Mst efficiency improvement (summa-dev#188)

* feat: tree building rules

* feat: add `get_middle_node_hash_preimage` and `get_middle_node_hash_preimage` methods

* feat: update `generate_proof`

* fix: `generate_proof`

* fix: modify middle nodes hashing logic in circuit

* feat: update `MerkleProof`

* feat: add further constraint on `MstInclusionCircuit`

* feat: rm `test_balance_not_in_range`

* refactor: update `MerkleProof`

* chore: fix `backend`

* test: fix `backend`

* fix: testing

* fix: modify `MstInclusionCircuit` struct

* Revert "fix: modify `MstInclusionCircuit` struct"

This reverts commit e3ba8e6.

* chore: update `benches`

* fix: move poseidon hasher APIs to `Node`

* chore: add guide on `MerkleProof `

* chore: update `where` clause in backend

* chore: update comments

* chore: move `generate_leaf_hash` outside of `zk_prover`

* chore: add `ethers` legacy feature

* chore: update verifier contract

* fix: removed minting erc20 on the backend test

* chore: rm unused imports

* feat: remove `Node::leaf()`

* feat: rm `Node::middle()`

* Revert "feat: remove `Node::leaf()`"

This reverts commit ae539a2.

* chore: DRY code

---------

Co-authored-by: sifnoc <[email protected]>

backend/Cargo.toml

@@ -13,12 +13,13 @@ futures = "0.3.28"
 num-bigint = "0.4.3"
 serde = { version = "1.0.166", features = ["derive"] }
 snark-verifier-sdk = { git = "https://github.com/privacy-scaling-explorations/snark-verifier", version = "0.1.1" }
-ethers = { version = "2.0.7", default-features = false, features = ["ethers-solc","legacy"] }
+ethers = { version = "2.0.7", default-features = false, features = ["ethers-solc", "legacy"] }
 reqwest = { version = "0.11", features = ["json"] }
 serde_json = "1.0.64"
 tokio = { version = "1.7.1", features = ["full"] }
 base64 = "0.13"
 bincode = "1.3.3"
+num-traits = "0.2.14"
 
 [build-dependencies]
 ethers = { version = "2.0.7", default-features = false, features = ["ethers-solc", "legacy"] }

backend/README.md

@@ -62,7 +62,7 @@ We have provided a bash script to automate the process of updating the verifier
 Ensure you have the necessary permissions to execute the script.
 
 ```
-backend $ chmod +x scripts/update_verifier_contract.sh
+backend $ scripts/update_verifier_contract.sh
 ```
 
 ## Summa solvency flow example

backend/examples/summa_solvency_flow.rs

@@ -7,12 +7,13 @@ use serde_json::{from_reader, to_string_pretty};
 use summa_backend::{
     apis::{
         address_ownership::AddressOwnership,
+        leaf_hash_from_inputs,
         round::{MstInclusionProof, Round},
     },
     contracts::signer::{AddressInput, SummaSigner},
     tests::initialize_test_env,
 };
-use summa_solvency::merkle_sum_tree::{utils::generate_leaf_hash, MerkleSumTree};
+use summa_solvency::merkle_sum_tree::MerkleSumTree;
 
 const N_ASSETS: usize = 2;
 const USER_INDEX: usize = 0;
@@ -103,12 +104,12 @@ async fn main() -> Result<(), Box<dyn Error>> {
     // It's assumed that both `user_name` and `balances` are provided by the CEX.
     // The `balances` represent the user's balances on the CEX at `snapshot_time`.
     let user_name = "dxGaEAii".to_string();
-    let balances = vec![11888, 41163];
+    let balances = vec!["11888".to_string(), "41163".to_string()];
 
     let leaf_hash = public_inputs[0];
     assert_eq!(
         leaf_hash,
-        generate_leaf_hash::<N_ASSETS>(user_name.clone(), balances.clone())
+        leaf_hash_from_inputs::<N_ASSETS>(user_name.clone(), balances.clone())
     );
 
     // Get `mst_root` from contract. the `mst_root` is disptached by CEX with specific time `snapshot_time`.

backend/scripts/update_verifier_contract.sh

@@ -6,8 +6,13 @@ echo "1. Building verifier contracts"
 cd ../zk_prover
 cargo run --release --example gen_inclusion_verifier
 
+# Generate Commitment for Merkle Sum Tree
+echo "2. Generate Commitment for Merkle Sum Tree"
+cd ../zk_prover
+cargo run --release --example gen_commitment
+
 # Deploy contracts to local environment
-echo "2. Deploying contracts to local environment"
+echo "3. Deploying contracts to local environment"
 cd ../contracts
 npm install
 npx hardhat node &
@@ -16,7 +21,7 @@ sleep 5
 npx hardhat run scripts/deploy.ts --network localhost
 
 # Generate interface files for Backend
-echo "3. Generating interface files for Backend"
+echo "4. Generating interface files for Backend"
 cd ../backend
 cargo build
 

backend/src/apis/mod.rs

@@ -1,3 +1,25 @@
 pub mod address_ownership;
 pub mod csv_parser;
 pub mod round;
+
+use ethers::types::U256;
+use num_bigint::BigUint;
+use num_traits::Num;
+use summa_solvency::merkle_sum_tree::Entry;
+
+pub fn leaf_hash_from_inputs<const N_ASSETS: usize>(username: String, balances: Vec<String>) -> U256
+where
+    [usize; N_ASSETS + 1]: Sized,
+{
+    // Convert balances to BigUint
+    let balances: Vec<BigUint> = balances
+        .iter()
+        .map(|balance| BigUint::from_str_radix(balance, 10).unwrap())
+        .collect();
+
+    let entry: Entry<N_ASSETS> = Entry::new(username, balances.try_into().unwrap()).unwrap();
+
+    // Convert Fp to U256
+    let hash_str = format!("{:?}", entry.compute_leaf().hash);
+    U256::from_str_radix(&hash_str, 16).unwrap()
+}

backend/src/apis/round.rs

@@ -53,14 +53,17 @@ impl<const LEVELS: usize, const N_ASSETS: usize, const N_BYTES: usize>
     Round<'_, LEVELS, N_ASSETS, N_BYTES>
 where
     [usize; N_ASSETS + 1]: Sized,
-    [usize; 2 * (1 + N_ASSETS)]: Sized,
+    [usize; N_ASSETS + 2]: Sized,
 {
     pub fn new<'a>(
         signer: &'a SummaSigner,
         mst: Box<dyn Tree<N_ASSETS, N_BYTES>>,
         params_path: &str,
         timestamp: u64,
-    ) -> Result<Round<'a, LEVELS, N_ASSETS, N_BYTES>, Box<dyn Error>> {
+    ) -> Result<Round<'a, LEVELS, N_ASSETS, N_BYTES>, Box<dyn Error>>
+    where
+        [(); N_ASSETS + 2]: Sized,
+    {
         Ok(Round {
             timestamp,
             snapshot: Snapshot::<LEVELS, N_ASSETS, N_BYTES>::new(mst, params_path).unwrap(),
@@ -109,7 +112,10 @@ where
     pub fn get_proof_of_inclusion(
         &self,
         user_index: usize,
-    ) -> Result<MstInclusionProof, &'static str> {
+    ) -> Result<MstInclusionProof, &'static str>
+    where
+        [(); N_ASSETS + 2]: Sized,
+    {
         Ok(self
             .snapshot
             .generate_proof_of_inclusion(user_index)
@@ -121,7 +127,7 @@ impl<const LEVELS: usize, const N_ASSETS: usize, const N_BYTES: usize>
     Snapshot<LEVELS, N_ASSETS, N_BYTES>
 where
     [usize; N_ASSETS + 1]: Sized,
-    [usize; 2 * (1 + N_ASSETS)]: Sized,
+    [usize; N_ASSETS + 2]: Sized,
 {
     pub fn new(
         mst: Box<dyn Tree<N_ASSETS, N_BYTES>>,
@@ -146,11 +152,12 @@ where
     pub fn generate_proof_of_inclusion(
         &self,
         user_index: usize,
-    ) -> Result<MstInclusionProof, &'static str> {
+    ) -> Result<MstInclusionProof, &'static str>
+    where
+        [(); N_ASSETS + 2]: Sized,
+    {
         let merkle_proof = self.mst.generate_proof(user_index).unwrap();
-        let user_entry = self.mst.get_entry(user_index).clone();
-        let circuit =
-            MstInclusionCircuit::<LEVELS, N_ASSETS, N_BYTES>::init(merkle_proof, user_entry);
+        let circuit = MstInclusionCircuit::<LEVELS, N_ASSETS, N_BYTES>::init(merkle_proof);
 
         // Currently, default manner of generating a inclusion proof for solidity-verifier.
         let calldata = gen_proof_solidity_calldata(

backend/src/contracts/deployments.json

@@ -1 +1 @@
-{"31337":{"address":"0xcf7ed3acca5a467e9e704c703e8d87f634fb0fc9"}}
+{"31337":{"address":"0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512"}}