From e51fc42884b25727ab85a8d9027bfecf6a7d01fc Mon Sep 17 00:00:00 2001
From: Eli Margolin <31743392+ecmargo@users.noreply.github.com>
Date: Wed, 16 Oct 2024 18:15:07 -0400
Subject: [PATCH] Remove unneeded permute from Poseidon hashing (#152)

* removed unneeded permutes

* tests are consistent

* Apply suggestions from code review

* formatting

---------

Co-authored-by: Eli Margolin <elizabethmargolin@Elizabeths-MacBook-Pro.local>
Co-authored-by: Pratyush Mishra <pratyushmishra@berkeley.edu>
Co-authored-by: Eli Margolin <elizabethmargolin@ist-02748.apn.wlan.private.upenn.edu>
Co-authored-by: Pratyush Mishra <pratyush795@gmail.com>
Co-authored-by: Eli Margolin <elizabethmargolin@ist-12791.apn.wlan.private.upenn.edu>
---
 crypto-primitives/src/sponge/poseidon/constraints.rs | 1 -
 crypto-primitives/src/sponge/poseidon/mod.rs         | 1 -
 crypto-primitives/src/sponge/poseidon/tests.rs       | 3 ---
 3 files changed, 5 deletions(-)

diff --git a/crypto-primitives/src/sponge/poseidon/constraints.rs b/crypto-primitives/src/sponge/poseidon/constraints.rs
index a768a12..c3023ba 100644
--- a/crypto-primitives/src/sponge/poseidon/constraints.rs
+++ b/crypto-primitives/src/sponge/poseidon/constraints.rs
@@ -224,7 +224,6 @@ impl<F: PrimeField> CryptographicSpongeVar<F, PoseidonSponge<F>> for PoseidonSpo
             DuplexSpongeMode::Squeezing {
                 next_squeeze_index: _,
             } => {
-                self.permute()?;
                 self.absorb_internal(0, input.as_slice())?;
             }
         };
diff --git a/crypto-primitives/src/sponge/poseidon/mod.rs b/crypto-primitives/src/sponge/poseidon/mod.rs
index 7740001..471c162 100644
--- a/crypto-primitives/src/sponge/poseidon/mod.rs
+++ b/crypto-primitives/src/sponge/poseidon/mod.rs
@@ -251,7 +251,6 @@ impl<F: PrimeField> CryptographicSponge for PoseidonSponge<F> {
             DuplexSpongeMode::Squeezing {
                 next_squeeze_index: _,
             } => {
-                self.permute();
                 self.absorb_internal(0, elems.as_slice());
             }
         };
diff --git a/crypto-primitives/src/sponge/poseidon/tests.rs b/crypto-primitives/src/sponge/poseidon/tests.rs
index 73955d6..dd760d1 100644
--- a/crypto-primitives/src/sponge/poseidon/tests.rs
+++ b/crypto-primitives/src/sponge/poseidon/tests.rs
@@ -111,9 +111,6 @@ fn run_cross_test<F: PrimeField + Absorb>(cfg: &PoseidonConfig<F>) {
                 match self.mode() {
                     SpongeMode::Absorbing => self.absorbing.extend_from_slice(input),
                     SpongeMode::Squeezing => {
-                        // Wash the state as mode changes
-                        // This is not appied in SAFE sponge
-                        permute(&self.cfg, &mut self.state);
                         // Append inputs to the absorbing line
                         self.absorbing.extend_from_slice(input);
                         // Change mode to absorbing