refactor(public_checks): move caller helpers into aztec-nr

Author: dbanks12

noir-projects/aztec-nr/aztec/src/lib.nr

@@ -46,6 +46,7 @@ pub use protocol_types as protocol;
 pub(crate) mod logging;
 pub mod utils;
 pub mod authwit;
+pub mod public_checks;
 pub mod macros;
 
 pub mod test;

noir-projects/aztec-nr/aztec/src/public_checks.nr

@@ -0,0 +1,71 @@
+use crate::{
+    context::{calls::PublicStaticCall, PrivateContext},
+    protocol::{abis::function_selector::FunctionSelector, address::AztecAddress, constants::PUBLIC_CHECKS_ADDRESS},
+};
+
+/// Hand-written interface stub for the `PublicChecks` canonical contract.
+///
+/// The `PublicChecks` contract exposes two view functions that can be enqueued
+/// from private context via `enqueue_view_incognito` to assert timestamp or
+/// block-number constraints without revealing the calling contract address.
+///
+/// This stub exists so that the `public_checks_contract` crate itself does not
+/// need to depend on `canonical_addresses` (which would create a structural
+/// cycle). Consumer contracts call the helpers below directly via
+/// `use aztec::public_checks::*` without taking a dep on the contract crate.
+///
+/// The selectors are derived with `comptime { FunctionSelector::from_signature(...) }`,
+/// which matches exactly what the `#[aztec]` macro generates for the real contract.
+struct PublicChecksInterface {
+    target_contract: AztecAddress,
+}
+
+impl PublicChecksInterface {
+    pub fn at(target_contract: AztecAddress) -> Self {
+        Self { target_contract }
+    }
+
+    /// Returns a `PublicStaticCall` that asserts `timestamp <op> value`.
+    pub fn check_timestamp(self, operation: u8, value: u64) -> PublicStaticCall<15, 2, ()> {
+        let selector = comptime { FunctionSelector::from_signature("check_timestamp(u8,u64)") };
+        PublicStaticCall::new(
+            self.target_contract,
+            selector,
+            "check_timestamp",
+            [operation as Field, value as Field],
+        )
+    }
+
+    /// Returns a `PublicStaticCall` that asserts `block_number <op> value`.
+    pub fn check_block_number(self, operation: u8, value: u32) -> PublicStaticCall<18, 2, ()> {
+        let selector = comptime { FunctionSelector::from_signature("check_block_number(u8,u32)") };
+        PublicStaticCall::new(
+            self.target_contract,
+            selector,
+            "check_block_number",
+            [operation as Field, value as Field],
+        )
+    }
+}
+
+// docs:start:helper_public_checks_functions
+/// Asserts that the current timestamp in the enqueued public call enqueued by `check_timestamp` satisfies
+/// the `operation` with respect to the `value. Preserves privacy by performing the check via the public checks
+/// contract.
+/// This conceals an address of the calling contract by setting `context.msg_sender` to the public checks contract
+/// address.
+pub fn privately_check_timestamp(operation: u8, value: u64, context: &mut PrivateContext) {
+    PublicChecksInterface::at(PUBLIC_CHECKS_ADDRESS).check_timestamp(operation, value).enqueue_view_incognito(context);
+}
+
+/// Asserts that the current block number in the enqueued public call enqueued by `check_block_number` satisfies
+/// the `operation` with respect to the `value. Preserves privacy by performing the check via the public checks
+/// contract.
+/// This conceals an address of the calling contract by setting `context.msg_sender` to the public checks contract
+/// address.
+pub fn privately_check_block_number(operation: u8, value: u32, context: &mut PrivateContext) {
+    // docs:start:enqueueing
+    PublicChecksInterface::at(PUBLIC_CHECKS_ADDRESS).check_block_number(operation, value).enqueue_view_incognito(context);
+    // docs:end:enqueueing
+}
+// docs:end:helper_public_checks_functions

noir-projects/noir-contracts/contracts/app/app_subscription_contract/Nargo.toml

@@ -7,4 +7,3 @@ type = "contract"
 [dependencies]
 aztec = { path = "../../../../aztec-nr/aztec" }
 token = { path = "../token_contract" }
-public_checks = { path = "../../protocol/public_checks_contract" }

noir-projects/noir-contracts/contracts/app/app_subscription_contract/src/main.nr

@@ -52,7 +52,7 @@ pub contract AppSubscription {
         state_vars::{Owned, PrivateMutable, PublicImmutable},
         utils::comparison::Comparator,
     };
-    use public_checks::utils::privately_check_block_number;
+    use aztec::public_checks::privately_check_block_number;
     use token::Token;
 
     #[storage]

noir-projects/noir-contracts/contracts/app/crowdfunding_contract/Nargo.toml

@@ -8,4 +8,3 @@ type = "contract"
 aztec = { path = "../../../../aztec-nr/aztec" }
 uint_note = { path = "../../../../aztec-nr/uint-note" }
 token = { path = "../token_contract" }
-public_checks = { path = "../../protocol/public_checks_contract" }

noir-projects/noir-contracts/contracts/app/crowdfunding_contract/src/main.nr

@@ -13,7 +13,7 @@ pub contract Crowdfunding {
         utils::{array, comparison::Comparator},
     };
     use aztec::note::{constants::MAX_NOTES_PER_PAGE, HintedNote, note_getter_options::NoteStatus};
-    use public_checks::utils::privately_check_timestamp;
+    use aztec::public_checks::privately_check_timestamp;
     use token::Token;
     use uint_note::UintNote;
 

noir-projects/noir-contracts/contracts/protocol/public_checks_contract/src/main.nr

@@ -1,5 +1,4 @@
 mod test;
-pub mod utils;
 
 use aztec::macros::aztec;