}")))?
+                }
               };
               if (expected_type != kind) || (expected_array_flag != has_array_flag) {
                 let fmt_array_bool = |array_bool| if array_bool { "array" } else { "not array" };
@@ -833,6 +995,7 @@ pub trait Rpc: Sync + Clone + Debug {
       })()
       .map_err(|e| RpcError::InvalidNode(format!("invalid binary response: {e:?}")))
     }
+  }
 }
 
 /// A trait for any object which can be used to select RingCT decoys.
@@ -840,25 +1003,29 @@ pub trait Rpc: Sync + Clone + Debug {
 /// An implementation is provided for any satisfier of `Rpc`. It is not recommended to use an `Rpc`
 /// object to satisfy this. This should be satisfied by a local store of the output distribution,
 /// both for performance and to prevent potential attacks a remote node can perform.
-#[async_trait]
 pub trait DecoyRpc: Sync + Clone + Debug {
   /// Get the height the output distribution ends at.
   ///
   /// This is equivalent to the hight of the blockchain it's for. This is intended to be cheaper
   /// than fetching the entire output distribution.
-  async fn get_output_distribution_end_height(&self) -> Result<usize, RpcError>;
+  fn get_output_distribution_end_height(
+    &self,
+  ) -> impl Send + Future<Output = Result<usize, RpcError>>;
 
   /// Get the RingCT (zero-amount) output distribution.
   ///
   /// `range` is in terms of block numbers. The result may be smaller than the requested range if
   /// the range starts before RingCT outputs were created on-chain.
-  async fn get_output_distribution(
+  fn get_output_distribution(
     &self,
     range: impl Send + RangeBounds<usize>,
-  ) -> Result<Vec<u64>, RpcError>;
+  ) -> impl Send + Future<Output = Result<Vec<u64>, RpcError>>;
 
   /// Get the specified outputs from the RingCT (zero-amount) pool.
-  async fn get_outs(&self, indexes: &[u64]) -> Result<Vec<OutputInformation>, RpcError>;
+  fn get_outs(
+    &self,
+    indexes: &[u64],
+  ) -> impl Send + Future<Output = Result<Vec<OutputInformation>, RpcError>>;
 
   /// Get the specified outputs from the RingCT (zero-amount) pool, but only return them if their
   /// timelock has been satisfied.
@@ -871,24 +1038,26 @@ pub trait DecoyRpc: Sync + Clone + Debug {
   /// used, yet the transaction's timelock is checked to be unlocked at the specified `height`.
   /// This offers a deterministic decoy selection, yet is fingerprintable as time-based timelocks
   /// aren't evaluated (and considered locked, preventing their selection).
-  async fn get_unlocked_outputs(
+  fn get_unlocked_outputs(
     &self,
     indexes: &[u64],
     height: usize,
     fingerprintable_deterministic: bool,
-  ) -> Result<Vec<Option<[EdwardsPoint; 2]>>, RpcError>;
+  ) -> impl Send + Future<Output = Result<Vec<Option<[EdwardsPoint; 2]>>, RpcError>>;
 }
 
-#[async_trait]
 impl<R: Rpc> DecoyRpc for R {
-  async fn get_output_distribution_end_height(&self) -> Result<usize, RpcError> {
+  fn get_output_distribution_end_height(
-    <Self as Rpc>::get_height(self).await
+    &self,
+  ) -> impl Send + Future<Output = Result<usize, RpcError>> {
+    async move { <Self as Rpc>::get_height(self).await }
   }
 
-  async fn get_output_distribution(
+  fn get_output_distribution(
     &self,
     range: impl Send + RangeBounds<usize>,
-  ) -> Result<Vec<u64>, RpcError> {
+  ) -> impl Send + Future<Output = Result<Vec<u64>, RpcError>> {
+    async move {
       #[derive(Default, Debug, Deserialize)]
       struct Distribution {
         distribution: Vec<u64>,
@@ -904,9 +1073,9 @@ impl<R: Rpc> DecoyRpc for R {
 
       let from = match range.start_bound() {
         Bound::Included(from) => *from,
-      Bound::Excluded(from) => from
+        Bound::Excluded(from) => from.checked_add(1).ok_or_else(|| {
-        .checked_add(1)
+          RpcError::InternalError("range's from wasn't representable".to_string())
-        .ok_or_else(|| RpcError::InternalError("range's from wasn't representable".to_string()))?,
+        })?,
         Bound::Unbounded => 0,
       };
       let to = match range.end_bound() {
@@ -947,8 +1116,8 @@ impl<R: Rpc> DecoyRpc for R {
       let Distribution { start_height, mut distribution } = core::mem::take(&mut distributions[0]);
       // start_height is also actually a block number, and it should be at least `from`
       // It may be after depending on when these outputs first appeared on the blockchain
-    // Unfortunately, we can't validate without a binary search to find the RingCT activation block
+      // Unfortunately, we can't validate without a binary search to find the RingCT activation
-    // and an iterative search from there, so we solely sanity check it
+      // block and an iterative search from there, so we solely sanity check it
       if start_height < from {
         Err(RpcError::InvalidNode(format!(
           "requested distribution from {from} and got from {start_height}"
@@ -971,14 +1140,20 @@ impl<R: Rpc> DecoyRpc for R {
         )))?;
       }
       // Requesting to = 0 returns the distribution for the entire chain
-    // We work-around this by requesting 0, 1 (yielding two blocks), then popping the second block
+      // We work around this by requesting 0, 1 (yielding two blocks), then popping the second
+      // block
       if zero_zero_case {
         distribution.pop();
       }
       Ok(distribution)
     }
+  }
 
-  async fn get_outs(&self, indexes: &[u64]) -> Result<Vec<OutputInformation>, RpcError> {
+  fn get_outs(
+    &self,
+    indexes: &[u64],
+  ) -> impl Send + Future<Output = Result<Vec<OutputInformation>, RpcError>> {
+    async move {
       #[derive(Debug, Deserialize)]
       struct OutputResponse {
         height: usize,
@@ -1040,13 +1215,15 @@ impl<R: Rpc> DecoyRpc for R {
 
       Ok(res)
     }
+  }
 
-  async fn get_unlocked_outputs(
+  fn get_unlocked_outputs(
     &self,
     indexes: &[u64],
     height: usize,
     fingerprintable_deterministic: bool,
-  ) -> Result<Vec<Option<[EdwardsPoint; 2]>>, RpcError> {
+  ) -> impl Send + Future<Output = Result<Vec<Option<[EdwardsPoint; 2]>>, RpcError>> {
+    async move {
       let outs = self.get_outs(indexes).await?;
 
       // Only need to fetch txs to do deterministic check on timelock
@@ -1061,8 +1238,8 @@ impl<R: Rpc> DecoyRpc for R {
         .iter()
         .enumerate()
         .map(|(i, out)| {
-        // Allow keys to be invalid, though if they are, return None to trigger selection of a new
+          // Allow keys to be invalid, though if they are, return None to trigger selection of a
-        // decoy
+          // new decoy
           // Only valid keys can be used in CLSAG proofs, hence the need for re-selection, yet
           // invalid keys may honestly exist on the blockchain
           let Some(key) = out.key.decompress() else {
@@ -1071,11 +1248,13 @@ impl<R: Rpc> DecoyRpc for R {
           Ok(Some([key, out.commitment]).filter(|_| {
             if fingerprintable_deterministic {
               // https://github.com/monero-project/monero/blob
-            //   /cc73fe71162d564ffda8e549b79a350bca53c454/src/cryptonote_core/blockchain.cpp#L90
+              //   /cc73fe71162d564ffda8e549b79a350bca53c454/src/cryptonote_core
+              //   /blockchain.cpp#L90
               const ACCEPTED_TIMELOCK_DELTA: usize = 1;
 
               // https://github.com/monero-project/monero/blob
-            //   /cc73fe71162d564ffda8e549b79a350bca53c454/src/cryptonote_core/blockchain.cpp#L3836
+              //   /cc73fe71162d564ffda8e549b79a350bca53c454/src/cryptonote_core
+              //   /blockchain.cpp#L3836
               ((out.height + DEFAULT_LOCK_WINDOW) <= height) &&
                 (Timelock::Block(height - 1 + ACCEPTED_TIMELOCK_DELTA) >=
                   txs[i].prefix().additional_timelock)
@@ -1086,4 +1265,5 @@ impl<R: Rpc> DecoyRpc for R {
         })
         .collect()
     }
+  }
 }

networks/monero/wallet/Cargo.toml

@@ -11,6 +11,10 @@ rust-version = "1.80"
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
+rust-version = "1.80"
+
+[package.metadata.cargo-machete]
+ignored = ["monero-clsag"]
 
 [lints]
 workspace = true

networks/monero/wallet/src/lib.rs

@@ -23,7 +23,7 @@ pub use monero_rpc as rpc;
 pub use monero_address as address;
 
 mod view_pair;
-pub use view_pair::{ViewPair, GuaranteedViewPair};
+pub use view_pair::{ViewPairError, ViewPair, GuaranteedViewPair};
 
 /// Structures and functionality for working with transactions' extra fields.
 pub mod extra;
@@ -33,7 +33,7 @@ pub(crate) mod output;
 pub use output::WalletOutput;
 
 mod scan;
-pub use scan::{Scanner, GuaranteedScanner};
+pub use scan::{ScanError, Scanner, GuaranteedScanner};
 
 mod decoys;
 pub use decoys::OutputWithDecoys;

networks/monero/wallet/src/scan.rs

@@ -1,16 +1,15 @@
 use core::ops::Deref;
-use std_shims::{alloc::format, vec, vec::Vec, string::ToString, collections::HashMap};
+use std_shims::{vec, vec::Vec, collections::HashMap};
 
 use zeroize::{Zeroize, ZeroizeOnDrop, Zeroizing};
 
 use curve25519_dalek::{constants::ED25519_BASEPOINT_TABLE, edwards::CompressedEdwardsY};
 
-use monero_rpc::{RpcError, Rpc};
+use monero_rpc::ScannableBlock;
 use monero_serai::{
   io::*,
   primitives::Commitment,
   transaction::{Timelock, Pruned, Transaction},
-  block::Block,
 };
 use crate::{
   address::SubaddressIndex, ViewPair, GuaranteedViewPair, output::*, PaymentId, Extra,
@@ -67,6 +66,18 @@ impl Timelocked {
   }
 }
 
+/// Errors when scanning a block.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+#[cfg_attr(feature = "std", derive(thiserror::Error))]
+pub enum ScanError {
+  /// The block was for an unsupported protocol version.
+  #[cfg_attr(feature = "std", error("unsupported protocol version ({0})"))]
+  UnsupportedProtocol(u8),
+  /// The ScannableBlock was invalid.
+  #[cfg_attr(feature = "std", error("invalid scannable block ({0})"))]
+  InvalidScannableBlock(&'static str),
+}
+
 #[derive(Clone)]
 struct InternalScanner {
   pair: ViewPair,
@@ -107,10 +118,10 @@ impl InternalScanner {
 
   fn scan_transaction(
     &self,
-    tx_start_index_on_blockchain: u64,
+    output_index_for_first_ringct_output: u64,
     tx_hash: [u8; 32],
     tx: &Transaction<Pruned>,
-  ) -> Result<Timelocked, RpcError> {
+  ) -> Result<Timelocked, ScanError> {
     // Only scan TXs creating RingCT outputs
     // For the full details on why this check is equivalent, please see the documentation in `scan`
     if tx.version() != 2 {
@@ -197,14 +208,14 @@ impl InternalScanner {
         } else {
           let Transaction::V2 { proofs: Some(ref proofs), .. } = &tx else {
             // Invalid transaction, as of consensus rules at the time of writing this code
-            Err(RpcError::InvalidNode("non-miner v2 transaction without RCT proofs".to_string()))?
+            Err(ScanError::InvalidScannableBlock("non-miner v2 transaction without RCT proofs"))?
           };
 
           commitment = match proofs.base.encrypted_amounts.get(o) {
             Some(amount) => output_derivations.decrypt(amount),
             // Invalid transaction, as of consensus rules at the time of writing this code
-            None => Err(RpcError::InvalidNode(
+            None => Err(ScanError::InvalidScannableBlock(
-              "RCT proofs without an encrypted amount per output".to_string(),
+              "RCT proofs without an encrypted amount per output",
             ))?,
           };
 
@@ -223,7 +234,7 @@ impl InternalScanner {
             index_in_transaction: o.try_into().unwrap(),
           },
           relative_id: RelativeId {
-            index_on_blockchain: tx_start_index_on_blockchain + u64::try_from(o).unwrap(),
+            index_on_blockchain: output_index_for_first_ringct_output + u64::try_from(o).unwrap(),
           },
           data: OutputData { key: output_key, key_offset, commitment },
           metadata: Metadata {
@@ -243,12 +254,22 @@ impl InternalScanner {
     Ok(Timelocked(res))
   }
 
-  async fn scan(&mut self, rpc: &impl Rpc, block: &Block) -> Result<Timelocked, RpcError> {
+  fn scan(&mut self, block: ScannableBlock) -> Result<Timelocked, ScanError> {
+    // This is the output index for the first RingCT output within the block
+    // We mutate it to be the output index for the first RingCT for each transaction
+    let ScannableBlock { block, transactions, output_index_for_first_ringct_output } = block;
+    if block.transactions.len() != transactions.len() {
+      Err(ScanError::InvalidScannableBlock(
+        "scanning a ScannableBlock with more/less transactions than it should have",
+      ))?;
+    }
+    let Some(mut output_index_for_first_ringct_output) = output_index_for_first_ringct_output
+    else {
+      return Ok(Timelocked(vec![]));
+    };
+
     if block.header.hardfork_version > 16 {
-      Err(RpcError::InternalError(format!(
+      Err(ScanError::UnsupportedProtocol(block.header.hardfork_version))?;
-        "scanning a hardfork {} block, when we only support up to 16",
-        block.header.hardfork_version
-      )))?;
     }
 
     // We obtain all TXs in full
@@ -256,80 +277,17 @@ impl InternalScanner {
       block.miner_transaction.hash(),
       Transaction::<Pruned>::from(block.miner_transaction.clone()),
     )];
-    let txs = rpc.get_pruned_transactions(&block.transactions).await?;
+    for (hash, tx) in block.transactions.iter().zip(transactions) {
-    for (hash, tx) in block.transactions.iter().zip(txs) {
       txs_with_hashes.push((*hash, tx));
     }
 
-    /*
-      Requesting the output index for each output we sucessfully scan would cause a loss of privacy
-      We could instead request the output indexes for all outputs we scan, yet this would notably
-      increase the amount of RPC calls we make.
-
-      We solve this by requesting the output index for the first RingCT output in the block, which
-      should be within the miner transaction. Then, as we scan transactions, we update the output
-      index ourselves.
-
-      Please note we only will scan RingCT outputs so we only need to track the RingCT output
-      index. This decision was made due to spending CN outputs potentially having burdensome
-      requirements (the need to make a v1 TX due to insufficient decoys).
-
-      We bound ourselves to only scanning RingCT outputs by only scanning v2 transactions. This is
-      safe and correct since:
-
-      1) v1 transactions cannot create RingCT outputs.
-
-         https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
-           /src/cryptonote_basic/cryptonote_format_utils.cpp#L866-L869
-
-      2) v2 miner transactions implicitly create RingCT outputs.
-
-         https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
-           /src/blockchain_db/blockchain_db.cpp#L232-L241
-
-      3) v2 transactions must create RingCT outputs.
-
-         https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c45
-           /src/cryptonote_core/blockchain.cpp#L3055-L3065
-
-         That does bound on the hard fork version being >= 3, yet all v2 TXs have a hard fork
-         version > 3.
-
-         https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
-           /src/cryptonote_core/blockchain.cpp#L3417
-    */
-
-    // Get the starting index
-    let mut tx_start_index_on_blockchain = {
-      let mut tx_start_index_on_blockchain = None;
-      for (hash, tx) in &txs_with_hashes {
-        // If this isn't a RingCT output, or there are no outputs, move to the next TX
-        if (!matches!(tx, Transaction::V2 { .. })) || tx.prefix().outputs.is_empty() {
-          continue;
-        }
-
-        let index = *rpc.get_o_indexes(*hash).await?.first().ok_or_else(|| {
-          RpcError::InvalidNode(
-            "requested output indexes for a TX with outputs and got none".to_string(),
-          )
-        })?;
-        tx_start_index_on_blockchain = Some(index);
-        break;
-      }
-      let Some(tx_start_index_on_blockchain) = tx_start_index_on_blockchain else {
-        // Block had no RingCT outputs
-        return Ok(Timelocked(vec![]));
-      };
-      tx_start_index_on_blockchain
-    };
-
     let mut res = Timelocked(vec![]);
     for (hash, tx) in txs_with_hashes {
       // Push all outputs into our result
       {
         let mut this_txs_outputs = vec![];
         core::mem::swap(
-          &mut self.scan_transaction(tx_start_index_on_blockchain, hash, &tx)?.0,
+          &mut self.scan_transaction(output_index_for_first_ringct_output, hash, &tx)?.0,
           &mut this_txs_outputs,
         );
         res.0.extend(this_txs_outputs);
@@ -337,7 +295,7 @@ impl InternalScanner {
 
       // Update the RingCT starting index for the next TX
       if matches!(tx, Transaction::V2 { .. }) {
-        tx_start_index_on_blockchain += u64::try_from(tx.prefix().outputs.len()).unwrap()
+        output_index_for_first_ringct_output += u64::try_from(tx.prefix().outputs.len()).unwrap()
       }
     }
 
@@ -384,8 +342,8 @@ impl Scanner {
   }
 
   /// Scan a block.
-  pub async fn scan(&mut self, rpc: &impl Rpc, block: &Block) -> Result<Timelocked, RpcError> {
+  pub fn scan(&mut self, block: ScannableBlock) -> Result<Timelocked, ScanError> {
-    self.0.scan(rpc, block).await
+    self.0.scan(block)
   }
 }
 
@@ -413,7 +371,7 @@ impl GuaranteedScanner {
   }
 
   /// Scan a block.
-  pub async fn scan(&mut self, rpc: &impl Rpc, block: &Block) -> Result<Timelocked, RpcError> {
+  pub fn scan(&mut self, block: ScannableBlock) -> Result<Timelocked, ScanError> {
-    self.0.scan(rpc, block).await
+    self.0.scan(block)
   }
 }

networks/monero/wallet/tests/add_data.rs

@@ -1,8 +1,12 @@
 use monero_serai::transaction::Transaction;
+use monero_simple_request_rpc::SimpleRequestRpc;
 use monero_wallet::{rpc::Rpc, extra::MAX_ARBITRARY_DATA_SIZE, send::SendError};
 
 mod runner;
 
+#[allow(clippy::upper_case_acronyms)]
+type SRR = SimpleRequestRpc;
+
 test!(
   add_single_data_less_than_max,
   (
@@ -15,9 +19,8 @@ test!(
       builder.add_payment(addr, 5);
       (builder.build().unwrap(), (arbitrary_data,))
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, data: (Vec<u8>,)| async move {
+    |_rpc: SRR, block, tx: Transaction, mut scanner: Scanner, data: (Vec<u8>,)| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.arbitrary_data()[0], data.0);
@@ -42,9 +45,8 @@ test!(
       builder.add_payment(addr, 5);
       (builder.build().unwrap(), data)
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, data: Vec<Vec<u8>>| async move {
+    |_rpc: SRR, block, tx: Transaction, mut scanner: Scanner, data: Vec<Vec<u8>>| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.arbitrary_data(), data);
@@ -70,9 +72,8 @@ test!(
       builder.add_payment(addr, 5);
       (builder.build().unwrap(), data)
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, data: Vec<u8>| async move {
+    |_rpc: SRR, block, tx: Transaction, mut scanner: Scanner, data: Vec<u8>| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.arbitrary_data(), vec![data]);

networks/monero/wallet/tests/decoys.rs

@@ -16,9 +16,8 @@ test!(
       builder.add_payment(addr, 2000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 2000000000000);
       output
@@ -94,9 +93,8 @@ test!(
       builder.add_payment(addr, 2000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 2000000000000);
       output

networks/monero/wallet/tests/runner/mod.rs

@@ -105,7 +105,11 @@ pub async fn get_miner_tx_output(rpc: &SimpleRequestRpc, view: &ViewPair) -> Wal
   rpc.generate_blocks(&view.legacy_address(Network::Mainnet), 60).await.unwrap();
 
   let block = rpc.get_block_by_number(start).await.unwrap();
-  scanner.scan(rpc, &block).await.unwrap().ignore_additional_timelock().swap_remove(0)
+  scanner
+    .scan(rpc.get_scannable_block(block).await.unwrap())
+    .unwrap()
+    .ignore_additional_timelock()
+    .swap_remove(0)
 }
 
 /// Make sure the weight and fee match the expected calculation.
@@ -315,6 +319,7 @@ macro_rules! test {
             rpc.publish_transaction(&signed).await.unwrap();
             let block =
               mine_until_unlocked(&rpc, &random_address().2, signed.hash()).await;
+            let block = rpc.get_scannable_block(block).await.unwrap();
             let tx = rpc.get_transaction(signed.hash()).await.unwrap();
             check_weight_and_fee(&tx, fee_rate);
             let scanner = Scanner::new(view.clone());
@@ -336,6 +341,7 @@ macro_rules! test {
             rpc.publish_transaction(&signed).await.unwrap();
             let block =
               mine_until_unlocked(&rpc, &random_address().2, signed.hash()).await;
+            let block = rpc.get_scannable_block(block).await.unwrap();
             let tx = rpc.get_transaction(signed.hash()).await.unwrap();
             if stringify!($name) != "spend_one_input_to_two_outputs_no_change" {
               // Skip weight and fee check for the above test because when there is no change,

networks/monero/wallet/tests/scan.rs

@@ -1,8 +1,14 @@
-use monero_serai::transaction::Transaction;
+use monero_simple_request_rpc::SimpleRequestRpc;
-use monero_wallet::{rpc::Rpc, address::SubaddressIndex, extra::PaymentId, GuaranteedScanner};
+use monero_wallet::{
+  transaction::Transaction, rpc::Rpc, address::SubaddressIndex, extra::PaymentId, GuaranteedScanner,
+};
 
 mod runner;
 
+#[allow(clippy::upper_case_acronyms)]
+type SRR = SimpleRequestRpc;
+type Tx = Transaction;
+
 test!(
   scan_standard_address,
   (
@@ -12,8 +18,8 @@ test!(
       builder.add_payment(view.legacy_address(Network::Mainnet), 5);
       (builder.build().unwrap(), scanner)
     },
-    |rpc, block, tx: Transaction, _, mut state: Scanner| async move {
+    |_rpc: SRR, block, tx: Transaction, _, mut state: Scanner| async move {
-      let output = state.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
+      let output = state.scan(block).unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       let dummy_payment_id = PaymentId::Encrypted([0u8; 8]);
@@ -35,9 +41,8 @@ test!(
       builder.add_payment(view.subaddress(Network::Mainnet, subaddress), 5);
       (builder.build().unwrap(), (scanner, subaddress))
     },
-    |rpc, block, tx: Transaction, _, mut state: (Scanner, SubaddressIndex)| async move {
+    |_rpc: SRR, block, tx: Transaction, _, mut state: (Scanner, SubaddressIndex)| async move {
-      let output =
+      let output = state.0.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.subaddress(), Some(state.1));
@@ -58,9 +63,8 @@ test!(
       builder.add_payment(view.legacy_integrated_address(Network::Mainnet, payment_id), 5);
       (builder.build().unwrap(), (scanner, payment_id))
     },
-    |rpc, block, tx: Transaction, _, mut state: (Scanner, [u8; 8])| async move {
+    |_rpc: SRR, block, tx: Transaction, _, mut state: (Scanner, [u8; 8])| async move {
-      let output =
+      let output = state.0.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.payment_id(), Some(PaymentId::Encrypted(state.1)));
@@ -77,9 +81,8 @@ test!(
       builder.add_payment(view.address(Network::Mainnet, None, None), 5);
       (builder.build().unwrap(), scanner)
     },
-    |rpc, block, tx: Transaction, _, mut scanner: GuaranteedScanner| async move {
+    |_rpc: SRR, block, tx: Transaction, _, mut scanner: GuaranteedScanner| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.subaddress(), None);
@@ -100,9 +103,8 @@ test!(
       builder.add_payment(view.address(Network::Mainnet, Some(subaddress), None), 5);
       (builder.build().unwrap(), (scanner, subaddress))
     },
-    |rpc, block, tx: Transaction, _, mut state: (GuaranteedScanner, SubaddressIndex)| async move {
+    |_rpc: SRR, block, tx: Tx, _, mut state: (GuaranteedScanner, SubaddressIndex)| async move {
-      let output =
+      let output = state.0.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.subaddress(), Some(state.1));
@@ -122,9 +124,8 @@ test!(
       builder.add_payment(view.address(Network::Mainnet, None, Some(payment_id)), 5);
       (builder.build().unwrap(), (scanner, payment_id))
     },
-    |rpc, block, tx: Transaction, _, mut state: (GuaranteedScanner, [u8; 8])| async move {
+    |_rpc: SRR, block, tx: Transaction, _, mut state: (GuaranteedScanner, [u8; 8])| async move {
-      let output =
+      let output = state.0.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.payment_id(), Some(PaymentId::Encrypted(state.1)));
@@ -132,7 +133,6 @@ test!(
   ),
 );
 
-#[rustfmt::skip]
 test!(
   scan_guaranteed_integrated_subaddress,
   (
@@ -149,14 +149,8 @@ test!(
       builder.add_payment(view.address(Network::Mainnet, Some(subaddress), Some(payment_id)), 5);
       (builder.build().unwrap(), (scanner, payment_id, subaddress))
     },
-    |
+    |_rpc, block, tx: Tx, _, mut state: (GuaranteedScanner, [u8; 8], SubaddressIndex)| async move {
-      rpc,
+      let output = state.0.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-      block,
-      tx: Transaction,
-      _,
-      mut state: (GuaranteedScanner, [u8; 8], SubaddressIndex),
-    | async move {
-      let output = state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
       assert_eq!(output.payment_id(), Some(PaymentId::Encrypted(state.1)));

networks/monero/wallet/tests/send.rs

@@ -4,13 +4,21 @@ use rand_core::OsRng;
 
 use monero_simple_request_rpc::SimpleRequestRpc;
 use monero_wallet::{
-  ringct::RctType, transaction::Transaction, rpc::Rpc, address::SubaddressIndex, extra::Extra,
+  ringct::RctType,
+  transaction::Transaction,
+  rpc::{ScannableBlock, Rpc},
+  address::SubaddressIndex,
+  extra::Extra,
   WalletOutput, OutputWithDecoys,
 };
 
 mod runner;
 use runner::{SignableTransactionBuilder, ring_len};
 
+#[allow(clippy::upper_case_acronyms)]
+type SRR = SimpleRequestRpc;
+type SB = ScannableBlock;
+
 // Set up inputs, select decoys, then add them to the TX builder
 async fn add_inputs(
   rct_type: RctType,
@@ -40,9 +48,8 @@ test!(
       builder.add_payment(addr, 5);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 5);
     },
@@ -57,8 +64,8 @@ test!(
       builder.add_payment(addr, 2000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let mut outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let mut outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 2);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].transaction(), tx.hash());
@@ -74,9 +81,8 @@ test!(
       builder.add_payment(addr, 6);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 6);
     },
@@ -93,8 +99,8 @@ test!(
       builder.add_payment(addr, 1000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 1000000000000);
@@ -130,17 +136,15 @@ test!(
         .add_payment(sub_view.subaddress(Network::Mainnet, SubaddressIndex::new(0, 1).unwrap()), 1);
       (builder.build().unwrap(), (change_view, sub_view))
     },
-    |rpc, block, tx: Transaction, _, views: (ViewPair, ViewPair)| async move {
+    |_rpc: SRR, block: SB, tx: Transaction, _, views: (ViewPair, ViewPair)| async move {
       // Make sure the change can pick up its output
       let mut change_scanner = Scanner::new(views.0);
-      assert!(
+      assert!(change_scanner.scan(block.clone()).unwrap().not_additionally_locked().len() == 1);
-        change_scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().len() == 1
-      );
 
       // Make sure the subaddress can pick up its output
       let mut sub_scanner = Scanner::new(views.1);
       sub_scanner.register_subaddress(SubaddressIndex::new(0, 1).unwrap());
-      let sub_outputs = sub_scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let sub_outputs = sub_scanner.scan(block).unwrap().not_additionally_locked();
       assert!(sub_outputs.len() == 1);
       assert_eq!(sub_outputs[0].transaction(), tx.hash());
       assert_eq!(sub_outputs[0].commitment().amount, 1);
@@ -165,8 +169,8 @@ test!(
       builder.add_payment(addr, 2000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 2000000000000);
@@ -179,9 +183,8 @@ test!(
       builder.add_payment(addr, 2);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let output =
+      let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-        scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
       assert_eq!(output.transaction(), tx.hash());
       assert_eq!(output.commitment().amount, 2);
     },
@@ -195,8 +198,8 @@ test!(
       builder.add_payment(addr, 1000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 1000000000000);
@@ -212,8 +215,8 @@ test!(
       }
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let mut scanned_tx = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let mut scanned_tx = scanner.scan(block).unwrap().not_additionally_locked();
 
       let mut output_amounts = HashSet::new();
       for i in 0 .. 15 {
@@ -237,8 +240,8 @@ test!(
       builder.add_payment(addr, 1000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 1000000000000);
@@ -263,10 +266,14 @@ test!(
 
       (builder.build().unwrap(), (scanner, subaddresses))
     },
-    |rpc, block, tx: Transaction, _, mut state: (Scanner, Vec<SubaddressIndex>)| async move {
+    |_rpc: SimpleRequestRpc,
+     block,
+     tx: Transaction,
+     _,
+     mut state: (Scanner, Vec<SubaddressIndex>)| async move {
       use std::collections::HashMap;
 
-      let mut scanned_tx = state.0.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let mut scanned_tx = state.0.scan(block).unwrap().not_additionally_locked();
 
       let mut output_amounts_by_subaddress = HashMap::new();
       for i in 0 .. 15 {
@@ -294,8 +301,8 @@ test!(
       builder.add_payment(addr, 1000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 1000000000000);
@@ -320,8 +327,8 @@ test!(
 
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let mut outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let mut outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 2);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[1].transaction(), tx.hash());
@@ -345,8 +352,8 @@ test!(
       builder.add_payment(addr, 1000000000000);
       (builder.build().unwrap(), ())
     },
-    |rpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
+    |_rpc: SimpleRequestRpc, block, tx: Transaction, mut scanner: Scanner, ()| async move {
-      let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = scanner.scan(block).unwrap().not_additionally_locked();
       assert_eq!(outputs.len(), 1);
       assert_eq!(outputs[0].transaction(), tx.hash());
       assert_eq!(outputs[0].commitment().amount, 1000000000000);
@@ -381,11 +388,11 @@ test!(
       builder.add_payment(view.legacy_address(Network::Mainnet), 1);
       (builder.build().unwrap(), change_view)
     },
-    |rpc, block, _, _, change_view: ViewPair| async move {
+    |_rpc: SimpleRequestRpc, block, _, _, change_view: ViewPair| async move {
       // Make sure the change can pick up its output
       let mut change_scanner = Scanner::new(change_view);
       change_scanner.register_subaddress(SubaddressIndex::new(0, 1).unwrap());
-      let outputs = change_scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+      let outputs = change_scanner.scan(block).unwrap().not_additionally_locked();
       assert!(outputs.len() == 1);
       assert!(outputs[0].subaddress().unwrap().account() == 0);
       assert!(outputs[0].subaddress().unwrap().address() == 1);

networks/monero/wallet/tests/wallet2_compatibility.rs

@@ -106,6 +106,7 @@ async fn from_wallet_rpc_to_self(spec: AddressSpec) {
 
   // unlock it
   let block = runner::mine_until_unlocked(&daemon_rpc, &wallet_rpc_addr, tx_hash).await;
+  let block = daemon_rpc.get_scannable_block(block).await.unwrap();
 
   // Create the scanner
   let mut scanner = Scanner::new(view_pair);
@@ -114,8 +115,7 @@ async fn from_wallet_rpc_to_self(spec: AddressSpec) {
   }
 
   // Retrieve it and scan it
-  let output =
+  let output = scanner.scan(block).unwrap().not_additionally_locked().swap_remove(0);
-    scanner.scan(&daemon_rpc, &block).await.unwrap().not_additionally_locked().swap_remove(0);
   assert_eq!(output.transaction(), tx_hash);
 
   runner::check_weight_and_fee(&daemon_rpc.get_transaction(tx_hash).await.unwrap(), fee_rate);

processor/src/networks/monero.rs

@@ -520,7 +520,13 @@ impl Network for Monero {
 
   async fn get_outputs(&self, block: &Block, key: EdwardsPoint) -> Vec<Output> {
     let outputs = loop {
-      match Self::scanner(key).scan(&self.rpc, block).await {
+      match self
+        .rpc
+        .get_scannable_block(block.clone())
+        .await
+        .map_err(|e| format!("{e:?}"))
+        .and_then(|block| Self::scanner(key).scan(block).map_err(|e| format!("{e:?}")))
+      {
         Ok(outputs) => break outputs,
         Err(e) => {
           log::error!("couldn't scan block {}: {e:?}", hex::encode(block.id()));
@@ -738,8 +744,10 @@ impl Network for Monero {
     }
 
     let new_block = self.rpc.get_block_by_number(new_block).await.unwrap();
-    let mut outputs =
+    let mut outputs = Self::test_scanner()
-      Self::test_scanner().scan(&self.rpc, &new_block).await.unwrap().ignore_additional_timelock();
+      .scan(self.rpc.get_scannable_block(new_block.clone()).await.unwrap())
+      .unwrap()
+      .ignore_additional_timelock();
     let output = outputs.swap_remove(0);
 
     let amount = output.commitment().amount;

tests/full-stack/src/tests/mint_and_burn.rs

@@ -357,8 +357,7 @@ async fn mint_and_burn_test() {
       let view_pair = ViewPair::new(ED25519_BASEPOINT_POINT, Zeroizing::new(Scalar::ONE)).unwrap();
       let mut scanner = Scanner::new(view_pair.clone());
       let output = scanner
-        .scan(&rpc, &rpc.get_block_by_number(1).await.unwrap())
+        .scan(rpc.get_scannable_block_by_number(1).await.unwrap())
-        .await
         .unwrap()
         .additional_timelock_satisfied_by(rpc.get_height().await.unwrap(), 0)
         .swap_remove(0);
@@ -587,7 +586,10 @@ async fn mint_and_burn_test() {
       while i < (5 * 6) {
         if let Ok(block) = rpc.get_block_by_number(start_monero_block).await {
           start_monero_block += 1;
-          let outputs = scanner.scan(&rpc, &block).await.unwrap().not_additionally_locked();
+          let outputs = scanner
+            .scan(rpc.get_scannable_block(block.clone()).await.unwrap())
+            .unwrap()
+            .not_additionally_locked();
           if !outputs.is_empty() {
             assert_eq!(outputs.len(), 1);
 

tests/processor/src/networks.rs

@@ -429,8 +429,7 @@ impl Wallet {
             block.transactions.contains(&last_tx.1)
           {
             outputs = Scanner::new(view_pair.clone())
-              .scan(&rpc, &block)
+              .scan(rpc.get_scannable_block(block).await.unwrap())
-              .await
               .unwrap()
               .ignore_additional_timelock();
           }