feat: add serde impls to Blob and Bytes48 (#342)

* feat: add serde impls to Blob and Bytes48

* remove duplicate serde file

* cargo fmt

* serialize and deserialize with prefix

* cargo fmt

* use different trusted setup based on minimal spec

* add Bytes32 serde impls

bindings/rust/Cargo.lock

@@ -93,6 +93,7 @@ dependencies = [
  "libc",
  "rand",
  "serde",
+ "serde_json",
  "serde_yaml",
 ]
 
@@ -690,9 +691,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.104"
+version = "1.0.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "076066c5f1078eac5b722a31827a8832fe108bed65dfa75e233c89f8206e976c"
+checksum = "693151e1ac27563d6dbcec9dee9fbd5da8539b20fa14ad3752b2e6d363ace360"
 dependencies = [
  "itoa",
  "ryu",

bindings/rust/Cargo.toml

@@ -31,6 +31,7 @@ criterion = "0.5.1"
 glob = "0.3.1"
 rand = "0.8.5"
 serde_yaml = "0.9.17"
+serde_json = "1.0.105"
 
 [build-dependencies]
 bindgen = { git = "https://github.com/rust-lang/rust-bindgen" , rev = "0de11f0a521611ac8738b7b01d19dddaf3899e66" }

bindings/rust/src/bindings/mod.rs

@@ -2,6 +2,7 @@
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
 
+mod serde_helpers;
 mod test_formats;
 
 include!(concat!(env!("OUT_DIR"), "/generated.rs"));
@@ -492,6 +493,12 @@ impl Deref for Bytes48 {
     }
 }
 
+impl DerefMut for Bytes48 {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.bytes
+    }
+}
+
 impl Deref for Blob {
     type Target = [u8; BYTES_PER_BLOB];
     fn deref(&self) -> &Self::Target {
@@ -693,10 +700,8 @@ mod tests {
         for test_file in test_files {
             let yaml_data = fs::read_to_string(test_file).unwrap();
             let test: compute_blob_kzg_proof::Test = serde_yaml::from_str(&yaml_data).unwrap();
-            let (Ok(blob), Ok(commitment)) = (
-                test.input.get_blob(),
-                test.input.get_commitment()
-            ) else {
+            let (Ok(blob), Ok(commitment)) = (test.input.get_blob(), test.input.get_commitment())
+            else {
                 assert!(test.get_output().is_none());
                 continue;
             };
@@ -727,7 +732,7 @@ mod tests {
                 test.input.get_commitment(),
                 test.input.get_z(),
                 test.input.get_y(),
-                test.input.get_proof()
+                test.input.get_proof(),
             ) else {
                 assert!(test.get_output().is_none());
                 continue;
@@ -758,7 +763,7 @@ mod tests {
             let (Ok(blob), Ok(commitment), Ok(proof)) = (
                 test.input.get_blob(),
                 test.input.get_commitment(),
-                test.input.get_proof()
+                test.input.get_proof(),
             ) else {
                 assert!(test.get_output().is_none());
                 continue;
@@ -789,7 +794,7 @@ mod tests {
             let (Ok(blobs), Ok(commitments), Ok(proofs)) = (
                 test.input.get_blobs(),
                 test.input.get_commitments(),
-                test.input.get_proofs()
+                test.input.get_proofs(),
             ) else {
                 assert!(test.get_output().is_none());
                 continue;

bindings/rust/src/bindings/serde_helpers.rs

@@ -0,0 +1,193 @@
+//! Serde serialization and deserialization for the basic types in this crate.
+use crate::{Blob, Bytes32, Bytes48};
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+/// Serialize a byte vec as a hex string with 0x prefix
+pub fn serialize_bytes<S, T>(x: T, s: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+    T: AsRef<[u8]>,
+{
+    s.serialize_str(&format!("0x{}", hex::encode(x.as_ref())))
+}
+
+impl Serialize for Blob {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serialize_bytes(self.bytes, serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for Blob {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let value = String::deserialize(deserializer)?;
+        let bytes_res = match value.strip_prefix("0x") {
+            Some(value) => hex::decode(value),
+            None => hex::decode(&value),
+        };
+
+        let bytes = bytes_res.map_err(|e| serde::de::Error::custom(e.to_string()))?;
+        Blob::from_bytes(bytes.as_slice()).map_err(|e| serde::de::Error::custom(format!("{:?}", e)))
+    }
+}
+
+impl Serialize for Bytes48 {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serialize_bytes(self.bytes, serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for Bytes48 {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let value = String::deserialize(deserializer)?;
+        let bytes_res = match value.strip_prefix("0x") {
+            Some(value) => hex::decode(value),
+            None => hex::decode(&value),
+        };
+
+        let bytes = bytes_res.map_err(|e| serde::de::Error::custom(e.to_string()))?;
+        Bytes48::from_bytes(bytes.as_slice())
+            .map_err(|e| serde::de::Error::custom(format!("{:?}", e)))
+    }
+}
+
+impl Serialize for Bytes32 {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serialize_bytes(self.bytes, serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for Bytes32 {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let value = String::deserialize(deserializer)?;
+        let bytes_res = match value.strip_prefix("0x") {
+            Some(value) => hex::decode(value),
+            None => hex::decode(&value),
+        };
+
+        let bytes = bytes_res.map_err(|e| serde::de::Error::custom(e.to_string()))?;
+        Bytes32::from_bytes(bytes.as_slice())
+            .map_err(|e| serde::de::Error::custom(format!("{:?}", e)))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::super::*;
+    use rand::{rngs::ThreadRng, Rng};
+    use std::path::PathBuf;
+
+    fn generate_random_blob(rng: &mut ThreadRng) -> Blob {
+        let mut arr = [0u8; BYTES_PER_BLOB];
+        rng.fill(&mut arr[..]);
+        // Ensure that the blob is canonical by ensuring that
+        // each field element contained in the blob is < BLS_MODULUS
+        for i in 0..FIELD_ELEMENTS_PER_BLOB {
+            arr[i * BYTES_PER_FIELD_ELEMENT] = 0;
+        }
+        arr.into()
+    }
+
+    fn trusted_setup_file() -> PathBuf {
+        if cfg!(feature = "minimal-spec") {
+            PathBuf::from("../../src/trusted_setup_4.txt")
+        } else {
+            PathBuf::from("../../src/trusted_setup.txt")
+        }
+    }
+
+    #[test]
+    fn test_serialize_roundtrip() {
+        // load setup so we can create commitments and blobs
+        let trusted_setup_file = trusted_setup_file();
+        assert!(trusted_setup_file.exists());
+        let kzg_settings = KZGSettings::load_trusted_setup_file(trusted_setup_file).unwrap();
+
+        // generate blob, commitment, proof
+        let mut rng = rand::thread_rng();
+        let blob = generate_random_blob(&mut rng);
+        let commitment =
+            KZGCommitment::blob_to_kzg_commitment(blob.clone(), &kzg_settings).unwrap();
+        let proof =
+            KZGProof::compute_blob_kzg_proof(blob.clone(), commitment.to_bytes(), &kzg_settings)
+                .unwrap();
+
+        // check blob serialization
+        let blob_serialized = serde_json::to_string(&blob).unwrap();
+        let blob_deserialized: Blob = serde_json::from_str(&blob_serialized).unwrap();
+        assert_eq!(blob, blob_deserialized);
+
+        // check commitment serialization
+        let commitment_serialized = serde_json::to_string(&commitment.to_bytes()).unwrap();
+        let commitment_deserialized: Bytes48 =
+            serde_json::from_str(&commitment_serialized).unwrap();
+        assert_eq!(commitment.to_bytes(), commitment_deserialized);
+
+        // check proof serialization
+        let proof_serialized = serde_json::to_string(&proof.to_bytes()).unwrap();
+        let proof_deserialized: Bytes48 = serde_json::from_str(&proof_serialized).unwrap();
+        assert_eq!(proof.to_bytes(), proof_deserialized);
+    }
+
+    #[test]
+    fn test_serialize_blob_with_prefix() {
+        // generate blob
+        let mut rng = rand::thread_rng();
+        let blob = generate_random_blob(&mut rng);
+
+        // check blob serialization
+        let blob_serialized = serde_json::to_string(&blob).unwrap();
+
+        // check that this begins with a quote and 0x
+        let mut chars = blob_serialized.chars();
+        assert_eq!(chars.next().unwrap(), '"');
+        assert_eq!(chars.next().unwrap(), '0');
+        assert_eq!(chars.next().unwrap(), 'x');
+
+        // check that it ends with a quote (sanity check)
+        assert_eq!(chars.last().unwrap(), '"');
+    }
+
+    #[test]
+    fn test_serialize_bytes_48_with_prefix() {
+        // load setup so we can create a commitments
+        let trusted_setup_file = trusted_setup_file();
+        assert!(trusted_setup_file.exists());
+        let kzg_settings = KZGSettings::load_trusted_setup_file(trusted_setup_file).unwrap();
+
+        // generate blob just to calculate a commitment
+        let mut rng = rand::thread_rng();
+        let blob = generate_random_blob(&mut rng);
+        let commitment =
+            KZGCommitment::blob_to_kzg_commitment(blob.clone(), &kzg_settings).unwrap();
+
+        // check blob serialization
+        let blob_serialized = serde_json::to_string(&commitment.to_bytes()).unwrap();
+
+        // check that this begins with a quote and 0x
+        let mut chars = blob_serialized.chars();
+        assert_eq!(chars.next().unwrap(), '"');
+        assert_eq!(chars.next().unwrap(), '0');
+        assert_eq!(chars.next().unwrap(), 'x');
+
+        // check that it ends with a quote (sanity check)
+        assert_eq!(chars.last().unwrap(), '"');
+    }
+}