[chore] Expose keccak circuit config (#519)

* expose keccak circuit APIs

* expose more fields

* [chore] fix clippy

Author: zhenfeizhang

zkevm-circuits/src/keccak_circuit.rs

@@ -38,7 +38,7 @@ use crate::{
 use eth_types::Field;
 use gadgets::util::{and, not, select, sum, Expr};
 use halo2_proofs::{
-    circuit::{Layouter, Region, Value},
+    circuit::{AssignedCell, Layouter, Region, Value},
     plonk::{Column, ConstraintSystem, Error, Expression, Fixed, TableColumn, VirtualCells},
     poly::Rotation,
 };
@@ -55,7 +55,8 @@ pub struct KeccakCircuitConfig<F> {
     q_padding_last: Column<Fixed>,
     /// The columns for other circuits to lookup Keccak hash results
     pub keccak_table: KeccakTable,
-    cell_manager: CellManager<F>,
+    /// Expose the columns that stores the cells for hash input/output
+    pub cell_manager: CellManager<F>,
     round_cst: Column<Fixed>,
     normalize_3: [TableColumn; 2],
     normalize_4: [TableColumn; 2],
@@ -890,12 +891,13 @@ impl<F: Field> KeccakCircuitConfig<F> {
         )
     }
 
-    fn set_row(
+    /// Set the cells for a keccak row; return the cells that are assigned.
+    pub fn set_row(
         &self,
         region: &mut Region<'_, F>,
         offset: usize,
         row: &KeccakRow<F>,
-    ) -> Result<(), Error> {
+    ) -> Result<Vec<AssignedCell<F, F>>, Error> {
         // Fixed selectors
         for (name, column, value) in &[
             ("q_enable", self.q_enable, F::from(row.q_enable)),
@@ -930,18 +932,19 @@ impl<F: Field> KeccakCircuitConfig<F> {
         )?;
 
         // Cell values
+        let mut res = vec![];
         for (idx, (bit, column)) in row
             .cell_values
             .iter()
             .zip(self.cell_manager.columns())
             .enumerate()
         {
-            region.assign_advice(
+            res.push(region.assign_advice(
                 || format!("assign lookup value {} {}", idx, offset),
                 column.advice,
                 offset,
                 || Value::known(*bit),
-            )?;
+            )?);
         }
 
         // Round constant
@@ -952,10 +955,11 @@ impl<F: Field> KeccakCircuitConfig<F> {
             || Value::known(row.round_cst),
         )?;
 
-        Ok(())
+        Ok(res)
     }
 
-    pub(crate) fn load_aux_tables(&self, layouter: &mut impl Layouter<F>) -> Result<(), Error> {
+    /// Load the auxiliary table for keccak table.
+    pub fn load_aux_tables(&self, layouter: &mut impl Layouter<F>) -> Result<(), Error> {
         load_normalize_table(layouter, "normalize_6", &self.normalize_6, 6u64)?;
         load_normalize_table(layouter, "normalize_4", &self.normalize_4, 4u64)?;
         load_normalize_table(layouter, "normalize_3", &self.normalize_3, 3u64)?;
@@ -969,7 +973,8 @@ impl<F: Field> KeccakCircuitConfig<F> {
         load_pack_table(layouter, &self.pack_table)
     }
 
-    fn annotate_circuit(&self, region: &mut Region<F>) {
+    /// Annotate the circuit
+    pub fn annotate_circuit(&self, region: &mut Region<F>) {
         //region.name_column(|| "KECCAK_q_enable", self.q_enable);
         region.name_column(|| "KECCAK_q_first", self.q_first);
         region.name_column(|| "KECCAK_q_round", self.q_round);

zkevm-circuits/src/keccak_circuit/cell_manager.rs

@@ -89,14 +89,14 @@ impl<F: FieldExt> Expr<F> for &Cell<F> {
 
 /// CellColumn
 #[derive(Clone, Debug)]
-pub(crate) struct CellColumn<F> {
-    pub(crate) advice: Column<Advice>,
+pub struct CellColumn<F> {
+    pub advice: Column<Advice>,
     pub(crate) expr: Expression<F>,
 }
 
 /// CellManager
 #[derive(Clone, Debug)]
-pub(crate) struct CellManager<F> {
+pub struct CellManager<F> {
     height: usize,
     columns: Vec<CellColumn<F>>,
     rows: Vec<usize>,
@@ -153,7 +153,8 @@ impl<F: FieldExt> CellManager<F> {
         self.rows.iter().cloned().max().unwrap()
     }
 
-    pub(crate) fn columns(&self) -> &[CellColumn<F>] {
+    /// expose the columns used for keccak cell
+    pub fn columns(&self) -> &[CellColumn<F>] {
         &self.columns
     }
 

zkevm-circuits/src/keccak_circuit/keccak_packed_multi.rs

@@ -67,9 +67,12 @@ pub struct KeccakRow<F: Field> {
     pub(crate) q_padding: bool,
     pub(crate) q_padding_last: bool,
     pub(crate) round_cst: F,
-    pub(crate) is_final: bool,
-    pub(crate) cell_values: Vec<F>,
-    pub(crate) length: usize,
+    /// if the row is the last row of the current keccak hash
+    pub is_final: bool,
+    /// the value of the cells that are to be assigned
+    pub cell_values: Vec<F>,
+    /// the length of the hash input
+    pub length: usize,
     pub(crate) data_rlc: Value<F>,
     pub(crate) hash_rlc: Value<F>,
 }