chore: bump to v1.0.0-rc.1, reject trailing bytes, reject identity elemnts, more tests (#10)

Reviewed-on: #10
Co-authored-by: UneBaguette <[email protected]>
Co-committed-by: UneBaguette <[email protected]>

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 1.0.0-rc.1 (July 3, 2026)
+
+* Reject trailing bytes in all `deserialize` methods
+* Reject identity element in `deterministic_blind_unchecked` to prevent blinding bypass
+* Added roundtrip, trailing bytes, truncated, and empty input tests for serialization
+
 ## 1.0.0-rc.0 (July 2, 2026)
 
 * Added missing license in Cargo manifest

Cargo.toml

@@ -9,7 +9,7 @@ name = "voprf-vx"
 readme = "README.md"
 repository = "https://github.com/vexahub/voprf-vx/"
 rust-version = "1.87"
-version = "1.0.0-rc.0"
+version = "1.0.0-rc.1"
 
 [features]
 alloc = []
@@ -22,7 +22,7 @@ serde = ["curve25519-dalek?/serde", "hybrid-array/serde", "dep:serde"]
 std = ["alloc"]
 
 [dependencies]
-curve25519-dalek = { version = "5.0.0-rc", default-features = false, features = ["rand_core", "zeroize"], optional = true }
+curve25519-dalek = { version = "5.0.0-rc.1", default-features = false, features = ["rand_core", "zeroize"], optional = true }
 derive-where = { version = "1", features = ["zeroize-on-drop"] }
 digest = { version = "0.11", features = ["zeroize"] }
 displaydoc = { version = "0.2", default-features = false }
@@ -36,21 +36,21 @@ serde = { version = "1", default-features = false, features = [
     "derive",
 ], optional = true }
 sha2 = { version = "0.11", default-features = false, features = ["zeroize"], optional = true }
-p256 = { version = "0.14.0-rc", default-features = false, features = ["hash2curve", "oprf"], optional = true }
+p256 = { version = "0.14.0-rc.15", default-features = false, features = ["hash2curve", "oprf"], optional = true }
 subtle = { version = "2.6", default-features = false }
 zeroize = { version = "1.5", default-features = false }
 
 [dev-dependencies]
 hex = "0.4"
-p256 = { version = "0.14.0-rc", default-features = false, features = [
+p256 = { version = "0.14.0-rc.15", default-features = false, features = [
     "hash2curve",
     "oprf",
 ] }
-p384 = { version = "0.14.0-rc", default-features = false, features = [
+p384 = { version = "0.14.0-rc.15", default-features = false, features = [
     "hash2curve",
     "oprf",
 ] }
-p521 = { version = "0.14.0-rc", default-features = false, features = [
+p521 = { version = "0.14.0-rc.15", default-features = false, features = [
     "hash2curve",
     "oprf",
 ] }

README.md

@@ -16,7 +16,7 @@ Installation
 Add the following line to the dependencies of your `Cargo.toml`:
 
 ```
-voprf = { package = "voprf-vx", version = "1.0.0-rc.0" }
+voprf = { package = "voprf-vx", version = "1.0.0-rc.1" }
 ```
 
 ### Minimum Supported Rust Version

src/common.rs

@@ -397,6 +397,12 @@ pub(crate) fn deterministic_blind_unchecked<CS: CipherSuite>(
     mode: Mode,
 ) -> Result<<CS::Group as Group>::Elem> {
     let hashed_point = hash_to_group::<CS>(input, mode)?;
+
+    // Identity element would nullify blinding, revealing the input.
+    if CS::Group::is_identity_elem(hashed_point).into() {
+        return Err(Error::Input);
+    }
+
     Ok(hashed_point * blind)
 }
 

src/serialization.rs

@@ -34,6 +34,10 @@ impl<CS: CipherSuite> OprfClient<CS> {
     pub fn deserialize(mut input: &[u8]) -> Result<Self> {
         let blind = deserialize_scalar::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self { blind })
     }
 }
@@ -59,6 +63,10 @@ impl<CS: CipherSuite> VoprfClient<CS> {
         let blind = deserialize_scalar::<CS::Group>(&mut input)?;
         let blinded_element = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self {
             blind,
             blinded_element,
@@ -87,6 +95,10 @@ impl<CS: CipherSuite> PoprfClient<CS> {
         let blind = deserialize_scalar::<CS::Group>(&mut input)?;
         let blinded_element = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self {
             blind,
             blinded_element,
@@ -110,6 +122,10 @@ impl<CS: CipherSuite> OprfServer<CS> {
     pub fn deserialize(mut input: &[u8]) -> Result<Self> {
         let sk = deserialize_scalar::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self { sk })
     }
 }
@@ -134,6 +150,10 @@ impl<CS: CipherSuite> VoprfServer<CS> {
         let sk = deserialize_scalar::<CS::Group>(&mut input)?;
         let pk = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self { sk, pk })
     }
 }
@@ -158,6 +178,10 @@ impl<CS: CipherSuite> PoprfServer<CS> {
         let sk = deserialize_scalar::<CS::Group>(&mut input)?;
         let pk = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self { sk, pk })
     }
 }
@@ -183,6 +207,10 @@ impl<CS: CipherSuite> Proof<CS> {
         let c_scalar = deserialize_scalar::<CS::Group>(&mut input)?;
         let s_scalar = deserialize_scalar::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Proof { c_scalar, s_scalar })
     }
 }
@@ -203,6 +231,10 @@ impl<CS: CipherSuite> BlindedElement<CS> {
     pub fn deserialize(mut input: &[u8]) -> Result<Self> {
         let value = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self(value))
     }
 }
@@ -223,6 +255,10 @@ impl<CS: CipherSuite> EvaluationElement<CS> {
     pub fn deserialize(mut input: &[u8]) -> Result<Self> {
         let value = deserialize_elem::<CS::Group>(&mut input)?;
 
+        if !input.is_empty() {
+            return Err(Error::Deserialization);
+        }
+
         Ok(Self(value))
     }
 }
@@ -317,6 +353,7 @@ mod test {
         VoprfClient, VoprfServer,
     };
 
+    // Fuzz: no panics on arbitrary input
     macro_rules! test_deserialize {
         ($item:ident, $bytes:ident) => {
             #[cfg(feature = "ristretto255")]
@@ -324,12 +361,43 @@ mod test {
                 let _ = $item::<crate::Ristretto255>::deserialize(&$bytes[..]);
             }
 
-            let _ = $item::<p256::NistP256>::deserialize(&$bytes[..]);
-            let _ = $item::<p384::NistP384>::deserialize(&$bytes[..]);
-            let _ = $item::<p521::NistP521>::deserialize(&$bytes[..]);
+            let _ = $item::<::p256::NistP256>::deserialize(&$bytes[..]);
+            let _ = $item::<::p384::NistP384>::deserialize(&$bytes[..]);
+            let _ = $item::<::p521::NistP521>::deserialize(&$bytes[..]);
         };
     }
 
+    // Roundtrip: serialize to deserialize == original
+    macro_rules! test_roundtrip {
+        ($item:ident, $cs:ty, $constructor:expr) => {{
+            let original = $constructor;
+            let bytes = original.serialize();
+            let recovered = $item::<$cs>::deserialize(&bytes).expect("roundtrip deserialize");
+            assert_eq!(original.serialize(), recovered.serialize());
+        }};
+    }
+
+    // Trailing bytes: valid serialization + extra byte must fail
+    macro_rules! test_trailing {
+        ($item:ident, $cs:ty, $constructor:expr) => {{
+            let original = $constructor;
+            let bytes = original.serialize();
+            let mut extended = bytes.to_vec();
+            extended.push(0x00);
+            assert!($item::<$cs>::deserialize(&extended).is_err());
+        }};
+    }
+
+    // Truncated: valid serialization minus one byte must fail
+    macro_rules! test_truncated {
+        ($item:ident, $cs:ty, $constructor:expr) => {{
+            let original = $constructor;
+            let bytes = original.serialize();
+            let truncated = &bytes[..bytes.len() - 1];
+            assert!($item::<$cs>::deserialize(truncated).is_err());
+        }};
+    }
+
     proptest! {
         #[test]
         fn test_nocrash_oprf_client(bytes in vec(any::<u8>(), 0..200)) {
@@ -377,4 +445,103 @@ mod test {
             test_deserialize!(Proof, bytes);
         }
     }
+
+    macro_rules! structured_tests {
+        ($cs:ty, $mod:ident) => {
+            mod $mod {
+                use super::*;
+
+                use rand::rngs::SysRng;
+
+                #[test]
+                fn roundtrip_oprf_client() {
+                    let client = OprfClient::<$cs>::blind(b"input", &mut SysRng)
+                        .expect("blind")
+                        .state;
+                    test_roundtrip!(OprfClient, $cs, client);
+                }
+
+                #[test]
+                fn roundtrip_oprf_server() {
+                    let server = OprfServer::<$cs>::new(&mut SysRng).expect("new");
+                    test_roundtrip!(OprfServer, $cs, server);
+                }
+
+                #[test]
+                fn roundtrip_voprf_client() {
+                    let client = VoprfClient::<$cs>::blind(b"input", &mut SysRng)
+                        .expect("blind")
+                        .state;
+                    test_roundtrip!(VoprfClient, $cs, client);
+                }
+
+                #[test]
+                fn roundtrip_voprf_server() {
+                    let server = VoprfServer::<$cs>::new(&mut SysRng).expect("new");
+                    test_roundtrip!(VoprfServer, $cs, server);
+                }
+
+                #[test]
+                fn roundtrip_poprf_client() {
+                    let client = PoprfClient::<$cs>::blind(b"input", &mut SysRng)
+                        .expect("blind")
+                        .state;
+                    test_roundtrip!(PoprfClient, $cs, client);
+                }
+
+                #[test]
+                fn roundtrip_poprf_server() {
+                    let server = PoprfServer::<$cs>::new(&mut SysRng).expect("new");
+                    test_roundtrip!(PoprfServer, $cs, server);
+                }
+
+                #[test]
+                fn trailing_oprf_client() {
+                    let client = OprfClient::<$cs>::blind(b"input", &mut SysRng)
+                        .expect("blind")
+                        .state;
+                    test_trailing!(OprfClient, $cs, client);
+                }
+
+                #[test]
+                fn trailing_oprf_server() {
+                    let server = OprfServer::<$cs>::new(&mut SysRng).expect("new");
+                    test_trailing!(OprfServer, $cs, server);
+                }
+
+                #[test]
+                fn truncated_oprf_client() {
+                    let client = OprfClient::<$cs>::blind(b"input", &mut SysRng)
+                        .expect("blind")
+                        .state;
+                    test_truncated!(OprfClient, $cs, client);
+                }
+
+                #[test]
+                fn truncated_oprf_server() {
+                    let server = OprfServer::<$cs>::new(&mut SysRng).expect("new");
+                    test_truncated!(OprfServer, $cs, server);
+                }
+
+                #[test]
+                fn empty_input_fails() {
+                    assert!(OprfClient::<$cs>::deserialize(&[]).is_err());
+                    assert!(OprfServer::<$cs>::deserialize(&[]).is_err());
+                    assert!(VoprfClient::<$cs>::deserialize(&[]).is_err());
+                    assert!(VoprfServer::<$cs>::deserialize(&[]).is_err());
+                    assert!(PoprfClient::<$cs>::deserialize(&[]).is_err());
+                    assert!(PoprfServer::<$cs>::deserialize(&[]).is_err());
+                    assert!(BlindedElement::<$cs>::deserialize(&[]).is_err());
+                    assert!(EvaluationElement::<$cs>::deserialize(&[]).is_err());
+                    assert!(Proof::<$cs>::deserialize(&[]).is_err());
+                }
+            }
+        };
+    }
+
+    #[cfg(feature = "ristretto255")]
+    structured_tests!(crate::Ristretto255, ristretto255);
+    structured_tests!(::p256::NistP256, p256);
+    structured_tests!(::p384::NistP384, p384);
+    structured_tests!(::p521::NistP521, p521);
 }