From 73ef0f8c0871c16f71d6f3e40fb3402a47585615 Mon Sep 17 00:00:00 2001
From: Ben Savage <btsavage@fb.com>
Date: Thu, 28 Mar 2024 13:19:06 +0800
Subject: [PATCH] clippy

---
 .../ipa_prf/malicious_security/hashing.rs        | 14 ++++++++++++--
 .../ipa_prf/malicious_security/prover.rs         | 16 ++++++++--------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/ipa-core/src/protocol/ipa_prf/malicious_security/hashing.rs b/ipa-core/src/protocol/ipa_prf/malicious_security/hashing.rs
index f91c881ac..4d490f318 100644
--- a/ipa-core/src/protocol/ipa_prf/malicious_security/hashing.rs
+++ b/ipa-core/src/protocol/ipa_prf/malicious_security/hashing.rs
@@ -115,8 +115,18 @@ mod test {
         );
 
         // swapping two elements should change the hash
-        let index_1 = rng.gen_range(0..LIST_LENGTH);
-        let index_2 = (index_1 + rng.gen_range(1..LIST_LENGTH)) % LIST_LENGTH;
+        let mut index_1 = 0;
+        let mut index_2 = 0;
+        // There is a 1 in 31 chance that these two elements are the exact same value.
+        // To make sure this doesn't become a flaky test, let's just pick two different
+        // elements to swap when that happens.
+        // This will be an infinite loop if all elements are the same. The chances of that
+        // are (1 / 31) ^ (LIST_LENGTH - 1)
+        // which is 1 in 923,521 when LIST_LENGTH is 5. I'm OK with that.
+        while list[index_1] == list[index_2] {
+            index_1 = rng.gen_range(0..LIST_LENGTH);
+            index_2 = (index_1 + rng.gen_range(1..LIST_LENGTH)) % LIST_LENGTH;
+        }
         list.swap(index_1, index_2);
 
         let hash_3 = compute_hash(&list);
diff --git a/ipa-core/src/protocol/ipa_prf/malicious_security/prover.rs b/ipa-core/src/protocol/ipa_prf/malicious_security/prover.rs
index b8c566bbb..175b3d977 100644
--- a/ipa-core/src/protocol/ipa_prf/malicious_security/prover.rs
+++ b/ipa-core/src/protocol/ipa_prf/malicious_security/prover.rs
@@ -46,7 +46,7 @@ pub type TwoNPlusOne<N> = Sum<Sum<N, N>, U1>;
 /// Distributed Zero Knowledge Proofs algorithm drawn from
 /// `https://eprint.iacr.org/2023/909.pdf`
 ///
-#[allow(non_camel_case_types)]
+#[allow(non_camel_case_types, clippy::many_single_char_names)]
 impl<F> ProofGenerator<F>
 where
     F: PrimeField,
@@ -57,8 +57,8 @@ where
     }
 
     pub fn gen_challenge_and_recurse<λ: ArrayLength, I, J>(
-        proof_left: GenericArray<F, TwoNMinusOne<λ>>,
-        proof_right: GenericArray<F, TwoNMinusOne<λ>>,
+        proof_left: &GenericArray<F, TwoNMinusOne<λ>>,
+        proof_right: &GenericArray<F, TwoNMinusOne<λ>>,
         u: I,
         v: J,
     ) -> ProofGenerator<F>
@@ -84,7 +84,7 @@ where
             "When the output is this small, you should validate the proof with a more straightforward reveal"
         );
 
-        let r: F = hash_to_field(&compute_hash(&proof_left), &compute_hash(&proof_right));
+        let r: F = hash_to_field(&compute_hash(proof_left), &compute_hash(proof_right));
         let mut p = GenericArray::<F, λ>::generate(|_| F::ZERO);
         let mut q = GenericArray::<F, λ>::generate(|_| F::ZERO);
         let denominator = CanonicalLagrangeDenominator::<F, λ>::new();
@@ -277,8 +277,8 @@ mod test {
 
         // fiat-shamir
         let pg_2 = ProofGenerator::gen_challenge_and_recurse::<U4, _, _>(
-            proof_left_1,
-            proof_right_1,
+            &proof_left_1,
+            &proof_right_1,
             U_1.into_iter().map(|x| Fp31::try_from(x).unwrap()),
             V_1.into_iter().map(|x| Fp31::try_from(x).unwrap()),
         );
@@ -302,8 +302,8 @@ mod test {
 
         // fiat-shamir
         let pg_3 = ProofGenerator::gen_challenge_and_recurse::<U4, _, _>(
-            proof_left_2,
-            proof_right_2,
+            &proof_left_2,
+            &proof_right_2,
             pg_2.u,
             pg_2.v,
         );