fri_decommit developed -> audit

src/common/horner_eval.cairo

@@ -1,15 +1,17 @@
+use cairo_verifier::channel::channel::ChannelSentFelt;
+
 // `horner_eval` is a function that evaluates a polynomial at a given point using Horner's method.
 // `coefs` is an array of coefficients representing the polynomial in the format a0, a1, a2, ... an.
 // `point` is the value at which the polynomial will be evaluated.
 // The function returns the polynomial evaluation as `felt252`.
 
-fn horner_eval(coefs: Span<felt252>, point: felt252) -> felt252 {
+fn horner_eval(coefs: Span<ChannelSentFelt>, point: felt252) -> felt252 {
     let mut res = 0;
     let mut i = coefs.len();
     loop {
         if i != 0 {
             i -= 1;
-            res = *coefs.at(i) + point * res;
+            res = (*(coefs.at(i))).value + point * res;
         } else {
             break;
         }

src/common/tests/test_horner_eval.cairo

@@ -1,54 +1,55 @@
 use core::array::ArrayTrait;
+use cairo_verifier::channel::channel::ChannelSentFelt;
 use cairo_verifier::common::horner_eval::horner_eval;
 
 #[test]
 #[available_gas(9999999999)]
 fn test_horner_eval_0() {
-    let mut coefs = ArrayTrait::<felt252>::new();
+    let mut coefs = ArrayTrait::<ChannelSentFelt>::new();
     let eval = horner_eval(coefs.span(), 1);
     assert(eval == 0, 'invalid evaluation result');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_horner_eval_1() {
-    let mut coefs = ArrayTrait::<felt252>::new();
-    coefs.append(1);
+    let mut coefs = ArrayTrait::<ChannelSentFelt>::new();
+    coefs.append(ChannelSentFelt { value: 1 });
     let eval = horner_eval(coefs.span(), 7);
     assert(eval == 1, 'invalid evaluation result');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_horner_eval_2() {
-    let mut coefs = ArrayTrait::<felt252>::new();
-    coefs.append(4);
-    coefs.append(10);
-    coefs.append(19);
-    coefs.append(1);
-    coefs.append(9);
+    let mut coefs = ArrayTrait::<ChannelSentFelt>::new();
+    coefs.append(ChannelSentFelt { value: 4 });
+    coefs.append(ChannelSentFelt { value: 10 });
+    coefs.append(ChannelSentFelt { value: 19 });
+    coefs.append(ChannelSentFelt { value: 1 });
+    coefs.append(ChannelSentFelt { value: 9 });
     let eval = horner_eval(coefs.span(), 13);
     assert(eval == 262591, 'invalid evaluation result');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_horner_eval_3() {
-    let mut coefs = ArrayTrait::<felt252>::new();
-    coefs.append(4);
-    coefs.append(10);
-    coefs.append(19);
-    coefs.append(1);
-    coefs.append(9);
-    coefs.append(99);
-    coefs.append(1);
-    coefs.append(7);
-    coefs.append(13);
-    coefs.append(2);
-    coefs.append(5);
-    coefs.append(7);
-    coefs.append(111);
-    coefs.append(1);
+    let mut coefs = ArrayTrait::<ChannelSentFelt>::new();
+    coefs.append(ChannelSentFelt { value: 4 });
+    coefs.append(ChannelSentFelt { value: 10 });
+    coefs.append(ChannelSentFelt { value: 19 });
+    coefs.append(ChannelSentFelt { value: 1 });
+    coefs.append(ChannelSentFelt { value: 9 });
+    coefs.append(ChannelSentFelt { value: 99 });
+    coefs.append(ChannelSentFelt { value: 1 });
+    coefs.append(ChannelSentFelt { value: 7 });
+    coefs.append(ChannelSentFelt { value: 13 });
+    coefs.append(ChannelSentFelt { value: 2 });
+    coefs.append(ChannelSentFelt { value: 5 });
+    coefs.append(ChannelSentFelt { value: 7 });
+    coefs.append(ChannelSentFelt { value: 111 });
+    coefs.append(ChannelSentFelt { value: 1 });
     let eval = horner_eval(coefs.span(), 19);
     assert(eval == 288577899334361215, 'invalid evaluation result');
 }

src/fri/fri.cairo

@@ -16,6 +16,7 @@ use cairo_verifier::table_commitment::{TableCommitmentWitness, TableDecommitment
 use cairo_verifier::fri::fri_first_layer::gather_first_layer_queries;
 use cairo_verifier::fri::fri_group::get_fri_group;
 use cairo_verifier::fri::fri_layer::{FriLayerQuery, FriLayerComputationParams, compute_next_layer};
+use cairo_verifier::fri::fri_last_layer::verify_last_layer;
 
 // Commitment values for FRI. Used to generate a commitment by "reading" these values
 // from the channel.
@@ -194,14 +195,16 @@ fn fri_decommit(
     witness: FriWitness,
 ) {
     assert(queries.len().into() == decommitment.n_values, 'Invalid value');
-    let fri_first_layer_evaluations = decommitment.values;
 
+    // Compute first FRI layer queries.
     let fri_queries = gather_first_layer_queries(
         queries, decommitment.values, decommitment.points,
     );
 
+    // Compute fri_group.
     let fri_group = get_fri_group();
 
+    // Decommit inner layers.
     let last_queries = fri_decommit_layers(
         fri_group.span(),
         commitment.config.n_layers - 1,
@@ -211,4 +214,15 @@ fn fri_decommit(
         commitment.config.fri_step_sizes.slice(1, commitment.config.fri_step_sizes.len() - 1),
         fri_queries.span(),
     );
+
+    // Last layer.
+    assert(
+        commitment
+            .last_layer_coefficients
+            .len() == math::pow(2, commitment.config.log_last_layer_degree_bound)
+            .try_into()
+            .unwrap(),
+        'Invlid value'
+    );
+    verify_last_layer(last_queries.span(), commitment.last_layer_coefficients);
 }

src/fri/fri_last_layer.cairo

@@ -4,13 +4,14 @@ use core::traits::TryInto;
 use cairo_verifier::common::horner_eval;
 use cairo_verifier::common::math;
 use cairo_verifier::fri::fri_layer::FriLayerQuery;
+use cairo_verifier::channel::channel::ChannelSentFelt;
+
 // Verifies FRI last layer by evaluating the given polynomial on the given points (=inverses of
 // x_inv_values), and comparing the results to the given values.
-fn verify_last_layer(
-    n_queries: felt252, queries: Span<FriLayerQuery>, coefficients: Span<felt252>
-) {
+
+fn verify_last_layer(queries: Span<FriLayerQuery>, coefficients: Span<ChannelSentFelt>) {
     let mut i: u32 = 0;
-    let len: u32 = n_queries.try_into().unwrap();
+    let len: u32 = queries.len();
     loop {
         if i == len {
             break;