From 67509daca7064fe3e10e44887a7227a70ef744a5 Mon Sep 17 00:00:00 2001
From: Jacob Kaufmann <jacobkaufmann18@gmail.com>
Date: Wed, 13 Mar 2024 12:20:30 -0600
Subject: [PATCH] refactor: add byte array type for deserialization (#46)

---
 Cargo.toml       |  2 +-
 src/bytes.rs     | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/kzg/setup.rs | 33 +++++++++---------------------
 src/kzg/spec.rs  | 12 ++++++-----
 src/lib.rs       |  1 +
 5 files changed, 70 insertions(+), 30 deletions(-)
 create mode 100644 src/bytes.rs

diff --git a/Cargo.toml b/Cargo.toml
index 14ce3bf..e7106a3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,9 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-alloy-primitives = { version = "0.4.2", features = ["std", "serde"] }
 blst = "0.3.11"
 criterion = "0.5.1"
+hex = "0.4.3"
 rand = { version = "0.8.5", optional = true }
 serde = { version = "1.0.189", features = ["derive"] }
 serde_json = "1.0.107"
diff --git a/src/bytes.rs b/src/bytes.rs
new file mode 100644
index 0000000..24ca55d
--- /dev/null
+++ b/src/bytes.rs
@@ -0,0 +1,52 @@
+use serde::{de::Visitor, Deserialize};
+
+#[derive(Clone, Debug)]
+pub struct Bytes(Vec<u8>);
+
+impl AsRef<[u8]> for Bytes {
+    fn as_ref(&self) -> &[u8] {
+        self.0.as_ref()
+    }
+}
+
+pub struct BytesVisitor;
+
+impl<'de> Visitor<'de> for BytesVisitor {
+    type Value = Vec<u8>;
+
+    fn expecting(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+        formatter.write_str(
+            "a variable-length byte array represented by a raw byte array or a hex-encoded string",
+        )
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        let v = v.strip_prefix("0x").unwrap_or(v);
+        let v = hex::decode(v).map_err(E::custom)?;
+        Ok(v)
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        let v = hex::decode(v).map_err(E::custom)?;
+        Ok(v)
+    }
+}
+
+impl<'de> Deserialize<'de> for Bytes {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        if deserializer.is_human_readable() {
+            deserializer.deserialize_str(BytesVisitor).map(Bytes)
+        } else {
+            deserializer.deserialize_bytes(BytesVisitor).map(Bytes)
+        }
+    }
+}
diff --git a/src/kzg/setup.rs b/src/kzg/setup.rs
index 2e97e99..2124ff3 100644
--- a/src/kzg/setup.rs
+++ b/src/kzg/setup.rs
@@ -7,23 +7,23 @@ use std::{
 use super::{Bytes32, Bytes48, Commitment, Error, Polynomial, Proof};
 use crate::{
     blob::{Blob, Error as BlobError},
-    bls::{self, Decompress, ECGroupError, Error as BlsError, Fr, P1, P2},
+    bls::{self, Decompress, Error as BlsError, Fr, P1, P2},
+    bytes::Bytes,
     math,
 };
 
-use alloy_primitives::{hex, Bytes, FixedBytes};
+use serde::Deserialize;
 
 #[derive(Debug)]
 pub enum LoadSetupError {
     Bls(BlsError),
     Io(io::Error),
-    Hex(hex::FromHexError),
     Serde(serde_json::Error),
     InvalidLenG1Lagrange,
     InvalidLenG2Monomial,
 }
 
-#[derive(serde::Deserialize, serde::Serialize)]
+#[derive(Deserialize)]
 struct SetupUnchecked {
     g1_lagrange: Vec<Bytes>,
     g2_monomial: Vec<Bytes>,
@@ -52,13 +52,6 @@ impl<const G1: usize, const G2: usize> Setup<G1, G2> {
 
         let mut g1_lagrange: Box<[P1; G1]> = Box::new([P1::default(); G1]);
         for (i, point) in setup.g1_lagrange.iter().enumerate() {
-            if point.len() != 48 {
-                return Err(LoadSetupError::Bls(BlsError::from(
-                    ECGroupError::InvalidEncoding,
-                )));
-            }
-            // TODO: skip unnecessary allocation
-            let point = FixedBytes::<48>::from_slice(point);
             let point =
                 P1::decompress(point).map_err(|err| LoadSetupError::Bls(BlsError::from(err)))?;
             g1_lagrange[i] = point;
@@ -67,13 +60,6 @@ impl<const G1: usize, const G2: usize> Setup<G1, G2> {
 
         let mut g2_monomial: Box<[P2; G2]> = Box::new([P2::default(); G2]);
         for (i, point) in setup.g2_monomial.iter().enumerate() {
-            if point.len() != 96 {
-                return Err(LoadSetupError::Bls(BlsError::from(
-                    ECGroupError::InvalidEncoding,
-                )));
-            }
-            // TODO: skip unnecessary allocation
-            let point = FixedBytes::<96>::from_slice(point);
             let point =
                 P2::decompress(point).map_err(|err| LoadSetupError::Bls(BlsError::from(err)))?;
             g2_monomial[i] = point;
@@ -287,12 +273,11 @@ impl<const G1: usize, const G2: usize> Setup<G1, G2> {
 mod tests {
     use super::*;
 
-    use crate::{
-        bls::Compress,
-        kzg::spec::{
-            BlobToCommitment, ComputeBlobProof, ComputeProof, VerifyBlobProof,
-            VerifyBlobProofBatch, VerifyProof,
-        },
+    use crate::bls::Compress;
+
+    use crate::kzg::spec::{
+        BlobToCommitment, ComputeBlobProof, ComputeProof, VerifyBlobProof, VerifyBlobProofBatch,
+        VerifyProof,
     };
 
     use std::{
diff --git a/src/kzg/spec.rs b/src/kzg/spec.rs
index c6473f5..54557b7 100644
--- a/src/kzg/spec.rs
+++ b/src/kzg/spec.rs
@@ -1,18 +1,20 @@
-use alloy_primitives::{Bytes, FixedBytes};
 use serde::Deserialize;
 
-use crate::bls::{Fr, P1};
+use crate::{
+    bls::{Fr, P1},
+    bytes::Bytes,
+};
 
 use super::{Bytes32, Bytes48};
 
 fn bytes32_from_bytes(bytes: &Bytes) -> Option<Bytes32> {
-    let bytes = FixedBytes::<{ Fr::BYTES }>::try_from(bytes.as_ref()).ok();
+    let bytes: Option<[u8; Fr::BYTES]> = TryFrom::try_from(bytes.as_ref()).ok();
     bytes.map(Into::<Bytes32>::into)
 }
 
 fn bytes48_from_bytes(bytes: &Bytes) -> Option<Bytes48> {
-    let bytes = FixedBytes::<{ P1::BYTES }>::try_from(bytes.as_ref()).ok()?;
-    Some(bytes.into())
+    let bytes: Option<[u8; P1::BYTES]> = TryFrom::try_from(bytes.as_ref()).ok();
+    bytes.map(Into::<Bytes48>::into)
 }
 
 #[derive(Deserialize)]
diff --git a/src/lib.rs b/src/lib.rs
index 611fc29..4d9b1c0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 mod bls;
+mod bytes;
 mod math;
 
 pub use bls::{Compress, Decompress};