feat(public)!: reroute public calls to dispatch function

docs/docs/migration_notes.md

@@ -8,6 +8,12 @@ Aztec is in full-speed development. Literally every version breaks compatibility
 
 ## TBD
 
+### Changes to public calling convention
+
+Contracts that include public functions (that is, marked with `#[public]`), are required to have a function `public_dispatch(selector: Field)` which acts as an entry point. This will be soon the only public function registered/deployed in contracts. The calling convention is updated so that external calls are made to this function.
+
+If you are writing your contracts using Aztec-nr, there is nothing you need to change. The `public_dispatch` function is automatically generated by the `#[aztec]` macro.
+
 ### [Aztec.nr] Renamed `unsafe_rand` to `random`
 
 Since this is an `unconstrained` function, callers are already supposed to include an `unsafe` block, so this function has been renamed for reduced verbosity.
@@ -64,8 +70,8 @@ contract XYZ {
 
 -    numbers.at(owner).initialize(&mut new_number).emit(encode_and_encrypt_note_with_keys(&mut context, owner_ovpk_m, owner_ivpk_m, owner));
 +    numbers.at(owner).initialize(&mut new_number).emit(encode_and_encrypt_note(&mut context, owner_ovpk_m, owner_ivpk_m, owner));
-
 }
+```
 
 ## 0.56.0
 
@@ -208,6 +214,7 @@ export LOG_LEVEL="debug"
 - assert(verification == true);
 - true
 + std::ecdsa_secp256k1::verify_signature(public_key.x, public_key.y, signature, hashed_message)
+```
 
 ## 0.49.0
 
@@ -406,17 +413,16 @@ struct WithdrawalProcessed {
 
 ### [Aztec.nr] rename `encode_and_encrypt_with_keys` to `encode_and_encrypt_note_with_keys`
 
-````diff
+```diff
 contract XYZ {
 -   use dep::aztec::encrypted_logs::encrypted_note_emission::encode_and_encrypt_with_keys;
 +   use dep::aztec::encrypted_logs::encrypted_note_emission::encode_and_encrypt_note_with_keys;
 ....
 
 -    numbers.at(owner).initialize(&mut new_number).emit(encode_and_encrypt_with_keys(&mut context, owner_ovpk_m, owner_ivpk_m));
 +    numbers.at(owner).initialize(&mut new_number).emit(encode_and_encrypt_note_with_keys(&mut context, owner_ovpk_m, owner_ivpk_m));
-
 }
-
+```
 
 ### [Aztec.nr] changes to `NoteInterface`
 
@@ -469,7 +475,7 @@ These changes were done because having the note hash exposed allowed us to not h
 +        (note_hash_for_nullify, nullifier)
 +    }
 + }
-````
+```
 
 ### [Aztec.nr] `note_getter` returns `BoundedVec`
 

l1-contracts/src/core/libraries/ConstantsGen.sol

@@ -100,6 +100,7 @@ library Constants {
   uint256 internal constant GENESIS_ARCHIVE_ROOT =
     8142738430000951296386584486068033372964809139261822027365426310856631083550;
   uint256 internal constant FEE_JUICE_INITIAL_MINT = 20000000000;
+  uint256 internal constant PUBLIC_DISPATCH_SELECTOR = 3578010381;
   uint256 internal constant MAX_PACKED_PUBLIC_BYTECODE_SIZE_IN_FIELDS = 20000;
   uint256 internal constant MAX_PACKED_BYTECODE_SIZE_PER_PRIVATE_FUNCTION_IN_FIELDS = 3000;
   uint256 internal constant MAX_PACKED_BYTECODE_SIZE_PER_UNCONSTRAINED_FUNCTION_IN_FIELDS = 3000;

noir-projects/aztec-nr/aztec/src/context/private_context.nr

@@ -26,7 +26,7 @@ use dep::protocol_types::{
     MAX_PRIVATE_CALL_STACK_LENGTH_PER_CALL, MAX_PUBLIC_CALL_STACK_LENGTH_PER_CALL,
     MAX_NOTE_HASH_READ_REQUESTS_PER_CALL, MAX_NULLIFIER_READ_REQUESTS_PER_CALL,
     MAX_KEY_VALIDATION_REQUESTS_PER_CALL, MAX_ENCRYPTED_LOGS_PER_CALL, MAX_UNENCRYPTED_LOGS_PER_CALL,
-    MAX_NOTE_ENCRYPTED_LOGS_PER_CALL
+    MAX_NOTE_ENCRYPTED_LOGS_PER_CALL, PUBLIC_DISPATCH_SELECTOR
 },
     header::Header, messaging::l2_to_l1_message::L2ToL1Message, traits::Empty
 };
@@ -468,7 +468,13 @@ impl PrivateContext {
         let counter = self.next_counter();
 
         let mut is_static_call = is_static_call | self.inputs.call_context.is_static_call;
-        enqueue_public_function_call_internal(
+        // TODO(https://github.com/AztecProtocol/aztec-packages/issues/8985): Fix this.
+        // WARNING: This is insecure and should be temporary!
+        // The oracle repacks the arguments and returns a new args_hash.
+        // new_args = [selector, ...old_args], so as to make it suitable to call the public dispatch function.
+        // We don't validate or compute it in the circuit because a) it's harder to do with slices, and
+        // b) this is only temporary.
+        let args_hash = enqueue_public_function_call_internal(
             contract_address,
             function_selector,
             args_hash,
@@ -477,6 +483,10 @@ impl PrivateContext {
             is_delegate_call
         );
 
+        // Public calls are rerouted through the dispatch function.
+        let function_selector = comptime {
+            FunctionSelector::from_field(PUBLIC_DISPATCH_SELECTOR)
+        };
         let call_context = self.generate_call_context(
             contract_address,
             function_selector,
@@ -510,7 +520,13 @@ impl PrivateContext {
         let counter = self.next_counter();
 
         let mut is_static_call = is_static_call | self.inputs.call_context.is_static_call;
-        set_public_teardown_function_call_internal(
+        // TODO(https://github.com/AztecProtocol/aztec-packages/issues/8985): Fix this.
+        // WARNING: This is insecure and should be temporary!
+        // The oracle repacks the arguments and returns a new args_hash.
+        // new_args = [selector, ...old_args], so as to make it suitable to call the public dispatch function.
+        // We don't validate or compute it in the circuit because a) it's harder to do with slices, and
+        // b) this is only temporary.
+        let args_hash = set_public_teardown_function_call_internal(
             contract_address,
             function_selector,
             args_hash,
@@ -519,6 +535,9 @@ impl PrivateContext {
             is_delegate_call
         );
 
+        let function_selector = comptime {
+            FunctionSelector::from_field(PUBLIC_DISPATCH_SELECTOR)
+        };
         let call_context = self.generate_call_context(
             contract_address,
             function_selector,

noir-projects/aztec-nr/aztec/src/context/public_context.nr

@@ -1,6 +1,6 @@
 use crate::hash::{compute_secret_hash, compute_message_hash, compute_message_nullifier};
 use dep::protocol_types::address::{AztecAddress, EthAddress};
-use dep::protocol_types::constants::MAX_FIELD_VALUE;
+use dep::protocol_types::constants::{MAX_FIELD_VALUE, PUBLIC_DISPATCH_SELECTOR};
 use dep::protocol_types::traits::{Serialize, Deserialize, Empty};
 use dep::protocol_types::abis::function_selector::FunctionSelector;
 use crate::context::gas::GasOpts;
@@ -70,11 +70,12 @@ impl PublicContext {
         args: [Field],
         gas_opts: GasOpts
     ) -> FunctionReturns<RETURNS_COUNT> {
+        let args = &[function_selector.to_field()].append(args);
         let results = call(
             gas_for_call(gas_opts),
             contract_address,
             args,
-            function_selector.to_field()
+            PUBLIC_DISPATCH_SELECTOR
         );
         let data_to_return: [Field; RETURNS_COUNT] = results.0;
         let success: u8 = results.1;
@@ -90,11 +91,12 @@ impl PublicContext {
         args: [Field],
         gas_opts: GasOpts
     ) -> FunctionReturns<RETURNS_COUNT> {
+        let args = &[function_selector.to_field()].append(args);
         let (data_to_return, success): ([Field; RETURNS_COUNT], u8) = call_static(
             gas_for_call(gas_opts),
             contract_address,
             args,
-            function_selector.to_field()
+            PUBLIC_DISPATCH_SELECTOR
         );
 
         assert(success == 1, "Nested static call failed!");
@@ -127,7 +129,9 @@ impl PublicContext {
         sender()
     }
     fn selector(_self: Self) -> FunctionSelector {
-        FunctionSelector::from_u32(function_selector())
+        // The selector is the first element of the calldata when calling a public function through dispatch.
+        let raw_selector: [Field; 1] = calldata_copy(0, 1);
+        FunctionSelector::from_field(raw_selector[0])
     }
     fn get_args_hash(mut self) -> Field {
         if !self.args_hash.is_some() {
@@ -215,9 +219,10 @@ unconstrained fn sender() -> AztecAddress {
 unconstrained fn portal() -> EthAddress {
     portal_opcode()
 }
-unconstrained fn function_selector() -> u32 {
-    function_selector_opcode()
-}
+// UNUSED: Remove.
+// unconstrained fn function_selector() -> u32 {
+//     function_selector_opcode()
+// }
 unconstrained fn transaction_fee() -> Field {
     transaction_fee_opcode()
 }
@@ -321,8 +326,9 @@ unconstrained fn sender_opcode() -> AztecAddress {}
 #[oracle(avmOpcodePortal)]
 unconstrained fn portal_opcode() -> EthAddress {}
 
-#[oracle(avmOpcodeFunctionSelector)]
-unconstrained fn function_selector_opcode() -> u32 {}
+// UNUSED: Remove.
+// #[oracle(avmOpcodeFunctionSelector)]
+// unconstrained fn function_selector_opcode() -> u32 {}
 
 #[oracle(avmOpcodeTransactionFee)]
 unconstrained fn transaction_fee_opcode() -> Field {}

noir-projects/aztec-nr/aztec/src/macros/functions/mod.nr

@@ -247,7 +247,8 @@ comptime fn transform_public(f: FunctionDefinition) -> Quoted {
 
     // Unlike in the private case, in public the `context` does not need to receive the hash of the original params.
     let context_creation = quote { let mut context = dep::aztec::context::public_context::PublicContext::new(|| {
-        let serialized_args : [Field; $args_len] = dep::aztec::context::public_context::calldata_copy(0, $args_len);
+        // We start from 1 because we skip the selector for the dispatch function.
+        let serialized_args : [Field; $args_len] = dep::aztec::context::public_context::calldata_copy(1, $args_len);
         dep::aztec::hash::hash_args_array(serialized_args)
      }); };
 

noir-projects/aztec-nr/aztec/src/oracle/enqueue_public_function_call.nr

@@ -8,7 +8,7 @@ unconstrained fn enqueue_public_function_call_oracle(
     _side_effect_counter: u32,
     _is_static_call: bool,
     _is_delegate_call: bool
-) {}
+) -> Field {}
 
 unconstrained pub fn enqueue_public_function_call_internal(
     contract_address: AztecAddress,
@@ -17,15 +17,15 @@ unconstrained pub fn enqueue_public_function_call_internal(
     side_effect_counter: u32,
     is_static_call: bool,
     is_delegate_call: bool
-) {
+) -> Field {
     enqueue_public_function_call_oracle(
         contract_address,
         function_selector,
         args_hash,
         side_effect_counter,
         is_static_call,
         is_delegate_call
-    );
+    )
 }
 
 #[oracle(setPublicTeardownFunctionCall)]
@@ -36,7 +36,7 @@ unconstrained fn set_public_teardown_function_call_oracle(
     _side_effect_counter: u32,
     _is_static_call: bool,
     _is_delegate_call: bool
-) {}
+) -> Field {}
 
 unconstrained pub fn set_public_teardown_function_call_internal(
     contract_address: AztecAddress,
@@ -45,15 +45,15 @@ unconstrained pub fn set_public_teardown_function_call_internal(
     side_effect_counter: u32,
     is_static_call: bool,
     is_delegate_call: bool
-) {
+) -> Field {
     set_public_teardown_function_call_oracle(
         contract_address,
         function_selector,
         args_hash,
         side_effect_counter,
         is_static_call,
         is_delegate_call
-    );
+    )
 }
 
 pub fn notify_set_min_revertible_side_effect_counter(counter: u32) {

noir-projects/aztec-nr/aztec/src/test/helpers/test_environment.nr

@@ -12,6 +12,7 @@ use crate::hash::hash_args;
 
 use crate::note::{note_header::NoteHeader, note_interface::{NoteInterface, NullifiableNote}};
 use crate::oracle::{execution::{get_block_number, get_contract_address}, notes::notify_created_note};
+use protocol_types::constants::PUBLIC_DISPATCH_SELECTOR;
 
 pub struct TestEnvironment {}
 
@@ -142,9 +143,11 @@ impl TestEnvironment {
         let original_contract_address = get_contract_address();
         let original_fn_selector = cheatcodes::get_function_selector();
         let target_address = call_interface.get_contract_address();
-        let fn_selector = call_interface.get_selector();
         let calldata = call_interface.get_args();
 
+        // Public functions are routed through the dispatch function.
+        let fn_selector = FunctionSelector::from_field(PUBLIC_DISPATCH_SELECTOR);
+        let calldata = &[call_interface.get_selector().to_field()].append(calldata);
         cheatcodes::set_fn_selector(fn_selector);
         cheatcodes::set_contract_address(target_address);
         cheatcodes::set_msg_sender(original_contract_address);

noir-projects/aztec-nr/aztec/src/test/helpers/utils.nr

@@ -1,6 +1,6 @@
 use dep::protocol_types::{
     traits::{Deserialize, Serialize}, address::AztecAddress,
-    abis::{private_circuit_public_inputs::PrivateCircuitPublicInputs},
+    abis::{function_selector::FunctionSelector, private_circuit_public_inputs::PrivateCircuitPublicInputs},
     contract_instance::ContractInstance
 };
 
@@ -10,6 +10,7 @@ use crate::test::helpers::cheatcodes;
 use crate::keys::public_keys::{PUBLIC_KEYS_LENGTH, PublicKeys};
 
 use crate::oracle::{execution::{get_block_number, get_contract_address}};
+use protocol_types::constants::PUBLIC_DISPATCH_SELECTOR;
 
 unconstrained pub fn apply_side_effects_private(contract_address: AztecAddress, public_inputs: PrivateCircuitPublicInputs) {
     let mut nullifiers = &[];
@@ -83,7 +84,9 @@ impl<let N: u32, let M: u32> Deployer<N, M> {
         let original_fn_selector = cheatcodes::get_function_selector();
         let calldata = call_interface.get_args();
 
-        cheatcodes::set_fn_selector(call_interface.get_selector());
+        let fn_selector = FunctionSelector::from_field(PUBLIC_DISPATCH_SELECTOR);
+        let calldata = &[call_interface.get_selector().to_field()].append(calldata);
+        cheatcodes::set_fn_selector(fn_selector);
         cheatcodes::set_contract_address(instance.to_address());
         cheatcodes::set_msg_sender(original_contract_address);
         cheatcodes::set_is_static_call(call_interface.get_is_static());

noir-projects/noir-contracts/contracts/avm_test_contract/src/main.nr

@@ -480,6 +480,11 @@ contract AvmTest {
         AvmTest::at(nestedAddress).new_nullifier(nullifier + 1).call(&mut context);
     }
 
+    #[public]
+    fn nested_call_to_assert_same(arg_a: Field, arg_b: Field) -> pub Field {
+        AvmTest::at(context.this_address()).assert_same(arg_a, arg_b).call(&mut context)
+    }
+
     /**
      * Enqueue a public call from private
      */

noir-projects/noir-protocol-circuits/crates/types/src/constants.nr

@@ -137,6 +137,8 @@ global GENESIS_ARCHIVE_ROOT: Field = 0x1200a06aae1368abe36530b585bd7a4d2ba4de503
 // The following and the value in `deploy_l1_contracts` must match. We should not have the code both places, but
 // we are running into circular dependency issues. #3342
 global FEE_JUICE_INITIAL_MINT: Field = 20000000000;
+// Last 4 bytes of the Poseidon2 hash of 'public_dispatch(Field)'.
+global PUBLIC_DISPATCH_SELECTOR: Field = 0xd5441b0d;
 
 // CONTRACT CLASS CONSTANTS
 global MAX_PACKED_PUBLIC_BYTECODE_SIZE_IN_FIELDS: u32 = 20000;

yarn-project/circuits.js/src/constants.gen.ts

@@ -85,6 +85,7 @@ export const AZTEC_EPOCH_DURATION = 48;
 export const AZTEC_TARGET_COMMITTEE_SIZE = 48;
 export const GENESIS_ARCHIVE_ROOT = 8142738430000951296386584486068033372964809139261822027365426310856631083550n;
 export const FEE_JUICE_INITIAL_MINT = 20000000000;
+export const PUBLIC_DISPATCH_SELECTOR = 3578010381;
 export const MAX_PACKED_PUBLIC_BYTECODE_SIZE_IN_FIELDS = 20000;
 export const MAX_PACKED_BYTECODE_SIZE_PER_PRIVATE_FUNCTION_IN_FIELDS = 3000;
 export const MAX_PACKED_BYTECODE_SIZE_PER_UNCONSTRAINED_FUNCTION_IN_FIELDS = 3000;

yarn-project/end-to-end/src/e2e_ordering.test.ts

@@ -74,14 +74,16 @@ describe('e2e_ordering', () => {
           });
 
           // The enqueued public calls are in the expected order based on the argument they set (stack is reversed!)
-          expect(enqueuedPublicCalls.map(c => c.args[0].toBigInt())).toEqual([...expectedOrder].reverse());
+          // args[1] is used instead of args[0] because public functions are routed through the public dispatch
+          // function and args[0] is the target function selector.
+          expect(enqueuedPublicCalls.map(c => c.args[1].toBigInt())).toEqual([...expectedOrder].reverse());
 
           // Logs are emitted in the expected order
           await expectLogsFromLastBlockToBe(expectedOrder);
 
           // The final value of the child is the last one set
           const value = await pxe.getPublicStorageAt(child.address, new Fr(1));
-          expect(value.value).toBe(expectedOrder[1]); // final state should match last value set
+          expect(value.toBigInt()).toBe(expectedOrder[1]); // final state should match last value set
         },
       );
     });
@@ -106,7 +108,7 @@ describe('e2e_ordering', () => {
         await child.methods[method]().send().wait();
 
         const value = await pxe.getPublicStorageAt(child.address, new Fr(1));
-        expect(value.value).toBe(expectedOrder[expectedOrder.length - 1]); // final state should match last value set
+        expect(value.toBigInt()).toBe(expectedOrder[expectedOrder.length - 1]); // final state should match last value set
       });
 
       it.each([

yarn-project/sequencer-client/src/config.ts

@@ -189,16 +189,19 @@ function getDefaultAllowedSetupFunctions(): AllowedElement[] {
     // needed for claiming on the same tx as a spend
     {
       address: FeeJuiceAddress,
-      selector: FunctionSelector.fromSignature('_increase_public_balance((Field),Field)'),
+      // We can't restrict the selector because public functions get routed via dispatch.
+      // selector: FunctionSelector.fromSignature('_increase_public_balance((Field),Field)'),
     },
     // needed for private transfers via FPC
     {
       classId: getContractClassFromArtifact(TokenContractArtifact).id,
-      selector: FunctionSelector.fromSignature('_increase_public_balance((Field),Field)'),
+      // We can't restrict the selector because public functions get routed via dispatch.
+      // selector: FunctionSelector.fromSignature('_increase_public_balance((Field),Field)'),
     },
     {
       classId: getContractClassFromArtifact(FPCContract.artifact).id,
-      selector: FunctionSelector.fromSignature('prepare_fee((Field),Field,(Field),Field)'),
+      // We can't restrict the selector because public functions get routed via dispatch.
+      // selector: FunctionSelector.fromSignature('prepare_fee((Field),Field,(Field),Field)'),
     },
   ];
 }