fix: min expiration timestamp instead of assert

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/components/tail_output_composer.nr

@@ -12,6 +12,7 @@ use types::{
             PrivateKernelCircuitPublicInputs, PrivateToRollupKernelCircuitPublicInputs,
         },
     },
+    constants::MAX_TX_LIFETIME,
     traits::Empty,
 };
 
@@ -38,9 +39,14 @@ impl TailOutputComposer {
 
         let gas_used = meter_gas_used(self.previous_kernel, false /* is_for_public */);
 
+        let max_timestamp =
+            source.constants.anchor_block_header.global_variables.timestamp + MAX_TX_LIFETIME;
         let expiration_timestamp = std::cmp::min(
-            source.expiration_timestamp,
-            self.expiration_timestamp_upper_bound,
+            std::cmp::min(
+                source.expiration_timestamp,
+                self.expiration_timestamp_upper_bound,
+            ),
+            max_timestamp,
         );
 
         PrivateToRollupKernelCircuitPublicInputs {

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/components/tail_output_validator.nr

@@ -1,14 +1,13 @@
-mod validate_expiration_timestamp;
-
-pub(crate) use validate_expiration_timestamp::validate_expiration_timestamp;
-
 use crate::{
     accumulated_data::{assert_sorted_transformed_array, assert_transformed_array},
     components::gas_meter::meter_gas_used,
 };
 
-use types::abis::kernel_circuit_public_inputs::{
-    PrivateKernelCircuitPublicInputs, PrivateToRollupKernelCircuitPublicInputs,
+use types::{
+    abis::kernel_circuit_public_inputs::{
+        PrivateKernelCircuitPublicInputs, PrivateToRollupKernelCircuitPublicInputs,
+    },
+    constants::MAX_TX_LIFETIME,
 };
 
 pub struct TailOutputValidator {
@@ -62,14 +61,21 @@ impl TailOutputValidator {
         // This value can only decrease with each iteration. Here we take the minimum of:
         // - The value from the previous kernel iteration
         // - An upper bound value set by the user
+        let max_timestamp = self
+            .previous_kernel
+            .constants
+            .anchor_block_header
+            .global_variables
+            .timestamp
+            + MAX_TX_LIFETIME;
         let expiration_timestamp = std::cmp::min(
-            self.previous_kernel.expiration_timestamp,
-            self.expiration_timestamp_upper_bound,
-        );
-        validate_expiration_timestamp(
-            expiration_timestamp,
-            self.previous_kernel.constants.anchor_block_header.global_variables,
+            std::cmp::min(
+                self.previous_kernel.expiration_timestamp,
+                self.expiration_timestamp_upper_bound,
+            ),
+            max_timestamp,
         );
+
         assert_eq(
             self.output.expiration_timestamp,
             expiration_timestamp,

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/components/tail_to_public_output_composer.nr

@@ -9,8 +9,11 @@ use crate::{
         private_kernel_circuit_output_composer::PrivateKernelCircuitOutputComposer,
     },
 };
-use types::abis::kernel_circuit_public_inputs::{
-    PrivateKernelCircuitPublicInputs, PrivateToPublicKernelCircuitPublicInputs,
+use types::{
+    abis::kernel_circuit_public_inputs::{
+        PrivateKernelCircuitPublicInputs, PrivateToPublicKernelCircuitPublicInputs,
+    },
+    constants::MAX_TX_LIFETIME,
 };
 
 pub struct TailToPublicOutputComposer {
@@ -46,9 +49,14 @@ impl TailToPublicOutputComposer {
 
         let gas_used = meter_gas_used(self.previous_kernel, true /* is_for_public */);
 
+        let max_timestamp =
+            source.constants.anchor_block_header.global_variables.timestamp + MAX_TX_LIFETIME;
         let expiration_timestamp = std::cmp::min(
-            source.expiration_timestamp,
-            self.expiration_timestamp_upper_bound,
+            std::cmp::min(
+                source.expiration_timestamp,
+                self.expiration_timestamp_upper_bound,
+            ),
+            max_timestamp,
         );
 
         let mut output = PrivateToPublicKernelCircuitPublicInputs {

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/components/tail_to_public_output_validator.nr

@@ -4,10 +4,13 @@ use crate::{
         assert_split_sorted_transformed_arrays,
         assert_split_transformed_arrays_from_sorted_padded_array,
     },
-    components::{gas_meter::meter_gas_used, tail_output_validator::validate_expiration_timestamp},
+    components::gas_meter::meter_gas_used,
 };
-use types::abis::kernel_circuit_public_inputs::{
-    PrivateKernelCircuitPublicInputs, PrivateToPublicKernelCircuitPublicInputs,
+use types::{
+    abis::kernel_circuit_public_inputs::{
+        PrivateKernelCircuitPublicInputs, PrivateToPublicKernelCircuitPublicInputs,
+    },
+    constants::MAX_TX_LIFETIME,
 };
 
 pub struct TailToPublicOutputValidator {
@@ -52,14 +55,21 @@ impl TailToPublicOutputValidator {
         // This value can only decrease with each iteration. Here we take the minimum of:
         // - The value from the previous kernel iteration
         // - An upper bound value set by the user
+        let max_timestamp = self
+            .previous_kernel
+            .constants
+            .anchor_block_header
+            .global_variables
+            .timestamp
+            + MAX_TX_LIFETIME;
         let expiration_timestamp = std::cmp::min(
-            self.previous_kernel.expiration_timestamp,
-            self.expiration_timestamp_upper_bound,
-        );
-        validate_expiration_timestamp(
-            expiration_timestamp,
-            self.previous_kernel.constants.anchor_block_header.global_variables,
+            std::cmp::min(
+                self.previous_kernel.expiration_timestamp,
+                self.expiration_timestamp_upper_bound,
+            ),
+            max_timestamp,
         );
+
         assert_eq(
             self.output.expiration_timestamp,
             expiration_timestamp,

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/tests/private_kernel_tail/tail_output_validator/validate_propagated_values_tests.nr

@@ -127,7 +127,7 @@ fn expiration_timestamp_custom_equals_max_duration() {
     builder.validate();
 }
 
-#[test(should_fail_with = "expiration_timestamp exceeds max tx lifetime")]
+#[test]
 fn expiration_timestamp_custom_exceeds_max_tx_lifetime() {
     let mut builder = TestBuilder::new();
 
@@ -138,8 +138,8 @@ fn expiration_timestamp_custom_exceeds_max_tx_lifetime() {
     let max_timestamp = block_timestamp + MAX_TX_LIFETIME;
     builder.expiration_timestamp_upper_bound = max_timestamp + 1;
     builder.previous_kernel.expiration_timestamp = max_timestamp + 1;
-    // Output should be the max timestamp.
-    builder.output.expiration_timestamp = max_timestamp + 1;
+    // Output should be clamped to the max timestamp.
+    builder.output.expiration_timestamp = max_timestamp;
 
     builder.validate();
 }

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/tests/private_kernel_tail_to_public/tail_to_public_output_validator/validate_propagated_values_tests.nr

@@ -127,7 +127,7 @@ fn expiration_timestamp_custom_equals_max_tx_lifetime() {
     builder.validate();
 }
 
-#[test(should_fail_with = "expiration_timestamp exceeds max tx lifetime")]
+#[test]
 fn expiration_timestamp_custom_exceeds_max_tx_lifetime() {
     let mut builder = TestBuilder::new();
 
@@ -138,8 +138,8 @@ fn expiration_timestamp_custom_exceeds_max_tx_lifetime() {
     let max_timestamp = block_timestamp + MAX_TX_LIFETIME;
     builder.expiration_timestamp_upper_bound = max_timestamp + 1;
     builder.previous_kernel.expiration_timestamp = max_timestamp + 1;
-    // Output should be the max timestamp.
-    builder.output.expiration_timestamp = max_timestamp + 1;
+    // Output should be clamped to the max timestamp.
+    builder.output.expiration_timestamp = max_timestamp;
 
     builder.validate();
 }