feat(core): adds a get proof endpoint in zks namespace (#455)

## What ❔

This PR adds a new JSON-RPC endpoint `zks_getProof` that allows users to
request proofs
of data in the tree that can later be verified against storarage roots
at a given point
in batch history.

---------

Co-authored-by: Roman Brodetski <[email protected]>

core/lib/config/src/configs/api.rs

@@ -87,6 +87,8 @@ pub struct Web3JsonRpcConfig {
     /// The value is per active connection.
     /// Note: For HTTP, rate limiting is expected to be configured on the infra level.
     pub websocket_requests_per_minute_limit: Option<u32>,
+    /// Tree API url, currently used to proxy `getProof` calls to the tree
+    pub tree_api_url: Option<String>,
 }
 
 impl Web3JsonRpcConfig {
@@ -123,6 +125,7 @@ impl Web3JsonRpcConfig {
             max_batch_request_size: Default::default(),
             max_response_body_size_mb: Default::default(),
             websocket_requests_per_minute_limit: Default::default(),
+            tree_api_url: None,
         }
     }
 
@@ -205,6 +208,10 @@ impl Web3JsonRpcConfig {
         // The default limit is chosen to be reasonably permissive.
         self.websocket_requests_per_minute_limit.unwrap_or(6000)
     }
+
+    pub fn tree_api_url(&self) -> Option<String> {
+        self.tree_api_url.clone()
+    }
 }
 
 #[derive(Debug, Deserialize, Clone, PartialEq)]

core/lib/env_config/src/api.rs

@@ -87,6 +87,7 @@ mod tests {
                 max_batch_request_size: Some(200),
                 max_response_body_size_mb: Some(10),
                 websocket_requests_per_minute_limit: Some(10),
+                tree_api_url: None,
             },
             contract_verification: ContractVerificationApiConfig {
                 port: 3070,

core/lib/types/src/api/mod.rs

@@ -684,3 +684,19 @@ pub struct L1BatchDetails {
     #[serde(flatten)]
     pub base: BlockDetailsBase,
 }
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct StorageProof {
+    pub key: H256,
+    pub proof: Vec<H256>,
+    pub value: H256,
+    pub index: u64,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Proof {
+    pub address: Address,
+    pub storage_proof: Vec<StorageProof>,
+}

core/lib/web3_decl/src/error.rs

@@ -37,4 +37,6 @@ pub enum Web3Error {
     InvalidFilterBlockHash,
     #[error("Query returned more than {0} results. Try smaller range of blocks")]
     TooManyLogs(usize),
+    #[error("Tree API is not available")]
+    TreeApiUnavailable,
 }

core/lib/zksync_core/src/api_server/tree/mod.rs

@@ -119,14 +119,13 @@ impl TreeApiClient for AsyncTreeReader {
 
 /// [`TreeApiClient`] implementation requesting data from a Merkle tree API server.
 #[derive(Debug, Clone)]
-pub(crate) struct TreeApiHttpClient {
+pub struct TreeApiHttpClient {
     inner: reqwest::Client,
     info_url: String,
     proofs_url: String,
 }
 
 impl TreeApiHttpClient {
-    #[cfg(test)] // temporary measure until `TreeApiClient` is required by other components
     pub fn new(url_base: &str) -> Self {
         Self {
             inner: reqwest::Client::new(),

core/lib/zksync_core/src/api_server/web3/backend_jsonrpc/error.rs

@@ -22,6 +22,7 @@ pub fn into_jsrpc_error(err: Web3Error) -> Error {
             Web3Error::SubmitTransactionError(_, _) | Web3Error::SerializationError(_) => 3.into(),
             Web3Error::PubSubTimeout => 4.into(),
             Web3Error::RequestTimeout => 5.into(),
+            Web3Error::TreeApiUnavailable => 6.into(),
         },
         message: match err {
             Web3Error::SubmitTransactionError(_, _) => err.to_string(),

core/lib/zksync_core/src/api_server/web3/backend_jsonrpc/namespaces/zks.rs

@@ -9,7 +9,7 @@ use jsonrpc_derive::rpc;
 // Workspace uses
 use zksync_types::{
     api::{
-        BlockDetails, BridgeAddresses, L1BatchDetails, L2ToL1LogProof, ProtocolVersion,
+        BlockDetails, BridgeAddresses, L1BatchDetails, L2ToL1LogProof, Proof, ProtocolVersion,
         TransactionDetails,
     },
     fee::Fee,
@@ -111,6 +111,14 @@ pub trait ZksNamespaceT {
 
     #[rpc(name = "zks_getLogsWithVirtualBlocks")]
     fn get_logs_with_virtual_blocks(&self, filter: Filter) -> BoxFuture<Result<Vec<Log>>>;
+
+    #[rpc(name = "zks_getProof")]
+    fn get_proof(
+        &self,
+        address: Address,
+        keys: Vec<H256>,
+        l1_batch_number: L1BatchNumber,
+    ) -> BoxFuture<Result<Proof>>;
 }
 
 impl<G: L1GasPriceProvider + Send + Sync + 'static> ZksNamespaceT for ZksNamespace<G> {
@@ -308,4 +316,19 @@ impl<G: L1GasPriceProvider + Send + Sync + 'static> ZksNamespaceT for ZksNamespa
                 .map_err(into_jsrpc_error)
         })
     }
+
+    fn get_proof(
+        &self,
+        address: Address,
+        keys: Vec<H256>,
+        l1_batch_number: L1BatchNumber,
+    ) -> BoxFuture<Result<Proof>> {
+        let self_ = self.clone();
+        Box::pin(async move {
+            self_
+                .get_proofs_impl(address, keys.clone(), l1_batch_number)
+                .await
+                .map_err(into_jsrpc_error)
+        })
+    }
 }

core/lib/zksync_core/src/api_server/web3/backend_jsonrpsee/mod.rs

@@ -29,6 +29,7 @@ pub fn into_jsrpc_error(err: Web3Error) -> ErrorObjectOwned {
             Web3Error::SubmitTransactionError(_, _) | Web3Error::SerializationError(_) => 3,
             Web3Error::PubSubTimeout => 4,
             Web3Error::RequestTimeout => 5,
+            Web3Error::TreeApiUnavailable => 6,
         },
         match err {
             Web3Error::SubmitTransactionError(ref message, _) => message.clone(),

core/lib/zksync_core/src/api_server/web3/mod.rs

@@ -27,7 +27,7 @@ use zksync_web3_decl::{
 
 use crate::{
     api_server::{
-        execution_sandbox::VmConcurrencyBarrier, tx_sender::TxSender,
+        execution_sandbox::VmConcurrencyBarrier, tree::TreeApiHttpClient, tx_sender::TxSender,
         web3::backend_jsonrpc::batch_limiter_middleware::RateLimitMetadata,
     },
     l1_gas_price::L1GasPriceProvider,
@@ -136,6 +136,7 @@ pub struct ApiBuilder<G> {
     polling_interval: Option<Duration>,
     namespaces: Option<Vec<Namespace>>,
     logs_translator_enabled: bool,
+    tree_api_url: Option<String>,
 }
 
 impl<G> ApiBuilder<G> {
@@ -159,6 +160,7 @@ impl<G> ApiBuilder<G> {
             namespaces: None,
             config,
             logs_translator_enabled: false,
+            tree_api_url: None,
         }
     }
 
@@ -255,6 +257,11 @@ impl<G> ApiBuilder<G> {
         self.logs_translator_enabled = true;
         self
     }
+
+    pub fn with_tree_api(mut self, tree_api_url: Option<String>) -> Self {
+        self.tree_api_url = tree_api_url;
+        self
+    }
 }
 
 impl<G: 'static + Send + Sync + L1GasPriceProvider> ApiBuilder<G> {
@@ -280,6 +287,9 @@ impl<G: 'static + Send + Sync + L1GasPriceProvider> ApiBuilder<G> {
             api_config: self.config,
             last_sealed_miniblock,
             logs_translator_enabled: self.logs_translator_enabled,
+            tree_api: self
+                .tree_api_url
+                .map(|url| TreeApiHttpClient::new(url.as_str())),
         }
     }
 

core/lib/zksync_core/src/api_server/web3/namespaces/zks.rs

@@ -6,26 +6,28 @@ use zksync_dal::StorageProcessor;
 use zksync_mini_merkle_tree::MiniMerkleTree;
 use zksync_types::{
     api::{
-        BlockDetails, BridgeAddresses, GetLogsFilter, L1BatchDetails, L2ToL1LogProof,
-        ProtocolVersion, TransactionDetails,
+        BlockDetails, BridgeAddresses, GetLogsFilter, L1BatchDetails, L2ToL1LogProof, Proof,
+        ProtocolVersion, StorageProof, TransactionDetails,
     },
     fee::Fee,
     l1::L1Tx,
     l2::L2Tx,
     l2_to_l1_log::L2ToL1Log,
     tokens::ETHEREUM_ADDRESS,
     transaction_request::CallRequest,
-    L1BatchNumber, MiniblockNumber, Transaction, L1_MESSENGER_ADDRESS, L2_ETH_TOKEN_ADDRESS,
-    MAX_GAS_PER_PUBDATA_BYTE, REQUIRED_L1_TO_L2_GAS_PER_PUBDATA_BYTE, U256, U64,
+    AccountTreeId, L1BatchNumber, MiniblockNumber, StorageKey, Transaction, L1_MESSENGER_ADDRESS,
+    L2_ETH_TOKEN_ADDRESS, MAX_GAS_PER_PUBDATA_BYTE, REQUIRED_L1_TO_L2_GAS_PER_PUBDATA_BYTE, U256,
+    U64,
 };
 use zksync_utils::{address_to_h256, ratio_to_big_decimal_normalized};
 use zksync_web3_decl::{
     error::Web3Error,
     types::{Address, Filter, Log, Token, H256},
 };
 
-use crate::api_server::web3::{
-    backend_jsonrpc::error::internal_error, metrics::API_METRICS, RpcState,
+use crate::api_server::{
+    tree::TreeApiClient,
+    web3::{backend_jsonrpc::error::internal_error, metrics::API_METRICS, RpcState},
 };
 use crate::l1_gas_price::L1GasPriceProvider;
 
@@ -620,4 +622,42 @@ impl<G: L1GasPriceProvider> ZksNamespace<G> {
     ) -> Result<Vec<Log>, Web3Error> {
         self.state.translate_get_logs(filter).await
     }
+
+    #[tracing::instrument(skip_all)]
+    pub async fn get_proofs_impl(
+        &self,
+        address: Address,
+        keys: Vec<H256>,
+        l1_batch_number: L1BatchNumber,
+    ) -> Result<Proof, Web3Error> {
+        const METHOD_NAME: &str = "get_proofs";
+
+        let hashed_keys = keys
+            .iter()
+            .map(|key| StorageKey::new(AccountTreeId::new(address), *key).hashed_key_u256())
+            .collect();
+
+        let storage_proof = self
+            .state
+            .tree_api
+            .as_ref()
+            .ok_or(Web3Error::TreeApiUnavailable)?
+            .get_proofs(l1_batch_number, hashed_keys)
+            .await
+            .map_err(|err| internal_error(METHOD_NAME, err))?
+            .into_iter()
+            .zip(keys)
+            .map(|(proof, key)| StorageProof {
+                key,
+                proof: proof.merkle_path,
+                value: proof.value,
+                index: proof.index,
+            })
+            .collect();
+
+        Ok(Proof {
+            address,
+            storage_proof,
+        })
+    }
 }

core/lib/zksync_core/src/api_server/web3/state.rs

@@ -31,6 +31,7 @@ use super::metrics::API_METRICS;
 use crate::{
     api_server::{
         execution_sandbox::BlockArgs,
+        tree::TreeApiHttpClient,
         tx_sender::TxSender,
         web3::{
             backend_jsonrpc::error::internal_error, namespaces::eth::EVENT_TOPIC_NUMBER_LIMIT,
@@ -167,6 +168,7 @@ impl SealedMiniblockNumber {
 pub struct RpcState<E> {
     pub installed_filters: Arc<RwLock<Filters>>,
     pub connection_pool: ConnectionPool,
+    pub tree_api: Option<TreeApiHttpClient>,
     pub tx_sender: TxSender<E>,
     pub sync_state: Option<SyncState>,
     pub(super) api_config: InternalApiConfig,
@@ -185,6 +187,7 @@ impl<E> Clone for RpcState<E> {
             installed_filters: self.installed_filters.clone(),
             connection_pool: self.connection_pool.clone(),
             tx_sender: self.tx_sender.clone(),
+            tree_api: self.tree_api.clone(),
             sync_state: self.sync_state.clone(),
             api_config: self.api_config.clone(),
             last_sealed_miniblock: self.last_sealed_miniblock.clone(),

core/lib/zksync_core/src/lib.rs

@@ -1364,6 +1364,7 @@ async fn run_ws_api<G: L1GasPriceProvider + Send + Sync + 'static>(
             )
             .with_polling_interval(api_config.web3_json_rpc.pubsub_interval())
             .with_threads(api_config.web3_json_rpc.ws_server_threads())
+            .with_tree_api(api_config.web3_json_rpc.tree_api_url())
             .with_tx_sender(tx_sender, vm_barrier)
             .enable_api_namespaces(Namespace::NON_DEBUG.to_vec());