impl CanonicalSerialize/Deserialize for BigUint

serialize/Cargo.toml

@@ -17,6 +17,7 @@ rust-version = "1.56"
 ark-serialize-derive = { version = "^0.3.0", path = "../serialize-derive", optional = true }
 ark-std = { version = "^0.3.0", default-features = false }
 digest = { version = "0.10", default-features = false }
+num-bigint = { version = "0.4", default-features = false }
 
 [dev-dependencies]
 sha2 = { version = "0.10", default-features = false}

serialize/src/impls.rs

@@ -7,6 +7,7 @@ use ark_std::{
     string::String,
     vec::Vec,
 };
+use num_bigint::BigUint;
 
 use crate::*;
 
@@ -147,6 +148,50 @@ impl CanonicalDeserialize for usize {
     }
 }
 
+impl CanonicalSerialize for BigUint {
+    #[inline]
+    fn serialize_with_mode<W: Write>(
+        &self,
+        writer: W,
+        compress: Compress,
+    ) -> Result<(), SerializationError> {
+        self.to_bytes_le().serialize_with_mode(writer, compress)
+    }
+
+    #[inline]
+    fn serialized_size(&self, compress: Compress) -> usize {
+        self.to_bytes_le().serialized_size(compress)
+    }
+}
+
+impl CanonicalDeserialize for BigUint {
+    #[inline]
+    fn deserialize_with_mode<R: Read>(
+        reader: R,
+        compress: Compress,
+        validate: Validate,
+    ) -> Result<Self, SerializationError> {
+        Ok(BigUint::from_bytes_le(&Vec::<u8>::deserialize_with_mode(
+            reader, compress, validate,
+        )?))
+    }
+}
+
+impl Valid for BigUint {
+    #[inline]
+    fn check(&self) -> Result<(), SerializationError> {
+        Ok(())
+    }
+
+    #[inline]
+    fn batch_check<'a>(_batch: impl Iterator<Item = &'a Self>) -> Result<(), SerializationError>
+    where
+        Self: 'a,
+    {
+        Ok(())
+    }
+}
+
 impl<T: CanonicalSerialize> CanonicalSerialize for Option<T> {
     #[inline]
     fn serialize_with_mode<W: Write>(

serialize/src/lib.rs

@@ -232,6 +232,7 @@ mod test {
         vec,
         vec::Vec,
     };
+    use num_bigint::BigUint;
 
     #[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Debug)]
     struct Dummy;
@@ -461,4 +462,25 @@ mod test {
         test_hash::<_, sha3::Sha3_256>(Dummy);
         test_hash::<_, sha3::Sha3_512>(Dummy);
     }
+
+    #[test]
+    fn test_biguint() {
+        let biguint = BigUint::from(123456u64);
+        test_serialize(biguint.clone());
+
+        let mut expected = (biguint.to_bytes_le().len() as u64).to_le_bytes().to_vec();
+        expected.extend_from_slice(&biguint.to_bytes_le());
+
+        let mut bytes = Vec::new();
+        biguint
+            .serialize_with_mode(&mut bytes, Compress::Yes)
+            .unwrap();
+        assert_eq!(bytes, expected);
+
+        let mut bytes = Vec::new();
+        biguint
+            .serialize_with_mode(&mut bytes, Compress::No)
+            .unwrap();
+        assert_eq!(bytes, expected);
+    }
 }