From 97177eaa3cf9a1f9d508b3ee1c92e7d0d43e1e20 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Fri, 9 Feb 2024 01:42:34 +0000
Subject: [PATCH] feat(avm): hashing to simulator

---
 avm-transpiler/src/transpile.rs               | 35 ++++++++++++++++++-
 .../contracts/avm_test_contract/src/main.nr   | 10 ++++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/avm-transpiler/src/transpile.rs b/avm-transpiler/src/transpile.rs
index 62dceb654c66..48b63297d212 100644
--- a/avm-transpiler/src/transpile.rs
+++ b/avm-transpiler/src/transpile.rs
@@ -1,7 +1,7 @@
 use acvm::acir::brillig::Opcode as BrilligOpcode;
 use acvm::acir::circuit::brillig::Brillig;
 
-use acvm::brillig_vm::brillig::{BinaryFieldOp, BinaryIntOp, ValueOrArray};
+use acvm::brillig_vm::brillig::{BinaryFieldOp, BinaryIntOp, BlackBoxOp, ValueOrArray};
 
 use crate::instructions::{
     AvmInstruction, AvmOperand, AvmTypeTag, FIRST_OPERAND_INDIRECT, ZEROTH_OPERAND_INDIRECT,
@@ -256,6 +256,7 @@ pub fn brillig_to_avm(brillig: &Brillig) -> Vec<u8> {
             BrilligOpcode::ForeignCall { function, destinations, inputs, destination_value_types:_, input_value_types:_ } => {
                 handle_foreign_call(&mut avm_instrs, function, destinations, inputs);
             },
+            BrilligOpcode::BlackBox(operation) => handle_black_box_function(&mut avm_instrs, operation),
             _ => panic!(
                 "Transpiler doesn't know how to process {:?} brillig instruction",
                 brillig_instr
@@ -321,6 +322,38 @@ fn handle_foreign_call(
     });
 }
 
+fn handle_black_box_function(avm_instrs: &mut Vec<AvmInstruction>, operation: &BlackBoxOp) {
+    match operation {
+        BlackBoxOp::Keccak256 { message, output } => {
+            // For the meantime, we output keccak as 32 u8s
+            let hash_offset = message.pointer.0;
+            let hash_size = message.size.0;
+
+            let out_offset = output.pointer.0;
+            let out_size = output.size;
+            assert!(out_size == 32);
+
+            avm_instrs.push(AvmInstruction {
+                opcode: AvmOpcode::KECCAK,
+                operands: vec![AvmOperand::U32 {
+                    value: hash_offset as u32,
+                },
+                AvmOperand::U32 {
+                    value: hash_size as u32,
+                },
+                AvmOperand::U32 {
+                    value: out_offset as u32,
+                }],
+                ..Default::default()
+            });
+        },
+        _ => panic!(
+            "Transpiler doesn't know how to process BlackBoxOp {:?}",
+            operation
+        ),
+    }
+}
+
 /// Compute an array that maps each Brillig pc to an AVM pc.
 /// This must be done before transpiling to properly transpile jump destinations.
 /// This is necessary for two reasons:
diff --git a/yarn-project/noir-contracts/contracts/avm_test_contract/src/main.nr b/yarn-project/noir-contracts/contracts/avm_test_contract/src/main.nr
index 405432acb7cb..97b59ee22cee 100644
--- a/yarn-project/noir-contracts/contracts/avm_test_contract/src/main.nr
+++ b/yarn-project/noir-contracts/contracts/avm_test_contract/src/main.nr
@@ -19,6 +19,16 @@ contract AvmTest {
         argA + argB
     }
 
+    /************************************************************************
+     * Hashing functions
+     ************************************************************************/
+    #[aztec(public-vm)]
+    fn oneFieldKeccak(data: [u8; 32]) -> pub Field {
+        // let data_as_bytes = data.to_be_bytes(32);
+        let output = dep::std::hash::keccak256(data, 32);
+        output[0] as Field
+    }
+
     /************************************************************************
      * AvmContext functions
      ************************************************************************/