From efd70f4b8bb284815c5345bd16d79018ed2dd812 Mon Sep 17 00:00:00 2001
From: Lasse Herskind <16536249+LHerskind@users.noreply.github.com>
Date: Wed, 28 Feb 2024 09:02:55 +0100
Subject: [PATCH] feat: AUTHWIT generator (#4798)

Fixes #2676 by using a different index for the pedersen hash.
---
 noir-projects/aztec-nr/authwit/src/auth.nr                | 8 ++++----
 .../src/crates/types/src/constants.nr                     | 1 +
 yarn-project/aztec.js/src/utils/authwit.ts                | 2 +-
 yarn-project/circuits.js/src/constants.gen.ts             | 1 +
 4 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/noir-projects/aztec-nr/authwit/src/auth.nr b/noir-projects/aztec-nr/authwit/src/auth.nr
index 99b07bf11a8..34af8aa8bf9 100644
--- a/noir-projects/aztec-nr/authwit/src/auth.nr
+++ b/noir-projects/aztec-nr/authwit/src/auth.nr
@@ -1,6 +1,6 @@
 use dep::aztec::protocol_types::{
     abis::function_selector::FunctionSelector, address::AztecAddress,
-    constants::{GENERATOR_INDEX__SIGNATURE_PAYLOAD}, hash::{hash_args, pedersen_hash}
+    constants::{GENERATOR_INDEX__AUTHWIT}, hash::{hash_args, pedersen_hash}
 };
 use dep::aztec::context::{PrivateContext, PublicContext, Context};
 
@@ -31,7 +31,7 @@ pub fn assert_current_call_valid_authwit(context: &mut PrivateContext, on_behalf
         [
         context.msg_sender().to_field(), context.this_address().to_field(), context.selector().to_field(), context.args_hash
     ],
-        GENERATOR_INDEX__SIGNATURE_PAYLOAD
+        GENERATOR_INDEX__AUTHWIT
     );
     assert_valid_authwit(context, on_behalf_of, message_hash);
 }
@@ -55,7 +55,7 @@ pub fn assert_current_call_valid_authwit_public(context: &mut PublicContext, on_
         [
         context.msg_sender().to_field(), context.this_address().to_field(), context.selector().to_field(), context.args_hash
     ],
-        GENERATOR_INDEX__SIGNATURE_PAYLOAD
+        GENERATOR_INDEX__AUTHWIT
     );
     assert_valid_authwit_public(context, on_behalf_of, message_hash);
 }
@@ -72,7 +72,7 @@ pub fn compute_authwit_message_hash<N>(
     let args_hash = hash_args(args);
     pedersen_hash(
         [caller.to_field(), target.to_field(), selector.to_field(), args_hash],
-        GENERATOR_INDEX__SIGNATURE_PAYLOAD
+        GENERATOR_INDEX__AUTHWIT
     )
 }
 // docs:end:compute_authwit_message_hash
diff --git a/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr b/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
index 690da1a59d5..49fcbd999bf 100644
--- a/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
+++ b/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
@@ -232,3 +232,4 @@ global GENERATOR_INDEX__VK = 41;
 global GENERATOR_INDEX__PRIVATE_CIRCUIT_PUBLIC_INPUTS = 42;
 global GENERATOR_INDEX__PUBLIC_CIRCUIT_PUBLIC_INPUTS = 43;
 global GENERATOR_INDEX__FUNCTION_ARGS = 44;
+global GENERATOR_INDEX__AUTHWIT = 45;
diff --git a/yarn-project/aztec.js/src/utils/authwit.ts b/yarn-project/aztec.js/src/utils/authwit.ts
index f449a429b2b..79898897e9a 100644
--- a/yarn-project/aztec.js/src/utils/authwit.ts
+++ b/yarn-project/aztec.js/src/utils/authwit.ts
@@ -18,7 +18,7 @@ export const computeAuthWitMessageHash = (caller: AztecAddress, request: Functio
       request.functionData.selector.toField(),
       PackedArguments.fromArgs(request.args).hash,
     ].map(fr => fr.toBuffer()),
-    GeneratorIndex.SIGNATURE_PAYLOAD,
+    GeneratorIndex.AUTHWIT,
   );
 };
 // docs:end:authwit_computeAuthWitMessageHash
diff --git a/yarn-project/circuits.js/src/constants.gen.ts b/yarn-project/circuits.js/src/constants.gen.ts
index 5213d7fe103..d4c77e327b6 100644
--- a/yarn-project/circuits.js/src/constants.gen.ts
+++ b/yarn-project/circuits.js/src/constants.gen.ts
@@ -145,4 +145,5 @@ export enum GeneratorIndex {
   PRIVATE_CIRCUIT_PUBLIC_INPUTS = 42,
   PUBLIC_CIRCUIT_PUBLIC_INPUTS = 43,
   FUNCTION_ARGS = 44,
+  AUTHWIT = 45,
 }