daod added forgotten file util.rs

bin/daod/src/util.rs

@@ -0,0 +1,7 @@
+use halo2_gadgets::poseidon::primitives as poseidon;
+use pasta_curves::pallas;
+
+pub fn poseidon_hash<const N: usize>(messages: [pallas::Base; N]) -> pallas::Base {
+    poseidon::Hash::<_, poseidon::P128Pow5T3, poseidon::ConstantLength<N>, 3, 2>::init()
+        .hash(messages)
+}