feat(trie): proof blinded providers (#13085)

crates/trie/sparse/src/blinded.rs

@@ -55,3 +55,11 @@ impl BlindedProvider for DefaultBlindedProvider {
         Ok(None)
     }
 }
+
+/// Right pad the path with 0s and return as [`B256`].
+#[inline]
+pub fn pad_path_to_key(path: &Nibbles) -> B256 {
+    let mut padded = path.pack();
+    padded.resize(32, 0);
+    B256::from_slice(&padded)
+}

crates/trie/sparse/src/errors.rs

@@ -55,4 +55,7 @@ pub enum SparseTrieError {
     /// RLP error.
     #[error(transparent)]
     Rlp(#[from] alloy_rlp::Error),
+    /// Other.
+    #[error(transparent)]
+    Other(#[from] Box<dyn std::error::Error>),
 }

crates/trie/trie/Cargo.toml

@@ -17,6 +17,7 @@ reth-execution-errors.workspace = true
 reth-primitives.workspace = true
 reth-stages-types.workspace = true
 reth-storage-errors.workspace = true
+reth-trie-sparse.workspace = true
 reth-trie-common.workspace = true
 
 revm.workspace = true

crates/trie/trie/src/proof/blinded.rs

@@ -0,0 +1,116 @@
+use super::{Proof, StorageProof};
+use crate::{hashed_cursor::HashedCursorFactory, trie_cursor::TrieCursorFactory};
+use alloy_primitives::{
+    map::{HashMap, HashSet},
+    Bytes, B256,
+};
+use reth_trie_common::{prefix_set::TriePrefixSetsMut, Nibbles};
+use reth_trie_sparse::{
+    blinded::{pad_path_to_key, BlindedProvider, BlindedProviderFactory},
+    SparseTrieError,
+};
+use std::sync::Arc;
+
+/// Factory for instantiating providers capable of retrieving blinded trie nodes via proofs.
+#[derive(Debug)]
+pub struct ProofBlindedProviderFactory<T, H> {
+    /// The cursor factory for traversing trie nodes.
+    trie_cursor_factory: T,
+    /// The factory for hashed cursors.
+    hashed_cursor_factory: H,
+    /// A set of prefix sets that have changes.
+    prefix_sets: Arc<TriePrefixSetsMut>,
+}
+
+impl<T, H> BlindedProviderFactory for ProofBlindedProviderFactory<T, H>
+where
+    T: TrieCursorFactory + Clone,
+    H: HashedCursorFactory + Clone,
+{
+    type AccountNodeProvider = ProofBlindedAccountProvider<T, H>;
+    type StorageNodeProvider = ProofBlindedStorageProvider<T, H>;
+
+    fn account_node_provider(&self) -> Self::AccountNodeProvider {
+        ProofBlindedAccountProvider {
+            trie_cursor_factory: self.trie_cursor_factory.clone(),
+            hashed_cursor_factory: self.hashed_cursor_factory.clone(),
+            prefix_sets: self.prefix_sets.clone(),
+        }
+    }
+
+    fn storage_node_provider(&self, account: B256) -> Self::StorageNodeProvider {
+        ProofBlindedStorageProvider {
+            trie_cursor_factory: self.trie_cursor_factory.clone(),
+            hashed_cursor_factory: self.hashed_cursor_factory.clone(),
+            prefix_sets: self.prefix_sets.clone(),
+            account,
+        }
+    }
+}
+
+/// Blinded provider for retrieving account trie nodes by path.
+#[derive(Debug)]
+pub struct ProofBlindedAccountProvider<T, H> {
+    /// The cursor factory for traversing trie nodes.
+    trie_cursor_factory: T,
+    /// The factory for hashed cursors.
+    hashed_cursor_factory: H,
+    /// A set of prefix sets that have changes.
+    prefix_sets: Arc<TriePrefixSetsMut>,
+}
+
+impl<T, H> BlindedProvider for ProofBlindedAccountProvider<T, H>
+where
+    T: TrieCursorFactory + Clone,
+    H: HashedCursorFactory + Clone,
+{
+    type Error = SparseTrieError;
+
+    fn blinded_node(&mut self, path: Nibbles) -> Result<Option<Bytes>, Self::Error> {
+        let targets = HashMap::from_iter([(pad_path_to_key(&path), HashSet::default())]);
+        let proof =
+            Proof::new(self.trie_cursor_factory.clone(), self.hashed_cursor_factory.clone())
+                .with_prefix_sets_mut(self.prefix_sets.as_ref().clone())
+                .multiproof(targets)
+                .map_err(|error| SparseTrieError::Other(Box::new(error)))?;
+
+        Ok(proof.account_subtree.into_inner().remove(&path))
+    }
+}
+
+/// Blinded provider for retrieving storage trie nodes by path.
+#[derive(Debug)]
+pub struct ProofBlindedStorageProvider<T, H> {
+    /// The cursor factory for traversing trie nodes.
+    trie_cursor_factory: T,
+    /// The factory for hashed cursors.
+    hashed_cursor_factory: H,
+    /// A set of prefix sets that have changes.
+    prefix_sets: Arc<TriePrefixSetsMut>,
+    /// Target account.
+    account: B256,
+}
+
+impl<T, H> BlindedProvider for ProofBlindedStorageProvider<T, H>
+where
+    T: TrieCursorFactory + Clone,
+    H: HashedCursorFactory + Clone,
+{
+    type Error = SparseTrieError;
+
+    fn blinded_node(&mut self, path: Nibbles) -> Result<Option<Bytes>, Self::Error> {
+        let targets = HashSet::from_iter([pad_path_to_key(&path)]);
+        let storage_prefix_set =
+            self.prefix_sets.storage_prefix_sets.get(&self.account).cloned().unwrap_or_default();
+        let proof = StorageProof::new_hashed(
+            self.trie_cursor_factory.clone(),
+            self.hashed_cursor_factory.clone(),
+            self.account,
+        )
+        .with_prefix_set_mut(storage_prefix_set)
+        .storage_multiproof(targets)
+        .map_err(|error| SparseTrieError::Other(Box::new(error)))?;
+
+        Ok(proof.subtree.into_inner().remove(&path))
+    }
+}

crates/trie/trie/src/proof.rs → crates/trie/trie/src/proof/mod.rs

@@ -17,6 +17,9 @@ use reth_trie_common::{
     proof::ProofRetainer, AccountProof, MultiProof, StorageMultiProof, TrieAccount,
 };
 
+mod blinded;
+pub use blinded::*;
+
 /// A struct for generating merkle proofs.
 ///
 /// Proof generator adds the target address and slots to the prefix set, enables the proof retainer