Add serde for BoxedUInt

src/uint/boxed/encoding.rs

@@ -1,5 +1,8 @@
 //! Const-friendly decoding operations for [`BoxedUint`].
 
+#[cfg(feature = "serde")]
+mod serde;
+
 use super::BoxedUint;
 use crate::{uint::encoding, Limb, Word};
 use alloc::boxed::Box;

src/uint/boxed/encoding/serde.rs

@@ -0,0 +1,78 @@
+//! Support for serdect on [`BoxedUint`]
+
+use serdect::serde::{de, Deserialize, Deserializer, Serialize, Serializer};
+
+use crate::BoxedUint;
+
+impl<'de> Deserialize<'de> for BoxedUint {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let mut buffer = Self::zero().to_le_bytes();
+        serdect::array::deserialize_hex_or_bin(buffer.as_mut(), deserializer)?;
+
+        let bits_in = buffer.len() * 8;
+
+        if bits_in > u32::MAX as usize {
+            return Err(de::Error::custom(
+                "Deserialize input overflows BoxedUint u32 bits length",
+            ));
+        }
+
+        Self::from_le_slice(&buffer, bits_in as u32)
+            .map_err(|_| de::Error::custom("Deserialize error"))
+    }
+}
+
+#[cfg(feature = "serde")]
+impl Serialize for BoxedUint {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serdect::array::serialize_hex_lower_or_bin(&self.to_le_bytes(), serializer)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::BoxedUint;
+
+    #[test]
+    #[cfg(target_pointer_width = "64")]
+    fn serde() {
+        let test: BoxedUint = BoxedUint::from_be_hex("7711223344556600", 64).unwrap();
+
+        let serialized = bincode::serialize(&test).unwrap();
+        let deserialized: BoxedUint = bincode::deserialize(&serialized).unwrap();
+
+        assert_eq!(test, deserialized);
+    }
+
+    #[test]
+    #[cfg(target_pointer_width = "64")]
+    fn serde_owned() {
+        let test: BoxedUint = BoxedUint::from_be_hex("7711223344556600", 64).unwrap();
+
+        let serialized = bincode::serialize(&test).unwrap();
+        let deserialized: BoxedUint = bincode::deserialize_from(serialized.as_slice()).unwrap();
+
+        assert_eq!(test, deserialized);
+    }
+
+    #[test]
+    #[cfg(target_pointer_width = "32")]
+    fn from_le_slice_eq() {
+        let test = hex!("7766554433221100");
+        let box_uint = BoxedUint::from_le_slice(&bytes, 64).unwrap();
+
+        let serialized = bincode::serialize(&box_uint).unwrap();
+        let deserialized: BoxedUint = bincode::deserialize_from(serialized.as_slice()).unwrap();
+
+        assert_eq!(
+            deserialized.as_limbs(),
+            &[Limb(0x44556677), Limb(0x00112233)]
+        );
+    }
+}