Use #[udigest(as = ...)] attribute

CHANGELOG.md

@@ -1,3 +1,8 @@
+## v0.4.1
+* Prettify code by using `#[udigest(as = ...)]` attribute [#51]
+
+[#51]: https://github.com/dfns/paillier-zk/pull/51
+
 ## v0.4.0
 * security fix: derive challenges for zero-knowledge proof unambiguously
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "paillier-zk"
-version = "0.4.0"
+version = "0.4.1"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "ZK-proofs for Paillier encryption scheme"
@@ -22,7 +22,7 @@ thiserror = "1"
 serde = { version = "1", features = ["derive"], optional = true }
 serde_with = { version = "3", default-features = false, features = ["macros"], optional = true }
 
-udigest = { version = "0.2", default-features = false, features = ["inline-struct", "derive"] }
+udigest = { version = "0.2.1", default-features = false, features = ["inline-struct", "derive"] }
 rand_hash = "0.1"
 
 [dev-dependencies]
@@ -49,4 +49,3 @@ required-features = ["serde"]
 
 [package.metadata.docs.rs]
 all-features = true
-

src/common.rs

@@ -267,25 +267,29 @@ pub fn fail_if_ne<T: PartialEq, E>(err: E, lhs: T, rhs: T) -> Result<(), E> {
     }
 }
 
-/// Digests an integer
-///
-/// To be used within `#[udigest(with = "...")]` attribute
-pub fn digest_integer<B: udigest::Buffer>(
-    value: &Integer,
-    encoder: udigest::encoding::EncodeValue<B>,
-) {
-    let digits = value.to_digits::<u8>(rug::integer::Order::Msf);
-    encoder.encode_leaf_value(digits)
-}
+pub mod encoding {
+    /// Digests a rug integer
+    pub struct Integer;
+    impl udigest::DigestAs<rug::Integer> for Integer {
+        fn digest_as<B: udigest::Buffer>(
+            value: &rug::Integer,
+            encoder: udigest::encoding::EncodeValue<B>,
+        ) {
+            let digits = value.to_digits::<u8>(rug::integer::Order::Msf);
+            encoder.encode_leaf_value(digits)
+        }
+    }
 
-/// Digests any encryption key
-///
-/// To be used within `#[udigest(with = "...")]` attribute
-pub fn digest_encryption_key<B: udigest::Buffer>(
-    value: &&dyn fast_paillier::AnyEncryptionKey,
-    encoder: udigest::encoding::EncodeValue<B>,
-) {
-    digest_integer::<B>(value.n(), encoder)
+    /// Digests any encryption key
+    pub struct AnyEncryptionKey;
+    impl udigest::DigestAs<&dyn fast_paillier::AnyEncryptionKey> for AnyEncryptionKey {
+        fn digest_as<B: udigest::Buffer>(
+            value: &&dyn fast_paillier::AnyEncryptionKey,
+            encoder: udigest::encoding::EncodeValue<B>,
+        ) {
+            Integer::digest_as(value.n(), encoder)
+        }
+    }
 }
 
 /// A common logic shared across tests and doctests

src/group_element_vs_paillier_encryption_in_range.rs

@@ -118,7 +118,7 @@ pub struct SecurityParams {
     /// Epsilon in paper, slackness parameter
     pub epsilon: usize,
     /// q in paper. Security parameter for challenge
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub q: Integer,
 }
 
@@ -127,10 +127,10 @@ pub struct SecurityParams {
 #[udigest(bound = "")]
 pub struct Data<'a, C: Curve> {
     /// N0 in paper, public key that C was encrypted on
-    #[udigest(with = crate::common::digest_encryption_key)]
+    #[udigest(as = crate::common::encoding::AnyEncryptionKey)]
     pub key0: &'a dyn AnyEncryptionKey,
     /// C in paper, logarithm of X encrypted on N0
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub c: &'a Ciphertext,
     /// A basepoint, generator in group
     pub b: &'a Point<C>,
@@ -152,12 +152,12 @@ pub struct PrivateData<'a> {
 #[udigest(bound = "")]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize), serde(bound = ""))]
 pub struct Commitment<C: Curve> {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub s: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub a: Ciphertext,
     pub y: Point<C>,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub d: Integer,
 }
 

src/no_small_factor.rs

@@ -95,18 +95,18 @@ pub struct SecurityParams {
     /// Epsilon in paper, slackness parameter
     pub epsilon: usize,
     /// q in paper. Security parameter for challenge
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub q: Integer,
 }
 
 /// Public data that both parties know
 #[derive(Debug, Clone, Copy, udigest::Digestable)]
 pub struct Data<'a> {
     /// N0 - rsa modulus
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub n: &'a Integer,
     /// A number close to square root of n
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub n_root: &'a Integer,
 }
 
@@ -135,17 +135,17 @@ pub struct PrivateCommitment {
 #[derive(Debug, Clone, udigest::Digestable)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Commitment {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub p: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub q: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub a: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub b: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub t: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub sigma: Integer,
 }
 

src/paillier_affine_operation_in_range.rs

@@ -175,7 +175,7 @@ pub struct SecurityParams {
     /// Epsilon in paper, slackness parameter
     pub epsilon: usize,
     /// q in paper. Security parameter for challenge
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub q: Integer,
 }
 
@@ -184,19 +184,19 @@ pub struct SecurityParams {
 #[udigest(bound = "")]
 pub struct Data<'a, C: Curve> {
     /// N0 in paper, public key that C was encrypted on
-    #[udigest(with = crate::common::digest_encryption_key)]
+    #[udigest(as = crate::common::encoding::AnyEncryptionKey)]
     pub key0: &'a dyn AnyEncryptionKey,
     /// N1 in paper, public key that y -> Y was encrypted on
-    #[udigest(with = crate::common::digest_encryption_key)]
+    #[udigest(as = crate::common::encoding::AnyEncryptionKey)]
     pub key1: &'a dyn AnyEncryptionKey,
     /// C or C0 in paper, some data encrypted on N0
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub c: &'a Ciphertext,
     /// D or C in paper, result of affine transformation of C0 with x and y
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub d: &'a Integer,
     /// Y in paper, y encrypted on N1
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub y: &'a Ciphertext,
     /// X in paper, obtained as g^x
     pub x: &'a Point<C>,
@@ -221,18 +221,18 @@ pub struct PrivateData<'a> {
 #[udigest(bound = "")]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize), serde(bound = ""))]
 pub struct Commitment<C: Curve> {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub a: Integer,
     pub b_x: Point<C>,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub b_y: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub e: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub s: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub f: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub t: Integer,
 }
 

src/paillier_blum_modulus.rs

@@ -65,7 +65,7 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Clone, udigest::Digestable)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Data {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub n: Integer,
 }
 
@@ -80,7 +80,7 @@ pub struct PrivateData {
 #[derive(Debug, Clone, udigest::Digestable)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Commitment {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub w: Integer,
 }
 

src/paillier_encryption_in_range.rs

@@ -113,10 +113,10 @@ pub struct SecurityParams {
 #[derive(Debug, Clone, Copy, udigest::Digestable)]
 pub struct Data<'a> {
     /// N0 in paper, public key that k -> K was encrypted on
-    #[udigest(with = crate::common::digest_encryption_key)]
+    #[udigest(as = crate::common::encoding::AnyEncryptionKey)]
     pub key: &'a dyn AnyEncryptionKey,
     /// K in paper
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = &crate::common::encoding::Integer)]
     pub ciphertext: &'a Ciphertext,
 }
 
@@ -134,11 +134,11 @@ pub struct PrivateData<'a> {
 #[derive(Debug, Clone, udigest::Digestable)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Commitment {
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub s: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub a: Integer,
-    #[udigest(with = crate::common::digest_integer)]
+    #[udigest(as = crate::common::encoding::Integer)]
     pub c: Integer,
 }