feat: zeroize

Dockerfile

@@ -0,0 +1,17 @@
+FROM rust:1.75 as base
+RUN cargo install cargo-chef --version ^0.1
+
+FROM base AS planner
+WORKDIR /app
+COPY . .
+RUN cargo chef prepare --recipe-path recipe.json
+
+FROM base as builder
+WORKDIR /app
+COPY --from=planner /app/recipe.json recipe.json
+RUN cargo chef cook --release --recipe-path recipe.json
+COPY . .
+RUN cargo build
+
+ENV WS_URL="ws://127.0.0.1:9944"
+CMD ["/bin/murmur"]

core/src/murmur.rs

@@ -25,6 +25,9 @@ use rand_chacha::ChaCha20Rng;
 use ark_std::rand::SeedableRng;
 use ark_std::rand::{CryptoRng, Rng};
 
+#[cfg(feature = "client")]
+use zeroize::Zeroize;
+
 #[cfg(feature = "client")]
 use ark_serialize::CanonicalSerialize;
 
@@ -78,12 +81,13 @@ impl MurmurStore {
     /// * `round_public_key`: The IDN beacon's public key
     ///
     pub fn new<E: EngineBLS, I: IdentityBuilder<BlockNumber>>(
-        seed: Vec<u8>,
+        mut seed: Vec<u8>,
         block_schedule: Vec<BlockNumber>,
-        ephemeral_msk: [u8; 32],
+        mut ephemeral_msk: [u8; 32],
         round_public_key: DoublePublicKey<E>,
     ) -> Result<Self, Error> {
-        let totp = build_generator(&seed.clone())?;
+        let totp = build_generator(seed.clone())?;
+        seed.zeroize();
         let mut metadata = BTreeMap::new();
 
         let store = MemStore::default();
@@ -114,6 +118,7 @@ impl MurmurStore {
             metadata.insert(*i, ct_bytes);
         }
 
+        ephemeral_msk.zeroize();
         let root = mmr.get_root().map_err(|_| Error::InconsistentStore)?;
 
         Ok(MurmurStore { metadata, root })
@@ -127,12 +132,13 @@ impl MurmurStore {
     ///
     pub fn execute(
         &self,
-        seed: Vec<u8>,
+        mut seed: Vec<u8>,
         when: BlockNumber,
         call_data: Vec<u8>,
     ) -> Result<(MerkleProof<Leaf, MergeLeaves>, Vec<u8>, Ciphertext, u64), Error> {
         if let Some(ciphertext) = self.metadata.get(&when) {
             let commitment = MurmurStore::commit(seed.clone(), when, &call_data.clone())?;
+            seed.zeroize();
             let idx = get_key_index(&self.metadata, &when)
                 .expect("The key must exist within the metadata.");
             let pos = leaf_index_to_pos(idx as u64);
@@ -152,8 +158,9 @@ impl MurmurStore {
     /// * `when`: The block number when the commitment is verifiable
     /// * `data`: The data to commit to
     ///
-    fn commit(seed: Vec<u8>, when: BlockNumber, data: &[u8]) -> Result<Vec<u8>, Error> {
-        let botp = build_generator(&seed)?;
+    fn commit(mut seed: Vec<u8>, when: BlockNumber, data: &[u8]) -> Result<Vec<u8>, Error> {
+        let botp = build_generator(seed.clone())?;
+        seed.zeroize();
         let otp_code = botp.generate(when);
 
         let mut hasher = sha3::Sha3_256::default();
@@ -198,9 +205,10 @@ pub fn timelock_encrypt<E: EngineBLS, R: CryptoRng + Rng + Sized>(
 
 /// Build a block-otp generator from the seed
 #[cfg(feature = "client")]
-fn build_generator(seed: &[u8]) -> Result<BOTPGenerator, Error> {
+fn build_generator(mut seed: Vec<u8>) -> Result<BOTPGenerator, Error> {
     let mut hasher = sha3::Sha3_256::default();
-    hasher.update(seed);
+    hasher.update(&seed);
+    seed.zeroize();
     let hash = hasher.finalize();
     BOTPGenerator::new(hash.to_vec())
         .map_err(|_| Error::InvalidSeed)
@@ -318,7 +326,7 @@ mod tests {
 
         // in practice, the otp code would be timelock decrypted
         // but for testing purposes, we will just calculate the expected one now
-        let botp = build_generator(&seed.clone()).unwrap();
+        let botp = build_generator(seed.clone()).unwrap();
         let otp_code = botp.generate(when);
 
         assert!(verify(
@@ -396,7 +404,7 @@ mod tests {
 
         // in practice, the otp code would be timelock decrypted
         // but for testing purposes, we will just calculate the expected one now
-        let botp = build_generator(&seed.clone()).unwrap();
+        let botp = build_generator(seed.clone()).unwrap();
         let otp_code = botp.generate(when);
 
         let bad_aux = vec![2, 3, 13, 3];
@@ -456,7 +464,7 @@ mod tests {
 
         // in practice, the otp code would be timelock decrypted
         // but for testing purposes, we will just calculate the expected one now
-        let botp = build_generator(&seed.clone()).unwrap();
+        let botp = build_generator(seed.clone()).unwrap();
         let otp_code = botp.generate(when);
         assert!(!verify(
             root,

lib/Cargo.toml

@@ -36,6 +36,8 @@ ark-ff = "0.4.0"
 ark-serialize = "0.4.0"
 w3f-bls = "0.1.3"
 murmur-core = { path = "../core/", features = ["client"] }
+zeroize = "1.8.1"
+
 
 [dev-dependencies]
 murmur-test-utils = { path = "../test-utils/" }

lib/src/bin/murmur/main.rs

@@ -64,8 +64,8 @@ struct WalletExecuteDetails {
     seed: String,
     #[arg(long, short)]
     to: String,
-    #[arg(short, long)]
-    amount: String
+    #[arg(short, long, value_parser = clap::value_parser!(u128))]
+    amount: u128
 }
 
 #[derive(Error, Debug)]
@@ -133,16 +133,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             let from_ss58_sized: [u8;32] = bytes.try_into()
                 .map_err(|_| CLIError::InvalidRecipient)?;
             let to = subxt::utils::AccountId32::from(from_ss58_sized);
-            let v: u128 = args.amount
-                .split_whitespace()
-                .map(|r| r.replace('_', "")
-                    .parse()
-                    .unwrap()
-            ).collect::<Vec<_>>()[0];
 
             let balance_transfer_call = Balances(etf::balances::Call::transfer_allow_death {
                 dest: subxt::utils::MultiAddress::<_, u32>::from(to),
-                value: v,
+                value: args.amount,
             });
 
             let store: MurmurStore = load_mmr_store(MMR_STORE_FILEPATH)?;

lib/src/lib.rs

@@ -30,7 +30,7 @@ use subxt::{
     config::SubstrateConfig, 
     ext::codec::Encode,
 };
-
+use zeroize::Zeroize;
 use w3f_bls::{DoublePublicKey, SerializableToBytes, TinyBLS377};
 
 // Generate an interface that we can use from the node's metadata.
@@ -62,8 +62,8 @@ impl IdentityBuilder<BlockNumber> for BasicIdBuilder {
 ///
 pub fn create(
     name: Vec<u8>,
-    seed: Vec<u8>,
-    ephem_msk: [u8; 32],
+    mut seed: Vec<u8>,
+    mut ephem_msk: [u8; 32],
     block_schedule: Vec<BlockNumber>,
     round_pubkey_bytes: Vec<u8>,
 ) -> Result<(subxt::tx::Payload<Create>, MurmurStore), Error> {
@@ -75,6 +75,8 @@ pub fn create(
         ephem_msk,
         round_pubkey,
     )?;
+    ephem_msk.zeroize();
+    seed.zeroize();
     let root = mmr_store.root.clone();
 
     let call = etf::tx()
@@ -101,12 +103,13 @@ pub fn create(
 ///
 pub fn prepare_execute(
     name: Vec<u8>,
-    seed: Vec<u8>,
+    mut seed: Vec<u8>,
     when: BlockNumber,
     store: MurmurStore,
     call: RuntimeCall,
 ) -> Result<subxt::tx::Payload<Proxy>, Error> {
     let (proof, commitment, ciphertext, pos) = store.execute(seed.clone(), when, call.encode())?;
+    seed.zeroize();
     let size = proof.mmr_size();
     let proof_items: Vec<Vec<u8>> = proof
         .proof_items()