From 65ed1d8568225b3bd13434bb2a9c947123f771f0 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Tue, 22 Dec 2020 08:38:22 -0700
Subject: [PATCH] Check h_evals/h_commitments lengths in vanishing argument
 verifier.

---
 src/plonk/vanishing/verifier.rs | 10 +++++++---
 src/plonk/verifier.rs           |  2 ++
 src/poly/domain.rs              |  5 +++++
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/plonk/vanishing/verifier.rs b/src/plonk/vanishing/verifier.rs
index e86cb62..f50ddd9 100644
--- a/src/plonk/vanishing/verifier.rs
+++ b/src/plonk/vanishing/verifier.rs
@@ -9,10 +9,14 @@ use crate::{
 };
 
 impl<C: CurveAffine> Proof<C> {
-    pub(in crate::plonk) fn check_lengths(&self, _vk: &VerifyingKey<C>) -> Result<(), Error> {
-        // TODO: check h_evals
+    pub(in crate::plonk) fn check_lengths(&self, vk: &VerifyingKey<C>) -> Result<(), Error> {
+        if self.h_commitments.len() != self.h_evals.len() {
+            return Err(Error::IncompatibleParams);
+        }
 
-        // TODO: check h_commitments
+        if self.h_commitments.len() != vk.domain.get_quotient_poly_degree() {
+            return Err(Error::IncompatibleParams);
+        }
 
         Ok(())
     }
diff --git a/src/plonk/verifier.rs b/src/plonk/verifier.rs
index bc21231..11de2b8 100644
--- a/src/plonk/verifier.rs
+++ b/src/plonk/verifier.rs
@@ -182,6 +182,8 @@ impl<'a, C: CurveAffine> Proof<C> {
             .map(|p| p.check_lengths(vk))
             .transpose()?;
 
+        self.vanishing.check_lengths(vk)?;
+
         if self.lookups.len() != vk.cs.lookups.len() {
             return Err(Error::IncompatibleParams);
         }
diff --git a/src/poly/domain.rs b/src/poly/domain.rs
index 022a67c..c6358ac 100644
--- a/src/poly/domain.rs
+++ b/src/poly/domain.rs
@@ -382,4 +382,9 @@ impl<G: Group> EvaluationDomain<G> {
     pub fn get_barycentric_weight(&self) -> G::Scalar {
         self.barycentric_weight
     }
+
+    /// Gets the quotient polynomial's degree (as a multiple of n)
+    pub fn get_quotient_poly_degree(&self) -> usize {
+        self.quotient_poly_degree as usize
+    }
 }