Rahul/move split secret (#4557)

* moving split secret to frost_utils

* removing unused import

* removing double &

* source code heading

ironfish-rust/src/frost_utils/mod.rs

@@ -3,3 +3,4 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 pub mod round_one;
+pub mod split_secret;

ironfish-rust/src/frost_utils/round_one.rs

@@ -17,13 +17,12 @@ pub fn round_one(key_package: &KeyPackage, seed: u64) -> (SigningNonces, Signing
 
 #[cfg(test)]
 mod test {
-
     use ff::Field;
     use ironfish_frost::frost::keys::IdentifierList;
     use jubjub::Fr;
     use rand::rngs::ThreadRng;
 
-    use crate::transaction::{split_secret, SecretShareConfig};
+    use crate::frost_utils::split_secret::{split_secret, SecretShareConfig};
 
     #[test]
     pub fn test_seed_provides_same_result() {

ironfish-rust/src/frost_utils/split_secret.rs

@@ -0,0 +1,90 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use ironfish_frost::frost;
+use ironfish_frost::frost::Error;
+use ironfish_frost::frost::{
+    keys::{IdentifierList, KeyPackage, PublicKeyPackage},
+    Identifier, SigningKey,
+};
+use rand::rngs::ThreadRng;
+use std::collections::HashMap;
+
+pub struct SecretShareConfig {
+    pub min_signers: u16,
+    pub max_signers: u16,
+    pub secret: Vec<u8>,
+}
+
+pub fn split_secret(
+    config: &SecretShareConfig,
+    identifiers: IdentifierList,
+    rng: &mut ThreadRng,
+) -> Result<(HashMap<Identifier, KeyPackage>, PublicKeyPackage), Error> {
+    let secret_key = SigningKey::deserialize(
+        config
+            .secret
+            .clone()
+            .try_into()
+            .map_err(|_| Error::MalformedSigningKey)?,
+    )?;
+
+    let (shares, pubkeys) = frost::keys::split(
+        &secret_key,
+        config.max_signers,
+        config.min_signers,
+        identifiers,
+        rng,
+    )?;
+
+    for (_k, v) in shares.clone() {
+        frost::keys::KeyPackage::try_from(v)?;
+    }
+
+    let mut key_packages: HashMap<_, _> = HashMap::new();
+
+    for (identifier, secret_share) in shares {
+        let key_package = frost::keys::KeyPackage::try_from(secret_share.clone()).unwrap();
+        key_packages.insert(identifier, key_package);
+    }
+
+    Ok((key_packages, pubkeys))
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::keys::SaplingKey;
+    use ironfish_frost::frost::{frost::keys::reconstruct, JubjubBlake2b512};
+
+    #[test]
+    fn test_split_secret() {
+        let mut rng = rand::thread_rng();
+
+        let key = SaplingKey::generate_key().spend_authorizing_key.to_bytes();
+
+        let config = SecretShareConfig {
+            min_signers: 2,
+            max_signers: 3,
+            secret: key.to_vec(),
+        };
+
+        let (key_packages, _) = split_secret(
+            &config,
+            ironfish_frost::frost::keys::IdentifierList::Default,
+            &mut rng,
+        )
+        .unwrap();
+        assert_eq!(key_packages.len(), 3);
+
+        let key_parts: Vec<_> = key_packages.values().cloned().collect();
+
+        let signing_key =
+            reconstruct::<JubjubBlake2b512>(&key_parts).expect("key reconstruction failed");
+
+        let scalar = signing_key.to_scalar();
+
+        assert_eq!(scalar.to_bytes(), key);
+    }
+}

ironfish-rust/src/transaction/mod.rs

@@ -21,17 +21,7 @@ use crate::{
     OutgoingViewKey, OutputDescription, SpendDescription, ViewKey,
 };
 
-use ironfish_frost::frost;
-use ironfish_frost::frost::Error;
-use rand::{
-    rngs::{OsRng, ThreadRng},
-    thread_rng,
-};
-
-use ironfish_frost::frost::{
-    keys::{IdentifierList, KeyPackage, PublicKeyPackage},
-    Identifier, SigningKey,
-};
+use rand::{rngs::OsRng, thread_rng};
 
 use bellperson::groth16::{verify_proofs_batch, PreparedVerifyingKey};
 use blake2b_simd::Params as Blake2b;
@@ -49,7 +39,6 @@ use ironfish_zkp::{
 };
 
 use std::{
-    collections::HashMap,
     io::{self, Write},
     iter,
     slice::Iter,
@@ -947,44 +936,3 @@ pub fn batch_verify_transactions<'a>(
         &SAPLING.mint_verifying_key,
     )
 }
-
-pub struct SecretShareConfig {
-    pub min_signers: u16,
-    pub max_signers: u16,
-    pub secret: Vec<u8>,
-}
-
-pub fn split_secret(
-    config: &SecretShareConfig,
-    identifiers: IdentifierList,
-    rng: &mut ThreadRng,
-) -> Result<(HashMap<Identifier, KeyPackage>, PublicKeyPackage), Error> {
-    let secret_key = SigningKey::deserialize(
-        config
-            .secret
-            .clone()
-            .try_into()
-            .map_err(|_| Error::MalformedSigningKey)?,
-    )?;
-
-    let (shares, pubkeys) = frost::keys::split(
-        &secret_key,
-        config.max_signers,
-        config.min_signers,
-        identifiers,
-        rng,
-    )?;
-
-    for (_k, v) in shares.clone() {
-        frost::keys::KeyPackage::try_from(v)?;
-    }
-
-    let mut key_packages: HashMap<_, _> = HashMap::new();
-
-    for (identifier, secret_share) in shares {
-        let key_package = frost::keys::KeyPackage::try_from(secret_share.clone()).unwrap();
-        key_packages.insert(identifier, key_package);
-    }
-
-    Ok((key_packages, pubkeys))
-}

ironfish-rust/src/transaction/tests.rs

@@ -14,14 +14,12 @@ use crate::{
     sapling_bls12::SAPLING,
     test_util::make_fake_witness,
     transaction::{
-        batch_verify_transactions, split_secret, verify_transaction, SecretShareConfig,
-        TransactionVersion, TRANSACTION_EXPIRATION_SIZE, TRANSACTION_FEE_SIZE,
-        TRANSACTION_SIGNATURE_SIZE,
+        batch_verify_transactions, verify_transaction, TransactionVersion,
+        TRANSACTION_EXPIRATION_SIZE, TRANSACTION_FEE_SIZE, TRANSACTION_SIGNATURE_SIZE,
     },
 };
 
 use ff::Field;
-use ironfish_frost::frost::{frost::keys::reconstruct, JubjubBlake2b512};
 use ironfish_zkp::{
     constants::{ASSET_ID_LENGTH, SPENDING_KEY_GENERATOR, TREE_DEPTH},
     proofs::{MintAsset, Output, Spend},
@@ -645,33 +643,3 @@ fn test_batch_verify() {
         Err(e) if matches!(e.kind, IronfishErrorKind::InvalidSpendSignature)
     ));
 }
-
-#[test]
-fn test_split_secret() {
-    let mut rng = rand::thread_rng();
-
-    let key = SaplingKey::generate_key().spend_authorizing_key.to_bytes();
-
-    let config = SecretShareConfig {
-        min_signers: 2,
-        max_signers: 3,
-        secret: key.to_vec(),
-    };
-
-    let (key_packages, _) = split_secret(
-        &config,
-        ironfish_frost::frost::keys::IdentifierList::Default,
-        &mut rng,
-    )
-    .unwrap();
-    assert_eq!(key_packages.len(), 3);
-
-    let key_parts: Vec<_> = key_packages.values().cloned().collect();
-
-    let signing_key =
-        reconstruct::<JubjubBlake2b512>(&key_parts).expect("key reconstruction failed");
-
-    let scalar = signing_key.to_scalar();
-
-    assert_eq!(scalar.to_bytes(), key);
-}