From d696535da5b3fc6a5657e855fc7ffa008abfdc95 Mon Sep 17 00:00:00 2001
From: aniampio <anna.piotrowska.15@ucl.ac.uk>
Date: Thu, 14 Jul 2022 23:33:15 +0100
Subject: [PATCH] Add duplicate payinfo check for identify

---
 .../src/scheme/identify.rs                    | 18 +++++++++++----
 .../src/scheme/keygen.rs                      | 12 +++++-----
 .../src/scheme/mod.rs                         |  2 +-
 .../src/tests/e2e.rs                          | 23 -------------------
 4 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/common/nym_offline_compact_ecash/src/scheme/identify.rs b/common/nym_offline_compact_ecash/src/scheme/identify.rs
index 74a9f8d105..629612ae55 100644
--- a/common/nym_offline_compact_ecash/src/scheme/identify.rs
+++ b/common/nym_offline_compact_ecash/src/scheme/identify.rs
@@ -3,11 +3,11 @@ use crate::PayInfo;
 use crate::scheme::keygen::PublicKeyUser;
 use crate::scheme::Payment;
 
+#[derive(Debug, Eq, PartialEq)]
 pub enum IdentifyResult {
     NotADuplicatePayment,
     DuplicatePayInfo(PayInfo),
     DoubleSpendingPublicKeys(PublicKeyUser),
-
 }
 
 pub fn identify(pay1: Payment, pay2: Payment, pay_info1: PayInfo, pay_info2: PayInfo) -> Result<IdentifyResult> {
@@ -43,6 +43,7 @@ mod tests {
     use itertools::izip;
 
     use crate::{aggregate_verification_keys, aggregate_wallets, generate_keypair_user, issue_verify, issue_wallet, PartialWallet, PayInfo, ttp_keygen, VerificationKeyAuth, withdrawal_request};
+    use crate::scheme::identify::{identify, IdentifyResult};
     use crate::scheme::setup::setup;
 
     #[test]
@@ -90,20 +91,29 @@ mod tests {
         ).unwrap();
 
         // Let's try to spend some coins
-        let pay_info = PayInfo { info: [6u8; 32] };
+        let pay_info1 = PayInfo { info: [6u8; 32] };
         let spend_vv = 1;
 
         let (payment1, upd_wallet) = aggr_wallet.spend(
             &params,
             &verification_key,
             &user_keypair.secret_key(),
-            &pay_info,
+            &pay_info1,
             false,
             spend_vv,
         ).unwrap();
 
         assert!(payment1
-            .spend_verify(&params, &verification_key, &pay_info, spend_vv)
+            .spend_verify(&params, &verification_key, &pay_info1, spend_vv)
             .unwrap());
+
+        let payment2 = payment1.clone();
+        assert!(payment2
+            .spend_verify(&params, &verification_key, &pay_info1, spend_vv)
+            .unwrap());
+
+        let pay_info2 = pay_info1.clone();
+        let identify_result = identify(payment1, payment2, pay_info1.clone(), pay_info2.clone()).unwrap();
+        assert_eq!(identify_result, IdentifyResult::DuplicatePayInfo(pay_info1.clone()));
     }
 }
\ No newline at end of file
diff --git a/common/nym_offline_compact_ecash/src/scheme/keygen.rs b/common/nym_offline_compact_ecash/src/scheme/keygen.rs
index d0c62db429..3f57599d24 100644
--- a/common/nym_offline_compact_ecash/src/scheme/keygen.rs
+++ b/common/nym_offline_compact_ecash/src/scheme/keygen.rs
@@ -11,11 +11,11 @@ use crate::error::{CompactEcashError, Result};
 use crate::scheme::aggregation::aggregate_verification_keys;
 use crate::scheme::setup::GroupParameters;
 use crate::scheme::SignerIndex;
-use crate::utils::Polynomial;
 use crate::utils::{
     try_deserialize_g1_projective, try_deserialize_g2_projective, try_deserialize_scalar,
     try_deserialize_scalar_vec,
 };
+use crate::utils::Polynomial;
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct SecretKeyAuth {
@@ -242,13 +242,13 @@ impl<'a> Mul<Scalar> for &'a VerificationKeyAuth {
 }
 
 impl<T> Sum<T> for VerificationKeyAuth
-where
-    T: Borrow<VerificationKeyAuth>,
+    where
+        T: Borrow<VerificationKeyAuth>,
 {
     #[inline]
     fn sum<I>(iter: I) -> Self
-    where
-        I: Iterator<Item = T>,
+        where
+            I: Iterator<Item=T>,
     {
         let mut peekable = iter.peekable();
         let head_attributes = match peekable.peek() {
@@ -332,7 +332,7 @@ impl SecretKeyUser {
     }
 }
 
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Debug, Eq, PartialEq, Clone)]
 pub struct PublicKeyUser {
     pub(crate) pk: G1Projective,
 }
diff --git a/common/nym_offline_compact_ecash/src/scheme/mod.rs b/common/nym_offline_compact_ecash/src/scheme/mod.rs
index 35d6e09013..31e8188d49 100644
--- a/common/nym_offline_compact_ecash/src/scheme/mod.rs
+++ b/common/nym_offline_compact_ecash/src/scheme/mod.rs
@@ -253,7 +253,7 @@ pub fn compute_kappa(
         .sum::<G2Projective>()
 }
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Eq, Debug, Clone)]
 pub struct PayInfo {
     pub info: [u8; 32],
 }
diff --git a/common/nym_offline_compact_ecash/src/tests/e2e.rs b/common/nym_offline_compact_ecash/src/tests/e2e.rs
index ad4fa99705..528faa9974 100644
--- a/common/nym_offline_compact_ecash/src/tests/e2e.rs
+++ b/common/nym_offline_compact_ecash/src/tests/e2e.rs
@@ -75,29 +75,6 @@ fn main() -> Result<(), CompactEcashError> {
         .spend_verify(&params, &verification_key, &pay_info, spend_vv)
         .unwrap());
 
-    // try to spend twice the same payment with different payInfo
-    let payment1 = payment.clone();
-    let pay_info2 = PayInfo { info: [9u8; 32] };
-    let rr2 = hash_to_scalar(pay_info2.info);
-    let l2 = aggr_wallet.l() - 1;
-    let payment2 = Payment {
-        kappa: payment1.kappa.clone(),
-        sig: payment1.sig.clone(),
-        ss: payment1.ss.clone(),
-        tt: vec![grparams.gen1() * user_keypair.secret_key().sk
-            + pseudorandom_fgt(&grparams, aggr_wallet.t(), l2) * rr2],
-        aa: payment1.aa.clone(),
-        cc: payment1.cc.clone(),
-        dd: payment1.dd.clone(),
-        rr: vec![rr2],
-        kappa_k: payment1.kappa_k.clone(),
-        sig_lk: payment1.sig_lk.clone(),
-        zk_proof: payment1.zk_proof.clone(),
-        vv: spend_vv,
-    };
-
-    let identified_user = identify(payment1, payment2, pay_info, pay_info2).unwrap();
-    // assert_eq!(user_keypair.public_key().pk, identified_user.pk);
 
     Ok(())
 }