From 4537bc61fc42f8322132a335668b0701a8920b01 Mon Sep 17 00:00:00 2001
From: Rostyslav Tyshko <tyshko.rostyslav@gmail.com>
Date: Mon, 2 Dec 2024 01:19:10 +0100
Subject: [PATCH] add generate_commitments and generate_nullifiers to se module

---
 node_core/src/executions/se.rs | 69 ++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 node_core/src/executions/se.rs

diff --git a/node_core/src/executions/se.rs b/node_core/src/executions/se.rs
new file mode 100644
index 0000000..17c0d5b
--- /dev/null
+++ b/node_core/src/executions/se.rs
@@ -0,0 +1,69 @@
+use k256::Scalar;
+use secp256k1_zkp::{compute_adaptive_blinding_factor, verify_commitments_sum_to_equal, CommitmentSecrets, Generator, PedersenCommitment, Tag, Tweak, SECP256K1};
+use rand::thread_rng;
+use sha2::{Digest, Sha256};
+use serde::{Serialize, Deserialize};
+use storage::{commitment::Commitment, commitments_sparse_merkle_tree::CommitmentsSparseMerkleTree, nullifier::UTXONullifier, nullifier_sparse_merkle_tree::NullifierSparseMerkleTree};
+use utxo::{
+    utxo_core::{UTXOPayload, UTXO},
+    utxo_tree::UTXOSparseMerkleTree,
+};
+use monotree::hasher::Blake3;
+use monotree::{Hasher, Monotree, Proof};
+use bincode;
+
+fn commitment_secrets_random(value: u64) -> CommitmentSecrets {
+    CommitmentSecrets {
+        value,
+        value_blinding_factor: Tweak::new(&mut thread_rng()),
+        generator_blinding_factor: Tweak::new(&mut thread_rng()),
+    }
+}
+
+pub fn tag_random() -> Tag {
+    use rand::thread_rng;
+    use rand::RngCore;
+
+    let mut bytes = [0u8; 32];
+    thread_rng().fill_bytes(&mut bytes);
+
+    Tag::from(bytes)
+}
+
+pub fn commit(comm: &CommitmentSecrets, tag: Tag) -> PedersenCommitment {
+    let generator = Generator::new_blinded(SECP256K1, tag, comm.generator_blinding_factor);
+
+    PedersenCommitment::new(SECP256K1, comm.value, comm.value_blinding_factor, generator)
+}
+
+// Hash function placeholder (replace with your cryptographic library's hash).
+fn hash(input: &[u8]) -> Vec<u8> {
+    Sha256::digest(input).to_vec()
+}
+
+// Generate nullifiers
+
+// takes the pedersen_commitment and nsk then 
+// returns a list of nullifiers, where the nullifier = hash(pedersen_commitment || nsk) where the hash function will be determined 
+
+pub fn generate_nullifiers(pedersen_commitment: &PedersenCommitment, nsk: &[u8]) -> Vec<u8> {
+    let mut input = pedersen_commitment.serialize().to_vec();
+    input.extend_from_slice(nsk);
+    hash(&input)
+}
+
+// Generate commitments for output UTXOs
+
+// uses the list of output_utxos[] and 
+// returns out_commitments[] where each out_commitments[i] = Commitment(output_utxos[i]) 
+// where the commitment will be determined
+pub fn generate_commitments(output_utxos: &[UTXO]) -> Vec<Vec<u8>> {
+    output_utxos
+        .iter()
+        .map(|utxo| {
+            let serialized = bincode::serialize(utxo).unwrap(); // Serialize UTXO.
+            hash(&serialized)
+        })
+        .collect()
+}
+