Additional DKG Fixes

common/dkg/Cargo.toml

@@ -17,7 +17,6 @@ nym-contracts-common = { path = "../cosmwasm-smart-contracts/contracts-common",
 bs58 = { workspace = true }
 
 
-lazy_static = { workspace = true }
 rand = { workspace = true }
 rand_chacha = { workspace = true }
 rand_core = { workspace = true }

common/dkg/src/bte/encryption.rs

@@ -2,7 +2,10 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use crate::bte::keys::{DecryptionKey, PublicKey};
-use crate::bte::{evaluate_f, Params, CHUNK_SIZE, G2_GENERATOR_PREPARED, NUM_CHUNKS, PAIRING_BASE};
+use crate::bte::{
+    evaluate_f, precompute_g2_generator_prepared, precompute_pairing_base, Params, CHUNK_SIZE,
+    NUM_CHUNKS,
+};
 use crate::error::DkgError;
 use crate::utils::{combine_g1_chunks, combine_scalar_chunks, deserialize_g1, deserialize_g2};
 use crate::{Chunk, ChunkedShare, Share};
@@ -13,9 +16,9 @@ use rand::CryptoRng;
 use rand_core::RngCore;
 use std::collections::HashMap;
 use std::ops::Neg;
-use zeroize::Zeroize;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct Ciphertexts {
     pub rr: [G1Projective; NUM_CHUNKS],
     pub ss: [G1Projective; NUM_CHUNKS],
@@ -164,8 +167,7 @@ impl Ciphertexts {
     }
 }
 
-#[derive(Zeroize)]
-#[zeroize(drop)]
+#[derive(Zeroize, ZeroizeOnDrop)]
 /// Randomness generated during ciphertext generation that is required for proofs of knowledge.
 ///
 /// It must be handled with extreme care as its misuse might help malicious parties to recover
@@ -296,14 +298,14 @@ pub fn decrypt_share(
         let cc_ij = &ciphertext.ciphertext_chunks[i][j];
 
         let miller = bls12_381::multi_miller_loop(&[
-            (&cc_ij.to_affine(), &G2_GENERATOR_PREPARED),
+            (&cc_ij.to_affine(), &precompute_g2_generator_prepared()),
             (&rr_j.to_affine(), &G2Prepared::from(b_neg)),
             (&dk.a.to_affine(), &G2Prepared::from(zz_j)),
             (&ss_j.to_affine(), &G2Prepared::from(e_neg)),
         ]);
         let m = miller.final_exponentiation();
 
-        plaintext.chunks[j] = baby_step_giant_step(&m, &PAIRING_BASE, lookup_table)?;
+        plaintext.chunks[j] = baby_step_giant_step(&m, &precompute_pairing_base(), lookup_table)?;
     }
 
     plaintext.try_into()
@@ -363,7 +365,7 @@ impl BabyStepGiantStepLookup {
 
 impl Default for BabyStepGiantStepLookup {
     fn default() -> Self {
-        BabyStepGiantStepLookup::precompute(&PAIRING_BASE)
+        BabyStepGiantStepLookup::precompute(&precompute_pairing_base())
     }
 }
 
@@ -399,7 +401,7 @@ pub fn baby_step_giant_step(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::bte::{keygen, setup, DEFAULT_BSGS_TABLE};
+    use crate::bte::{encryption, keygen, setup};
     use rand_core::SeedableRng;
 
     fn verify_hazmat_rand(ciphertext: &Ciphertexts, randomness: &HazmatRandomness) {
@@ -457,7 +459,7 @@ mod tests {
         let (decryption_key1, public_key1) = keygen(&params, &mut rng);
         let (decryption_key2, public_key2) = keygen(&params, &mut rng);
 
-        let lookup_table = &DEFAULT_BSGS_TABLE;
+        let lookup_table = encryption::BabyStepGiantStepLookup::default();
 
         for _ in 0..10 {
             let m1 = Share::random(&mut rng);
@@ -472,15 +474,15 @@ mod tests {
                 &decryption_key1,
                 0,
                 &ciphertext,
-                Some(lookup_table),
+                Some(&lookup_table),
             )
             .unwrap();
             let recovered2 = decrypt_share(
                 &params,
                 &decryption_key2,
                 1,
                 &ciphertext,
-                Some(lookup_table),
+                Some(&lookup_table),
             )
             .unwrap();
             assert_eq!(m1, recovered1);
@@ -498,7 +500,7 @@ mod tests {
         let (decryption_key1, public_key1) = keygen(&params, &mut rng);
         let (decryption_key2, public_key2) = keygen(&params, &mut rng);
 
-        let lookup_table = &DEFAULT_BSGS_TABLE;
+        let lookup_table = encryption::BabyStepGiantStepLookup::default();
 
         for _ in 0..10 {
             let m1 = Share::random(&mut rng);
@@ -513,15 +515,15 @@ mod tests {
                 &decryption_key1,
                 0,
                 &ciphertext,
-                Some(lookup_table),
+                Some(&lookup_table),
             )
             .unwrap();
             let recovered2 = decrypt_share(
                 &params,
                 &decryption_key2,
                 1,
                 &ciphertext,
-                Some(lookup_table),
+                Some(&lookup_table),
             )
             .unwrap();
             assert_eq!(m1, recovered1);

common/dkg/src/bte/keys.rs

@@ -11,7 +11,7 @@ use group::GroupEncoding;
 use nym_pemstore::traits::{PemStorableKey, PemStorableKeyPair};
 use rand::CryptoRng;
 use rand_core::RngCore;
-use zeroize::Zeroize;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 // produces public key and a decryption key for the root of the tree
 pub fn keygen(
@@ -48,7 +48,7 @@ pub fn keygen(
     (dk, key_with_proof)
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Zeroize)]
 pub struct PublicKey(pub(crate) G1Projective);
 
 impl PublicKey {
@@ -57,7 +57,7 @@ impl PublicKey {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct PublicKeyWithProof {
     pub(crate) key: PublicKey,
     pub(crate) proof: ProofOfDiscreteLog,
@@ -136,8 +136,7 @@ impl PublicKeyWithProof {
     }
 }
 
-#[derive(Debug, Zeroize)]
-#[zeroize(drop)]
+#[derive(Debug, Zeroize, ZeroizeOnDrop)]
 #[cfg_attr(test, derive(PartialEq, Eq))]
 pub struct DecryptionKey {
     // g1^rho
@@ -242,6 +241,7 @@ impl DecryptionKey {
     }
 }
 
+#[derive(Zeroize, ZeroizeOnDrop)]
 pub struct KeyPair {
     pub(crate) private_key: DecryptionKey,
     pub(crate) public_key: PublicKeyWithProof,

common/dkg/src/bte/mod.rs

@@ -5,7 +5,6 @@ use crate::utils::hash_g2;
 use crate::{Chunk, Share};
 use bls12_381::{G1Affine, G2Affine, G2Prepared, G2Projective, Gt};
 use group::Curve;
-use lazy_static::lazy_static;
 
 pub mod encryption;
 pub mod keys;
@@ -16,13 +15,11 @@ pub mod proof_sharing;
 pub use encryption::{decrypt_share, encrypt_shares, Ciphertexts};
 pub use keys::{keygen, DecryptionKey, PublicKey, PublicKeyWithProof};
 
-lazy_static! {
-    pub(crate) static ref PAIRING_BASE: Gt =
-        bls12_381::pairing(&G1Affine::generator(), &G2Affine::generator());
-    pub(crate) static ref G2_GENERATOR_PREPARED: G2Prepared =
-        G2Prepared::from(G2Affine::generator());
-    pub(crate) static ref DEFAULT_BSGS_TABLE: encryption::BabyStepGiantStepLookup =
-        encryption::BabyStepGiantStepLookup::default();
+pub(crate) fn precompute_pairing_base() -> Gt {
+    bls12_381::pairing(&G1Affine::generator(), &G2Affine::generator())
+}
+pub(crate) fn precompute_g2_generator_prepared() -> G2Prepared {
+    G2Prepared::from(G2Affine::generator())
 }
 
 // Domain tries to follow guidelines specified by:

common/dkg/src/bte/proof_chunking.rs

@@ -12,6 +12,7 @@ use ff::Field;
 use group::{Group, GroupEncoding};
 use rand::{CryptoRng, Rng};
 use rand_core::{RngCore, SeedableRng};
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 const CHUNKING_ORACLE_DOMAIN: &[u8] =
     b"NYM_COCONUT_NIDKG_V01_CS01_SHA-256_CHACHA20_CHUNKING_ORACLE";
@@ -67,7 +68,7 @@ impl<'a> Instance<'a> {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct ProofOfChunking {
     y0: G1Projective,
     bb: Vec<G1Projective>,

common/dkg/src/bte/proof_discrete_log.rs

@@ -7,14 +7,14 @@ use ff::Field;
 use group::GroupEncoding;
 use rand::CryptoRng;
 use rand_core::RngCore;
-use zeroize::Zeroize;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 // Domain tries to follow guidelines specified by:
 // https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-11#section-3.1
 const DISCRETE_LOG_DOMAIN: &[u8] =
     b"NYM_COCONUT_NIDKG_V01_CS01_WITH_BLS12381_XMD:SHA-256_SSWU_RO_PROOF_DISCRETE_LOG";
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct ProofOfDiscreteLog {
     pub(crate) rand_commitment: G1Projective,
     pub(crate) response: Scalar,
@@ -52,9 +52,9 @@ impl ProofOfDiscreteLog {
         let public_bytes = public.to_bytes();
         let rand_commit_bytes = rand_commit.to_bytes();
 
-        let mut bytes = Vec::with_capacity(96);
-        bytes.extend_from_slice(public_bytes.as_ref());
-        bytes.extend_from_slice(rand_commit_bytes.as_ref());
+        let mut bytes = [0u8; 96];
+        bytes[0..48].copy_from_slice(public_bytes.as_ref());
+        bytes[48..96].copy_from_slice(rand_commit_bytes.as_ref());
 
         hash_to_scalar(bytes, DISCRETE_LOG_DOMAIN)
     }

common/dkg/src/bte/proof_sharing.rs

@@ -12,6 +12,7 @@ use group::GroupEncoding;
 use rand::CryptoRng;
 use rand_core::RngCore;
 use std::collections::BTreeMap;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 // Domain tries to follow guidelines specified by:
 // https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-11#section-3.1
@@ -77,7 +78,7 @@ impl<'a> Instance<'a> {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct ProofOfSecretSharing {
     ff: G1Projective,
     aa: G2Projective,

common/dkg/src/dealing.rs

@@ -18,7 +18,7 @@ use rand_core::RngCore;
 use std::collections::BTreeMap;
 use zeroize::Zeroize;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Zeroize)]
 #[cfg_attr(test, derive(PartialEq, Eq))]
 pub struct RecoveredVerificationKeys {
     pub recovered_master: G2Projective,
@@ -83,7 +83,7 @@ impl RecoveredVerificationKeys {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Zeroize)]
 pub struct Dealing {
     pub public_coefficients: PublicCoefficients,
     pub ciphertexts: Ciphertexts,

common/dkg/src/interpolation/polynomial.rs

@@ -9,9 +9,9 @@ use group::GroupEncoding;
 use rand::CryptoRng;
 use rand_core::RngCore;
 use std::ops::{Add, Index, IndexMut};
-use zeroize::Zeroize;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct PublicCoefficients {
     pub(crate) coefficients: Vec<G2Projective>,
 }
@@ -111,8 +111,7 @@ impl IndexMut<usize> for PublicCoefficients {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Zeroize)]
-#[zeroize(drop)]
+#[derive(Clone, Debug, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct Polynomial {
     coefficients: Vec<Scalar>,
 }

common/dkg/src/share.rs

@@ -6,14 +6,13 @@ use crate::error::DkgError;
 use crate::interpolation::perform_lagrangian_interpolation_at_origin;
 use crate::NodeIndex;
 use bls12_381::Scalar;
-use zeroize::Zeroize;
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 // if this type is changed, one must ensure all values can fit in it
 pub type Chunk = u16;
 
-#[derive(PartialEq, Eq, Debug, Zeroize)]
+#[derive(PartialEq, Eq, Debug, Zeroize, ZeroizeOnDrop)]
 #[cfg_attr(test, derive(Clone))]
-#[zeroize(drop)]
 pub struct Share(pub(crate) Scalar);
 
 pub fn combine_shares(shares: Vec<Share>, node_indices: &[NodeIndex]) -> Result<Scalar, DkgError> {
@@ -66,9 +65,8 @@ impl From<Scalar> for Share {
     }
 }
 
-#[derive(Default, Zeroize)]
+#[derive(Default, Zeroize, ZeroizeOnDrop)]
 #[cfg_attr(test, derive(Clone))]
-#[zeroize(drop)]
 pub(crate) struct ChunkedShare {
     pub(crate) chunks: [Chunk; NUM_CHUNKS],
 }