chore: move generate_leaf_hash outside of zk_prover

backend/Cargo.toml

@@ -19,6 +19,7 @@ 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"] }

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;
@@ -111,12 +112,12 @@ 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/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()
+}

zk_prover/src/merkle_sum_tree/utils/mod.rs

@@ -1,9 +1,7 @@
 mod build_tree;
 mod csv_parser;
-mod generate_leaf_hash;
 mod operation_helpers;
 
 pub use build_tree::{build_leaves_from_entries, build_merkle_tree_from_leaves};
 pub use csv_parser::parse_csv_to_entries;
-pub use generate_leaf_hash::generate_leaf_hash;
 pub use operation_helpers::*;