Use digest(as = ...) attribute

Signed-off-by: Denis Varlakov <[email protected]>

cggmp21-keygen/src/non_threshold.rs

@@ -68,7 +68,7 @@ pub struct MsgRound2<E: Curve, L: SecurityLevel> {
     /// Party contribution to chain code
     #[cfg(feature = "hd-wallets")]
     #[serde_as(as = "Option<utils::HexOrBin>")]
-    #[udigest(with = utils::encoding::maybe_bytes)]
+    #[udigest(as = Option<udigest::Bytes>)]
     pub chain_code: Option<slip_10::ChainCode>,
     /// $u_i$
     #[serde(with = "hex::serde")]

cggmp21-keygen/src/threshold.rs

@@ -71,7 +71,7 @@ pub struct MsgRound2Broad<E: Curve, L: SecurityLevel> {
     /// Party contribution to chain code
     #[cfg(feature = "hd-wallets")]
     #[serde_as(as = "Option<utils::HexOrBin>")]
-    #[udigest(with = utils::encoding::maybe_bytes)]
+    #[udigest(as = Option<udigest::Bytes>)]
     pub chain_code: Option<slip_10::ChainCode>,
     /// $u_i$
     #[serde(with = "hex::serde")]

cggmp21-keygen/src/utils.rs

@@ -90,15 +90,3 @@ where
 pub fn iter_peers(i: u16, n: u16) -> impl Iterator<Item = u16> {
     (0..n).filter(move |x| *x != i)
 }
-
-/// Unambiguous encoding for different types for which it was not defined
-pub mod encoding {
-    #[cfg(feature = "hd-wallets")]
-    pub fn maybe_bytes<B: udigest::Buffer>(
-        m: &Option<impl AsRef<[u8]>>,
-        encoder: udigest::encoding::EncodeValue<B>,
-    ) {
-        use udigest::Digestable;
-        m.as_ref().map(udigest::Bytes).unambiguously_encode(encoder)
-    }
-}

cggmp21/src/key_refresh/aux_only.rs

@@ -65,13 +65,13 @@ pub struct MsgRound1<D: Digest> {
 #[serde(bound = "")]
 pub struct MsgRound2<L: SecurityLevel> {
     /// $N_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub N: Integer,
     /// $s_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub s: Integer,
     /// $t_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub t: Integer,
     /// $\hat \psi_i$
     // this should be L::M instead, but no rustc support yet

cggmp21/src/key_refresh/non_threshold.rs

@@ -77,13 +77,13 @@ pub struct MsgRound2<E: Curve, L: SecurityLevel> {
     /// $\vec A_i$
     pub sch_commits_a: Vec<schnorr_pok::Commit<E>>,
     /// $N_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub N: Integer,
     /// $s_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub s: Integer,
     /// $t_i$
-    #[udigest(with = utils::encoding::integer)]
+    #[udigest(as = utils::encoding::Integer)]
     pub t: Integer,
     /// $\hat \psi_i$
     // this should be L::M instead, but no rustc support yet

cggmp21/src/signing.rs

@@ -153,10 +153,10 @@ pub mod msg {
     #[udigest(tag = prefixed!("round1"))]
     pub struct MsgRound1a {
         /// $K_i$
-        #[udigest(with = utils::encoding::integer)]
+        #[udigest(as = utils::encoding::Integer)]
         pub K: fast_paillier::Ciphertext,
         /// $G_i$
-        #[udigest(with = utils::encoding::integer)]
+        #[udigest(as = utils::encoding::Integer)]
         pub G: fast_paillier::Ciphertext,
     }
 

cggmp21/src/utils.rs

@@ -219,22 +219,13 @@ pub fn generate_blum_prime(rng: &mut impl rand_core::RngCore, bits_size: u32) ->
 pub mod encoding {
     use paillier_zk::rug;
 
-    pub fn integer<B: udigest::Buffer>(
-        x: &rug::Integer,
-        encoder: udigest::encoding::EncodeValue<B>,
-    ) {
-        encoder
-            .encode_leaf()
-            .chain(x.to_digits(rug::integer::Order::Msf));
-    }
-
-    pub fn integers_list<B: udigest::Buffer>(
-        list: impl AsRef<[rug::Integer]>,
-        encoder: udigest::encoding::EncodeValue<B>,
-    ) {
-        let mut encoder = encoder.encode_list();
-        for x in list.as_ref() {
-            integer(x, encoder.add_item())
+    pub struct Integer;
+    impl udigest::DigestAs<rug::Integer> for Integer {
+        fn digest_as<B: udigest::Buffer>(
+            x: &rug::Integer,
+            encoder: udigest::encoding::EncodeValue<B>,
+        ) {
+            encoder.encode_leaf_value(x.to_digits(rug::integer::Order::Msf))
         }
     }
 }

cggmp21/src/zk/ring_pedersen_parameters.rs

@@ -17,11 +17,11 @@ struct Challenge<const M: usize> {
 /// Data to construct proof about
 #[derive(Clone, Copy, udigest::Digestable)]
 pub struct Data<'a> {
-    #[udigest(with = crate::utils::encoding::integer)]
+    #[udigest(as = &crate::utils::encoding::Integer)]
     pub N: &'a Integer,
-    #[udigest(with = crate::utils::encoding::integer)]
+    #[udigest(as = &crate::utils::encoding::Integer)]
     pub s: &'a Integer,
-    #[udigest(with = crate::utils::encoding::integer)]
+    #[udigest(as = &crate::utils::encoding::Integer)]
     pub t: &'a Integer,
 }
 
@@ -34,10 +34,10 @@ pub struct Data<'a> {
 #[derive(Clone, Serialize, Deserialize, udigest::Digestable)]
 pub struct Proof<const M: usize> {
     #[serde_as(as = "[_; M]")]
-    #[udigest(with = crate::utils::encoding::integers_list)]
+    #[udigest(as = [crate::utils::encoding::Integer; M])]
     pub commitment: [Integer; M],
     #[serde_as(as = "[_; M]")]
-    #[udigest(with = crate::utils::encoding::integers_list)]
+    #[udigest(as = [crate::utils::encoding::Integer; M])]
     pub zs: [Integer; M],
 }
 
@@ -51,7 +51,7 @@ fn derive_challenge<const M: usize, D: Digest>(
     struct Seed<'a, S: udigest::Digestable, const M: usize> {
         shared_state: &'a S,
         data: Data<'a>,
-        #[udigest(with = crate::utils::encoding::integers_list)]
+        #[udigest(as = &[crate::utils::encoding::Integer; M])]
         commitment: &'a [Integer; M],
     }
 

key-share/src/lib.rs

@@ -204,7 +204,7 @@ pub struct DirtyKeyInfo<E: Curve> {
     // `crate::serde_fix` as well!
     //
     /// Guard that ensures curve consistency for deseraization
-    #[cfg_attr(feature = "udigest", udigest(with = utils::encoding::curve_name))]
+    #[cfg_attr(feature = "udigest", udigest(as = utils::encoding::CurveName))]
     pub curve: CurveName<E>,
     /// Public key corresponding to shared secret key. Corresponds to _X_ in paper.
     #[cfg_attr(feature = "serde", serde(with = "As::<generic_ec::serde::Compact>"))]
@@ -231,7 +231,7 @@ pub struct DirtyKeyInfo<E: Curve> {
         serde(skip_serializing_if = "Option::is_none"),
         serde(with = "As::<Option<utils::HexOrBin>>")
     )]
-    #[cfg_attr(feature = "udigest", udigest(with = utils::encoding::maybe_bytes))]
+    #[cfg_attr(feature = "udigest", udigest(as = Option<udigest::Bytes>))]
     pub chain_code: Option<slip_10::ChainCode>,
 }
 

key-share/src/utils.rs

@@ -12,20 +12,14 @@ use hex as _;
 
 #[cfg(feature = "udigest")]
 pub mod encoding {
-    pub fn curve_name<B: udigest::Buffer, E: generic_ec::Curve>(
-        _value: &generic_ec::serde::CurveName<E>,
-        encoder: udigest::encoding::EncodeValue<B>,
-    ) {
-        encoder.encode_leaf_value(E::CURVE_NAME)
-    }
-
-    #[cfg(feature = "hd-wallets")]
-    pub fn maybe_bytes<B: udigest::Buffer>(
-        m: &Option<impl AsRef<[u8]>>,
-        encoder: udigest::encoding::EncodeValue<B>,
-    ) {
-        use udigest::Digestable;
-        m.as_ref().map(udigest::Bytes).unambiguously_encode(encoder)
+    pub struct CurveName;
+    impl<E: generic_ec::Curve> udigest::DigestAs<generic_ec::serde::CurveName<E>> for CurveName {
+        fn digest_as<B: udigest::Buffer>(
+            _value: &generic_ec::serde::CurveName<E>,
+            encoder: udigest::encoding::EncodeValue<B>,
+        ) {
+            encoder.encode_leaf_value(E::CURVE_NAME)
+        }
     }
 }