From 08bb00cc8f18f9e20f3561db968739136898b8e5 Mon Sep 17 00:00:00 2001
From: Paul Miller <paul@paulmillr.com>
Date: Tue, 8 Aug 2023 13:43:14 +0000
Subject: [PATCH] poseidon: prohibit sBoxPower other than 3, 5, 7

---
 src/abstract/poseidon.ts | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/abstract/poseidon.ts b/src/abstract/poseidon.ts
index 38ab17d..322732e 100644
--- a/src/abstract/poseidon.ts
+++ b/src/abstract/poseidon.ts
@@ -21,12 +21,13 @@ export function validateOpts(opts: PoseidonOpts) {
     if (typeof opts[i] !== 'number' || !Number.isSafeInteger(opts[i]))
       throw new Error(`Poseidon: invalid param ${i}=${opts[i]} (${typeof opts[i]})`);
   }
-  if (opts.reversePartialPowIdx !== undefined && typeof opts.reversePartialPowIdx !== 'boolean')
-    throw new Error(`Poseidon: invalid param reversePartialPowIdx=${opts.reversePartialPowIdx}`);
-  // Default is 5, but by some reasons stark uses 3
-  let sboxPower = opts.sboxPower;
+  const rev = opts.reversePartialPowIdx;
+  if (rev !== undefined && typeof rev !== 'boolean')
+    throw new Error(`Poseidon: invalid param reversePartialPowIdx=${rev}`);
+  // Default is 5, but for some reasons stark uses 3
+  let { sboxPower } = opts;
   if (sboxPower === undefined) sboxPower = 5;
-  if (typeof sboxPower !== 'number' || !Number.isSafeInteger(sboxPower))
+  if (!([3, 5, 7].includes(sboxPower)))
     throw new Error(`Poseidon wrong sboxPower=${sboxPower}`);
 
   const _sboxPower = BigInt(sboxPower);